Differential Diagnosis of Intraplaque Hemorrhage and Dissection on High-Resolution MR Imaging in Patients with Focal High Signal of the Vertebrobasilar Artery on TOF Imaging

Comparative analysis of imaging features and stroke-related factors between posterior circulation atherosclerosis and intramural hematoma-type dissection

AIM

To compare the features detected by high resolution magnetic resonance vessel wall imaging (HR-VWI) between posterior circulation atherosclerosis and intramural hematoma (IMH)-type dissection, and to identify indicators related to cerebral ischemic events.

MATERIALS AND METHODS

Clinical and HR-VWI data of 55 patients with posterior circulation IMH-type dissection and 132 patients with posterior circulation atherosclerosis collected between October 2017 and October 2023 were analyzed retrospectively. Two radiologists independently extracted the imaging features. Multivariable logistic regression was used to identify factors independently associated with stroke.

RESULTS

Compared with patients with atherosclerosis, those with IMH-type dissection were younger, with a lower prevalence of diabetes and hypertriglyceridemia, lower hypertension grade, enhanced grade, remodeling index (RI), vertebrobasilar artery/brainstem ratio, and prevalence of nonsmooth surface, and higher prevalence of intraluminal thrombus (ILT), lumen (LA), wall area (WA), and total vessel area (TVA). In patients with stroke, those with IMH-type dissection were younger, with a lower prevalence of diabetes, and degree of hypertension, and higher RI, WA, TVA, and the prevalence of ILT. Multivariable logistic regression showed that RI (odds ratio [OR], 0.37; 95% CI, 0.17-0.77) and normalized wall index (NWI) (OR, 39.02; 95% CI, 2.19-695.35) were risk factors for stroke in patients with dissection, and LA (OR, 1.52; 95% CI, 1.12-2.06) and NWI (OR, 60.84; 95% CI 3.70-998.06) were risk factors for atherosclerotic stroke.

CONCLUSION

Patients with posterior circulation IMH-type dissection had greater potential for positive remodeling than those with atherosclerosis. The arterial remodeling capacity was closely related to stroke risk.

Spontaneous intracranial vertebral artery dissections presenting with subarachnoid hemorrhage

BACKGROUND

Vertebral artery dissection (VAD) is an infrequent source of subarachnoid hemorrhage (SAH), with a high mortality rate, primarily due to the risk of rebleeding both before and after medical intervention. This paper provides a comprehensive analysis of the anatomy, pathophysiology, clinical presentation, treatment strategies, and outcomes of intracranial vertebral artery dissections that result in subarachnoid hemorrhage.

METHODS

Comprehensive five-year literature review (2018-2022) and a retrospective analysis of patient records from our institution between 2016 and 2022. We included studies with a minimum of 5 patients.

RESULTS

The study incorporated ten series from the literature and 22 cases from CHUM. Key anatomical factors increasing the risk of VAD include the vertebral artery's origin from the aortic arch, asymmetry of the vertebral artery, and its tortuosity. Patients may display specific collagen and genetic abnormalities. The occurrence of VAD appears to be more prevalent in men. Those with a ruptured intracranial VAD typically show prodromal symptoms and present with severe SAH. Rebleeding within the first 24 h is frequent. While standard imaging methods are usually adequate for VAD diagnosis, they may not provide detailed information about the perforator anatomy. Treatment approaches include both deconstructive and reconstructive methods.

CONCLUSION

Ruptured VAD is a critical, life-threatening condition. Many patients have a poor neurological status at presentation, and rebleeding prior to treatment is a significant concern. Deconstructive techniques are most effective in preventing rebleeding, whereas the efficacy of reconstructive techniques needs more investigation.

In-hospital recurrence and functional outcome between ischemic stroke caused by intracranial arterial dissection and intracranial atherosclerosis: Retrospective cohort study of the nationwide multicenter registry

BACKGROUND

Intracranial arterial dissection (ICAD) and intracranial atherosclerotic stenosis (ICAS) are often difficult to differentiate, and studies on their background factors and prognosis are scarce. Information on prognosis, including recurrence, is necessary for stroke care, and clarification of epidemiological and clinical differences between the two diseases is important for appropriately handling their heterogeneity. This study aimed to determine the association of ICAD and ICAS with in-hospital recurrence and prognosis and compare their background and clinical findings.

METHODS

In this multicenter cohort study, we retrospectively analyzed data from the Saiseikai Stroke Database. Adults with ischemic stroke caused by ICAD or ICAS were included in this study. Patients' backgrounds and clinical findings were compared between the ICAD and ICAS groups. The outcome showed an association of ICAD with in-hospital recurrence of ischemic stroke and poor functional outcome relative to ICAS. Multivariable logistic regression analyses were performed to calculate the adjusted odds ratios (ORs) for ICAD with 95% confidence intervals (CIs) for each outcome.

RESULTS

Among 15,622 patients registered in the Saiseikai Stroke Database, 2,020 were enrolled (ICAD group: 89; ICAS group: 1,931). In the ICAD group, 65.2% of the patients were aged <64 years. Vascular lesion location was more common in ICAD with the vertebral artery [42 (47.2%)], anterior cerebral artery [20 (22.5%)], and middle cerebral artery (MCA) [16 (18.0%)], and in ICAS with MCA 1046 (52.3%). Multivariable logistic regression analyses of the association between ICAD and in-hospital recurrence and poor functional outcome yielded a crude OR (95% CI) of 3.26 (1.06-9.97) and 0.97 (0.54-1.74), respectively, relative to ICAS.

CONCLUSION

ICAD was associated with a higher in-hospital recurrence than ICAS; however, there was no significant difference in prognosis between the two groups. Differences in background characteristics and vessel lesions may be of interest in these two diseases.

Vessel Wall Magnetic Resonance Imaging in Cerebrovascular Diseases

Cerebrovascular diseases are a leading cause of disability and death worldwide. The definition of stroke etiology is mandatory to predict outcome and guide therapeutic decisions. The diagnosis of pathological processes involving intracranial arteries is especially challenging, and the visualization of intracranial arteries’ vessel walls is not possible with routine imaging techniques. Vessel wall magnetic resonance imaging (VW-MRI) uses high-resolution, multiparametric MRI sequences to directly visualize intracranial arteries walls and their pathological alterations, allowing a better characterization of their pathology. VW-MRI demonstrated a wide range of clinical applications in acute cerebrovascular disease. Above all, it can be of great utility in the differential diagnosis of atherosclerotic and non-atherosclerotic intracranial vasculopathies. Additionally, it can be useful in the risk stratification of intracranial atherosclerotic lesions and to assess the risk of rupture of intracranial aneurysms. Recent advances in MRI technology made it more available, but larger studies are still needed to maximize its use in daily clinical practice.