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.
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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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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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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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urgent
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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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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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 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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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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