The following is a summary of “Vessel Wall Imaging Features of Spontaneous Intracranial Carotid Artery Dissection,” published in the May 2024 issue of Neurology by Wasserman et al.
Despite its promise for detecting intracranial dissections, Vessel wall imaging (VWI) in this context lacks validation with pathological confirmation.
Researchers conducted a retrospective study to assess VWI’s accuracy in identifying the rare occurrence of spontaneous intracranial carotid dissection (sICD), using postmortem validation as the gold standard.
They assessed VWI features of sICD, which were confirmed through postmortem specimen analysis in one patient. The features comprised luminal enhancement within an outer wall exhibiting hypoenhancement, with narrowing observed in the mid to distal ophthalmic (C6) segment while relatively sparing the communicating (C7) segment. The VWI scans underwent scrutiny to detect patients who display corresponding imaging features, lack indications of other vasculopathy (e.g., inflammatory conditions, intracranial atherosclerotic disease [ICAD]), and possess images of adequate quality. The VWI features of sICD were compared to patients with ICAD features using the Fisher exact test, considering multiple samples, focusing on similar C6 narrowing and relatively spared C7.
The results showed 407 VWI examinations, 8 patients with 14 cases of spontaneous sICD, all women aged 30 to 56 years, with 6 (75%) being bilateral. All patients with sICD had risk factors such as recent postpartum state, fibromuscular dysplasia, and hypertension, with 3 (37.5%) having intracranial dissections elsewhere. Initial angiography diagnosed seven (87.5%) with Moyamoya syndrome. Lesions ranged from thin flaps to thick tissue along the carotid artery wall. Compared with 10 intracranial carotid plaques in 8 patients with ICAD, sICD exhibited more robust (84.6% vs. 20.0%, P=0.003–0.025) and more homogeneous (61.5% vs. 0.0%, P=0.005–0.069) enhancement, and less positive remodeling (0.0% vs. 60.0%, P=0.004–0.09). The T1 hyperintensity was found in 5 sICDs in 3 patients but not in ICAD. Three patients with serial imaging (8- to 39.8-month maximum intervals) showed minimal to no stenosis, wall thickening, or enhancement changes.
Investigators concluded that VWI could effectively distinguish sICD from ICAD based on enhancement patterns, remodeling degree, and clinical presentation, particularly in young females with dissection risk factors.