The Evolution of an Intramural Haematoma in Spontaneous Brachiocephalic Artery Dissection based on MRI Data

Abstract

Dissection of the internal carotid (ICA) and vertebral arteries (VA) is one of the most common causes of ischaemic stroke in younger people. Despite wider use of modern neuroimaging techniques in clinical practice, and greater diagnostic capabilities for assessing structural changes in blood vessels, detection of spontaneous dissection remains low. The aim of the study was to identify patterns of change in the signal characteristics of an intramural haematoma in patients with spontaneous ICA and VA dissection on MRI and MR angiography (MRA), during the first three months after onset of clinical symptoms, as well as to create an optimal scan protocol. Based on changes in the K value and a visual assessment of the signal characteristics of the intramural haematoma, the study found that the signal intensity from the haematoma depends on the time of the examination. In the acute and chronic stages of dissection, the K value approaches 1 under Т1 FS and time-of-flight (TOF) MRA modes, and the intramural hematoma “merges” with the surrounding soft tissues, making it difficult to detect during these periods. Between 7 days and 2 months, the haematoma has a hyperintense signal and the K value is >1 under Т1 FS and TOF-MRA modes (p < 0.05). A comparison of K value data from different time periods made us add the T1 FS mode to the scan protocol for patients with suspected spontaneous dissection, in addition to the standard TOF-MRA, in order to improve the intramural haematoma imaging.