P604Clinical feasibility assessment of a novel Quantitative Multi-contrast Atherosclerosis Characterization (qMATCH) sequence for carotid plaque quantification

Abstract Background Conventional protocol contrast MRI (cMRI) for evaluating carotid artery atherosclerosis is clinically under-utilized due to complex scanning procedures and long scan time. Recently, the Quantitative Multi-contrast Atherosclerosis Characterization (qMATCH) has been proposed, which allows comprehensive and quantitative assessment of atherosclerosis including MRA, dark-blood vessel wall morphology, and T1/T2 mapping with an 8-minute single scan (Figure1). However, the diagnostic accuracy and feasibility of qMATCH has not been validated in clinical circumstances. Purpose To evaluate the diagnostic accuracy of quantitative plaque analysis of qMATCH compared with cMRI Method We prospectively enrolled 43 patients who have carotid plaques diagnosed by carotid ultrasound. cMRI was performed along with qMATCH scan. All imaging data were acquired with a clinical 3T scanner using a 64-channel head & neck coil. In the current analysis, we evaluated the diagnostic accuracy of qMATCH in the quantitative assessment of carotid plaque. Plaque area measurements using dark-blood wall images with qMATCH were compared with corresponding cross-sectional T1/T2-weighted images with cMRI as references values (Figure 2). These inter-technique comparisons included linear regression with Pearson correlation and Bland-Altman analyses to assess the mean inter-technique differences (biases) and limits of agreements. Result Among 90 segments, mean plaque areas measured by cMRI and qMATCH were 43.83±21.21 mm2 and 42.47±19.23mm2, respectively (mean differences, −1.36±8.12mm2; p for a paired t-test, 0.073). Correlation coefficient showed excellent correlation between plaque areas measured by cMRI and qMATCH (r=0.943, p<0.001) (Figure 3). Bland-Altman plot showed excellent agreement in plaque areas between the two methods (Figure 4). Conclusion Quantitative carotid plaque burden analysis by a novel sequence with qMATCH is feasible and accurate compared with conventional MRI. Given that qMATCH can reduce scan time and allow quantitative relaxometry mapping, fast and accurate carotid plaque analysis would be feasible. Further studies to evaluate the accuracy of qualitative plaque analysis should be performed to confirm the “all-in-one” assessment of carotid atherosclerosis using qMATCH.