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Pediatric bowel obstructions are one of the most common surgical emergencies in children, and imaging plays a vital role in the evaluation and diagnosis. An evidence-based and practical imaging approach to diagnosing and localizing pediatric bowel obstructions is essential for optimal pediatric patient care. This article discusses an up-to-date practical diagnostic imaging algorithm for pediatric bowel obstructions and presents the imaging spectrum of pediatric bowel obstructions and their underlying causes.

Pediatric abdominal masses are commonly encountered in the pediatric population, with a broad differential diagnosis that encompasses benign and malignant entities. The primary role of abdominal imaging in the setting of a suspected pediatric abdominal mass is to establish its presence, as nonneoplastic entities can mimic an abdominal mass, and to identify characteristic imaging features that narrow the differential diagnosis. In the setting of a neoplasm, various imaging modalities play an important role to characterize the mass, stage extent of disease, and assist in presurgical planning. The purpose of this article is to discuss a practical imaging algorithm for suspected pediatric abdominal masses and to describe typical radiological findings of the commonly encountered abdominal masses in neonates and children with emphasis on imaging guidelines and recommendations.

OBJECTIVE. The purpose of this article is to review new pediatric lung disorders-including disorders that have occurred in recent years years such as severe acute respiratory syndrome (SARS), swine-origin influenza A (H1N1), Middle East respiratory syndrome (MERS), e-cigarette or vaping product use-associated lung injury (EVALI), and coronavirus disease (COVID-19) pneumonia-to enhance understanding of the characteristic imaging findings. CONCLUSION. Although the clinical symptoms of SARS, H1N1, MERS, EVALI, and COVID-19 pneumonia in pediatric patients may be nonspecific, some characteristic imaging findings have emerged or are currently emerging. It is essential for radiologists to have a clear understanding of the characteristic imaging appearances of these lung disorders in pediatric patients to ensure optimal patient care.

Understanding of coronavirus disease 2019 is rapidly evolving with new articles on the subject daily. This flood of articles can be overwhelming for busy practicing clinicians looking for key pieces of information that can be applied in daily practice. This review article synthesizes the reported imaging findings in pediatric COVID‐19 across the literature, offers imaging differential diagnostic considerations and useful radiographic features to help differentiate these entities from COVID‐19, and provides recommendations for ordering imaging studies to evaluate suspected cases of pediatric COVID‐19. This article is protected by copyright. All rights reserved.

Hematopoietic stem cell transplantation is an intravenous transfusion of pluripotent stem cells to repopulate the marrow and restore immunocompetence. However, before transplantation, the patient undergoes a conditioning regimen to eradicate the underlying disease, subsequently resulting in an immunocompromised state. Serious and some life-threatening complications involving any organ can occur. Currently, with advances in hematopoietic stem cell transplantation techniques and posttransplant management, more pediatric patients are now living longer and into their adulthood. The goal of this review article is to discuss the common neurologic, pulmonary, and abdominal complications associated with hematopoietic stem cell transplantation with emphasis on their imaging characteristics.

End-stage organ failure is commonly treated with transplantation of the respective failing organ. Although outcomes have progressively improved over the decades, early and late complications do occur, and are often diagnosed by imaging. Given the increasing survival rates of transplant patients, the general radiologist may encounter these patients in the outpatient setting. Awareness of the normal radiologic findings after transplantation, and imaging findings of the more common complications, is therefore important. We review and illustrate the imaging assessment of complications from lung, liver, and renal transplantation, highlighting the key similarities and differences between pediatric and adult patients.

Pediatric abdominal masses are commonly encountered in the pediatric population, with a broad differential diagnosis that encompasses benign and malignant entities. The primary role of abdominal imaging in the setting of a suspected pediatric abdominal mass is to establish its presence, as nonneoplastic entities can mimic an abdominal mass, and to identify characteristic imaging features that narrow the differential diagnosis. In the setting of a neoplasm, various imaging modalities play an important role to characterize the mass, stage extent of disease, and assist in presurgical planning. The purpose of this article is to discuss a practical imaging algorithm for suspected pediatric abdominal masses and to describe typical radiological findings of the commonly encountered abdominal masses in neonates and children with emphasis on imaging guidelines and recommendations.

Pediatric bowel obstructions are one of the most common surgical emergencies in children, and imaging plays a vital role in the evaluation and diagnosis. An evidence-based and practical imaging approach to diagnosing and localizing pediatric bowel obstructions is essential for optimal pediatric patient care. This article discusses an up-to-date practical diagnostic imaging algorithm for pediatric bowel obstructions and presents the imaging spectrum of pediatric bowel obstructions and their underlying causes.

Pediatric renal tumors may be malignant or benign. Wilms tumor, the most common malignant pediatric renal tumor, arises sporadically or with various syndromes. Renal cell carcinoma typically presents in older children. Renal clear cell sarcoma and rhabdoid tumor are typically less common, more aggressive, and present in younger children. Benign renal tumors include mesoblastic nephroma, multilocular cystic renal tumor, angiomyolipoma, and metanephric adenoma. Lymphoma and leukemia may secondarily involve the kidney. Although there is overlap in the imaging appearance of several pediatric renal tumors, magnetic resonance characteristics and clinical data narrow the differential diagnosis and suggest a specific diagnosis. This article reviews current MR techniques, as well as the common MR imaging characteristics of malignant and benign pediatric renal neoplasms.

Computed tomography (CT) is the imaging modality of choice for evaluating mediastinal masses detected by radiography or clinical presentation. However, CT results can often be indeterminate. Thoracic magnetic resonance (MR) imaging is a noninvasive way to characterize mediastinal lesions, site of origin, and involvement of adjacent structures by providing higher soft tissue contrast than CT, with superior tissue characterization and higher diagnostic specificity. Thoracic MR imaging of mediastinal masses can increase diagnostic certainty, reduce the number of surgical interventions, and improve clinical decision making. In this review article, current imaging techniques and clinical applications of MR imaging as a problem-solving tool for assessing mediastinal masses in pediatric patients are discussed.

Administration of intravenous contrast media to children is a routine practice at many clinical imaging centers, that can involve special considerations. In this paper, we provide practical information to facilitate optimal performance and oversight of this task. We provide targeted screening questions that can help to identify high-risk pediatric patients for both iodine-based and gadolinium-based intravenous contrast media administration. These include children at risk for allergic-like reactions, thyroid dysfunction, contrast-induced nephropathy, and nephrogenic systemic fibrosis. We make recommendations for addressing "yes" responses to screening questions using risk stratification schema that are specific to children. We also present criteria for selecting children for premedication prior to intravenous contrast administration, and suggest pediatric regimens. Additionally, we discuss practical nuances of intravenous contrast media administration to children and provide a quick-reference table of appropriate treatments with pediatric dosages for adverse contrast reactions.

OBJECTIVE. Intussusception is the most common cause of intestinal obstruction in young children. Radiology has a key role in its diagnosis and treatment. This systematic review summarizes the currently available evidence for best practices in radiologic management of pediatric intussusception. CONCLUSION. High diagnostic accuracy and lack of ionizing radiation make ultrasound (US) the preferred imaging modality for diagnosing intussusception. For intussusception reduction, fluoroscopy-guided pneumatic enema and US-guided hydrostatic enema are equally dependable and safe techniques. The areas that warrant further research in this field include the efficacy and safety of the US-guided pneumatic enema, potential benefits of sedation and general anesthesia for the reduction procedure, and the optimal management of intussusceptions potentially involving pathologic lead points.

Cochlear implant depth of insertion affects audiologic outcomes and can be measured in adults using plain films obtained in the "cochlear view." The objective of this study was to assess interrater and intrarater reliability of measuring depth of insertion using cochlear view radiography.Prospective, observational.Tertiary referral pediatric hospital.Patients aged 11 months to 20 years (median, 4 years; interquartile range [IQR], 1-8 years) undergoing cochlear implantation at our institution were studied over 1 year. Children underwent cochlear view imaging on postoperative day 1. Films were deidentified and 1 image per ear was selected. Two cochlear implant surgeons and 2 radiologists evaluated each image and determined angular depth of insertion. Images were re-reviewed 6 weeks later by all raters. Inter- and intrarater reliability were calculated with intraclass correlation coefficients (ICCs).Fifty-seven ears were imaged from 42 children. Forty-nine ears (86%) had successful cochlear view x-rays. Median angular depth of insertion was 381° (minimum, 272°; maximum, 450°; IQR, 360°-395°) during the first round of measurement. Measurements of the same images reviewed 6 weeks later showed median depth of insertion of 382° (minimum, 272°; maximum, 449°; IQR, 360°-397°). Interrater and intrarater reliability ICCs ranged between 0.81 and 0.96, indicating excellent reliability.Postoperative cochlear view radiography is a reliable tool for measurement of cochlear implant depth of insertion in infants and children. Further studies are needed to determine reliability of intraoperatively obtained cochlear view radiographs in this population.

Coronavirus disease 2019 (COVID-19) has quickly spread since it was first detected in December 2019 and has evolved into a global pandemic with over 1.7 million confirmed cases in over 200 countries around the world at the time this document is being prepared. Owing to the novel nature of the virus and the rapidly evolving understanding of the disease, there is a great deal of uncertainty surrounding the diagnosis and management of COVID-19 pneumonia in pediatric patients. Chest imaging plays an important role in the evaluation of pediatric patients with COVID-19; however, there is currently little information available describing imaging manifestations of COVID-19 in pediatric patients and even less information discussing the utilization of imaging studies in pediatric patients. To specifically address these concerns, a group of international experts in pediatric thoracic imaging from five continents convened to create a consensus statement describing the imaging manifestations of COVID-19 in the pediatric population, discussing the potential utility of structured reporting during the COVID-19 pandemic, and generating consensus recommendations for utilization of chest radiographs and CT in the evaluation of pediatric patients with COVID-19. The results were compiled into two structured reporting algorithms (one for chest radiographs and one for chest CT) and eight consensus recommendations for the utilization of chest imaging in pediatric COVID-19 infection. © RSNA, 2020.

OBJECTIVE. Dual-energy CT is gaining increasing recognition as a valuable diagnostic tool for assessing abdominal neoplasms. Nevertheless, much of the literature has focused on its use in adults. This review article illustrates specific tools available with dual-energy CT in the evaluation of pediatric abdominal neoplasms. Additionally, common imaging artifacts and pitfalls in dual-energy CT of the pediatric abdomen are outlined. CONCLUSION. Dual-energy CT can augment diagnostic yield in the imaging evaluation of pediatric abdominal neoplasms.

Neonatal bowel disorders represent a diverse set of congenital and acquired conditions spanning the alimentary tract. Clinical presentation is variable and reflects both the site of gastrointestinal involvement as well as the underlying pathology. Several of the neonatal bowel disorders represent true surgical emergencies and require prompt diagnosis for optimal outcomes. Radiologic studies, which may consist of radiography, upper gastrointestinal series, barium enema, and/or ultrasonography, provide essential data to achieve the correct diagnosis.

A spectrum of vascular complications can be seen in pediatric liver transplant patients, including occlusion and hemodynamically significant narrowing of the vessels that provide inflow to or outflow from the graft. Intraoperative Doppler ultrasound (US) has the potential benefit of identifying vascular complications in pediatric liver transplant patients prior to abdominal closure. Importantly, intraoperative Doppler US can be used as a problem-solving tool in situations such as position-dependent kinking of the portal or hepatic veins, or in suspected vasospasm of the hepatic artery. Furthermore, this technique can be used for real-time reassessment after surgical correction of vascular complications. This pictorial review of intraoperative Doppler US in pediatric liver transplant patients illustrates normal findings and common vascular complications, including examples after surgical correction, in the perioperative period.

Neonatal gastrointestinal emergencies are caused by a diverse set of primarily congenital entities that may affect the upper or lower gastrointestinal tracts, and occasionally both. Although a diagnosis can sometimes be made on prenatal imaging, more commonly patients present after birth and require prompt diagnosis to facilitate timely treatment. Imaging plays a central role in the accurate diagnosis of these entities and typically consists of an initial abdominal series followed by either an upper gastrointestinal series or contrast enema. The authors review the most common neonatal gastrointestinal emergencies and provide a step-by-step approach to the accurate imaging diagnosis.

The imaging evaluation of the neonate in respiratory distress has been described since the most early days of pediatric radiology but advances in diagnosis and treatment have changed the patient population presenting with these conditions and altered the imaging findings. In this article, the range of conditions that cause neonatal respiratory distress is depicted, including congenital lung malformations and lung disease in both preterm and full-term infants. An updated approach to the imaging of these conditions is reviewed, with a focus on changes that have resulted from advances in treatment and diagnosis.

Immunodeficiency syndromes can either be congenital due to a variety of inherited defects or secondary due to an underlying illness or iatrogenic immunosuppression related to chemotherapy, solid organ, or bone marrow transplantation. Irrespective of the cause, immunosuppressed patients have an increased susceptibility to developing infections, which are a significant cause of morbidity and mortality. In this article, we focus on abdominal infections in children who have iatrogenic immunosuppression related to chemotherapy, bone marrow, or solid organ transplant. The development of infection in this population of patients can be related to compromised mechanical barriers, neutrophil dysfunction, impaired cell-mediated as well as humoral immunities, and splenic dysfunction. The absolute granulocyte count is the most important determinant of susceptibility to bacterial and fungal pathogens in these children, whose risk of infection increases as a function of both degree and duration of neutropenia. Infections in the pediatric cancer patient, hematopoietic stem cell, or solid organ transplant recipient can be classified by classic time increments. Bacteria are isolated in the majority of cases of early neutropenia, whereas fungal pathogens typically cause infection in those with severe or prolonged neutropenic states. This dedicated article not only depicts the imaging findings of entities such as neutropenic colitis, infectious enterocolitis, and fungal infections that occur in children with iatrogenic immunosuppression from antineoplastic therapy as well as bone marrow and solid organ transplantation but discusses the pathophysiology leading to their development. Physician awareness of the types of infectious complications in this population, the time frame in which they classically occur, and the use of appropriate criteria to direct imaging can lead to earlier detection thereby affording patients the opportunity for prompt intervention and subsequently improved quality of life.

Pediatric renal tumors may be malignant or benign. Wilms tumor, the most common malignant pediatric renal tumor, arises sporadically or with various syndromes. Renal cell carcinoma typically presents in older children. Renal clear cell sarcoma and rhabdoid tumor are typically less common, more aggressive, and present in younger children. Benign renal tumors include mesoblastic nephroma, multilocular cystic renal tumor, angiomyolipoma, and metanephric adenoma. Lymphoma and leukemia may secondarily involve the kidney. Although there is overlap in the imaging appearance of several pediatric renal tumors, magnetic resonance characteristics and clinical data narrow the differential diagnosis and suggest a specific diagnosis. This article reviews current MR techniques, as well as the common MR imaging characteristics of malignant and benign pediatric renal neoplasms.

Computed tomography (CT) is the imaging modality of choice for evaluating mediastinal masses detected by radiography or clinical presentation. However, CT results can often be indeterminate. Thoracic magnetic resonance (MR) imaging is a noninvasive way to characterize mediastinal lesions, site of origin, and involvement of adjacent structures by providing higher soft tissue contrast than CT, with superior tissue characterization and higher diagnostic specificity. Thoracic MR imaging of mediastinal masses can increase diagnostic certainty, reduce the number of surgical interventions, and improve clinical decision making. In this review article, current imaging techniques and clinical applications of MR imaging as a problem-solving tool for assessing mediastinal masses in pediatric patients are discussed.

In the past decade, with improved surgical technique and knowledge of immunosuppression, pediatric lung and heart transplantation have been established as viable therapeutic interventions for pediatric patients with end-stage cardiopulmonary disease from various underlying congenital and acquired disorders. Although outcomes for pediatric patients are similar to those for adult patients, thoracic organ transplantation in this special age group carries unique challenges for preoperative and postoperative imaging evaluation. The article provides an up-to-date review of the postoperative transplant anatomy, imaging techniques, and complications of pediatric lung and heart transplantation.

Administration of intravenous contrast media to children is a routine practice at many clinical imaging centers, that can involve special considerations. In this paper, we provide practical information to facilitate optimal performance and oversight of this task. We provide targeted screening questions that can help to identify high-risk pediatric patients for both iodine-based and gadolinium-based intravenous contrast media administration. These include children at risk for allergic-like reactions, thyroid dysfunction, contrast-induced nephropathy, and nephrogenic systemic fibrosis. We make recommendations for addressing "yes" responses to screening questions using risk stratification schema that are specific to children. We also present criteria for selecting children for premedication prior to intravenous contrast administration, and suggest pediatric regimens. Additionally, we discuss practical nuances of intravenous contrast media administration to children and provide a quick-reference table of appropriate treatments with pediatric dosages for adverse contrast reactions.

Neonatal bowel disorders require prompt and accurate diagnosis to avoid potential morbidity and mortality. Symptoms such as feeding intolerance, emesis, or failure to pass meconium may prompt a radiologic evaluation.We discuss the most common neonatal bowel disorders and present a practical imaging algorithm for trainees and general radiologists.

Objectives/Hypothesis To examine the relationship between bony cochlear nerve canal (BCNC) width, degree of hearing loss, and speech discrimination in children with unilateral sensorineural hearing loss (USNHL). Study Design Retrospective chart review (case-control study). Methods Audiometric database was cross-referenced with radiologic database at pediatric tertiary care facility to identify children with USNHL and temporal bone computed tomography. BCNC widths were measured independently by two radiologists blinded to affected ear. Regression analyses investigated associations among variables. Results One hundred and sixty children with USNHL had temporal bone imaging. Mean BCNC width was significantly smaller in affected ears, P = 0.0001. Narrower width was associated with more severe hearing loss, P = 0.01. Among children who had narrower cochlear nerve canals in affected ears compared to unaffected ears, smaller width was associated with lower speech discrimination score, P = 0.03. Increasing asymmetry in BCNC width between affected and unaffected ears was associated with poorer discrimination scores, P = 0.02. Among ears with asymmetrically smaller cochlear nerve canals, a 1-mm reduction in cochlear canal width between the normal and affected ear was associated with 30.4% lower word recognition score percentage in the affected ear, P =

Trichobezoars are an uncommon cause of acute abdominal pain. We present a case of a 12-year-old girl with a history of a trichobezoar who presented to the emergency department with acute abdominal pain. Abdominal sonography was performed which suggested portal venous gas and showed complex peritoneal fluid. Subsequent computed tomography demonstrated both gastric and small bowel bezoars, with a jejunojejunal intussusception, and confirmed portal venous gas and complex ascites. At the time of surgery, there was evidence of intestinal and biliary perforation. Our case illustrates a constellation of complications in association with a long-standing trichobezoar.

Objective To report and compare medical, radiological, and audiological outcomes in pediatric cochlear implant recipients who underwent 1.5 and 3 Tesla strength MRI with and without retained magnet. Methods Retrospective chart review at a tertiary care pediatric hospital and review of literature. Patients were identified via electronic medical records database search and were included if they had MRI after cochlear implant. Results Of twelve instances of MRI in pediatric cochlear implant recipients at our institution, two minor complications and one major complication were recorded. The rate of complication was equal between patients who underwent MRI with and without retained magnet. All minor complications resulted from MRI with retained magnet whereas the only major complication resulted from magnet removal. Two novel complications are reported, including: magnet removal resulting in silastic tear necessitating reimplantation and magnet dislocation with spontaneous reduction. Magnet removal significantly decreased the size of artifact, but did not alter the diagnostic utility of the MRI. While audiological measures varied chronologically from MRI scans, they did not appear to be appreciably altered by MRI. Conclusion MRI with and without magnet retention appear to carry risks of both major and minor complications. For the regions of interest for each scan, MRI quality was not appreciably altered by magnet status. Audiological measures appear unaffected by magnet status during MRI however, this may reflect natural variation.

To investigate the risk of hearing loss progression in each ear among children with unilateral hearing loss associated with ipsilateral bony cochlear nerve canal (BCNC) stenosis.Tertiary pediatric referral center.Children diagnosed with unilateral hearing loss who had undergone temporal bone computed tomography imaging and had at least 6 months of follow-up audiometric testing were identified from a prospective audiological database.Two pediatric radiologists blinded to affected ear evaluated imaging for temporal bone anomalies and measured bony cochlear canal width independently. All available audiograms were reviewed, and air conduction thresholds were documented.Progression of hearing loss was defined by a 10 dB increase in air conduction pure-tone average.One hundred twenty eight children met inclusion criteria. Of these, 54 (42%) had a temporal bone anomaly, and 22 (17%) had ipsilateral BCNC stenosis. At 12 months, rates of progression in the ipsilateral ear were as follows: 12% among those without a temporal bone anomaly, 13% among those with a temporal bone anomaly, and 17% among those with BCNC stenosis. Children with BCNC stenosis had a significantly greater risk of progression in their ipsilateral ear compared with children with no stenosis: hazard ratio (HR) 2.17, 95% confidence interval (CI) (1.01, 4.66), p value 0.046. When we compared children with BCNC stenosis to those with normal temporal bone imaging, we found that the children with stenosis had nearly two times greater risk estimate for progression, but this difference did not reach significance, HR 1.9, CI (0.8, 4.3), p = 0.1. No children with BCNC stenosis developed hearing loss in their contralateral year by 12 months of follow-up.Children with bony cochlear nerve canal stenosis may be at increased risk for progression in their ipsilateral ear. Audiometric and medical follow-up for these children should be considered.

Neonatal gastrointestinal emergencies are caused by a diverse set of primarily congenital entities that may affect the upper or lower gastrointestinal tracts, and occasionally both. Although a diagnosis can sometimes be made on prenatal imaging, more commonly patients present after birth and require prompt diagnosis to facilitate timely treatment. Imaging plays a central role in the accurate diagnosis of these entities and typically consists of an initial abdominal series followed by either an upper gastrointestinal series or contrast enema. The authors review the most common neonatal gastrointestinal emergencies and provide a step-by-step approach to the accurate imaging diagnosis.

Vertical expandable prosthetic titanium rib (VEPTR) is increasingly used in the treatment of thoracic insufficiency, idiopathic and neuromuscular scoliosis and chest wall defects in children. In contrast to spinal fusion surgery, the VEPTR allows for growth while stabilizing the deformity. We illustrate the common indications and normal radiographic appearance of the three common configurations of VEPTR (cradle-to-cradle assembly, cradle with lumbar extension assembly, cradle-to-ala hook assembly). There is a relatively high rate of reported complications with VEPTR in the literature. We discuss the potential complications of VEPTR, including infection, rib fracture, dislodged hardware and neurological injury, with an emphasis on imaging diagnosis.

An interactive Web-based learning module on the temporal bone has been developed. It shows normal temporal bone anatomy in four imaging planes: axial, coronal, and parallel and perpendicular to the long axis of the petrous bone. After reviewing the normal anatomy, users should be able to identify key imaging features of pathologic conditions of the temporal bone. Children with congenital abnormalities of the temporal bone may present with conductive or sensorineural hearing loss or both and may have a genetic syndrome. Acute otitis media is the most common infection of the temporal bone and is most prevalent among children. Although imaging is unnecessary in uncomplicated otitis media, it is important for evaluation of infectious complications. Classically, temporal bone fractures were described as longitudinal or transverse with respect to the long axis of the petrous bone. However, it is increasingly recognized that many fractures have both longitudinal and transverse components. Patients with temporal bone fractures may have conductive or sensorineural hearing loss in addition to other complications. The most common tumor of the temporal bone at the cerebellopontine angle is the vestibular schwannoma. Paraganglioma is the second most common tumor of the temporal bone and the most common tumor of the middle ear. Supplemental material available at http://uwmsk.org/temporalbone/atlas.html.

Skeletal dysplasias are a large diverse group of disorders characterized by abnormal bone and cartilage growth. Approximately one-quarter of them are considered lethal in the perinatal period. This paper will review the components of the skeletal survey, the primary imaging tool for diagnosing dysplasias postnatally, emphasizing the use of an organized approach and appropriate descriptive terminology. Several illustrative cases of lethal and nonlethal dysplasias will be shown, with additional discussion of commonly associated genetic mutations and classification systems.

OBJECTIVE. This article reviews, through clinical case presentation and correlative imaging, a variety of conditions that cause right lower quadrant (RLQ) pain in children.CONCLUSION. This case-based review allows the reader to improve his or her understanding of the differential diagnosis and radiographic appearances of the entities that cause RLQ pain in children.

We devise models and algorithms to estimate the impact of current and future patient demand for examinations on Magnetic Resonance Imaging (MRI) machines at a hospital radiology department. Our work helps improve scheduling decisions and supports MRI machine personnel and equipment planning decisions. Of particular novelty is our use of scheduling algorithms to compute the competing objectives of maximizing examination throughput and patient-magnet utilization. Using our algorithms retrospectively can help (1) assess prior scheduling decisions, (2) identify potential areas of efficiency improvement and (3) identify difficult examination types. Using a year of patient data and several years of MRI utilization data, we construct a simulation model to forecast MRI machine demand under a variety of scenarios. Under our predicted demand model, the throughput calculated by our algorithms acts as an estimate of the overtime MRI time required, and thus, can be used to help predict the impact of different trends in examination demand and to support MRI machine staffing and equipment planning.

We present a web-based pediatric CT dose tool that estimates effective dose based on dose length product, patient age and region of body scanned. The tool also provides an estimate of additional lifetime risk of cancer from CT exams. These estimations are based on the interpolation of factors from published methods. The calculator serves as an educational tool that can be used by radiologists and clinicians to better understand CT dose and its associated risks.

The anatomy, normal postoperative radiological appearance, and imaging features of common postoperative complications of pediatric abdominal transplants are reviewed, including renal, liver, and intestinal transplants. Doppler ultrasound is the mainstay of imaging after transplantation. Computed tomography (CT) and CT angiography, MR imaging and magnetic resonance (MR) angiography, MR cholangiopancreatography, conventional angiography, and nuclear medicine imaging may be used for problem-solving in pediatric transplant patients. Accurate and timely radiological diagnosis of transplant complications facilitates appropriate treatment and minimizes morbidity and mortality.

OBJECTIVES The authors created a computer-based, interactive atlas of pediatric chest radiographs to facilitate (1) understanding of normal variants and (2) interpretation of pediatric chest radiographs in the acute setting. METHODS Seventy-three normal pediatric chest radiographs were selected for inclusion in the atlas by consensus after review by 3 pediatric radiologists. Sixteen abnormal pediatric chest radiographs showing a variety of abnormalities (infection, malignancy, congenital abnormalities, foreign body, and acquired disease), as well as 4 normal adult chest radiographs, were also included in the atlas. Images for the atlas were derived from Digital Imaging and Communications in Medicine-compliant data. The atlas software was written in C# and offers features of a picture archiving and communication system viewer. In addition, the atlas offers annotated series that describe particular radiographic features of normal variants and disease. RESULTS The digital, interactive pediatric chest atlas displays normal chest radiographs of children aged 7 days to 17.8 years, as well as 4 normal adult chest radiographs and 16 abnormal pediatric chest radiographs. The digital interactive format of the atlas allows for (1) easy manipulation of atlas cases and (2) direct comparison between normal atlas cases and provided abnormal cases, as well as (3) the potential for direct comparison with images displayed on an institution's picture archiving and communication system. The atlas is available for free download at http://www.seattlechildrens.org/radiologyeducation/pediatric-chest. CONCLUSIONS Improved interpretation of pediatric chest radiographs in the acute setting may be facilitated by a comprehensive, computer-based, pediatric chest atlas.

Determining the optimal CT technique to minimize patient radiation exposure while maintaining diagnostic utility requires patient-specific protocols that are based on patient characteristics. This work develops relationships between different anthropometrics and CT image noise to determine appropriate protocol classification schemes.We measured the image noise in 387 CT examinations of pediatric patients (222 boys, 165 girls) of the chest, abdomen, and pelvis and generated mathematic relationships between image noise and patient lateral and anteroposterior dimensions, age, and weight.At the chest level, lateral distance (ld) across the body is strongly correlated with weight (ld = 0.23 × weight + 16.77; R(2) = 0.93) and is less well correlated with age (ld = 1.10 × age + 17.13; R(2) = 0.84). Similar trends were found for anteroposterior dimensions and at the abdomen level. Across all studies, when acquisition-specific parameters are factored out of the noise, the log of image noise was highly correlated with lateral distance (R(2) = 0.72) and weight (R(2) = 0.72) and was less correlated with age (R(2) = 0.62). Following first-order relationships of image noise and scanner technique, plots were formed to show techniques that could achieve matched noise across the pediatric population.Patient lateral distance and weight are essentially equally effective metrics to base maximum technique settings for pediatric patient-specific protocols. These metrics can also be used to help categorize appropriate reference levels for CT technique and size-specific dose estimates across the pediatric population.

We present a 16-year-old boy with autoimmune liver disease and longstanding portal hypertension in whom a CT arteriogram demonstrated a large aneurysm arising from the distal, extra-parenchymal portion of the splenic artery. Because of its location adjacent to multiple venous collaterals, the aneurysm was indistinguishable from splenic varices on initial imaging with Doppler sonography and on portal venous-phase CT. There is an increased risk of rupture of splenic artery aneurysms in the post-liver transplant period, with high associated mortality, and therefore diagnosis of splenic artery aneurysm prior to liver transplantation is clinically important. It is quite possible that the diagnosis of splenic artery aneurysm in this case would have been missed in the absence of dedicated arterial-phase imaging. As radiologists strive to reduce radiation exposure in children, this case highlights a potential diagnostic pitfall of both Doppler sonography and venous or single-acquisition arterial/venous-phase CT angiogram in children with venous collaterals and an undiagnosed splenic artery aneurysm.

A 4-year-old boy presented with moderate to profound mixed hearing loss in the right ear and moderate to severe mixed hearing loss in the left ear, prompting a temporal bone CT scan. Images revealed partial dehiscence of the right posterior semicircular canal. Semicircular canal dehiscence and its associated clinical syndrome have been described in adults. We present this case as a unique finding in a child and discuss the possible clinical and research implications.

Follicular and Hürthle cell carcinomas of the thyroid cannot be differentiated from adenomas by either preoperative fine needle aspiration or intraoperative frozen section examination, and yet there exist potentially significant differences in the recommended surgical management. We examined, by PCR-based microsatellite polymorphism analysis, DNA obtained from 83 thyroid neoplasms [22 follicular adenomas, 29 follicular carcinomas, 20 Hürthle cell adenomas (HA), and 12 Hürthle cell carcinomas (HC)] to determine whether a pattern of allelic alteration exists that could help distinguish benign from malignant lesions. Alterations were found in only 7.5% of informative PCR reactions from follicular neoplasms, whereas they were found in 23.3% of reactions from Hürthle cell neoplasms. Although there were no significant differences between follicular adenoma and follicular carcinoma, HC demonstrated a significantly greater percentage of allelic alteration than HA on chromosomal arms 1q (P < 0.001) and 2p (P < 0.05) by Fisher’s exact test. The documentation of an alteration on either 1q or 2p was 100% sensitive and 65% specific in the detection of HC (P < 0.0005, by McNemar’s test).In conclusion, PCR-based microsatellite polymorphism analysis may be a useful technique in distinguishing HC from HA. Potentially, the application of this technique to aspirated material may allow this distinction preoperatively and thus facilitate more optimal surgical management. Consistent regions of allelic alteration may also indicate the locations of critical genes, such as tumor suppressor genes or oncogenes, that are important in the progression from adenoma to carcinoma. Finally, this study demonstrates that Hürthle cell neoplasms, now considered variants of follicular neoplasms, differ significantly from follicular neoplasms on a molecular level.