Hypo-attenuating Berry Sign as a Novel Imaging Marker of Ruptured Aneurysm in Patients with Subarachnoid Hemorrhage; a Diagnostic Accuracy Study.

Introduction: Aneurysmal subarachnoid hemorrhage (SAH) constitutes a life-threatening condition, and identifying the ruptured aneurysm is essential for further therapy. This study aimed to evaluate the diagnostic accuracy of hypo-attenuating berry sign (HBS) observed on computed tomography (CT) scan in distinguishing ruptured aneurysms. Methods: In this diagnostic accuracy study, patients who had SAH and underwent non-enhanced brain CT scan were recruited. The HBS was defined as a hypo-attenuating area with an identifiable border in the blood-filled hyper-dense subarachnoid space. The screening performance characteristics of HBS in identifying ruptured aneurysms were calculated considering the digital subtraction angiography (DSA) as the gold standard. Results: A total of 129 aneurysms in 131 patients were analyzed. The overall sensitivity and specificity of HBS in the diagnosis of aneurysms were determined to be 78.7% (95%CI: 73.1% - 83.4%) and 70.7% (95%CI: 54.3% - 83.4%), respectively. Notably, the sensitivity increased to 90.9% (95%CI: 84.3% - 95.0%) for aneurysms larger than 5mm. The level of inter-observer agreement for assessing the presence of HBS was found to be substantial (kappa=0.734). The diagnostic accuracy of HBS in individuals exhibited enhanced specificity, sensitivity, and reliability when evaluating patients with a solitary aneurysm or assessing ruptured aneurysms. The multivariate logistic regression analysis revealed a statistically significant relationship between aneurysm size and the presence of HBS (odds ratios of 1.667 (95%CI: 1.238 - 2.244; p < 0.001) and 1.696 (95%CI: 1.231 - 2.335; p = 0.001) for reader 1 and reader 2, respectively). Conclusions: The HBS can serve as a simple and easy-to-use indicator for identifying a ruptured aneurysm and estimating its size in SAH patients.  .

Understanding the Clinical Implications of Intracranial Arterial Calcification Using Brain CT and Vessel Wall Imaging.

Background and Purpose: Intracranial arterial calcification (IAC) has been the focus of much attention by clinicians and researchers as an indicator of intracranial atherosclerosis, but correlations of IAC patterns (intimal or medial) with the presence of atherosclerotic plaques and plaque stability are still a matter of debate. Our study aimed to assess the associations of IAC patterns identified on computed tomography (CT) with the presence of plaque detected on vessel wall magnetic resonance imaging and plaque stability. Materials and Methods: Patients with stroke or transient ischemic attack and intracranial artery stenosis were recruited. IAC was detected and localized (intima or media) on non-contrast CT images. Intracranial atherosclerotic plaques were identified using vessel wall magnetic resonance imaging and matched to corresponding CT images. Associations between IAC patterns and culprit atherosclerotic plaques were assessed by using multivariate regression. Results: Seventy-five patients (mean age, 63.4 ± 11.6 years; males, 46) were included. Two hundred and twenty-one segments with IAC were identified on CT in 66 patients, including 86 (38.9%) predominantly intimal calcifications and 135 (61.1%) predominantly medial calcifications. A total of 72.0% of intimal calcifications coexisted with atherosclerotic plaques, whereas only 10.2% of medial calcifications coexisted with plaques. Intimal calcification was more commonly shown in non-culprit plaques than culprit plaques (25.9 vs. 9.4%, P = 0.008). The multivariate mixed logistic regression adjusted for the degree of stenosis showed that intimal calcification was significantly associated with non-culprit plaques (OR, 2.971; 95% CI, 1.036-8.517; P = 0.043). Conclusion: Our findings suggest that intimal calcification may indicate the existence of a stable form of atherosclerotic plaque, but plaques can exist in the absence of intimal calcification especially in the middle cerebral artery.

Postmortem Study Exploring Distribution and Patterns of Intracranial Artery Calcification.

Background and Purpose- Intracranial artery calcification detected by computed tomography is associated with ischemic stroke as an indicator of intracranial atherosclerosis. However, little is known about its histopathology. This study aimed to explore the intracranial calcification patterns and their associations with atherosclerotic plaques. Methods- We recruited 32 adult autopsy cases to assess the calcification patterns and distributions in the middle cerebral artery, vertebral artery, and basilar artery. The relationships of calcification patterns with plaque phenotype and luminal stenosis were evaluated. The calcification patterns on computed tomography were correlated with that on histology. Results- Visible calcifications were detected within 37 (39%) segments, including 25 segments with intimal calcification, 6 segments with internal elastic lamina calcification, 3 segments with adventitial calcification, and 3 segments with concurrent calcification. Calcification occurred more often in the vertebral artery (51%), followed by the middle cerebral artery (35%) and basilar artery (14%; P<0.01 for vertebral artery versus basilar artery). Internal elastic lamina calcification was predominantly detected in the vertebral artery (7/8, 88%). All of the 27 (100%) intimal calcifications were present in the progressive atherosclerotic lesions ( P<0.001), whereas only 3/8 (38%) internal elastic lamina calcifications and 4/6 (67%) adventitial calcifications were associated with progressive plaques. Arteries with intimal calcification had more severe luminal stenosis than those without (46% versus 21%; P<0.001). Conclusions- Our histological findings indicate that the presence of intracranial artery calcification has 3 patterns, including intimal, internal elastic lamina, and adventitial calcifications. But only intimal calcification is related with progressive atherosclerotic lesions, indicative of a proxy for intracranial atherosclerosis.

Risk factors analysis of mirror aneurysms: A multi-center retrospective study based on clinical and demographic profile of patients.

As a special subgroup of multiple intracranial aneurysms, mirror aneurysms are located bilaterally on the corresponding intracranial arteries. The current study sought to compare the clinical and demographic features of patients harboring mirror aneurysm, and to elucidate the corresponding risk factors. We performed a retrospective cohort study of 2641 intracranial aneurysms patients, who were admitted to our hospitals between January 2005 and June 2014. Patients were subdivided into three groups based on the inclusion criteria: (i) single (n=2250); (ii) non-mirror multiple (n=285); and (iii) mirror aneurysms (n=106). Clinical and demographic files of the three groups were collected and compared, and medical histories including stroke, hyperlipemia, hypertension, hyperglycemia, valvular heart disease were considered as potential risk factors. Potential morphological reasons for mirror cerebral aneurysms rupture, including aneurysms size, irregular walls and cerebral hemispheric dominance, were also compared. Our data showed that the male to female ratio of mirror aneurysms patients was 1:3.61, which was significantly different from that of single aneurysm (1:1.27) and multiple aneurysms (1:2.00). The prevalence of mirror aneurysms in women is higher than that in men (P<0.001). Older patients (especially 60-69 years old) also appear to be more vulnerable to mirror aneurysm than single aneurysm (P<0.001). In 84 mirror aneurysm patients the aneurysms were located on the internal carotid arteries (79.2%), most typically at the PComA or in the Cavernous ICA. Patients with medical history of hyperlipemia appear to have an increased risk of harboring mirror aneurysms. Larger aneurysm size and presence of an irregular aneurysm wall appear to be the morphological factors that predispose for mirror aneurysms rupture.