Radiological Imaging of Viral Pneumonia Cases Identified Before the COVID-19 Pandemic Period and COVID-19 Pneumonia Cases Comparison of Characteristics

BackgroundThoracic CT imaging is widely used as a diagnostic method in the diagnosis of COVID-19 pneumonia. Radiological differential diagnosis and isolation of other viral agents causing pneumonia in patients gained importance, especially during the pandemic period. AimsWe aimed to investigate whether there is a difference between the CT imaging findings characteristically defined in COVID-19 pneumonia and the findings detected in pneumonia due to other viral agents, and which finding may be more effective in the diagnosis. Study DesignThe study included 249 adult patients with pneumonia found in thorax CT examination and positive COVID-19 RT-PCR test and 94 patients diagnosed with non-COVID pneumonia (viral PCR positive, no bacterial/fungal agents were detected in other cultures) from the last 5 years before the pandemic. It was retrospectively analyzed using the PACS System. CT findings were evaluated by two radiologists with 5 and 20 years of experience who did not know to which group the patient belonged, and it was decided by consensus. MethodsDemographic data (age, gender, known chronic disease) and CT imaging findings (percentage of involvement, number of lesions, distribution preference, dominant pattern, ground-glass opacity distribution pattern, nodule, tree in bud sign, interstitial changes, crazy paving sign, reversed halo sign, vacuolar sign, halo sign, vascular enlargement, linear opacities, traction bronchiectasis, peribronchial wall thickness, air trapping, pleural retraction, pleural effusion, pericardial effusion, cavitation, mediastinal/hilar lymphadenopathy, dominant lesion size, consolidation, subpleural curvilinear opacities, air bronchogram, pleural thickening) of the patients were evaluated. CT findings were also evaluated with the RSNA consensus guideline and the CORADS scoring system. Data were divided into two main groups as non-COVID-19 and COVID-19 pneumonia and compared statistically with chi-square tests and multiple regression analysis of independent variables. ResultsTwo main groups; RSNA and CORADS classification, percentage of involvement, number of lesions, distribution preference, dominant pattern, nodule, tree in bud, interstitial changes, crazy paving, reverse halo vascular enlargement, peribronchial wall thickness, air trapping, pleural retraction, pleural/pericardial effusion, cavitation and mediastinal/hilar lymphadenopathy were compared, significant differences were found between the groups (p < 0.01). Multiple linear regression analysis of independent variables found a significant effect of reverse halo sign ({beta} = 0.097, p <0.05) and pleural effusion ({beta} = 10.631, p <0.05) on COVID-19 pneumonia. ConclusionPresence of reverse halo and absence of pleural effusion was found to be efficient in the diagnosis of COVID-19 pneumonia.

Behavior of hepatocellular adenoma on real-time low-mechanical index contrast-enhanced ultrasonography with a second-generation contrast agent.

OBJECTIVE: The purpose of this study was to describe the behavior of histologically proven hepatocellular adenoma (HCA) on low-mechanical index (MI) contrast-enhanced ultrasonography (CEUS). METHODS: A review of the databases from 4 academic hospitals revealed 18 patients (15 female and 3 male; mean age, 40 years; range, 25-71 years) with 25 histologically proven HCA lesions who were studied with CEUS at a low MI (0.04-0.1). RESULTS: Twenty-four of 25 lesions (96%; 95% confidence interval [CI], 80.5%-99.3%) showed high-intensity enhancement, scored as 3 on a scale of 0 to 3, whereas only 1 lesion (4%; 95% CI, 0.7%-19.5%) was scored as 2. The time of peak enhancement ranged between 10 and 19 seconds (average, 13 seconds). All but 1 of the 25 lesions (96%; 95% CI, 80.5%-99.3%) showed early homogeneous and centripetal enhancement during the hepatic arterial phase. No portal venous phase enhancement was observed in any lesion because all showed rapid wash-out (100%; 95% CI, 86.7%-100%). Twenty lesions (80%; 95% CI, 60.9%-91.1%) were found to be isoechoic to slightly hypoechoic during the portal phase, and 19 (76%; 95% CI, 56.6%-88.5%) were isoechoic to mildly hypoechoic, whereas 7 (24%; 95% CI, 11.5%-43.4%) were hypoechoic during the late phase. CONCLUSIONS: Contrast-enhanced ultrasonography is an effective technique for identifying the microvascular and macrovascular characteristics of HCA. Typically, HCA shows early (10-19 seconds) and centripetal enhancement during the arterial phase and isoechogenicity or mild hypoechogenicity during the portal phase, remaining slightly hypoechoic or isoechoic during the late phase in most cases.

Pancreatic adenocarcinoma: MDCT versus MRI in the detection and assessment of locoregional extension.

PURPOSE: To compare dynamic-contrast enhanced multirow detector computed tomography (MDCT) including multiplanar reformatted images (MPR) and magnetic resonance imaging (MRI) including magnetic resonance cholangiopancreatography images for the detection and assessment of locoregional extension of pancreatic adenocarcinoma. MATERIALS AND METHODS: Twenty-four patients with and 21 patients without pancreatic adenocarcinoma underwent triple-phase MDCT and MRI. Three radiologists independently attempted to detect pancreatic adenocarcinoma and assess locoregional extension in 3 sessions. First session involved MDCT images. In the second session, radiologists had access to coronal and sagittal MPR images together with the axial images (MDCT + MPR). Third session involved MR images. Results were compared with surgical findings using receiver operating characteristic analysis and kappa statistics. RESULTS: Regarding tumor detection, MDCT + MPR had a significantly higher value for areas under the curve (0.96 +/- 0.02) at receiver operating characteristic analysis compared with those of MRI (0.90 +/- 0.03) and MDCT (0.85 +/- 0.04). MDCT + MPR had the highest mean sensitivity (96%), and MRI had the highest mean specificity (98%). For locoregional extension, MDCT + MPR showed the highest kappa values of the study for all factors evaluated (range, 0.63-0.86). CONCLUSIONS: In conclusion, multiphasic MDCT imaging with MPR images was superior to multiphasic MDCT imaging without MPR images and to comprehensive MRI employing 2-D sequences and magnetic resonance cholangiopancreatography for both the detection and assessment of locoregional extension of pancreatic adenocarcinomas. MRI might be used for further lesion characterization regarding its high specificity.