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.   .