Middle East Respiratory Syndrome Coronavirus: What Does a Radiologist Need to Know?

OBJECTIVE: The overarching goal of this article is to provide radiologists with the most up-to-date information regarding the underlying epidemiology, pathophysiology, clinical features, and imaging findings related to Middle East respiratory syndrome coronavirus (MERS-CoV), a potentially deadly new infection. CONCLUSION: An increased awareness of MERS-CoV and an understanding of the radiologic features of MERS-CoV can improve the early assessment and monitoring of this new infection. Radiologists can provide information based on chest radiographic and CT scores that can be helpful for patient management and predicting prognosis.

Acute Middle East Respiratory Syndrome Coronavirus: Temporal Lung Changes Observed on the Chest Radiographs of 55 Patients.

OBJECTIVE: The objective of our study was to describe lung changes on serial chest radiographs from patients infected with the acute Middle East respiratory syndrome corona-virus (MERS-CoV) and to compare the chest radiographic findings and final outcomes with those of health care workers (HCWs) infected with the same virus. Chest radiographic scores and comorbidities were also examined as indicators of a fatal outcome to determine their potential prognostic value. MATERIALS AND METHODS: Chest radiographs of 33 patients and 22 HCWs infected with MERS-CoV were examined for radiologic features indicative of disease and for evidence of radiographic deterioration and progression. Chest radiographic scores were estimated after dividing each lung into three zones. The scores (1 [mild] to 4 [severe]) for all six zones per chest radiographic examination were summed to provide a cumulative chest radiographic score (range, 0-24). Serial radiographs were also examined to assess for radiographic deterioration and progression from type 1 (mild) to type 4 (severe) disease. Multivariate logistic regression analysis, Kaplan-Meier survival curve analysis, and the Mann-Whitney U test were used to compare data of deceased patients with those of individuals who recovered to identify prognostic radiographic features. RESULTS: Ground-glass opacity was the most common abnormality (66%) followed by consolidation (18%). Overall mortality was 35% (19/55). Mortality was higher in the patient group (55%, 18/33) than in the HCW group (5%, 1/22). The mean chest radiographic score for deceased patients was significantly higher than that for those who recovered (13 ± 2.6 [SD] vs 5.8 ± 5.6, respectively; p = 0.001); in addition, higher rates of pneumothorax (deceased patients vs patients who recovered, 47% vs 0%; p = 0.001), pleural effusion (63% vs 14%; p = 0.001), and type 4 radiographic progression (63% vs 6%; p = 0.001) were seen in the deceased patients compared with those who recovered. Univariate and logistic regression analyses identified the chest radiographic score as an independent predictor of mortality (odds ratio [OR], 1.38; 95% CI, 1.07-1.77; p = 0.01). The number of comorbidities in the patient group (n = 33) was significantly higher than that in the HCW group (n = 22) (mean number of comorbidities, 1.90 ± 1.27 vs 0.17 ± 0.65, respectively; p = 0.001). The Kaplan-Meier analysis revealed a median survival time of 15 days (95% CI, 4-26 days). CONCLUSION: Ground-glass opacity in a peripheral location was the most common abnormality noted on chest radiographs. A higher chest radiographic score coupled with a high number of medical comorbidities was associated with a poor prognosis and higher mortality in those infected with MERS-CoV. Younger HCWs with few or no comorbidities had a higher survival rate.

CT correlation with outcomes in 15 patients with acute Middle East respiratory syndrome coronavirus.

OBJECTIVE: The purpose of this article is to retrospectively analyze chest CT findings for 15 patients with Middle East respiratory syndrome coronavirus and to identify features associated with survival. MATERIALS AND METHODS: Patients were assigned to group 1 if they died (n=9) and to group 2 if they made a full recovery (n=6). Two reviewers scored chest radiographs and CT examinations for segmental involvement, ground-glass opacities, consolidation, and interstitial thickening. RESULTS: Eight patients had ground-glass opacity (53%), five had ground-glass and consolidation in combination (33%), five had pleural effusion (33%), and four patients had interlobular thickening (27%). Of 281 CT findings, 151 (54%) were peripheral, 68 (24%) were central, and 62 (22%) had a mixed location. The number of involved lung segments was higher in group 1. The lower lobe was more commonly involved (mean, 12.2 segments) than in the upper and middle lobes combined (mean, 6.3 segments). The mean number of lung segments involved was 12.3 segments in group 1 and 3.4 segments in group 2. The CT lung score (mean±SD, 15.78±7.9 vs 7.3±5.7, p=0.003), chest radiographic score (20.8±1.7 vs 5.6±5.4; p=0.001), and mechanical ventilation duration (13.11±8.3 vs 0.5±1.2 days; p=0.002) were higher in group 1. All nine group 1 patients and three of six group 2 patients had pleural effusion (p=0.52). CONCLUSION: CT of patients with Middle East respiratory syndrome coronavirus predominantly showed ground-glass opacities, with peripheral lower lobe preference. Pleural effusion and higher CT lung and chest radiographic scores correlate with poor prognosis and short-term mortality.

Computed tomography virtual bronchoscopy: normal variants, pitfalls, and spectrum of common and rare pathology.

A broad spectrum of pathologies that involve the laryngotracheobronchial airway and imaging plays a crucial role in evaluating these abnormalities. Computed tomography with virtual bronchoscopy has been found to be very helpful in defining the location, extent, and nature of these lesions, and is increasingly being used even in patients with contraindications for fiberoptic bronchoscopy and laryngoscopy. Ionizing radiation, associated with virtual bronchoscopy, can be minimized by using low-dose multidetector computed tomography and hybrid iterative reconstruction techniques. Furthermore, retrospectively generated virtual bronchoscopy from a routinely acquired computed tomography data set eliminates additional cost and radiation. In the future, virtual bronchoscopy assisted with advanced navigational techniques will broaden the diagnostic and therapeutic landscape. This article presents the characteristic features of common and rare laryngotracheobronchial pathologies seen with virtual bronchoscopy.

Williams-Beuren syndrome: computed tomography imaging review.

Williams-Beuren syndrome (WBS) affects young infants and children. The underlying etiopathogenesis of this rare disease is due to the mutation of the elastin gene that is responsible for the elasticity of the arterial wall. As a result of inadequate elastin production, the major systemic arteries become abnormally rigid and can be manifested by an impediment to the blood flow. The most common cardiovascular abnormalities encountered in WBS are supravalvular aortic stenosis, pulmonary arterial stenosis, and mitral valve prolapse. Less frequently observed cardiovascular abnormalities include coarctation of the aorta, ventricular septal defect, patent ductus, subaortic stenosis, and hypertrophic cardiomyopathy. Coronary artery stenosis and severe impediment to the bi-ventricular outflow as a result of supravalvular aortic and pulmonary artery stenosis predispose patients to sudden death. Patients with progressed arterial stenosis and severe stenosis are likely to require intervention to prevent serious complications. Rarely, imaging findings may precede clinical presentation, which allows the radiologist to participate in the patient care. However, to be more prudent, the radiologist must be accustomed to the imaging characteristics of WBS as well as the patient's clinical information, which could raise the suspicion of WBS. We performed a retrospective analysis of all the available images from patients diagnosed with WBS in last 4 years at our institution, and present key imaging findings along with a review of the literature to summarize the clinically relevant features as demonstrated by multidetector computed tomography in WBS. Cross-sectional imaging plays a vital role in the diagnosis of WBS cases with equivocal clinical features. MDCT evaluation of complex cardiovascular abnormalities of WBS including coronary artery disease is feasible with modern MDCT scanners and in the future, this approach could provide accurate information for planning, navigation, and noninvasive assessment of the secondary arterial changes in WBS and thus reducing the dependence upon invasive contrast catherization techniques.

Normative MDCT cross-sectional data estimation of superior vena cava and innominate vein in growing children using age as a predictor.

This retrospective study aimed to determine the superior vena cava (SVC) and left innominate vein (INV) normative cross-sectional area in children noninvasively using age as a predictor and also to compare the correlation of the area measured with the diameter on multidetector computed tomography (MDCT). Analysis of the SVC-INV cross-sectional area was performed for 73 consecutive patients. The cross-sectional area of the SVC-INV was manually estimated. A regression analysis was performed for the cross-sectional area and age separately, and regression equations were compared. One-way analysis of variance (ANOVA) was performed to evaluate significant differences in the area means according to age groups. Regression analysis showed that age can be a predictor for the area of the SVC (50.6 mm(2) + 1.01 × age), te INV (48.3 mm(2) + 0.93 × age), and the left SVC-INV junction (47.2 mm(2) + 0.92 × age), with respective R(2) values of 93, 88 and 94%. The comparative evaluation of the cross-sectional area and the diameter measurement of SVC showed that the cross-sectional area was more closely associated with the increasing age of the cohort (R(2) of 68 vs. 61%) than the measured diameter. For a cohort of patients without congenital or acquired heart disease, MDCT can be used as a complementary test for a normative cross-sectional normogram area database of SVC-INV using age as a predictor.

Follow-up chest radiographic findings in patients with MERS-CoV after recovery.

PURPOSE: To evaluate the follow-up chest radiographic findings in patients with Middle East respiratory syndrome coronavirus (MERS-CoV) who were discharged from the hospital following improved clinical symptoms. MATERIALS AND METHODS: Thirty-six consecutive patients (9 men, 27 women; age range 21-73 years, mean ± SD 42.5 ± 14.5 years) with confirmed MERS-CoV underwent follow-up chest radiographs after recovery from MERS-CoV. The 36 chest radiographs were obtained at 32 to 230 days with a median follow-up of 43 days. The reviewers systemically evaluated the follow-up chest radiographs from 36 patients for lung parenchymal, airway, pleural, hilar and mediastinal abnormalities. Lung parenchyma and airways were assessed for consolidation, ground-glass opacity (GGO), nodular opacity and reticular opacity (i.e., fibrosis). Follow-up chest radiographs were also evaluated for pleural thickening, pleural effusion, pneumothorax and lymphadenopathy. Patients were categorized into two groups: group 1 (no evidence of lung fibrosis) and group 2 (chest radiographic evidence of lung fibrosis) for comparative analysis. Patient demographics, length of ventilations days, number of intensive care unit (ICU) admission days, chest radiographic score, chest radiographic deterioration pattern (Types 1-4) and peak lactate dehydrogenase level were compared between the two groups using the student t-test, Mann-Whitney U test and Fisher's exact test. RESULTS: Follow-up chest radiographs were normal in 23 out of 36 (64%) patients. Among the patients with abnormal chest radiographs (13/36, 36%), the following were found: lung fibrosis in 12 (33%) patients GGO in 2 (5.5%) patients, and pleural thickening in 2 (5.5%) patients. Patients with lung fibrosis had significantly greater number of ICU admission days (19 ± 8.7 days; P value = 0.001), older age (50.6 ± 12.6 years; P value = 0.02), higher chest radiographic scores [10 (0-15.3); P value = 0.04] and higher peak lactate dehydrogenase levels (315-370 U/L; P value = 0.001) when compared to patients without lung fibrosis. CONCLUSION: Lung fibrosis may develop in a substantial number of patients who have recovered from Middle East respiratory syndrome coronavirus (MERS-CoV). Significantly greater number of ICU admission days, older age, higher chest radiographic scores, chest radiographic deterioration patterns and peak lactate dehydrogenase levels were noted in the patients with lung fibrosis on follow-up chest radiographs after recovery from MERS-CoV.