Identifying the Medial Process of the First Metacarpal on Wrist PA X-ray

Standard Radiographic Views for Evaluation

A standard PA view of the wrist is essential for visualizing the first metacarpal and its medial process, as part of a complete radiographic examination that includes multiple views, according to the American College of Radiology 1
For comprehensive wrist evaluation, a 3-view examination is recommended, including posteroanterior (PA), lateral, and 45° semipronated oblique views, as suggested by the American College of Radiology 1
When specifically examining the thumb and first metacarpal, a 2-view radiographic examination is typically sufficient, though adding an oblique projection can slightly increase diagnostic yield, as noted by the American College of Radiology 1

High-quality PA radiographs require proper positioning with the palm flat against the detector, fingers extended, and thumb slightly abducted, as recommended by the American College of Radiology 1, 2
Inadequate positioning can lead to rotational artifacts that may obscure the medial process of the first metacarpal, according to the American College of Radiology 1
For optimal visualization of the first metacarpal and its articulation with the trapezium, the wrist should be in neutral position without ulnar or radial deviation, as suggested by the American College of Radiology 1, 3

When initial radiographs are equivocal but clinical suspicion remains high, CT without IV contrast is commonly used to confirm or exclude suspected wrist fractures, as recommended by the American College of Radiology 1, 3
For detailed evaluation of the first metacarpal's morphology, including the medial process, 3D reconstructions from CT can be particularly helpful, according to the American College of Radiology 3

Inadequate number of views: A single PA view is insufficient for complete evaluation; multiple projections are necessary, as noted by the American College of Radiology 1
Poor positioning: Rotation of the wrist can significantly alter the appearance of the first metacarpal and its medial process, according to the American College of Radiology 1
Failure to correlate with clinical findings: Radiographic appearance should always be interpreted in the context of the patient's symptoms and physical examination, as suggested by the American College of Radiology 3