Medical Term Glossary
Plain-language explanations of the medical terms that appear on CT, MRI and X-ray reports — what each one means, when it matters, and what to ask your doctor.
A
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Abscess
A walled-off pocket of pus that the body builds around an infection to stop it spreading. It is the immune system's way of containing trouble, but once it forms it usually cannot drain on its own. Most need either antibiotics, a drain placed under image guidance, or a small procedure to clear them properly.
Also: infected cavity, infected fluid collection, pocket of pus
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Acetabulum
The hip socket — the cup-shaped hollow in the side of the pelvis that cradles the ball at the top of the thigh bone. Together they form the ball-and-socket hip joint. On a report it is usually just naming the socket side of the hip. The word itself is plain anatomy.
Also: acetabula, hip joint socket, hip socket
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Achilles tendon
The thick, strong cord at the back of the ankle that joins the calf muscles to the heel bone. It lets you push off, rise on your toes, and absorb force when walking or running. Reports mention it when describing thickening, inflammation, or a tear, best seen on MRI or ultrasound.
Also: Achilles, calcaneal tendon, heel cord
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Acromion
This is the bony tip at the very top of your shoulder, the firm bump you can feel where the shoulder blade reaches over toward the collarbone. It forms a small roof above the shoulder joint. Reports name it to point to that top-of-shoulder spot when describing a finding.
Also: acromial process, acromial tip, shoulder blade tip
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Adrenal gland
A small, triangular hormone-producing organ sitting on top of each kidney. It releases stress hormones such as cortisol and adrenaline, along with chemicals that help the body manage salt, water, and blood pressure. Small spots found here by chance on a scan are extremely common and the vast majority turn out to be harmless.
Also: adrenal, adrenals, gland above the kidney
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Air bronchogram
A pattern where air-filled airways show up as dark branching lines against a brighter, denser background of lung. Normally these small airways blend in; they only stand out when the lung tissue around them fills with fluid or cells. It is a sign, not a disease, and most often points to ordinary causes like pneumonia.
Also: air bronchograms, air filled bronchi sign, branching air sign
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Aneurysm
A focal bulge in the wall of an artery, where the vessel has stretched outwards into a balloon-like pouch. Most are found by chance on scans done for another reason and are watched over years rather than treated immediately. Size, location, and growth rate decide whether monitoring, medication, or repair is the right plan.
Also: AAA, arterial aneurysm, ballooning artery
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Aorta
The body's largest artery. It carries oxygen-rich blood out of the heart, arches over the top of the chest, and then runs straight down through the chest and belly, branching off to supply every organ and limb along the way. Reports often mention it when measuring its width or describing changes in its wall.
Also: abdominal aorta, aortic vessel, great artery
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Ascites
Extra fluid that has collected inside the belly, in the space surrounding the bowel and organs. A small amount can be normal in some situations, but larger collections almost always point to a problem with the liver, heart, kidneys, or the lining of the abdomen itself. The cause matters far more than the fluid.
Also: abdominal effusion, abdominal fluid, fluid build-up in the belly
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Atelectasis
A small area of lung that has not fully inflated, so it looks denser than the air-filled tissue around it. It is one of the most common findings on a chest CT and is usually mild, temporary, and not a sign of disease on its own. The cause matters more than the finding itself.
Also: bibasilar atelectasis, collapsed lung, discoid atelectasis
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Atrophy
Loss of size or volume in a tissue or organ. It can affect the brain, muscles, kidneys, a gland, or almost anywhere else. Some volume loss is part of normal ageing; some reflects a specific condition such as disuse, nerve damage, reduced blood supply, or a longstanding disease. The pattern matters more than the word alone.
Also: atrophic change, reduced volume, shrinkage
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Basal ganglia
A cluster of structures sitting deep inside the brain, on both sides, that help coordinate smooth, planned movements and certain types of learning and habit. They are routinely checked on every brain scan because they are a common site for small strokes, mineral deposits, and changes seen in some long-standing conditions.
Also: caudate putamen globus pallidus, deep brain nuclei, deep gray matter
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Benign
A reassuring word in radiology meaning a finding is not cancerous. It describes growths, lumps, or spots that have the visual features of harmless tissue — smooth edges, slow or no growth, typical patterns. Some still need monitoring or treatment depending on size and location, but they are not cancer.
Also: benign-appearing, harmless, likely benign
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Biliary dilatation
A widening of the small tubes that carry bile from the liver to the bowel. It usually means something downstream is slowing or blocking the flow — a stone, a narrowing, an inflamed pancreas, or, less often, a mass. The location and degree of the widening tell the medical team where to look next.
Also: bile duct dilation, biliary dilation, biliary tree dilation
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Bone marrow edema
An area inside a bone where extra fluid has built up among the soft tissue that fills its core. It usually signals that the bone is reacting to something — a recent injury, repeated stress, inflammation, or a nearby joint problem — and shows up as a bright patch on MRI sequences sensitive to water.
Also: bone bruise, bone marrow edema syndrome, bone marrow lesion
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Bowel obstruction
A blockage that stops food, fluid, and gas from moving through the intestines as they normally would. The gut above the block stretches and fills with fluid and air, which is what shows up on a scan. It is almost always a problem that needs prompt medical attention, sometimes urgent surgery.
Also: blocked bowel, blocked intestine, gut blockage
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Brainstem
The stalk-like lower part of the brain that connects the larger brain above to the spinal cord below. It runs the basic, automatic functions the body cannot live without — breathing, heart rate, blood pressure, swallowing, and the level of wakefulness. Every brain scan checks this region carefully because of how vital it is.
Also: brain stalk, brain stem, lower brain stalk
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Bronchi
The branching airways that carry air from the windpipe into and through each lung, dividing again and again like tree branches into ever-smaller tubes. Reports comment on them when their walls look thickened, when they appear widened, or when something is blocking the flow of air through them.
Also: air tubes, airways, bronchial
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Bronchiectasis
Permanently widened airways in the lungs. The tubes that should taper smoothly as they branch deeper instead look stretched and baggy, which makes it harder to clear mucus and easier for infections to take hold. The damage itself does not reverse, but the symptoms it causes can usually be managed well with the right treatment.
Also: airway dilatation, bronchial dilatation, cylindrical bronchiectasis
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Bursa
A small, flat fluid-filled sac that sits between tissues such as tendon and bone, acting as a cushion so they glide without rubbing. Bursae are found around the shoulder, hip, knee, and elbow. Reports mention them when describing fluid or inflammation, called bursitis, best seen on MRI or ultrasound.
Also: bursae, bursal sac, fluid cushion
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Bursitis
Inflammation of a bursa — one of the small fluid-filled cushions that sit between bone and the soft tissues around joints. When a bursa becomes irritated, it fills with extra fluid and shows up on imaging as a fluid pocket. Most cases settle with rest and time; a smaller number are infected and need treatment.
Also: bursa inflammation, bursal distension, bursal inflammation
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Calcaneus
The heel bone — the large, sturdy bone at the back of your foot that you stand and land on. It forms the heel and anchors the Achilles tendon from your calf. On a report it is usually just naming the back of the foot. The word itself is plain anatomy.
Also: calcanei, heel, heel bone
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Calcification
A small deposit of calcium that has built up in soft tissue, blood vessels, or an old healed area. On a CT scan it shows up as a very bright white spot because calcium blocks x-rays. Most deposits are old, stable, and harmless — they are essentially scars made of mineral.
Also: calcifications, calcified, calcified lesion
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Calvarium
The dome-shaped top part of the skull — the smooth bony cap that covers and protects the brain. It does not include the bones of the face or the base of the skull. Radiologists use the word to point specifically at the upper skull bone when describing its thickness, shape, or any findings within it.
Also: calvaria, cranial vault, dome of the skull
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Cardiac silhouette
The outline of the heart as it appears on a chest image, seen as a solid shadow because the heart is full of blood and blocks the rays. Radiologists study its size and shape to judge whether the heart looks normal. The word describes the shadow, not a problem in itself.
Also: cardiac outline, cardiac shadow, heart outline
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Cardiomegaly
An enlarged heart on imaging. The heart looks bigger than expected when compared with the inside of the chest. It is a sign, not a diagnosis — the heart can grow because its walls have thickened from years of high blood pressure, because its chambers have stretched from extra workload, or because fluid has built up around it.
Also: big heart on scan, cardiac enlargement, dilated heart
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Cardiothoracic ratio
A simple comparison of the heart's width to the width of the chest on a chest X-ray, written as a fraction or percentage. A value up to about half is generally considered normal. It is a rough screening number, easily thrown off by how the image was taken, not a precise measure of heart health.
Also: CT ratio chest x-ray, CTR, cardio-thoracic ratio
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Carina
The ridge at the point where the windpipe splits into the two main airways, one heading to each lung. It sits in the middle of the chest behind the breastbone. Radiologists use it as a fixed landmark, and check that nearby structures and any breathing tubes are sitting in the right place.
Also: airway fork, carina of trachea, tracheal bifurcation
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Carpal bones
These are the eight small bones of your wrist, packed in two rows between the forearm and the hand. They let your wrist bend, tilt, and rotate smoothly. Reports name them to point to the wrist region, or to a specific little wrist bone, when describing a finding.
Also: carpals, carpus bones, small wrist bones
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Cartilage
The smooth, slippery tissue that caps the ends of bones inside a joint and cushions them so they glide without grinding. It also forms structures like the meniscus, ear, and windpipe rings. Reports mention it when describing thinning, wear, or damage, best seen on MRI.
Also: articular cartilage, chondral surface, gristle
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Cecum
The first, pouch-like part of the large bowel, sitting low in the right side of the belly where the small intestine empties in. The appendix hangs from it. Its name comes from a word meaning blind, as it is a dead-end pouch. Reports often name it to locate a finding in the lower right belly.
Also: blind pouch of colon, caecum, cecal pouch
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Cerebellum
The smaller, rounded part of the brain tucked under the back of the larger hemispheres, just above where the neck meets the skull. It coordinates balance, posture, and the smooth timing of movements. Radiologists mention it routinely on brain imaging because it is one of the standard structures they check on every scan.
Also: balance center of the brain, cerebellar, hindbrain coordinator
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Cerebral atrophy
A general shrinking of brain tissue, with widened grooves on the surface and slightly larger fluid spaces in the centre. A small amount is a normal part of getting older. Larger amounts, or shrinkage that does not match a person's age, can be linked to specific neurological conditions and are usually viewed alongside symptoms.
Also: age-related atrophy, brain atrophy, brain shrinkage
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Cerebral edema
Extra water inside or around the brain tissue, making part of the brain look swollen on a scan. It is a reaction to many things — a bruise, a stroke, an infection, a tumour, or surgery — rather than a diagnosis by itself. How much swelling there is, and what is causing it, decides how worrying it is.
Also: brain edema, brain swelling, cerebral oedema
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Chronic
A radiology word meaning a finding has been present for a long time — usually weeks, months, or years — and looks stable rather than new. It is the opposite of acute, which describes something that has just appeared. The word says nothing about danger; it describes how long something has been there.
Also: chronic changes, established, long-standing
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Clavicle
The collarbone — the slim, slightly S-shaped bone you can feel running across the top of your chest from the breastbone to the shoulder. It props the shoulder out to the side and links the arm to the body. On a report it is usually just naming where near the shoulder or upper chest a finding sits.
Also: clavicles, collar bone, collarbone
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Coccyx
The tailbone — the small, triangular tip at the very bottom of the spine, just below the sacrum. It is the leftover of what would be a tail, made of a few tiny fused bones. On a report it is usually just naming the lowest point of the spine. The word itself is plain anatomy.
Also: bottom of the spine, coccygeal bone, tail bone
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Collateral ligament
A strong band along the side of a joint that stops it bending sideways. In the knee, the MCL runs on the inner side and the LCL on the outer side. Similar ligaments brace the elbow and ankle. Reports mention them when describing a sprain or tear, best seen on MRI.
Also: LCL, MCL, collateral ligaments
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Compression fracture
A break in one of the spine's bones where the front of the bone has collapsed and lost height, while the back wall typically stays intact. Most happen in the mid or lower back, and many occur from a small load — like a cough or a minor stumble — in bone that has been weakened by osteoporosis.
Also: VCF, collapsed vertebra, crushed vertebra
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Condyle
This is the smooth, rounded knob at the end of a bone where it meets another bone to form a joint. You have them at the knee, elbow, jaw, and more. Reports use the word to point to that bulging, rounded end of a particular bone when describing a finding.
Also: bone knob, condyles, knuckle of bone
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Consolidation (lung)
An area of lung where the tiny air sacs are filled with something other than air — usually fluid, pus, blood, or inflammatory cells. On imaging it looks denser and whiter than normal lung, and pneumonia is the most familiar cause. The pattern, location, and your symptoms together point to what is filling those air spaces.
Also: airspace disease, airspace opacity, dense lung opacity
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Contrast enhancement
A special dye is injected into a vein during the scan to make blood vessels and certain tissues stand out more clearly. When an area soaks up the dye and looks brighter than its surroundings on the images, radiologists call that pattern enhancement. The pattern itself helps tell different kinds of tissue apart.
Also: IV contrast, contrast uptake, contrast-enhanced scan
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Cortical bone
The hard, dense outer layer of bone — the part you would feel if you tapped a bone with your knuckle. It surrounds and protects the softer, spongy inner bone (called trabecular or medullary bone). Most of the strength of a bone comes from this outer shell, and radiologists pay close attention to it for fractures.
Also: bone cortex, compact bone, cortex
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Costophrenic angle
The sharp corner at the bottom edge of each lung, where the curved chest wall meets the dome of the breathing muscle below. On a normal scan this corner looks crisp and pointed. Radiologists watch it closely because it is one of the first places fluid or scarring tends to show up.
Also: CP angle, costophrenic angles, costophrenic recess
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Cruciate ligament
One of two strong bands deep inside the knee that cross each other like an X and stop the shin bone sliding too far forward or back on the thigh bone. The front one is the ACL, the back one the PCL. Reports mention them when describing a sprain or tear, best seen on MRI.
Also: ACL, PCL, anterior cruciate ligament
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Cyst
A small sac filled with fluid, sitting inside an organ or in soft tissue. Most are harmless, very common, and pop up incidentally on scans done for other reasons. Radiologists describe them as simple when the fluid is clear and the walls are thin, which is the reassuring picture; complex ones earn a closer look.
Also: complex cyst, cystic lesion, fluid collection
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Degenerative changes
A general term radiologists use for the everyday wear-and-tear that accumulates in the spine over a lifetime — slightly flattened cushions between vertebrae, small bony ridges along the edges, and a bit of joint thickening. Extremely common after the mid-30s and found in plenty of people who have no back pain at all.
Also: age-related changes, degeneration, degenerative disease
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Deltoid
The large triangular muscle that caps the outer shoulder and gives it its rounded shape. It is the main muscle that lifts the arm out, forward, and back. Reports mention it when describing the muscle bulk, a strain, or, less commonly, a tear, usually best seen on MRI.
Also: deltoid muscle, deltoids, outer shoulder muscle
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Diaphragm
The large dome-shaped muscle that separates the chest from the belly and does most of the work of breathing. It flattens to pull air in and relaxes to let it out. Reports describe its position and outline, since a raised or unusually shaped dome can hint at something above or below it.
Also: breathing muscle, diaphragm dome, diaphragm muscle
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Diffusion-weighted imaging (DWI)
A special MRI sequence that measures how freely water molecules move inside tissue. When water movement is blocked — for example, in the first minutes of a stroke or inside very dense tissue — the area lights up brightly on the scan. It is one of the most sensitive tools in emergency brain imaging.
Also: ADC map, DWI, DWI sequence
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Disc bulge
A gentle, broad outward swell of one of the soft cushions that sit between the bones of the spine. The cushion stays intact — nothing has torn or leaked — but its outer edge pushes a little past its usual footprint. Extremely common with age and often found in people who have no symptoms at all.
Also: annular bulge, broad-based bulge, bulging disc
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Disc herniation
A small tear in the outer wall of one of the spinal cushions has let some of the soft inner core push outward into a focused lump. Unlike a broad, even bulge, this is a localized pocket that can press on a nearby nerve and cause arm or leg pain, tingling, or weakness along the nerve's path.
Also: disc extrusion, disc protrusion, herniated disc
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urgent
Dislocation
A joint where the bones are no longer lined up the way they should be. In the full form the bone surfaces have lost contact completely; in a partial form (subluxation) they are misaligned but still touch. Most need to be put back into place promptly, although the urgency varies by joint and whether nearby structures are injured.
Also: dislocated joint, displaced joint, joint displacement
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Diverticulosis
Small pouches that bulge outward from the wall of the large intestine, most often in the lower-left part. They are extremely common after middle age, usually cause no symptoms, and are typically found by chance on a scan or colonoscopy. They only become a concern if one of the pouches becomes inflamed or bleeds.
Also: bowel pouches, colon pouches, colonic diverticulosis
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Duodenum
The first, C-shaped part of the small intestine, just past the stomach. It receives food from the stomach and mixes it with juices from the pancreas and gallbladder to start digestion. Its name comes from a word for twelve fingers, its rough length. Reports often name it to locate a finding in the upper belly.
Also: C-loop of small bowel, duodenal loop, duodenal segment
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Effacement
The flattening or smoothing away of a normal space, fold, or outline that should be visible on a scan, usually because something nearby is pressing on it. It is a sign of crowding or pressure, and how concerning it is depends entirely on where it occurs.
Also: compression of a space, effaced, flattening
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Emphysema
Permanent damage to the tiny air sacs deep inside the lungs, where the walls between them have broken down and merged into bigger, less efficient pockets. On a CT scan it shows up as small black spaces scattered through the lung. Smoking is by far the most common cause, though some people develop it for other reasons.
Also: COPD changes, bullous emphysema, centrilobular emphysema
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Extra-axial
A location word meaning outside the brain tissue itself but still inside the skull — in the protective layers and spaces wrapped around the brain. Radiologists use it to separate findings sitting on or around the surface from those buried in the brain. The distinction matters because it often points to different causes and treatments.
Also: around the brain, extra axial, extra-axial compartment
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Facet joint
One of the small paired joints at the back of each level of the spine that link one vertebra to the next. They guide and limit movement — bending, twisting, leaning back — and share load with the disc at the front. Like every joint in the body, they can show wear over time.
Also: apophyseal joint, facet, facet arthropathy
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Femur
The thigh bone — the long, strong bone running from your hip down to your knee. It is the largest and strongest bone in the body, carrying your full weight with every step. On a report it is usually just naming where in the thigh or hip a finding sits. The word itself is plain anatomy.
Also: femora, thigh bone, thighbone
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Fibula
The calf bone — the thin, long bone running down the outer side of your lower leg, alongside the thicker shinbone. It carries little body weight but steadies the leg and forms the bony bump on the outer ankle. On a report it is usually just naming where in the lower leg a finding sits.
Also: calf bone, lower leg bone, outer leg bone
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FLAIR hyperintensity
A bright spot or patch on a specific type of MRI image that is good at picking up subtle tissue changes. The brightness itself simply means the tissue holds a little more water than its neighbours. Such spots are extremely common, often age-related, and only meaningful when read together with their pattern, size, and the person's symptoms.
Also: FLAIR bright lesions, FLAIR hyperintensities, T2 FLAIR hyperintensity
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Focal
A descriptive word meaning a finding is limited to one specific spot rather than spread across a wider area. It is the opposite of diffuse, which means scattered or widespread. The word says where, not what — it tells you the finding is localised but says nothing on its own about whether it matters.
Also: circumscribed, discrete area, in one area
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Foraminal narrowing
A tightening of one of the small side-doors of the spine that each nerve uses to leave the spinal canal and travel out to the body. When the door is smaller than usual, the nerve passing through can be pinched, leading to pain, tingling, or weakness along that nerve's path — usually on one side.
Also: exit foramen narrowing, foraminal stenosis, narrowing of the nerve exit
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Fracture
A break, crack, or other loss of continuity in a bone. It can be a hairline split that's barely visible, a clean snap across the middle, or a more complicated pattern with multiple pieces. The location, pattern, and whether nearby structures are involved all shape how it is treated.
Also: Fx, bone break, bony injury
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Gallbladder
A small pear-shaped sac tucked under the liver that stores and concentrates bile, the greenish fluid the liver makes to help break down fats. It releases that bile into the small intestine after a fatty meal. People can live normally without it if it has to be removed, which is one of the most common abdominal surgeries.
Also: bile sac, bile storage pouch, biliary sac
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Gallstones
Small, hardened deposits that form inside the gallbladder — the little pear-shaped sac that stores bile beneath the liver. Many people have them without ever knowing, and a quiet stone often needs no treatment. They only become a medical problem when one moves, blocks a duct, or sets off inflammation.
Also: biliary stones, cholecystolithiasis, cholelithiasis
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Gastric
Anything to do with the stomach. It is simply the medical adjective for 'relating to the stomach', from the Greek word for stomach. On its own it carries no good or bad meaning — it just tells you which organ a finding involves. The noun attached to it, like wall or folds, is what actually matters.
Also: of the stomach, pertaining to the stomach, relating to the stomach
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Glenoid
This is the shallow socket of your shoulder, the cup on the shoulder blade that the round top of the arm bone sits in. It is the dish side of the shoulder's ball-and-socket joint. Reports name it to point to the socket part of the shoulder when describing a finding.
Also: glenoid cavity, glenoid fossa, shoulder cup
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Ground-glass opacity
A hazy area of lung on CT that looks like a faint cloud — denser than normal lung but not so dense that the underlying blood vessels and airways disappear. It is a non-specific finding with a long list of possible causes, ranging from a minor passing infection to inflammation, fluid, or early scarring. Context is everything.
Also: GGO, ground glass attenuation, ground glass changes
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Hemidiaphragm
One half of the dome-shaped breathing muscle that floors the chest, either the left or the right side. Each lung rests on its own half. Reports name it to specify which side they are describing, most often when one dome sits higher than the other or has an unusual outline.
Also: diaphragm half, hemi-diaphragm, hemidiaphragms
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urgent
Hemorrhage
Blood that has leaked outside the vessels meant to carry it. On a scan it shows up as a pool or streak of blood in tissue or a body cavity. Size, location, and whether the leak looks fresh or old all change how urgently it needs attention. Many small or old collections are watched rather than treated.
Also: active bleed, bleed, bleeding
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Hepatic
Anything to do with the liver. It is simply the medical adjective for 'relating to the liver', from the Greek word for liver. On its own it carries no good or bad meaning — it just tells you which organ a finding involves. The noun attached to it, like cyst or lesion, is what actually matters.
Also: liver, liver-related, of the liver
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normal
Hepatic cyst
A small, fluid-filled pocket sitting inside the liver. The vast majority are harmless, present from birth, and stay quiet for life. Many people have one without ever knowing — they tend to be found by chance on a scan ordered for something completely unrelated, and they rarely cause symptoms.
Also: benign liver cyst, biliary cyst, cyst in the liver
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Hepatic flexure
The sharp bend in the large bowel in the upper right belly, just under the liver, where the colon turns from heading up to running across. Hepatic means relating to the liver, its near neighbour. Reports often name it to locate a finding at this corner of the colon.
Also: colon bend near liver, hepatic colonic flexure, right colic flexure
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Hepatic steatosis
Extra fat stored inside the cells of the liver. It is very common, often has no symptoms, and is usually picked up by chance on imaging done for other reasons. The amount of fat and the reason behind it — diet, weight, alcohol, or certain medications — guide how much it matters.
Also: MASLD, NAFLD, fat in the liver
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Hilum
The central region on each side of the chest where the main blood vessels, the large airway, and lymph nodes enter and leave the lung. There is one on the left and one on the right. Reports comment on it when checking whether these structures look normal in size and density.
Also: hila, hilar, hilar region
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Humerus
The upper arm bone — the long bone running from your shoulder down to your elbow. Its rounded top forms the ball of the shoulder joint, and its lower end helps build the elbow. On a report it is usually just naming where in the upper arm a finding sits. The word itself is plain anatomy.
Also: arm bone, humeri, upper arm
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Hydrocephalus
A build-up of cerebrospinal fluid inside the brain's fluid chambers, making them larger than normal. It can develop slowly or come on quickly, and the cause matters far more than the word itself. Treatment ranges from watchful waiting to a small surgical drain, depending on how much pressure the extra fluid creates.
Also: CSF build-up, NPH, communicating hydrocephalus
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Hydronephrosis
A swelling of one or both kidneys caused by urine that cannot drain away properly. The backed-up fluid stretches the kidney's collecting system, which shows up clearly on imaging. The cause matters more than the swelling itself — kidney stones, narrowed tubes, and an enlarged prostate are typical reasons.
Also: dilated renal pelvis, kidney backup, kidney swelling
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Ileum
The last and longest section of the small intestine, leading into the large bowel in the lower right belly. It absorbs remaining nutrients, vitamin B12, and bile salts. Not to be confused with the ilium, a hip bone. Reports often name it to locate a finding in the lower small bowel.
Also: final small bowel, ileal loops, last small intestine
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Ilium
The hip bone — the large, broad, fan-shaped bone that forms the upper, flaring part of the pelvis. Its top edge is the crest you rest your hands on at your waist. On a report it is usually just naming the upper pelvis. The word itself is plain anatomy.
Also: hip bone, ilia, iliac bone
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Imaging planes (axial, sagittal, coronal)
The three standard directions radiologists use to slice the body when reviewing a scan. Axial slices cut across like a horizontal cross-section, sagittal slices run from side to side splitting left from right, and coronal slices run front to back like opening a book. Looking at the same area in all three helps the radiologist see things any single direction would miss.
Also: axial, axial view, coronal
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Impingement
A radiology word for pinching — when two structures inside a joint rub or compress each other during normal movement instead of gliding cleanly past each other. Most often described in the shoulder (between the bones at the top) and the hip (between the ball and the rim of the socket), and not always painful.
Also: FAI, femoroacetabular impingement, hip impingement
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Incidental finding
Something the radiologist noticed on a scan even though it was not what the scan was originally looking for. These pop-ups are very common in modern imaging because scans capture far more than the clinical question asked. Most are harmless background discoveries; a few deserve a closer look.
Also: additional finding, incidental lesion, incidentally noted
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Indeterminate
A careful word radiologists use when a finding doesn't fit neatly into the benign category or the worrying category. It means the current scan alone cannot decide what something is, so a follow-up scan or a different test is usually recommended. It does not mean the finding is dangerous.
Also: equivocal finding, incompletely characterised, indeterminate finding
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urgent
Infarct
An area of brain tissue that has been injured or has died because its blood supply was cut off, usually by a blocked artery. On imaging it shows up as a patch of tissue that no longer looks like its healthy neighbours. The size and location decide how the symptoms appear and how the team responds.
Also: brain attack, cerebral infarct, infarction
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Inferior vena cava
The body's largest vein in the lower half of the body. It collects oxygen-poor blood from the legs, belly, and pelvis and carries it up to the heart. Often shortened to IVC. Radiologists mention it when measuring its width or describing how full or collapsed it looks.
Also: IVC, great lower vein, lower vena cava
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Infraspinatus
One of the four rotator cuff muscles, sitting across the back of the shoulder blade. It turns the arm outward and helps hold the ball of the arm bone in its socket. Reports mention it when describing wear, inflammation, or a tear in its tendon, usually best seen on MRI.
Also: infraspinatus muscle, infraspinatus tendon, rotator cuff muscle
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Intracranial
An adjective meaning inside the skull. It describes the location of something — a structure, a finding, or a process — rather than what that thing is or whether it is a problem. The word appears constantly in brain reports because radiologists use it to point at where something sits.
Also: inside the brain cavity, inside the skull, intracranial compartment
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urgent
Intracranial hemorrhage
Blood that has leaked inside the skull, either into the brain tissue itself or into one of the spaces wrapped around it. It is an important and time-sensitive finding because fresh blood takes up room the brain does not have to spare. Exact location, size, and cause shape how urgently it has to be treated.
Also: ICH, bleeding in the brain, brain bleed
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Ischium
This is the lower, back part of your pelvis, the bone you actually sit on. Each side has a rounded knob, often called the sit bone, that takes your weight in a chair. Reports name it to point to that lower rear part of the pelvis when describing a finding.
Also: ischial bone, lower pelvic bone, os ischii
J
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Jejunum
The middle section of the small intestine, between the duodenum just past the stomach and the ileum further down. This is where most of the nutrients from your food are absorbed. It mainly sits in the upper left belly. Reports often name it to locate a finding within the small bowel.
Also: jejunal loops, jejunal segment, mid small intestine
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Joint effusion
Extra fluid inside the capsule that wraps around a joint. A small amount of fluid is normal and keeps the joint lubricated; a larger amount usually signals that something has stirred up the lining — an injury, arthritis, infection, gout, or inflammation — and is making more fluid than the joint can absorb.
Also: fluid in the joint, fluid on the knee, intra-articular effusion
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normal
Joint space narrowing
A reduced gap between the two bones of a joint on x-ray, which usually means the cushioning cartilage between them has thinned. It is one of the most common signs of ordinary joint wear and ageing, and is very often mild, gradual, and manageable rather than alarming.
Also: cartilage thinning, joint space loss, loss of joint space
K
L
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Labral tear
A break in the labrum, the ring of soft fibrous cartilage that deepens the socket of the shoulder or hip and helps hold the ball of the joint in place. Tears can come from a sudden injury, from repeated load over years, or simply from the shape of the joint itself. Common, and often found on scans of pain-free adults.
Also: SLAP tear, hip labral tear, labrum tear
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Labrum
A rim of firm cartilage that deepens the shallow sockets of the shoulder and hip, helping to grip the ball of the joint and keep it stable. Reports mention it when describing a fray, a tear, or age-related wear of this rim, which is best seen on MRI.
Also: cartilage rim, glenoid labrum, hip labrum
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Lamina
A flat plate of bone that forms the back wall of each vertebra, completing the bony ring that protects the spinal cord. The two laminae meet in the middle and join the bump you can feel along your back. Reports often name them to locate a finding or after surgery that removes part of this bone.
Also: bony arch, laminae, spinal lamina
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Larynx
The voice box — the structure in the front of the neck that holds the vocal cords and sits at the top of the windpipe. It lets you speak, guards the airway when you swallow, and routes air to the lungs. Radiologists name it to locate findings in this part of the throat.
Also: Adam's apple, laryngeal region, throat voice box
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Lesion
A general word radiologists use for any spot, area, or region of tissue that looks different from what surrounds it. By itself it does not mean cancer, infection, or anything specific — it simply flags a finding that stood out. The report's other adjectives (focal, well-defined, suspicious, benign) carry most of the meaning.
Also: abnormal area, focal lesion, growth
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Ligament tear
A break in one of the tough fibrous bands that hold two bones together at a joint. Tears range from a few stretched fibres (a sprain) to a complete rupture across the whole band. Most happen during a sudden twist, pivot, or impact, and the joint involved shapes how serious it is.
Also: ACL tear, MCL tear, ligament rupture
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Lucency
A darker, less dense-looking area on an x-ray or CT, where more of the beam passed through than in the tissue around it. It is a neutral description of an appearance, not a diagnosis — common harmless causes include air or fat, while in bone it can sometimes need a closer look.
Also: dark area on x-ray, decreased density, low density area
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Lung apex
The rounded top of each lung, the highest part that reaches up behind the collarbone toward the base of the neck. There is one on each side. Reports look here for scarring, old infection, fluid, or small changes, since this corner can be subtle and easy to overlook.
Also: apex of the lung, apical, apices
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Lung markings
The fine network of branching lines seen spreading through the lungs on an image, mostly the small blood vessels and airways. Their presence and pattern are normal. Reports comment when they look increased, reduced, or crowded, since the pattern can shift with fluid, scarring, or trapped air.
Also: bronchovascular markings, interstitial markings, lung pattern
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Lymph nodes
Small, bean-shaped filters that sit along the body's drainage network for tissue fluid. Hundreds of them are scattered through the neck, armpits, chest, abdomen, pelvis, and groin. They trap bacteria, viruses, debris, and stray cells, then mount an immune response. Their presence on a scan is normal; size, shape, and pattern decide whether they need attention.
Also: glands, lymph glands, lymph node
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warning
Lymphadenopathy
Lymph nodes that look larger than normal on imaging. The body has hundreds of these small, bean-shaped filters scattered through the chest, neck, armpits, and elsewhere. They swell when they are doing their job — fighting infection — but can also enlarge from inflammation, autoimmune conditions, or, less commonly, cancer.
Also: enlarged lymph nodes, hilar lymphadenopathy, lymph node enlargement
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Lytic lesion
A spot where bone has been thinned or eaten away, leaving a darker hole-like area on an x-ray or CT. Many lytic areas are harmless cysts or normal variants, but because some have more serious causes, radiologists describe their edges carefully and often suggest a closer look.
Also: bone destruction, bone lysis, lucent bone lesion
M
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Malalignment
Bones or joints that do not line up in their normal position or angle on a scan. It is a broad descriptive term covering anything from minor age-related shifts and old healed injuries to fresh injuries needing attention, so its importance depends on the cause and site.
Also: abnormal alignment, alignment abnormality, bones out of alignment
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urgent
Malignant
A heavy word in radiology meaning a finding has the appearance of cancer on imaging — irregular edges, invasion into nearby tissue, abnormal blood vessels, or other concerning features. It is a description of the picture, not a confirmed diagnosis. A biopsy is what actually proves cancer; imaging alone cannot.
Also: cancerous, concerning for cancer, concerning for malignancy
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Malleolus
These are the two bony bumps on the sides of your ankle, the knobs you can feel and see on the inner and outer ankle. They are the lower tips of the shin bones that cradle the ankle joint. Reports name them to point to one of those ankle bumps when describing a finding.
Also: ankle bone, ankle bone bump, ankle bump
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warning
Mass
A solid or partly solid lump of tissue, usually larger than three centimetres, that looks distinct from the tissue around it. The word flags something worth investigating, but it does not by itself mean cancer. Size, borders, growth over time, and how it behaves with contrast all carry far more meaning than the label alone.
Also: focal mass, growth, lump
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Mass effect
A phrase radiologists use when something inside the skull is taking up extra room and pushing on the brain tissue or fluid spaces nearby. It is a description of crowding, not a diagnosis on its own. The cause — swelling, bleeding, a tumour, or a fluid pocket — and how much pressure it creates is what matters most.
Also: compression effect, local mass effect, mass-like effect
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Mastoid air cells
Tiny honeycomb-like air pockets inside the bone just behind each ear, connected to the middle ear. They normally contain air and help regulate pressure in the ear. Because they sit right next to the brain, every head CT or MRI looks at them and notes whether they are clear or contain fluid.
Also: ear bone air spaces, mastoid, mastoid bone
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Mediastinal contour
The outline of the central zone of the chest, the strip between the two lungs that holds the heart, the great vessels, the windpipe, and lymph nodes. Radiologists trace its shape and width to check that this crowded middle region looks normal and nothing there is enlarged or pushed out of place.
Also: mediastinal borders, mediastinal margins, mediastinal outline
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Mediastinum
The central compartment of the chest, sitting between the two lungs. It contains the heart, the great blood vessels, the windpipe, the food pipe, lymph nodes, and several nerves. When a chest scan mentions this area, it is usually pointing at something sitting in that central region rather than in the lungs themselves.
Also: central chest compartment, central chest space, mediastinal area
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Meniscal tear
A split in one of the two C-shaped pads of cartilage that sit between the thigh bone and the shin bone inside the knee. These pads cushion and stabilise the joint. Tears can follow a sudden twist or develop gradually with age, and not every tear seen on a scan causes pain.
Also: bucket-handle tear, lateral meniscus tear, medial meniscus tear
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Meniscus
One of two C-shaped pads of cartilage inside the knee that sit between the thigh bone and the shin bone. They cushion the joint, spread load, and add stability. Reports mention them when describing wear, a tear, or age-related thinning, all best seen on MRI.
Also: knee cartilage, knee meniscus, lateral meniscus
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Metacarpal
These are the long bones inside the palm of your hand, the ones whose knuckles you see when you make a fist. There are five, one running from the wrist to the base of each finger. Reports name them simply to mark where in the hand a finding sits.
Also: hand bones, knuckle bones, metacarpal bones
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urgent
Metastasis
A spot on imaging that looks like cancer that has spread from another part of the body. The word on a report is a description of appearance, not always a diagnosis. Many suspected spreads turn out, after biopsy or follow-up, to be benign — cysts, scars, or unrelated lesions. Biopsy is the gold standard for confirmation.
Also: metastases, metastatic disease, metastatic lesion
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Metatarsal
These are the long bones in the middle of your foot, the ones you can feel under the top of the foot running from the arch toward the toes. There are five of them, one leading to each toe. Reports name them simply to point to where a finding sits in the foot.
Also: foot bones, long foot bones, metatarsal bones
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urgent
Midline shift
A sign on brain imaging that something on one side is pushing the brain's central structures over toward the other side. It almost always points to swelling, bleeding, or a mass that needs attention soon. The amount of shift, measured in millimetres, is one of the strongest cues to how urgent the situation is.
Also: brain shift, deviation of the midline, mass effect with midline shift
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MRI signal intensity (T1, T2, FLAIR)
On an MRI scan, every tissue gives off a different brightness depending on which setting the scanner is using. The settings are called sequences — T1, T2, and FLAIR are the most common. Whether something looks bright or dark on each sequence is one of the main clues radiologists use to tell different tissues and problems apart.
Also: FLAIR, T1, T1 signal
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MRI vs CT — which does what
Two of the most common imaging tests, used for different jobs. CT is fast and great for bones, bleeding, and emergencies. MRI is slower but shows soft tissue, brain detail, and joints in much higher resolution. Neither is better overall — they answer different questions, and doctors choose based on what they need to see.
Also: CT or MRI, CT vs MRI, MRI or CT
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Mucosal thickening
A description used by radiologists when the soft inner lining of a hollow space looks puffier than usual. It is most commonly seen in the sinuses but also turns up in the bowel and other lined cavities. By itself it just means the lining is irritated; the cause varies from a recent cold to a more persistent inflammation.
Also: lining thickening, mucosal swelling, sinus lining thickening
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Nasopharynx
The space at the very back of the nose, above the roof of the mouth, where the nasal passages meet the top of the throat. Air passes through it on its way from the nose to the lungs. Radiologists name it to pinpoint findings in this upper throat region behind the nose.
Also: back of nose, behind the nose, post-nasal space
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Nodule
A small, rounded spot of tissue, usually under three centimetres across, that looks different from what surrounds it. Most are harmless and very common — old scars, tiny benign growths, or healed inflammation. Size, shape, and behaviour over time decide whether one needs follow-up or can be ignored.
Also: pulmonary nodule, small focal lesion, small nodule
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Nonspecific
A hedging word radiologists use when a finding could be caused by several different things and the scan alone cannot decide between them. It is not a diagnosis — it is the radiologist being honest about the limits of imaging and asking your doctor to combine the picture with your symptoms and blood tests.
Also: etiology unclear, non-specific, nonspecific appearance
O
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Odontoid process
A small, tooth-shaped peg of bone rising from the second neck vertebra. The vertebra above pivots around it, letting you turn your head side to side to say no. Reports often name it when checking the upper neck after injury or to confirm the bone and its alignment look normal.
Also: C2 peg, dens, dens of C2
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Olecranon
This is the bony point of your elbow, the firm tip you lean on when you rest your elbow on a table. It is the upper end of the larger forearm bone, hooking around the back of the elbow joint. Reports name it to point to the elbow tip when describing a finding.
Also: elbow bone, elbow point, elbow tip
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Opacity
A whiter, denser-looking patch on an x-ray or CT, where something is blocking more of the beam than the surrounding tissue. It is a neutral description of an appearance, not a diagnosis — the cause can be anything from fluid or infection to scarring or a harmless overlap.
Also: dense area, density, increased density
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Orbits
The bony eye sockets in the front of the skull, holding the eyeballs along with the muscles, nerves, fat, and blood vessels that surround them. They sit right next to the sinuses and the front of the brain, so head and brain scans routinely include them and comment on what is inside.
Also: bony orbit, eye socket, eye sockets
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Oropharynx
The middle part of the throat that sits directly behind the mouth — the area you can partly see when you open wide and say 'aah'. It includes the back of the tongue, the tonsils, and the soft palate. Radiologists name it to locate findings in this central throat region.
Also: back of mouth, back of throat, middle throat
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Osseous
A medical word that simply means "of the bone" or "made of bone." Radiologists use it as a precise adjective when describing structures, findings, or changes that involve the skeleton itself rather than the surrounding soft tissues — muscles, tendons, organs, or nerves. On its own it carries no good or bad meaning.
Also: bone, bone-related, bony
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normal
Osteoarthritis
The most common form of joint wear. The smooth cartilage that lines the ends of the bones inside a joint gradually thins, the joint space narrows, and small bony ridges form along the edges. Extremely common with age — most adults over 60 show some of it on imaging, and many feel nothing from it.
Also: DJD, OA, degenerative arthritis
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normal
Osteophyte
A small extra ridge of bone that grows along the edge of a joint or vertebra as the body responds to years of wear and load. Very common after middle age, usually painless on its own, and most often a marker of ageing rather than a disease — though large ones can crowd nearby nerves.
Also: bone spur, bony outgrowth, bony ridge
P
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Paranasal sinuses
Air-filled spaces in the bones of the face around the nose, lightening the skull and warming and moistening the air you breathe. They sit in the forehead, behind the cheeks, between the eyes, and deep inside the head, and they all drain into the nose. Brain and head scans routinely include and comment on them.
Also: ethmoid sinus, facial sinuses, frontal sinus
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Parenchyma
The working tissue of an organ — the part that actually does the organ's job, as opposed to its supporting structures like blood vessels, ducts, or capsule. The brain has its own working tissue; so do the kidneys, liver, lungs, and pancreas. Radiologists use the word to be precise about which part of an organ they are describing.
Also: brain parenchyma, functional tissue, hepatic parenchyma
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Patella
The kneecap — the small, flat, roughly triangular bone that sits at the front of your knee. You can feel it move when you straighten your leg. It protects the knee joint and gives the big thigh muscle leverage to extend the leg. On a report it is usually just naming the front of the knee.
Also: knee bone, knee cap, kneecap
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Pedicle
A short, strong bridge of bone on each side of a vertebra that connects the round front body of the bone to the protective arch behind it. The pedicles form the side walls of the canal that shields the spinal cord. Reports often name them to locate a finding or to confirm the bone looks intact.
Also: bony pedicle, pedicle of vertebra, pedicles
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warning
Pericardial effusion
Extra fluid sitting in the thin sac that surrounds the heart. A small amount is often harmless and very common. A larger volume can press on the heart and stop it filling properly, which is why the size on the report — and how quickly it built up — matters more than the finding itself.
Also: cardiac effusion, fluid around the heart, fluid in heart sac
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warning
Periosteal reaction
New bone laid down by the thin outer wrapping of a bone when that bone is irritated by injury, infection, or another process. It shows up as a fine line or layer along the bone surface on x-ray, and its pattern helps the radiologist judge how concerning it is.
Also: bone surface reaction, periosteal bone reaction, periosteal change
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Periventricular
A descriptive term meaning "around the fluid-filled spaces in the middle of the brain." It points to the region of brain tissue that lies just next to the ventricles, where a finding has been seen. The word itself only marks the location — what matters is what is found there.
Also: around the brain's fluid spaces, around the ventricles, next to the ventricles
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Phalanx
This is simply the medical word for a finger or toe bone. Each finger has three of these small bones and the thumb and big toe have two, stacked end to end. Reports use the term to point precisely to which finger or toe segment a finding sits in.
Also: digit bone, finger bone, finger bones
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Pituitary gland
A pea-sized gland at the base of the brain that controls many of the body's hormones. It sits in a small bony pocket behind the eyes and directs other glands — the thyroid, adrenals, and reproductive organs. Radiologists name it when describing its size, shape, or any spot within it.
Also: brain hormone gland, hypophysis, master gland
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Plantar fascia
A thick band of fibrous tissue along the sole of the foot, running from the heel to the base of the toes. It supports the arch and acts like a spring while you walk. Reports mention it when describing thickening or inflammation, often called plantar fasciitis, best seen on MRI or ultrasound.
Also: arch tendon, foot arch band, plantar aponeurosis
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warning
Pleural effusion
A build-up of fluid in the thin space between the lungs and the chest wall. Small amounts often cause no symptoms; larger collections can press on the lung and make breathing harder. The cause matters more than the fluid itself — infection, heart strain, and inflammation are the usual culprits.
Also: fluid around lung, fluid around the lungs, fluid in the chest
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urgent
Pneumoperitoneum (free air)
Air sitting inside the belly cavity where there should be none. Normally air stays inside the stomach and intestines; finding it loose in the surrounding space usually means a hole somewhere in the gut wall has let it escape. It is almost always treated urgently because the underlying leak needs prompt attention.
Also: free abdominal air, free air, free air in the belly
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urgent
Pneumothorax
Air that has leaked into the space between the lung and the inside of the chest wall, where there should be no air at all. The trapped air presses on the lung and stops it from inflating fully. Small leaks sometimes heal on their own, but larger ones need urgent treatment because they can make breathing difficult quickly.
Also: PTX, air around the lung, air leak in chest
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Portable radiograph
An x-ray taken at the bedside with a wheeled machine, used when a patient is too unwell or immobile to travel to the x-ray department. The image is genuinely useful but a little less crisp than a film taken in the department, so reports often note this gently.
Also: bedside radiograph, bedside x-ray, mobile radiograph
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Projection views (AP, PA, lateral, oblique)
The named directions an x-ray beam travels through the body to make a picture. AP is front to back, PA is back to front, lateral is side on, and oblique is at an angle. Taking more than one direction lets the radiologist see a part from several sides.
Also: AP view, PA view, imaging projection
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Psoas muscle
A long, deep muscle on each side of the lower spine that runs down into the top of the thigh. It is a main hip flexor, lifting your knee toward your chest when you walk or climb stairs. Reports often name it as a landmark in the lower belly or to confirm it looks symmetric and normal.
Also: hip flexor, iliopsoas, psoas
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Pubis
This is the front part of your pelvis, the bone you can feel low down at the front, below the belly and above the groin. The left and right halves meet in the middle at a small joint. Reports name it to point to the front of the pelvic ring when describing a finding.
Also: front pelvic bone, os pubis, pubic bone
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Pulmonary
Anything to do with the lungs. It is simply the medical adjective for 'relating to the lungs', from the Latin word for lung. On its own it carries no good or bad meaning — it just tells you which organ a finding involves. The noun attached to it, like nodule or artery, is what actually matters.
Also: lung, lung-related, of the lungs
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warning
Pulmonary edema
Extra fluid leaking into the tiny air sacs and surrounding tissue of the lungs, making them heavy and less efficient at moving oxygen into the blood. It most often reflects strain on the left side of the heart, but inflammation, infection, kidney issues, and high altitudes can also cause it. Treatment focuses on the underlying reason.
Also: cardiogenic lung fluid, fluid in the lungs, lung congestion
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urgent
Pulmonary embolism
A blood clot that has travelled through the veins and lodged in one of the arteries supplying the lungs. Most start as a clot in a deep leg vein, break off, and ride the blood up through the heart before getting stuck. The size and location decide how serious it is, and the care team treats it promptly.
Also: PE, blood clot in the lung, clot in the lungs
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Pulmonary nodule
A small, rounded spot in the lung that stands out from the surrounding tissue. Most are smaller than a grape and most turn out to be harmless — leftover scars from old infections, tiny benign growths, or specks of inflammation. Size, shape, and whether it changes over time decide how closely it is watched.
Also: SPN, incidental lung nodule, lung nodule
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Pulmonary vasculature
The network of blood vessels inside the lungs that carries blood to pick up oxygen and return it to the heart. On a scan it forms the branching shadows fanning out from the centre. Reports describe whether these vessels look normal, fuller than usual, or sparse, since their fullness reflects pressure and flow.
Also: lung blood vessels, lung vasculature, pulmonary circulation
R
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Radiograph
The proper name for a plain x-ray picture — a single flat image made by passing a brief, low dose of x-rays through the body onto a detector. Dense things like bone show up white, air shows up black, and soft tissues sit in shades of grey in between.
Also: plain film, plain radiograph, plain x-ray
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Radius (forearm bone)
This is one of the two bones in your forearm, the one on the thumb side that runs from the elbow to the wrist. It does most of the work at the wrist and rotates your hand palm-up and palm-down. Reports name it to point to that forearm bone when describing a finding.
Also: forearm bone, radial bone, radius
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Rectum
The final straight section of the large bowel, sitting low in the pelvis just before the anus. It holds stool until you are ready to go, then signals the urge to pass it. Reports often name it to locate a finding in the lowest part of the bowel or to confirm it looks normal.
Also: back passage, final bowel section, lower bowel end
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Renal
Anything to do with the kidneys. It is simply the medical adjective for 'relating to the kidney', from the Latin word for kidney. On its own it carries no good or bad meaning — it just tells you which organ a finding involves. The noun attached to it, like cyst or stone, is what actually matters.
Also: kidney, kidney-related, of the kidney
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normal
Renal cyst
A small, fluid-filled sac inside the kidney. Most are harmless, develop quietly with age, and are picked up by chance on a scan done for something else. The radiologist's job is to tell the simple, benign kind apart from the rare more complex variety that needs a closer look — and most of the time it is the simple kind.
Also: benign kidney cyst, cyst on the kidney, fluid-filled kidney lesion
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Rotator cuff
A group of four small muscles and their tendons that wrap over the top of the shoulder and keep the upper arm bone seated in its shallow socket. Together they let you lift, turn, and steady the arm. Reports mention it when describing wear, inflammation, or tears in one of its tendons.
Also: cuff muscles, cuff tendons, rotator cuff tendons
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warning
Rotator cuff tear
Damage to one of the four small muscle-tendons that wrap around the top of the shoulder and keep the arm bone seated in its socket. The tear can be a thin partial fray on the surface or a full break through the tendon. Many are gradual age-related wear; others follow a sudden injury.
Also: cuff tear, partial-thickness cuff tear, rotator cuff injury
S
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Sacroiliac joint
The paired joints that connect the lower spine (sacrum) to the back of the pelvis (iliac bones), one on each side. They sit deep in the lower back, transfer weight between the spine and the legs, and move very little. They are common to mention on scans and are a frequent source of low back and buttock pain.
Also: SI joint, SI joints, SIJ
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Sacrum
The base of the tailbone — the large, triangular bone at the bottom of the spine, wedged between the two hip bones. It is made of fused vertebrae and forms the back wall of the pelvis. On a report it is usually just naming where at the bottom of the spine or back of the pelvis a finding sits.
Also: base of the spine, lower spine bone, sacral bone
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Scapula
The shoulder blade — the flat, triangular bone on each side of your upper back. It connects the arm to the collarbone and forms the socket of the shoulder joint. Many muscles attach to it, letting your shoulder move freely. On a report it is usually just naming where in the upper back or shoulder a finding sits.
Also: scapulae, shoulder blade, shoulderblade
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Sclerosis
An area where bone has become thicker and denser than usual, showing up as a whiter patch on an x-ray or CT. It is often the body's way of reinforcing bone under stress or healing, and most cases are old, stable, and harmless rather than a sign of disease.
Also: bone hardening, bone sclerosis, dense bone
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Sella turcica
A small saddle-shaped hollow in the bone at the base of the skull that cradles the pituitary gland. Its Latin name means 'Turkish saddle' because of its shape. Radiologists mention it when describing the pituitary gland sitting inside it, or when commenting on the size and shape of the bony pocket itself.
Also: Turkish saddle, hypophyseal fossa, pituitary fossa
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Sigmoid colon
The S-shaped final loop of the large bowel in the lower left side of the belly, just before the rectum. It stores formed stool until it is ready to pass. Its name comes from the Greek letter sigma because of its curve. Reports often name it to locate a finding in this part of the colon.
Also: S-shaped colon, pelvic colon, sigmoid
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warning
Soft tissue mass
A lump in the soft parts of the body — muscle, fat, fibrous tissue, nerves, or vessels — rather than in bone. It is a description of what was seen, not a diagnosis. Most are benign (lipomas, cysts, fibrous lumps); some are inflammatory; a smaller number turn out to be tumours that warrant further imaging or biopsy.
Also: fatty lump, muscle mass, non-bony mass
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Soft tissue swelling
Puffiness or thickening of the non-bony tissues — skin, muscle, fat, and the layers around a joint — seen as fullness around an area on a scan. It is the body's normal response to injury, inflammation, or infection, and very often settles as the underlying cause heals.
Also: puffiness, soft tissue edema, soft tissue oedema
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warning
Spinal canal stenosis
A narrowing of the bony tunnel that houses the spinal cord and nerve roots. The narrowing crowds the structures running through it, which can cause back pain, leg pain, numbness, or weakness depending on the level. Most cases develop slowly with age; the severity on imaging often correlates loosely with symptoms.
Also: central canal narrowing, central canal stenosis, cervical stenosis
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Spinal cord
The thick bundle of nerves that runs from the base of the brain down through the protective spine, carrying messages between the brain and the rest of the body. It controls movement and sensation in your limbs and trunk. Reports often name it to confirm it looks normal or to locate a finding nearby.
Also: cord, medulla spinalis, neural cord
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Spinous process
The bony bump that sticks out backward from each vertebra, forming the knobbly ridge you can feel down the middle of your back. Muscles and ligaments attach to it to support and move the spine. Reports often name it to locate a finding or to confirm the bone looks normal after a knock.
Also: back bump, bony spine of vertebra, spine bump
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Splenic
Anything to do with the spleen. It is simply the medical adjective for 'relating to the spleen', the fist-sized organ in the upper left belly. On its own it carries no good or bad meaning — it just tells you which organ a finding involves. The noun attached to it, like cyst or vein, is what actually matters.
Also: of the spleen, pertaining to the spleen, relating to the spleen
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warning
Splenomegaly
An enlarged spleen — the small, fist-sized organ tucked under the ribs on the left side. It is a sign, not a diagnosis: the spleen grows in response to many different things, from a recent viral infection to long-standing liver disease or a blood disorder. The reason behind the enlargement is what matters.
Also: big spleen, enlarged spleen, spleen enlargement
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warning
Spondylolisthesis
One of the bones in the spine has shifted forward, backward, or sideways relative to the bone below it, so the stack no longer lines up perfectly. The slip is often small and stable, but a larger shift can narrow the spinal canal or pinch a nerve, causing back pain or symptoms down a leg.
Also: anterolisthesis, degenerative spondylolisthesis, isthmic spondylolisthesis
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normal
Spondylosis
A general term for the slow, age-related wear of the spine — drying cushions, small bony spurs, and stiffer joints. It is the back's version of grey hair: nearly universal after middle age, often visible on scans of people who feel completely fine, and usually a description of normal ageing rather than a disease.
Also: arthritis of the spine, cervical spondylosis, degenerative disc disease
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Sternum
The breastbone — the flat, narrow bone running down the centre of your chest, the one you can feel in the middle of your ribcage. The ribs and collarbones attach to it, and it shields the heart and major vessels behind it. On a report it is usually just naming where in the front of the chest a finding sits.
Also: breast bone, breastbone, chest bone
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Study
In radiology, a single complete imaging examination of one patient on one day — for example, one MRI of the brain or one CT of the abdomen. A single examination is usually made up of several image sets, called series, captured from different angles or with different settings.
Also: DICOM study, current study, examination
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urgent
Subarachnoid hemorrhage
Bleeding into the thin, fluid-filled space that wraps around the brain, between two of its protective layers. It is a time-sensitive finding because the blood sits in the same space as the cerebrospinal fluid and can quickly affect the whole brain. The cause and the amount of bleeding decide how it is treated.
Also: SAH, aneurysmal bleed, bleed under the arachnoid
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Subluxation
A partial slipping of a joint, where the two bones have lost some of their normal alignment but are still partly in contact. It sits between a normal joint and a full dislocation, and depending on the joint and cause it can range from minor to something needing prompt care.
Also: joint malalignment, joint slipping, partial dislocation
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Subscapularis
The largest rotator cuff muscle, sitting on the front of the shoulder blade between it and the rib cage. It turns the arm inward and helps hold the ball of the arm bone in its socket. Reports mention it when describing wear, inflammation, or a tear in its tendon.
Also: rotator cuff muscle, shoulder muscle, subscapularis muscle
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Sulci
The grooves on the outer surface of the brain, between the raised folds. They are a normal part of how the brain is built — the wrinkled surface packs a much larger sheet of tissue into the limited space of the skull. Radiologists describe how deep or wide these grooves look as part of every brain scan.
Also: brain folds, brain grooves, cerebral sulci
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Superior vena cava
The large vein that drains oxygen-poor blood from the head, neck, arms, and upper chest back to the heart. Often shortened to SVC. It runs down the right side of the upper chest into the heart. Radiologists mention it when describing the vessels of the upper chest.
Also: SVC, great upper vein, main upper body vein
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Supraspinatus
The top muscle of the rotator cuff, running across the top of the shoulder blade and over the ball of the arm bone. It starts the movement of lifting the arm out to the side. Reports mention it often because its tendon is the most common spot for shoulder wear and tears.
Also: rotator cuff muscle, shoulder muscle, supraspinatus muscle
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Suspicious
A hedging word radiologists use when a finding has some features that raise concern but the scan alone cannot prove a diagnosis. It usually triggers more workup — a follow-up scan, biopsy, or specialist referral — rather than a definite answer. The word is a flag, not a verdict.
Also: concerning, concerning for, raises concern for
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Tarsal bones
These are the seven bones at the back and middle of your foot, between the ankle and the long foot bones. They include the heel bone and the bones that form the arch. Reports name them to point to the ankle and midfoot region, or to one specific bone, when describing a finding.
Also: ankle bones, hindfoot bones, midfoot bones
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Tendinopathy
A catch-all term for a tendon that's been irritated, overloaded, or worn down over time. The tissue thickens, loses some of its tidy fibre pattern, and may show small areas of damage inside it. Common in shoulders, elbows, knees, and ankles, and often linked to repeated load rather than a single injury.
Also: tendinitis, tendinosis, tendon degeneration
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Tendon
A tough, rope-like band of tissue that connects a muscle to a bone, transmitting the muscle's pull so the joint can move. Tendons are found throughout the body. Reports mention them when describing wear, inflammation, or a tear, all of which are best seen on MRI.
Also: fibrous cord, muscle tendon, sinew
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Thickening
A description that a wall, lining, or layer of tissue measures more than expected for that area. The word is purely a measurement — it does not say whether the cause is inflammation, infection, scarring, a benign change, or something more serious. The rest of the report and the clinical picture decide what it means.
Also: circumferential thickening, focal thickening, mural thickening
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Tibia
The shinbone — the large, strong bone at the front of your lower leg, the one you feel just under the skin along your shin. It carries most of your body weight between the knee and the ankle. On a report it is usually just naming where in the lower leg a finding sits. The word itself is plain anatomy.
Also: lower leg bone, shin, shin bone
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Trachea
The main airway, often called the windpipe, that carries air from the throat down into the chest before splitting toward each lung. It runs down the centre of the neck and upper chest. Reports check that it sits in the midline and is a normal width, since both can shift when something nearby presses on it.
Also: air pipe, breathing tube, main airway
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Ulna
This is one of the two bones in your forearm, the one on the little-finger side that runs from the elbow to the wrist. It forms the bony point of the elbow and the small bump on the pinky side of the wrist. Reports name it to point to that forearm bone when describing a finding.
Also: elbow-side forearm bone, forearm bone, inner forearm bone
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Ultrasound
An imaging test that uses high-frequency sound waves rather than X-rays to look inside the body. A handheld probe sends sound pulses through the skin and listens for the echoes, building a live picture on a screen. It involves no radiation, is widely available, and is especially good at looking at soft, fluid-filled, and moving structures.
Also: US, doppler scan, echo
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Unremarkable
A reassuring word in radiology. It means the radiologist looked carefully at a structure and found nothing worth pointing out — no swelling, no abnormal spots, no concerning changes. Despite how it sounds in everyday English, on a scan report this is good news.
Also: grossly normal, negative study, no abnormality detected
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Ureter
A thin muscular tube, one on each side, that carries urine from a kidney down to the bladder. Gentle squeezing waves push the urine along. There are two, one per kidney. Reports often name the ureters to confirm they look normal or to locate a finding such as a stone along their path.
Also: kidney tube, renal drainage tube, ureteric tube
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Ventricles (brain)
The four connected, fluid-filled chambers in the centre of the brain. They make and circulate the clear cushioning fluid that bathes the brain and spinal cord. Their size and shape are routinely measured on scans because changes in either can hint at swelling, blockage, or natural shrinkage of the surrounding tissue.
Also: CSF spaces, brain fluid chambers, cerebral ventricles
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Vertebra
A single backbone — one of the small, stacked bones that build the spine. You have around 33 of them running from the base of the skull to the tailbone. On a report it is simply naming a level of the spine, the way a street number names a spot along a road. The word itself is just anatomy.
Also: back bone, backbone bone, spinal bone
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Vertebral body
The solid, weight-bearing front block of each backbone. It is the chunky, cylinder-shaped part of a vertebra that stacks up to carry your body's load, with cushioning discs sitting between each one. On a report it is just naming which part of the spine bone a finding sits in. The term itself is plain anatomy.
Also: body of vertebra, front of the vertebra, spine bone block
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Vertebral endplate
The flat top and bottom surfaces of each spinal bone, where the bone meets the cushioning disc that sits between vertebrae. These thin caps of bone and cartilage anchor the disc in place and let nutrients pass into it. Reports often name them when describing wear, height, or changes next to a disc.
Also: bony endplate, disc endplate, endplates
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Weight-bearing view
An x-ray of a leg, foot, knee, or hip taken while you stand and put your normal load through the joint, rather than lying down. Standing makes the joint behave as it does in real life, so problems that only show up under load become visible.
Also: erect view, load-bearing view, standing view
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White matter
The deeper layer of the brain made up of the long fibres that carry signals between different regions. It is named for its pale appearance under the microscope, caused by the fatty coating around those fibres. Reports often mention changes here in the context of ageing, small blood vessel wear, or specific neurological conditions.
Also: WMH, cerebral white matter, deep white matter
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