Gangrene
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Advanced Imaging of the Diabetic Foot and Its Complications
Copyright 1999 T. Learch, A. Gentili. All rights reserved.
Revised: November 16, 2004.

 

The word gangrene comes from the Latin word gangraena, an eating sore. Gangrene is death and decay of a body part due to deficiency of blood supply and is frequent complication in the diabetic foot.

Dry gangrene can be diagnosed on conventional radiographs, especially in the toes, when marked thinning of the soft tissue shadows is present. MR imaging is more dramatic with marked signal loss on all sequences secondary to absence of mobile protons necessary for signal. Administration of intravenous gadolinium may show abrupt signal loss at the level of the gangrenous change. Bone marrow signal changes may be present suggesting osteomyelitis. This finding may be secondary to coexistent osteomyelitis or to ischemic changes in the bone. Differentiation of these two entities cannot be accomplished by MR imaging.

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Gangrene

Two patients with dry gangrene of toes.

21-year-old man with newly diagnosed diabetes.  Photograph of foot demonstrates dry gangrene of the second toe.

50-year-old man with diabetes.  PA radiograph demonstrates marked soft tissue thinning of the 2nd and 3rd digits. The osseous structures, however, are intact without evidence of destructive change.

Sagittal MR images of 1st toe with wet gangrene. T1 and STIR images demonstrate lack of signal distally. Sagittal T1 weighted images with fat saturation post intravenous gadolinium demonstrate extensive tissue necrosis.

52-year-old man with long standing diabetes and black 1st toe. Sagittal T1 weighted image with fat saturation post intravenous gadolinium enhancement demonstrates absent signal of the distal soft tissues and bone of the 1st toe secondary to dry gangrene. On comparison radiographs, the 1st distal phalange was intact and present. On MR images, the distal phalange is difficult to image due to lack of mobile protons in dry gangrenous tissues. (Click on the images to see larger versions)


A B

61-year-old man with diabetes and wet gangrene. Sagital STIR (A) and sagital T1 weighted image with fat saturation post intravenous gadolinium enhancement (B) demonstrate extensive soft tissue necrosis. Lack of gadolinium enhancement of this area is consistent with soft tissue necrosis and gangrene. (Click on the images to see larger versions)

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Advanced Imaging of the Diabetic Foot and Its Complications
Copyright 1999 T. Learch, A. Gentili. All rights reserved.
Revised: April 29, 2006.
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