Comparing magnetic resonance angiography (MRA) and computed tomography angiography (CTA) with conventional angiography in the detection of distal territory cerebral mycotic and oncotic aneurysms

Background Mycotic and oncotic aneurysms may result in devastating neurologic sequelae if undetected. The objectives of this study were to examine interobserver variability and accuracy of cross-sectional imaging for the detection of distal territory mycotic and oncotic aneurysms. Methods We searched our institutional database for all radiology reports from 2005 to 2015 with an indication or diagnosis of mycotic or oncotic aneurysm. Patients who underwent DSA and either CTA or MRA within 12 weeks of each other were identified. The cross-sectional images from each study were blinded and reviewed by two radiologists. If positive for aneurysm, location and number of aneurysms were reported. Sensitivity, specificity, positive predictive value, negative predictive value, and interobserver variability were determined for MRA and MRA/CTA. Results Twenty-five patients were included in this study. Ten (40%) harbored distal aneurysms. Cross-sectional imaging had a sensitivity of 45.5%, specificity of 90.0%, and kappa value of 0.29 (0.00–0.69) for the detection of cerebral mycotic and oncotic aneurysms. Conclusions Because of the low sensitivity and high interobserver variability of cross-sectional imaging, DSA should remain the gold standard for evaluation of suspected oncotic and mycotic aneurysms. In cases in which cross sectional imaging is negative and there is a high clinical suspicion for mycotic aneurysm, DSA should be strongly considered.

Neuroimaging Findings in Cardiac Myxoma Patients: A Single-Center Case Series of 47 Patients

Background and Purpose: Cardiac myxomas can present with a myriad of neurological complications including stroke, cerebral aneurysm formation and metastatic disease. Our study had two objectives: (1) to describe the neuroimaging findings of patients with cardiac myxomas and (2) to examine the relationship between a history of embolic complications secondary to myxoma and intracranial aneurysm formation, hemorrhage and metastatic disease. We hypothesized that patients who present with embolic complications related to myxoma would be more likely to have such complications. Materials and Methods: We searched our institutional database for all patients with pathologically proven cardiac myxomas from 1995 to 2014 who received neuroimaging. Neuroimaging findings were categorized as acute ischemic stroke, intracerebral hemorrhage, oncotic aneurysm, and cerebral metastasis. Cardiac myxoma patients were divided into those presenting with embolic complications (i.e. lower extremity emboli or cerebral emboli) and those presenting with non-embolic complications prior to surgical resection of the myxoma. The prevalence of intracranial hemorrhage, myxomatous aneurysm formation, and cerebral metastases was compared in myxoma patients presenting with and without embolic complications using a Chi-squared test. Results: Forty-seven consecutive patients were included in this study. Sixteen patients (34.0%) had imaging evidence of acute ischemic stroke. Of these, 13 had acute ischemic strokes directly attributed to the cardiac myxoma (27.7%) and 3 had acute ischemic strokes secondary to causes other than myxoma (6.4%). Seven patients (14.9%) had aneurysms. Two patients (4.3%) had parenchymal metastatic disease on long-term imaging. Fourteen patients (29.8%) presented with ischemic symptoms that were attributed to cardiac myxoma (1 with lower extremity ischemia, 1 with lower extremity ischemia and ischemic stroke, and 12 with ischemic stroke). Patients presenting with embolic complications related to the myxoma (ischemic stroke or lower extremity ischemia) were more likely to have imaging evidence of intracranial hemorrhage (21.4 vs. 3.0%, p = 0.09), oncotic aneurysm (35.7 vs. 6.1%, p = 0.03), and cerebral metastasis (14.3 vs. 0.0%, p = 0.07) on follow-up imaging. Conclusions: Ischemic stroke and intracranial oncotic aneurysm were found in a substantial proportion of cardiac myxoma patients undergoing neuroimaging. Patients presenting with embolic complications of cardiac myxoma are more likely to have intracranial hemorrhage, intracranial oncotic aneurysms, and cerebral metastatic disease.

Oncotic aneurysm

✓ The author describes a case of intracerebral and subarachnoid hemorrhage associated with an intracranial aneurysm caused by a metastatic tumor. The aneurysm formation is explained as being a result of tumor cells invading the vessel wall while still preserving the arterial circulation.