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Background: Congenital mesoblastic nephroma is the most common solid renal tumor in neonates. Therefore, patients <3 months of age are advised to undergo upfront nephrectomy, whereas invasive procedures at diagnosis in patients ≥3 months of age are discouraged by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Nevertheless, discriminating congenital mesoblastic nephroma, especially from the more common Wilms tumor, solely based on imaging remains difficult. Recently, magnetic resonance imaging (MRI) has become the preferred modality. Studies focusing on MRI characteristics of congenital mesoblastic nephroma are limited., Objective: This study aims to identify diagnostic MRI characteristics of congenital mesoblastic nephroma in the largest series of patients to date., Materials and Methods: In this retrospective multicenter study, five SIOP-RTSG national review radiologists identified 52 diagnostic MRIs of histologically proven congenital mesoblastic nephromas. MRI was performed following SIOP-RTSG protocols, while radiologists assessed their national cases using a validated case report form., Results: Patients (24/52 classic, 11/52 cellular, and 15/52 mixed type congenital mesoblastic nephroma, 2/52 unknown) had a median age of 1 month (range 1 day-3 months). Classic type congenital mesoblastic nephroma appeared homogeneous with a lack of hemorrhage, necrosis and/or cysts, showing a concentric ring sign in 14 (58.3%) patients. Cellular and mixed type congenital mesoblastic nephroma appeared more heterogeneous and were larger (311.6 and 174.2 cm 3 , respectively, versus 41.0 cm 3 for the classic type (P<0.001)). All cases were predominantly T2-weighted isointense and T1-weighted hypointense, and mean overall apparent diffusion coefficient values ranged from 1.05-1.10×10 -3 mm 2 /s., Conclusion: This retrospective international collaborative study showed classic type congenital mesoblastic nephroma predominantly presented as a homogeneous T2-weighted isointense mass with a typical concentric ring sign, whereas the cellular type appeared more heterogeneous. Future studies may use identified MRI characteristic of congenital mesoblastic nephroma for validation and for exploring the discriminative non-invasive value of MRI, especially from Wilms tumor., (© 2024. The Author(s).)

Purpose: Tumor segmentation constitutes a crucial step in simulating cancer growth and response to therapy. Incorporation of imaging data individualizes the simulation and assists clinical correlation with the predicted outcome. We adapted snakes to improve tumor segmentation including difficult cases with inherently inhomogeneous structure and poorly defined margins., Methods: Snakes are flexible curves, based on the parameter-controlled deformation of an initial user-defined contour toward the boundary of the desired object, through the minimization of a suitable energy function. Although parameter-adjustment can yield fairly good results in homogeneous regions, traditional snakes often fail to provide an accurate segmentation result when both rigid and very elastic behavior is needed simultaneously to delineate the true outline of the tumor. We developed and tested a spatially adaptive active contour technique by introducing local snake bending, to improve traditional snakes performance for segmenting tumors. The key point of our method is the use of adaptable snake parameters, instead of constant ones, to adjust the bending of the curve according to the local edge characteristics. Our algorithm discriminates image regions according to underlying image features, such as gradient magnitude and corner strength. More specifically, it assigns each region a different "localized" set of parameters, one corresponding to a very flexible snake, and the other corresponding to a very rigid one, according to the local image characteristics., Results: Qualitative results on more than 150 real MR images, as well as quantitative validation based on agreement with an expert clinician's annotations of the true tumor boundaries, demonstrate our approach is highly efficient compared to traditional active contours and region growing. Due to the use of adaptable parameters in the snake evolution process, our approach outperforms the other two methods, and consistently follows an expert's annotations. Statistical tests indicated significant difference between the results produced by our approach and two other algorithms traditional snakes and region growing, while multiple comparison showed that our method consistently outperformed those algorithms, with an average overlap of 89%, over the entire data set, while traditional snakes were at 82.5% and region growing at 59.2%. Furthermore, we performed several tests that demonstrate our method's stability to different initial contours, as well as, to lower resolution images., Conclusion: Our adaptive snake algorithm can spatially adapt to diverse image characteristics, producing outlines that mimic the true tumor boundaries. Results in MR datasets are very close to an expert clinician's intuition about the tumor boundaries.

Magnetic resonance imaging (MRI) presents the main diagnostic tool for differentiation and staging of renal tumors in childhood. Nephroblastoma is the most common malignant tumor in children. Radiological findings play an important role in therapy study trials of SIOP (International Society of Pediatric Oncology), especially for indicating preoperative chemotherapy. In the past few years MRI has gained great importance in imaging of nephroblastoma and has replaced computed tomography (CT). The aim of this review is to present the diagnostic possibilities of MRI in relation to the requirements of therapy studies. For nephroblastoma, MRI provides important information about tumor extent and distant metastasis. A special focus of MRI in distant staging is venous extent of the tumor into the inferior vena cava. In addition, MRI has an important role in monitoring chemotherapy and in preoperative planning by volume rendering and three-dimensional postprocessing.

Nephroblastomatosis is a paediatric renal disease that may undergo malignant transformation. When neoadjuvant chemotherapy is indicated for nephroblastomatosis or bilateral Wilms' tumours, exact volumetric analysis using high-speed data processing and visualization may aid in determining tumour response. Using 3D-volume-rendering software, the 0.5-T MRI data of a 2-year-old girl with bilateral nephroblastomatosis was analysed. Exact volume determination of foci of nephroblastomatosis was performed by automatic and manual segmentation, and the relation to normal renal parenchyma was determined over a 12-month period. At the first visit, 80% (460/547 ml) of the extremely enlarged right kidney was due to nephroblastomatosis. Total tumour volume within the right kidney decreased to 74 ml under chemotherapy. Volume analysis of the two emerging right-sided masses after treatment correctly suggested Wilms' tumour. Three-dimensional rendering of the growing masses aided the surgeon in nephron-sparing surgery during tumour resection.

Simple Summary: Acute leukemias in children have an excellent outcome. Therefore, reasons for long-term sequelae need to be discovered to avoid them. Our retrospective analysis in addition to a literature review focuses on neurotoxicity by investigating cerebral morphologic changes diagnosed in cranial MRIs in children with acute leukemias. Such changes occur in more than 50% of children. They were detected especially in patients below 6 years of age, in ALL and in patients receiving more than 12 intrathecal MTX applications. The ventricular width, as one of the cerebral abnormalities, has the potential to normalize again. It is important to prospectively investigate and correlate these changes with the neurocognitive outcome in children with acute leukemias to evaluate the impact of intrathecal MTX in this context. Due to high survival rates, long-term sequelae, especially neurotoxicity, need to be considered in childhood acute leukemias. In this retrospective analysis of morphologic changes of the brain in children treated for acute leukemias, we included 94 patients (77 ALL, 17 AML; 51 male, 43 female; median age: 5 years) from a single center. We analyzed 170 cranial MRI scans (T2, FLAIR axial) for morphologic alterations of the brain and variations of the ventricular width (GDAH). In addition, the corresponding literature was reviewed. More than 50% of all patients showed cerebral pathomorphologies (CP). They were seen more often in children with ALL (55.8%), ≤ 6 years of age (60.8%), in relapse (58.8%) or after CNS irradiation (75.0%) and included white matter changes, brain atrophy, sinus vein thrombosis and ischemic events. GDAH significantly enlarged mainly in children up to 6 years, with relapse, high-risk leukemias or ALL patients. However, GDAH can normalize again. The number of intrathecal Methotrexate applications (≤12 vs. >12) showed no correlation to morphologic alterations besides a significant increase in GDAH (−0.3 vs. 0.9 mm) between the first and last follow-up MRI in ALL patients receiving >12 ith. MTX applications. The role of ith. MTX on CP needs to be further investigated and correlated to the neurocognitive outcome of children with acute leukemias. [ABSTRACT FROM AUTHOR]

The objective of this study is to assess standardized histograms of signal intensities of T2-weighted magnetic resonance image (MRI) modality before and after preoperative chemotherapy for nephroblastoma (Wilms' tumor). All analyzed patients are enrolled in the International Society of Paediatric Oncology (SIOP) 2001/GPOH trial.1 The question to be answered is whether the comparison of the histograms can add new knowledge by comparing them with the histology of the tumor after preoperative chemotherapy. Twenty-three unilateral nephroblastoma cases were analyzed. All patients were examined by MRI before and after preoperative chemotherapy treatment. T2 modalities of the MRIs were selected, and histogram changes were compared to histopathological data available after surgery. Of the 23 tumors, 22 decreased in volume following chemotherapy (median -57.99%; range 15.65 to -90.82%). The preliminary results suggest that standardized histograms of signal intensities of T2 MRI in nephroblastoma is not predicting histopathological diagnostic information and has no implications for the clinical assessment for further chemotherapy. [ABSTRACT FROM AUTHOR]

Aim: Intracranial germinoma is a rare malignant tumour in childhood with an excellent prognosis under adequate therapy. Finding the right diagnosis at an early stage is difficult because of the slow-growing tumour and the resulting lack of clinical symptoms. Methods: Our patients with histologically secured germinoma were retrospectively assessed concerning growth retardation, pituitary hormone status, magnetic resonance imaging scan results and clinical symptoms to find out whether there is a leading parameter. Results: In all our patients, the leading symptom was growth retardation of at least 2 y before being diagnosed. Conclusion: Growth retardation seems to be a very early sign of germinoma in the suprasellar region. Therefore, early neuroradiological imaging combined with pituitary hormone status should be considered in every paediatric patient with a history of secondary growth retardation. [ABSTRACT FROM AUTHOR]

The incidence of a drug-induced pancreatitis is rare and so far more than 85 different drugs have been reported to have induced pancreatitis. Some case reports consider a relationship between propofol and acute pancreatitis. However, in these cases a number of different drugs were coadministered, thus preventing a clear causal link being established. We report a case of a drug-induced acute pancreatitis that was most likely triggered by a single dosage of propofol. It occurred in a young girl who underwent elective magnetic resonance imaging. She developed pancreatitis within hours after exposure to propofol. Other possible triggers, e.g. gallstones or infection were ruled out. Physicians should consider pancreatitis as a potentially life-threatening adverse event associated with propofol sedation, which is nowadays extensively used. [ABSTRACT FROM AUTHOR]

The article presents a medical case regarding a 2.5-week-old boy with intermittent episodes of gross hematuria and cystic renal mass. The urine analyses of the infant revealed a mild microhematuria and the urine culture was negative. A solid lesion of the upper pole and a mild dilatation of the upper pole collecting system of the left kidney was seen through the magnetic resonance imaging.

Abstract: A 15-year-old adolescent boy with autosomal recessive agammaglobulinemia underwent endoscopy because of unexplained growth failure and malnutrition. Esophagogastroduodenoscopy revealed antropyloric stenosis, and a biopsy showed an invasive gastric adenocarcinoma. Chronic atrophic corpus gastritis type A and Helicobacter pylori were also identified. Abdominal magnetic resonance imaging confirmed the stenosis resulting from a semicircular intramural tumor without obvious local or distant metastatic spread. Gastrectomy with an extended lymphadenectomy was performed. Esophagoduodenal continuity was restored by an interposed jejunal parallel pouch developed from the first jejunal loop. Oral feeding was supplemented by parenteral nutrition via a Broviac catheter, and the patient is well 4 months later. Several cases of gastric cancer have been reported in children with hereditary agammaglobulinemia. Thus, endoscopy is mandatory in such patients with gastrointestinal symptoms to identify and treat tumors before metastasis occurs. Total gastrectomy, extended lymphadenectomy, and reconstruction using a jejunal reservoir with maintenance of duodenal continuity should be considered. [Copyright &y& Elsevier]