Free Wrist Radiograph Viewer for the Carpus and Scaphoid

The Five Wrist X-ray Views and What Each One Answers

A wrist series is rarely one film. Each projection answers a different question, and a report that cites “PA” or “scaphoid view” is telling you which question the technologist was trying to answer.

The posteroanterior view is shot with the shoulder abducted to ninety degrees and the elbow bent, which keeps the forearm in a reproducible position. That matters because ulnar variance — how far the ulna sits relative to the radius at the wrist — changes with forearm rotation, so a PA taken any other way can misstate it by a millimeter or more, enough to flip a diagnosis of ulnar impaction.

The lateral view is where carpal alignment lives. It is the projection used to draw the scapholunate angle and the capitolunate angle, the two numbers that separate a normal carpus from one with a rotary subluxation of the scaphoid or a midcarpal instability pattern.

An oblique view, angled roughly forty-five degrees off the PA, opens up the scaphoid waist and the trapezium so a nondisplaced fracture line or early thumb-base arthritis is not hidden behind overlapping carpal shadows.

A dedicated scaphoid series adds ulnar deviation of the wrist, which straightens the normally curved scaphoid and stretches it into profile — the single best plain-film position for catching a hairline waist fracture.

Finally, a clenched-fist stress view has you grip tightly while the film is taken. Gripping loads the wrist axially and, if the scapholunate ligament is torn, forces the scaphoid and lunate apart into a visible gap that a relaxed view would not show.

Why a Fresh Scaphoid Fracture Can Look Normal on Day One

A scaphoid waist fracture is notorious for being radiographically silent right after the fall. The fracture line can be a hairline gap with no displacement, and until local bone resorption widens that gap over one to two weeks, the plain film simply does not show it. That is why a clinician who suspects a scaphoid injury on exam — tenderness in the anatomical snuffbox — will often splint the wrist and repeat the X-ray ten to fourteen days later, or move straight to MRI or CT, rather than clear the wrist off a single negative film. Missing this fracture matters because the scaphoid's blood supply enters from its distal pole, so a waist fracture can starve the proximal fragment and lead to nonunion or avascular collapse if it goes untreated.

Reading Gilula's Arcs to Spot Carpal Malalignment

On a well-positioned PA view, the carpal bones should trace three smooth, continuous curves — Gilula's arcs — running along the proximal and distal borders of the proximal carpal row and the proximal border of the distal row. A step-off, an overlapping bone, or a break in one of those arcs is the fastest visual cue that a carpal bone has shifted out of position, whether from a perilunate dislocation, a lunate that has tipped out of its socket, or a scaphoid fracture that has let the proximal row collapse. It is a pattern worth learning to trace yourself before an AI pass, because the arcs are simple lines and a break in them is easy to miss at a glance if you are only scanning for an obvious fracture edge.

Wrist and Carpal Conditions Seen on Radiograph

How It Works

What This Tool Measures on a Single Wrist Film

Beyond windowing and zooming, this viewer lets you drop calibrated rulers directly on the rendered image: drag one across the radial and ulnar articular surfaces to read ulnar variance in millimeters, trace the scapholunate gap on a PA or stress view, or set an angle tool along the radial shaft and articular surface to read radial inclination. You can also invert the grayscale to push the cortical margin forward when you are chasing a subtle scaphoid line, and open a scaphoid PA view next to its ulnar-deviation companion in a side-by-side pane so a fracture that is faint on one projection is easier to confirm against the other.

AI Explanation vs a Radiology Second Opinion

An AI pass over the rendered image can walk you through report terminology and point out what the pixels show, but it is not a substitute for a radiologist's signed reading. Lean on it to prepare sharper questions for your clinician, particularly when a wrist report mentions a positive Terry Thomas sign, a ring sign, or dorsal tilt on a healed distal radius fracture.

Decoding Common Wrist Report Language

“Positive ulnar variance” means the ulna extends further toward the hand than the radius at the wrist joint, a pattern linked to ulnar impaction and TFCC wear over time; “negative variance” is associated with Kienböck disease, where the lunate loses its blood supply.

The “Terry Thomas sign” refers to a gap between the scaphoid and lunate wider than the normal two to three millimeters, named for the actor's gap-toothed smile, and it signals a torn scapholunate ligament.

A “ring sign” is the cortical outline of a scaphoid that has rotated end-on to the beam, a secondary clue to scapholunate instability rather than a separate structure.

“Dorsal tilt” describes the distal radius articular surface angling toward the back of the hand after a fracture heals in a less-than-ideal position, which can alter wrist mechanics; “scaphoid nonunion” means the fracture line never bridged with new bone and the two fragments remain separate months out.

One Projection, No Slices to Scroll

A wrist radiograph flattens the carpus into a single two-dimensional projection per exposure, so there is no stack of slices to page through and no volume to spin around the way an MRI or CT lets you. Every bone in the beam's path overlaps in that one frame, which is exactly why a suspected scaphoid or carpal injury needs several angles rather than one — each additional view is the only way to recover the depth information a single film cannot capture.

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