Dynamic change of carotid intraplaque hemorrhage volume in subjects with mild carotid stenosis

Background and Purpose: Early detection of intraplaque hemorrhage (IPH) in the carotid artery is important as it is correlated with an increased risk of cerebral ischemic events. We examined changes in IPH with magnetic resonance imaging (MRI) over an extended follow-up period in patients with mild carotid stenosis. Materials and Methods: From November 2013 to November 2015, we retrospectively reviewed cerebral MRI of 2036 patients, including magnetization-prepared rapid acquisition with gradient-echo (MPRAGE) sequences obtained with a 3.0 T (T) MRI unit. An experienced neuroradiologist reviewed all studies and found 38 patients with carotid IPH and carotid stenosis that were categorized as mild (<30%), according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Twenty-five patients agreed to join this study and signed informed consent for (MPRAGE) sequence imaging. We used semi-automated software to measure IPH volume on both the initial and follow up scans. Results: The median follow-up time of patients with mild carotid stenosis and IPH was 33.3 months. IPH volume increased in 10 of 27 carotid arteries (37.0%), with a mean volume increase of 42.6 ± 44.0 mm³. IPH volume decreased in 17 of 27 carotid arteries (63%), with a mean volume decrease of 17.2 ± 22.8 mm³. Two patients without IPH at baseline showed IPH development on follow-up imaging. There were no significant differences in patient demographics between the two groups. Conclusions: Carotid IPH volume in subjects with mild carotid stenosis can change over time and may not be correlated with any typical patient demographics.