Comparison of carotid vessel wall area measurements using three different contrast-weighted black blood MR imaging techniques

Measuring carotid artery plaque burden from MRI is a reliable method for monitoring regression and progression of atherosclerosis. However, to measure all available images would be very time consuming, and in practice the image quality (IQ) of these images may be inconsistent, which can directly impact the quality of measurement. It is hypothesized that if IQ is comparable among different contrast weighted images, then carotid artery area measurements obtained from different contrast images of the same location will produce identical results. To test this, T1, proton density and T2 weighted images were acquired from ten patients (51 ± 7 years old). Carotid lumen and vessel wall area was measured using a custom designed software program. The results showed strong agreement evidenced with only small differences on both lumen (mean: 40.5 mm2) and wall (mean: 52.6 mm2) area measurement among different weighted images. The maximum absolute mean differences are less than 2.7 mm2 and 4.4 mm2, and 90th percentile of the absolute differences are 5.6 mm2 and 8.2 mm2 respectively. In conclusion, different contrast weighted images with high and comparable IQ will yield similar results in lumen and vessel wall area measurement. At each matched location, it is recommended that the image with the highest IQ be used for area measurement.