Abstract 12582: A Novel Magnetic Resonance Imaging Protocol to Assess Skeletal Leg Muscle Perfusion in Peripheral Arterial Disease Subjects
Background: Current imaging technologies have limited capabilities to assess the functional status of leg muscles in peripheral arterial disease (PAD) subjects. We hypothesize that skeletal muscle perfusion in the leg is a functional marker of PAD which can be non-invasively imaged and quantified with MRI.
Methods: Twenty individuals (13 PAD subjects [median age=72 years, median ABI=0.6], 7 healthy controls [median age=35 years]) underwent a novel MR perfusion imaging protocol using a 36-element bilateral lower extremity coil with a 3.0T MRI system. Perfusion imaging was performed at mid-calf level post hyperemia induced by supra-systolic inflation of a bilateral blood-pressure cuff positioned above the knee. Rapid cuff deflation was synchronized with the administration of a Gadolinium-based contrast agent (15ml) and imaging was commenced with a high resolution saturation recovery gradient echo pulse sequence (repetition time=409.57ms; echo time=1.23ms). MRI signal intensities (SI) were semi-automatically quantified pre and post contrast in the axial images for 5 distinct leg muscle compartments: anterior; lateral; deep posterior; soleus muscle; and gastrocnemius muscle. MRI SI were averaged over both legs.
Results:(Table) Post-contrast signal enhancement was significantly increased in all 5 muscle compartments for healthy controls (p=0.016) and PAD subjects (p=<0.001). Pre-contrast SI were significantly decreased in all muscle groups in PAD subjects compared with controls (p<0.01 for all muscle groups). Similarly, maximal SI was significantly reduced in the lateral, soleus, and gastrocnemius muscles for PAD patients (p<0.001, p=0.024, p<0.001). There was no significant difference between cross-sectional areas of individual muscle compartment.
Conclusion: PAD patients present with significantly reduced pre- and post contrast signal intensities compared with healthy controls suggesting impaired leg muscle function.
- © 2012 by American Heart Association, Inc.