High-resolution anatomical imaging of the fetal brain with a reduced field of view using outer volume suppression.

PURPOSE: To achieve high-resolution fetal brain anatomical imaging without introducing image artifacts by reducing the FOV, and to demonstrate improved image quality compared to conventional full-FOV fetal brain imaging. METHODS: Reduced FOV was achieved by applying outer volume suppression (OVS) pulses immediately prior to standard single-shot fast spin echo (SSFSE) imaging. In the OVS preparation, a saturation RF pulse followed by a gradient spoiler was repeated three times with optimized flip-angle weightings and a variable spoiler scheme to enhance signal suppression. Simulations and phantom and in-vivo experiments were performed to evaluate OVS performance. In-vivo high-resolution SSFSE images acquired using the proposed approach were compared with conventional and high-resolution SSFSE images with a full FOV, using image quality scores assessed by neuroradiologists and calculated image metrics. RESULTS: Excellent signal suppression in the saturation bands was confirmed in phantom and in-vivo experiments. High-resolution SSFSE images with a reduced FOV acquired using OVS demonstrated the improved depiction of brain structures without significant motion and blurring artifacts. The proposed method showed the highest image quality scores in the criteria of sharpness, contrast, and artifact and was selected as the best method based on overall image quality. The calculated image sharpness and tissue contrast ratio were also the highest with the proposed method. CONCLUSION: High-resolution fetal brain anatomical images acquired using a reduced FOV with OVS demonstrated improved image quality both qualitatively and quantitatively, suggesting the potential for enhanced diagnostic accuracy in detecting fetal brain abnormalities in utero.

Fanconi-Bickel syndrome complicated by nephrocalcinosis and GFR decline.

Fanconi-Bickel syndrome (FBS) is a rare genetic disorder of carbohydrate metabolism due to pathogenic variants in SLC2A2, a gene encoding glucose transporter 2 (GLUT2), which leads to accumulation of glycogen in the kidney and liver. While consequential complex proximal tubular dysfunction is well acknowledged in the literature, long-term trajectories of kidney function in patients with FBS have not been well characterized, and kidney biopsy is performed infrequently. Here, we report on a patient with FBS followed from infancy through young adulthood who presented early on with hypercalciuria, phosphaturia, and hypophosphatemia, complicated by chronic kidney disease development during childhood. Kidney biopsy, in addition to a widespread glycogen accumulation in proximal tubular epithelial cells, demonstrated medullary nephrocalcinosis. Screening for nephrocalcinosis may be warranted in pediatric patients with FBS, along with close surveillance of their kidney function.

Pediatric chest wall masses: spectrum of benign findings on ultrasound.

A palpable finding along the chest wall is a frequent indication for pediatric US. Accurate identification of benign lesions can reassure families and appropriately triage children who need follow-up, cross-sectional imaging, or biopsy. In this pictorial essay, we review chest wall anatomy, illustrate US techniques and discuss key US imaging features of common benign lesions and normal variants.

Epipericardial Fat Pad Necrosis-A Rare Cause of Chest Pain in an Adolescent.

ABSTRACT: Epipericardial fat necrosis is a rare cause of acute pleuritic chest pain reported in approximately 40 cases. This diagnosis mimics a myocardial infarction, pulmonary embolism, or pericarditis; however, the cardiac enzymes and electrocardiogram are usually normal. We present the first reported case of epipericardial fat necrosis in an adolescent.

Chondroid lipoma: multimodality imaging in a 9-year-old female.

Chondroid lipomas are rare, benign lipomatous tumors that occur most frequently in adults during the fourth decade of life. While a female predominance was observed in the initial series of 20 cases described in 1993, the subsequent 49 reported cases do not support a strong gender predilection. We report a case of a chondroid lipoma presenting in a 9-year-old female as a painless, enlarging, left gluteal mass. This is the second case to be reported in the first decade of life and the fourth pediatric case reported in the literature (age < 21). We review the imaging and pathology findings as well as present a comprehensive review of the current literature.

High-resolution rapid neonatal whole-body composition using 3.0 Tesla chemical shift magnetic resonance imaging.

BackgroundTo evaluate a whole-body rapid imaging technique to calculate neonatal lean body mass and percentage adiposity using 3.0 Tesla chemical shift magnetic resonance imaging (MRI).MethodsA 2-Point Dixon MRI technique was used to calculate whole-body fat and water images in term (n=10) and preterm (n=15) infants.ResultsChemical shift images were obtained in 42 s. MRI calculated whole-body mass correlated closely with measured body weight (R2=0.87; P<0.001). Scan-rescan analysis demonstrated a 95% limit of agreement of 1.3% adiposity. Preterm infants were born at a median of 25.7 weeks' gestation with birth weight 840 g. At term-corrected age, former preterm infants were lighter than term-born controls, 2,519 vs. 3,094 g regressing out age and group as covariates (P=0.005). However, this was not because of reduced percentage adiposity 26% vs. 24% (P=0.28). At term-corrected age, former preterm infants had significantly reduced lean body mass compared with that of term-born controls 1,935 vs. 2,416 g (P=0.002).ConclusionRapid whole-body imaging for assessment of lean body mass and adiposity in term and preterm infants is feasible, accurate, and repeatable. Deficits in whole-body mass in former preterm infants at term-corrected age are due to reductions in lean body mass not due to differences in adiposity.

Imaging and management of fetuses and neonates with alloimmune thrombocytopenia.

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is the most common cause of severe neonatal thrombocytopenia and intracranial bleeding in term newborns. Intracranial hemorrhage (ICH) commonly results in death or severe, lasting neurologic disability. The timing of ICH is also important for management of the next affected pregnancy in cases of FNAIT. This manuscript reviews the advantages and disadvantages of the different radiologic methodologies to identify and characterize ICH. It discusses the limits of ultrasound and the advantages of magnetic resonance imaging allowing avoidance of the radiation associated with computed tomography (CT) scans.

Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging.

BACKGROUND: The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. OBJECTIVE: To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. MATERIALS AND METHODS: A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. RESULTS: Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. CONCLUSION: Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between perforated and non-perforated cases. These results may help guide management decisions as MRI assumes a greater role in the work-up of pediatric appendicitis.

Diagnostic utility of intravenous contrast for MR imaging in pediatric appendicitis.

BACKGROUND: Magnetic resonance imaging (MRI) is increasingly employed as a diagnostic modality for suspected appendicitis in children. However, there is uncertainty as to which MRI sequences are sufficient for safe, timely and accurate diagnosis. Several recent studies have described different MRI protocols, including exams both with and without the use of intravenous contrast. OBJECTIVE: We hypothesized that intravenous contrast may be useful in some patients but could be safely omitted in others. MATERIALS AND METHODS: All MRI examinations (n=112) performed at our institution for evaluating appendicitis in children were retrospectively reevaluated. Exams were reread by pediatric radiologists under three conditions: With postcontrast images, Without postcontrast images, and Without/With - selective use of postcontrast sequences only when needed for diagnostic certainty. Samples were scored as positive, negative or equivocal for appendicitis. Findings were compared to pathological or clinical follow-up in the medical record. RESULTS: Without the use of intravenous contrast yielded more equivocal results (12.4%) compared to With contrast (3.4%). By selectively using postcontrast sequences, the Without/With group yielded fewer equivocal results (1.1%) compared to Without while also reducing contrast use 79.8% compared to the With contrast group. No significant differences in conditional sensitivity or conditional specificity were detected among the three groups. CONCLUSION: MRI diagnosis of acute appendicitis can be performed without contrast for most patients; injection of contrast can be reserved for only those patients with equivocal non-contrast imaging.

Non-invasive assessment of endothelial function in children with obesity and lipid disorders.

BACKGROUND: Digital tonometry is designed to non-invasively screen for endothelial dysfunction by the detection of impaired flow-induced reactive hyperaemia in the fingertip. We determined whether digital reactive hyperaemia correlated with risk factors for atherosclerosis in two groups of children at increased risk for endothelial dysfunction. METHODS: A total of 15 obese children and 23 non-obese, dyslipidaemic children, 8-21 years of age, were enrolled, and their medical histories, anthropometric measurements, carotid wall thickness by means of ultrasonography, and fasting blood samples for cardiovascular risk factors were obtained. The standard endoPAT index of digital reactive hyperaemia was modified to reflect the true peak response or the integrated response of the entire post-occlusion period. In each group, age, sex, pubertal status, carotid wall thickness, and multiple cardiovascular risk factors were tested as predictors of endothelial dysfunction. RESULTS: In the non-obese, dyslipidaemic group, but not in the obese group, both indices strongly correlated with height (r=0.55, p=0.007, by peak response) followed by weight, waist circumference, and age. In both groups, neither index of reactive hyperaemia significantly correlated with any other cardiovascular risk factor. CONCLUSIONS: Contrary to the known age-related increase in atherosclerosis, digital reactive hyperaemia increased with age and its correlates in non-obese, dyslipidaemic children and was not related to other cardiovascular risk factors in either group. The reason for the lack of this relationship with age in obese children is unknown. The age-dependent physiology of digital microvascular reactivity and the endothelium-independent factors controlling the peak hyperaemic response need further study in children with a wide age range.

Longitudinal diffusion-weighted imaging changes in children with small bowel Crohn's disease: preliminary experience.

PURPOSE: Crohn's disease has been associated with restricted diffusion in diseased small bowel segments on diffusion-weighted imaging (DWI). However, data addressing longitudinal changes in DWI findings and their potential clinical ramifications in the pediatric population are lacking. The purpose of this study was to follow DWI changes in diseased small bowel segments between serial magnetic resonance enterography (MRE) examinations, and to correlate these changes with other imaging parameters and clinical status. METHODS: This retrospective study evaluated patients less than 21 years of age undergoing serial MRE examinations including DWI for Crohn's disease involving the small bowel. All patients carried a diagnosis of Crohn's disease established by pathology or corroborative clinical and imaging findings. Longitudinal changes in mean apparent diffusion coefficient (ADC) values within the wall of affected small bowel lesions were recorded and normalized to both unaffected bowel and skeletal muscle. ADC changes were correlated with qualitative imaging phenotype, as reflected by a defined set of non-DWI imaging parameters, as well as with clinical disease activity. RESULTS: Seventeen lesions were evaluated longitudinally, distributed among 13 patients (9 boys and 4 girls, mean age at baseline 16.6 years), each of whom had two sequential MRE examinations. Lesions demonstrating a fibrostenotic imaging phenotype at follow-up MRE had a significantly lower change in mean ADC value between examinations than lesions that did not have a fibrostenotic imaging phenotype (p = 0.0005), an effect that persisted when ADC values were normalized to unaffected bowel and skeletal muscle. Across all studies, lesions with a fibrostenotic imaging phenotype had lower ADC values than those with an inflammatory imaging phenotype, which were in turn lower than those with a normal imaging phenotype (p = 0.0001). CONCLUSION: Patterns of longitudinal DWI changes in Crohn's disease may differ among small bowel lesions depending upon their specific natural histories. These findings may assist in the evaluation of the ADC value as a potential imaging surrogate when evaluating lesion status, particularly as it pertains to relative contributions of inflammation and fibrosis.

Intracranial calcifications and hemorrhages: characterization with quantitative susceptibility mapping.

PURPOSE: To compare gradient-echo (GRE) phase magnetic resonance (MR) imaging and quantitative susceptibility mapping (QSM) in the detection of intracranial calcifications and hemorrhages. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board. Thirty-eight patients (24 male, 14 female; mean age, 33 years ± 16 [standard deviation]) with intracranial calcifications and/or hemorrhages diagnosed on the basis of computed tomography (CT), MR imaging (interval between examinations, 1.78 days ± 1.31), and clinical information were selected. GRE and QSM images were reconstructed from the same GRE data. Two experienced neuroradiologists independently identified the calcifications and hemorrhages on the QSM and GRE phase images in two randomized sessions. Sensitivity, specificity, and interobserver agreement were computed and compared with the McNemar test and k coefficients. Calcification loads and volumes were measured to gauge intermodality correlations with CT. RESULTS: A total of 156 lesions were detected: 62 hemorrhages, 89 calcifications, and five mixed lesions containing both hemorrhage and calcification. Most of these lesions (146 of 151 lesions, 96.7%) had a dominant sign on QSM images suggestive of a specific diagnosis of hemorrhage or calcium, whereas half of these lesions (76 of 151, 50.3%) were heterogeneous on GRE phase images and thus were difficult to characterize. Averaged over the two independent observers for detecting hemorrhages, QSM achieved a sensitivity of 89.5% and a specificity of 94.5%, which were significantly higher than those at GRE phase imaging (71% and 80%, respectively; P < .05 for both readers). In the identification of calcifications, QSM achieved a sensitivity of 80.5%, which was marginally higher than that with GRE phase imaging (71%; P = .08 and .10 for the two readers), and a specificity of 93.5%, which was significantly higher than that with GRE phase imaging (76.5%; P < .05 for both readers). QSM achieved significantly better interobserver agreements than GRE phase imaging in the differentiation of hemorrhage from calcification (κ: 0.91 vs 0.55, respectively; P < .05). CONCLUSION: QSM is superior to GRE phase imaging in the differentiation of intracranial calcifications from hemorrhages and with regard to the sensitivity and specificity of detecting hemorrhages and the specificity of detecting calcifications.

Importance of MRI in the diagnosis of vertebral involvement in generalized cystic lymphangiomatosis.

A 9-year-old boy presented with the sudden onset of pleuritic chest pain and on CT was found to have a large pleural effusion, mediastinal fluid, splenic lesions and multiple apparently sclerotic vertebral bodies. Subsequent MRI showed that those vertebral bodies that appeared sclerotic were in fact normal, and the vertebral bodies initially interpreted as normal had an abnormal T1 and T2 hyperintense signal on MRI and were relatively lucent on CT. MRI also demonstrated abnormal heterogeneous T2 hyperintense paraspinal tissue and several multicystic soft tissue masses. Biopsy of two adjacent vertebral bodies, one relatively sclerotic and one lucent, demonstrated findings of bony remodeling without a specific diagnosis. Biopsy of an infiltrative mediastinal mass confirmed the diagnosis of generalized cystic lymphangiomatosis. MRI should be included in the assessment of vertebral involvement in this condition because CT and biopsy findings may be nonspecific.

Imaging features, classification and clinical features of intrahepatic congenital portosystemic shunts.

Congenital portosystemic shunts (CPSS) are a rare developmental anomaly diverting blood flow from the portal venous system and the liver to the systemic venous system. This case series examines the sonographic imaging findings, shunt classification, ultrasound shunt ratios, and outcomes in nine children (5 females, 4 males) admitted to our institution between 2015 and 2022 were included in this study. The shunts were initially categorized by the Parks classification and were followed by serial ultrasounds. Clinical presentation, clinical course, laboratory data, shunt ratios, and time to shunt closure were all followed on subsequent ultrasounds. The most common type of CPPS was the Type 3 shunt. In cases where shunt ratios were measured, the shunt ratio gradually decreased in tandem with decreasing ammonia levels until spontaneous closure was achieved. Predictors of lack of shunt closure included high shunt ratios and Type 4 shunts. Patients with CPPS can be followed with the shunt ratio calculation obtained from sonographic imaging, which may correlate to ammonia levels and indicate risk of hepatic encephalopathy as well as predict speed and timing of closure.

Intramuscular nodular fasciitis of the rectus abdominis muscle in an 11-year-old girl.

Nodular fasciitis is a benign rapidly proliferating fibrous tumor that is common in adults but relatively uncommon in children. When present in children, nodular fasciitis is typically subcutaneous in location and involves the head and neck. We present a case of intramuscular nodular fasciitis involving the rectus abdominis muscle in an 11-year-old girl and discuss the importance of distinguishing this rare but benign lesion from a more aggressive sarcomatous process.

Visualization of the normal appendix with MR enterography in children.

BACKGROUND: Magnetic resonance (MR) imaging may provide a radiation-sparing alternative to CT in diagnosing appendicitis in children in whom US is equivocal. However, comparability with CT in the detection of the appendix remains to be established. OBJECTIVE: To determine the detection rate of the normal appendix in children on oral and IV contrast-enhanced MRI. METHODS: MR imaging of 58 patients who had previously undergone MR enterography was retrospectively reviewed. Detection rate, body mass index, age and gender were recorded. RESULTS: The normal appendix was detected in 28 cases (48%), with greatest detection rate on the axial fast imaging employing steady-state acquisition (FIESTA) sequence. Children in whom the appendix was detected had significantly higher BMI compared to children in whom the appendix was not seen. Neither age nor gender demonstrated a significant association with detection rate. CONCLUSION: The detection rate of the normal appendix in children on oral and IV contrast-enhanced MRI was 48%, which is comparable to detection rates on CT, as well as to previously reported detection rates on MR imaging with neither oral nor IV contrast agents. These findings may serve to guide the development of MRI protocols for pediatric appendicitis.

Parsonage-turner syndrome associated with SARS-CoV2 (COVID-19) infection.

Parsonage-Turner Syndrome (PTS), also known as idiopathic brachial plexopathy or neuralgic amyotrophy, is an uncommon condition characterized by acute onset of shoulder pain, most commonly unilateral, which may progress to neurologic deficits such as weakness and paresthesias (Feinberg and Radecki, 2010 [1]). Although the etiology and pathophysiology of PTS remains unclear, the syndrome has been reported in the postoperative, postinfectious, and post-vaccination settings, with recent viral illness reported as the most common associated risk factor (Beghi et al., 1985 [2]). Various viral, bacterial, and fungal infections have been reported to precede PTS, however, currently there are no reported cases of PTS in the setting of recent infection with SARS-CoV2 (COVID-19). We present a case of a 17 year old female patient with no significant past medical or surgical history who presented with several weeks of severe joint pain in the setting of a recent viral illness (SARS-CoV2, COVID-19). MRI of the left shoulder showed uniform increased T2 signal of the supraspinatus, infraspinatus, teres minor, teres major, and trapezius muscles, consistent with PTS. Bone marrow biopsy results excluded malignancy and hypereosinophilic syndrome as other possible etiologies. Additional rheumatologic work-up was also negative, suggesting the etiology of PTS in this patient to be related to recent infection with SARS-CoV2 (COVID-19). Radiologists should be aware of this possible etiology of shoulder pain as the number of cases of SARS-CoV2 (COVID-19) continues to rise worldwide.

Pulmonary blastoma in a neonate: a lesion distinct from pleuropulmonary blastoma with unique cytogenetic features.

Pulmonary blastoma is a rare malignant primary lung neoplasm typically seen in adults that accounts for 0.3-1.3% of lung malignancies. It has been categorized as a subtype of sarcomatoid carcinoma according to the current World Health Organization Classification of Lung Tumours and is distinct from the more common pediatric lung tumor pleuropulmonary blastoma. We report a case of neonatal pulmonary blastoma, illustrating the imaging characteristics of this rare tumor. The subject of pediatric lung masses is confusing because the terms pleuropulmonary blastoma and pulmonary blastoma have been used interchangeably in previously reported cases. We recommend use of the current WHO classification to differentiate these lesions as additional cases are described. Additionally, we discuss distinctive cytogenetic features of this case.