Peripheral Arterial Wall Imaging Using Contrast-Enhanced, Susceptibility-Weighted Phase Imaging

Abstract

To demonstrate improved delineation of peripheral arterial wall in susceptibility-weighted imaging (SWI) phase images by using gadolinium contrast agent. Superficial femoral arteries were imaged using high-resolution SWI in 11 healthy volunteers before and after injection of gadopentetate dimeglumine. Two postcontrast scans started 1 minute and 11 minutes after injection, respectively. Eight of the 11 volunteers also underwent double-inversion recovery turbo-spin-echo (TSE) scans. The same resolution and matrix size were used between SWI and TSE studies, and TSE locations were matched to SWI images. Arterial lumen-wall phase difference and phase contrast-to-noise ratio were measured and compared between precontrast and postcontrast SWI measurements. The lumen and wall areas measured on both TSE and matching SWI images were analyzed for agreement. Two other volunteers participated in a double-echo gradient-echo study. Results were compared to SWI. By injecting gadolinium contrast agent, phase difference changed by 54.5% and -1.6%, and phase contrast-to-noise ratio changed by 85.7% and 27.0% for the first and second postcontrast scans, respectively. Morphological measurements showed insignificant difference between TSE and SWIs based on paired t tests; good agreements in Bland-Altman plots were achieved. The double-echo gradient-echo study had similar phase measurements as SWI. Contrast-enhanced phase imaging improves arterial wall delineation in SWI of peripheral arterial wall. Contrast-enhanced SWI is a promising vessel wall imaging technique.