Resumo Objetivo: Mensurar os tempos de trânsito de contraste (TTCs) entre o sítio de injeção em veia antecubital e a veia cava superior, tronco arterial pulmonar e aorta ascendente em exames de tomografia computadorizada de artérias coronárias de pacientes sem história de doenças cardiovasculares ou pulmonares, definindo padrões de normalidade para esses tempos de circulação. Materiais e Métodos: Os TTCs entre o sítio de injeção e a veia cava superior, tronco arterial pulmonar e aorta ascendente foram medidos com base nas imagens de monitoração (bolus tracking). O débito cardíaco foi calculado com base nas imagens de angiotomografia computadorizada pelo método geométrico e correlacionado com os TTCs. Resultados: Foram analisados 43 pacientes. O TTC médio entre o tronco arterial pulmonar e a aorta ascendente foi de 7,2 s, entre a veia cava superior e o tronco arterial pulmonar foi de 3 s e entre a veia antecubital e a aorta ascendente foi de 13 s. Houve tendência a correlação entre o TTC e o débito cardíaco, com valor de p de 0,055. Conclusão: Os valores de normalidade do TTC entre a veia cava superior, tronco arterial pulmonar e aorta ascendente foram estabelecidos, servindo de base para avaliação clínica.

Abstract Objective: To measure the transit times (TTs) of contrast agents among the injection site (antecubital vein), superior vena cava, pulmonary trunk, and ascending aorta, in coronary computed tomography angiography (CTA) examinations of outpatients with no history of cardiovascular or lung disease, thus defining reference values for those TTs. Materials and Methods: The contrast TTs from the injection site (antecubital vein) to the superior vena cava, from the superior vena cava to the pulmonary trunk, and from the pulmonary trunk to the ascending aorta were measured by monitoring contrast enhancement in real time (bolus tracking). Cardiac output was measured by the geometric method during the CTA examination and was correlated with the contrast TT. Results: Forty-three individuals were analyzed. The mean contrast TT was 13.1 s overall (from the antecubital vein to the ascending aorta), 3.0 s from the superior vena cava to the pulmonary trunk, and 7.2 s from the pulmonary trunk to the ascending aorta. There was a tendency toward a correlation between contrast TT and cardiac output (p = 0.055). Conclusion: The reference values established here for contrast TTs among the superior vena cava, pulmonary trunk, and ascending aorta will serve as a basis for clinical evaluation.

ABSTRACT Objective To describe cerebrovascular manifestations in patients hospitalized for treatment of severe COVID-19, highlighting the comorbidities observed, and those that may play a relevant role as risk factors for severe outcomes. Methods This case series retrospective analyzed, from June to November, 2020, ten patients admitted to the emergency department, with positive nasopharyngeal swab polymerase chain reaction assay for SARS-CoV-2, presenting with neurological symptoms and positive findings at brain imaging studies. Results In this sample, the clinical severity of the symptoms varied from mild to critical. Ischemic stroke was observed in four patients, hemorrhagic events occurred in five cases. Three patients evolved with large parenchymal hemorrhage, and one presented petechial bleeding foci. In one case, we observed subarachnoid hemorrhage associated with bilateral hypodensity in both globus pallidus. Typical posterior reversible encephalopathy syndrome findings were observed in one patient on brain computed tomography. Conclusion Patients with neurovascular complications related to COVID-19 had positive findings in brain imaging and neurological symptoms. The pathological entities observed drew attention to the neurological risk of patients with SARS-CoV-2 infection, including worse outcomes in individuals whose medical history includes clinical comorbidities, especially hypertension and obesity.