11, Journal of Medical Virology, Vol. Optimizing the utilization of CT pulmonary angiogram (CTPA) for the diagnosis and workup of acute chest pain can provide an opportunity to reduce unnecessary radiation and … Of 2003 patients diagnosed with COVID-19, 280 were hospitalized during the study period. Copyright © 2013-2020, American Roentgen Ray Society, ARRS, All Rights Reserved. 6, 9 July 2020 | Radiology: Cardiothoracic Imaging, Vol. Diagnostic yield of CT pulmonary angiography in the diagnosis of pulmonary embolism: A single center experience Zhonghua Sun1* and Jing Lei2 1Department of Medical Radiation Sciences, Curtin University, Perth, Western Australia, 6845, Australia 2Department of Medical Imaging, First Affiliated Hospital of Kunming Medical The main objective of our study was to evaluate pulmonary embolus in association with COVID-19 infection by using pulmonary CT angiography. The PIOPED II study found that patients with a low or intermediate clinical probability of pulmonary embolism and normal results on CTPA had a high negative predictive value for PE (96% for patients with a low probability and 89% for patients with an intermediate probability); however, the negative predictive value was 60% in patients with a high probability before CTPA. 41, No. The purpose of this article is to describe the techniques to improve motion artifacts, vascular enhancement, flow artifacts, body habitus image noise, vascular opacification in parenchymal lung disease, streak artifacts, and the indeterminate CT pulmonary angiogram. 6, The International Journal of Cardiovascular Imaging, Journal of Molecular Histology, Vol. Furthermore, these patients have frequent risk factors for pulmonary embolus (eg, mechanical ventilation, intensive care unit admission). Retrospective review of 3612 CT pulmonary angiography reports created between … Our study points to a high prevalence of acute pulmonary embolism in patients with coronavirus disease 2019 (23% [95% confidence interval: 15%, 33%]). Acute Pulmonary Embolism in Patients with COVID-19 at CT Angiography and Relationship to d-Dimer Levels Radiology . Using contrast injected into the blood vessels, images are created to look for blockages, aneurysms (dilations of walls), dissections (tearing of walls), and stenosis (narrowing of vessel). It has been suggested that the early detection of acute right ventricular failure allows the implementation of the most appropriate therapeutic strategy . The diagnostic criteria for acute pulmonary embolism include, first, complete arterial occlusion with failure to opacify the entire lumen; the artery may be enlarged in comparison with pulmonary arteries of the same order of branching [31-33] (Fig. 0, 19 November 2020 | Radiology: Cardiothoracic Imaging, Vol. Pulmonary embolism (PE) is a common condition with high mortality and morbidity. Two major issues are related to imaging pulmonary arteries of large patients: image noise and the volume of IV contrast material. Consolidation can cause a focal increase in vascular resistance and focal poor vascular opacification . Occasionally, a large acute central pulmonary embolism can cause oligemia and a reversible decrease in vessel diameter; this CT equivalent of the Westermark sign has been previously illustrated . ); and Nanomedecine Laboratory, INSERM EA4662, University of Franche-Comte, 25000 Besançon, France (S.A., E.D. The injection duration has an important influence in optimizing contrast delivery in CT. Injection of contrast material can be considered in two components: first pass and recirculation. However, the diagnostic and prognostic significance remains unclear. In addition, the protocol is modified to help decrease display image noise and improve scan quality by increasing reconstruction width to 2.5 mm. We acknowledge the preliminary nature of these findings, including its retrospective nature and limited sample size. Upon expiration of these permissions, PMC is granted a perpetual license to make this article available via PMC and Europe PMC, consistent with existing copyright protections. , it is possible to calculate the minimum amount of IV attenuation required to perceive pulmonary emboli on CT. Meaney et al. To comprehensively evaluate for venous thromboembolic disease, patients need to receive a large contrast material bolus to evaluate the lower-limb veins . It followed the ethical guidelines of the Declaration of Helsinki. showed that the detection of a low-contrast abnormality is not accurate when the SD of the mean of the abnormality exceeds the difference in the means of the lesion and the surrounding region . Three authors (F.G., J.B., P.C.) The potential of the noninvasive technique, CT pulmonary angiography (CTPA), has now been realized at most institutions; it has become the test of choice and thus the de facto standard of care . 7, 23 October 2020 | RadioGraphics, Vol. The pleural spaces are clear. At multivariable analysis, pulmonary embolus was associated with invasive mechanical ventilation and male sex. 2, No. COVID-19= coronavirus disease 2019, RT-PCR = reverse-transcription polymerase chain reaction. Interlobular reticulations, bronchiectasis (black arrowhead) and lung architectural distortion are present. Conclusion: Normal CT Pulmonary Angiogram. Sometimes a lesion will be hypovascular compared to the normal tissue and in some cases a lesion will be hypervascular to the surrounding tissue in a certain phase of enhancement. A recent study that evaluated the causes of indeterminate CTPA findings found an indeterminate rate of 6.6% . 4, The American Journal of Cardiology, Vol. A transient interruption of contrast material consists of a portion of the pulmonary artery that shows relatively poor enhancement between areas of higher attenuation both proximally and distally [24, 25] (Fig. Computed tomographic (CT) pulmonary angiography has been evaluated with meta-analysis and has demonstrated sensitivities of 53%–100% and specificities of 83%–100% (, 6), wide ranges that are explained in part by technologic improvements over time.  were among the first to describe pulmonary embolism on contrast-enhanced CT. 32, No. 7, Journal of Proteome Research, Vol. 12. Further imaging may be necessary, either repeating CTPA with an increased delay or pulmonary angiography. The caudal-cranial direction is used because most emboli are located in the lower lobes and, if the patient breathes during image acquisition, there is more excursion of the lower lobes compared with the upper lobes. Streak artifact that obscures pulmonary vessels because of metallic implants can make a study indeterminate, a repeat CT will not improve this problem, and additional imaging with V/Q scintigraphy or pulmonary angiography may be necessary. However, modified window settings can also increase the conspicuity of artifacts caused by image noise and flow. Because the venous return from the inferior vena cava to the right atrium is exaggerated with heightened respiratory movements , we verbally instruct our patients not to perform an exaggerated inspiration and the CT technologist prompts the patient to “hold your breath” before image acquisition. 0, 8 December 2020 | Radiology, Vol. Each radiology department will have a slightly different method for achieving the same outcome, i.e. The sensitivity of V/Q scintigraphy was found to be 98%, with a specificity of 10% . Almost all radiology departments have CT scan 44. It is a unique tool that can visualize disease in the smallest pulmonary vessels, diagnose clinically important coexisting disease, detect the source of thromboembolism, evaluate the deep venous system, and assess the functional sequelae of the embolic event. The pleural spaces are clear. Combining these values with experimental work by Meaney et al. Coronal oblique reformatted image through right posterior basal segmental artery from CT pulmonary angiography shows segment of poor opacification (arrow) between areas of higher attenuation both proximally and distally. See www.arrs.org for more information. A low-density abnormality that simulates pulmonary embolism may result from partial voluming of vessel and lung . 6, International Journal of Infectious Diseases, Vol. Viewer, Table E3, Appendix E1, Pulmonary Embolism and Deep Vein Thrombosis in COVID-19: A Systematic Review and Meta-Analysis, RSNA International Trends: A Global Perspective on the COVID-19 Pandemic and Radiology in Late 2020, Lethal COVID-19: Radiological-Pathological Correlation of the Lungs, Pulmonary COVID-19: Multimodality Imaging Examples, Chest CT in COVID-19: What the Radiologist Needs to Know, Multisystem Imaging Manifestations of COVID-19, Part 1: Viral Pathogenesis and Pulmonary and Vascular System Complications. The first-pass effect is optimized by the use of contrast material with 370 mg I/mL. 12, No. 9, Clinical and Applied Thrombosis/Hemostasis, Vol. Radiology 2005; 237: 329-337. Studies by Schluger et al 13 and Sostman et al 14 found that, in the majority of cases, physicians chose not to perform pulmonary angiography if the V/Q scan was nondiagnostic. A, B, Axial CT images (lung windows) show peripheral ground-glass opacities (arrow in A) associated with areas of consolidation in dependent portions of the lung (white arrowhead). 56, No. Since its introduction in the early 2000s, computed tomographic pulmonary angiography, or CTPA, has been embraced by emergency department and hospital physicians. 50, No. 47, No. CT angiography may provide more precise anatomical details than other angiography exams such as conventional catheter angiography and magnetic resonance imaging (MRI). Interestingly, extent of lesions was not associated with pulmonary embolus. A region-of-interest measurement may be helpful in this decision if the attenuation is greater than 78 H, which is the upper value of acute pulmonary emboli . The solution to transient interruption of contrast flow of the pulmonary arteries is to reduce the volume of unopacified blood entering the right atrium from the inferior vena cava. 12, International Journal of Antimicrobial Agents, Vol. 3, European Journal of Heart Failure, Vol. In 1990, the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study results were published . Our routine protocol for patients with severe clinical features of COVID-19 infection was multidetector pulmonary CT angiography using a 256-slice multidetector CT scanner (Revolution; GE Healthcare, Milwaukee, Wis) after intravenous injection of 60 mL iodinated contrast material (Iomeprol, 400 mg of iodine per milliliter; Bracco Imaging, Milan, Italy) at a flow rate of 4 mL/sec, triggered on the … The greater the right ventricle-to-left ventricle short-axis ratio in acute pulmonary embolism, the greater the risk of death . CT pulmonary angiogram is a medical diagnostic test that employs computed tomography angiography to obtain an image of the pulmonary arteries. The chest CT scan pattern of COVID-19 and presence of pulmonary embolus were independently analyzed by two chest radiologists (J.B. and F.G., with 11 and 6 years of experience, respectively) using a picture archiving and communications system workstation (Carestream Health, Rochester, NY). 9, No. ; and manuscript editing, all authors. 4, Advances in Difference Equations, Vol. Prologo JD, Gilkeson RC, Diaz M, Asaad J.Department of Radiology, University Hospitals of Cleveland, 11100 Euclid Ave., Cleveland, OH 44106. 56, No. What can be done to avoid this flow phenomenon? The pulmonary vasculature may be evaluated with various invasive and noninvasive methods. 1,2 Since the 1990s, CT pulmonary angiography (CTPA) has become the method of choice for imaging in suspected PE. 2A, 2B). There are two principal approaches for performing a CTPA of high diagnostic quality: The CT Coronary Angiogram is a simple procedure without any pain and anxiety . 30, No. Radiology 2005: 235; 1050-1054. After the initial embolic event, the patient may be at risk for circulatory collapse secondary to right heart failure, and a subsequent embolism may be fatal. CT pulmonary angiography (CTPA) is a medical diagnostic test that employs computed tomography to obtain an image of the pulmonary arteries. However, previous reports suggested coagulopathy associated with COVID-19 infection (2,3). Author information: (1)Department of Radiology, Westbury-on-Trym, Bristol, England. 2020 Sep;296(3):E189-E191. A 1990 study showed that pulmonary angiography had a sensitivity of only 87% for PE. This large multicenter trial compared ventilation-perfusion (V/Q) scintigraphy with pulmonary angiography and established the diagnostic characteristics of pulmonary embolism on V/Q scintigraphy. 0, No. A CTPA is performed in the radiology department scanning room, with the patient lying flat (supine) on a CT table. Both acute and chronic pulmonary emboli are identified as intraluminal filling defects that show a sharp interface with IV contrast material. 51, No. Comparisons between categoric variables were performed by using the Pearson χ2 test or Fisher exact test. Ankle Ligaments on MRI: Appearance of Normal and Injured Ligaments, Original Research. No bony abnormality is identified. 8, Revista Española de Anestesiología y Reanimación, Vol. ; clinical studies, F.G., J.B.; statistical analysis, P.C. Oligemia, or a decrease in the flow rate due to acute pulmonary embolism, is often identified on angiography [34, 35]. Twenty-nine patients underwent unenhanced chest CT due to contraindication to iodinated contrast material or nonsevere clinical features; thus, these patients were excluded. In this paper we describe an efficient tool based on natural language processing for classifying the detail state of pulmonary embolism (PE) recorded in CT pulmonary angiography reports. Acta Radiol October 8, 2013 Right ventricular strain or failure is optimally monitored on echocardiography. Pulmonary angiography 1. CONCLUSION. Finally, 100 patients with COVID-19 infection and severe clinical features were included and examined with contrast material–enhanced CT (Fig 1). Patients with unenhanced chest CT scans were excluded. had access to the study data. 4, No. Recognition of this phenomenon is important because the poorly opacified vessel may be normal or the poor contrast enhancement may obscure thrombus. 7, Revista Española de Anestesiología y Reanimación (English Edition), Vol. 40, No. AJR Am J Roentgenol. In 1980, Godwin et al. In cases of discordance, a simultaneous reading to reach consensus was achieved. The requirement for written informed consent was waived. The most robust CT sign is right ventricular dilation (in which the greatest right ventricle short-axis measurement is wider than the maximum left ventricle short-axis measurement)  (Fig. 2A, 2B) and can be a cause of misdiagnosis of pulmonary embolism . CT Angiography for Chest With Contrast (CECT Angiography for Chest ). As the injection duration increases, the recirculation of contrast material causes a cumulative effect on enhancement over time , so that an increase in time increases the enhancement of the pulmonary arteries during the injection. No author has any conflict of interest to declare in relation to this study. AJR Am J Roentgenol. Keywords: chest, CT arteriography, CT technique, embolism. From the Department of Radiology. Computed Tomography (CT) is the mainstay of diagnostic imaging evaluation of thoracic disorders. AJR 2011; 197:1058-1063. 6), a peripheral eccentric filling defect that makes an obtuse angle with the vessel wall [32, 33] (Fig.