18F-FDG PET/CT在新型冠状病毒肺炎诊断中的应用

新型冠状病毒肺炎（COVID-19）被发现以来,迅速蔓延,其早期诊断有利于患者的及时救治和疾病进一步传播的有效控制。目前,诊断的依据是流行病史、临床表现、影像学特征和逆转录聚合酶链式反应（RT-PCR）检测结果,其中RT-PCR检测到新型冠状病毒核酸阳性是COVID-19确诊的主要依据,影像学特征尤其是肺部高分辨率CT表现则是诊断该病的重要临床依据。作为一种被广泛应用的影像学方法,18F-FDG PET/CT在COVID-19中的价值仍未可知。笔者分析了18F-FDG PET/CT在COVID-19中的诊断和鉴别诊断的价值,以及评估COVID-19患者纵隔淋巴结受累情况方面的潜在应用,讨论了COVID-19患者肺外器官和组织受累可能出现的18F-FDG PET/CT影像学表现。     

Magnetic resonance imaging features of coronavirus disease 2019 (COVID-19) pneumonia: The first preliminary case series

Rationale and objectivesThere is a rising onus on understanding the common features of COVID-19 pneumonia on different imaging modalities. In this study, we aimed to review and depict the common MRI features of COVID-19 pneumonia in our laboratory confirmed case series, the first comprehensive reported cohort in the literature.Materials and methodsUpon IRB approval, eight laboratory confirmed COVID-19 patients who presented to our outpatient imaging clinic underwent chest CT and, once various features of COVID-19 pneumonia were identified, a dedicated multisequence chest MRI was performed on the same day with an institutional protocol. Demographic data and the morphology, laterality and location of the lesions were recorded for each case.ResultsFive males and three females with the mean age of 40.63 ± 12.64 years old were present in this case series. Five cases had typical CT features with ground glass opacities and consolidations, readily visible on different MRI sequences. Three cases had indeterminate or atypical features which were also easily seen on MRI. The comprehensive review of MRI features for each case and representative images have been illustrated.ConclusionBecoming familiar with typical findings of COVID-19 pneumonia in MRI is crucial for every radiologist. Although MRI is not the modality of choice for evaluation of pulmonary opacities, it has similar capabilities in detection of COVID-19 pneumonia when compared to chest CT.     

Evaluating current chest imaging practices of pediatric patients with COVID-19: A retrospective analysis

PurposeThis retrospective analysis aims to examine the effectiveness of the current chest imaging guidelines regarding COVID-19 positive pediatric patients on our study group of patients aged 0 to 18.Materials and methodsWe examined clinical and imaging data of 178 pediatric COVID-19 positive patients confirmed by PCR admitted to the Children's Hospital of Los Angeles between March 6, 2020 and June 23, 2020.ResultsOf 178 patients, only 46 (27%) patients underwent any form of chest imaging. Thirteen (28%) of 46 imaged patients had positive chest X-rays (CXR) or computed tomography (CT) chest findings, with 8 (62%) of the 13 patients suggesting pneumonia or multifocal pneumonia, 3 (23%) patients having acute respiratory distress syndrome, and 2 (15%) patients demonstrating left sided pleural effusions thought to be the result of ruptured appendicitis unrelated to their COVID-19 diagnosis. All but one patient had significant prior medical histories with an associated comorbid medical condition. Of the 46 imaged patients, 17 (37%) patients had a negative chest X-ray, and 15 (33%) patients had suggestive findings of viral etiology. 132 patients were not imaged.ConclusionOur study population corroborated current chest imaging guidelines in pediatric patients. Chest imaging modalities such as CXR and CT should be reserved for patients who are severely symptomatic and/or possess prior comorbidities such as immunosuppression, diabetes, asthma, obesity, or where other differential etiologies must be entertained.     

Systematic review and meta-analysis of chest radiograph (CXR) findings in COVID-19

Chest radiography (CXR) is most likely to be the utilized modality for diagnosing COVID-19 and following up on any lung-associated abnormalities. This review provides a meta-analysis of the current literature on CXR imaging findings to determine the most common appearances of lung abnormalities in COVID-19 patients in order to equip medical researchers and healthcare professionals in their efforts to combat this pandemic. Twelve studies met the inclusion criteria and were analyzed. The inclusion criteria consisted of: (1) published in English literature; (2) original research study; (3) sample size of at least 5 patients; (4) reporting clinical characteristics of COVID-19 patients as well as CXR imaging features; and (5) noting the number of patients with each corresponding imaging feature. A total of 1948 patients were included in this study. To perform the meta-analysis, a random-effects model calculated the pooled prevalence and 95% confidence intervals of abnormal CXR imaging findings. Seventy-four percent (74%) (95% CI: 51–92%) of patients with COVID-19 had an abnormal CXR at the initial time of diagnosis or sometime during the disease course. While there was no single feature on CXR that was diagnostic of COVID-19 viral pneumonia, a characteristic set of findings were obvious. The most common abnormalities were consolidation (28%, 95% CI: 8–54%) and ground-glass opacities (29%, 95% CI: 10–53%). The distribution was most frequently bilateral (43%, 95% CI: 27–60%), peripheral (51%, 95% CI: 36–66%), and basal zone (56%, 95% CI: 37–74%) predominant. Contrary to parenchymal abnormalities, pneumothorax (1%, 95% CI: 0–3%) and pleural effusions (6%, 95% CI: 1–16%) were rare.     

Diagnostic accuracy of thoracic imaging modalities for the detection of COVID-19

The ongoing coronavirus disease 2019 (COVID-19) pandemic continues to present diagnostic challenges. The use of thoracic radiography has been studied as a method to improve the diagnostic accuracy of COVID-19. The ‘Living’ Cochrane Systematic Review on the diagnostic accuracy of imaging tests for COVID-19 is continuously updated as new information becomes available for study. In the most recent version, published in March 2021, a meta-analysis was done to determine the pooled sensitivity and specificity of chest X-ray (CXR) and lung ultrasound (LUS) for the diagnosis of COVID-19. CXR gave a sensitivity of 80.6% (95%CI: 69.1-88.6) and a specificity of 71.5% (95%CI: 59.8-80.8). LUS gave a sensitivity rate of 86.4% (95%CI: 72.7-93.9) and specificity of 54.6% (95%CI: 35.3-72.6). These results differed from the findings reported in the recent article in this journal where they cited the previous versions of the study in which a meta-analysis for CXR and LUS could not be performed. Additionally, the article states that COVID-19 could not be distinguished, using chest computed tomography (CT), from other respiratory diseases. However, the latest review version identifies chest CT as having a specificity of 80.0% (95%CI: 74.9-84.3), which is much higher than the previous version which indicated a specificity of 61.1% (95%CI: 42.3-77.1). Therefore, CXR, chest CT and LUS have the potential to be used in conjunction with other methods in the diagnosis of COVID-19.     

Imaging of Coronavirus Disease 2019 Infection From Head to Toe: A Primer for the Radiologist

Coronavirus Disease 2019 (COVID-19) disease has rapidly spread around the world after initial identification in Wuhan, China, in December 2019. Most common presentation is mild or asymptomatic disease, followed by pneumonia, and rarely- multiorgan failure and Acute Respiratory Distress Syndrome (ARDS). Knowledge about the pathophysiology, imaging and treatment of this novel virus is rapidly evolving due to ongoing worldwide research. Most common imaging modalities utilized during this pandemic are chest radiography and HRCT with findings of bilateral peripheral, mid and lower zone GGO and/or consolidation, vascular enlargement and crazy paving. HRCT is also useful for prognostication and follow-up of severely ill COVID-19 patients. Portable radiography allows follow-up of ICU patients & obviates the need of shifting critically ill patients and disinfection of CT room. As the pandemic has progressed, numerous neurologic manifestations have been described in COVID-19 including stroke, white matter hyperintensities and demyelination on MRI. Varying abdominal presentations have been described, which on imaging either show evidence of COVID-19 pneumonia in lung bases or show abdominal findings including bowel thickening and vascular thrombosis. Numerous thrombo-embolic and cardiovascular complications have also been described in COVID-19 including arterial and venous thrombosis, pulmonary embolism and myocarditis. It is imperative for radiologists to be aware of all the varied faces of this disease on imaging, as they may well be the first physician to suspect the disease. This article aims to review the multimodality imaging manifestations of COVID-19 disease in various organ systems from head to toe.     

Chest radiological finding of COVID-19 in patients with and without diabetes mellitus: Differences in imaging finding

The pandemic of novel coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Diabetes mellitus is a risk factor for developing severe illness and a leading cause of death in patients with COVID-19. Diabetes can precipitate hyperglycaemic emergencies and cause prolonged hospital admissions. Insulin resistance is thought to cause endothelial dysfunction, alveolar capillary micro-angiopathy and interstitial lung fibrosis through pro-inflammatory pathways. Autopsy studies have also demonstrated the presence of microvascular thrombi in affected sections of lung, which may be associated with diabetes. Chest imaging using x-ray (CXR) and computed tomography (CT) of chest is used to diagnose, assess disease progression and severity in COVID-19. This article reviews current literature regarding chest imaging findings in patients with diabetes affected by COVID-19. A literature search was performed on PubMed. Patients with diabetes infected with SARS-CoV-2 are likely to have more severe infective changes on CXR and CT chest imaging. Severity of airspace consolidation on CXR is associated with higher mortality, particularly in the presence of co-morbidities such as ischaemic heart disease. Poorly controlled diabetes is associated with more severe acute lung injury on CT. However, no association has been identified between poorly-controlled diabetes and the incidence of pulmonary thromboembolism in patients with COVID-19.     

Comparative evaluation of chest radiography,low-field MRI,the Shwachman-Kulczycki score and pulmonary function tests in patients with cystic fibrosis

The aim of this study was to investigate whether the parenchymal lung damage in patients suffering from cystic fibrosis (CF) can be equivalently quantified by the Chrispin-Norman (CN) scores determined with low-field magnetic resonance imaging (MRI) and conventional chest radiography (CXR). Both scores were correlated with pulmonary function tests (PFT) and the Shwachman-Kulczycki method (SKM). To evaluate the comparability of MRI and CXR for different states of the disease, all scores were applied to patients divided into three age groups. Seventy-three CF patients (mean SKM score: 62 ± 8) with a median age (range) of 14 years (7–32) were included. The mean CN scores determined with both imaging methods were comparable (CXR: 12.1 ± 4.7; MRI: 12.0 ± 4.5) and showed high correlation (P < 0.05, R = 0.97). Only weak correlations were found between imaging, PFT, and SKM. Both imaging modalities revealed significantly more severe disease expression with age, while PFT and SKM failed to detect early signs of disease. We conclude that imaging of the lung in CF patients is capable of detecting subtle and early parenchymal destruction before lung function or clinical scoring is affected. Furthermore, low-field MRI revealed high consistency with chest radiography and may be used for a thorough follow-up while avoiding radiation exposure.     

Incidental radiological findings suggestive of COVID-19 in asymptomatic patients

Despite routine screening of patients for coronavirus disease 2019 (COVID-19) symptoms and signs at hospital entrances, patients may slip between the cracks and be incidentally discovered to have lung findings that could indicate COVID-19 infection on imaging obtained for other reasons. Multiple case reports and case series have been published to identify the pattern of this highly infectious disease. This article addresses the radiographic findings in different imaging modalities that may be incidentally seen in asymptomatic patients who carry COVID-19. In general, findings of COVID-19 infection may appear in computed tomography (CT), magnetic resonance imaging, positron emission tomography-CT, ultrasound, or plain X-rays that show lung or only apical or basal cuts. The identification of these characteristics by radiologists and clinicians is crucial because this would help in the early recognition of cases so that a rapid treatment protocol can be established, the immediate isolation to reduce community transmission, and the organization of close monitoring. Thus, it is important to both the patient and the physician that these findings are highlighted and reported.     

Neuroimaging Findings in Patients with COVID-19: A Systematic Review and Meta-Analysis

ObjectiveCentral nervous system involvement in coronavirus disease 2019 (COVID-19) has been increasingly reported. We performed a systematic review and meta-analysis to evaluate the incidence of radiologically demonstrated neurologic complications and detailed neuroimaging findings associated with COVID-19.Materials and MethodsA systematic literature search of MEDLINE/PubMed and EMBASE databases was performed up to September 17, 2020, and studies evaluating neuroimaging findings of COVID-19 using brain CT or MRI were included. Several cohort-based outcomes, including the proportion of patients with abnormal neuroimaging findings related to COVID-19 were evaluated. The proportion of patients showing specific neuroimaging findings was also assessed. Subgroup analyses were also conducted focusing on critically ill COVID-19 patients and results from studies that used MRI as the only imaging modality.ResultsA total of 1394 COVID-19 patients who underwent neuroimaging from 17 studies were included; among them, 3.4% of the patients demonstrated COVID-19-related neuroimaging findings. Olfactory bulb abnormalities were the most commonly observed (23.1%). The predominant cerebral neuroimaging finding was white matter abnormality (17.6%), followed by acute/subacute ischemic infarction (16.0%), and encephalopathy (13.0%). Significantly more critically ill patients had COVID-19-related neuroimaging findings than other patients (9.1% vs. 1.6%; p = 0.029). The type of imaging modality used did not significantly affect the proportion of COVID-19-related neuroimaging findings.ConclusionAbnormal neuroimaging findings were occasionally observed in COVID-19 patients. Olfactory bulb abnormalities were the most commonly observed finding. Critically ill patients showed abnormal neuroimaging findings more frequently than the other patient groups. White matter abnormalities, ischemic infarctions, and encephalopathies were the common cerebral neuroimaging findings.     

Proton MRI appearance of cystic fibrosis: Comparison to CT

Cystic fibrosis (CF) is the most frequent inherited disorder leading to premature death in the Caucasian population. As life expectancy is limited by pulmonary complications, repeated imaging [chest X-ray, multislice high-resolution computed tomography (MS-HRCT)] is required in the follow-up. Magnetic resonance imaging (MRI) of the lung parenchyma is a promising new diagnostic tool. Its value for imaging lung changes caused by CF compared with CT is demonstrated. MRI performs well when compared with CT, which serves as the gold standard. Its lack in spatial resolution is obvious, but advantages in contrast and functional assessment compensate for this limitation. Thus, MRI is a reasonable alternative for imaging the CF lung and should be introduced as a radiation-free modality for follow-up studies in CF patients. For further evaluation of the impact of MRI, systematic studies comparing MRI and conventional imaging modalities are necessary. Furthermore, the value of the additional functional MRI (fMRI) information has to be studied, and a scoring system for the morphological and functional aspect of MRI has to be established. This work was supported by the “Forschungsgemeinschaft Mukoviszidose” (S06/04).     

Role of cardiac magnetic resonance imaging in the diagnosis and management of COVID-19 related myocarditis: Clinical and imaging considerations

There is a growing evidence of cardiovascular complications in coronavirus disease 2019 (COVID-19) patients. As evidence accumulated of COVID-19 mediated inflammatory effects on the myocardium, substantial attention has been directed towards cardiovascular imaging modalities that facilitate this diagnosis. Cardiac magnetic resonance imaging (CMRI) is the gold standard for the detection of structural and functional myocardial alterations and its role in identifying patients with COVID-19 mediated cardiac injury is growing. Despite its utility in the diagnosis of myocardial injury in this population, CMRI’s impact on patient management is still evolving. This review provides a framework for the use of CMRI in diagnosis and management of COVID-19 patients from the perspective of a cardiologist. We review the role of CMRI in the management of both the acutely and remotely COVID-19 infected patient. We discuss patient selection for this imaging modality; T1, T2, and late gadolinium enhancement imaging techniques; and previously described CMRI findings in other cardiomyopathies with potential implications in COVID-19 recovered patients.