Primary hyperparathyroidism: magnification film of the index finger showing early subperiosteal bone resorption.
This magnified film of the middle and distal phalanges of the index finger shows the early bony changes of hyperparathyroidism. Slight subperiosteal bone resorption is present along the radial aspect of the middle phalanx, the characteristic site for early change. There is also poor definition of the cortical outline of the tip of the distal phalanx, The technique of magnification radiography using a fine-focus X-ray tube is helpful in identifying these subtle appearances.
