How to Upload DICOM Files: Complete Guide

Tips for Best Results & Quick Start

Upload the complete folder: Don't select individual .dcm files. Upload the entire folder so all slices are available for 3D analysis.
Extract ZIP files first: If your scan came as a ZIP archive, extract it to a folder before uploading.
Keep folder structure intact: Don't reorganize or rename files. The original structure helps the system organize series correctly.
Upload each series separately: For multiple scan series (e.g., pre-contrast and post-contrast), analyze each series separately for best results.
Check file count: A typical CT scan has 10-500 .dcm files. If you only see a few files, you might be missing data.

Step-by-Step: Uploading DICOM Folders

1. Prepare Your DICOM Files

DICOM files typically come from medical imaging centers on a CD, DVD, USB drive, or as a downloaded folder. Your scan data will be in a folder containing multiple files with the .dcm extension.

Important: If your files are in a ZIP archive, extract them first before uploading.

2. Access the DICOM Uploader

Go to readyourlab.com
Click on "Understand Your CT or MRI Scan" or "Analyze My Scan"
You'll see the DICOM viewer interface with a folder upload button

3. Select Your DICOM Folder

Click the "Open CT or MR scan folder" button. You have two options:

Select the entire folder containing all your .dcm files
The folder may contain a DICOMDIR file. This is a special index file that helps organize the scan data

Tip: The browser will ask for folder access permission. This is normal and required to read all the .dcm files in your scan folder.

4. Select and Analyze Your Series

After uploading, you'll see your scan data organized by:

Patient - Your patient information
Study - A specific scan session (e.g., "CT Chest 2026-01-15")
Series - Individual image sequences within a study

Click on a purple series card to preview the images, then click "Analyze this Series with AI" to get your AI-powered radiology report.

5. Ask Follow-Up Questions

After receiving your AI-generated radiology report, you can ask follow-up questions to get a clearer picture of your scan results. Radiology reports can sometimes be confusing with technical terminology and medical jargon.

The AI remembers your scan context, so you can:

Clarify medical terms - "What does 'ground-glass opacity' mean?" or "Can you explain what 'nodule' means in simple terms?"
Understand findings - "Is this finding concerning?" or "What does this mean for my health?"
Get more context - "How common is this finding?" or "What could cause this?"
Ask about next steps - "What should I discuss with my doctor?" or "Do I need follow-up imaging?"
Compare findings - "How does this compare to my previous scan?" (if you've uploaded multiple scans)

Why This Matters: Radiology reports often contain complex medical terminology that can be difficult to understand. Follow-up questions help you get a complete, clear picture of your scan results, making it easier to discuss findings with your healthcare provider and make informed decisions about your care.

Example Questions: "Can you explain the difference between a benign and malignant nodule?", "What does 'no acute findings' mean?", "Should I be worried about this small nodule?", or "What questions should I ask my radiologist about this report?"

Understanding .dcm files

What is a .dcm File?

A .dcm file (DICOM file) is a medical imaging file format used to store medical images and their associated metadata. DICOM stands for Digital Imaging and Communications in Medicine.

Each .dcm file can contain:

A single CT slice - One 2D image from a CT scan series
Multiple CT slices, a complete 3D volume - Several 2D images stored in one file

Note: The number of slices per file varies by imaging center and scanner settings. Some systems create one .dcm file per slice, while others bundle multiple slices together.

What kind of metadata do .dcm files store?

Every DICOM file contains extensive metadata embedded within the file itself. This metadata provides crucial information about the scan and the patient.

Patient Information

Patient Name - Usually anonymized or partially anonymized
Patient ID - Unique identifier assigned by the medical facility
Date of Birth - Patient's birth date
Sex - Patient's biological sex

Study Information

Study Date & Time - When the scan was performed
Study Description - Type of scan (e.g., "CT Chest", "MRI Brain")
Study Instance UID - Unique identifier for the study
Referring Physician - Doctor who ordered the scan
Accession Number - Order number from the hospital/imaging center

Series Information

Series Description - Specific sequence name (e.g., "Axial 5mm", "Coronal Reformat")
Series Number - Order of the series within the study
Modality - Imaging type (CT, MR, XR, US, etc.)
Number of Images - How many slices are in this series

Image Acquisition Parameters

Slice Thickness - Thickness of each image slice (e.g., 1mm, 5mm)
Pixel Spacing - Physical size of each pixel in the image
Image Position - 3D coordinates of where the slice is located in the body
Image Orientation - How the image is oriented (axial, coronal, sagittal)
Window/Level - Display settings for optimal contrast
KVP & mAs - X-ray tube settings (for CT scans)
Contrast Agent - Whether contrast dye was used

Equipment Information

Manufacturer - Scanner manufacturer (Siemens, GE, Philips, etc.)
Model Name - Specific scanner model
Software Version - Scanner software version
Institution Name - Hospital or imaging center name

Why This Matters: All this metadata allows ReadYourLab's AI to understand the context of your scan, properly reconstruct 3D volumes, and provide accurate analysis. The metadata is automatically read when you upload your DICOM folder.

What is a DICOMDIR File?

Understanding DICOMDIR

A DICOMDIR file is a special index file that acts as a table of contents for your DICOM folder. It's an optional but helpful file that some imaging centers include with your scan data.

What DICOMDIR Contains:

A hierarchical index of all patients, studies, and series in the folder
Pointers to where each .dcm file is located
Summary information about each series (number of images, descriptions, etc.)

Benefits of Using DICOMDIR

Faster Loading - The system can quickly understand the folder structure without reading every .dcm file first
Better Organization - Helps group related series together correctly
Multiple Studies - If your folder contains scans from multiple dates or patients, DICOMDIR helps organize them

Good to Know: If your folder doesn't have a DICOMDIR file, that's perfectly fine! ReadYourLab can still read and organize your .dcm files by examining the metadata in each file. You can upload either the DICOMDIR file or the entire folder - both work.

How CT Slices Are Organized in .dcm Files

Understanding how CT slices are stored in DICOM files is important for getting the best analysis results.

Single Slice Per File (Most Common)

Most commonly, each .dcm file contains exactly one CT slice (one 2D image). A typical CT scan series might have:

50-500 individual .dcm files
Each file = one slice through the body
Together, they form a complete 3D volume

Example: A chest CT might have 200 .dcm files, each representing a 1mm-thick slice from the top of the chest to the bottom.

Multiple Slices Per File

Some imaging systems bundle multiple slices into a single .dcm file. In this case:

One .dcm file may contain 10, 50, or even 100+ slices
The file is larger but there are fewer total files
All slices in the file are part of the same series

Example: A brain CT might have 5 .dcm files, with each file containing 40 slices (5 files x 40 slices = 200 total slices).

Why This Matters for Analysis

ReadYourLab handles both formats automatically. When you upload your DICOM folder, our system:

Reads all .dcm files in your folder
Extracts each slice (whether from single-slice or multi-slice files)
Reconstructs the complete 3D volume using the slice position metadata
Organizes slices into series based on their metadata

This is why uploading the complete folder is important - the AI needs all slices to provide accurate 3D volumetric analysis, not just a single image.

Troubleshooting

Can't see folder upload option?

Make sure you're using a modern browser (Chrome, Firefox, Edge, or Safari). Older browsers may not support folder uploads.

Files not loading?

Verify that your files have the .dcm extension. Some systems might use different extensions, but .dcm is standard.

Series not appearing correctly?

This usually means the metadata in your .dcm files is incomplete or corrupted. Contact your imaging center for a new copy of your scan data.

How to Upload DICOM Files to ReadYourLab