Cellulitis: foot ulcers: diabetes mellitus: MRI helped diagnose deep-seated infection.

Clinical bottom line (level 4)

Deep-seated infection was common in patients with diabetic foot ulcers or cellulitis who required hospital admission.
MRI helped diagnose (LR+3.9) and exclude (LR-0.12) this.

Cook et al: British Journal of Surgery 1996; 83: 245-248

Expires November 2004

The study

Setting: acute hospital, UK

22 patients (aged range 23 to 86 years; median 67, 64% male) admitted with foot ulcers and cellulitis secondary to diabetes mellitus (10 required insulin;12 with discharging ulcers, 8 with digital gangrene)

Independent unblinded reference standard, applied in all patients from a consecutive inappropriate spectrum.
Reference standard:

surgery or follow-up on prolonged antibiotics

Diagnostic test: MRI of the affected foot

The evidence

pre-test probability of deep-seated infection: 46%, (95% CI: 26% to 66%)

diagnostic test	deep-seated infection	no infection	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
positive MRI	10	3	3.94 (1.4 to 10.8)	77%	0.12 (0.02 to 0.78)	9%
total	11	13

One MRI scan was not useful due to patient movement.

Comments

No cost data was given, but MRI is expensive in general.

Citation

Cook TA, Rahim N, Simpson HC, et al: Magnetic resonance imaging in the management of diabetic foot infection. British Journal of Surgery 1996; 83: 245-248

Search Terms: cellulitis and diagnosis
Contributor: John Epling and Chris Ball, November 2000
Reviewer:

_{Clinical Question.}

_Patient	_{diabetic foot ulcers and cellulitis}
_{Intervention or Exposure}	_MRI
_Outcome	_{deep-seated infection}