Can magnetic resonance imaging replace computed tomography scans in the evaluation of pediatric post-appendectomy abscess?

BACKGROUND: Computed tomography scans have been used when cross-axial imaging is required to evaluate pediatric post-appendectomy abscesses. To reduce a source of radiation exposure, our institution converted to using contrast-enhanced magnetic resonance imaging to replace computed tomography scans in this clinical context. Our aim is to evaluate the performance of magnetic resonance imaging compared to computed tomography scans and associated clinical outcomes in this patient population. METHODS: A contrast-enhanced comprehensive magnetic resonance imaging protocol was implemented to evaluate a post-appendectomy abscess in 2018. A retrospective chart review was performed from 2015 to 2022 for pediatric patients (<18 years old) with prior appendectomy and subsequent cross-sectional imaging to evaluate for an intraabdominal abscess. Patient characteristics and clinical parameters between the 2 modalities were abstracted and compared using standard univariate statistics. RESULTS: There were a total of 72 post-appendectomy patients who received cross-axial imaging, which included 43 computed tomography scans and 29 magnetic resonance imaging during the study interval. Patient demographics were comparable between cohorts and rates of perforated appendicitis at the index operation (computed tomography: 79.1% vs magnetic resonance imaging: 86.2%). Missed abscess rate, abscess size, management technique, drainage culture results, readmission, and reoperation were similar between imaging modalities. Median request to scan time was longer for magnetic resonance imaging than computed tomography (191.5 vs 108 minutes, P = .04). The median duration of a comprehensive magnetic resonance imaging scan was 32 minutes (interquartile range 28-50.5 minutes). CONCLUSION: Contrast-enhanced magnetic resonance imaging provides an alternative cross-sectional imaging modality to computed tomography scans to evaluate pediatric post-appendectomy abscesses.

Imaging of Right Lower Quadrant Pain in Children and Adolescents: AJR Expert Panel Narrative Review.

Right lower quadrant (RLQ) pain is a common clinical presentation in children, and accurate clinical diagnosis remains challenging given that this nonspecific presentation is associated with numerous surgical and nonsurgical conditions. The broad differential diagnosis varies by patient age and sex. Important considerations in the selection of a diagnostic imaging strategy include the sequencing, performance, and cost of tests. This article provides a comprehensive narrative review of the diagnostic imaging of RLQ pain in children and adolescents, including a discussion of the complementary roles of ultrasound, CT, and MRI; description of key imaging findings based on available evidence; and presentation of salient differential diagnoses. Subspecialized pediatric emergency medicine and surgical perspectives are also provided as further clinical insight into this common, but often challenging, scenario. Finally, the current status of imaging of RLQ pain in children and adolescents is summarized on the basis of expert consensus.

ACR Appropriateness Criteria® Osteomyelitis or Septic Arthritis-Child (Excluding Axial Skeleton).

Imaging plays an integral role in the evaluation of suspected musculoskeletal infections in children, not only in the accurate identification of infection such as osteomyelitis or septic arthritis, but also in guiding management. Various diagnostic modalities serve different purposes in the assessment of suspected pediatric musculoskeletal infections. The purpose of this document is to provide imaging guidance in the most frequently encountered clinical scenarios in which osteomyelitis and/or septic arthritis are suspected, outside of the axial skeleton. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion.

ACR Appropriateness Criteria® Crohn Disease-Child.

Crohn disease is an inflammatory condition of the gastrointestinal tract with episodes of exacerbation and remission occurring in children, adolescents, and adults. Crohn disease diagnosis and treatment depend upon a combination of clinical, laboratory, endoscopic, histological, and imaging findings. Appropriate use of imaging provides critical information in the settings of diagnosis, assessment of acute symptoms, disease surveillance, and therapy monitoring. Four variants are discussed. The first variant discusses the initial imaging for suspected Crohn disease before established diagnosis. The second variant pertains to appropriateness of imaging modalities during suspected acute exacerbation. The third variant is a substantial discussion of recommendations related to disease surveillance and monitoring of Crohn disease. Finally, panel recommendations and discussion of perianal fistulizing disease imaging completes the document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The current and future roles of artificial intelligence in pediatric radiology.

Artificial intelligence (AI) is a broad and complicated concept that has begun to affect many areas of medicine, perhaps none so much as radiology. While pediatric radiology has been less affected than other radiology subspecialties, there are some well-developed and some nascent applications within the field. This review focuses on the use of AI within pediatric radiology for image interpretation, with descriptive summaries of the literature to date. We highlight common features that enable successful application of the technology, along with some of the limitations that can inhibit the development of this field. We present some ideas for further research in this area and challenges that must be overcome, with an understanding that technology often advances in unpredictable ways.

Artificial intelligence development in pediatric body magnetic resonance imaging: best ideas to adapt from adults.

Emerging manifestations of artificial intelligence (AI) have featured prominently in virtually all industries and facets of our lives. Within the radiology literature, AI has shown great promise in improving and augmenting radiologist workflow. In pediatric imaging, while greatest AI inroads have been made in musculoskeletal radiographs, there are certainly opportunities within thoracoabdominal MRI for AI to add significant value. In this paper, we briefly review non-interpretive and interpretive data science, with emphasis on potential avenues for advancement in pediatric body MRI based on similar work in adults. The discussion focuses on MRI image optimization, abdominal organ segmentation, and osseous lesion detection encountered during body MRI in children.

Safety issues related to intravenous contrast agent use in magnetic resonance imaging.

Gadolinium-based contrast agents (GBCAs) have been used to improve image quality of MRI examinations for decades and have an excellent overall safety record. However, there are well-documented risks associated with GBCAs and our understanding and management of these risks continue to evolve. The purpose of this review is to discuss the safety of GBCAs used in MRI in adult and pediatric populations. We focus particular attention on acute adverse reactions, nephrogenic systemic fibrosis and gadolinium deposition. We also discuss the non-GBCA MRI contrast agent ferumoxytol, which is increasing in use and has its own risk profile. Finally, we identify special populations at higher risk of harm from GBCA administration.

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.

ACR Appropriateness Criteria® Antenatal Hydronephrosis-Infant.

Antenatal hydronephrosis is the most frequent urinary tract anomaly detected on prenatal ultrasonography. It occurs approximately twice as often in males as in females. Most antenatal hydronephrosis is transient with little long-term significance, and few children with antenatal hydronephrosis will have significant obstruction, develop symptoms or complications, and require surgery. Some children will be diagnosed with more serious conditions, such as posterior urethral valves. Early detection of obstructive uropathy is necessary to mitigate the potential morbidity from loss of renal function. Imaging is an integral part of screening, diagnosis, and monitoring of children with antenatal hydronephrosis. Optimal timing and appropriate use of imaging can reduce the incidence of late diagnoses and prevent renal scarring and other complications. In general, follow-up neonatal ultrasound is recommended for all cases of antenatal hydronephrosis, while further imaging, including voiding cystourethrography and nuclear scintigraphy, is recommended for moderate or severe cases, or when renal parenchymal or bladder wall abnormalities are suspected. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Vomiting in Infants.

Vomiting in infants under the age of 3 months is one of the most common reasons for parents to seek care from their doctor or present to an emergency room. The imaging workup that ensues is dependent on several factors: age at onset, days versus weeks after birth, quality of emesis, bilious or nonbilious vomiting, and the initial findings on plain radiograph, suspected proximal versus distal bowel obstruction. The purpose of these guidelines is to inform the clinician, based on current evidence, what is the next highest yield and most appropriate imaging study to pursue a diagnosis. The goal is rapid and accurate arrival at a plan for treatment, whether surgical or nonsurgical. The following modalities are discussed for each variant of the symptom: plain radiography, fluoroscopic upper gastrointestinal series, fluoroscopic contrast enema, ultrasound of the abdomen, nuclear medicine gastroesophageal reflux scan. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Pneumonia in the Immunocompetent Child.

Pneumonia is one of the most common acute infections and the single greatest infectious cause of death in children worldwide. In uncomplicated, community-acquired pneumonia in immunocompetent patients, the diagnosis is clinical and imaging has no role. The first role of imaging is to identify complications associated with pneumonia such as pleural effusion, pulmonary abscess, and bronchopleural fistula. Radiographs are recommended for screening for these complications and ultrasound and CT are recommended for confirmation. The second role of imaging is to identify underlying anatomic conditions that may predispose patients to recurrent pneumonia. CT with intravenously administered contrast is recommended for this evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Developmental Dysplasia of the Hip-Child.

Developmental dysplasia of the hip (DDH) is the most common hip pathology in infants. Although its exact pathophysiology remains incompletely understood, its long-term prognosis depends not only on the severity of the dysphasia, but also on the timely implementation of appropriate treatment. Unrecognized and untreated hip subluxations and dislocations inevitably lead to early joint degeneration while overtreatment can produce iatrogenic complications, including avascular necrosis of the femoral head. In the past two decades, imaging has become an integral part of the clinical screening, diagnosis, and monitoring of children with DDH. Optimal timing for imaging and appropriate use of imaging can reduce the incidence of late diagnoses and prevent iatrogenic complications. In general, ultrasound of the hips is recommended in infants under the age of 4 months while pelvic radiography is recommended in older infants due to the fact that the femoral head ossific nucleus typically is not formed until 4 to 6 months of age. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Machine learning concepts, concerns and opportunities for a pediatric radiologist.

Machine learning, a subfield of artificial intelligence, is a rapidly evolving technology that offers great potential for expanding the quality and value of pediatric radiology. We describe specific types of learning, including supervised, unsupervised and semisupervised. Subsequently, we illustrate two core concepts for the reader: data partitioning and under/overfitting. We also provide an expanded discussion of the challenges of implementing machine learning in children's imaging. These include the requirement for very large data sets, the need to accurately label these images with a relatively small number of pediatric imagers, technical and regulatory hurdles, as well as the opaque character of convolution neural networks. We review machine learning cases in radiology including detection, classification and segmentation. Last, three pediatric radiologists from the Society for Pediatric Radiology Quality and Safety Committee share perspectives for potential areas of development.

Survey of peer review programs among pediatric radiologists: report from the SPR Quality and Safety Committee.

During the last 15 years, peer review has been widely incorporated into radiology quality improvement programs. However, current implementations are variable and carry concerns, including subjectivity of numerical scores and a sense of merely satisfying regulatory requirements. The Society for Pediatric Radiology (SPR) Quality and Safety Committee sought to evaluate the state of peer review programs in pediatric radiology practices, including implementation methods, perceived functions, strengths and weaknesses, and opportunities for improvement. We distributed an online 16-question survey to SPR members. Questions pertained to the type of peer review system, the use of numerical scores and comments, how feedback on discordances is given and received, and the use of peer learning conferences. We collected 219 responses (15% of survey invitations), 80% of which were from children's hospitals. Fifty percent of respondents said they use a picture archiving and communication system (PACS)-integrated peer review system. Comment-enhanced feedback for interpretive discordances was either very important or somewhat important to performance improvement in 86% of responses, compared to 48% with a similar perception of numerical scores. Sixty-eight percent of respondents said they either rarely or never check their numerical scores, and 82% either strongly or somewhat agreed that comments are more effective feedback than numerical scores. Ninety-three percent either strongly or somewhat agreed that peer learning conferences would be beneficial to their practice. Forty-eight percent thought that their current peer review system should be modified. Survey results demonstrate that peer review systems in pediatric radiology practices are implemented variably, and nearly half of respondents believe their systems should be modified. Most respondents prefer feedback in the form of comments and peer learning conferences, which are thought to be more beneficial for performance improvement than numerical scores.

Practical considerations when implementing peer learning conferences.

Peer learning represents a shift away from traditional peer review. Peer learning focuses on improvement of diagnostic performance rather than on suboptimal performance. The shift in focus away from random selection and toward identification of cases with valuable teaching points can encourage more active radiologist engagement in the learning process. An effective peer learning program relies on a trusting environment that lessens the fear of embarrassment or punitive action. Here we describe the shortcomings of traditional peer review, and the benefits of peer learning. We also provide tips for a successful peer learning program and examples of implementation.

The Primary Physis.

The primary physis is responsible for long bone growth in children and adolescents. Injury and physiologic or metabolic stress to the primary physis present unique radiologic findings that are important for radiologists to recognize and diagnose. Appreciation of the anatomy and histology of the primary physis forms the basis for understanding the imaging findings associated with pathologic conditions affecting the primary physis. Salter-Harris injuries, physeal bars, growth arrest lines, rickets, and focal periphyseal edema zones are common conditions with recognizable radiologic presentations. Proper diagnosis of these primary physeal conditions will aid in the treatment of affected pediatric patients.

Review of key concepts in magnetic resonance physics.

MR physics can be a challenging subject for practicing pediatric radiologists. Although many excellent texts provide very comprehensive reviews of the field of MR physics at various levels of understanding, the authors of this paper explain several key concepts in MR physics that are germane to clinical practice in a non-rigorous but practical fashion. With the basic understanding of these key concepts, practicing pediatric radiologists can build on their knowledge of current clinical MR techniques and future advances in MR applications. Given the challenges of both the increased need for rapid imaging in non-sedated children and the rapid physiological cardiovascular and respiratory motion in pediatric patients, many advances in complex MR techniques are being applied to imaging these children. The key concepts are as follows: (1) structure of a pulse sequence, (2) k-space, (3) "trade-off triangle" and (4) fat suppression. This review is the first of five manuscripts in a minisymposium on pediatric MR. The authors' goal for this review is to aid in understanding the MR techniques described in the subsequent manuscripts on brain imaging and body imaging in this minisymposium.