Purpose: To evaluate the accuracy of multidetector-row CT angiography (CTA) for the diagnosis of large-vessel vasospasm following subarachnoid hemorrhage by comparison to digital subtraction angiography (DSA). Methods: Thirty-three patients with acute subarachnoid hemorrhage were enrolled in a prospective study and underwent a total of 40 CTA and DSA examinations within 24 h of each other. Two neuroradiologists reviewed the CTA examinations independently. A third neuroradiologist blinded to the CTA results reviewed the DSA examinations. In each patient, for both techniques, 23 arterial segments were evaluated for their degree of narrowing; the reviewers were asked to attribute every narrowing to ‘vasospasm’ or ‘hypoplasia’. Agreement between CTA and DSA for the degree of narrowing, and agreement between the two CTA readers, were calculated using weighted ĸ-coefficients. Sensitivity, specificity, accuracy, positive and negative predictive value (NPV) of CTA to detect large-vessel vasospasm were calculated considering DSA as the gold standard. Results: Substantial correlation (ĸ = 0.638) was found between CTA and DSA for the detection of arterial narrowing. Interobserver agreement between the two CTA reviewers for the degree of luminal narrowing was substantial (ĸ = 0.712).CTA was 87% accurate for the diagnosis of large-vessel vasospasm; the NPV of CTA was 95%. CTA was more accurate, and interobserver agreement higher, for the proximal arterial segments (basilar and vertebral arteries) than for the distal ones (P2 segments). Using CTA as a screening modality, 83% of unnecessary DSA would have been avoided. Conclusion: Compared to the gold standard of DSA, CTA is accurate for the detection of large-vessel vasospasm, and has a very high NPV.

Background: The purpose of this study was to compare simple visual grading of perfusion CT (PCT) maps to a more quantitative, threshold-based interpretation of PCT parameters in the characterization of presence and severity of vasospasm. Methods: Thirty-three patients with acute subarachnoid hemorrhage were enrolled in a prospective study and underwent a total of 40 paired PCT and digital subtraction angiography (DSA) examinations. A neuroradiologist and a neurologist reviewed the PCT mean transit time (MTT), cerebral blood flow (CBF), and cerebral blood volume maps independently; they evaluated five anatomical regions (frontal, temporal, parietal, occipital/thalami, and basal ganglia/insula) and graded them for abnormality (0 if normal, 1 if abnormal in <50% of the region, and 2 if abnormal in ≧50% of the region). A third neuroradiologist blinded to the PCT results reviewed the DSA examinations and assessed 19 segments for the presence or absence of vasospasm. Correlation between PCT and DSA scores was assessed, as well as the sensitivity and specificity of PCT compared to DSA used as a gold standard. Results: MTT (R² = 0.939) and CBF (R² = 0.907) scores correlated best with DSA scores (p < 0.001). MTT scoring had a sensitivity of 92% and a specificity of 86% compared to DSA; CBF scoring had a sensitivity of 75% and a specificity of 95%. The interobserver agreement between neuroradiologist and neurologist was found to have kappa = 0.789 for MTT and 0.658 for CBF. Conclusion: We propose a user-friendly visual grading system for PCT maps in patients with suspected vasospasm. This visual approach compares favorably to the results of DSA. Sensitive MTT maps should be used for screening, and specific CBF maps for confirmation of vasospasm.

The purpose of this manuscript is to present two cases of unilateral internal cerebral vein thrombosis (UICVT) and use them to review the typical imaging findings and clinical presentation, provide a differential diagnosis when presented with a unilateral thalamic lesion, and discuss current literature findings of internal cerebral vein thrombosis, including the interesting trend of left-sided involvement. Two cases of UICVT were gathered from our institutions. A literature review was then conducted, and cases in the literature were compared to look for common features. Both of our cases involved the left internal cerebral vein. A total of 7 cases of unilateral and 8 cases of bilateral internal cerebral vein thrombosis were reviewed from the literature. Of the unilateral cases, all but one were on the left, and the one on the right was in a patient with right-sided malignancy after surgical resection. Most of these cases completely resolved with anticoagulation. UICVT is an extremely rare entity, with less than 10 cases reported in the literature. The prognosis of this disease is excellent if diagnosed and treated early; however, with delayed diagnosis and treatment, this process can be fatal. This highlights the importance of keeping this diagnosis on the differential when presented with a unilateral thalamic lesion.