MRI Evaluation of Bone Marrow Changes in the Diabetic Foot: A Practical Approach

ABSTRACT

One of the most important roles of magnetic resonance (MR) in imaging of the diabetic foot is to differentiate between the common and often comorbid pathologies that present with abnormal bone marrow signal. The primary diagnostic challenges in this setting are to distinguish osteomyelitis from reactive bone marrow edema, neuroarthropathy from osteomyelitis, and the sterile from the superinfected neuropathic joint. Whereas both osteomyelitis and reactive marrow edema share increased T2 signal, osteomyelitis is confirmed by T1 hypointensity in the bone marrow and reactive edema demonstrates isolated T2 signal hyperintensity. In distinguishing osteomyelitis from neuroarthropathy, a localized or contiguously spreading forefoot focus of abnormal bone marrow away from the subchondral surface and adjacent to a skin ulcer, cellulitis, abscess, or sinus tract would be indicative of osteomyelitis. A midfoot, subchondral, periarticular, or polyarticular distribution of findings in the absence of a contiguous focus of skin disruption would strongly support neuroarthropathy. Parameters that have been successfully correlated with acute infection superimposed on neuroarthropathy include diffuse bone marrow signal abnormality, progressive subarticular enhancement, loss of subchondral cysts, and the presence of the MRI “ghost sign.”

KEYWORDS

Diabetic foot - magnetic resonance imaging - neuroarthropathy - osteomyelitis

REFERENCES

• 1 Russell J M, Peterson J J, Bancroft L W. MR imaging of the diabetic foot.  Magn Reson Imaging Clin N Am. 2008;  16 (1) 59-70 vi
• 2 Donovan A, Schweitzer M E. Current concepts in imaging diabetic pedal osteomyelitis.  Radiol Clin North Am. 2008;  46 (6) 1105-1124 vii
• 3 Wu J S, Gorbachova T, Morrison W B, Haims A H. Imaging-guided bone biopsy for osteomyelitis: are there factors associated with positive or negative cultures?.  AJR Am J Roentgenol. 2007;  188 (6) 1529-1534
• 4 Marcus C D, Ladam-Marcus V J, Leone J, Malgrange D, Bonnet-Gausserand F M, Menanteau B P. MR imaging of osteomyelitis and neuropathic osteoarthropathy in the feet of diabetics.  Radiographics. 1996;  16 (6) 1337-1348
• 5 Schweitzer M E, Daffner R H, Weissmen B N et al.. ACR appropriateness criteria on suspected osteomyelitis in patients with diabetes mellitus.  J Amer Col Radiol. 2008;  5 (8) 881-886
• 6 Kapoor A, Page S, Lavalley M, Gale D R, Felson D T. Magnetic resonance imaging for diagnosing foot osteomyelitis: a meta-analysis.  Arch Intern Med. 2007;  167 (2) 125-132
• 7 Jeffcoate W J, Lipsky B A. Controversies in diagnosing and managing osteomyelitis of the foot in diabetes.  Clin Infect Dis. 2004;  39 (Suppl 2) S115-S122
• 8 Ledermann H P, Morrison W B, Schweitzer M E. MR image analysis of pedal osteomyelitis: distribution, patterns of spread, and frequency of associated ulceration and septic arthritis.  Radiology. 2002;  223 (3) 747-755
• 9 Collins M S, Schaar M M, Wenger D E, Mandrekar J N. T1-weighted MRI characteristics of pedal osteomyelitis.  AJR Am J Roentgenol. 2005;  185 (2) 386-393
• 10 Johnson P W, Collins M S, Wenger D E. Diagnostic utility of T1-weighted MRI characteristics in evaluation of osteomyelitis of the foot.  AJR Am J Roentgenol. 2009;  192 (1) 96-100
• 11 Lipsky B A, Pecoraro R E, Wheat L J. The diabetic foot: soft tissue and bone infection.  Infect Dis Clin North Am. 1990;  4 (3) 409-432
• 12 Tomas M B, Patel M, Marwin S E, Palestro C J. The diabetic foot.  Br J Radiol. 2000;  73 (868) 443-450
• 13 Chatha D S, Cunningham P M, Schweitzer M E. MR imaging of the diabetic foot: diagnostic challenges.  Radiol Clin North Am. 2005;  43 (4) 747-759 ix
• 14 Schweitzer M E, Morrison W B. MR imaging of the diabetic foot.  Radiol Clin North Am. 2004;  42 (1) 61-71 vi
• 15 Ledermann H P, Morrison W B. Differential diagnosis of pedal osteomyelitis and diabetic neuroarthropathy: MR imaging.  Semin Musculoskelet Radiol. 2005;  9 (3) 272-283
• 16 Tan P L, Teh J. MRI of the diabetic foot: differentiation of infection from neuropathic change.  Br J Radiol. 2007;  80 (959) 939-948
• 17 Bancroft L W. MR imaging of infectious processes of the knee.  Radiol Clin North Am. 2007;  45 (6) 931-941 v
• 18 Donovan A, Schweitzer M E. Use of MR imaging in diagnosing diabetes-related pedal osteomyelitis.  Radiographics. 2010;  30 (3) 723-736
• 19 Mueller M J, Minor S D, Diamond J E, Blair III V P. Relationship of foot deformity to ulcer location in patients with diabetes mellitus.  Phys Ther. 1990;  70 (6) 356-362
• 20 Panchbhavi V K, Hecox S E. All that is gas is not gas gangrene: mechanical spread of gas in the soft tissues. A case report.  J Bone Joint Surg Am. 2006;  88 (6) 1345-1348
• 21 Cofield R H, Morrison M J, Beabout J W. Diabetic neuroarthropathy in the foot: patient characteristics and patterns of radiographic change.  Foot Ankle. 1983;  4 (1) 15-22
• 22 Armstrong D G, Todd W F, Lavery L A, Harkless L B, Bushman T R. The natural history of acute Charcot's arthropathy in a diabetic foot specialty clinic.  J Am Podiatr Med Assoc. 1997;  87 (6) 272-278
• 23 Ramesh S, Santh L G, Panchapakesa R C, Rukmangatha R S, Vasanthi N. Diabetic forefoot neuroarthropathy—“Sucked candy stick” appearance.  J Indian Rheumatol Assoc. 2003;  11 55-58
• 24 Veves A, Giurini J, LoGerfo F W. The Diabetic Foot. 2nd ed. Totowa, NJ: Humana Press; 2006
• 25 Chatha D S, Cunningham P M, Schweitzer M E. MR imaging of the diabetic foot: diagnostic challenges.  Radiol Clin North Am. 2005;  43 (4) 747-759 ix
• 26 Ahmadi M E, Morrison W B, Carrino J A, Schweitzer M E, Raikin S M, Ledermann H P. Neuropathic arthropathy of the foot with and without superimposed osteomyelitis: MR imaging characteristics.  Radiology. 2006;  238 (2) 622-631