Efficacy and safety of coronary computed tomography angiography in diagnosing coronary lesions in children.

INTRODUCTION: Identification of paediatric coronary artery abnormalities is challenging. We studied whether coronary artery CT angiography can be performed safely and reliably in children. MATERIALS: Retrospective analysis of consecutive coronary CT angiography scans was performed for image quality and estimated radiation dose. Both factors were assessed for correlation with electrocardiographic-gating technique that was protocoled on a case-by-case basis, radiation exposure parameters, image noise artefact parameters, heart rate, and heart rate variability. RESULTS: Sixty scans were evaluated, of which 96.5% were diagnostic for main left and right coronaries and 91.3% were considered diagnostic for complete coronary arteries. Subjective image quality correlated significantly with lower heart rate, increasing patient age, and higher signal-to-noise ratio. Estimated radiation dose only correlated significantly with choice of electrocardiographic-gating technique with median doses as follows: 2.42 mSv for electrocardiographic-gating triggered high-pitch spiral technique, 5.37 mSv for prospectively triggered axial sequential technique, 3.92 mSv for retrospectively gated technique, and 5.64 mSv for studies which required multiple runs. Two scans were excluded for injection failure and one for protocol outside the study scope. Five non-diagnostic cases were attributed to breathing motion, scanning prior to peak contrast enhancement, or scan acquisition during the incorrect portion of the R-R interval. CONCLUSIONS: Diagnostic-quality coronary CT angiography can be performed reliably with a low estimated radiation exposure by tailoring each scan protocol to the patient's body habitus and heart rate. We propose coronary CT angiography is a safe and effective diagnostic modality for coronary artery abnormalities in children.

Current utilization of pediatric postmortem imaging in North America: a questionnaire-based survey.

BACKGROUND: Postmortem imaging is used more widely as the number of conventional autopsies has decreased over the last several decades. It is widely accepted in Europe, Asia and Oceania, but there has been a delay in acceptance in North America. Education, scanning protocols, resourcing and clinical incentives are needed to support this emerging field. OBJECTIVE: To determine the use of postmortem imaging and define perceived barriers to its implementation with the goal of expanding postmortem imaging in the United States and Canada. MATERIALS AND METHODS: We sent an online survey to active members of the Society for Pediatric Radiology (SPR) addressing the use of postmortem imaging, indications, readers, practical aspects, anticipated barriers and potential solutions to more widespread use. RESULTS: More than 50% of the 50 institutions that returned surveys used postmortem computed tomography; 24% used postmortem magnetic resonance imaging. Most postmortem imaging cases were read by radiologists. Fewer than 50% had formal correlation with autopsy results or an established relationship with the local medical examiner. Seven institutions reported reimbursement for postmortem imaging. Major barriers to postmortem imaging included lack of funding and lack of interest among clinicians. Funding and education were seen as important issues requiring attention. CONCLUSION: While most responding institutions provide pediatric postmortem imaging, the modalities, protocols, reporting procedures and clinical correlation vary widely. A lack of funding and few opportunities for education are limiting factors. Attention to these issues along with active support from the SPR are seen as potential solutions to recognize the value and promote widespread acceptance of postmortem imaging.

Magnetic resonance imaging of Müllerian anomalies in girls: concepts and controversies.

Female Müllerian anomalies are the result of failure of formation, fusion or resorption of the Müllerian ducts and are relatively common, with a prevalence of 5.5-7.0% in the general population. While some of these anomalies are asymptomatic, those presenting with obstruction require accurate identification for optimal clinical management including potential surgical treatment. MRI is a useful adjunct to sonography in the evaluation of Müllerian anomalies, typically allowing a more complete characterization of the malformation. Technical aspects, embryologic concepts and controversies regarding classification systems are highlighted in this review. Several Müllerian anomalies are discussed and illustrated in more detail utilizing various cases with pelvic MRI studies.

Navigating the perils and pitfalls of pediatric forensic postmortem imaging in the United States.

Postmortem CT is widely used in the general adult and military populations. It is used extensively in pediatric death investigations in Europe and Asia, but distinctive challenges are encountered when launching a postmortem imaging program in the United States. We describe the issues we have encountered specific to establishing a pediatric postmortem imaging service in this country and propose potential solutions.

Tibial Intraosseous Insertion in Pediatric Emergency Care: A Review Based upon Postmortem Computed Tomography.

Objective: The proximal tibia is a recommended and commonly used site for pediatric emergency intraosseous vascular access (IO). During forensic whole body postmortem computed tomography (PMCT), we evaluated accuracy of emergency placement of tibial IO access.Methods: We conducted a retrospective review of 92 state medical examiner cases to assess presence and placement of tibial IO needles. Insertions were classified as successful (needle tip in the medullary portion of the bone) or unsuccessful (all other non-medullary placements) based upon position of the needle tip. Medical records were reviewed for patient age, equipment, and where an insertion was attempted, as well as if IO placement occurred in a prehospital or hospital environment.Results: Thirty-one cases with 42 tibial devices (aged 3 weeks to 16 years, median 4 months) were identified. In 25 insertions (60%), the needle tip was in satisfactory position. In 17 placements (40%), needle tip was unsatisfactory and included tibia perforation (6), tip embedded in the cortex (6), and needle missed the bone (5). In patients older than 6 months, all six placements of a 15-mm needle were successful. In infants age 6 months or younger, 14 placements (56%) were successful and 11 (44%) unsuccessful. The 25-mm IO needle was successfully placed in five of six children older than 6 months. In infants age 6 months or younger, the 25-mm needle was unsuccessfully placed in five of five attempts.Conclusion: In infants 6 months of age or younger, tibial IO needle insertion had a 53% failure rate (non-medullary placement). Failures occur during both prehospital and emergency department care. In infants age 6 months or younger, use of a 25-mm needle should be avoided. Procedures for IO insertion in infants age 6 months or younger should be reviewed and modification considered.

Pediatric postmortem computed tomography: initial experience at a children's hospital in the United States.

Postmortem CT might provide valuable information in determining the cause of death and understanding disease processes, particularly when combined with traditional autopsy. Pediatric applications of postmortem imaging represent a new and rapidly growing field. We describe our experience in establishing a pediatric postmortem CT program and present a discussion of the distinct challenges in developing this type of program in the United States of America, where forensic practice varies from other countries. We give a brief overview of recent literature along with the common imaging findings on postmortem CT that can simulate antemortem pathology.

Pulmonary embolus as cause of death in an adolescent: demonstration on postmortem CT.

Computed tomography (CT) is widely accepted in adult forensic death investigations (determination of cause and manner of death) but is only beginning to play a larger role in the cause of death determination in infants and children. We present a case of an adolescent with nephrotic syndrome who sustained cardiac arrest and died in the emergency department. A postmortem CT was requested by the state Office of the Medical Examiner as part of the medicolegal death investigation. Postmortem CT showed a saddle pulmonary embolus that was confirmed on conventional autopsy, demonstrating a natural manner of death.

Magnetic resonance imaging of acquired disorders of the pediatric female pelvis other than neoplasm.

Transabdominal US remains the primary screening imaging modality of the pediatric female pelvis. However, MRI has become an invaluable adjunct to US in recent years. MRI offers superb soft-tissue contrast resolution that allows for detailed evaluation, particularly of the ovaries and their associated pathology. MRI can yield diagnostic information that is similar to or even better than that of US, especially in nonsexually active girls in whom transvaginal US would be contraindicated. MRI is generally a second-line examination and is preferred over CT because it does not involve the use of ionizing radiation. MRI might be underutilized in this population, particularly in differentiating surgical from nonsurgical conditions. This article reviews the relevant anatomy and discusses imaging of acquired conditions that involve the pediatric female genital tract, illustrating associated pathology with case examples.

Useful signs for the assessment of vascular rings on cross-sectional imaging.

Vascular rings can be challenging to diagnose because they can contain atretic portions not detectable with current imaging modalities. In these cases, where the compressed airway and esophagus are not encircled by patent, opacified vessels, there are useful secondary signs that should be considered and should raise suspicion for the presence of a vascular ring. These signs include a double aortic arch, the four-vessel sign, the distorted subclavian artery sign, a diverticulum of Kommerell, a ductal diverticulum contralateral to the aortic arch, and a descending aorta contralateral to the arch or circumflex aorta. If none of these findings is present, a ring can be excluded with confidence.

Magnetic Resonance Imaging of Developmental Anomalies of the Uterus and the Vagina in Pediatric Patients.

Developmental anomalies of the uterus and the vagina are associated with infertility and miscarriage and are most commonly detected in the postpubertal age-group. These conditions may also present in younger patients as a mass or pain owing to obstruction of the uterus or the vagina. Associated urinary tract anomalies are common, as well. Accurate diagnosis and thorough description of these anomalies is essential for appropriate management; however, evaluation may be difficult in an immature reproductive tract. Magnetic resonance imaging technique pertinent to imaging of the pediatric female reproductive tract is presented and illustrated along with the findings associated with various anomalies.

Congenital urethral polyps in the pediatric population.

Congenital urethral polyps are a rare entity. Most commonly, they present as benign posterior urethral growths in the pediatric male patient. However, reports of urethral polyps in female patients or even those with an anterior urethral location can also be found in the literature. Patients can present with a spectrum of symptoms including dysuria, hematuria, and obstructive type urinary complaints. Diagnosis in these cases includes a combination of medical imaging (e.g. ultrasound, fluoroscopic, CT or MRI), direct endoscopic visualization, and final surgical pathology. Treatment involves surgical removal either via an endoscopic or open approach.

Protocol for MRI of the hips after spica cast placement.

BACKGROUND: In reduction of hip displacement in developmental dysplasia, concentric placement of the femoral head within the acetabulum is key. Magnetic resonance imaging (MRI) is an effective modality to assess the adequacy of the reduction, but sedation may be required due to the length of the examination. MRI is also more expensive than other imaging modalities. Our goal was to provide an MRI protocol that does not require sedation and can be performed in <15 minutes. METHODS: We retrospectively reviewed 34 consecutive MRI studies performed without sedation after spica cast placement in 24 developmental hip dysplasia patients. The MRI examinations were performed with a variety of techniques. Sequences used were evaluated for contrast, resolution, and motion artifact. RESULTS: Ninety-seven percent of studies were diagnostic, although 18% of examinations had significant motion artifact. Seven sequences were analyzed. T2-weighted fast spin echo sequences had the best overall scores and were performed in <3 minutes. T1 and fat-suppressed T2-weighted fast spin echo sequences did not score as well, and also required <3 minutes. Single-shot fast spin echo sequences scored poorly due to decreased contrast and resolution, despite shorter acquisition times of 20 to 40 seconds. Three-dimensional (3D) gradient recovery imaging scored poorly due to lower contrast and increased motion due to longer acquisition times of approximately 4 minutes. Both coronally and axially oriented sequences satisfactorily assessed femoral head position within the acetabulum. CONCLUSIONS: MRI is a useful tool in evaluating the hips without radiation exposure and without sedation in infants and toddlers after spica cast placement. Both axial and coronal T2 fast spin echo MRI sequences provided excellent anatomic definition and required ≤3 minutes per sequence. Orthopaedic surgeons can request these 2 sequences for accurate assessment of concentric reduction with a potential study time of 15 minutes, obviating the need for sedation. LEVEL OF EVIDENCE: Level II.