Frostbite: Spectrum of Imaging Findings and Guidelines for Management

Abstract

Frostbite is a localized cold thermal injury that results from tissue freezing. Frostbite injuries can have a substantial effect on long-term limb function and mobility if not promptly evaluated and treated. Imaging plays a critical role in initial evaluation of frostbite injuries and in monitoring response to treatment. A multimodality approach involving radiography, digital subtraction angiography (DSA), and/or multiphase bone scintigraphy with hybrid single photon emission computed tomography (SPECT)/computed tomography (CT) is often necessary for optimal guidance of frostbite care. Radiographs serve as an initial survey of the affected limb and may demonstrate characteristic findings, depending on the time course and severity of injury. DSA is used to evaluate perfusion of affected soft tissues and identify potential targets for therapeutic intervention. Angiography-directed thrombolysis plays an essential role in tissue preservation and salvage in deep frostbite injuries. Multiphase bone scintigraphy with technetium 99m-labeled diphosphonate provides valuable information regarding the status of tissue viability after initial treatment. The addition of SPECT/CT to multiphase bone scintigraphy enables precise anatomic localization of the level and depth of tissue necrosis before its appearance at physical examination and can help uncover subtle findings that may remain occult at scintigraphy alone. Multiphase bone scintigraphy with SPECT/CT is the modality of choice for prognostication and planning of definitive surgical care of affected limbs. Appropriate use of imaging to direct frostbite care can help limit the effects that these injuries have on limb function and mobility. ©RSNA, 2016.

Figures

Figure 1a.

Right toe frostbite in a 55-year-old man. (a) Initial dorsoplantar radiograph shows soft-tissue irregularities of the first, second, and fifth toes without underlying bone changes. (b) Dorsoplantar radiograph obtained 4 months later at follow-up shows progression of the first and second toe soft-tissue defects and a new periarticular erosion of the distal first proximal phalanx (black arrowhead). Note the interval healing of the soft tissue of the fifth toe, with new subtle osteopenia of the fifth distal phalanx (white arrowhead).

Figure 1b.

Right toe frostbite in a 55-year-old man. (a) Initial dorsoplantar radiograph shows soft-tissue irregularities of the first, second, and fifth toes without underlying bone changes. (b) Dorsoplantar radiograph obtained 4 months later at follow-up shows progression of the first and second toe soft-tissue defects and a new periarticular erosion of the distal first proximal phalanx (black arrowhead). Note the interval healing of the soft tissue of the fifth toe, with new subtle osteopenia of the fifth distal phalanx (white arrowhead).

Figure 2.

Diagram shows an algorithm for management of frostbite with thrombolytic therapy. CT = computed tomography, DBP = diastolic blood pressure, Hb = hemoglobin, Hct = hematocrit, IV = intravenous, PTT = partial thromboplastin time, SBP = systolic blood pressure, SPECT = single photon emission computed tomography. (Data are from references ,–.)

Figure 3a.

Third-degree frostbite of the hands in an 18-year-old man. (a) Dorsal photographs show bilateral digital edema with mixed clear and hemorrhagic blisters throughout both hands. (b)DSA images obtained at presentation show an abrupt occlusion in the right fourth digit ulnar proper digital artery at the level of the distal interphalangeal joint (arrowhead) and impaired perfusion of the tips of the right fourth digit and left third digit. (c)DSA images obtained after 12 hours of continuous intra-arterial tPA infusion via the ulnar arteries show improved distal perfusion bilaterally, with a short-segment persistent occlusion in the right fourth digit ulnar proper digital artery (arrowhead). The patient made a full recovery without further intervention.

Figure 3b.

Third-degree frostbite of the hands in an 18-year-old man. (a) Dorsal photographs show bilateral digital edema with mixed clear and hemorrhagic blisters throughout both hands. (b)DSA images obtained at presentation show an abrupt occlusion in the right fourth digit ulnar proper digital artery at the level of the distal interphalangeal joint (arrowhead) and impaired perfusion of the tips of the right fourth digit and left third digit. (c)DSA images obtained after 12 hours of continuous intra-arterial tPA infusion via the ulnar arteries show improved distal perfusion bilaterally, with a short-segment persistent occlusion in the right fourth digit ulnar proper digital artery (arrowhead). The patient made a full recovery without further intervention.

Figure 3c.

Third-degree frostbite of the hands in an 18-year-old man. (a) Dorsal photographs show bilateral digital edema with mixed clear and hemorrhagic blisters throughout both hands. (b)DSA images obtained at presentation show an abrupt occlusion in the right fourth digit ulnar proper digital artery at the level of the distal interphalangeal joint (arrowhead) and impaired perfusion of the tips of the right fourth digit and left third digit. (c)DSA images obtained after 12 hours of continuous intra-arterial tPA infusion via the ulnar arteries show improved distal perfusion bilaterally, with a short-segment persistent occlusion in the right fourth digit ulnar proper digital artery (arrowhead). The patient made a full recovery without further intervention.

Figure 4a.

Fourth-degree frostbite of the left hand in a 45-year-old woman. (a) Dorsal photograph shows gangrene throughout the distal aspects of the second through fifth digits. Note the sparing of the thumb. (b–d)DSA images obtained at presentation (b) and after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the ulnar artery show persistent occlusion of the second through fifth proper digital arteries distal to the metacarpophalangeal joints. Note the vasospasm of the ulnar artery at 12 hours (arrowhead in c), which complicates interpretation of the distal perfusion defects. The patient ultimately underwent amputation of the second through fifth digits through the mid proximal phalanges.

Figure 4b.

Fourth-degree frostbite of the left hand in a 45-year-old woman. (a) Dorsal photograph shows gangrene throughout the distal aspects of the second through fifth digits. Note the sparing of the thumb. (b–d)DSA images obtained at presentation (b) and after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the ulnar artery show persistent occlusion of the second through fifth proper digital arteries distal to the metacarpophalangeal joints. Note the vasospasm of the ulnar artery at 12 hours (arrowhead in c), which complicates interpretation of the distal perfusion defects. The patient ultimately underwent amputation of the second through fifth digits through the mid proximal phalanges.

Figure 4c.

Fourth-degree frostbite of the left hand in a 45-year-old woman. (a) Dorsal photograph shows gangrene throughout the distal aspects of the second through fifth digits. Note the sparing of the thumb. (b–d)DSA images obtained at presentation (b) and after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the ulnar artery show persistent occlusion of the second through fifth proper digital arteries distal to the metacarpophalangeal joints. Note the vasospasm of the ulnar artery at 12 hours (arrowhead in c), which complicates interpretation of the distal perfusion defects. The patient ultimately underwent amputation of the second through fifth digits through the mid proximal phalanges.

Figure 4d.

Fourth-degree frostbite of the left hand in a 45-year-old woman. (a) Dorsal photograph shows gangrene throughout the distal aspects of the second through fifth digits. Note the sparing of the thumb. (b–d)DSA images obtained at presentation (b) and after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the ulnar artery show persistent occlusion of the second through fifth proper digital arteries distal to the metacarpophalangeal joints. Note the vasospasm of the ulnar artery at 12 hours (arrowhead in c), which complicates interpretation of the distal perfusion defects. The patient ultimately underwent amputation of the second through fifth digits through the mid proximal phalanges.

Figure 5a.

Third-degree frostbite of the right foot in a 45-year-old woman. (a) Dorsal photograph shows diffuse swelling of the midfoot and toes, with both clear and hemorrhagic blisters. (b)DSA image obtained at presentation shows occlusion of the first through fifth digital arteries. (c, d)DSA images obtained after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the tibioperoneal trunk show restoration of perfusion in the first and second toes, with continued diminished perfusion of the distal third through fifth toes. The patient’s foot ultimately healed without surgical intervention.

Figure 5b.

Third-degree frostbite of the right foot in a 45-year-old woman. (a) Dorsal photograph shows diffuse swelling of the midfoot and toes, with both clear and hemorrhagic blisters. (b)DSA image obtained at presentation shows occlusion of the first through fifth digital arteries. (c, d)DSA images obtained after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the tibioperoneal trunk show restoration of perfusion in the first and second toes, with continued diminished perfusion of the distal third through fifth toes. The patient’s foot ultimately healed without surgical intervention.

Figure 5c.

Third-degree frostbite of the right foot in a 45-year-old woman. (a) Dorsal photograph shows diffuse swelling of the midfoot and toes, with both clear and hemorrhagic blisters. (b)DSA image obtained at presentation shows occlusion of the first through fifth digital arteries. (c, d)DSA images obtained after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the tibioperoneal trunk show restoration of perfusion in the first and second toes, with continued diminished perfusion of the distal third through fifth toes. The patient’s foot ultimately healed without surgical intervention.

Figure 5d.

Third-degree frostbite of the right foot in a 45-year-old woman. (a) Dorsal photograph shows diffuse swelling of the midfoot and toes, with both clear and hemorrhagic blisters. (b)DSA image obtained at presentation shows occlusion of the first through fifth digital arteries. (c, d)DSA images obtained after 12 (c) and 36 (d) hours of continuous intra-arterial tPA infusion via the tibioperoneal trunk show restoration of perfusion in the first and second toes, with continued diminished perfusion of the distal third through fifth toes. The patient’s foot ultimately healed without surgical intervention.

Figure 6a.

Third-degree frostbite of the toes in a 22-year-old man. (a) Dorsal photographs show bilateral diffuse discoloration of the toes and hemorrhagic blisters. (b)DSA images obtained at presentation show absent perfusion beyond the distal interphalangeal joints bilaterally. (c)DSA images obtained after 24 hours of continuous intra-arterial tPA infusion via the popliteal arteries show near-complete resolution. (d–f) Multiphase technetium 99m (99mTc) labeled–methylene diphosphonate (MDP) bone scintigraphic images of the feet obtained 1 month later because of persistent superficial wounds show preserved uptake throughout both feet in the plantar blood flow phase at 35 seconds (with toe and heel markers) (d), soft-tissue phase (without markers) (e), and 4.5-hour delayed phase (without markers) (f). Note the nonuniform uptake on the delayed phase image, with areas of increased uptake within the heels, medial midfeet, and first toes that correspond to areas of hyperemia on the blood flow and soft-tissue phase images. (g) Fused SPECT/CT image shows preserved tracer uptake throughout both feet. The patient made a full recovery without tissue loss or surgery.

Figure 6b.

Third-degree frostbite of the toes in a 22-year-old man. (a) Dorsal photographs show bilateral diffuse discoloration of the toes and hemorrhagic blisters. (b)DSA images obtained at presentation show absent perfusion beyond the distal interphalangeal joints bilaterally. (c)DSA images obtained after 24 hours of continuous intra-arterial tPA infusion via the popliteal arteries show near-complete resolution. (d–f) Multiphase technetium 99m (99mTc) labeled–methylene diphosphonate (MDP) bone scintigraphic images of the feet obtained 1 month later because of persistent superficial wounds show preserved uptake throughout both feet in the plantar blood flow phase at 35 seconds (with toe and heel markers) (d), soft-tissue phase (without markers) (e), and 4.5-hour delayed phase (without markers) (f). Note the nonuniform uptake on the delayed phase image, with areas of increased uptake within the heels, medial midfeet, and first toes that correspond to areas of hyperemia on the blood flow and soft-tissue phase images. (g) Fused SPECT/CT image shows preserved tracer uptake throughout both feet. The patient made a full recovery without tissue loss or surgery.

Figure 6c.

Third-degree frostbite of the toes in a 22-year-old man. (a) Dorsal photographs show bilateral diffuse discoloration of the toes and hemorrhagic blisters. (b)DSA images obtained at presentation show absent perfusion beyond the distal interphalangeal joints bilaterally. (c)DSA images obtained after 24 hours of continuous intra-arterial tPA infusion via the popliteal arteries show near-complete resolution. (d–f) Multiphase technetium 99m (99mTc) labeled–methylene diphosphonate (MDP) bone scintigraphic images of the feet obtained 1 month later because of persistent superficial wounds show preserved uptake throughout both feet in the plantar blood flow phase at 35 seconds (with toe and heel markers) (d), soft-tissue phase (without markers) (e), and 4.5-hour delayed phase (without markers) (f). Note the nonuniform uptake on the delayed phase image, with areas of increased uptake within the heels, medial midfeet, and first toes that correspond to areas of hyperemia on the blood flow and soft-tissue phase images. (g) Fused SPECT/CT image shows preserved tracer uptake throughout both feet. The patient made a full recovery without tissue loss or surgery.

Figure 6d.

Third-degree frostbite of the toes in a 22-year-old man. (a) Dorsal photographs show bilateral diffuse discoloration of the toes and hemorrhagic blisters. (b)DSA images obtained at presentation show absent perfusion beyond the distal interphalangeal joints bilaterally. (c)DSA images obtained after 24 hours of continuous intra-arterial tPA infusion via the popliteal arteries show near-complete resolution. (d–f) Multiphase technetium 99m (99mTc) labeled–methylene diphosphonate (MDP) bone scintigraphic images of the feet obtained 1 month later because of persistent superficial wounds show preserved uptake throughout both feet in the plantar blood flow phase at 35 seconds (with toe and heel markers) (d), soft-tissue phase (without markers) (e), and 4.5-hour delayed phase (without markers) (f). Note the nonuniform uptake on the delayed phase image, with areas of increased uptake within the heels, medial midfeet, and first toes that correspond to areas of hyperemia on the blood flow and soft-tissue phase images. (g) Fused SPECT/CT image shows preserved tracer uptake throughout both feet. The patient made a full recovery without tissue loss or surgery.

Figure 6e.

Third-degree frostbite of the toes in a 22-year-old man. (a) Dorsal photographs show bilateral diffuse discoloration of the toes and hemorrhagic blisters. (b)DSA images obtained at presentation show absent perfusion beyond the distal interphalangeal joints bilaterally. (c)DSA images obtained after 24 hours of continuous intra-arterial tPA infusion via the popliteal arteries show near-complete resolution. (d–f) Multiphase technetium 99m (99mTc) labeled–methylene diphosphonate (MDP) bone scintigraphic images of the feet obtained 1 month later because of persistent superficial wounds show preserved uptake throughout both feet in the plantar blood flow phase at 35 seconds (with toe and heel markers) (d), soft-tissue phase (without markers) (e), and 4.5-hour delayed phase (without markers) (f). Note the nonuniform uptake on the delayed phase image, with areas of increased uptake within the heels, medial midfeet, and first toes that correspond to areas of hyperemia on the blood flow and soft-tissue phase images. (g) Fused SPECT/CT image shows preserved tracer uptake throughout both feet. The patient made a full recovery without tissue loss or surgery.

Figure 6f.

Third-degree frostbite of the toes in a 22-year-old man. (a) Dorsal photographs show bilateral diffuse discoloration of the toes and hemorrhagic blisters. (b)DSA images obtained at presentation show absent perfusion beyond the distal interphalangeal joints bilaterally. (c)DSA images obtained after 24 hours of continuous intra-arterial tPA infusion via the popliteal arteries show near-complete resolution. (d–f) Multiphase technetium 99m (99mTc) labeled–methylene diphosphonate (MDP) bone scintigraphic images of the feet obtained 1 month later because of persistent superficial wounds show preserved uptake throughout both feet in the plantar blood flow phase at 35 seconds (with toe and heel markers) (d), soft-tissue phase (without markers) (e), and 4.5-hour delayed phase (without markers) (f). Note the nonuniform uptake on the delayed phase image, with areas of increased uptake within the heels, medial midfeet, and first toes that correspond to areas of hyperemia on the blood flow and soft-tissue phase images. (g) Fused SPECT/CT image shows preserved tracer uptake throughout both feet. The patient made a full recovery without tissue loss or surgery.

Figure 6g.

Third-degree frostbite of the toes in a 22-year-old man. (a) Dorsal photographs show bilateral diffuse discoloration of the toes and hemorrhagic blisters. (b)DSA images obtained at presentation show absent perfusion beyond the distal interphalangeal joints bilaterally. (c)DSA images obtained after 24 hours of continuous intra-arterial tPA infusion via the popliteal arteries show near-complete resolution. (d–f) Multiphase technetium 99m (99mTc) labeled–methylene diphosphonate (MDP) bone scintigraphic images of the feet obtained 1 month later because of persistent superficial wounds show preserved uptake throughout both feet in the plantar blood flow phase at 35 seconds (with toe and heel markers) (d), soft-tissue phase (without markers) (e), and 4.5-hour delayed phase (without markers) (f). Note the nonuniform uptake on the delayed phase image, with areas of increased uptake within the heels, medial midfeet, and first toes that correspond to areas of hyperemia on the blood flow and soft-tissue phase images. (g) Fused SPECT/CT image shows preserved tracer uptake throughout both feet. The patient made a full recovery without tissue loss or surgery.

Figure 7a.

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.

Figure 7b.

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.

Figure 7c.

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.

Figure 7d.

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.

Figure 7e.

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.

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.

Figure 8a.

Fourth-degree frostbite of the feet in a 65-year-old woman. (a) Plantar photographs show gangrene of the bilateral toes and superficial necrosis of the bilateral midfeet and heels. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe markers (arrowheads) show absent tracer uptake distal to the midfoot bilaterally in the plantar blood flow phase at 30 seconds (b), soft-tissue phase (c), and 4-hour delayed phase (d). Note that the level of deep tissue injury is greater than what might have been predicted at physical examination. (e, f) Fused SPECT/CT images show absent tracer uptake at the level of the mid metatarsals in the right foot (e) and just proximal to the metatarsophalangeal joints in the left foot (f). The patient subsequently underwent bilateral amputation of the feet, with full-thickness graft reconstruction at the same levels.

Figure 8b.

Fourth-degree frostbite of the feet in a 65-year-old woman. (a) Plantar photographs show gangrene of the bilateral toes and superficial necrosis of the bilateral midfeet and heels. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe markers (arrowheads) show absent tracer uptake distal to the midfoot bilaterally in the plantar blood flow phase at 30 seconds (b), soft-tissue phase (c), and 4-hour delayed phase (d). Note that the level of deep tissue injury is greater than what might have been predicted at physical examination. (e, f) Fused SPECT/CT images show absent tracer uptake at the level of the mid metatarsals in the right foot (e) and just proximal to the metatarsophalangeal joints in the left foot (f). The patient subsequently underwent bilateral amputation of the feet, with full-thickness graft reconstruction at the same levels.

Figure 8c.

Fourth-degree frostbite of the feet in a 65-year-old woman. (a) Plantar photographs show gangrene of the bilateral toes and superficial necrosis of the bilateral midfeet and heels. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe markers (arrowheads) show absent tracer uptake distal to the midfoot bilaterally in the plantar blood flow phase at 30 seconds (b), soft-tissue phase (c), and 4-hour delayed phase (d). Note that the level of deep tissue injury is greater than what might have been predicted at physical examination. (e, f) Fused SPECT/CT images show absent tracer uptake at the level of the mid metatarsals in the right foot (e) and just proximal to the metatarsophalangeal joints in the left foot (f). The patient subsequently underwent bilateral amputation of the feet, with full-thickness graft reconstruction at the same levels.

Figure 8d.

Fourth-degree frostbite of the feet in a 65-year-old woman. (a) Plantar photographs show gangrene of the bilateral toes and superficial necrosis of the bilateral midfeet and heels. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe markers (arrowheads) show absent tracer uptake distal to the midfoot bilaterally in the plantar blood flow phase at 30 seconds (b), soft-tissue phase (c), and 4-hour delayed phase (d). Note that the level of deep tissue injury is greater than what might have been predicted at physical examination. (e, f) Fused SPECT/CT images show absent tracer uptake at the level of the mid metatarsals in the right foot (e) and just proximal to the metatarsophalangeal joints in the left foot (f). The patient subsequently underwent bilateral amputation of the feet, with full-thickness graft reconstruction at the same levels.

Figure 8e.

Fourth-degree frostbite of the feet in a 65-year-old woman. (a) Plantar photographs show gangrene of the bilateral toes and superficial necrosis of the bilateral midfeet and heels. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe markers (arrowheads) show absent tracer uptake distal to the midfoot bilaterally in the plantar blood flow phase at 30 seconds (b), soft-tissue phase (c), and 4-hour delayed phase (d). Note that the level of deep tissue injury is greater than what might have been predicted at physical examination. (e, f) Fused SPECT/CT images show absent tracer uptake at the level of the mid metatarsals in the right foot (e) and just proximal to the metatarsophalangeal joints in the left foot (f). The patient subsequently underwent bilateral amputation of the feet, with full-thickness graft reconstruction at the same levels.

Figure 8f.

Fourth-degree frostbite of the feet in a 65-year-old woman. (a) Plantar photographs show gangrene of the bilateral toes and superficial necrosis of the bilateral midfeet and heels. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe markers (arrowheads) show absent tracer uptake distal to the midfoot bilaterally in the plantar blood flow phase at 30 seconds (b), soft-tissue phase (c), and 4-hour delayed phase (d). Note that the level of deep tissue injury is greater than what might have been predicted at physical examination. (e, f) Fused SPECT/CT images show absent tracer uptake at the level of the mid metatarsals in the right foot (e) and just proximal to the metatarsophalangeal joints in the left foot (f). The patient subsequently underwent bilateral amputation of the feet, with full-thickness graft reconstruction at the same levels.

Figure 9a.

Fourth-degree frostbite of the feet in a 46-year-old man with a history of congestive heart failure. (a) Dorsal photographs show bilateral toe gangrene, which is more extensive in the right foot. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe and heel markers show absent tracer uptake beyond the right midfoot in the plantar blood flow phase at 100 seconds (b), soft-tissue phase (c), and 5.5-hour delayed phase (d). Note absent tracer uptake in the left fourth and fifth toes (arrowhead in c) on the soft-tissue phase image. Also note the lack of osseous uptake on the delayed phase image in d, a finding attributed to a combination of impaired local delivery of tracer and the patient’s low cardiac output. Late delayed phase images should be obtained 18–24 hours after tracer injection if osseous uptake is absent on initial delayed phase images. (e) Fused SPECT/CT image of the feet obtained 24 hours after tracer administration delineates the level of tracer cutoff in the right foot as just distal to the tarsometatarsal joints. (f, g) Three-dimensional lateral (f) and two-dimensional dorsoplantar (g) SPECT/CT images show that tracer uptake is also absent in the left fourth and fifth toes (arrowheads). The patient subsequently underwent a right below-the-knee amputation and left fourth and fifth toe amputations.

Figure 9b.

Fourth-degree frostbite of the feet in a 46-year-old man with a history of congestive heart failure. (a) Dorsal photographs show bilateral toe gangrene, which is more extensive in the right foot. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe and heel markers show absent tracer uptake beyond the right midfoot in the plantar blood flow phase at 100 seconds (b), soft-tissue phase (c), and 5.5-hour delayed phase (d). Note absent tracer uptake in the left fourth and fifth toes (arrowhead in c) on the soft-tissue phase image. Also note the lack of osseous uptake on the delayed phase image in d, a finding attributed to a combination of impaired local delivery of tracer and the patient’s low cardiac output. Late delayed phase images should be obtained 18–24 hours after tracer injection if osseous uptake is absent on initial delayed phase images. (e) Fused SPECT/CT image of the feet obtained 24 hours after tracer administration delineates the level of tracer cutoff in the right foot as just distal to the tarsometatarsal joints. (f, g) Three-dimensional lateral (f) and two-dimensional dorsoplantar (g) SPECT/CT images show that tracer uptake is also absent in the left fourth and fifth toes (arrowheads). The patient subsequently underwent a right below-the-knee amputation and left fourth and fifth toe amputations.

Figure 9c.

Fourth-degree frostbite of the feet in a 46-year-old man with a history of congestive heart failure. (a) Dorsal photographs show bilateral toe gangrene, which is more extensive in the right foot. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe and heel markers show absent tracer uptake beyond the right midfoot in the plantar blood flow phase at 100 seconds (b), soft-tissue phase (c), and 5.5-hour delayed phase (d). Note absent tracer uptake in the left fourth and fifth toes (arrowhead in c) on the soft-tissue phase image. Also note the lack of osseous uptake on the delayed phase image in d, a finding attributed to a combination of impaired local delivery of tracer and the patient’s low cardiac output. Late delayed phase images should be obtained 18–24 hours after tracer injection if osseous uptake is absent on initial delayed phase images. (e) Fused SPECT/CT image of the feet obtained 24 hours after tracer administration delineates the level of tracer cutoff in the right foot as just distal to the tarsometatarsal joints. (f, g) Three-dimensional lateral (f) and two-dimensional dorsoplantar (g) SPECT/CT images show that tracer uptake is also absent in the left fourth and fifth toes (arrowheads). The patient subsequently underwent a right below-the-knee amputation and left fourth and fifth toe amputations.

Figure 9d.

Fourth-degree frostbite of the feet in a 46-year-old man with a history of congestive heart failure. (a) Dorsal photographs show bilateral toe gangrene, which is more extensive in the right foot. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe and heel markers show absent tracer uptake beyond the right midfoot in the plantar blood flow phase at 100 seconds (b), soft-tissue phase (c), and 5.5-hour delayed phase (d). Note absent tracer uptake in the left fourth and fifth toes (arrowhead in c) on the soft-tissue phase image. Also note the lack of osseous uptake on the delayed phase image in d, a finding attributed to a combination of impaired local delivery of tracer and the patient’s low cardiac output. Late delayed phase images should be obtained 18–24 hours after tracer injection if osseous uptake is absent on initial delayed phase images. (e) Fused SPECT/CT image of the feet obtained 24 hours after tracer administration delineates the level of tracer cutoff in the right foot as just distal to the tarsometatarsal joints. (f, g) Three-dimensional lateral (f) and two-dimensional dorsoplantar (g) SPECT/CT images show that tracer uptake is also absent in the left fourth and fifth toes (arrowheads). The patient subsequently underwent a right below-the-knee amputation and left fourth and fifth toe amputations.

Figure 9e.

Fourth-degree frostbite of the feet in a 46-year-old man with a history of congestive heart failure. (a) Dorsal photographs show bilateral toe gangrene, which is more extensive in the right foot. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe and heel markers show absent tracer uptake beyond the right midfoot in the plantar blood flow phase at 100 seconds (b), soft-tissue phase (c), and 5.5-hour delayed phase (d). Note absent tracer uptake in the left fourth and fifth toes (arrowhead in c) on the soft-tissue phase image. Also note the lack of osseous uptake on the delayed phase image in d, a finding attributed to a combination of impaired local delivery of tracer and the patient’s low cardiac output. Late delayed phase images should be obtained 18–24 hours after tracer injection if osseous uptake is absent on initial delayed phase images. (e) Fused SPECT/CT image of the feet obtained 24 hours after tracer administration delineates the level of tracer cutoff in the right foot as just distal to the tarsometatarsal joints. (f, g) Three-dimensional lateral (f) and two-dimensional dorsoplantar (g) SPECT/CT images show that tracer uptake is also absent in the left fourth and fifth toes (arrowheads). The patient subsequently underwent a right below-the-knee amputation and left fourth and fifth toe amputations.

Figure 9f.

Fourth-degree frostbite of the feet in a 46-year-old man with a history of congestive heart failure. (a) Dorsal photographs show bilateral toe gangrene, which is more extensive in the right foot. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe and heel markers show absent tracer uptake beyond the right midfoot in the plantar blood flow phase at 100 seconds (b), soft-tissue phase (c), and 5.5-hour delayed phase (d). Note absent tracer uptake in the left fourth and fifth toes (arrowhead in c) on the soft-tissue phase image. Also note the lack of osseous uptake on the delayed phase image in d, a finding attributed to a combination of impaired local delivery of tracer and the patient’s low cardiac output. Late delayed phase images should be obtained 18–24 hours after tracer injection if osseous uptake is absent on initial delayed phase images. (e) Fused SPECT/CT image of the feet obtained 24 hours after tracer administration delineates the level of tracer cutoff in the right foot as just distal to the tarsometatarsal joints. (f, g) Three-dimensional lateral (f) and two-dimensional dorsoplantar (g) SPECT/CT images show that tracer uptake is also absent in the left fourth and fifth toes (arrowheads). The patient subsequently underwent a right below-the-knee amputation and left fourth and fifth toe amputations.

Figure 9g.

Fourth-degree frostbite of the feet in a 46-year-old man with a history of congestive heart failure. (a) Dorsal photographs show bilateral toe gangrene, which is more extensive in the right foot. (b–d) Multiphase 99mTc-MDP bone scintigraphic images with toe and heel markers show absent tracer uptake beyond the right midfoot in the plantar blood flow phase at 100 seconds (b), soft-tissue phase (c), and 5.5-hour delayed phase (d). Note absent tracer uptake in the left fourth and fifth toes (arrowhead in c) on the soft-tissue phase image. Also note the lack of osseous uptake on the delayed phase image in d, a finding attributed to a combination of impaired local delivery of tracer and the patient’s low cardiac output. Late delayed phase images should be obtained 18–24 hours after tracer injection if osseous uptake is absent on initial delayed phase images. (e) Fused SPECT/CT image of the feet obtained 24 hours after tracer administration delineates the level of tracer cutoff in the right foot as just distal to the tarsometatarsal joints. (f, g) Three-dimensional lateral (f) and two-dimensional dorsoplantar (g) SPECT/CT images show that tracer uptake is also absent in the left fourth and fifth toes (arrowheads). The patient subsequently underwent a right below-the-knee amputation and left fourth and fifth toe amputations.

Figure 10a.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10b.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10c.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10d.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10e.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10f.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10g.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10h.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 10i.

Fourth-degree frostbite of the right hand in a 65-year-old woman. (a) Palmar photograph obtained at bone scintigraphy shows tip gangrene of all digits. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show absent tracer uptake within the distal second, third, and fourth digits and absent tracer uptake distal to the fifth digit metacarpophalangeal joint in the palmar blood flow phase at 120 seconds (b), soft-tissue phase (c), and 3.5-hour delayed phase (d). Note the preservation of tracer uptake throughout the thumb. (e–g) Fused SPECT/CT images of the right hand (obtained in different projections) show the exact level of bone necrosis within the right second, third, fourth, and fifth digits, with preserved uptake throughout the thumb. (h, i) Palmar (h) and dorsal (i) photographs obtained 1 week after bone scintigraphy demonstrate the level of tissue loss previously defined at SPECT/CT.

Figure 11a.

Third-degree frostbite of the right foot and fourth-degree frostbite of the left foot in a 39-year-old man. (a) Plantar photographs obtained after blister aspiration and débridement show large areas of freshly débrided tissue involving the toes and plantar surfaces of both feet. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show an absence of tracer uptake in the distal left foot in the plantar blood flow phase at 100 seconds (with toe markers) (b), soft-tissue phase (with toe markers) (c), and 6-hour delayed phase (without markers) (d). (e) Fused SPECT/CT image clearly demonstrates the level of tracer cutoff at the metatarsophalangeal joints in the left second through fifth toes. The patient underwent amputation of the left second through fifth toes but was unwilling to have his left first toe removed at that time. (f) Repeat fused SPECT/CT image obtained 8 days later shows absent tracer uptake within the left first toe (arrowhead) at the identical level to that seen at previous SPECT/CT.

Figure 11b.

Third-degree frostbite of the right foot and fourth-degree frostbite of the left foot in a 39-year-old man. (a) Plantar photographs obtained after blister aspiration and débridement show large areas of freshly débrided tissue involving the toes and plantar surfaces of both feet. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show an absence of tracer uptake in the distal left foot in the plantar blood flow phase at 100 seconds (with toe markers) (b), soft-tissue phase (with toe markers) (c), and 6-hour delayed phase (without markers) (d). (e) Fused SPECT/CT image clearly demonstrates the level of tracer cutoff at the metatarsophalangeal joints in the left second through fifth toes. The patient underwent amputation of the left second through fifth toes but was unwilling to have his left first toe removed at that time. (f) Repeat fused SPECT/CT image obtained 8 days later shows absent tracer uptake within the left first toe (arrowhead) at the identical level to that seen at previous SPECT/CT.

Figure 11c.

Third-degree frostbite of the right foot and fourth-degree frostbite of the left foot in a 39-year-old man. (a) Plantar photographs obtained after blister aspiration and débridement show large areas of freshly débrided tissue involving the toes and plantar surfaces of both feet. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show an absence of tracer uptake in the distal left foot in the plantar blood flow phase at 100 seconds (with toe markers) (b), soft-tissue phase (with toe markers) (c), and 6-hour delayed phase (without markers) (d). (e) Fused SPECT/CT image clearly demonstrates the level of tracer cutoff at the metatarsophalangeal joints in the left second through fifth toes. The patient underwent amputation of the left second through fifth toes but was unwilling to have his left first toe removed at that time. (f) Repeat fused SPECT/CT image obtained 8 days later shows absent tracer uptake within the left first toe (arrowhead) at the identical level to that seen at previous SPECT/CT.

Figure 11d.

Third-degree frostbite of the right foot and fourth-degree frostbite of the left foot in a 39-year-old man. (a) Plantar photographs obtained after blister aspiration and débridement show large areas of freshly débrided tissue involving the toes and plantar surfaces of both feet. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show an absence of tracer uptake in the distal left foot in the plantar blood flow phase at 100 seconds (with toe markers) (b), soft-tissue phase (with toe markers) (c), and 6-hour delayed phase (without markers) (d). (e) Fused SPECT/CT image clearly demonstrates the level of tracer cutoff at the metatarsophalangeal joints in the left second through fifth toes. The patient underwent amputation of the left second through fifth toes but was unwilling to have his left first toe removed at that time. (f) Repeat fused SPECT/CT image obtained 8 days later shows absent tracer uptake within the left first toe (arrowhead) at the identical level to that seen at previous SPECT/CT.

Figure 11e.

Third-degree frostbite of the right foot and fourth-degree frostbite of the left foot in a 39-year-old man. (a) Plantar photographs obtained after blister aspiration and débridement show large areas of freshly débrided tissue involving the toes and plantar surfaces of both feet. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show an absence of tracer uptake in the distal left foot in the plantar blood flow phase at 100 seconds (with toe markers) (b), soft-tissue phase (with toe markers) (c), and 6-hour delayed phase (without markers) (d). (e) Fused SPECT/CT image clearly demonstrates the level of tracer cutoff at the metatarsophalangeal joints in the left second through fifth toes. The patient underwent amputation of the left second through fifth toes but was unwilling to have his left first toe removed at that time. (f) Repeat fused SPECT/CT image obtained 8 days later shows absent tracer uptake within the left first toe (arrowhead) at the identical level to that seen at previous SPECT/CT.

Figure 11f.

Third-degree frostbite of the right foot and fourth-degree frostbite of the left foot in a 39-year-old man. (a) Plantar photographs obtained after blister aspiration and débridement show large areas of freshly débrided tissue involving the toes and plantar surfaces of both feet. (b–d) Multiphase 99mTc-MDP bone scintigraphic images show an absence of tracer uptake in the distal left foot in the plantar blood flow phase at 100 seconds (with toe markers) (b), soft-tissue phase (with toe markers) (c), and 6-hour delayed phase (without markers) (d). (e) Fused SPECT/CT image clearly demonstrates the level of tracer cutoff at the metatarsophalangeal joints in the left second through fifth toes. The patient underwent amputation of the left second through fifth toes but was unwilling to have his left first toe removed at that time. (f) Repeat fused SPECT/CT image obtained 8 days later shows absent tracer uptake within the left first toe (arrowhead) at the identical level to that seen at previous SPECT/CT.