Figure 7f.

Fourth-degree frostbite of the hands in a 55-year-old man. (a) Dorsal photographs show gangrene involving all digits of both hands. (b–d) Multiphase ^99mTc-MDP bone scintigraphic images of the hands show absent tracer uptake throughout the bilateral phalanges in the palmar blood flow phase at 80 seconds (with markers delineating the distal aspects of the fingers) (b), palmar soft-tissue phase (without markers) (c), and 4-hour delayed phase (with markers) (d). Note the increased tracer uptake at the metacarpophalangeal joints proximal to the level of necrosis on the delayed phase image. (e, f) Fused SPECT/CT images of the right (e) and left (f) hands show absent tracer uptake distal to the metacarpophalangeal joints bilaterally, with the exception of increased uptake in the left second and third proximal phalanges. SPECT/CT enables delineation of the precise level of tracer cutoff. The patient ultimately underwent amputation of the bilateral thumbs at the level of the mid proximal phalanges and total amputation of the other fingers.