The ductus arteriosus: a review of embryology to intervention.

This article reviews the physiology of the ductus arteriosus, the pathophysiology of the patent ductus arteriosus (PDA), and the role advanced imaging such as computed tomography (CT) and magnetic resonance imaging (MRI) can play in guiding diagnosis and percutaneous or surgical intervention. A PDA can have variable clinical and radiologic presentations and can be important to characterize in patients with vascular rings, aortic maldevelopment and congenital heart disease. An understanding of the PDA and the application of CT and MRI can allow the radiologist to provide key information to physicians who plan to close a PDA or maintain PDA patency in the setting of ductal-dependent congenital heart disease.

Medial meniscal posterior horn tears and ramp lesions in pediatric patients: lessons learned.

Meniscal injuries are increasingly reported in pediatric patients due to early sports participation and are commonly encountered during anterior cruciate ligament reconstruction. Preoperative identification of meniscal tears is crucial, particularly when involving the posteromedial meniscocapsular junction (ramp lesion). MRI plays an important role in detecting this particular type of meniscal injury. Consequently, pediatric radiologists should be aware of particular MRI findings related to ramp lesions including the presence of a medial meniscal tear, peripheral meniscal irregularity, meniscocapsular junctional fluid-like signal intensity, and capsular ligament tears. Thus, we illustrate the lessons we have learned from our institutional multidisciplinary arthroscopic-MR correlation conference for retrospectively identified posterior horn medial meniscal tears and ramp lesions.

An infant with LUMBAR syndrome complicated by severe perineal ulceration managed with diverting colostomy.

Infantile hemangiomas are the most common childhood vascular lesions. LUMBAR syndrome (lower body hemangioma, urogenital abnormalities/ulceration, myelopathy, bony deformities, anorectal malformations/arterial anomalies, and rectal anomalies) warrants special treatment considerations. Here we describe a case of an infant with LUMBAR syndrome who presented with severe perineal ulceration refractory to standard medical therapy and was managed with a temporary diverting sigmoid colostomy. This case demonstrates that adjunctive surgical management can be considered in infants with aggressive perineal wounds refractory to standard medical therapy.

Cardiac Computed Tomographic Angiography Evaluation of Right Ventricle-Pulmonary Artery Conduits with Surgical Correlation.

Right ventricle-pulmonary artery (RV-PA) conduits are used in the treatment of certain congenital heart disease (CHD). RV-PA conduit complications might develop over time and require intervention. To evaluate how well cardiac computed tomographic angiography (CCTA) performs compared to transthoracic echocardiography (TTE) in evaluating RV-PA conduit complications by using surgical findings as the reference standard. A retrospective chart review of all patients over a 5-year period who underwent CCTA for RV-PA conduit evaluation was performed. Patient demographics and clinical data were recorded. Preoperative CCTA and TTE findings were compared to the operative findings for concordance or discordance. Forty-one patients were included, 51% females. The complications were conduit stenosis (28.68%), infection (7.17%) and aneurysm/pseudoaneurysm (6.15%). TTE and CCTA were consistently able to visualize focal conduit stenosis (96%). The greatest discrepancy between TTE and CCTA was in evaluating for aneurysm/pseudoaneurysm, where TTE detected only 2/6 (33%) compared to CCTA which detected 6/6 (100%) of the cases. However, TTE was slightly better at detecting conduit infection (3/7, 43%) compared to CCTA (2/7, 29%). Note that 5 out of 7 patients with endocarditis had bovine jugular graft. CCTA and TTE provide similar diagnostic accuracy evaluating certain types of RV-PA conduit complications. However, certain complications were only visualized on CCTA or TTE making both modalities complementary to each other during diagnostic evaluation.

Working from home during the COVID-19 pandemic: surveys of the Society for Pediatric Radiology and the Society of Chiefs of Radiology at Children's Hospitals.

BACKGROUND: Due to the COVID-19 pandemic, some pediatric radiologists have shifted to working from home; the long-term ramifications for pediatric radiologists and departments have not yet been defined. OBJECTIVE: To characterize experiences of working from home associated with the COVID-19 pandemic and guide expectations after the pandemic is controlled, via separate surveys of Society for Pediatric Radiology (SPR) and Society of Chiefs of Radiology at Children's Hospitals (SCORCH) members. MATERIALS AND METHODS: Two separate surveys were conducted. In the first, SPR members were surveyed Jan. 11 through Feb. 8, 2021. The response rate was 17.0% (255 of 1,501). Survey questions included demographics, information on the ability to work from home and subjective experiences ranked on a scale of 0 to 10. The survey enabled segregation and comparison of responses between those with and without home PACS. In the second survey, SCORCH members were surveyed Dec. 8, 2020, through Jan. 8, 2021. The response rate was 51.5% (51/99). Survey questions included the logistics of working from home, technical specifications and the expectations on clinical duties performed from home. The Wilcoxon rank test was used to determine statistical significance of compared variables between respondents with and without home PACS in SPR members, and expectations between SPR and SCORCH members. Descriptive statistics summarized demographic questions and free text responses. RESULTS: The majority of member respondents (81.2%, 207/255) had a home PACS and most departments provided home PACS to faculty (94.1%, 48/51). Overall, radiologists who could work from home were satisfied with their ability to work from home (mean rating: 8.3/10) and were significantly more satisfied than predicted by those without home PACS (5.9/10, P<0.0001). Respondents overwhelmingly indicated they were less able to teach trainees (mean rating: 2.7/10) and had decreased emotional engagement (mean rating: 4.4/10), but had improved research productivity and cognitive ability for research when working from home (mean rating for both: 5.3/10). Regarding the expectations of the ability to work from home after no longer needing to address the pandemic, department chairs generally favored fewer rotations from home, with 97.9% (47/48) indicating working from home should be 60% or fewer assignments, compared with 84.1% (164/195) of individual radiologists (P=0.071). CONCLUSIONS: Due to the COVID-19 pandemic, there has been a shift to working from home using PACS. Results of these SPR and SCORCH member surveys can help inform future decisions regarding pediatric radiologists working from home once the pandemic has been controlled.

Accuracy of computed tomography angiography and structured reporting of high-risk morphology in anomalous aortic origin of coronary artery: comparison with surgery.

BACKGROUND: Morphological features including interarterial course, intramural course, high ostial location and slit-like ostium are presumed risk factors for sudden cardiac death in children with anomalous aortic origin of the coronary artery (AAOCA). To facilitate clinical risk stratification, the diagnostic accuracy of CT angiography for individual risk factors in the setting of AAOCA must be established. OBJECTIVE: We assessed diagnostic accuracy of standardized CT angiography interpretation for morphological characteristics that might determine risk in children with AAOCA by comparing them to surgical findings. MATERIALS AND METHODS: We created a standardized protocol for CT angiography of AAOCA and retrospectively evaluated diagnostic performance in 25 consecutive surgical patients. Relevant morphological variables in AAOCA were assessed by three independent blinded readers, with surgery as the reference standard. We used Cohen kappa coefficients and accuracies to assess agreement between readers and surgical findings, and we calculated intraclass correlation coefficients to compare length of the intramural course. RESULTS: CT angiography correctly identified AAOCA in all patients. For the three readers, accuracies for detecting ostial stenosis were 84%, 94% and 96%; for high ostial origin, accuracies were 76%, 78% 82%; for intramurality using the peri-coronary fat sign, accuracies were 98%, 96% and 92%; and for intramurality using oval shape of coronary artery, accuracies were 98%, 94% and 92%. The intraclass correlation coefficients (ICCs) for predicting intramural length among the three readers were 0.67, 0.75 and 0.81 using peri-coronary fat, and 0.69, 0.50 and 0.81 using oval shape, respectively. CONCLUSION: CT angiography reliably identified AAOCA in all children and detected the presence of intramurality with high accuracy.

Pediatric Bassett's ligament: pathology or normal anatomy?

BACKGROUND: Bassett's ligament is an accessory fascicle of the anterior inferior tibiofibular ligament. The prevalence, normal thickness and clinical implications of a thickened ligament have not been described in the pediatric radiology literature. OBJECTIVE: The purpose of this study was to determine the prevalence and thickness of Bassett's ligament in pediatric patients with magnetic resonance imaging (MRI) findings of lateral talar osteochondral lesions, medial talar osteochondral lesions and posterior ankle impingement, to compare these measurements with normal MRIs, and to compare the reproducibility of these measurements. MATERIALS AND METHODS: This is a retrospective study of pediatric ankle MRIs with four cohorts containing 21 patients each. All MRIs were retrospectively reviewed by a pediatric musculoskeletal radiologist and a pediatric radiology fellow. The prevalence of Bassett's ligament and its axial thickness were obtained for each cohort with repeat measurements for intra-observer and interobserver variability. Average thickness and standard deviation of Bassett's ligament were calculated. RESULTS: The prevalence of Bassett's ligament and its thickness in each cohort were (mean±standard deviation): lateral osteochondral lesions, 71% (15/21), 1.9±0.5 mm; medial osteochondral lesions, 52% (11/21), 1.4±0.2 mm; posterior impingement, 52% (11/21), 1.3±0.2 mm; and normal ankle examinations, 71% (15/21), 1.5±0.4 mm. The thickness of Bassett's ligament was increased in the lateral talar osteochondral lesion group when compared to normal (P=0.02), while thickness in the medial osteochondral lesion and posterior impingement groups was not significant when compared to normal. The repeat measurements showed no significant difference in intra-observer and interobserver variability. CONCLUSION: Bassett's ligament is a normal structure in children. Thickening of Bassett's ligament is seen with lateral osteochondral lesions and may be an indirect sign of anterolateral tibiotalar capsule injury.

Role of gated cardiac computed tomographic angiography in the evaluation of postsurgical complications after stage I Norwood procedure and its implications on management: a comparative study with two-dimensional echocardiography.

BACKGROUND: The Norwood procedure is the first part of a three-stage surgical palliation for patients with functionally single ventricle anatomy. Complications after the stage I operation are not uncommon. Transthoracic echocardiography (TTE) is traditionally the mainstay for evaluation. OBJECTIVE: The purpose of our study is to compare gated cardiac computed tomographic angiography (CCTA) with TTE when evaluating for postoperative complications after stage I Norwood procedure and to describe management implications. MATERIALS AND METHODS: A retrospective chart review of all patients over a 4-year period who underwent nonelective urgent CCTA for suspected complications related to stage I Norwood procedure was performed. Elective CCTA studies before stage II palliation were excluded. Patient demographics, CCTA and TTE findings, as well as interventions performed, were recorded. RESULTS: Thirty-four patients were included. The mean age at CCTA was 63 days (range: 4-210 days). All patients had a recent TTE with a mean time interval between TTE and CCTA of 2 days. CCTA detected 56 abnormalities in 30 patients, with 23 directly related to postsurgical complications, including shunt-related complications (10/23, 43%), Damus-Kaye-Stansel anastomotic narrowing (2/23, 9%) and neo-aortic arch/branch vessel abnormalities (11/23, 48%). These complications were managed as follows: surgery (9, 39%), catheter-based intervention (7, 30%), medical (4, 17%) and no change in management (3, 13%). TTE did not detect 8/23 (35%) findings found on CCTA, of which 75% were either managed with surgery (4/8, 50%) or catheter-based intervention (2/8, 25%). CONCLUSION: CCTA plays an important role in detecting surgical complications after stage I Norwood procedure and demonstrates additional findings that have direct management implications.

Diagnostic sensitivity and specificity of CT angiography for renal artery stenosis in children.

BACKGROUND: Children with suspected renal artery stenosis (RAS) are screened with renal Doppler ultrasonography or computed tomography (CT) angiography/magnetic resonance (MR) angiography depending on institutional preference. CT angiography produces images with superior resolution, allowing higher quality multiplanar two-dimensional reformats and three-dimensional reconstructions. However, there is a paucity of data in the literature regarding the utility and diagnostic performance of renal CT angiography in pediatric RAS. OBJECTIVE: The objective of this study is to retrospectively review our experience with renal CT angiography in the diagnosis of pediatric RAS relative to digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: All patients 0-18 years of age who underwent CT angiography for evaluation of RAS as a cause of hypertension between January 2012 and May 2019 were identified for the study. A total of 131 patients were identified, 23 of whom had DSA correlation. RESULTS: Twenty-three patients (17 boys, 6 girls) with a mean age of 6 years 3 months (range: 3 months to 14 years 7 months) were included in this study. Of the 59 renal arteries studied by DSA, 22 were abnormal on CT angiography and 20 were abnormal on DSA. Of the 59 renal arteries, CT angiography was true positive in 18 and true negative in 35. The sensitivity and specificity of CT angiography for RAS diagnosis were 90.0% and 89.7%, respectively. CT angiography identified all cases of main RAS. CONCLUSION: Renal CT angiography has a high sensitivity and specificity for pediatric RAS diagnosis in patients referred for DSA.

Percutaneous ultrasound-guided ganglion fenestration in children: initial results.

OBJECTIVE: To evaluate our pediatric experience with percutaneous ultrasound-guided fenestration of ganglia (PUGG). MATERIALS AND METHODS: Retrospective study of pediatric patients who underwent PUGG from June 2016 to October 2018 at a free-standing tertiary referral academic children's hospital with a minimum of 6 months follow-up. Electronic medical records, picture archiving system, and post-procedural calls were utilized for patient demographics, lesion characteristics, procedure details, and recurrence. The procedure itself consisted of assessment by Child Life, application of topical anesthetic cream, sterile preparation and draping, and intra-procedural ultrasound guidance for local anesthetic instillation, ganglion aspiration, fenestration, and intra-remnant steroid instillation. Post-procedure care included an ice pack, compression dressing for 48 h, and 4 weeks of brace wear and activity restriction. RESULTS: Forty-five patients met the inclusion criteria, ages 3-18 years, mean 13.5 years, and female to male ratio of 2:1. Ganglion locations consisted of 80% (36/45) in the wrist and 20% (9/45) in other locations (elbow, ankle, and foot). Ninety-eight percent (44/45) of procedures were performed non-sedated, including 20% (9/44) between ages 7 and 11 years. 28.9% (13/45) of ganglia recurred, the earliest at 3 weeks, the latest at 10 months, and an average of 3 months' time. No complication occurred and no patients required post-procedural narcotics or Emergency Department visitation for pain control. CONCLUSION: Percutaneous ultrasound-guided fenestration of ganglia (PUGG) is a safe, minimally invasive alternative to surgical excision in the pediatric population, which can be performed without sedation and does not leave a scar.

Arcuate sign-fibular head avulsion fracture and associated injuries in the pediatric and adolescent population.

PURPOSE: To describe the first "arcuate sign" case series in the pediatric population, radiologic features of the associated injuries, management, and how they compare with the adult population. METHODS: Retrospective study included patients under 18 years of age with a classic "arcuate sign" on radiographs. Data collected included patient demographics, mechanism of injury, and management. Radiographs and advanced imaging (MRI, CT) were reviewed by two musculoskeletal radiologists in a blinded fashion and findings recorded. RESULTS: Seven patients (4 males, 3 females) with mean age 15 years (range 14-17 years) were included in the study. All 7 injuries were related to sports, 5/7 (71%) being non-contact injuries. Five patients had MRI done-1 LCL injury, MPFL sprain, and MCL sprain were reported; 3 popliteofibular ligament and popliteus sprains were seen; and 3 bone contusions were present on imaging. None of the patients had meniscus or cruciate ligament tears. One patient had an additional fracture of the lateral tibial plateau at the ilio-tibial band attachment and an associated peroneal nerve injury. Five out of seven (71.4%) were treated non-operatively and were able to return back to activity at a mean of 7.2 weeks from injury. Two out of seven (28.6%) needed operative intervention for the fracture but not arthroscopic repair. CONCLUSION: Pediatric patients with a radiographic arcuate sign tend not to have ACL, PCL, or meniscal injuries, and treatment is predominantly non-operative in contrast to literature reported in adults.

Delayed diagnosis of posterior ankle impingement in pediatric and adolescent patients: does radiology play a role?

BACKGROUND: Posterior ankle impingement syndrome (PAIS) results from the pinching of anatomical structures in the posterior part of the ankle. OBJECTIVE: To identify the possible role of imaging in the delayed diagnosis of PAIS and identify key findings on imaging to suggest PAIS in pediatric and adolescent patients. MATERIALS AND METHODS: Data were collected prospectively in patients younger than 18 years of age who underwent arthroscopy after being diagnosed with PAIS. Imaging was reviewed retrospectively by two radiologists, compared with findings in literature and an age-matched control group, and correlated with arthroscopic findings. Pre- and postsurgical Visual Analogue Scale (VAS) pain and American Orthopedic Foot Ankle Society (AOFAS) ankle-hindfoot scores were noted. RESULTS: Thirty-eight patients (20 females, 18 males), 51 ankles, with an average age of 12.9 years had an average 18-month delay in diagnosis. Twenty-seven of the 38 (73%) patients had previously seen multiple medical providers and were given multiple misdiagnoses. Radiographs were reported normal in 34/47 (72%) ankles. Thirty patients had magnetic resonance imaging (MRI) and findings included the presence of an os trigonum/Stieda process (94%) with associated osseous edema (69%), flexor hallucis longus (FHL) tenosynovitis (16%), and edema in Kager's fat pad (63%). Although individual findings were noted, the impression in the MRI reports in 16/32 (50%) did not mention PAIS as the likely diagnosis. There was a significant difference in the MRI findings of ankle impingement in the patient population when compared to the control group. Surgery was indicated after conservative treatment failed. All 51 ankles had a PAIS diagnosis confirmed during arthroscopy. At an average follow-up of 10.2 months, there was improvement of VAS pain (7.0 to 1.1) and AOFAS ankle-hindfoot scores (65.1 to 93.5). CONCLUSION: PAIS as a diagnosis is commonly delayed clinically in young patients with radiologic misinterpretation being a contributing factor. Increased awareness about this condition is needed among radiologists and physicians treating young athletes.

Correlation of ductus arteriosus length and morphology between computed tomographic angiography and catheter angiography and their relation to ductal stent length.

BACKGROUND: Patent ductus arteriosus (PDA) stent placement in infants with ductal-dependent pulmonary blood flow is being increasingly used in clinical practice. OBJECTIVE: To correlate computed tomographic (CT) angiography morphology and length of the PDA with catheter angiography and its relation to eventual PDA stent length. MATERIALS AND METHODS: We retrospectively identified all pediatric patients who underwent PDA stenting at our institute from 2004 to 2018. We included children who had CT angiography prior to stenting. PDA length was measured by a radiologist blinded to the catheter angiography data, using Syngo-via post-processing software (Siemens, Erlangen, Germany). Vessel centerline technique was used. We measured the actual length of the duct as well as straight length between aortic and pulmonary ends. PDA morphology tortuosity index was classified as straight (Type I), mildly tortuous with 1 turn (Type II) and tortuous with >1 turn (Type III), and the PDA origin was noted. The PDA was also measured and morphology classified on catheter angiography by an interventional cardiologist blinded to the CT angiography findings. We compared the CT angiography and catheter angiography lengths, straight lengths and stent length using scatter plots and intraclass correlation coefficient (ICC). RESULTS: A total of 83 children who had PDA stenting were identified, of whom 17 had prior CT angiography. Fifteen of these were neonates. There was agreement between CT angiography and catheter angiography regarding the PDA morphology tortuosity index in 94% of cases and PDA origin in 100% of cases. There was moderate agreement between CT angiography and catheter angiography actual and straight PDA lengths, with ICC coefficients of 0.65 and 0.68, respectively. There was moderate agreement between CT angiography actual length, CT angiography straight length, catheter angiography actual length and eventual stented PDA length, with ICCs of 0.57, 0.67 and 0.73, respectively. There was poor agreement between catheter angiography straight length and eventual stented PDA length, with an ICC of 0.39. CONCLUSION: PDA length and morphology description on CT angiography correlates well with catheter angiography and can be a reliable guide for the interventional cardiologist in decision-making regarding appropriate choice of PDA stent length.

Value of emergent pediatric cardiac computed tomographic angiography service: initial experience at a large children's hospital.

BACKGROUND: Demand for pediatric cardiac computed tomography (CT) angiography is increasing due to recent advances that reduce the need for sedation and radiation exposure while enhancing diagnostic accuracy. This has resulted in the increasing use of cardiac CT angiography emergently during weekends and after hours. The unexpected demand for these services can be challenging, as most hospitals are not staffed to provide 24/7 pediatric cardiovascular imaging. OBJECTIVE: To describe a large single-center experience of providing emergent cardiac CT angiography services in children. MATERIALS AND METHODS: We identified all patients who underwent after--hours weekday and weekend emergent cardiac CT angiography between January 2017 and August 2018. Cardiac CT angiography in the settings of congenital heart disease and coronary imaging were included. Data collected included day and time of cardiac CT angiography, patient age, referral unit, indication, surgical history, need for sedation, need for surgery, intervention and/or change in medical management based on the cardiac CT angiography. RESULTS: Forty-seven studies were identified, 26 (55%) of which were performed on a weekend or holiday and 21 (45%) after 5 p.m. on a weekday. Based on cardiac CT angiography findings, 20 (43%) patients underwent either surgery or an interventional procedure, and 9 (19%) had a change in medical management. The time between cardiac CT angiography and the related surgery/intervention ranged from 0 to 29 days with a median of 3.5 days. CONCLUSION: Emergent pediatric cardiac CT angiography is a valuable service. Larger multi-institutional studies with standardized referral and utilization patterns are needed to determine if outcomes are affected by this service, which in turn will influence hospital staffing patterns for emergent imaging.

E-cigarette or vaping product use-associated lung injury in the pediatric population: imaging features at presentation and short-term follow-up.

BACKGROUND: Cases of e-cigarette or vaping product use-associated lung injury (EVALI) have rapidly reached epidemic proportions, yet there remain limited reports within the literature on the associated imaging findings. OBJECTIVE: We describe the most common imaging findings observed on chest computed tomography (CT) and chest radiograph (CXR) at presentation and at short-term follow-up at our major pediatric hospital. MATERIALS AND METHODS: A retrospective review of the electronic medical records was performed on all patients with suspected EVALI who were treated at a major pediatric hospital and 11 patients were included for analysis. Two board-certified pediatric radiologists then categorized the CXRs as either normal or abnormal, and further performed a systematic review of the chest CTs for imaging findings in the lungs, pleura and mediastinum. Interrater discordance was reconciled by consensus review. RESULTS: The 11 patients (9 males:2 females) ranged in age from 14 to 18 years. Gastrointestinal and constitutional symptoms were present in all patients, whereas shortness of breath and cough were reported in 5/11 and 6/11 patients, respectively. The CXR was abnormal in 10/11 patients, whereas all chest CTs were abnormal. The most common CT findings included consolidation, ground-glass opacities, interlobular septal thickening, lymphadenopathy and crazy-paving pattern. Almost all patients demonstrated subpleural sparing, and less than half also demonstrated peribronchovascular sparing. There was complete or near-complete resolution of imaging abnormalities in 5/6 patients with a median follow-up duration of 114 days. CONCLUSION: Pulmonary opacities with subpleural and peribronchovascular sparing was a commonly observed pattern of EVALI in the pediatric population at this institution. A CXR may not be sufficiently sensitive in diagnosing EVALI, and radiologists and clinicians should exercise caution when excluding EVALI based on the lack of a pulmonary opacity. Caution should also be exercised when excluding EVALI solely based on the lack of respiratory symptoms. Despite extensive pulmonary involvement at presentation, findings may resolve on short-term follow-up imaging.

A novel approach using volumetric dynamic airway computed tomography to determine positive end-expiratory pressure (PEEP) settings to maintain airway patency in ventilated infants with bronchopulmonary dysplasia.

BACKGROUND: Positive end-expiratory pressure (PEEP) is a key mechanical ventilator setting in infants with bronchopulmonary dysplasia (BPD). Excessive PEEP can result in insufficient carbon dioxide elimination and lung damage, while insufficient PEEP can result in impaired gas exchange secondary to airway and alveolar collapse. Determining PEEP settings based on clinical parameters alone is challenging and variable. OBJECTIVE: The purpose of this study was to describe our experience using dynamic airway CT to determine the lowest PEEP setting sufficient to maintain expiratory central airway patency of at least 50% of the inspiratory cross-sectional area in children with BPD requiring long-term ventilator support. MATERIALS AND METHODS: We retrospectively identified all infants with BPD who underwent volumetric CT with a dynamic airway protocol for PEEP optimization from December 2014 through April 2019. Sixteen infants with BPD underwent 17 CT exams. Each CT exam consisted of acquisitions spanning the trachea and mainstem bronchi. We measured cross-sectional area of the trachea and mainstem bronchi and qualitatively assessed the amount of atelectasis. We documented changes in management as a result of the CT exam. RESULTS: The average effective dose was 0.1-0.8 mSv/scan. Of 17 CT exams, PEEP was increased in 9, decreased in 3 and unchanged after 5 exams. CONCLUSION: Dynamic airway CT shows promise to assist the clinician in determining PEEP settings to maintain airway patency in infants with BPD requiring long-term ventilator support. Further evaluation of the impact of this maneuver on gas exchange, cardiac output and other physiological measures is needed.

Utility of immediate postoperative hip MRI in developmental hip dysplasia: closed vs. open reduction.

BACKGROUND: Magnetic resonance imaging (MRI) of the hips is being increasingly used to confirm hip reduction after surgery and spica cast placement for developmental dysplasia of the hip (DDH). OBJECTIVE: To review a single institutional experience with post-spica MRI in children undergoing closed or open hip reduction and describe the utility of MRI in directing the need for re-intervention. MATERIALS AND METHODS: Seventy-four patients (52 female, 22 male) who underwent post-spica hip MRI over a 6-year period were retrospectively reviewed. One hundred and seven hips were included. Data reviewed included age at intervention, gender, type of intervention performed, MRI findings, the need for re-intervention and the interval between interventions. Gender was compared between the closed and open reduction groups via the Fisher exact test. Age at the first procedure was compared via the Wilcoxon rank test. Rates of re-intervention after closed and open reduction were calculated and the reasons for re-intervention were reviewed. RESULTS: The mean age at the time of the first intervention was 16.4 months (range: 4 to 63 months). Mean age for the closed reduction group was 10.5 months (range: 4-24 months) and for the open reduction group was 23.7 months (range: 5-63 months), which was significant (P-value <0.0001). Of the 52 hips that underwent closed reduction, 16 (31%) needed re-intervention. Of the 55 hips that underwent open reduction, MRI was useful in deciding re-intervention in only 1 (2%). This patient had prior multiple failed closed and open reductions at an outside institute. CONCLUSION: Post intervention hip spica MRI is useful in determining the need for re-intervention after closed hip reduction, but its role after open reduction is questionable.

Modified Friedman technique: a new proposed method of measuring glenoid version in the setting of glenohumeral dysplasia.

BACKGROUND: Glenoid version angles are measured to objectively follow changes related to glenohumeral dysplasia in the setting of brachial plexus birth palsy. Measuring glenoid version on cross-sectional imaging was initially described by Friedman et al. in 1992. Recent literature for non-dysplastic shoulders advocates time-consuming reconstructions and reformations for an accurate assessment of glenoid version. OBJECTIVE: To compare Friedman's original method for measuring glenoid version to a novel technique we developed ("modified Friedman") with the reference standard of true axial reformations. MATERIALS AND METHODS: With institutional review board approval, we retrospectively examined 30 normal and dysplastic shoulders obtained from magnetic resonance imaging examinations of 30 patients with an established diagnosis of brachial plexus birth palsy between January 2012 and September 2017. Four pediatric radiologists performed glenoid version measurements using Friedman's method, the modified Friedman method and a previously described true axial reformation method. The modified Friedman technique better accounts for scapular positioning by selecting a reference point related to the acromion-scapular body interface. Inter-rater reliability and inter-method agreement were assessed using intraclass correlation, paired t-tests and mixed linear model analysis. Equivalence tests between methods were performed per reader. RESULTS: Glenoid version measurements were significantly different when comparing Friedman's method to true axial reformations in normal (-10.8±5.7° [mean±standard deviation] vs. -8.8±5.3°; P≤0.001) and dysplastic shoulders (-34.6±17.7° vs. -28.1±17.5°; P≤0.001). Glenoid version measurements were not significantly different when comparing the modified Friedman's method to true axial reformations in normal (-6.3±5.8° vs. -8.8±5.3°; P=0.06) and dysplastic shoulders (-29.0±18.3° vs. -28.1±17.5°; P=0.06). Friedman's method was not equivalent to true axial reformations for measurements in dysplastic shoulders for all readers (P=0.68, 0.81, 0.86, 0.99); the modified Friedman method was equivalent to of true axial reformations for measurements in dysplastic shoulders for 3 of 4 readers (P≤0.001, P≤0.001, P≤0.001, P=0.10). CONCLUSION: In glenohumeral dysplasia, the modified Friedman method and post-processed true axial reformations provide statistically similar and reproducible values. We propose that our modified Friedman technique can be performed in lieu of post-processed true axial reformations to generate glenoid version measurements.

Searching for certainty: findings predictive of appendicitis in equivocal ultrasound exams.

BACKGROUND: Ultrasound (US) is the preferred imaging modality for evaluating suspected pediatric appendicitis. However, borderline appendiceal enlargement or questionable inflammatory changes can confound interpretation and lead to equivocal exams. OBJECTIVE: The purpose of this study was to determine which findings on equivocal US exams are most predictive of appendicitis. MATERIALS AND METHODS: All US exams performed for suspected pediatric appendicitis from July 1, 2013, through July 9, 2014, were initially interpreted using a risk-stratified scoring system. Two blinded pediatric radiologists independently reviewed US exams designated as equivocal and recorded the following findings: increased wall thickness, loss of mural stratification, peri-appendiceal fat inflammation, peri-appendiceal fluid, appendicolith and maximum appendiceal diameter. A third pediatric radiologist resolved discrepancies. US features were correlated with the final diagnosis via multivariate analysis. RESULTS: During the study period, 162/3,750 (4.3%) children had US exams initially interpreted as equivocal (mean age 9.8 +/- 3.8 years). Five outpatients were lost to follow-up. Forty-eight of the remaining 157 (30.6%) children had an operative diagnosis of appendicitis. Findings significantly associated with appendicitis were loss of mural stratification (odds ratio [OR] = 6.7, P=0.035), peri-appendiceal fat inflammation (OR = 10.0, P<0.0001) and appendicolith (OR = 15.8, P=0.025). While appendiceal diameter tended to be larger in patients with appendicitis, the difference was not statistically significant. CONCLUSION: Loss of mural stratification, peri-appendiceal fat inflammation and an appendicolith are significant predictors of appendicitis in children with otherwise equivocal US exams. While maximum appendiceal diameter is not statistically associated with appendicitis in our study, mean appendiceal diameter of 6.7 mm in those without appendicitis suggests that the customary upper normal limit of 6 mm is too sensitive.