Cerebrovascular disease in patients with COVID-19: neuroimaging, histological and clinical description.

Since the appearance of the first case of coronavirus disease 2019 (COVID-19) a pandemic has emerged affecting millions of individuals worldwide. Although the main clinical manifestations are respiratory, an increase in neurological conditions, specifically acute cerebrovascular disease, has been detected. We present cerebrovascular disease case incidence in hospitalized patients with SARS-CoV-2 infection. Patients were confirmed by microbiological/serological testing, or on chest CT semiology. Available data on co-morbidity, laboratory parameters, treatment administered, neuroimaging, neuropathological studies and clinical evolution during hospitalization, measured by the modified Rankin scale, were analysed. A bivariate study was also designed to identify differences between ischaemic and haemorrhagic subtypes. A statistical model of binary logistic regression and sensitivity analysis was designed to study the influence of independent variables over prognosis. In our centre, there were 1683 admissions of patients with COVID-19 over 50 days, of which 23 (1.4%) developed cerebrovascular disease. Within this group of patients, cerebral and chest CT scans were performed in all cases, and MRI in six (26.1%). Histological samples were obtained in 6/23 cases (two brain biopsies, and four arterial thrombi). Seventeen patients were classified as cerebral ischaemia (73.9%, with two arterial dissections), five as intracerebral haemorrhage (21.7%), and one leukoencephalopathy of posterior reversible encephalopathy type. Haemorrhagic patients had higher ferritin levels at the time of stroke (1554.3 versus 519.2, P = 0.004). Ischaemic strokes were unexpectedly frequent in the vertebrobasilar territory (6/17, 35.3%). In the haemorrhagic group, a characteristic radiological pattern was identified showing subarachnoid haemorrhage, parieto-occipital leukoencephalopathy, microbleeds and single or multiple focal haematomas. Brain biopsies performed showed signs of thrombotic microangiopathy and endothelial injury, with no evidence of vasculitis or necrotizing encephalitis. The functional prognosis during the hospital period was unfavourable in 73.9% (17/23 modified Rankin scale 4-6), and age was the main predictive variable (odds ratio = 1.5; 95% confidence interval 1.012-2.225; P = 0.043). Our series shows cerebrovascular disease incidence of 1.4% in patients with COVID-19 with high morbidity and mortality. We describe pathological and radiological data consistent with thrombotic microangiopathy caused by endotheliopathy with a haemorrhagic predisposition.

Early Recurrence Detection of Glioma Using 18 F-Fluorocholine PET/CT : GliReDe Pilot Study.

OBJECTIVE: The aim of this study was to analyze the usefulness of 18 F-fluorocholine PET/CT in the early diagnosis of tumor recurrence, increasing the diagnosis confidence of MRI. METHODS: Patients with a previous gross total resection of glioma and the first suspicious or doubtful for recurrence MRI were prospectively included and subjected to 18 F-fluorocholine PET/CT. An independent and combined assessment of 18 F-fluorocholine PET/CT and multimodal MRI was performed classifying the studies as positive or negative for tumor recurrence. Final diagnosis (recurrence or not) was obtained by histological confirmation or clinical and imaging follow-up. The relation of SUV max and tumor-to-background ratio with progression, the diagnostic performance of imaging techniques, and their concordance (κ Cohen) were analyzed. RESULTS: Twenty-four studies on 21 patients were assessed. Recurrence was diagnosed in 20 cases. PET/CT was positive in 23 cases (3 false positive), whereas MRI was positive in 15 cases (1 false positive). MRI was false negative in 6 cases. There was no false negative on 18 F-fluorocholine PET/CT. Accuracy of PET/CT versus MRI was 87.5% and 70.8%, respectively. The combined evaluation of both techniques did not show any advantage with respect to PET/CT results alone. The concordance between both imaging techniques was low (κ = 0.135; P = 0.375). SUV max and tumor-to-background ratio were related to recurrence (areas under the curve of 0.844 [ P = 0.033] and 0.869 [ P = 0.022], respectively). CONCLUSIONS: 18 F-fluorocholine PET/CT was helpful for increasing the diagnostic confidence in the cases of MRI doubtful for recurrence in order to avoid a delayed diagnosis.

FuMeGA Criteria for Visual Assessment of Postoperative 18F-Fluorocholine PET in Patients With Glioma.

Postoperative assessment is crucial in the imaging follow-up and prognosis in patients with glioma. Whereas grade of resection is defined attending to the gadolinium enhancement in early postoperative MRI, no metabolical criteria exist for postoperative PET interpretation. Based on our prospective and multicenter FuMeGA (Functional and Metabolic Glioma Analysis) ongoing study, we propose criteria for the visual interpretation of F-fluorocholine PET scans in patients undergoing brain tumor resection. The different imaging characteristics between MRI and PET may explain the discordances regarding to the postresection status with both techniques.

18F-Fluorocholine PET/CT in the Prediction of Molecular Subtypes and Prognosis for Gliomas.

AIM: To study the association of metabolic features of F-fluorocholine in gliomas with histopathological and molecular parameters, progression-free survival (PFS) and overall survival (OS). METHODS: Prospective multicenter and nonrandomized study (Functional and Metabolic Glioma Analysis). Patients underwent a basal F-fluorocholine PET/CT and were included after histological confirmation of glioma. Histological and molecular profile was assessed: grade, Ki-67, isocitrate dehydrogenase status and 1p/19q codeletion. Patients underwent standard treatment after surgery or biopsy, depending on their clinical situation. Overall survival and PFS were obtained after follow-up. After tumor segmentation of PET images, SUV and volume-based variables, sphericity, surface, coefficient of variation, and multilesionality were obtained. Relations of metabolic variables with histological, molecular profile and prognosis were evaluated using Pearson χ and t test. Receiver operator caracteristic curves were used to obtain the cutoff of PET variables. Survival analysis was performed using Kaplan-Meier and Cox regression analysis. RESULTS: Forty-five patients were assessed; 38 were diagnosed as having high-grade gliomas. Significant differences of SUV-based variables with isocitrate dehydrogenase status, tumor grade, and Ki-67 were found. Tumor grade, Ki-67, SUVmax, and SUVmean were related to progression. Kaplan-Meier analysis revealed significant associations of SUVmax, SUVmean, and multilesionaly with OS and PFS. SUVmean, sphericity, and multilesionality were independent predictors of OS and PFS in Cox regression analysis. CONCLUSIONS: Metabolic information obtained from F-fluorocholine PET of patients with glioma may be useful in the prediction of tumor biology and patient prognosis.