A Reperfusion BOLD-MRI Tissue Perfusion Protocol Reliably Differentiate Patients with Peripheral Arterial Occlusive Disease from Healthy Controls.

Kristina Törngren,Stefanie Eriksson,Mårten Falkenberg,Åse A. Johnsson,Jonathan Arvidsson,Carl Sjöberg,Joakim Nordanstig,Kerstin Lagerstrand

doi:10.3390/jcm10163643

Abstract

There is no established technique that directly quantifies lower limb tissue perfusion. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) is an MRI technique that can determine skeletal muscle perfusion. BOLD-MRI relies on magnetic differences of oxygenated and deoxygenated hemoglobin, and regional changes in oxy/deoxyhemoglobin ratio can be recorded by T2* weighted MRI sequences. We aimed to test whether BOLD-MRI can differentiate lower limb tissue perfusion in peripheral arterial occlusive disease (PAOD) patients and healthy controls. Twenty-two PAOD patients and ten healthy elderly volunteers underwent lower limb BOLD-MRI. Reactive hyperemia was provoked by transient cuff compression and images of the gastrocnemius and soleus muscles were continuously acquired at rest, during ischemia and reperfusion. Key BOLD parameters were baseline T2* absolute value and time to T2* peak value after cuff deflation (TTP). Correlations between imaging parameters and ankle-brachial index (ABI) was investigated. The mean TTP was considerably prolonged in PAOD patients compared to healthy controls (m. gastrocnemius: 111 ± 46 versus 48 ± 22 s, p = 0.000253; m. soleus: 100 ± 42 versus 41 ± 30 s, p = 0.000216). Both gastrocnemius and soleus TTP values correlated strongly with ABI (−0.82 and −0.78, p < 0.01). BOLD-MRI during reactive hyperemia differentiated most PAOD patients from healthy controls. TTP was the most decisive parameter and strongly correlated with the ABI.

Highlights

Further characterization of the ischemic state, feasibility of revascularization and pre-procedural planning is mainly based on vascular imaging techniques, including duplex ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) [2]
While it is conceivable that several of these dynamic signal responses might hold key insights into the physiological state of the tissue microvasculature response, this study focused on the reperfusion phase, and explored the hypothesis that the quantitative BOLD-Magnetic resonance imaging (MRI)
The observed changes from T2* baseline value to hyperemia peak value (HPV minus BL = overshoot) were lower in peripheral arterial occlusive disease (PAOD) patients than in healthy controls, but this was only significant in the gastrocnemius muscle

Summary

Introduction

Peripheral arterial occlusive disease (PAOD) is a large and increasing public health issue [1]. Further characterization of the ischemic state, feasibility of revascularization and pre-procedural planning is mainly based on vascular imaging techniques, including duplex ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) [2]. While all these imaging techniques currently provide high resolution images of the arterial tree, there is still no established imaging technique that directly quantifies the crucial pathophysiological process in PAOD—the tissue perfusion and, in particular, the oxygenation of peripheral skeletal muscle. As all revascularization procedures for PAOD aim to improve ischemic tissue perfusion, an imaging tool that can characterize and quantify tissue ischemia in the lower limb would potentially be of value both in the diagnostic process and in treatment outcome evaluations in PAOD patients

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