The Society for Pediatric Radiology Magnetic Resonance Imaging and Emergency and Trauma Imaging Committees' consensus protocol recommendation for rapid MRI for evaluating suspected appendicitis in children.

The imaging evaluation of acute abdominal pain in children with suspected appendicitis has evolved to include rapid abdominopelvic MRI (rMRI) over recent years. Through a collaborative effort between the Magnetic Resonance Imaging (MRI) and Emergency and Trauma Imaging Committees of the Society for Pediatric Radiology (SPR), we conducted a survey on the utilization of rMRI to assess practice specifics and protocols. Subsequently, we present a proposed consensus rMRI protocol derived from the survey results, literature review, and discussion and consensus between committee members.

Respiratory-Triggered Flow-Independent Noncontrast Non-ECG-Gated MRV (REACT) Versus CE-MRV for Central Venous Evaluation in Children and Young Adults: A Six-Reader Study.

BACKGROUND. Contrast-enhanced MRI is commonly used to evaluate thoracic central venous patency in children and young adults. A flow-independent noncontrast non-ECG-gated 3D MRA-MR venography (MRV) technique described in 2019 as "relaxation-enhanced angiography without contrast and triggering (REACT)" may facilitate such evaluation. OBJECTIVE. The purpose of our study was to compare image quality, diagnostic confidence, and interreader agreement between respiratory-triggered REACT and 3D Dixon-based contrast-enhanced MRV (CE-MRV) for evaluating thoracic central venous patency in children and young adults. METHODS. This retrospective study included 42 consecutive children and young adults who underwent MRI of the neck and chest to evaluate central venous patency between August 2019 and January 2021 (median age, 5.2 years; IQR, 1.4-15.1 years; 22 female patients and 20 male patients). Examinations included respiratory-triggered REACT and navigator-gated CE-MRV sequences based on the institution's standard-of-care protocol. Six pediatric radiologists from four different institutions independently reviewed REACT and CE-MRV sequences; they assessed overall image quality (scale, 1-5; 5 = excellent), diagnostic confidence (scale, 1-5; 5 = extremely confident), and presence of clinically relevant artifact(s). Readers classified seven major central vessels as normal or abnormal (e.g., narrowing, thrombosis, or occlusion). Analysis used Wilcoxon signed rank and McNemar tests and Fleiss kappa coefficients. RESULTS. The distribution of overall image quality scores was higher (p = .02) for REACT than for CE-MRV for one reader (both sequences: median score, 5). Image quality scores were not significantly different between the sequences for the remaining five readers (all p > .05). Diagnostic confidence scores and frequency of clinically relevant artifact(s) were not significantly different between sequences for any reader (all p > .05). Interreader agreement for vessel classification as normal or abnormal was similar between sequences for all seven vessels (REACT: κ = 0.37-0.81; CE-MRV: κ = 0.34-0.81). Pooling readers and vessels, 65.4% of vessels were normal by both sequences; 18.7%, abnormal by both sequences; 9.8%, abnormal by REACT only; and 6.1%, abnormal by CE-MRV only. CONCLUSION. Respiratory-triggered REACT, in comparison with CE-MRV, showed no significant difference in image quality (aside from for one of six readers), diagnostic confidence, or frequency of artifact(s), with similar interreader agreement for vessel classification as normal or abnormal. CLINICAL IMPACT. High-resolution 3D MRV performed without IV contrast material can be used to assess central venous patency in children and young adults.

Pediatric mediastinal masses.

Mediastinal masses are categorized based on the International Thymic Malignancy Interest Group (ITMIG) classification into prevascular, visceral and paravertebral compartments. The schema is based on cross-sectional imaging, mainly CT, and helps with generating a differential diagnosis based on location of the mass. Up to half of all pediatric mediastinal tumors are malignant. In this review we describe mediastinal masses that are relevant to the pediatric population, as well as the role of MR imaging of mediastinal masses and its advantages.

Utilization of neonatal sedation and anesthesia: an SPR survey.

BACKGROUND: There is little data regarding the use of sedation and anesthesia for neonatal imaging, with practice patterns varying widely across institutions. OBJECTIVE: To understand the current utilization of sedation and anesthesia for neonatal imaging, and review the current literature and recommendations. MATERIALS AND METHODS: One thousand, two hundred twenty-six questionnaire invitations were emailed to North American physician members of the Society for Pediatric Radiology using the Survey Monkey platform. Descriptive statistical analysis of the responses was performed. RESULTS: The final results represented 59 institutions from 26 U.S. states, the District of Columbia and three Canadian provinces. Discrepant responses from institutions with multiple respondents (13 out of 59 institutions) were prevalent in multiple categories. Of the 80 total respondents, slightly more than half (56%) were associated with children's hospitals and 44% with the pediatric division of an adult radiology department. Most radiologists (70%) were cognizant of the neonatal sedation policies in their departments. A majority (89%) acknowledged awareness of neurotoxicity concerns in the literature and agreed with the validity of these concerns. In neonates undergoing magnetic resonance imaging (MRI), 46% of respondents reported attempting feed and bundle in all patients and an additional 46% attempt on a case-by-case basis, with most (35%) using a single swaddling attempt before sedation. Sedation was most often used for neonatal interventional procedures (93%) followed by MR (85%), nuclear medicine (48%) and computed tomography (31%). More than half of respondents (63%) reported an average success rate of greater than 50% when using neonatal sedation for MR. CONCLUSION: Current practice patterns, policies and understanding of the use of sedation and anesthesia for neonatal imaging vary widely across institutions in North America, and even among radiologists from the same institution. Our survey highlights the need for improved awareness, education, and standardization at both the institutional level and the societal level. Awareness of the potential for anesthetic neurotoxicity and success of non-pharmacologic approaches to neonatal imaging is crucial, along with education of health care personnel, systematic approaches to quality control and improvement, and integration of evidence-based protocols into clinical practice.

Magnetic resonance imaging in children with implants.

As access to MRI in pediatrics increases, the radiologist needs to become acquainted with the basic principles of MRI safety. As part of the image acquisition, the static magnetic field, gradient system, and the radiofrequency transmit-receive coil interact with medical and non-medical implants and can result in serious injury. The main stage of risk triage is based on the determination of whether the implant is MRI-safe, conditional, unsafe or unknown. Guiding principles include the strict adherence to manufacturer specifications for MRI-conditional implants and the assumption that an unknown implant is MR-unsafe. In this article we review considerations for common medical implants encountered in pediatrics including ventriculoperitoneal shunts, orthopedic hardware, orthodontic hardware, pacemakers, vascular stents, vagal nerve stimulators and cochlear implants. Finally, we review a set of high-yield considerations, including the non-communicative patient (sedated or non-verbal), susceptibility artifacts from unclear source, and the approach to an unknown implant.

320 Slice CT in Imaging of Congenital Heart Diseases in Infants: A Single-Center Experience.

Objective The study was conducted to evaluate the best possible imaging technique for neonatal cardiac imaging including optimal injection techniques, intravenous line placement, expected radiation dose, and need for sedation while performing the study on a 320 slice Toshiba® Aquilion ONE® scanner. Study results can be used to optimize imaging parameters for maximum clinical yield. We provide representative images of our cases. Methodology Cardiac CTs performed on infants less than one year of age at the time of study were evaluated. Data collection included radiation dose, duration of the scan, heart rate, type and route of contrast injection, need for sedation or general anesthesia and quality of study including image contrast and motion artifacts. Results Average age of infants at the time of scan was approximately two months. Prospectively gated volumetric scans performed within one heartbeat with a single gantry turn formed the majority of studies. Average effective dose was below 1 mSv. Several patients were scanned without any sedation. Most studies were deemed diagnostic and of superior quality on a 4-point scale. Qualitative image analysis revealed an excellent intraclass correlation between two raters. Conclusion Parameters needed for successfully performing cardiac CTs with a high degree of diagnostic quality in neonates were identified. For infants below a year hand injection of Isovue 300 in a 24 G peripheral upper extremity IV line with real-time contrast bolus monitoring and manual start to scanning is adequate when being scanned on a 320 slice Volumetric scanner with prospective auto-target EKG gating. Sedation may not be necessary for infants when wrap and feed techniques and free breathing are employed. Radiation doses utilizing this technique were uniformly low.

Magnetic resonance imaging quality control, quality assurance and quality improvement.

Quality in MR imaging is a comprehensive process that encompasses scanner performance, clinical processes for efficient scanning and reporting, as well as data-driven improvement involving measurement of key performance indicators. In this paper, the authors review this entire process. This article provides a framework for establishing a successful MR quality program. The collective experiences of the authors across a spectrum of pediatric hospitals is summarized here.

Cranial Suture Evaluation on Routine Pediatric MRI.

PURPOSE: The efficacy of magnetic resonance imaging (MRI) for evaluating sutures has not been well studied. CT with 3-dimensional reformats is currently the preferred modality for imaging the major cranial sutures. The role of MRI is primarily is for evaluating the brain for any concurrent malformations. Our objective was to evaluate the reliability of MRI when compared to CT for evaluation of cranial sutures. METHODS: A list of 500 consecutive patients who underwent an MRI as well as a CT study was obtained. Studies were done between January 2011 and December 2016. The inclusion criteria required the 2 studies to be performed within 3 months of each other. All MRI studies were reviewed by a pediatric neuroradiologist to determine whether the sagittal, coronal, and lambdoid sutures were patent, fused or could not be assessed with confidence. In cases where a confident determination could not be made, the studies were reviewed with another pediatric neuro-radiologist and a decision made in concurrence. The CT scans were then evaluated in a similar fashion, after the MRI review was completed. The CT and MRI results were then compared to determine the accuracy of the MRI in assessing the sutures. RESULTS: Mean age of the studied children was 8.54 years. Seventy-two percent of the sagittal sutures were seen. When seen the sagittal suture was correctly identified in 98% of cases as either fused or patent. The lambdoid suture was seen in 94.3% of studies and was correctly designated as patent or fused in 99.6% of that subset of cases. The coronal suture was seen in 66.3% of the cases and when seen was always (100%) correctly designated. The probability of agreement between MRI and CT increased with age. The probability of sutures which were not seen decreased with age. The false negative and positives remained low for all ages. CONCLUSIONS: MRI is a viable tool for detection of cranial sutures. The 3-dimensional T1 Weighted sequence was particularly useful in suture evaluation. Although the visibility of sutures is inferior to that on a CT scan, if detected, the accuracy scan is fairly accurate in establishing fusion vs patency. It should be a part of routine surveillance on every pediatric neuro MRI study given the neurocognitive implications of incidental sutural synostosis.

Fetal MR imaging in urogenital system anomalies.

Fetal magnetic resonance imaging (MRI) is an important adjunct to ultrasound in evaluation of fetal urogenital system. While, ultrasound remains the primary modality, MRI helps in more complicated cases or where ultrasound is limited due to technical factors such as poor acoustic window. The goal of this article is to review the common fetal urogenital anomalies and their imaging manifestations on ultrasound and MRI, and discuss how MRI adds diagnostic value.

Congenital intestinal hypoganglionosis: A radiologic mimic of Hirschsprung's disease.

Intestinal hypoganglionosis or isolated hypoganglionosis is a rare entity with a clinical and radiologic presentation that can mimic Hirschsprung's disease in the neonatal period. The diagnosis of this entity can be challenging with suction rectal biopsies that are standard for diagnosing Hirschsprung's disease. We present this case of congenital intestinal hypoganglionosis detailing the neonatal course, due to its rarity and the conundrums faced before an eventual diagnosis could be rendered. This case also illustrates the role of full thickness rectal biopsy in selected cases such as ours where the radiologic features are typical of Hirschsprung's, despite negative suction biopsies.

Unusual case of recurrent SMART (stroke-like migraine attacks after radiation therapy) syndrome.

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a rare delayed complication of cerebral radiation therapy. A 53-year-old female initially presented with headache, confusion and left homonymous hemianopia. Her medical history was notable for cerebellar hemangioblastoma, which was treated with radiation in 1987. Her initial brain MRI (magnetic resonance imaging) revealed cortical enhancement in the right temporo-parieto-occipital region. She improved spontaneously in 2 weeks and follow-up scan at 4 weeks revealed no residual enhancement or encephalomalacia. She presented 6 weeks later with aphasia. Her MRI brain revealed similar contrast-enhancing cortical lesion but on the left side. Repeat CSF studies was again negative other than elevated protein. She was treated conservatively and recovered completely within a week. Before diagnosing SMART syndrome, it is important to rule out tumor recurrence, encephalitis, posterior reversible encephalopathy syndrome (PRES) and stroke. Typically the condition is self-limiting, and gradually resolves.

Respiratory motile cilia dysfunction in a patient with cranioectodermal dysplasia.

Ciliopathies such as cranioectodermal dysplasia, Sensenbrenner syndrome, short-rib polydactyly, and Jeune syndrome are associated with respiratory complications arising from rib cage dysplasia. While such ciliopathies have been demonstrated to involve primary cilia defects, we show motile cilia dysfunction in the airway of a patient diagnosed with cranioectodermal dysplasia. While this patient had mild thoracic dystrophy not requiring surgical treatment, there was nevertheless newborn respiratory distress, restrictive airway disease with possible obstructive airway involvement, repeated respiratory infections, and atelectasis. High-resolution videomicroscopy of nasal epithelial biopsy showed immotile/dyskinetic cilia and nasal nitric oxide was reduced, both of which are characteristics of primary ciliary dyskinesia, a sinopulmonary disease associated with mucociliary clearance defects due to motile cilia dysfunction in the airway. Exome sequencing analysis of this patient identified compound heterozygous mutations in WDR35, but no mutations in any of the 30 known primary ciliary dyskinesia genes or other cilia-related genes. Given that WDR35 is only known to be required for primary cilia function, we carried out WDR35 siRNA knockdown in human respiratory epithelia to assess the role of WDR35 in motile cilia function. This showed WDR35 deficiency disrupted ciliogenesis in the airway, indicating WDR35 is also required for formation of motile cilia. Together, these findings suggest patients with WDR35 mutations have an airway mucociliary clearance defect masked by their restrictive airway disease.

Vasogenic edema characterizes pediatric acute disseminated encephalomyelitis.

INTRODUCTION: MR imaging criteria for diagnosing acute disseminated encephalomyelitis (ADEM) have not been clearly established. Due to the wide spectrum of differential considerations, new imaging features allowing early and accurate diagnosis for ADEM are needed. We hypothesized that ADEM lesions would be characterized by vasogenic edema due to the potential reversibility of the disease. METHODS: Sixteen patients who met the diagnostic criteria for ADEM proposed by the International Pediatric Multiple Sclerosis Study Group (IPMSSG) and had complete MR imaging studies performed at our institution during the acute phase of the disease were identified retrospectively and evaluated by experienced pediatric neuroradiologists. RESULTS: Vasogenic edema was demonstrated on diffusion-weighted imaging (DWI) and corresponding apparent diffusion coefficient (ADC) maps in 12 out of 16 patients; cytotoxic edema was identified in two patients while the other two patients displayed no changes on DWI/ADC. ADC values for lesions and normal-appearing brain tissue were 1.39 ± 0.45 × 10(-3) and 0.81 ± 0.09 × 10(-3) mm/s(2), respectively (p=0.002). When considering a cutoff of 5 days between acute and subacute disease, no difference between ADC values in acute vs. subacute phase was depicted. However, we found a significant correlation and an inverse and significant relationship between time and ADC value. CONCLUSION: We propose that vasogenic edema is a reliable diagnostic sign of acute neuroinflammation in ADEM.

Comparison of simulated cone beam computed tomography to conventional helical computed tomography for imaging of rhinosinusitis.

OBJECTIVES/HYPOTHESIS: Cone beam computed tomography (CBCT) has emerged as a low radiation dose alternative to traditional computed tomography (CT) to evaluate the paranasal sinuses. The purpose of our study was to determine how often clinically important findings would be missed if CBCT was used routinely for sinus imaging. STUDY DESIGN: Retrospective review. METHODS: We evaluated all maxillofacial CT scans performed for sinusitis over a 1-year period. The original multidetector CT (MDCT) images were reviewed retrospectively. A theoretical CBCT was then created from the original study utilizing only the bone algorithm images and separately reviewed. We calculated the proportion of abnormal findings that were identified on the MDCT but would have been missed by the theoretical CBCT, and reviewed the medical record to determine which potentially missed findings would have changed management. Radiation dose from the MDCT scanners was calculated and compared to published dose estimates for the paranasal sinuses on CBCT. RESULTS: Maxillofacial CTs from 361 consecutive patients were included, of which 12 (3.3%) demonstrated findings that would have been missed on the theoretical CBCT. Of those, four (1.1%) would have resulted in a change in management. Effective radiation dose for our scanners ranged from 0.67 mSv to 2.15 mSv, compared to a published estimated dose of 0.2 mSV for CBCT. CONCLUSIONS: In the majority of patients undergoing simulated CBCT for evaluation of sinusitis, incidental findings of soft-tissue disease were rare. With appropriate selection of patients, CBCT can offer substantial radiation dose reduction and may provide a viable alternative to standard MDCT sinus imaging protocols.

Brachium pontis stroke revealing neurofibromatosis type-2.

NF2 is an autosomal dominant disorder with neuroectodermal dysplasia. Most patients present with characteristic clinical tumors during or beyond the adolescent age group. The diagnosis is mainly clinical. Vasculopathy is rarely associated with NF2. Vascular complication as the presenting symptom in NF-2 is unknown. We report a case of a 2-year-old child with no prior family history of neurofibromatosis presenting with ataxia and brain-stem stroke.

Reversible cytotoxic edema in TPN-related hepatic encephalopathy.

Hepatic encephalopathy (HE) is an uncommon complication of total parenteral nutrition (TPN). Cytotoxic edema has not been reported in children with TPN-related HE. We describe a case of TPN-related HE presenting with diffuse cytotoxic edema which reversed after liver transplantation.