Imaging of the Pediatric Knee.

During normal development, imaging findings in the immature knee joint may mimic pathology or indicate transient sites of weakness, prone to injury. This article reviews the development of the knee joint, age- and maturation-dependent imaging considerations, and various developmental variants that can be encountered, subdivided into those that involve the tibiofemoral and patellofemoral compartments, soft tissues, and osseous components. The tibiofemoral compartment section reviews the focal periphyseal edema zone (FOPE), ossification variants of the femoral condyles, distal femoral metaphyseal cortical irregularity from periosteal traction, and the metaphyseal subperiosteal stripe, which should be distinguished from pathologic mimickers such as endochondral ossification dysfunction, osteochondritis dissecans (OCD), fibroosseous lesion, periosteal and subcortical pathologies. The patellofemoral compartment section includes a review of partite patella, dorsolateral defect, variant trochlear morphology, and maturation-dependent sites of transient weakness that are prone to injury from repetitive overuse (Sinding-Larsen-Johansson syndrome and Osgood-Schlatter disease) and avulsion fractures (patellar sleeve and tibial tubercle avulsions). Finally, soft tissue (discoid lateral meniscus, meniscal flounce, anterior cruciate ligament variants) and osseous components (meniscal ossicle, fabella, and cyamella) are reviewed.

Children With Elbow Injuries and Sonographic Elevated Posterior Fat Pad but No Identifiable Posterior Fat Pad on Lateral Radiographs: A Case Series.

Point of Care Ultrasound (POCUS) is used to evaluate the injured pediatric elbow. Standard of care, however, remains radiography. POCUS performed in the setting of normal radiographs have been obtained may demonstrate radiologic occult lipohemarthrosis indicative of occult fracture. We reviewed our pediatric emergency department (PED) POCUS archive for lipohemarthrosis, and then isolated those cases with normal elbow radiography. Radiography was deemed to be normal per the interpretation of the treating PED physician, and was reviewed for this series by an experienced ABR board certified pediatric radiologist. Fracture on POCUS was defined as fracture line or lipohemarthrosis in a posterior sagittal or transverse view of the distal humerus. Fracture was confirmed by signs of cortical healing on follow-up radiography, or clinical course consistent with fracture as documented by an orthopedist. We identified four children with elbow fractures who had no fracture line or elevated posterior fat pad on radiography but demonstrated lipohemarthrosis on POCUS. POCUS may elicit evidence of fracture even after normal radiography, and POCUS findings suggesting occult fracture may allow for more effective guidance on discharge.

Use of Point-of-Care Ultrasound to Identify Occult Fractures of the Tibia in the Pediatric Emergency Department: A Case Series.

BACKGROUND: Although point-of-care ultrasound (POCUS) has been shown to be useful in the identification of both pediatric and adult long-bone fractures in the emergency setting, radiography remains the standard of care. Emergency physicians are often faced with the dilemma of how to evaluate and treat the child with lower leg injury and physical examination concerning for fracture but no readily identifiable fracture line on radiography. CASE REPORTS: We present four cases in which POCUS was used to diagnose a radiographically occult fracture of the proximal tibia in young children. This is the first case series of occult fracture of the tibia diagnosed with POCUS. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: POCUS can demonstrate evidence of fracture even after unremarkable radiography is obtained, and POCUS findings consistent with fracture might allow for more effective guidance on discharge.

Therapeutic Computed Tomography-Guided Pericardiocentesis: Lessons Learned Based on a 7-Year Single-Center Experience.

OBJECTIVE: Pericardiocentesis is a well-known procedure commonly performed by either image-guided intervention or surgical approaches. Computed tomography (CT)-guided pericardiocentesis is not widely used, but provides certain advantages. In the article we will discuss our technique of CT-guided therapeutic pericardiocentesis, including advantages and disadvantages, patient selection, possible approaches, and complications. METHODS: The retrospective study included 121 therapeutic pericardial drainages performed under CT guidance. Demographic data of the patients, entry site, and needle orientation were recorded. Procedure complications and their significance were analyzed. RESULTS: One hundred and twenty-one pericardial drainages with catheter insertion were performed under CT guidance on 119 patients presenting with clinically significant pericardial effusion. The most common approach was at the left anterior chest wall. The rate of minor complications was 5.8%, no major complications occurred. CONCLUSIONS: Therapeutic pericardiocentesis can be obtained under CT guidance in a safe and effective manner. Recommendations for building a patient-centered protocol with an interdisciplinary team are discussed. Patient selection, procedural guidance, and lessons to avoid complications are reviewed.

Feasibility study of a novel portable digital radiography system modified for fluoroscopy in the neonatal intensive care unit.

BACKGROUND: A portable radiographic system capable of fluoroscopic imaging in the neonatal intensive care unit (NICU) potentially benefits critically ill neonates by eliminating the need to transport them to a fluoroscopy suite. OBJECTIVE: To evaluate whether a portable bedside fluoroscopy system in the NICU can deliver comparable image quality at a similar dose rate to a standard system in a fluoroscopy suite. MATERIALS AND METHODS: In phase A, 20 patients <3 years of age and scheduled to undergo upper gastrointestinal series (upper GI) or voiding cystourethrograms (VCUG) in the radiology fluoroscopy suite were recruited to evaluate a portable fluoroscopic unit. A modified portable radiographic system with a cassette-sized detector and an in-room fluoroscopy system were sequentially used in the same examination. Four radiologists compared the image quality of 20 images from each system using the Radlex score (1-4) for five image quality attributes. The radiation dose rates for the portable and in-suite systems were collected. In phase B, fluoroscopy studies were performed in 5 neonates in the NICU and compared to the 20 previous neonatal studies performed in the department. Clinical workflow, examination time, fluoroscopy time, scattered radiation dose and patient radiation dose were evaluated. RESULTS: In phase A, average dose rates for in-room and portable systems were equivalent, (0.322 mGy/min and 0.320 mGy/min, respectively). Reader-averaged Radlex scores for in-room and portable systems were statistically significantly greater (P<0.05) for all attributes on the portable system except for image contrast. In phase B, scattered radiation from the average fluoroscopy time (26 s) was equivalent to the scattered radiation of 2.6 portable neonatal chest radiographs. Procedure time and diagnostic quality were deemed equivalent. The average dose rate in the NICU with the portable system was 0.21 mGy/min compared to 0.29 mGy/min for the in-room system. CONCLUSION: The portable fluoroscopy unit is capable of providing comparable image quality at equivalent dose levels to an in-room system for neonates with minimal risks to the staff and other patients in the NICU.

Adapting Surgical Clerkship Curricula in Response to the COVID-19 Pandemic.

BACKGROUND: Coronavirus disease-19 (COVID-19) impacted medical education and led to the significant modification or suspension of clinical clerkships and rotations. OBJECTIVES: To describe a revised surgery clerkship curriculum, in which we divided in-person clinical teaching into smaller groups of students and adopted online-based learning to foster student and patient safety while upholding program standards. METHODS: The third-year surgery core clerkship of a 4-year international English-language program at the Medical School for International Health at Ben Gurion University of the Negev, Beer Sheva, Israel, was adapted by dividing students into smaller capsules for in-person learning and incorporating online learning tools. Specifically, students were divided evenly throughout three surgical departments, each of which followed a different clinical schedule. RESULTS: National Board of Medical Examiners clerkship scores of third-year medical students who were returning to in-person clinical clerkships after transitioning from 8 weeks of online-based learning showed no significant difference from the previous 2 years. CONCLUSIONS: To manage with the restrictions caused by COVID-19 pandemic, we designed an alternative approach to a traditional surgical clerkship that minimized the risk of exposure and used online learning tools to navigate scheduling challenges. This curriculum enabled students to complete their clinical rotation objectives and outcomes while maintaining program standards. Furthermore, this approach provided a number of benefits, which medical schools should consider adopting the model into practice even in a post-pandemic setting.

Radiographic overlap of recurrent Caffey disease and chronic recurrent multifocal osteomyelitis (CRMO) with considerations of molecular origins.

Caffey disease, or infantile cortical hyperostosis, classically describes a self-limited inflammatory disorder that presents in the infant with fussiness, focal swelling and sometimes fever. Imaging is conventionally limited to radiography, which shows mild to profound subperiosteal bone formation and sometimes deformity. This disease was not uncommonly diagnosed in the late 20th century. Interestingly, the disease may not just occur in the infant, and it may be due to a genetic mutation in the alpha-one chain of type 1 collagen (COL1A1). Recurrent or delayed onset in the older child or adolescent also occurs. In more recent years, another type of inflammatory bone disorder, chronic sterile osteomyelitis, has been frequently recognized and, depending on the radiographic stage or the diagnostic modality used, may have characteristics overlapping with Caffey disease. In this review, we discuss the demographics, imaging and known etiologies for Caffey disease and chronic recurrent multifocal osteomyelitis and raise the possibility of similar molecular origins.

Remote pathology education during the COVID-19 era: Crisis converted to opportunity.

CONTEXT: The COVID-19 pandemic led to shutting of education faculties, including clinical clerkships for medical students. OBJECTIVE: To review a selective for a course in diagnostic pathology geared toward undergraduate medical students, including its design, technical implementation, instructor and student evaluations, and suggestions for options for further adjusting and optimizing the selective. DESIGN: Whole slide images (WSI) were anonymized and students were given remote access to university computers, which were prepared with two freely available WSI viewers. Each topic was taught in a four-part module: Self-assigned reading, lecture via Zoom, quiz based on digital slide sets, and a frontal review of the slides via Zoom. Fifty-nine students participated in the selective. Following the course, students completed an anonymous questionnaire. RESULTS: Of the 59 participants, 42% (n = 25) responded. None of the respondents had any previous instruction in diagnostic pathology. Overall, the course was rated very favorably: 68% (n = 17) gave at least 3 points on a 4-point scale on questions relating to course interest, improvement in understanding of the covered diseases, and how strongly they would recommend a student take this course if given an option. The most significant disadvantage of the class, as reported by 80% (n = 20) were technical challenges in accessing the slides. CONCLUSION: We believe the course was a success and can be a model for future virtual pathology electives. Great effort should be done to provide technical support to the students. The selective demonstrated value for students and provided much-needed exposure to diagnostic pathology in clinical practice.

Management of Intussusception in the Pediatric Emergency Department: Risk Factors for Recurrence.

BACKGROUND: The standard treatment for intussusception is air reduction enema (ARE) with inpatient observation for 24 to 48 hours to monitor for recurrence. More recent but limited observations suggest that patients who have undergone successful ARE can safely be discharged after 4 to 6 hours of observation. Our primary objective was to identify risk factors associated with early recurrence. Our secondary objectives included validating risk criteria from prior studies and identifying risk factors for ARE failures. DESIGN/METHODS: A retrospective cohort study of children discharged from a large urban quaternary hospital with a final diagnosis of intussusception (International Classification of Diseases, Ninth Revision, code 560.0) or who underwent ARE from 2005 to 2015 was identified. Demographic data, radiology images, and clinical course were recorded. Repeat visits, cases with incomplete medical records, and those with incorrect diagnoses were excluded. RESULTS: A total of 250 cases were identified. Two hundred cases were included for analysis. Fifty were excluded. Of the 163 who had successful reduction with ARE, 22 patients (13.5%) recurred, and 12 (7.3%) recurred within 48 hours. Fever (odds ratio, 4.25; P = 0.04; 95% confidence interval, 1.04-17.3) and female sex (odds ratio, 7.94; P = 0.01; 95% confidence interval, 1.82-34.6) were independently associated with early recurrence. No radiologic features were associated with early recurrence. CONCLUSIONS: Early recurrence after successful ARE was low, although more frequent in girls and in those with fever over 100.4°F. We therefore advocate for prospective studies to validate these risk criteria to identify patients who are at low risk for early recurrence and may qualify for early discharge from the emergency department.

Radiation dose monitoring in pediatric fluoroscopy: comparison of fluoroscopy time and dose-area product thresholds for identifying high-exposure cases.

BACKGROUND: Fluoroscopy time has been used as a surrogate for radiation dose monitoring in pediatric fluoroscopy; however it does not account for factors such as magnification or collimation. Dose-area product (DAP) is a more accurate measure of radiation exposure but its dependence on patient weight and body-part thickness is a challenge in children of varying ages. OBJECTIVE: To determine whether fluoroscopy time and DAP produce concurrent results when they are used to identify high-exposure cases, and to establish radiation dose thresholds for our institution. MATERIALS AND METHODS: During a 2-year period we prospectively monitored pediatric fluoroscopy studies performed at the Children's Hospital at Montefiore. We recorded study type, fluoroscopy time, DAP, patient age, weight and height. We then calculated 90th percentile fluoroscopy time and DAP thresholds for weight and age. RESULTS: We evaluated 1,011 cases (453 upper gastrointestinal [UGI] series, 266 voiding cystourethrograms [VCUGs], 120 contrast enemas, 108 speech studies, and 64 esophagrams). Fluoroscopy time demonstrated moderate correlation with DAP (rs=0.45, P<0.001, Spearman rank). DAP strongly correlated with patient weight (rs=0.71, P<0.001) and age (rs=0.70, P<0.001). Concordance of cases exceeding 90th percentile thresholds for fluoroscopy time and DAP were κ=0.27 for UGI series and κ=0.49 for VCUG for weight-based cutoffs, and κ=0.36 for UGI series and κ=0.40 for VCUG for age-based cutoffs. CONCLUSION: The limited correlation of fluoroscopy time with DAP suggests these methods are not equivalent for dose monitoring. However, the strong correlation of DAP with patient weight and age presents a challenge for establishing DAP thresholds in children, who range widely in size. Despite controlling for weight or age, there was limited overlap of cases exceeding the 90th percentile threshold for fluoroscopy time and DAP. This further reinforces the non-overlapping outcome of these two methods and indicates that fluoroscopy time might be inadequate for dose monitoring.

Narrowing of ischiofemoral and quadratus femoris spaces in pediatric ischiofemoral impingement.

OBJECTIVE: To correlate MRI findings of quadratus femoris muscle edema (QFME) with narrowing of the ischiofemoral space (IFS) and quadratus femoris space (QFS) in children, and to identify threshold values reflecting an anatomic architecture that may predispose to ischiofemoral impingement. MATERIALS AND METHODS: A case-control retrospective MRI review of 49 hips in 27 children (mean, 13 years) with QFME was compared to 49 hips in 27 gender and age-matched controls. Two radiologists independently measured IFS and QFS. Generalized linear mixed-effects models were fit to compare IFS and QFS values between cases and controls, and adjust for correlation in repeated measures from the same subject. Receiver operating characteristic (ROC) analysis determined optimal threshold values. RESULTS: Compared to controls, cases had significantly smaller IFS (p < 0.001, both readers) and QFS (reader 1: p < 0.001; reader 2: p = 0.003). When stratified as preteen (< 13) or teenage (≥ 13), lower mean IFS and QFS were observed in cases versus controls in both age groups. Area under ROC curve for IFS and QFS was high in preteens (0.77 and 0.71) and teens (0.94 and 0.88). Threshold values were 14.9 mm (preteens) and 19 mm (teens) for IFS and 11.2 mm (preteens) and 11.1 mm (teens) for QFS. IFS and QFS were modestly correlated with age among controls only. CONCLUSIONS: Pediatric patients with QFME had significantly narrower QFS and IFS compared with controls. IFS and QFS were found to normally increase in size with age. Optimal cutoff threshold values were identified for QFS and IFS in preteens and teenagers.

Consensus Report by Pediatric Acute Lung Injury and Sepsis Investigators and Pediatric Blood and Marrow Transplantation Consortium Joint Working Committees: Supportive Care Guidelines for Management of Veno-Occlusive Disease in Children and Adolescents, Part 1: Focus on Investigations, Prophylaxis, and Specific Treatment.

Veno-occlusive disease (VOD) is a common and potentially fatal complication in children undergoing hematopoietic cell transplantation (HCT). It occurs in about one-third of all patients undergoing transplantation and is fatal in 50% of patients with severe disease. Early intervention and specific treatment with defibrotide are associated with improved outcomes. However, there is a lack of supportive care guidelines for management of the multiorgan dysfunction seen in most cases. There is high variability in the management of VOD, which may contribute to the increased morbidity and mortality. Although there is ample research in the specific treatment of VOD, there is paucity of literature regarding the management of ascites, transfusions requirements, fluids and electrolyte dysfunction, delirium, and investigations in children with VOD. The joint working committees of the Pediatric Acute Lung Injury and Sepsis Investigators and the Pediatric Blood and Marrow Transplantation Consortium collaborated to develop a series of evidence-based supportive care guidelines for management of VOD. The quality of evidence was rated and recommendations were made using Grading of Recommendations, Assessment, Development and Evaluation criteria. This manuscript is part 1 of the series and focuses on the need to develop these guidelines; methodology used to establish the guidelines; and investigations needed for diagnosis, prophylaxis, and treatment of VOD in children.

Hepatic Imaging in Neonates and Young Infants: State of the Art.

Neonatal liver disease is an important source of morbidity in the pediatric population. The manifestation of liver disease in young infants may be different than in older patients, and there are a number of diagnoses that are unique to this age group. Familiarity with these entities is important as imaging plays a key role in the diagnostic workup, and prompt diagnosis is necessary to prevent complications. This article reviews the spectrum of liver pathologies that can manifest in the first 6 months of life and is intended to educate the general radiologist who may be faced with interpretation of neonatal liver imaging. Categories of disease that will be reviewed include cholestatic diseases, tumors, vascular anomalies, and acquired diseases. The authors will also review optimization of ultrasonography (US) and magnetic resonance imaging of the liver and present a systematic method for interpretation of neonatal liver US findings in the context of clinical and laboratory findings. © RSNA, 2017.

Identifying intestinal malrotation on magnetic resonance examinations ordered for unrelated indications.

BACKGROUND: Anatomical imaging findings indicating normal bowel rotation can be identified on cross-sectional imaging, including magnetic resonance imaging (MRI) performed for non-related indications. OBJECTIVE: The goal of our study was to assess whether non-targeted MRI can accurately assess intestinal malrotation. MATERIALS AND METHODS: Four anatomical landmarks were assessed on MRIs of the chest, spine or abdomen performed from January 2006 to June 2014, on patients who also had upper gastrointestinal series (UGI) performed within 10 years of the MRI date: 1) retroperitoneal duodenum, 2) left upper quadrant duodenojejunal junction, 3) superior mesenteric artery to the left of the superior mesenteric vein, and 4) right lower quadrant cecum. Two attending radiologists, one pediatric and one abdominal radiologist, independently reviewed the MR images. The pediatric radiologist reviewed images from UGI (considered the gold standard) to determine the intestinal rotation for each case. Validation of the criteria was performed on new patients imaged through January 2016. RESULTS: The original cohort included 109 MRIs (15 chest, 41 spine and 53 abdomen) done on 109 patients (42% males, mean age: 10.2 years). If each of the 4 anatomical questions were answered "yes" (4-YES), specificity was 100% for each radiologist and malrotation was appropriately excluded. Using the 4-YES criteria, the pediatric radiologist excluded malrotation in 71 patients (65%) and the abdominal radiologist excluded it in 65 (60%), with concurrence for 57 patients. Validation of the 4-YES criteria in 23 new patients appropriately proved the 4-YES rule, with neither labeling the one new malrotation case 4-YES. CONCLUSION: If a radiologist can confidently answer "yes" to the four questions evaluated in this study, then intestinal rotation can be safely considered normal. Normal bowel rotation should be commented upon in MRI reports when these four anatomical locations are imaged, thus helping patients avoid unnecessary UGI and radiation exposure.

Non-central peripherally inserted central catheters in neonatal intensive care: complication rates and longevity of catheters relative to tip position.

BACKGROUND: Peripherally inserted central catheters (PICCs) represent a mainstay of intravascular access in the neonatal intensive care setting when long-term vascular access is needed. Ideally, PICCs should be inserted and maintained in a central position with the tip ending in the superior or inferior vena cava. This is not always achievable, and sometimes the tip remains in a peripheral location. Higher complication rates have been reported with non-central PICCs; however these findings have not been confirmed in a solely neonatal series and PICCs with tips in peripheral veins have not been studied. OBJECTIVE: To compare complication rates and length of catheter duration related to PICC position in neonates. MATERIALS AND METHODS: We conducted a retrospective analysis of all PICCs inserted in term and preterm infants in a tertiary neonatal intensive care unit between May 2007 and December 2009. A single pediatric radiologist reinterpreted the catheter tip site on initial anteroposterior (AP) chest radiographs and categorized sites as central (superior vena cava, inferior vena cava, brachiocephalic vein), intermediate (subclavian, axillary, common or external iliac veins), or peripheral (veins peripheral to axillary or external iliac veins). We analyzed complication rates and length of catheter duration among the three categories. RESULTS: We collected data on a total of 176 PICCs. Infants with PICCs in a central location had a significantly lower complication rate (18/97, 19%) than those with the PICC tip in an intermediate (24/64, 38%) or peripheral (9/15, 60%) locations (P=0.0003). Length of catheter duration was noted to be longest with central, intermediate with intermediate, and shortest with peripheral PICC tip locations (17.7±14.8 days for central vs. 11.4±10.7 days for intermediate vs. 5.4±2.5 days for peripheral, P=0.0003). CONCLUSION: A central location is ideal for the tip of a PICC. When this is not achievable, an intermediate location is preferable to a more peripheral position.

MRI usage in a pediatric emergency department: an analysis of usage and usage trends over 5 years.

BACKGROUND: Magnetic resonance imaging (MRI) usage has anecdotally increased due to the principles of ALARA and the desire to Image Gently. Aside from a single abstract in the emergency medicine literature, pediatric emergency department MRI usage has not been described. OBJECIVE: Our objective was to determine whether MRI use is indeed increasing at a high-volume urban pediatric emergency department with 24/7 MRI availability. Also, we sought to determine which exams, time periods and demographics influenced the trend. MATERIALS AND METHODS: Institutional Review Board exemption was obtained. Emergency department patient visit and exam data were obtained from the hospital database for the 2011-2015 time period. MRI usage data were normalized using emergency department patient visit data to determine usage rates. The z-test was used to compare MRI use by gender. The chi-square test was used to test for trends in MRI usage during the study period and in patient age. MRI usage for each hour and each weekday were tabulated to determine peak and trough usage times. RESULTS: MRI usage rate per emergency department patient visit was 0.36%. Headache, pain and rule-out appendicitis were the most common indications for neuroradiology, musculoskeletal and trunk exams, respectively. Usage in female patients was significantly greater than in males (0.42% vs. 0.29%, respectively, P<0.001). Usage significantly increased during the 5-year period (P<0.001). Use significantly increased from age 3 to 17 (0.011% to 1.1%, respectively, P<0.001). Sixty percent of exams were performed after-hours, the highest volume during the 10 p.m. hour and lowest between 4 a.m. and 9 a.m. MRI use was highest on Thursdays and lowest on Sundays (MRI on 0.45% and 0.22% of patients, respectively). CONCLUSION: MRI use in children increased during the study period, most notably in females, on weekdays and after-hours.

Three-dimensional ultrasound of the neonatal brain: technical approach and spectrum of disease.

Brain pathology is an important cause of morbidity and mortality in neonates, especially in the premature population. While conventional two-dimensional neurosonography is traditionally used for screening, diagnosis and monitoring of brain disorders such as germinal matrix hemorrhage, periventricular leukomalacia and hydrocephalus, three-dimensional ultrasonography has gained popularity in a variety of clinical applications in recent years. Three-dimensional ultrasonography is not yet widely utilized in pediatric imaging but is a potentially powerful tool for evaluating the neonatal brain. Three-dimensional neurosonography allows imaging of the entire brain in a single volumetric sweep and offers the capability of reconstructing images in the axial plane and performing volumetric analyses that are unavailable in conventional two-dimensional neurosonography. The purpose of this article is two-fold: (1) to present the technical aspects of three-dimensional neurosonography and (2) to illustrate the potential applications of three-dimensional neurosonography in the context of commonly encountered neonatal neuropathology.