Temporal averaging angiographic reconstructions from whole-brain CT perfusion for the detection of vasospasm.

PURPOSE: The aim of this study is to evaluate the image quality and diagnostic performance of angiographic images reconstructed from whole-brain CT perfusion (CTP) using temporal averaging compared to CT angiography (CTA) for the detection of vasospasm. MATERIALS AND METHODS: 39 CT studies in 28 consecutive patients who underwent brain CTA with CTP for suspected vasospasm between September 2020 and May 2021 were retrospectively evaluated. The image quality of these two vascular imaging techniques was assessed either quantitatively (image noise, vascular enhancement, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios,) and qualitatively (4 criteria assessed on a 5-point scale). Intra and interobserver agreements and a diagnostic confidence score on the diagnosis of vasospasm were measured. Radiation dose parameters (volume CT dose index (CTDIvol) and dose-length product (DLP)) were recorded. RESULTS: Both SNR and CNR were significantly higher with temporal averaging compared to CTA, increasing by 104% and 113%, respectively (p<0.001). The qualitative assessment found no significant difference in overall image quality between temporal averaging (4.33 ± 0.48) and brain CTA (4.19 ± 0.52) (p = 0.12).There was a significant improvement in intravascular noise and arterial contrast enhancement with temporal averaging. The evaluation of intra and interobserver agreements showed a robust concordance in the diagnosis of vasospasm between the two techniques. CONCLUSIONS: Temporal averaging appeared as a feasible and reliable imaging technique for the detection of vasospasm. The use of temporal averaging, replacing brain CTA, could represent a new strategy of radiation and contrast material doses reduction in these patients.

Hyperacute simultaneous cardiocerebral infarction related to floating thrombus in the ascending aorta: a case report.

BACKGROUND: Ascending aortic thrombus has been reported in several case reports, often revealed by peripheral embolization, but very few revealed by cardiocerebral infarction. Moreover, there is no defined treatment strategy. CASE SUMMARY: An 83-year-old woman was admitted to our intensive care unit for concurrent acute myocardial infarction (AMI) and acute stroke, both with the presence of an embolism. Imaging revealed a floating thrombus in the ascending aorta. The thrombus resolved after anticoagulant therapy was administered, and there was no subsequent embolism recurrence. DISCUSSION: Floating thrombus in the ascending aorta is an unusual cause of AMI. The main mechanisms of thrombus formation include erosion of an atherosclerotic plaque, but it can also form without tissue abnormality with the probable implication of Virchow's triad. However, the precise mechanism for thrombogenesis remains unknown. In patients with a low surgical risk, we should consider surgical treatment, especially as anticoagulant therapy does not appear to reduce the risk of arterial embolization. Thrombolysis and endovascular interventions have also proven effective in certain cases. Overall, in patients with high surgical risk, decision will have to be made on a case-by-case basis. KEYWORDS: Acute myocardial infarction • Embolic stroke • Coronary embolism • Ascending aorta thrombus • Floating thrombus • Case report.