Evolution of CT findings in patients with mild COVID-19 pneumonia.

OBJECTIVES: To delineate the evolution of CT findings in patients with mild COVID-19 pneumonia. METHODS: CT images and medical records of 88 patients with confirmed mild COVID-19 pneumonia, a baseline CT, and at least one follow-up CT were retrospectively reviewed. CT features including lobar distribution and presence of ground glass opacities (GGO), consolidation, and linear opacities were analyzed on per-patient basis during each of five time intervals spanning the 3 weeks after disease onset. Total severity scores were calculated. RESULTS: Of patients, 85.2% had travel history to Wuhan or known contact with infected individuals. The most common symptoms were fever (84.1%) and cough (56.8%). The baseline CT was obtained on average 5 days from symptom onset. Four patients (4.5%) had negative initial CT. Significant differences were found among the time intervals in the proportion of pulmonary lesions that are (1) pure GGO, (2) mixed attenuation, (3) mixed attenuation with linear opacities, (4) consolidation with linear opacities, and (5) pure consolidation. The majority of patients had involvement of ≥ 3 lobes. Bilateral involvement was more prevalent than unilateral involvement. The proportions of patients observed to have pure GGO or GGO and consolidation decreased over time while the proportion of patients with GGO and linear opacities increased. Total severity score showed an increasing trend in the first 2 weeks. CONCLUSIONS: While bilateral GGO are predominant features, CT findings changed during different time intervals in the 3 weeks after symptom onset in patients with COVID-19. KEY POINTS: • Four of 88 (4.5%) patients with COVID-19 had negative initial CT. • Majority of COVID-19 patients had abnormal CT findings in ≥ 3 lobes. • A proportion of patients with pure ground glass opacities decreased over the 3 weeks after symptom onset.

Case report: Uncommon manifestations of Rosai-Dorfman disease in the liver mimicking HCC.

Rosai-Dorfman-Destombes disease (RDD) is a rare non-Langerhans cell histiocytosis (LCH) disorder characterized by systemic extranodal lesions. Common cases include skin lesions, whereas liver lesions are rare. This study presents a case of a 66-year-old woman with a solitary extranodal liver lesion who underwent successful surgical treatment followed by glucocorticoid therapy. The patient did not experience any symptoms before surgery. The liver lesion was incidentally discovered during a routine ultrasound examination. Enhanced CT scan revealed the lesion with the characteristic of washout, similar to primary hepatic cancer (HCC). CT scans of the head, neck, chest, and abdominal pelvis revealed no lymph node or other organ lesions. After surgery, the liver lesion was diagnosed as RDD, and subsequent whole-body examinations did not reveal any skin lesions. The definitive diagnosis was solid liver RDD in adults. Although there were no typical cases of bilateral cervical lymph node lesions, ultrasound and CT examinations promptly detected liver lesions, leading to the correct diagnosis through surgical resection. The findings from this case indicate that RDD can occur in rare extrasegmental areas, and the imaging characteristics of liver lesions are not specific, indicating the importance of avoiding delayed diagnosis.

A novel approach for automatic segmentation of prostate and its lesion regions on magnetic resonance imaging.

Objective: To develop an accurate and automatic segmentation model based on convolution neural network to segment the prostate and its lesion regions. Methods: Of all 180 subjects, 122 healthy individuals and 58 patients with prostate cancer were included. For each subject, all slices of the prostate were comprised in the DWIs. A novel DCNN is proposed to automatically segment the prostate and its lesion regions. This model is inspired by the U-Net model with the encoding-decoding path as the backbone, importing dense block, attention mechanism techniques, and group norm-Atrous Spatial Pyramidal Pooling. Data augmentation was used to avoid overfitting in training. In the experimental phase, the data set was randomly divided into a training (70%), testing set (30%). four-fold cross-validation methods were used to obtain results for each metric. Results: The proposed model achieved in terms of Iou, Dice score, accuracy, sensitivity, 95% Hausdorff Distance, 86.82%,93.90%, 94.11%, 93.8%,7.84 for the prostate, 79.2%, 89.51%, 88.43%,89.31%,8.39 for lesion region in segmentation. Compared to the state-of-the-art models, FCN, U-Net, U-Net++, and ResU-Net, the segmentation model achieved more promising results. Conclusion: The proposed model yielded excellent performance in accurate and automatic segmentation of the prostate and lesion regions, revealing that the novel deep convolutional neural network could be used in clinical disease treatment and diagnosis.

Coronal T2-weighted imaging improves the measurement accuracy of the subarachnoid space in infants: A descriptive study.

Background: The subarachnoid space width (SASw) is part of crucial neuroimaging criteria for the diagnosis of subarachnoid space enlargement in infants. In addition to indicating the presence of these diseases, SASw can be used to assess their severity. Therefore, it is important to be able to measure the SASw accurately. Aim: This study aimed to compare the accuracy of measurements made from axial and coronal T2-weighted imaging (T2WI) and to establish a consentaneous measurement scheme of SASw in infants. Methods: A total of 63 infants (31 males and 32 females) aged 4 days to 24 months were enrolled in this study. The supratentorial subarachnoid space volume (SASv) and corrected SASv (cSASv) were used as the gold standard reference. The SASw (including interhemispheric width and bilateral frontal craniocortical width) was measured on axial and coronal T2WI. The intra- and inter-observer reproducibility and agreement of the SASw were assessed by the intraclass correlation coefficient (ICC) and Bland-Altman analysis. A paired t-test was used to compare SASw measured on axial and coronal images. The accuracy of SASw measurements made from axial and coronal T2WI was evaluated by the relationships between the SASw and supratentorial SASv and between the SASw and supratentorial cSASv, and the relationships were examined by multivariate linear regression. Results: The intra- and inter-observer ICC values of the three SASw measurements were greater on coronal T2WI than on axial T2WI. Bland-Altman analysis confirmed that the SASw values measured on coronal T2WI had better intra- and inter-observer agreement than axial T2WI. According to the multivariate linear regression results, model 4 (the SASw measured in coronal T2WI) was the best predictor of supratentorial cSASv (R2 = 0.755). Conclusions: The SASw measured on coronal T2WI was more repeatable and accurate than axial T2WI and was more representative of the actual cerebrospinal fluid accumulation in the supratentorial subarachnoid space. Relevance for Patients: The SASw has been found to be a simple and essential substitution for supratentorial SASv, which can be measured on both axial T2WI passing through the bodies of the bilateral ventricles and coronal T2WI at the level of the foramen of Monro. The SASw measured on coronal T2WI was more beneficial to the diagnosis and severity assessment of subarachnoid space enlargement in infants.

Changes in the Shape and Volume of Subcortical Structures in Patients With End-Stage Renal Disease.

Introduction: End-stage renal disease (ESRD) typically causes changes in brain structure, and patients with ESRD often experience cognitive and sleep disorders. We aimed to assess the changes in the subcortical structure of patients with ESRD and how they are associated with cognitive and sleep disorders. Methods: We involved 36 adult patients for maintenance hemodialysis and 35 age- and gender-matched control individuals. All participants underwent neuropsychological examination and 3T magnetic resonance imaging (MRI) to acquire T1 anatomical images. The laboratory blood tests were performed in all patients with ESRD close to the time of the MR examination. We used volumetric and vertex-wise shape analysis approaches to investigate the volumes of 14 subcortical structural (e.g., bilateral accumbens, amygdala, hippocampus, caudate, globus pallidus, putamen, and thalamus) abnormalities in the two groups. Analyses of partial correlations and shape correlations were performed in order to identify the associations between subcortical structure, cognition, and sleep quality in patients with ESRD. Results: The volumetric analysis showed that compared with the healthy control group, patients with ESRD had less bilateral thalamus (left: p < 0.001; right: p < 0.001), bilateral accumbens (left: p < 0.001; right: p = 0.001), and right amygdala (p = 0.002) volumes. In the vertex-wise shape analysis, patients with ESRD had abnormal regional surface atrophy in the bilateral thalamus, right accumbens, left putamen, and bilateral caudate. Moreover, the Montreal Cognitive Assessment (MoCA) score was associated with volume reduction in the bilateral thalamus (left: Spearman ρ = 0.427, p = 0.009; right: ρ = 0.319, p = 0.018), and the Pittsburgh Sleep Quality Index (PSQI) score was associated with volume reduction in the bilateral accumbens (left: ρ = -0.546, p = 0.001; right: ρ = -0.544, p = 0.001). In vertex-wise shape correlation analysis, there was a positive significant correlation between regional shape deformations on the bilateral thalamus and MoCA score in patients with ESRD. Conclusion: Our study suggested that patients with ESRD have subcortical structural atrophy, which is related to impaired cognitive performance and sleep disturbances. These findings may help to further understand the underlying neural mechanisms of brain changes in patients with ESRD.

The relationship between quantitative epicardial adipose tissue based on CT and coronary artery disease: A protocol for systematic review and meta-analysis.

BACKGROUND: Epicardial adipose tissue (EAT) is a kind of visceral adipose tissue with close proximity to coronary artery and myocardium, which can secrete cell factor, and influence the physiological function and pathophysiological process of myocardium and coronary artery. Clinical imaging diagnosis showed that the volume and thickness of EAT exists a certain relevance with coronary artery disease, but it lacked evidence of evidence-based medicine. The research on the implementation of this program will systematically evaluate the relationship of computed tomography (CT) quantitative EAT and coronary artery disease. METHOD: The English databases (Embase, PubMed, the Cochrane Library, Web of Science) and Chinese database (CNKI, Wanfang, China biomedical database, VIP) of computer retrieval has collected the case control clinical study of relationship between EAT and coronary artery disease from the establishment of the database to October 2020, which was conducted extraction and quality evaluation by 2 researchers independently for data included in the study, and was conducted Meta-analysis for the included literature by adopting RevMan5.3 software. RESULT: The research evaluated the correlation between EAT and coronary artery disease through the EAT thickness, EAT volume, and other indexes. CONCLUSION: The research has provided reliable evidence-based evidence for the correlation between CT EAT quantification and coronary artery disease. ETHICS AND DISSEMINATION: We will not publish private information from individuals. This kind of systematic review does not involve harming the rights of participants. No ethical approval was required. The results can be published in peer-reviewed journals or at relevant conferences. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/DVQNE.

Investigation of quantitative susceptibility mapping in diagnosis of tuberous sclerosis complex and assessment of associated brain injuries at 1.5 Tesla.

BACKGROUND AND AIM: Tuberous sclerosis complex (TSC) is a rare disease with serious clinical consequences such as mental deficiency and epilepsy. The pathological changes of TSC include demyelination and subependymal calcified nodules. Quantitative susceptibility mapping (QSM) is a newly developed imaging technique which is capable of quantitatively measuring the susceptibility induced by iron deposition, calcification, and demyelination. The aim of this study was to investigate the use of QSM in detecting the subependymal nodules and assessing brain tissue injuries induced by cortical/subcortical tubers in TSC patients. MATERIALS AND METHODS: Twelve clinically confirmed TSC patients and fifteen gender- and age-matched healthy subjects underwent measurement with conventional magnetic resonance imaging (MRI) sequences, diffusion tensor imaging (DTI), and QSM. The TSC patients further underwent a computed tomography (CT) scan. Considering CT as the ground truth, the detection rates of subependymal nodules using conventional MRI and QSM were compared by the paired Chi-square test, and the sensitivity and specificity were computed. The Bland-Altman test and independent t-test were performed to compare the susceptibility of cortical/subcortical regions from QSM and fractional anisotropy (FA) values from DTI between the patient and control groups, Pearson correlation was performed to examine the correlation between the susceptibility and FA values. RESULTS: QSM was better in detecting subependymal calcified nodules compared to conventional MR sequences (X 2=40.18, P<0.001), QSM achieved a significantly higher sensitivity of 98.3% and a lower specificity of 50%, which was compared with conventional MR sequences (46.7% and 75%, respectively). The susceptibility value of cortical/subcortical tubers in TSC patients was significantly higher than those in the control group (t=9.855, P<0.001), while FA value was lower (t=-8.687, P<0.001). Pearson correlation test revealed a negative correlation between susceptibility and FA values in all participants (r=-0.65, P<0.001). CONCLUSIONS: QSM had a similar ability in TSC compared to CT and DTI. QSM may provide valuable complementary information to conventional MRI imaging and may simplicity imaging of patients with TSC. RELEVANCE FOR PATIENTS: This study shows the feasibility of QSM to detect subependymal calcified nodules. It may provide quantitative information of white matter damage of tuberous sclerosis patients.

A comparison study of inhomogeneous magnetization transfer (ihMT) and magnetization transfer (MT) in multiple sclerosis based on whole brain acquisition at 3.0 T.

INTRODUCTION: Multiple sclerosis (MS) is a central nervous system disorder that may eventually affect its function. The clinical standard for MS severity is based on a clinical scale, which lacks lesion specific information. Magnetic resonance imaging of MS faces the challenge of myelin specificity, and in this work a new method inhomogeneous magnetization transfer (ihMT) is investigated as new biomarker of demyelination in MS. METHODS: Local ethics committee approved this study and written informed consents were obtained. Between Oct 2017 to May 2018, eighteen patients with relapsing-remitting MS (RRMS) (6 males, 12 females, mean age 31.2) and sixteen healthy volunteers (6 males, 10 females, mean age 30.4 years) were enrolled in this prospective study. All subjects underwent MRI exams including MT and ihMT imaging as well as the Expanded Disability Status Scale (EDSS) assessments. Independent sample t-test were used to compare the difference of ihMT parameters between healthy white matter (HWM) and normal appearing white matter (NAWM) and between HWM and MS lesions, respectively. Spearman correlation were used to analyze the correlation between ihMT parameters of MS lesions and EDSS score. RESULTS: The ihMTR and qihMT demonstrate significant differences between WHM and NAWM groups, while no significant differences are observed for MTR and qMT. All parameters show significant differences between HWM and MS groups (p < 0.05). There was moderate negative correlation between MTR, qMT and EDSS score (-0.440 and -0.572), while there was a strong negative correlation between ihMTR and qihMT and EDSS score (-0.704 and -0.739). CONCLUSION: Based on whole brain analysis at 3.0 T, ihMT showed better correlation with EDSS compared to magnetization transfer imaging, and may be a potentially valuable biomarker for demyelination in MS.

A Pattern Categorization of CT Findings to Predict Outcome of COVID-19 Pneumonia.

Background: As global healthcare system is overwhelmed by novel coronavirus disease (COVID-19), early identification of risks of adverse outcomes becomes the key to optimize management and improve survival. This study aimed to provide a CT-based pattern categorization to predict outcome of COVID-19 pneumonia. Methods: One hundred and sixty-five patients with COVID-19 (91 men, 4-89 years) underwent chest CT were retrospectively enrolled. CT findings were categorized as Pattern 0 (negative), Pattern 1 (bronchopneumonia pattern), Pattern 2 (organizing pneumonia pattern), Pattern 3 (progressive organizing pneumonia pattern), and Pattern 4 (diffuse alveolar damage pattern). Clinical findings were compared across different categories. Time-dependent progression of CT patterns and correlations with clinical outcomes, i.e." discharge or adverse outcome (admission to ICU, requiring mechanical ventilation, or death), with pulmonary sequelae (complete absorption or residuals) on CT after discharge were analyzed. Results: Of 94 patients with outcome, 81 (86.2%) were discharged, 3 (3.2%) were admitted to ICU, 4 (4.3%) required mechanical ventilation, 6 (6.4%) died. 31 (38.3%) had complete absorption at median day 37 after symptom onset. Significant differences between pattern-categories were found in age, disease severity, comorbidity and laboratory results (all P < 0.05). Remarkable evolution was observed in Pattern 0-2 and Pattern 3-4 within 3 and 2 weeks after symptom-onset, respectively; most of patterns remained thereafter. After controlling for age, CT pattern significantly correlated with adverse outcomes [Pattern 4 vs. Pattern 0-3 [reference]; hazard-ratio [95% CI], 18.90 [1.91-186.60], P = 0.012]. CT pattern [Pattern 3-4 vs. Pattern 0-2 [reference]; 0.26 [0.08-0.88], P = 0.030] and C-reactive protein [>10 vs. ≤ 10 mg/L [reference]; 0.31 [0.13-0.72], P = 0.006] were risk factors associated with pulmonary residuals. Conclusion: CT pattern categorization allied with clinical characteristics within 2 weeks after symptom onset would facilitate early prognostic stratification in COVID-19 pneumonia.

Recent Advances in Rational Diagnosis and Treatment of Normal Pressure Hydrocephalus: A Critical Appraisal on Novel Diagnostic, Therapy Monitoring and Treatment Modalities.

BACKGROUND: Normal pressure hydrocephalus (NPH) is a critical brain disorder in which excess Cerebrospinal Fluid (CSF) is accumulated in the brain's ventricles causing damage or disruption of the brain tissues. Amongst various signs and symptoms, difficulty in walking, slurred speech, impaired decision making and critical thinking, and loss of bladder and bowl control are considered the hallmark features of NPH. OBJECTIVE: The current review was aimed to present a comprehensive overview and critical appraisal of majorly employed neuroimaging techniques for rational diagnosis and effective monitoring of the effectiveness of the employed therapeutic intervention for NPH. Moreover, a critical overview of recent developments and utilization of pharmacological agents for the treatment of hydrocephalus has also been appraised. RESULTS: Considering the complications associated with the shunt-based surgical operations, consistent monitoring of shunting via neuroimaging techniques hold greater clinical significance. Despite having extensive applicability of MRI and CT scan, these conventional neuroimaging techniques are associated with misdiagnosis or several health risks to patients. Recent advances in MRI (i.e., Sagittal-MRI, coronal-MRI, Time-SLIP (time-spatial-labeling-inversion-pulse), PC-MRI and diffusion-tensor-imaging (DTI)) have shown promising applicability in the diagnosis of NPH. Having associated with several adverse effects with surgical interventions, non-invasive approaches (pharmacological agents) have earned greater interest of scientists, medical professional, and healthcare providers. Amongst pharmacological agents, diuretics, isosorbide, osmotic agents, carbonic anhydrase inhibitors, glucocorticoids, NSAIDs, digoxin, and gold-198 have been employed for the management of NPH and prevention of secondary sensory/intellectual complications. CONCLUSION: Employment of rational diagnostic tool and therapeutic modalities avoids misleading diagnosis and sophisticated management of hydrocephalus by efficient reduction of Cerebrospinal Fluid (CSF) production, reduction of fibrotic and inflammatory cascades secondary to meningitis and hemorrhage, and protection of brain from further deterioration.

Reproducibility of inhomogeneous magnetization transfer (ihMT): A test-retest, multi-site study.

BACKGROUND: Inhomogeneous magnetization transfer (ihMT) has been reported to feature superior sensitivity and specificity for myelin imaging. However, the reproducibility on ihMT has yet been rarely investigated up to date. The purpose of the present study is to assess the multi-center reproducibility and test-retest variability of ihMT in central nervous system. METHODS: 5 volunteers were recruited and scanned twice on three 3.0 T magnetic resonance imaging (MRI) scanners using ihMT with identical scan parameters. The maps of quantitative ihMT (qihMT) and ihMT ratio (ihMTR) for each scan were calculated. Voxel based analysis then was performed to generate qihMT and ihMTR values for major white matter fibers. The intra- and inter-scanner reliability and reproducibility was assessed with intraclass correlation coefficients (ICCs). Bland-Altman method was used to show the level of agreement between two measurement types. Paired t-test and one-way ANOVA test were also used to compare the difference between inter- and intra-scanner, respectively. RESULTS: In the 10 major white matter tracts areas, the ICCs indicated high intra- and inter-scanner measurement reliability and reproducibility. The Bland-Altman plots together with 95% confidence interval (CI) across all ROIs in the five volunteers also demonstrated good repeatability. No significant inter- and intra-scanner differences were found in Paired t-test and one-way ANOVA tests. CONCLUSION: Good inter- and intra-scanner reliability and reproducibility of ihMT measurements were observed in this study. These findings support the use of ihMT measurements as biomarkers in multicenter and/or longitudinal studies.

Assessment of iron deposition and white matter maturation in infant brains by using enhanced T2 star weighted angiography (ESWAN): R2* versus phase values.

BACKGROUND AND PURPOSE: Iron deposition and white matter (WM) maturation are very important for brain development in infants. It has been reported that the R2* and phase values originating from the gradient-echo sequence could both reflect the iron and myelination. The aim of this study was to investigate age-related changes of R2* and phase value, and compare their performances for monitoring iron deposition and WM maturation in infant brains. METHODS: 56 infants were examined by enhanced T2 star weighted angiography (ESWAN) and diffusion tensor imaging in the 1.5T MRI system. The R2* and phase values were measured from the deep gray nuclei and WM. Fractional anisotropy (FA) values were measured only in the WM regions. Correlation analyses were performed to explore the relation among the two parameters (R2* and phase values) and postmenstrual age (PMA), previously published iron concentrations as well as FA values. RESULTS: We found significantly positive correlations between the R2* values and PMA in both of the gray nuclei and WM. Moreover, R2* values had a positive correlation with the iron reference concentrations in the deep gray nuclei and the FA in the WM. However, phase values only had the positive correlation with PMA and FA in the internal capsule, and no significant correlation with PMA and iron content in the deep gray nuclei. CONCLUSIONS: Compared with the phase values, R2* may be a preferable method to estimate the iron deposition and WM maturation in infant brains.