Free Knee MRI Viewer Built for the Meniscus and Cruciates
Load a knee MRI exam straight into your browser and page through every sagittal, coronal, and axial slice the scanner captured, from the tibial plateau up to the quadriceps tendon. Once you have found the slices your report mentions, an optional AI pass can translate the signal you are looking at into plain language. Nothing leaves your computer until you choose to send rendered frames for that review.
Opens on this device. Nothing is uploaded.
Reading Between the Bones: What Knee MRI Adds to a Plain X-Ray
A knee X-ray shows the femur, tibia, and patella but stays blind to the soft tissue holding the joint together. MRI fills that gap by imaging the menisci, the anterior and posterior cruciate ligaments, the medial and lateral collaterals, the retinacula around the kneecap, the articular cartilage lining every joint surface, and the marrow inside the bone itself. Fluid-sensitive sequences make torn fibers, bruised bone, and inflamed synovium glow brighter than the tissue around them, which is exactly the contrast a radiologist relies on to locate and stage an injury.
What Is Actually Inside a Knee MRI Series
A typical knee exam is not one image but several separate series, each acquired in a different plane and with a different pulse sequence, and the viewer keeps them as distinct stacks you can flip between. The sagittal proton-density fat-saturated series is usually the workhorse for the menisci and the cruciate ligaments, because suppressing fat signal makes a meniscal tear or an ACL sprain stand out as a bright line against otherwise dark fibrocartilage and ligament tissue.
The coronal plane is where the medial and lateral collateral ligaments run nearly their full length in a single slice, and it is also the best plane for judging meniscal root attachments near the tibial spines. The axial series cuts across the joint instead of along it, which is what lets you evaluate the patellofemoral joint, the medial and lateral retinacula, and patellar tracking without the kneecap overlapping the femur the way it does on a sagittal view.
T2-weighted and STIR sequences are the ones to open first when a report mentions bone marrow edema, because both null out normal fat signal and let fluid inside the trabecular bone light up, marking a bone bruise or an occult fracture. T1-weighted images run in the opposite direction: fat stays bright and fluid stays dark, which is why T1 is the plane radiologists reach for when they are checking marrow fat content or following up a graft after ACL reconstruction, where graft signal and tunnel position matter more than fluid contrast.
Findings a Knee Radiologist Watches For
- Discontinuous or absent ACL/PCL fibers, and the associated bone-bruise pattern that follows a pivot-shift injury
- Meniscal tear geometry — bucket-handle, radial, horizontal cleavage, or root tear — and whether the tear sits in a blood-supplied zone that can heal
- Focal or diffuse articular cartilage loss, including patellar chondromalacia graded by depth
- Subchondral bone marrow edema and stress-response bone bruising
- A joint effusion or a popliteal (Baker's) cyst tracking behind the knee
- Grade 1 through 3 sprains of the medial or lateral collateral ligament, and patellar maltracking on axial slices
Knee Conditions on MRI
How It Works
Upload DICOM Files
Drop your MRI ZIP file or individual .dcm files. Supports all standard DICOM transfer syntaxes including JPEG Lossless.
View in Browser
Navigate through slices with keyboard arrows or the slider. Adjust windowing, zoom, pan, and measure distances.
Get AI Analysis
4 AI models (GPT, Gemini, Claude, Grok) analyze independently. Claude synthesizes a unified report with findings and confidence levels.
Working With a Knee Stack Once It Is Loaded
Past the initial upload, the viewer behaves like a lightweight PACS workstation scoped to your own knee study. Scroll one slice at a time through each series to follow a meniscal tear from its anterior horn to its posterior root, or jump straight to the slice number your report cites. Window and level controls let you retune brightness and contrast on the fly, which matters on a knee study because bone, cartilage, and fluid sit close together in signal intensity and a preset built for another joint can wash out the detail you actually need. Distance measurement in millimeters lets you check cartilage thickness or effusion depth against the values a report quotes, and opening two series side by side — say the sagittal PD-fat-sat next to the coronal T2 — makes it far easier to confirm that a finding on one plane lines up with the same structure on the other.
3D and Multiplanar Reconstruction for the Knee Joint
Multiplanar reconstruction rebuilds sagittal, coronal, and axial views from a single acquired volume instead of relying on three separately scanned series. Your knee study can be reformatted this way in the browser once the source series has enough slices and consistent spacing for the math to hold up, all computed from DICOM data parsed locally on your device.
Whether a knee volume reconstructs cleanly into a rotatable 3D view depends on how it was acquired, your device's graphics capability, and how thin and evenly spaced the slices are. AI support built on top of that view remains a tool for preparing clinician conversations, never a stand-in for a radiologist's read.
Compare MPR, 3D DICOM viewing, and volume renderingLocating the Structure Your Knee Report Names
A knee report rarely gives you a slice number, so finding the exact structure it describes usually starts with the plane the finding is easiest to see on. A posterior horn meniscal tear is fastest to locate on the mid-sagittal images where the meniscus looks like a solid dark bowtie; scroll until the bowtie appears, then step slice by slice toward the joint line looking for a bright cleft cutting through it. An ACL or PCL mention sends you back to the same sagittal series but further toward the intercondylar notch, where an intact ligament runs as one continuous dark band from femur to tibia. Collateral ligament findings are quickest on coronal slices near the joint margins, and anything involving the kneecap — chondromalacia, maltracking, a retinacular tear — belongs on the axial series where the patella and trochlear groove sit side by side in the same frame.
Why Two Knee MRI Exams Can Look Nothing Alike
Not every knee scan is captured the same way, and the difference shows up the moment you start scrolling. A conventional exam built from 3 to 4 millimeter slices with a small gap between them trades some spatial detail for scan speed, so a small root tear or a thin cartilage fissure can fall partly inside the gap and look softer than it actually is. A thin, isotropic 3D cartilage sequence acquires near-cubic voxels with no gap at all, which is why it can be reformatted into any plane after the fact without the blur a gapped stack would produce, at the cost of a longer scan and images that read a little differently than the fat-saturated sequences most reports are written against.
Why Use Our Free MRI Viewer
Browser-Based Viewing
Raw MRI files stay on your device for DICOM parsing, rendering, and viewing. If you request AI analysis, the app uses rendered images and minimal context.
No Installation Required
Works in any modern browser — Chrome, Firefox, Safari, Edge. No plugins, no Java, no desktop software to download.
AI-Powered Analysis
Four independent AI models can explain rendered MRI images. Each model provides its own findings, then Claude synthesizes a consensus report.
Advanced Viewing Tools
Multi-plane navigation, windowing presets (bone, soft tissue, brain), zoom up to 4x, pan, and distance measurement in millimeters.
All MRI Sequences Supported
T1, T2, PD, STIR, FLAIR, gradient echo, and fat-suppressed sequences. Sagittal, coronal, and axial planes.
Downloadable PDF Report
Download an educational AI summary with structured observations, suggested severity grades, and areas of model agreement to discuss with your doctor.
Supported MRI Formats
DICOM (.dcm) — individual slice files
ZIP archives — containing DICOM series folders
JPEG Lossless (1.2.840.10008.1.2.4.70) transfer syntax
Explicit VR Little Endian, Implicit VR Little Endian
8-bit, 12-bit, and 16-bit pixel depth
MONOCHROME1 and MONOCHROME2 photometric interpretation
Frequently Asked Questions
Does viewing a knee MRI here cost anything?
No. Loading, scrolling, windowing, and measuring on a knee study is free with no cap on how many exams you open. A credit is only spent when you ask the AI models to review rendered frames from the study, and each analysis session costs $10.
Where do my knee DICOM files actually go?
Nowhere. The DICOM parsing and slice rendering for your knee study run in your browser through JavaScript and WebAssembly, so the raw files never leave your device. If you request AI analysis, only the rendered images and minimal supporting context are sent for that one review.
Which knee sequence should I check first for a meniscus tear?
Start with the sagittal proton-density fat-saturated series — it is where meniscal fibers contrast most cleanly against suppressed fat. Coronal T2 confirms root and collateral findings, and the viewer loads whatever sequences your exam includes without requiring a particular one.
Will a knee study from my clinic's scanner actually open?
Almost certainly. The DICOM parser reads output from Siemens, GE, Philips, Canon, and Hitachi scanners at both 1.5T and 3T, along with the transfer syntaxes those vendors commonly export, so a typical knee study ZIP from an imaging center opens without conversion.
Can the viewer tell me if my ACL is torn?
The viewer itself only displays your images — it does not interpret them. The optional AI layer can describe what it observes in the rendered sagittal and coronal frames around the intercondylar notch, but that description is informational and does not replace a radiologist confirming an ACL tear.
How does the four-model AI review handle a knee study?
Four independent models each examine the rendered knee images and report findings with their own confidence level, then Claude synthesizes those into one summary that notes where the models agree on the menisci, ligaments, cartilage, or marrow, and where they diverge.
My knee report mentions a bone bruise — where do I look for it?
Switch to a T2 or STIR series and scroll toward the femoral condyle or tibial plateau the report names. A bone bruise shows as a poorly defined bright patch inside the otherwise darker marrow, usually paired with an ACL or meniscal finding from the same injury.
Not sure your export will open? Check the full supported file format list before you upload.
Knee Imaging Focus
On Analyze My Knee, the viewer helps you review knee scans before discussing them with a clinician. It is built for educational inspection, not self-diagnosis.
Common knee findings
Review meniscus tears, ACL injury patterns, bone bruises, collateral ligament injury, bursitis, cartilage loss, and patellar tracking findings with privacy-first browser viewing.
Start with knee guides
Use the linked knee pages to understand report language and the imaging signs your clinician may mention.