Free Wrist CT Viewer for Scaphoid Fractures and Carpal Alignment

Getting From Disc To Report

Why A Wrist CT Follows A Negative X-Ray

A scaphoid fracture is the classic reason a wrist CT gets ordered at all. Roughly a quarter of true scaphoid fractures do not show on the initial X-ray because the fracture line runs through overlapping carpal bone at an angle plain films cannot catch. When snuffbox tenderness persists after a fall onto an outstretched hand and the X-ray reads clean, CT along the long axis of the scaphoid is what actually finds the occult waist fracture, or confirms there is nothing there and the wrist can come out of the cast early.

CT is also the study that settles whether a known scaphoid fracture has gone on to nonunion, because it shows the fracture line, any sclerosis at the margins, and cyst formation far more reliably than a repeat X-ray. For a distal radius fracture, CT measures articular step-off and gap in millimeters, the number that decides whether a surgeon reduces the joint surface with plates and screws or lets it heal in a cast. After volar plate fixation, CT checks that no screw has penetrated the dorsal cortex, a detail that is easy to miss on a lateral X-ray but obvious on an axial CT slice. A hook of hamate fracture, easy to miss entirely on standard wrist views, usually needs a dedicated carpal tunnel view or CT before it is ever seen.

What A Wrist CT Dataset Actually Contains

A modern wrist CT is acquired as a helical volume of sub-millimeter axial slices, then reconstructed twice from that same raw data: once on a sharp bone kernel that makes cortical margins and fracture lines crisp, and once on a smoother soft-tissue kernel that reduces the edge noise the bone kernel introduces around the flexor and extensor tendons. Because the acquired voxels are isotropic, the scanner or the viewer can build a reformat angled along the scaphoid’s own long axis, the orientation a hand surgeon actually reads, without losing any detail from the original axial pass.

What The Viewer Puts In Your Hands

Making Sense Of The Report Wording

Wrist CT reports lean on a handful of recurring phrases. “Articular step-off” is reported in millimeters and describes how far one fragment of the radius joint surface sits above or below its neighbor; a couple of millimeters is often the threshold surgeons use to decide on fixation. “Scapholunate widening” refers to a gap opening between the scaphoid and lunate bones, a sign of ligament injury that can progress toward scapholunate advanced collapse if it goes untreated. “DISI” and “VISI” describe the lunate tipping dorsally or volarly relative to its neighbors, visible on a sagittal reformat. “Nonunion” at the scaphoid waist means the fracture line is still visible with sclerotic or cystic margins well past the expected healing window, and post-operative studies add hardware-position language, noting whether a screw sits centrally within the scaphoid or has backed out toward either pole.

Where CT Stops And MRI Takes Over

Reading cortical bone at the scaphoid waist — fracture lines, fragment position, hardware, and whether healing has actually progressed — is where CT does its best work. Ask the same slice about the triangular fibrocartilage complex, the scapholunate and lunotriquetral ligaments, or early bone bruising, and it comes up short; those need MRI's contrast-weighted sequences or a dedicated arthrogram to show clearly. An acute scapholunate ligament tear or a triangular fibrocartilage tear can look entirely unremarkable on CT even in a joint that is genuinely unstable. So an occult scaphoid fracture gets its bone question answered on CT, while a purely ligamentous wrist injury with normal-looking bone usually heads straight to MRI instead.

Supported Wrist CT Formats

Frequently Asked Questions

3D Rendering For Scaphoid And Carpal Review

A carpal series is almost always a genuine volumetric acquisition, so it reformats into thin reformats and 3D without any real loss of detail. Fragment displacement at the scaphoid waist, a step-off at the radius, or hardware trajectory after plating is simply easier to point out on a spinning 3D wrist than to describe slice by slice — how crisp it looks still traces back to the slice thickness, spacing, and kernel the scanner used going in.

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