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Abstract Background Renal tumors account for approximately 6–7% of the total incidence of pediatric cancers. Wilms tumor (WT) is the most common renal malignancy observed in the pediatric population under 5 years old. Computed tomography (CT) is used for staging of the renal tumors. Magnetic resonance imaging (MRI) offers enhanced soft tissue resolution and provides more comprehensive insights into tumor extension through the capsule, including tumor infiltration into the renal vein or IVC. MRI is a noninvasive imaging modality that does not involve any radiation hazards, making it safe for children. In addition, MRI can be performed without the administration of contrast agents in patients with impaired renal function. Therefore, MRI plays a vital role in screening, staging, preoperative evaluation, and follow-up. Diffusion-weighted imaging (DWI) is a functional tool that aids in locating the most receptive tumoral region to guide confirmatory biopsies. In this study, we aim to evaluate the potential value of non-contrast MRI in staging pediatric renal tumors compared to contrast-enhanced CT. Results This study included 50 patients presented with renal mass, with ages ranging from 1 to 8 years and a mean age of 4.27 ± 1.27 (mean ± SD). The final diagnosis was Wilm’s tumor at 86%, clear cell sarcoma at 4%, rhabdoid tumor at 4%, rhabdomyosarcoma at 2%, and nephroblastomatosis with no malignant transformation at 4%. CT accurately diagnosed stages 4 and 5 in agreement with pathological findings while upstaging the other cases, with a CT sensitivity of 90.91%, specificity of 82.35%, PPV of 92%, and NPV of 84%. MRI is superior to CT in stages 1 and 3, accurately diagnosing stages 2, 4, and 5, with a sensitivity of 93.30%, specificity of 95.65%, PPV of 95%, and NPV of 97%. Conclusions Non-contrast MRI could be considered the optimal radiation-free imaging modality in staging pediatric renal tumors mainly Wilm’s tumor as it offers high sensitivity and specificity of capsular and vascular infiltration, compared to contrast-enhanced CT especially in cases with impaired renal functions.

Abstract Background Cardiomyopathy is a myocardial disease, which usually demonstrates improper ventricular morphology, function, or both. It is classified into two classes based on the organ involved. Primary cardiomyopathy is confined mainly to the myocardium and can be genetic, non-genetic, or acquired. Secondary cardiomyopathy is caused by generalized systemic disorder. Myocardial fibrosis produces abnormal myocardial stiffness and increases arrhythmias risk. Native T1-mapping is an innovative technique that provides quantitative assessment of edema, diffuse myocardial fibrosis, and inflammation in a number of disease states. Furthermore native T1 mapping provides a future method for quantifying myocardial fibrosis in advanced chronic kidney disease and dialysis patients without the use of gadolinium-based contrast agents. So our aim is to assess the potential value of segmental quantification of myocardial fibrosis using native T1 mapping in different types of cardiomyopathy in comparison to late gadolinium enhancement (LGE) imaging. Results The native T1 values of a total 1152 segments (16 segments in 72 patients of cardiomyopathy), 192 segments in 12 patients with hypertrophic cardiomyopathy (HCM), 800 segments in 50 patients with dilated cardiomyopathy (DCM), 80 segments in 5 patients with infiltrative cardiomyopathy, and 80 segments in 5 patients with non-compaction were assessed. These were compared with 160 segments of 10 healthy volunteers. Native T1 values were significantly higher in most of myocardial segments with LGE than in those without including the control group; non-contrast T1 values in mid LV septal segments were found the most significant (1130.85 ± 79.79 ms vs 1047.74 ± 42.74 ms; P = 0.001). Also the current study showed T1 values were significantly higher than normal even in segments unaffected by LGE (P

Abstract Background CT chest severity score (CTSS) is a semi-quantitative measure done to correlate the severity of the pulmonary involvement on the CT with the severity of the disease. The objectives of this study are to describe chest CT criteria and CTSS of the COVID-19 infection in pediatric oncology patients, to find a cut-off value of CTSS that can differentiate mild COVID-19 cases that can be managed at home and moderate to severe cases that need hospital care. A retrospective cohort study was conducted on 64 pediatric oncology patients with confirmed COVID-19 infection between 1 April and 30 November 2020. They were classified clinically into mild, moderate, and severe groups. CT findings were evaluated for lung involvement and CTSS was calculated and range from 0 (clear lung) to 20 (all lung lobes were affected). Results Overall, 89% of patients had hematological malignancies and 92% were under active oncology treatment. The main CT findings were ground-glass opacity (70%) and consolidation patches (62.5%). In total, 85% of patients had bilateral lung involvement, ROC curve showed that the area under the curve of CTSS for diagnosing severe type was 0.842 (95% CI 0.737–0.948). The CTSS cut-off of 6.5 had 90.9% sensitivity and 69% specificity, with 41.7% positive predictive value (PPV) and 96.9% negative predictive value (NPV). According to the Kaplan–Meier analysis, mortality risk was higher in patients with CT score > 7 than in those with CTSS < 7. Conclusion Pediatric oncology patients, especially those with hematological malignancies, are more vulnerable to COVID-19 infection. Chest CT severity score > 6.5 (about 35% lung involvement) can be used as a predictor of the need for hospitalization.

Abstract Background There are some limitations using the different sequences of clinical cardiac magnetic resonance (cardiac MR) in detection of edema in patients presenting with acute myocardial injury. The purpose of this study is to evaluate the myocardial segmental agreement between the different edema sequences: T2 mapping and turbo inversion recovery magnitude (TIRM) in detection of acute myocardial edema. Results Thirty-seven patients presented with acute infarction were sent to cardiac MR to assess myocardial edema. All cardiac MR studies were scanned using cine, TIRM, and late gadolinium enhancement (LGE) in short axis views (SAX). Position of the T2 mapping slices were copied from the TIRM. The left ventricle (LV) was divided into apical, mid, and basal segments per visualization of the papillary muscles. Edema mass was assessed separately in each segment as well as the total edema mass in both the TIRM and T2 mapping. Twenty-four patients of whom 12.5% had multi-territorial coronary lesions and edema were assessed. Myocardial edema was not assessed in thirteen patients (35%) due to significant intra myocardial hemorrhage (T2 mapping