Diagnostic Accuracy and Surgical Utility of MRI in Complicated Diabetic Foot

Abstract

Introduction: Diabetic foot complications pose a significant public health hazard and have negative effect on life quality. These complications are associated with increased risk of amputations and premature death. So focus is increasing on early treatment of complicated diabetic foot.

Aim: To assess the diagnostic accuracy and surgical utility of MRI in complicated diabetic foot.

Materials and methods: Thirty four complicated diabetic patients were evaluated prospectively. Initially x-ray was done and a provisional management plan was formulated. Later T1W, T2W and FSat sequences of the affected foot and ankle was carried out. The soft tissue, tendons and osseous apparatus were evaluated and subsequently compared with histopathological examination. Before and after MRI, change in management plan was marked. Previously operated cases with persistent ulcer of affected foot were excluded from the study.

Results: Twenty two males and 12 females with mean age of 52±8.8 years were analysed. The sensitivity of MRI for tenosynovitis and osteomyelitis was 88% and 100% respectively. The specificity for the same was 100% and 90%. Of all 34 cases, MRI reshapes surgical planning in 23.5% cases (8 patients). The difference between MRI and histopathological findings was evaluated statistically using Fisher-Z test and the proportion of difference between these two groups was not significant as values for tenosynovitis was Z=0.50 (p-value >0.05) and for osteomyelitis Z= 0.54 (p-value>0.05).

Conclusion: The result indicates that MRI is a sensitive and accurate imaging modality for evaluation of diabetic foot and for planning proper treatment and the MRI correlates significantly with the surgical finding.

Keywords: Accurate imaging; Diabetic foot complications; Health hazard.

[Table/Fig-4]:

a) Wagner grade 1 ulcer present over planter surface of foot; b) X-ray showing no bony or soft tissue abnormality. Initially was thought to be managed conservatively; c) MRI shows the presence of abscess in planter surface of third toe which surgically proven to be correct.

[Table/Fig-5]:

a) A 29-year-old lady with Wagner grade 3 ulcer over the dorsum of great toe; b) AP radiograph of foot showing soft tissue swelling; c) Sagittal post contrast MRI section shows cortical disruption of the distal and proximal phalanx, but no involvement of the metatarsophalangeal joint or first metatarsal. As a result, only first ray amputation was done.