Tissue-muscle perfusion assessed by one day ^99mTc-MIBI rest-dipyridamol scintigraphy in non-diabetic and diabetic patients

Aim: To determine the perfusion reserve of the lower limbs using the method ^99mTc-MIBI (rest-dipyridamole) perfusion scintigraphy (one-day protocol) in the diagnostic evaluation of peripheral artery disease (PAD) in patients with and without diabetes mellitus (DM).

Material and methods: We performed tissue-muscle perfusion scintigraphy (TMPS) of the lower limbs, through one-day rest-dipyridamole protocol with ^99mTc-MIBI in 24 patients, divided in two groups according to the presence of diabetes - patients with DM (Dp) 13/24 (54%), 2 males and 9 female patients, age 63±13 years and patients without DM (NDp) 11/24 (46%), 3 males and 10 females, age 61±14 years.

Results: In the dynamic phase of the rest study, the time of maximum activity (Tmax), in the early arterial phase, of the calf region was significantly prolonged in Dp compared to NDp, with lower accumulation of the radiotracer in the 1st minute (85%/87% in Dp vs. 89%/90% in NDp, ns). 4/11 of NDp (36.4%) and 7/13 of Dp (53.8%) registered pathological value of the inter-extremity index of the calves in the stress study. Perfusion reserve (PR) of the thighs (LT, RT) and calves (LC, RC) calculated with the formula "(ROI stress-ROI rest)×100%/ROI rest", was significantly lower in Dp: LT: 28±19% vs. 43±24% in NDp, p<0.05; RT: 27±17% vs. 40±25% in NDp, p<0.05; LC: 22±15% vs. 36±15% in NDp, p<0.01; RC: 25±15% vs. 38±14% in NDp, p<0.01.

Conclusion: This one-day protocol (rest-dipyridamole with ^99mTc-MIBI) of perfusion scintigraphy of lower limbs is considered as a useful procedure in PAD assessment, especially the asymptomatic form. TMPS of the lower limbs in our study indicated that perfusion reserve in patients with DM was significantly lower, compared to the patients without diabetes.