Multi imaging approach with low field MRA in diabetic foot ulcer: hospital based study

Abstract

The aim of study was to assess the usefulness of non-invasive imaging in patient of diabetic foot ulcer with low field MRA and determine the severity and extent of lower extremity arterial disease in diabetic patients with poor socio economic status. The present study is based on 38 patients who were referred to Department of Radiology with complaint of non-healing ulcer of lower limb of more than 6 weeks duration. The patients were subjected to plain radiographs, Duplex scanning with color flow imaging and MR angiography (non contrast enhanced). The modalities were used to detect vascular calcifications, osteomyelitis, bone resorption, deformities, thickening of arteries, plaques, spectral waveforms, collaterals. MRA was used to assess subjective calibre of vessels and presence of stenosis. The patients were categorised according to age and a note of ulcer duration made. Grade of ulcer was determined (wagner’s criteria) and note was made of severity of stenosis (cossman). Radiographs assessed bony destruction and vascular calcification. Doppler assessed degree of stenosis and vascularity. MRI gave a road map of vascular integrity. Integration of the tests provided a satisfactory diagnostic protocol to decide future prognosis and assessment of advancement of disease process. The data was subjected to calculation of mean, standard deviation and Pearson’s chi square test. p value < 0.05 was considered to be stastically significant. Majority of patients were males (80%) and highest incidence was noted in fourth-fifth decade (43.33%). 47.37% presented with grade III ulcer. Duplex scanning with color flow imaging was more accurate and sensitive in picking up calcified arteries, focal plaques, stenosed arteries and abnormal arterial waveforms. These patients had co-existent lower extremity arterial disease with moderate to severe stenosis (i.e. on comparision with peak systolic velocity (PSV), p < 0.05. Ulcer grade had stastically significant correlation with severity of stenosis, (p < 0.05). However MRA did not corroborate the same findings. It proved to be only 60% sensitive when compared to Duplex scanning (100%). Plain radiographs and color Doppler evaluation plays an indispensable role in imaging and evaluating patients with chronic non-healing ulcer of diabetic foot. MRA gives crucial information regarding parameters like vascularity, degree of stenosis, and extent of disease. Not all patients in our set up afford CTA or CEMRA followed by DSA or cost of stenting. When the diagnostic workup in our cases suggested poor prognosis or non salvageable vascular compromise the patient was counseled against further investigation and advised surgery. By using this approach many financially constrained patients are benefitted from unnecessary and costly diagnostic workup.