CT-perfusion in peripheral arterial disease – Correlation with angiographic and hemodynamic parameters

Abstract

ObjectiveThe purpose of this study was the assessment of volumetric CT-perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) of the lower extremities, comparing it with established angiographic and hemodynamic parameters.Materials and methodsThirty-five consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularization were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment. Hemodynamic parameters, specifically ankle-brachial pressure index (ABI), ankle blood pressure (ABP), peak systolic velocity (PSV), and segmental pulse oscillography (SPO) level, were determined. Lesion length and degree of collateralization were assessed by interventional angiography. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters and correlations between CTP, hemodynamic and angiographic parameters were assessed with non-parametric tests.ResultsThe cohort consisted of 27 subjects with an occlusion, and eight with a high-grade stenosis. The mean blood flow (BF) was 7.71 ± 2.96 ml/100ml*min-1, mean blood volume (BV) 0.71 ± 0.33 ml/100ml, and mean mean transit time (MTT) 7.22 ± 2.66 s. BF and BV were higher in subjects with longer lesions, and BV was higher in subjects with lower ABI. Significant correlations were found between lesion length and BV (r = 0.65) and BF (r = 0.52). Significant inverse correlations were found between BV and ABI and between BV and ABP (r = -0.56, for both correlations).ConclusionsIn our study, we have shown the feasibility of CTP for the assessment of PAD. In the future, this quantitative method might serve as a non-invasive method, possibly complementing the diagnostic workup of patients with peripheral arterial disease.

CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

“…Recapitulating our results, we have shown that CTP values obtained in calf musculature, which represents the anatomic substrate for the clinical hallmark of critical limb ischemia, i.e. claudication, might represent an appropriate overview of local PAD [10]. CTP accounts for physiological compensation mechanisms of the body and functional collateralisation.…”

“…1 a Blood flow before and after revascularisation. b Blood volume before and after revascularisation of the dependent tissue, and this complex situation is not represented by simple, large vessel-based parameters [10].…”

“…Hemodynamic assessment was performed as previously described in all patients prior to and after revascularisation [ 10 ]. Evidence of hemodynamically significant obstruction was established by non-invasive vascular testing, pulse volume recordings, and duplex ultrasound imaging studies.…”

“…Such a method should ideally not only display the morphological surrogate that is partly the reason the symptoms of the patients but reflect the whole extent of disease. Such a method cannot be exclusively based upon the blood stream in the largest vessels of the extremities, which are the basic underlying physiologic parameters of the ABI [5,10].…”

“…Recently, efforts were made to investigate PAD using volumetric computed tomography perfusion (CTP) [10][11][12]. CTP parameters were shown to reflect microvessel density in tumours and other different human tissues [13,14].…”