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 hypoattenuating 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). Conclusion: The HBS can serve as a simple and easy -to -use indicator for identifying a ruptured aneurysm and estimating its size in SAH patients.