A prospective study was carried out of 22 patients admitted with 25 di
abetic foot infections. All had cellulitis, 12 had discharging ulcers
and eight had digital gangrene. In one case magnetic resonance imaging
(MRI) was unhelpful owing to patient movement. Thirteen scans suggest
ed deep-seated infection, including abscess (ten), osteomyelitis (seve
n) and ankle effusion (one). Overall, imaging provided a specificity o
f 77 per cent, a positive predictive value of 77 per cent, a sensitivi
ty of 98 per cent and a negative predictive value of 91 per cent. MRI
is valuable in determining the presence and extent of infection, which
allows appropriate planning of surgical intervention.