European Radiology

Gu, Jinfeng; Yang, Li; Li, Tao; Liu, Ye; Zhang, Jing; Ning, Kejia; Su, Dajian

doi: 10.1007/s00330-020-07268-9pmid: 32930834

ObjectiveTo determine CT’s role in the early detection of COVID-19 infection and serial CT changes in the disease course in patients with COVID-19 pneumonia.MethodsFrom January 21 to February 18, 2020, all of the patients who were suspected of novel coronavirus infection and verified by RT-PCR tests were retrospectively enrolled in our study. All of the patients underwent serial RT-PCR tests and serial CT imaging. The temporal relationship between the serial RT-PCR results (negative conversion to positive, positive to negative) and serial CT imaging was investigated, and serial CT changes were evaluated.ResultsA total of 155 patients with confirmed COVID-19 pneumonia were evaluated. Chest CT detection time of COVID-19 pneumonia was 2.61 days earlier than RT-PCR test (p = 0.000). The lung CT improvement time was significantly shorter than that of RT-PCR conversion to negative (p = 0.000). Three stages were identified from the onset of the initial symptoms: stage 1 (0–3 days), stage 2 (4–7 days), and stage 3 (8–14 days and later). Ground glass opacity (GGO) was predominant in stage 1, then consolidation and crazy paving signs were dramatically increased in stage 2. In stage 3, fibrotic lesions were rapidly increased. There were significant differences in the main CT features (p = 0.000), number of lobes involved (p = 0.001), and lesion distribution (p = 0.000) among the different stages.ConclusionChest CT detected COVID-19 pneumonia earlier than the RT-PCR results and can be used to monitor disease course. Combining imaging features with epidemiology history and clinical information could facilitate the early diagnosis of COVID-19 pneumonia.Key Points• The chest CT detection time of COVID-19 pneumonia was 2.61 days earlier than that of an initial RT-PCR positive result (t = − 7.31, p = 0.000).• The lung CT improvement time was significantly shorter than that of RT-PCR conversion to negative (t = − 4.72, p = 0.000).• At the early stage (0–3 days), the CT features of COVID-19 were predominantly GGO and small-vessel thickening; at stage 2 (4–7 days), GGO evolved to consolidation and crazy paving signs. At stage 3 (8–14 days and later), fibrotic lesions significantly increased, accompanied by consolidation, GGO, and crazy paving signs.

Blažić, Ivana; Brkljačić, Boris; Frija, Guy

doi: 10.1007/s00330-020-07252-3pmid: 32939620

ObjectivesThis survey conducted by the International Society of Radiology and supported by the European Society of Radiology aimed to collect information regarding radiology departments’ current practices in the management of patients with COVID-19.MethodsResponses from 50 radiology departments involved in the management of COVID-19 patients representing 33 countries across all continents were analyzed. The analysis revealed important variations in imaging practices related to COVID-19 across the world for different disease severity and various clinical scenarios.ResultsImaging is usually not performed in asymptomatic patients (69% of institutions do not image) but is used at the end of confinement (in 60% of institutions). In the majority of institutions, chest imaging is used in suspected or confirmed patients with COVID-19 (89% and 94%). All imaging departments involved in this survey reported the use of imaging in COVID-19 patients showing severe symptoms or who were critically ill. However, there is a wide variation in imaging modality type used for each clinical scenario. The use of imaging is applied in line with existing guidelines and recommendations in 98% of institutions with structured reporting recorded in 58% of institutions. The vast majority of institutions reported a significant impact of the COVID-19 pandemic on the imaging department’s routine activity (83%).ConclusionWe believe that the results of this survey will help to understand current heterogeneities in radiology practice and to identify needs and gaps in the organization and function of radiology departments worldwide in relation to the COVID-19 pandemic. The results of this survey may inform the development of an overall strategy for radiology department organization and imaging protocols in pandemic conditions.Key Points• The results of this survey, which included responses from 50 radiology departments representing 33 countries, showed important variations in imaging practices related to COVID-19 across the world.• While imaging is usually not performed in asymptomatic patients (69% of institutions), it is used in suspected or confirmed patients with COVID-19, in COVID-19 patients showing severe symptoms or who were critically ill, and at the end of confinement (89%, 94%, 100%, 100%, 60% of institutions, respectively). However, there is a wide variation in imaging modality type used for each clinical scenario.• In 98% of institutions, the use of imaging is applied in line with existing guidelines and recommendations, with structured reporting recorded in 58% of institutions. COVID-19 pandemic made a significant impact on the imaging department’s routine activity in 83% of institutions.

Śpiewak, Mateusz; Kłopotowski, Mariusz; Ojrzyńska, Natalia; Petryka-Mazurkiewicz, Joanna; Miłosz-Wieczorek, Barbara; Mazurkiewicz, Łukasz; Grzybowski, Jacek; Bilińska, Zofia; Witkowski, Adam; Marczak, Magdalena

doi: 10.1007/s00330-020-07207-8pmid: 32876838

ObjectivesTo assess the value of cardiac MRI in comparison to echocardiography in consecutive patients with previously diagnosed and new suspected hypertrophic cardiomyopathy (HCM).MethodsAll MRI studies of patients with HCM or suspected disease performed at our centre within a 10-year time period were evaluated. Initial diagnoses (echocardiography-based) and final (MRI-based) diagnoses were compared in subgroups, and the discrepancies were recorded.ResultsA total of 1006 subjects with HCM or suspected HCM were identified (61% males, 39% females; median age, 49.1 years; interquartile range, 34.9–60.4). In 12 (2.2%) out of 550 patients with known HCM, MRI indicated a diagnosis other than HCM, including but not limited to the subaortic membrane (n = 1, 8.3%) or mild left ventricular hypertrophy (n = 5, 41.7%). Among all patients with suspected HCM (n = 456), MRI diagnosis was different from HCM in 5.3% (n = 24) of patients. In an additional 20.4% of patients (n = 93), no significant hypertrophy was present. In total, among patients with suspected HCM, MRI led to clear HCM diagnosis in 204 (44.7%) patients. Among patients with a history of uncontrolled hypertension suspected of having HCM, MRI aided in identifying cardiomyopathy in 47.9% of patients. This subgroup contained the largest proportion of patients with an ambiguous diagnosis, namely, 29.6% compared with 13.8% in the remaining groups of patients with suspected HCM (p = 0.0001).ConclusionsIn a small but important group of patients with ultrasound-based HCM, cardiac MRI can diagnose previously unknown conditions and/or refute suspected cardiomyopathy. The diagnostic yield of MRI when compared to echocardiography in patients suspected of having HCM is 44.7%.Key Points• Out of 550 patients previously diagnosed with echocardiography but without magnetic resonance imaging (MRI) as having hypertrophic cardiomyopathy (HCM), we diagnosed a different disease in 12 (2.2%) patients using MRI.• Among patients with suspected HCM based on echocardiography, MRI led to clear HCM diagnosis in 44.7% of patients.• In patients with a history of uncontrolled hypertension suspected, based on an echocardiogram, of having HCM, MRI aided in identifying cardiomyopathy in 47.9% of patients. This subgroup contained the largest proportion of patients with an ambiguous diagnosis.

Zhao, Peijun; Huang, Lu; Ran, Lingping; Tang, Dazhong; Zhou, Xiaoyue; Xia, Liming

doi: 10.1007/s00330-020-07211-ypmid: 32876836

ObjectivesTo investigate whether cardiovascular magnetic resonance (CMR) T1 mapping and strain parameters can detect early histological and functional myocardial changes in idiopathic inflammatory myopathy (IIM) with negative late gadolinium enhancement (LGE) and preserved ejection fraction.MethodsThirty consecutive patients with IIM (41.5 ± 15.4 years, 24 females) who did not have LGE or reduced left ventricular ejection fraction (LVEF) and 30 age- and gender-matched healthy controls (40.6 ± 14.2 years, 20 females) were recruited. Patients with IIM were further classified into two subgroups according to high-sensitivity cardiac troponin I (hs-cTnI) values: elevated hs-cTnI subgroup (n = 10) and normal hs-cTnI subgroup (n = 20). Myocardial native T1 values, extracellular volume (ECV) fractions, and strain parameters were analyzed in patients with IIM and healthy controls.ResultsCompared with healthy controls, patients with IIM had significantly prolonged native T1 values and increased ECV in each LV segment (p < 0.05). In further subgroup analysis, LV mid-slice native T1 values had the most power to discriminate between patients with elevated hs-cTnI and healthy controls (area under the curve = 0.92). There was no significant difference of global LV strain or strain rates between IIM patients and controls.ConclusionsDiffuse interstitial fibrosis can be detected by CMR T1 mapping in patients with IIM who do not have LGE or reduced LVEF or elevated hs-cTnI, and it may be a promising method for screening subclinical cardiac involvement in IIM.Key Points• Myocardial abnormality in IIM is often subclinical and leads to poor prognosis.• Conventional CMR parameters have limitations in early detection of cardiac function and tissue changes.• CMR T1mapping techniques and myocardial strain analysis have the potential to provide detailed information on cardiac histology and function.

Yu, Yiming; Wang, Yubo; Yang, Maoqing; Huang, Meiping; Li, Jun; Jia, Qianjun; Zhuang, Jian; Huang, Liyu

doi: 10.1007/s00330-020-07238-1pmid: 32885294

ObjectivesA machine learning model was developed to evaluate the severity of aortic coarctation (CoA) in infants based on anatomical features measured on CTA.MethodsIn total, 239 infant patients undergoing both thorax CTA and echocardiography were retrospectively reviewed. The patients were assigned to either mild or severe CoA group based on their pressure gradient on echocardiography. They were further divided into patent ductus arteriosus (PDA) and non-PDA groups. The anatomical features were measured on double-oblique multiplanar reconstructed CTA images. Then, the optimal features were identified by using the Boruta algorithm. Subsequently, the coarctation severity was classified using linear discriminant analysis (LDA). We further investigated the relationship between the anatomical features and re-coarctation using Cox regression.ResultsFour anatomical features showed significant differences between the mild and severe CoA groups, including the smallest aortic cross-sectional area indexed to body surface area (p < 0.001), the narrowest aortic diameter (CoA diameter) indexed to height (p < 0.001), the diameter of the descending aorta at the diaphragmatic level (p < 0.001) and weight (p = 0.005). With these features, accuracy of 88.6% and 90.2%, sensitivity of 65.0% and 72.1%, and specificity of 92.9% and 100% were obtained for classifying the CoA severity in the non-PDA and PDA groups, respectively. Moreover, CoA diameter indexed to weight was associated with the risk of re-coarctation.ConclusionsCoA severity can be evaluated by using LDA with anatomical features. When quantifying the severity of CoA and risk of re-coarctation, both anatomical alternations at the CoA site and the growth of the patients need to be considered.Key Points• CTA is routinely ordered for infants with coarctation of the aorta; however, whether anatomical variations observed with CTA could be used to assess the severity of CoA remains unknown.• Using the diameter and area of the coarctation site adjusted to body growth as features, the LDA model achieved an accuracy of 88.6% and 90.2% in differentiating between the mild and severe CoA patients in the non-PDA group and PDA group, respectively.• The narrowest aortic diameter (CoA diameter) indexed to weight has a hazard ratio of 10.29 for re-coarctation.

Kwan, Alan C.; McElhinney, Priscilla A.; Tamarappoo, Balaji K.; Cadet, Sebastien; Hurtado, Cecilia; Miller, Robert J. H.; Han, Donghee; Otaki, Yuka; Eisenberg, Evann; Ebinger, Joseph E.; Slomka, Piotr J.; Cheng, Victor Y.; Berman, Daniel S.; Dey, Damini

Spagnolo, Pietro; Giglio, Manuela; Di Marco, Daniela; Cannaò, Paola M.; Agricola, Eustachio; Della Bella, Paolo E.; Monti, Caterina B.; Sardanelli, Francesco

doi: 10.1007/s00330-020-07172-2pmid: 32886202

ObjectivesThe current reference standard for diagnosing LAA thrombi is transesophageal echocardiography (TEE), a semi-invasive technique. We aimed to devise an optimal protocol for cardiac computed tomography (CCT) in diagnosing left atrial appendage (LAA) thrombus in patients with atrial fibrillation (AF), using TEE as reference standard.MethodsTwo hundred sixty consecutive patients referred for radiofrequency ablation for AF were prospectively enrolled. All patients underwent CCT and TEE within 2 hours. The CCT protocol included one standard angiographic phase and three delayed acquisitions at 1-, 3-, and 6-min after contrast injection. Thrombi were defined as persisting defects at 6-min delayed acquisition.ResultsTEE demonstrated spontaneous contrast in 52 (20%) patients and thrombus in 10 (4%). In 63 patients (24%), CCT demonstrated LAA early filling defects at angiographic phase. Among them, 15 (6%) had a persistent defect at 1-min, 12 (5%) at 3-min, and 10 (4%) at 6-min. All 10 thrombi diagnosed on TEE were correctly identified by delayed CCT, without any false positives. For all phases, sensitivity and negative predictive were 100%. Specificity increased from 79% for the angiographic phase to 100% at 6-min. Positive predictive value increased from 16% to 100%. Estimated radiation exposure was 2.08 ± 0.76 mSv (mean ± standard deviation) for the angiographic phase and 0.45 ± 0.23 mSv for each delayed phase.ConclusionA CCT protocol adding a 6-min delayed phase to the angiographic phase can be considered optimized for the diagnosis of LAA thrombi, with a low radiation dose.Key Points• In patients with persistent atrial fibrillation referred for ablation procedures, a cardiac CT examination comprising an angiographic-phase acquisition and, in case of filling defects, a 6-min delayed phase may help reduce the need for transesophageal echocardiography.• Cardiac CT would provide morphological and volumetric data, along with the potential to exclude the presence of thrombi in the left atrial appendage.

Pavon, Anna Giulia; Georgiopoulos, Georgios; Vincenti, Gabriella; Muller, Olivier; Monney, Pierre; Berchier, Gregoire; Cirillo, Chiara; Eeckhout, Eric; Schwitter, Juerg; Masci, Pier Giorgio

doi: 10.1007/s00330-020-07254-1pmid: 32929640

ObjectivesT2*-weighted (T2*w) is deemed as a reference standard for post-infarction intramyocardial haemorrhage (IMH). However, high proportion of T2* images is affected by off-resonance artefacts hampering image interpretation. Diagnostic accuracy and precision of alternative techniques for IMH diagnosis and quantification have been seldomly investigated.Methods and resultsBetween April 2016 and May 2017, 50 ST-segment elevation myocardial infarction patients (66% male, 57 ± 17 years) and 15 healthy controls (60% male, 58 ± 13) were consecutively enrolled. Subjects underwent head-to-head comparison of single mid-infarct slice acquired on black-blood T2-weighted short-TI-inversion recovery (T2w-STIR), bright-blood T2prep-steady-state-free precession (T2prep-SSFP), and T2/T1 maps for IMH diagnosis and quantification against T2*w. All images were graded for quality (grade 1: very poor; grade 4: excellent) and diagnostic confidence (Likert scale, 1: very unsure and 5: highly confident). Reduced relaxation time/hypointense region (hypocore) embedded in infarct-related oedema on T2 map, T1 map, and T2w-STIR had the best overall diagnostic accuracy (per-subject: 91%, 86%, and 86%, respectively; per segment: 95%, 93%, and 93%, respectively). By mixed-effects analysis, image quality, and diagnostic confidence were higher for T2 map and T1 maps than T2*w (p < 0.05 for both scores). For IMH quantification, hypocore on T2 map and T1 map strongly correlated (Spearman’s r > 0.7, p < 0.001 for both) with IMH extent on T2*w and presented an overall excellent agreement on Bland-Altman analysis. By linear mixed model analysis, absolute hypocore size did not differ among T1-, T2 map, and T2*w. T2/T1 maps had the best intra- and inter-observer reproducibility among CMR techniques.ConclusionHypocore on T2/T1 map is the best alternative technique to T2*w for diagnosing and quantifying IMH in post-STEMI patients.Key Point• Mapping techniques are the best alternatives for diagnosing post-infarction intramyocardial haemorrhage.• Mapping techniques are valuable tools for imaging intramyocardial haemorrhage.

Cho, Se Jin; Bae, Yun Jung; Kim, Jong-Min; Kim, Donghyun; Baik, Sung Hyun; Sunwoo, Leonard; Choi, Byung Se; Kim, Jae Hyoung

doi: 10.1007/s00330-020-07240-7pmid: 32886201

ObjectiveTo determine the diagnostic performance of neuromelanin-sensitive magnetic resonance imaging discriminating between patients with Parkinson’s disease and normal healthy controls and to identify factors causing heterogeneity influencing the diagnostic performance.MethodsA systematic literature search in the Ovid-MEDLINE and EMBASE databases was performed for studies reporting the relevant topic before February 17, 2020. The pooled sensitivity and specificity values with their 95% confidence intervals were calculated using bivariate random-effects modeling. Subgroup and meta-regression analyses were also performed to determine factors influencing heterogeneity.ResultsTwelve articles including 403 patients with Parkinson’s disease and 298 control participants were included in this systematic review and meta-analysis. Neuromelanin-sensitive magnetic resonance imaging showed a pooled sensitivity of 89% (95% confidence interval, 86–92%) and a pooled specificity of 83% (95% confidence interval, 76–88%). In the subgroup and meta-regression analysis, a disease duration longer than 5 and 10 years, comparisons using measured volumes instead of signal intensities, a slice thickness in terms of magnetic resonance imaging parameters of more than 2 mm, and semi-/automated segmentation methods instead of manual segmentation improved the diagnostic performance.ConclusionNeuromelanin-sensitive magnetic resonance imaging had a favorable diagnostic performance in discriminating patients with Parkinson’s disease from healthy controls. To improve diagnostic accuracy, further investigations directly comparing these heterogeneity-affecting factors and optimizing these parameters are necessary.Key Points• Neuromelanin-sensitive MRI favorably discriminates patients with Parkinson’s disease from healthy controls.• Disease duration, parameters used for comparison, magnetic resonance imaging slice thickness, and segmentation methods affected heterogeneity across the studies.

Conte, Giorgio; Sbaraini, Sara; Morelli, Claudia; Casale, Silvia; Caschera, Luca; Contarino, Valeria Elisa; Scola, Elisa; Cinnante, Claudia; Trogu, Francesca; Triulzi, Fabio; Silani, Vincenzo

doi: 10.1007/s00330-020-07239-0