Contrast-Enhanced Magnetic Resonance Imaging Based T1-Mapping and Extracellular Volume Fractions are Associated with Peripheral Artery Disease

Abstract

Background: Extracellular volume fraction (ECV), measured with contrast-enhanced magnetic resonance imaging (CE-MRI), has been utilized to study myocardial fibrosis but its role in peripheral artery disease (PAD) remains unknown. We hypothesized that T1-mapping and ECV differ between PAD patients and matched-controls. Methods and Results: A total of 37 individuals (18 PAD, 19 controls) underwent 3.0T CE-MRI at the mid-calf. T1-mapping was done before and after gadolinium contrast with a motion corrected Modified Look Locker Inversion Recovery (MOLLI) pulse sequence. T1 values were calculated with a 3-parameter Levenberg-Marquardt curve fitting algorithm. T1-maps were quantified in 5 calf muscle compartments (anterior [AM], lateral [LM], and deep posterior [DM] muscle groups; soleus [SM], and gastrocnemius [GM] muscles). Averaged peak blood pool T1 values were obtained from the posterior (PT) and anterior tibialis (AT); and peroneal artery (PE). PAD ECV was calculated for each muscle group. T1 values and ECV are heterogeneous across calf muscle compartments. Native peak T1 values of the AM, LM, and DM were significantly higher in PAD patients compared to controls (all p<0.028). ECV of the AM and SM were significantly higher in PAD patients compared to controls (AM: 26.4% (21.2, 31.6) vs. 17.3% (10.2, 25.1), p=0.046; SM: 22.7% (19.5, 27.8) vs. 13.8% (10.2, 19.1), p=0.020). Conclusions: Native peak T1 values and ECV fractions of several calf muscle compartments are higher in PAD patients compared with matched-controls. These data suggest a potential utility of ECV to noninvasively determine skeletal muscle fibrosis in PAD.

Contrast-Enhanced Magnetic Resonance Imaging Based T1 Mapping and Extracellular Volume Fractions Are Associated with Peripheral Artery Disease

“…This study adds to the growing body of evidence that T1 mapping and ECV quantification are providing reproducible measures of tissue characterization including but not limited to diffuse fibrosis and other pathophysiological changes in response to inflammation, the hallmark of atherosclerosis and PAD [15,16,25].…”

“…Previous studies reported the high reproducibility of myocardial T1 mapping [14,15]. However, the role of T1 mapping and ECV values remains poorly understood in PAD [16]. For the present work, we studied the role of the T1 mapping and ECV quantification of the skeletal calf muscles in PAD patients and controls.…”