Arterial occlusion duration affects the cuff-induced hyperemic response in skeletal muscle BOLD perfusion imaging as shown in young healthy subjects

Abstract

ObjectiveDynamic BOLD MRI with cuff compression, inducing ischemia and post-occlusive hyperemia in skeletal muscle, has been pointed out as a potential diagnostic tool to assess peripheral limb perfusion. The objective was to explore the robustness of this technique and its sensitivity to the occlusion duration.Materials and methodsBOLD images were acquired at 3 T in 14 healthy volunteers. {mathrm{T}}_{2}^{*}-imaging with 5- and 1.5-min occlusions were acquired and several semi-quantitative BOLD parameters were derived from ROI-based {mathrm{T}}_{2}^{*}-time curves. Differences in parameters from the two different occlusion durations were evaluated in the gastrocnemius and soleus muscles using non-parametrical tests. Intra- and inter-scan repeatability were evaluated with coefficient of variation.ResultsLonger occlusion duration resulted in an increased hyperemic signal effect yielding significantly different values (p < 0.05) in gastrocnemius for all parameters describing the hyperemic response, and in soleus for two of these parameters. Specifically, 5-min occlusion yielded steeper hyperemic upslope in gastrocnemius (41.0%; p < 0.05) and soleus (59.7%; p = 0.03), shorter time to half peak in gastrocnemius (46.9%; p = 0.00008) and soleus (33.5%; p = 0.0003), and shorter time to peak in gastrocnemius (13.5%; p = 0.02). Coefficients of variation were lower than percentage differences that were found significant.DiscussionFindings show that the occlusion duration indeed influences the hyperemic response and thus should play a part in future methodological developments.