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ObjectiveA portable, low-field MRI system is now Food and Drug Administration cleared and has been shown to be safe and useful in adult intensive care unit settings. No neonatal studies have been performed. The objective is to assess our preliminary experience and assess feasibility of using the portable MRI system at the bedside in a neonatal intensive care unit (NICU) at a quaternary children’s hospital.Study designThis was a single-site prospective cohort study in neonates ≥2 kg conducted between October and December 2020. All parents provided informed consent. Neonates underwent portable MRI examination in the NICU with support equipment powered on and attached to the neonate during the examination. A paediatric radiologist interpreted each portable MRI examination. The study outcome variable was percentage of portable MRI examinations completed without artefacts that would hinder diagnosis. Findings were compared between portable MRI examinations and standard of care examinations.ResultsEighteen portable, low-field MRI examinations were performed on 14 neonates with an average age of 29.7 days (range 1–122 days). 94% (17 of 18) of portable MRI examinations were acquired without significant artefact. Significant intracranial pathology was visible on portable MRI, but subtle abnormalities were missed. The examination reads were concordant in 59% (10 of 17) of cases and significant pathology was missed in 12% (2 of 17) of cases.ConclusionThis single-centre series demonstrated portable MRI examinations can be performed safely with standard patient support equipment present in the NICU. These findings demonstrate that portable MRI could be used in the future to guide care in the NICU setting.Trial registration numberNCT04629469.

Imaging in hematopoietic stem cell transplantation patients is not targeted at evaluating the transplant per se. Rather, imaging is largely confined to evaluating peri-procedural and post-procedural complications. Alternatively, imaging may be performed to establish a baseline study for comparison should the patient develop certain post-procedural complications. This article looks to describe the various imaging modalities available with recommendations for which imaging study should be performed in specific complications. We also provide select imaging protocols for different indications and modalities for the purpose of establishing a set minimal standard for imaging in these complex patients.

The aim of this study was to determine if machine learning can improve the specificity of detecting transplant hepatic artery pathology over conventional quantitative measures while maintaining a high sensitivity.This study presents a retrospective review of 129 patients with transplanted hepatic arteries. We illustrate how beyond common clinical metrics such as stenosis and resistive index, a more comprehensive set of waveform data (including flow half-lives and Fourier transformed waveforms) can be integrated into machine learning models to obtain more accurate screening of stenosis and occlusion. We present a novel framework of Extremely Randomized Trees and Shapley values, we allow for explainability at the individual level.The proposed framework identified cases of clinically significant stenosis and occlusion in hepatic arteries with a state-of-the-art specificity of 65%, while maintaining sensitivity at the current standard of 94%. Moreover, through 3 case studies of correct and mispredictions, we demonstrate examples of how specific features can be elucidated to aid in interpreting driving factors in a prediction.This work demonstrated that by utilizing a more complete set of waveform data and machine learning methodologies, it is possible to reduce the rate of false-positive results in using ultrasounds to screen for transplant hepatic artery pathology compared with conventional quantitative measures. An advantage of such techniques is explainability measures at the patient level, which allow for increased radiologists' confidence in the predictions.

Non-contrast magnetic resonance (MR) angiography and MR venography techniques are gaining popularity for vascular imaging because they are faster, more forgiving and less costly compared with contrast-enhanced MR angiography. Non-contrast MR angiography also avoids gadolinium deposition, which is especially important in imaging children. Non-contrast MR angiography has an array of specific applications for numerous clinical indications. This review summarizes the non-contrast MR angiography methods and their relative advantages and disadvantages. The paper also guides the reader on which technique to consider when determining the optimal imaging modality for each individual patient.

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 (MRI) is a powerful diagnostic tool that can be optimized to display a wide range of clinical conditions. An MRI system consists of four major components: a main magnet formed by superconducting coils, gradient coils, radiofrequency (RF) coils, and computer systems. Each component has safety considerations. Unless carefully controlled, the MRI machine's strong static magnetic field could turn a ferromagnetic object into a harmful projectile or cause vertigo and headache. Switching magnetic fields in the gradients evokes loud noises in the scanner, which can be mitigated by ear protection. Gradients also generate varying magnetic fields that can cause peripheral nerve stimulation and muscle twitching. Magnetic fields produced by RF coils deposit energy in the body and can cause tissue heating (with the potential to cause skin burns). In this review, we provide an overview of the components of a typical clinical MRI scanner and its associated safety issues. We also discuss how the relationship between the scanning parameters can be manipulated to improve image quality while ensuring a safe operational environment for the patients and staff. Understanding the strengths and limitations of these parameters can enable users to choose optimal techniques for image acquisition, apply them in clinical practice, and improve the diagnostic accuracy of an MRI examination.

The ability of computed tomography (CT) to distinguish between benign congenital lung malformations and malignant cystic pleuropulmonary blastomas (PPBs) is unclear.To assess whether chest CT can detect malignant tumors among postnatally detected lung lesions in children.This retrospective multicenter case-control study used a consortium database of 521 pathologically confirmed primary lung lesions from January 1, 2009, through December 31, 2015, to assess diagnostic accuracy. Preoperative CT scans of children with cystic PPB (cases) were selected and age-matched with CT scans from patients with postnatally detected congenital lung malformations (controls). Statistical analysis was performed from January 18 to September 6, 2020. Preoperative CT scans were interpreted independently by 9 experienced pediatric radiologists in a blinded fashion and analyzed from January 24, 2019, to September 6, 2020.Accuracy, sensitivity, and specificity of CT in correctly identifying children with malignant tumors.Among 477 CT scans identified (282 boys [59%]; median age at CT, 3.6 months [IQR, 1.2-7.2 months]; median age at resection, 6.9 months [IQR, 4.2-12.8 months]), 40 cases were extensively reviewed; 9 cases (23%) had pathologically confirmed cystic PPB. The median age at CT was 7.3 months (IQR, 2.9-22.4 months), and median age at resection was 8.7 months (IQR, 5.0-24.4 months). The sensitivity of CT for detecting PPB was 58%, and the specificity was 83%. High suspicion for malignancy correlated with PPB pathology (odds ratio, 13.5; 95% CI, 2.7-67.3; P = .002). There was poor interrater reliability (κ = 0.36 [range, 0.06-0.64]; P .001) and no significant difference in specific imaging characteristics between PPB and benign cystic lesions. The overall accuracy rate for distinguishing benign vs malignant lesions was 81%.This study suggests that chest CT, the current criterion standard imaging modality to assess the lung parenchyma, may not accurately and reliably distinguish PPB from benign congenital lung malformations in children. In any cystic lung lesion without a prenatal diagnosis, operative management to confirm pathologic diagnosis is warranted.

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.

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.

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.

Magnetic resonance (MR) angiography and MR venography imaging with contrast and non-contrast techniques are widely used for pediatric vascular imaging. However, as with any MRI examination, imaging the pediatric population can be challenging because of patient motion, which sometimes requires sedation. There are multiple benefits of non-contrast MR angiographic techniques, including the ability to repeat sequences if motion is present, the decreased need for sedation, and avoidance of potential risks associated with gadolinium administration and radiation exposure. Thus, MR angiography is an attractive alternative to CT or conventional catheter-based angiography in pediatric populations. Contrast-enhanced MR angiographic techniques have the advantage of increased signal to noise. Blood pool imaging allows long imaging times that result in high-spatial-resolution imaging, and thus high-quality diagnostic images. This article outlines the technique details, indications, benefits and downsides of non-contrast-enhanced and contrast-enhanced MR angiographic techniques to assist in protocol decision-making.

Nonalcoholic fatty liver disease (NAFLD) affects up to 70% of children with obesity and has become the number one etiology for liver transplant in the United States. Early, effective intervention is critical to prevent disease progression into adulthood. Yet, it is seldom achieved through lifestyle modification alone. Thus, children must be included in NAFLD pharmacology trials, which, to date, continue to focus primarily on adult populations. This commentary serves as a call to action.

Sinusoidal obstructive syndrome, also known as hepatic veno-occlusive disease, is a potentially life-threatening complication that occurs in children undergoing haemopoietic stem-cell transplantation (HSCT). Differences in the incidence of genetic predisposition and clinical presentation of sinusoidal obstructive syndrome between children and adults have rendered the historical Baltimore and Seattle diagnostic criteria insufficient for children. In 2017, the European Society for Blood and Marrow Transplantation (EBMT) proposed the first paediatric diagnostic and severity grading guidelines for sinusoidal obstructive syndrome, intended for implementation across European centres. However, universally accepted paediatric criteria are needed to ensure prompt diagnosis, definitive treatment, and improved outcomes for children, adolescents, and young adults with sinusoidal obstructive syndrome, and to facilitate international clinical research collaboration. We convened an international panel of multidisciplinary experts including physicians with expertise in HSCT, paediatric intensive care, nephrology, hepatology, radiology, pathology, and transfusion medicine; HSCT advanced-practice providers and medical trainees; pharmacists; and translational and basic science researchers from the Pediatric Acute Lung Injury and Sepsis Investigators Network, the EBMT, the Pediatric Blood and Marrow Transplant Consortia, and several other institutions with extensive experience in sinusoidal obstructive syndrome. Panellists convened at The University of Texas, MD Anderson Cancer Center (Houston, TX, USA) in February, 2019, to evaluate the available evidence. In this expert position statement paper, we provide consensus recommendations for the international implementation of guidelines for the diagnosis, severity grading, and treatment of sinusoidal obstructive syndrome among children, adolescents, and young adults. We endorse universal adoption of paediatric diagnostic guidelines for sinusoidal obstruction syndrome as proposed by the EBMT, and provide implementation guidance for standardisation across centres; we have further proposed adjunctive use of age-appropriate organ-specific toxicity criteria for severity grading and provided prophylaxis and treatment considerations among children and adolescent and young adult patients. Key recommendations include: (1) liver biopsy, portal venous wedge pressure, and reversal of portal venous flow on Doppler ultrasonography should not be used for the routine diagnosis of sinusoidal obstructive syndrome in children, adolescents, and young adults; (2) platelet refractoriness can be defined as a corrected count increment of less than 5000-7500 following at least two sequential ABO-compatible fresh platelet transfusions; (3) hepatomegaly is best defined as an absolute increase of at least 1 cm in liver length at the midclavicular line; and if a baseline measurement is not available, hepatomegaly can be defined as greater than 2 SDs above normal for age; and (4) the presence and volume of ascites can be categorised as mild (minimal fluid by liver, spleen, or pelvis), moderate (1 cm fluid), or severe (fluid in all three regions with1 cm fluid in at least two regions).

Ultrasound elastography is an easy, relatively affordable, noninvasive method that can be used to assess for hepatic fibrosis. The aim of this article is to present an introduction to ultrasound elastography and provide case examples to show when its use can be beneficial.

Necrotising enterocolitis (NEC) is a leading cause of death and disability in preterm newborns. Early diagnosis through non-invasive investigations is a crucial strategy that can significantly improve outcomes. Hence, this review gives particular attention to the emerging role of abdominal ultrasound (AUS) in the early diagnosis of NEC, its performance against abdominal radiograph and the benefits of AUS use in daily practice. AUS has been used in the diagnosis and management of NEC for a couple of decades. However, its first-line use has been minimal, despite growing evidence demonstrating AUS can be a critical tool in the early diagnosis and management of NEC. In 2018, the NEC group of the International Neonatal Consortium recommended using AUS to detect pneumatosis and/or portal air in preterm NEC as part of the ‘Two out of three’ model. To facilitate widespread adoption, and future improvement in practice and outcomes, collaboration between neonatologists, surgeons and radiologists is needed to generate standard operating procedures and indications for use for AUS. The pace and scale of the benefit generated by use of AUS can be amplified through use of computer-aided detection and artificial intelligence.

Acute appendicitis represents the most common abdominal surgical urgency/emergency in children. Imaging remains a central tool in the diagnosis of acute appendicitis and has been shown to facilitate management and decrease the rate of negative appendectomies. The initial consideration for imaging in a child with suspected acute appendicitis is based on clinical assessment, which can be facilitated with published scoring systems. The level of clinical risk (low, intermediate, high) and the clinical scenario (suspicion for complication) define the need for imaging and the optimal imaging modality. In some situations, no imaging is required, while in others ultrasound, CT, or MRI may be appropriate. This review frames the presentation of suspected acute appendicitis in terms of the clinical risk and also discusses the unique situations of the equivocal or nondiagnostic initial ultrasound examination and suspected appendicitis with suspicion for complication (eg, bowel obstruction). 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.

Clinical decision support has been identified by the United States government as a method to decrease inappropriate imaging exams and promote judicious use of imaging resources. The adoption of this method will be incentivized by requiring appropriate use criteria to qualify for Medicare reimbursement starting in January 2020. While Medicare reimbursement is unlikely to directly impact pediatric imaging because of largely disparate patient populations, insurance providers typically use Medicare to benchmark their reimbursement guidelines. Therefore soon after their adoption these guidelines could become relevant to pediatric imaging. In this article we discuss how pediatric imaging was initially underrepresented in the clinical decision support realm, and how this was addressed by a subcommittee involving both American College of Radiology and Society for Pediatric Radiology members. We also present the experience of implementing clinical decision support software at two standalone pediatric hospitals and summarize the lessons learned from these deployments.

Clinical decision support is a way to decrease inappropriate imaging exams and promote judicious use of imaging resources. The adoption of clinical decision support will be incentivized by requiring the use of approved mechanisms to qualify for Medicare reimbursement starting in January 2020. Insurance providers base their reimbursement policies on Medicare, so clinical decision support could soon become relevant to pediatric imaging. We present the process behind the American College of Radiology (ACR) Appropriateness Criteria (a set of appropriate use criteria developed by the ACR) that will form the basis for software that can be used to fulfill the criteria for clinical decision support. For most organizations, this software is expected to be the easiest way to implement clinical decision support. Clinical decision support will affect how providers order imaging exams. This article should help readers understand how clinical decision support is expected to change the practice of the ordering providers, how the ACR Appropriateness Criteria are related to clinical decision support and how the ACR Appropriateness Criteria are developed. This will help the interpreting radiologist better communicate with the referring clinician, including informing the latter about how the clinical decision support software is making decisions.

BACKGROUND Hepatic sinusoidal obstruction syndrome (SOS) is a potentially fatal complication after hematopoietic stem cell transplantation (HSCT). Current clinical guidelines state that spectral Doppler changes occur late in the disease, and imaging is only useful for confirming SOS diagnosis. OBJECTIVE Our primary objective was to examine abdominal ultrasound variables as predictors of development of SOS in pediatric HSCT patients. MATERIALS AND METHODS A single-center cohort retrospective study was conducted on patients aged 0 to 21 years who underwent HSCT between September 2001 and May 2017 at our institution. Patients were excluded if they did not have abdominal ultrasounds after HSCT. Clinical, demographic, grayscale, and spectral Doppler liver ultrasound findings were evaluated. We modeled the odds of SOS diagnosis within 100 days after HSCT as a function of each of the 15 ultrasound variables. RESULTS A total of 333 patients received an HSCT. One hundred forty subjects had ultrasound data available. Thirty-two patients developed SOS, and 9 of these patients died. Sinusoidal obstruction syndrome odds more than double per 1-SD increase in peak systolic velocity in common hepatic artery or left hepatic artery and more than triple per 1-SD decrease in main portal vein velocity or change in ascites severity. Several ultrasound variables were statistically significant predictors in the Cox models for time to SOS diagnosis. CONCLUSION Several ultrasound variables can be used as predictors for a patient's risk of developing SOS. The strongest predictors are ascites severity, main portal vein velocity, common hepatic artery peak systolic velocity, and left hepatic artery peak systolic velocity.

BACKGROUND: Pediatric lung lesions are a group of mostly benign pulmonary anomalies with a broad spectrum of clinical disease and histopathology. Our objective was to evaluate the characteristics of children undergoing resection of a primary lung lesion and to identify preoperative risk factors for malignancy. METHODS: A retrospective cohort study was conducted by using an operative database of 521 primary lung lesions managed at 11 children’s hospitals in the United States. Multivariable logistic regression was used to examine the relationship between preoperative characteristics and risk of malignancy, including pleuropulmonary blastoma (PPB). RESULTS: None of the 344 prenatally diagnosed lesions had malignant pathology (P < .0001). Among 177 children without a history of prenatal detection, 15 (8.7%) were classified as having a malignant tumor (type 1 PPB, n = 11; other PPB, n = 3; adenocarcinoma, n = 1) at a median age of 20.7 months (interquartile range, 7.9–58.1). Malignancy was associated with the DICER1 mutation in 8 (57%) PPB cases. No malignant lesion had a systemic feeding vessel (P = .0427). The sensitivity of preoperative chest computed tomography (CT) for detecting malignant pathology was 33.3% (95% confidence interval [CI]: 15.2–58.3). Multivariable logistic regression revealed that increased suspicion of malignancy by CT and bilateral disease were significant predictors of malignant pathology (odds ratios of 42.15 [95% CI, 7.43–340.3; P < .0001] and 42.03 [95% CI, 3.51–995.6; P = .0041], respectively). CONCLUSIONS: In pediatric lung masses initially diagnosed after birth, the risk of PPB approached 10%. These results strongly caution against routine nonoperative management in this patient population. DICER1 testing may be helpful given the poor sensitivity of CT for identifying malignant pathology.

Non-contrast magnetic resonance (MR) angiography and MR venography techniques are gaining popularity for vascular imaging because they are faster, more forgiving and less costly compared with contrast-enhanced MR angiography. Non-contrast MR angiography also avoids gadolinium deposition, which is especially important in imaging children. Non-contrast MR angiography has an array of specific applications for numerous clinical indications. This review summarizes the non-contrast MR angiography methods and their relative advantages and disadvantages. The paper also guides the reader on which technique to consider when determining the optimal imaging modality for each individual patient.

Purpose: Foreign body aspiration is difficult to diagnose because many aspirated foreign bodies are low density or radiolucent. Digital radiographs (DR) are poor at detecting radiolucent foreign bodies. Digital tomosynthesis (DTS) has been shown to be ideally suited for applications where DR is insensitive and the increased dose from computed tomography (CT) is not justified. Our objective was to determine if DTS can be a practical alternative to DR and CT in the diagnosis of foreign body aspiration. Approach: A phantom approximating the densities of a pediatric chest was constructed. Radiolucent foreign bodies were placed in the airways. Seven pediatric radiologists assessed DTS and DR images with and without simulated breathing motion. Two rounds were performed with fixed exposure techniques and then automatic exposure control techniques. Interobserver agreement was evaluated using Fleiss’ kappa. Results: DTS and DR images using fixed exposure techniques performed very poorly with accuracies of 42% to 60%. DTS with automatic exposure control techniques increased accuracy to 84% for a stationary phantom, but the accuracy dropped to 70% in a phantom with simulated motion. DTS outperformed DR, with DR accuracies of 60% and 63% for stationary simulations and motion, respectively. Interobserver agreement was poor with Fleiss’ kappa of 0.476. Conclusion: DTS is superior to DR for radiolucent foreign body detection. However, the overall accuracy and interobserver agreement are likely too low for this modality to be clinically useful.

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 (MRI) is a powerful diagnostic tool that can be optimized to display a wide range of clinical conditions. An MRI system consists of four major components: a main magnet formed by superconducting coils, gradient coils, radiofrequency (RF) coils, and computer systems. Each component has safety considerations. Unless carefully controlled, the MRI machine's strong static magnetic field could turn a ferromagnetic object into a harmful projectile or cause vertigo and headache. Switching magnetic fields in the gradients evokes loud noises in the scanner, which can be mitigated by ear protection. Gradients also generate varying magnetic fields that can cause peripheral nerve stimulation and muscle twitching. Magnetic fields produced by RF coils deposit energy in the body and can cause tissue heating (with the potential to cause skin burns). In this review, we provide an overview of the components of a typical clinical MRI scanner and its associated safety issues. We also discuss how the relationship between the scanning parameters can be manipulated to improve image quality while ensuring a safe operational environment for the patients and staff. Understanding the strengths and limitations of these parameters can enable users to choose optimal techniques for image acquisition, apply them in clinical practice, and improve the diagnostic accuracy of an MRI examination.

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation. Early diagnosis and, subsequently, earlier intervention have been shown to be beneficial to clinical outcomes. Diagnostic criteria from the European Society for Blood and Marrow Transplantation include recommendations on the use of imaging for diagnosis. This review discusses evidence on the use of imaging in the management of VOD/SOS and how imaging biomarkers can contribute to earlier diagnosis/treatment.

Imaging plays in important role in the evaluation of the acutely limping child. The decision-making process about initial imaging must consider the level of suspicion for infection and whether symptoms can be localized. The appropriateness of specific imaging examinations in the acutely limping child to age 5 years is discussed with attention in each clinical scenario to the role of radiography, ultrasound, nuclear medicine, computed tomography, and magnetic resonance imaging. Common causes of limping such as toddler's fracture, septic arthritis, transient synovitis, and osteomyelitis are discussed. 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.

Hematuria is the presence of red blood cells in the urine, either visible to the eye (macroscopic hematuria) or as viewed under the microscope (microscopic hematuria). The clinical evaluation of children and adolescents with any form of hematuria begins with a meticulous history and thorough evaluation of the urine. The need for imaging evaluation depends on the clinical scenario in which hematuria presents, including the suspected etiology. Ultrasound and CT are the most common imaging methods used to assess hematuria in children, although other imaging modalities may be appropriate in certain instances. This review focuses on the following clinical variations of childhood hematuria: isolated hematuria (nonpainful, nontraumatic, and microscopic versus macroscopic), painful hematuria (ie, suspected nephrolithiasis or urolithiasis), and renal trauma with hematuria (microscopic versus macroscopic). 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.

Interpretation of radiolucent foreign bodies (FBs) is a common task charged to pediatric radiologists. The use of a motion compensated technique to decrease breathing motion on images would greatly decrease overall exposure to ionizing radiation and increase access to treatment yielding a great impact on clinical care. This study reports on the methodology and materials used to construct an in-house anthropomorphic phantom for investigating image quality in digital tomosynthesis protocols for volumetric imaging of the pediatric airway. Availability and cost of possible substitute materials were considered and simplifying assumptions were made. Two different modular phantoms were assembled in coronal slab layers using materials designed to approximate a one- and three-year-old thorax at diagnostic photon energies for use with digital tomosynthesis protocols such as those offered on GE’s VolumeRAD application. Exposures were made using both phantoms with inserted food particles inside an oscillating airway. The goal of the phantom is to help evaluate (1) whether the currently used protocol is sufficient to image the airway despite breathing motion and (2) whether it is not, to find the optimal protocol by testing various commercially available protocols using this phantom. The affordable construction of the pediatric sized phantom aimed at optimizing GE’s VolumeRAD protocol for airway foreign body imaging is demonstrated in this study which can be used to test VolumeRAD’s ability to image the airways with and without a low-density foreign body within the airways.

Necrotizing enterocolitis (NEC) is a devastating inflammatory disease of the intestinal tract that represents a significant source of morbidity and mortality in preterm infants. Imaging of the abdomen is valuable for timely diagnosis and close monitoring of disease progression in NEC. Bowel ultrasound (US) is increasingly being recognized as an important imaging tool for evaluating NEC that provides additional detail than plain abdominal radiographs. To identify bowel US findings associated with surgical management or death in infants with NEC. We searched Embase, PubMed, and the Cumulative Index to Nursing and Allied Health Literature for studies investigating the association between bowel US findings and surgical management or death in NEC. Selected articles were evaluated for quality of study methodology using the Newcastle-Ottawa Scale, and aggregate statistics for odds ratio (OR) and 95% confidence interval were calculated. Of 521 articles reviewed, 11 articles comprising 748 infants were evaluated for quality. Nine of the studies were retrospective and from single-center experiences. Pooled analysis showed that focal fluid collections (OR 17.9, 3.1–103.3), complex ascites (OR 11.3, 4.2–30.0), absent peristalsis (OR 10.7, 1.7–69.0), pneumoperitoneum (OR 9.6, 1.7–56.3), bowel wall echogenicity (OR 8.6, 3.4–21.5), bowel wall thinning (OR 7.11.6–32.3), absent perfusion (OR 7.0, 2.1–23.8), bowel wall thickening (OR 3.9, 2.4–6.1) and dilated bowel (OR 3.5, 1.8–6.8) were associated with surgery or death in NEC. In contrast, portal venous gas (OR 3.0, 0.8–10.6), pneumatosis intestinalis (OR 2.1, 0.9–5.1), increased bowel perfusion (OR 2.6, 0.6–11.1) and simple ascites (OR 0.54, 0.1–2.5) were not associated with surgery or death. This meta-analysis identified several bowel US findings that are associated and not associated with surgery or death in NEC. Bowel US may be useful for early identification of high-risk infants with NEC who may benefit from more aggressive treatment, including surgery. Future studies are needed to determine whether the addition of bowel US in NEC evaluation would improve outcomes.

Background: Pediatric cystic lung lesions represent a rare group of predominantly benign pulmonary anomalies with a broad spectrum of clinical disease and histopathology. We aimed to examine the clinical presentation, pathology data, and diagnostic evaluation of children undergoing resection of a cystic lung lesion diagnosed after birth. Methods: A multisite observational cohort study was conducted of children undergoing resection of a postnatally diagnosed primary cystic lung lesion between Jan 1, 2009 and Dec 31, 2015 at one of 11 United States children’s hospitals (Midwest Pediatric Surgery Consortium). Clinical presentation, perioperative findings, and pathologic diagnosis were reviewed and analyzed using non-parametric bivariate and multivariable logistic regression models. Findings: Of 521 children with resected lung lesions, 177 (34·0%) underwent resection for a lesion that was not diagnosed prenatally. Operations was performed with low morbidity at median ages of 4.4 months [interquartile range (IQR), 0·9-28·7], 10·9 months (IQR, 7·6-151·2), and 42·3 months (IQR, 11·1-86·2) for respiratory symptoms (n=89, 50·6%), asymptomatic disease (n=35, 19·9%), and pneumonia history (n=54, 30.7%), respectively. The most common pathologic diagnosis was congenital pulmonary airway malformation (n=59, 34·3%). Fifteen (8·5%) were classified as malignant tumors [type 1 pleuropulmonary blastoma (PPB), n=11; other PPB, n=3; adenocarcinoma, n=1) at a median resection age of 20.7 months (IQR, 7·9-58·1). The sensitivity of preoperative chest CT for detecting malignant pathology was 33.3% (95% CI: 15·2-58·3). Multivariable logistic regression showed that increased suspicion of malignancy by CT and bilateral disease were significant predictors of malignant pathology [odds ratios, 42·15 (95% CI: 7·43-340·3, p

Despite decades of exploration into necrotising enterocolitis (NEC), we still lack the capacity to accurately diagnose the disease to improve outcomes in its management. Existing diagnostics struggle to delineate NEC from other neonatal intestinal diseases; it is also unable to highlight those likely to deteriorate to needing emergency life-saving surgery before it is too late. The diagnosis of NEC is heavily dependent on interpretation of radiological findings, especially abdominal radiography (AR) and abdominal ultrasound (AUS). Inter-expert variability in interpreting AR imaging, and in the case of AUS, performing and interpreting the test, remains an unresolved challenge. With the compounding impact of the shrinking radiology workforce, a novel approach is imperative. Computer assisted detection (CAD) and classification of abnormal pathology in medical imaging is a rapidly evolving field of clinical and biomedical research. This technology is widely used as a preliminary screening tool. This research paper proposes a deep learning-based model to classify AR images in an automated manner, generating class activation maps (CAM) from various imaging features consistent with NEC pathology, as agreed by expert consensus papers (in neonatology and paediatric radiology). It also compares it with conventional machine learning methods. The suggested model aims to produce heatmaps for various imaging features to highlight NEC pathology in AR (or in future AUS). Once the model is trained, validation is done through quantitative measures and visually by the attending radiologist (clinician) reviewing the validity of the colour maps highlighting the pathology of the AR image (future extension to AUS). As the volume of imaging data is increasing year by year, CAD can be a key strategy to assist radiology departments meet service needs. This technology can greatly assist in screening for NEC, improving the detection of NEC and potentially aid in the earlier identification of disease. Furthermore, it can fast track research cost effectively by creating big data through the automatic labeling of imaging data to create big-data for NEC databases.

Objectives This study evaluates the sensitivity and specificity of stenosis index (SI), which accounts for the entire spectral Doppler waveform, to detect significant transplant hepatic arterial stenosis. Materials and Methods In this institutional review board–approved, HIPAA compliant study, we retrospectively analyzed 69 patients who had catheter angiography for suspected transplant hepatic arterial stenosis (THAS) between January 2006 and December 2010; all patients had Doppler ultrasound within 30 days before angiography. Patients with angiographic stenosis requiring intervention were considered positive for THAS. Stenosis index was calculated from each patient's spectral Doppler ultrasound images by obtaining the ratio of the area under the high-frequency signal to low-frequency signal in the spectral Doppler. Resistive index (RI) and pulsatility index (PI) were also calculated. Receiver operator curve analysis was performed and the area under the curve (AUC) was compared among the three metrics. Results Forty-eight of 69 patients had THAS by angiography requiring intervention; 21patients had no angiographic evidence of THAS. SI was significantly different (P

Acute appendicitis represents the most common abdominal surgical urgency/emergency in children. Imaging remains a central tool in the diagnosis of acute appendicitis and has been shown to facilitate management and decrease the rate of negative appendectomies. The initial consideration for imaging in a child with suspected acute appendicitis is based on clinical assessment, which can be facilitated with published scoring systems. The level of clinical risk (low, intermediate, high) and the clinical scenario (suspicion for complication) define the need for imaging and the optimal imaging modality. In some situations, no imaging is required, while in others ultrasound, CT, or MRI may be appropriate. This review frames the presentation of suspected acute appendicitis in terms of the clinical risk and also discusses the unique situations of the equivocal or nondiagnostic initial ultrasound examination and suspected appendicitis with suspicion for complication (eg, bowel obstruction). 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.

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.

Ultrasound is one of the most important imaging modalities in pediatric imaging because of its accessibility, portability, lack of ionizing radiation, and ability to generally perform examinations without need for sedation. Ultrasound elastography can measure the stiffness of various tissues. This review article aims to discuss how ultrasound elastography has performed in evaluating multiple pathologies in the pediatric population. The best studied pediatric applications are in liver diseases such as fibrosis, biliary atresia, and hepatic vascular congestion. Measuring muscle stiffness in cerebral palsy is the most promising pediatric musculoskeletal application, but many other applications are in the early stages of research. Other applications in pediatric small organ imaging have been explored and still need more study before gaining clinical relevance.

Imaging plays in important role in the evaluation of the acutely limping child. The decision-making process about initial imaging must consider the level of suspicion for infection and whether symptoms can be localized. The appropriateness of specific imaging examinations in the acutely limping child to age 5 years is discussed with attention in each clinical scenario to the role of radiography, ultrasound, nuclear medicine, computed tomography, and magnetic resonance imaging. Common causes of limping such as toddler's fracture, septic arthritis, transient synovitis, and osteomyelitis are discussed. 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.

Clinical decision support has been identified by the United States government as a method to decrease inappropriate imaging exams and promote judicious use of imaging resources. The adoption of this method will be incentivized by requiring appropriate use criteria to qualify for Medicare reimbursement starting in January 2020. While Medicare reimbursement is unlikely to directly impact pediatric imaging because of largely disparate patient populations, insurance providers typically use Medicare to benchmark their reimbursement guidelines. Therefore soon after their adoption these guidelines could become relevant to pediatric imaging. In this article we discuss how pediatric imaging was initially underrepresented in the clinical decision support realm, and how this was addressed by a subcommittee involving both American College of Radiology and Society for Pediatric Radiology members. We also present the experience of implementing clinical decision support software at two standalone pediatric hospitals and summarize the lessons learned from these deployments.

Clinical decision support is a way to decrease inappropriate imaging exams and promote judicious use of imaging resources. The adoption of clinical decision support will be incentivized by requiring the use of approved mechanisms to qualify for Medicare reimbursement starting in January 2020. Insurance providers base their reimbursement policies on Medicare, so clinical decision support could soon become relevant to pediatric imaging. We present the process behind the American College of Radiology (ACR) Appropriateness Criteria (a set of appropriate use criteria developed by the ACR) that will form the basis for software that can be used to fulfill the criteria for clinical decision support. For most organizations, this software is expected to be the easiest way to implement clinical decision support. Clinical decision support will affect how providers order imaging exams. This article should help readers understand how clinical decision support is expected to change the practice of the ordering providers, how the ACR Appropriateness Criteria are related to clinical decision support and how the ACR Appropriateness Criteria are developed. This will help the interpreting radiologist better communicate with the referring clinician, including informing the latter about how the clinical decision support software is making decisions.

Foreign body (FB) ingestion is a common reason for emergency department visits, affecting more than 80,000 children in the United States annually. Whereas most ingested FBs are coins or other radiopaque objects, some are radiolucent FBs such as food. Digital tomosynthesis (DTS) is a radiographic technique that produces cross-sectional images with in-plane resolution similar to that of traditional radiographs. Our pilot study evaluated the sensitivity and specificity of DTS to detect FB in comparison to esophagram and clinical impression.This was a retrospective review on patients aged 0 to 18 years with suspected esophageal FB who received an esophagram with DTS at our institution between January 2014 and June 2016. Digital tomosynthesis images were analyzed by 3 readers for identification of FB impaction and compared with esophagram and discharge diagnosis. This study was approved by our local institutional review board.A total of 17 patients underwent an esophagography with DTS for suspected esophageal FB, of which 9 (53%) were suspected of having an FB on esophagram. Compared with esophagram, DTS had a sensitivity of 44%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 62%. Compared with clinical impression, DTS had a sensitivity of 33%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 38%.This pilot study showed that chest DTS has a very high positive predictive value, compared with esophagram and clinical impression, in detecting radiolucent esophageal FBs in children. Chest DTS is a promising modality for ruling in the presence of a radiolucent esophageal FB.

Introduction Hepatic sinusoidal obstruction syndrome (SOS) is a complication of hematopoietic stem cell transplantation (HSCT). Severe and very severe SOS is associated with multi-organ failure and has ∼60% mortality. SOS is classified into mild, moderate, severe and very severe based on new European Society for Blood and Marrow Transplantation (EBMT) criteria. Defibrotide treatment is recommended for severe and very severe patients. Objective Our primary objective was to determine if hepatic ultrasound shear wave elastography (SWE) can predict SOS severity in pediatric HSCT patients. Methods This is a multi-site prospective cohort study evaluating the use of SWE in pediatric HSCT patients (0-21 years) from 10/2015 to 3/2018 at 2 pediatric institutions. Site 1 subjects underwent 1 SWE within 10-days prior to start of conditioning regimen and at days +5 and +14 after HSCT. Site 2 enrolled subjects at the time of clinical suspicion for SOS and subjects received SWE examinations every other day up to 10 exams during their inpatient stay. We examined 11 time-varying variables including weight, hepatomegaly, ascites, SWE and various Doppler ultrasound variables as predictors of maximum EBMT criteria severity grade. We used the median to summarize the SWE values. Missing data on explanatory variables ( Results 55 subjects were enrolled. Most patients were male (n=33, 55%) with a median age of 8 (range 0-20) years. 21 (35%) patients developed SOS, 15 (25%) had severe or greater disease by EBMT criteria. Busulfan use is associated with an average increase of 0.6 in EBMT grade, and a 100 cm/s decrease in main portal vein velocity is associated with an average increase of 1.3 in EBMT grade. Hepatomegaly, ascites, and higher SWE stiffness also appear to be associated with greater SOS severity (p 1.95 m/s was 87.5% sensitive and 85% specific for severe or very severe SOS. Seven of eight patients with severe or very severe SOS had SWE >1.95 m/s two to thirteen days before the date of severe SOS grading. Conclusion In a group of 12 clinical and ultrasound variables, SWE velocity was an excellent predictor of the patient developing severe SOS. SWE was able to predict severe SOS 2 to 13 days before the EBMT criteria with 87.5% sensitivity and 85% specificity.

There is an established association between tetralogy of Fallot and partial anomalous pulmonary venous connections. This association is important because surgically repaired tetralogy patients have increased risk of right heart failure. We hypothesize that partial anomalous venous connections increase right ventricular volumes and worsen right ventricular failure.We reviewed cardiac MRI exams performed at a tertiary pediatric hospital from January 2005 to January 2014. We identified patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection. We used age- and gender-matched repaired tetralogy patients without partial anomalous pulmonary venous connection as controls. We analyzed the MRI results and surgical course and performed comparative statistics to identify group differences.There were eight patients with repaired tetralogy and unrepaired partial anomalous pulmonary venous connection and 16 controls. In all cases, the partial anomalous pulmonary venous connection was not detected on preoperative echocardiography. There were no significant differences in surgical course and body surface area between the two groups. Repaired tetralogy patients with unrepaired partial anomalous pulmonary venous connection showed significantly higher indexed right ventricular end diastolic volume (149 ± 33 mL/m(2) vs. 118 ± 30 mL/m(2)), right ventricle to left ventricle size ratios (3.1 ± 1.3 vs. 1.9 ± 0.5) and a higher incidence of reduced right ventricular ejection fraction compared to controls (3/8 vs. 0/16).Repaired tetralogy of Fallot with unrepaired partial anomalous pulmonary venous connection is associated with reduced right ventricular ejection fraction and more significant right ventricular dilation.

Radiographic evaluation for necrotizing enterocolitis (NEC) often yields nonspecific findings. Bowel ultrasound (BUS) provides additional information beyond that of abdominal radiographs and may be helpful in the diagnosis of NEC in neonates. We systematically reviewed and aggregated existing literature to get a better estimate of diagnostic accuracy of BUS in the diagnosis of NEC. A literature search was performed using PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature to identify studies in which infants with clinically suspected NEC were evaluated using BUS. Studies that used modified Bell staging criteria as the reference standard were included. Study quality was assessed, and pooled sensitivity and specificity of various BUS findings for diagnosing NEC were determined. Six articles with a total of 462 patients met eligibility and inclusion criteria. There was heterogeneity in BUS findings evaluated across studies. Ultrasound detection of classic signs of NEC (portal venous gas, pneumatosis, and free air) had pooled sensitivities ranging from 0.27 to 0.48 and pooled specificities ranging from 0.91 to 0.99. Bowel wall thinning and absent peristalsis had overall low sensitivity (0.22 and 0.30) but high specificity (0.96 and 0.96) for NEC. Assessment of abdominal fluid, which included ascites and focal fluid collection, also had overall low sensitivity and high specificity (simple ascites: 0.45 and 0.92; focal fluid collection: 0.19 and 0.98). In summary, individual BUS findings have low sensitivity and high specificity for diagnosis of NEC. Bowel ultrasound may be a useful adjunct to plain abdominal radiographs in the evaluation of infants with clinical suspicion of NEC.

Sinusoidal obstruction syndrome (SOS) is a potentially fatal complication of hematopoietic stem cell transplantation (HSCT). Traditional ultrasound (US) has poor sensitivity and specificity. US shear wave elastography (SWE) is a newer technology that measures liver stiffness. This is a single-institution, prospective cohort study evaluating SWE in patients younger than 21 years who received HSCT from December 2015 through June 2017. SOS was defined using the modified Seattle criteria. Subjects had US with SWE at three scheduled time points. t-tests were used to assess for difference between the groups and ROC curves were generated. Twenty-five patients were included. Five subjects developed SOS. At day +5 HSCT, SOS patients had SWE velocities that increased by 0.25 ± 0.21 m/s compared to 0.02 ± 0.18 in patients without SOS (p = 0.020). At day +14, SOS patients had SWE velocities that significantly increased by 0.91 m/s ± 1.14 m/s compared to 0.03 m/s ± 0.23 m/s in patients without SOS (p = 0.010). SWE SOS diagnosis occurred on average 9 and 11 days before clinical and conventional US diagnosis, respectively. Patients who develop SOS have increased liver stiffness compared to patients who do not develop SOS. SWE changes occur before other imaging and clinical findings of SOS.

Foreign body ingestion is a common indication for imaging children. Ultrasound can be a useful adjunct to serial radiographs for evaluation of foreign bodies in the enteric tract. This case report describes a child who swallowed a single magnetic rock. Follow-up radiographs 4 days later could not determine progression of the foreign body beyond the stomach. Ultrasound was used to locate it, showing a structure with unexpected posterior reverberation artifact in the stomach. This was correlated with a similar magnet in a water bath demonstrating identical reverberation artifact. This report discusses the underlying factors for the different sonographic appearances and associated ultrasound artifacts of foreign bodies. This knowledge is important when performing sonography as adjunct modality for identification of foreign bodies in the gastrointestinal tract.