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To investigate the performance of a joint convolutional neural networks-recurrent neural networks (CNN-RNN) using an attention mechanism in identifying and classifying intracranial hemorrhage (ICH) on a large multi-center dataset; to test its performance in a prospective independent sample consisting of consecutive real-world patients. All consecutive patients who underwent emergency non-contrast-enhanced head CT in five different centers were retrospectively gathered. Five neuroradiologists created the ground-truth labels. The development dataset was divided into the training and validation set. After the development phase, we integrated the deep learning model into an independent center's PACS environment for over six months for assessing the performance in a real clinical setting. Three radiologists created the ground-truth labels of the testing set with a majority voting. A total of 55,179 head CT scans of 48,070 patients, 28,253 men (58.77%), with a mean age of 53.84 ± 17.64 years (range 18–89) were enrolled in the study. The validation sample comprised 5211 head CT scans, with 991 being annotated as ICH-positive. The model's binary accuracy, sensitivity, and specificity on the validation set were 99.41%, 99.70%, and 98.91, respectively. During the prospective implementation, the model yielded an accuracy of 96.02% on 452 head CT scans with an average prediction time of 45 ± 8 s. The joint CNN-RNN model with an attention mechanism yielded excellent diagnostic accuracy in assessing ICH and its subtypes on a large-scale sample. The model was seamlessly integrated into the radiology workflow. Though slightly decreased performance, it provided decisions on the sample of consecutive real-world patients within a minute. [ABSTRACT FROM AUTHOR]

To evaluate the utility of cardiac magnetic resonance feature tracking-derived left ventricular strain in assessing cardiac dysfunction and investigate the correlation between left ventricular strain and myocardial T2* in patients with beta-thalassaemia major. Forty-two patients with beta-thalassaemia major, having a mean age of 22.49 ± 8.48 years, and age-matched healthy controls were enrolled in the study. The observer drew regions of interest on the interventricular septum, and T2* decay curves were calculated accordingly. The short-axis cine images were used to derive left ventricular circumferential and radial strains, and the long-axis four-chamber and two-chamber images were used to assess left ventricular longitudinal strain. The mean global left ventricular strains were lower in beta-thalassaemia major patients than the controls (p < 0.05). Left ventricular strains of beta-thalassaemia major patients with cardiac T2* values of > 20 ms were also significantly reduced compared with the controls (p < 0.05); there was no difference between the mean left ventricular ejection fractions of the two groups (p = 0.84). Cardiac T2* showed a weak correlation with left ventricular ejection fraction (r = 0.33, p = 0.03), while the left ventricular circumferential strain showed a good positive correlation with cardiac T2* (r = 0.6, p < 0.0001). Compared with healthy controls, patients with beta-thalassaemia major, including those with myocardial T2* values of >20 ms, showed reduced global left ventricular strains. Left ventricular circumferential strain was positively correlated with myocardial T2*. Left ventricular strain analysis using cardiac magnetic resonance feature tracking may have utility in beta-thalassaemia major assessment. Patients with beta-thalassaemia major, including those with myocardial T2* values of >20 ms, had reduced global left ventricular strains. Cardiac T2* showed a weak correlation with left ventricular ejection fraction, while the left ventricular circumferential strain showed a good positive correlation with cardiac T2*. Left ventricular strain using cardiac magnetic resonance feature tracking might be used as an adjunct in assessing cardiac functions in beta-thalassaemia major. [ABSTRACT FROM AUTHOR]

There is little evidence on the applicability of deep learning (DL) in the segmentation of acute ischemic lesions on diffusion-weighted imaging (DWI) between magnetic resonance imaging (MRI) scanners of different manufacturers. We retrospectively included DWI data of patients with acute ischemic lesions from six centers. Dataset A (n = 2986) and B (n = 3951) included data from Siemens and GE MRI scanners, respectively. The datasets were split into the training (80%), validation (10%), and internal test (10%) sets, and six neuroradiologists created ground-truth masks. Models A and B were the proposed neural networks trained on datasets A and B. The models subsequently fine-tuned across the datasets using their validation data. Another radiologist performed the segmentation on the test sets for comparisons. The median Dice scores of models A and B were 0.858 and 0.857 for the internal tests, which were non-inferior to the radiologist's performance, but demonstrated lower performance than the radiologist on the external tests. Fine-tuned models A and B achieved median Dice scores of 0.832 and 0.846, which were non-inferior to the radiologist's performance on the external tests. The present work shows that the inter-vendor operability of deep learning for the segmentation of ischemic lesions on DWI might be enhanced via transfer learning; thereby, their clinical applicability and generalizability could be improved. [ABSTRACT FROM AUTHOR]

Objectives: The cardiac cycle might impair the reproducibility of radiomics features of cardiac magnetic resonance (CMR) cine images, yet this issue has not been addressed in the previous research. We aim to evaluate whether radiomics features of CMR cine images vary during the cardiac cycle and investigate the reproducibility of radiomics features of CMR cine images. Methods: This retrospective study enrolled 59 healthy adults who underwent CMR examination. Two observers segmented the myocardium on a 4D stack of three consecutive mid-ventricular short-axis cine images covering the cardiac cycle. A total of 352 radiomics features were extracted. The coefficient of variation and intraclass correlation coefficient were used to assess the feature variability through the cycle and inter-observer reproducibility, respectively. Results: Approximately 55% of radiomics features showed large variability through the cardiac cycle. The original features showed more variability than the Laplacian of Gaussian-filtered features (73.8% vs. 48%). The features of 4D stack cine images had a higher proportion of reproducible features (92.0%, 87.7%, and 76.1%) compared with the end-diastolic (77.8%, 62.2%, and 41.7%) and the end-systolic images (81.5%, 74.1%, and 58.8%) for intraclass correlation cut-off values of 30.80, > 0.85, and > 0.90, respectively. Conclusions: Radiomics features of CMR cine images greatly vary during the cardiac cycle. The radiomics features of 4D stack of cine images are more robust compared with end-diastolic and end-systolic cine images in terms of reproducibility. The impact of the cardiac cycle on the reproducibility of the features should be considered when employing CMR cine images radiomics. Key Points: • There is limited evidence on the impact of cardiac motion on radiomics features of CMR cine images and the reproducibility of the radiomics features of CMR cine images. • Radiomics features of non-enhanced CMR cine images greatly vary during the cardiac cycle, and the number of "reproducible" features shows significant variations according to the cardiac phases. • The impact of cardiac cycle on the reproducibility of the radiomics features should be considered when employing CMR cine images radiomics. [ABSTRACT FROM AUTHOR]

Background: The maximum left atrial volume index is the most widely used metric for assessing the left atrium in hypertrophic cardiomyopathy; however, it may be normal in the early phases of the disease. Objective: To assess whether pediatric hypertrophic cardiomyopathy patients with normal maximum left atrial volume index have impaired atrial functions on cardiac magnetic resonance imaging (MRI). Materials and method: A total of 26 pediatric hypertrophic cardiomyopathy patients and 24 age-matched children, as controls, were enrolled in the study. The left atrial reservoir, conduit and booster strain were calculated from two orthogonal planes and the left atrial volumes were calculated using the biplanar method. The extent of left ventricular late gadolinium enhancement (LGE-%) was calculated using the thresholding method. The left ventricular early diastolic longitudinal strain rate was calculated to assess diastolic dysfunction. Results: The maximum left atrial volume index of the children with hypertrophic cardiomyopathy and the controls were not significantly different (P>0.05). Most of the left atrial functional indices were worse in children with hypertrophic cardiomyopathy (P<0.05), yet no difference was observed between the left atrial booster strains of the two groups (P>0.05). The left atrial conduit strain showed moderate to good negative correlations with left ventricular LGE-% and diastolic dysfunction. Conclusion: Left atrial conduit and reservoir strains are impaired in pediatric hypertrophic cardiomyopathy patients with normal maximum left atrial volumetric indices. Most left atrial strain parameters are closely linked to left ventricular LGE-% and diastolic dysfunction. Left atrial strain analysis may reveal subtle functional changes in the atrium before the increase in the maximum volume index. [ABSTRACT FROM AUTHOR]

Background Diastolic dysfunction in hypertrophic cardiomyopathy (HCM) patients is a frequent, yet poorly understood phenomenon. Purpose The purpose of this study is to assess the relationship between the myocardial fibrosis and diastolic dysfunction in patients with HCM. Materials and Methods We retrospectively investigated the impact of the myocardial fibrosis, as assessed by the extent of late gadolinium enhancement (LGE-%) on cardiac magnetic resonance imaging (CMRI), on diastolic dysfunction in 110 patients with HCM. The diastolic dysfunction was evaluated by the left atrial (LA) volume index measured on CMRI and lateral septal E/E′ ratio calculated on echocardiography. Results : There was a moderate correlation between the LGE-% and LA volume (r = 0.59, p < 0.0001). The logistic regression model of LGE-%, mitral regurgitation, and total left ventricular mass that investigated the independent predictors of LA volume identified LGE-% as the only independent parameter associated with the LA volume index (β = 0.30, p = 0.003). No correlation was observed between the LGE-% and E/E′(r = 0.24, p = 0.009). Conclusions Myocardial fibrosis in HCM patients is associated with a chronic diastolic burden as represented by increased LA volume. However, the fibrosis does not influence the E/E′ ratio, which is a well-known parameter of ventricular relaxation, restoring forces, and filling pressure. [ABSTRACT FROM AUTHOR]

Aim: To evaluate whether patients with anterior cruciate ligament (ACL) graft tear who do not undergo revision reconstruction surgery are more likely to exhibit osteoarthritic features than patients with intact ACL graft using MRI. Materials and methods: We retrospectively evaluated our hospital medical archive for identifying all consecutive patients with ACL graft failure who underwent MRI between January 2015 and January 2019. An equal number of patients with intact ACL graft was selected for the control group. An observer with 6 years of musculoskeletal radiology experience evaluated the baseline and last available follow-up MRIs of the patients for bone marrow lesions (BMLs), cartilage defects, osteophytes, anterior tibial translation, and effusion-synovitis. Results: A total of 130 patients, 118 males (90.8%), and 12 females (9.2%), with the mean age of 29.22 ± 9.3 years, were enrolled in the study. Of 130 patients, 65 had a deficient ACL graft, and 65 had an intact ACL graft. The time from the index injury to the last follow-up MRI was 45 months (IQR, 19) for the study cohort. On the follow-up MRIs, patients with ACL graft deficiency showed more prominent degenerative features compared with the patients with intact ACL graft characterized as follows: higher grades of medial meniscal tears (P = 0.06); higher grades of BMLs in the anteromedial (P = 0.014) and posteromedial (P = 0.006) femur, higher grades of cartilage defects in the medial patella (p = 0.0P); higher grades of osteophytes in the anteromedial (P = 0.018) and central medial femur (p = 0.048), central medial tibia (P = 0.048), and medial patella (P = 0.07); and more frequent anterior tibial translation (P = 0.022). Conclusion: Patients with ACL graft deficiency present with more prominent degenerative features, particularly on the medial side, suggestive of osteoarthritis compared with patients with intact ACL grafts in the medium-term follow-up. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the diagnostic accuracy of the current criterion, noncompacted-to-compacted (NC/C) wall ratio > 2.3 on cardiac magnetic resonance imaging (CMRI) for the diagnosis of left ventricular noncompaction (LVNC). Materials and Methods: We retrospectively enrolled 37 patients as an LVNC group and a total of 97 participants with ischemic, hypertrophic, and dilated cardiomyopathy and healthy controls as a control group. The NC/C ratio was measured perpendicularly on short-axis cine images for segments 1-16 and four-chamber cine images for the apex during the end-diastole. The sensitivity, specificity, and diagnostic accuracy of NC/C ratio > 2.3 for the diagnosis of LVNC were calculated. Results: LVNC patients comprised 24 males (64.8%) and 13 females (35.2%) with the mean age of29.24 ± 11.79 years. The NC/C ratio > 2.3 detected in all but one of the LVNC patients (97.3%). On the other hand, the specificity of NC/C ratio > 2.3 was 79.4% for the diagnosis of the LVNC patients. Using NC/C ratio > 2.66 and > 2.8 yielded 91.9% sensitivity and 97% specificity, and 81% sensitivity and 100% specificity, respectively. Conclusion: NC/C ratio > 2.3 might lead to overdiagnosis of LVNC. We suggest using higher NC/C cut-off value in individuals without high clinical suspicion of LVNC. [ABSTRACT FROM AUTHOR]