Traumatic abdominal wall hernias in the pediatric population: a 13-year institutional review.

BACKGROUND: Pediatric traumatic abdominal wall hernias are rare but potentially devastating injuries. Although classically considered to be caused by handlebar injuries from bicycle accidents, our anecdotal experience suggests pediatric traumatic abdominal wall hernias are far more likely to occur following road traffic accidents and have a high association with other significant intra-abdominal injuries. OBJECTIVE: The purpose of this study was to determine the frequency, mechanisms of injury, and associated injuries of traumatic abdominal wall hernias in the pediatric population. MATERIALS AND METHODS: This is a retrospective observational cohort study from two large urban level 1 trauma centers. Institutional trauma registries were queried from January 1, 2008, to December 31, 2020, for patients under 18 years of age diagnosed with traumatic abdominal wall hernias, excluding those without initial abdominopelvic CT imaging. Finalized CT reports and images were reviewed to confirm the presence of a traumatic abdominal wall hernia and document any associated secondary injuries. The medical record was reviewed to extract pertinent physical findings, interventions performed, and outcomes. Injury Severity Score (ISS) for each patient was calculated by the trauma registrar. RESULTS: A total of 19 patients with TAWH met inclusion criteria, with an overall frequency of 0.095% and a mean age of 10.6 years (range 3-17). Eleven patients were male (57.9%) with a mean ISS of 18.6 (range 1-48, including 63.2% with ISS > 15). The most common mechanism of injury was motor vehicle collision (N = 11, 57.9%) followed by bicycle accident (N = 3, 15.8%). A total of 17 (89.5%) had associated injuries, including 11 (57.9%) with intestinal injuries, 5 (26.3%) with pelvic fractures, 4 (21.1%) with femur fractures, 3 (15.8%) with splenic injuries, 3 (15.8%) with kidney injuries, and 3 (15.8%) with Chance fractures of the lumbar spine. All patients required surgery for the traumatic abdominal wall hernias and associated injuries. CONCLUSION: Pediatric traumatic abdominal wall hernias are more likely to be seen following motor vehicle collisions, with a majority (89.5%) having associated injuries, most frequently to the bowel (57.9%). Handlebar injuries were seen in a minority of patients (15.8%) and were less likely to be associated with additional injuries. CLINICAL IMPACT: Pediatric patients with a traumatic abdominal wall hernia on admission CT should be thoroughly evaluated for bowel injuries, especially in the setting of a motor vehicle collision.

Urinary excretion of low-osmolar contrast media during small-bowel follow-through studies in infants is not definitive evidence of bowel perforation.

BACKGROUND: Presence of contrast agent in the urinary system in infants after small-bowel follow-through study with low-osmolar contrast media has been described as a sign of bowel perforation. OBJECTIVE: To evaluate how often the presence of contrast agent in the bladder after small-bowel follow-through is a reliable sign of bowel perforation or necrosis. MATERIALS AND METHODS: From the radiology information system, we retrieved imaging reports of infants evaluated with small-bowel follow-through and findings of contrast agent in the bladder. We retrieved demographic and clinical information from the medical records. Presence of bladder contrast medium was considered true-positive evidence of bowel perforation or necrosis if confirmed by pneumoperitoneum, extraluminal contrast agent, surgery or pathology within 3 days of the small-bowel follow-through. False-positives for bowel perforation or necrosis were based on surgical findings or clinical follow-up. RESULTS: Of the 207 infants who had small-bowel follow-through, 18 infants (12 boys; mean age 50 days, range 14 days to 8.5 months) had contrast medium in the bladder after the small-bowel follow-through. Fifteen of the 18 (83.3%) had a history of prematurity and 11 had prior abdominal surgery. Four of the 18 (22.2%) had bowel perforation or necrosis at surgery or pathology performed more than 3 days after the small-bowel follow-through and were considered indeterminate and excluded. Eight of the remaining 14 infants (57.1%) had bowel perforation or necrosis based on surgical evidence of perforation or pathology confirmation of necrosis (n=6), pneumoperitoneum (n=1) or contrast agent leakage from enterocutaneous fistula (n=1). Six of the 14 (42.9%) were false-positives, without evidence of bowel perforation or necrosis based on clinical follow-up (n=4) or surgery (n=2). CONCLUSION: Demonstration of urinary contrast agent post small-bowel follow-through with low-osmolar contrast medium in newborns/infants with complex medical problems is not a definitive indication of bowel perforation or necrosis. More than one-third of our patients with contrast medium in the bladder did not have bowel perforation or necrosis.

Chest CT in the evaluation of child abuse - When is it useful?

BACKGROUND: Indications for chest CT in evaluation of child abuse are unknown. OBJECTIVE: Determine which groups of children can best benefit from chest CT. PARTICIPANTS AND SETTING: 10-year (1/2010 to 12/2019) retrospective study of children <3 years who had chest CT within 3 days of the initial skeletal survey. METHODS: Demographic and clinical information were obtained from medical records. Two pediatric radiologists reviewed, independently and blinded to clinical information, anonymized rib X-rays (initial and follow up when available) and chest CT. Disagreements were resolved by a third pediatric radiologist. Agreement was evaluated using kappa statistics. Number and percentage of fractures were analyzed by negative binomial models and chi-square tests, respectively. RESULTS: 50 children (21 females) with average age of 9.7 months, 27 of whom had follow-up radiography. Agreement on initial and follow-up X-rays was substantial (k = 0.72) and perfect (k = 1.00), respectively, and almost perfect (k = 0.82) for CT scans. Chest CT demonstrated more fractures than X-ray, both initially (112 vs. 42, p < 0.0001) and at follow-up (93 vs. 49, p < 0.0001). Significantly more additional fractures were found at CT (11/13, 84.6 %) in patients with positive than in those with negative initial surveys (7/37, 18.9 %, p < 0.001). Ten initial surveys had only indeterminate fractures; four of them had fractures and six had no fractures on CT. Chest CT missed one patient (1/27, 3.7 %) with acute nondisplaced anterior rib fractures. CONCLUSION: Chest CT can be considered in children with negative skeletal survey and high clinical suspicion for child abuse, and when the diagnosis of rib fractures is indeterminate.

Radiologists' Diagnostic Performance in Differentiation of Rickets and Classic Metaphyseal Lesions on Radiographs: A Multicenter Study.

BACKGROUND. Despite evidence supporting the specificity of classic metaphyseal lesions (CML) for the diagnosis of child abuse, some medicolegal practitioners claim that CML result from rickets rather than trauma. OBJECTIVE. The purpose of this study was to evaluate radiologists' diagnostic performance in differentiating rickets and CML on radiographs. METHODS. This retrospective seven-center study included children younger than 2 years who underwent knee radiography from January 2007 to December 2018 and who had either rickets (25-hydroxyvitamin D level < 20 ng/mL and abnormal knee radiographs) or knee CML and a diagnosis of child abuse from a child abuse pediatrician. Additional injuries were identified through medical record review. Radiographs were cropped and zoomed to present similar depictions of the knee. Eight radiologists independently interpreted radiographs for diagnoses of rickets or CML, rated confidence levels, and recorded associated radiographic signs. RESULTS. Seventy children (27 girls, 43 boys) had rickets; 77 children (37 girls, 40 boys) had CML. Children with CML were younger than those with rickets (mean, 3.7 vs 14.2 months, p < .001; 89.6% vs 5.7% younger than 6 months; 3.9% vs 65.7% older than 1 year). All children with CML had injuries in addition to the knee CML identified at physical examination or other imaging examinations. Radiologists had almost perfect agreement for moderate- or high-confidence interpretations of rickets (κ = 0.92) and CML (κ = 0.89). Across radiologists, estimated sensitivity, specificity, and accuracy for CML for moderate- or high-confidence interpretations were 95.1%, 97.0%, and 96.0%. Accuracy was not significantly different between pediatric and nonpediatric radiologists (p = .20) or between less experienced and more experienced radiologists (p = .57). Loss of metaphyseal zone of provisional calcification, cupping, fraying, and physeal widening were more common in rickets than CML, being detected in less than 4% of children with CML. Corner fracture, bucket-handle fracture, subphyseal lucency, deformed corner, metaphyseal irregularity, and subperiosteal new bone formation were more common in CML than rickets, being detected in less than 4% of children with rickets. CONCLUSION. Radiologists had high interobserver agreement and high diagnostic performance for differentiating rickets and CML. Recognition that CML mostly occur in children younger than 6 months and are unusual in children older than 1 year may assist interpretation. CLINICAL IMPACT. Rickets and CML have distinct radiographic signs, and radiologists can reliably differentiate these two entities.

Accuracy of ultrasound in the diagnosis of classic metaphyseal lesions using radiographs as the gold standard.

BACKGROUND: Diagnosis of classic metaphyseal lesions (CMLs) in children suspected for child abuse can be challenging. Ultrasound (US) can potentially help diagnose CMLs. However, its accuracy is unknown. OBJECTIVE: To evaluate the accuracy of US in the diagnosis of CMLs using skeletal survey reports as the gold standard. MATERIALS AND METHODS: US of the metaphysis was performed in three patient groups age <1 year. Informed consent was obtained for patients scheduled for renal US (Group 1) and for patients scheduled for skeletal surveys for possible child abuse (Group 2). Targeted US was also performed in selected patients to evaluate for possible CML suspected on radiographs (Group 3). In Groups 1 and 2, US was performed of both distal femurs, and of either the right or left proximal and distal tibia. Two radiologists (Rad1 and Rad2) independently reviewed the US studies, blinded to history and other imaging. US sensitivity and specificity were calculated using the following gold standards: CML definitely seen on skeletal survey (positive), CML definitely not seen on skeletal survey or part of renal US group (negative). Cases where the skeletal survey was indeterminate for CML were excluded. Kappa statistics were used to evaluate interobserver variability. RESULTS: Two hundred forty-one metaphyseal sites were evaluated by US in 63 children (mean age: 5 months; 33 males); 34 had skeletal surveys and 29 had renal US. Kappa for the presence of CML was 0.70 with 95.7% agreement. US sensitivity was 55.0% and 63.2% and the specificity was 97.7% and 96.7% for Rad1 and Rad2, respectively. CONCLUSION: US has low sensitivity and high specificity in CML diagnosis. Thus, negative US does not exclude CML, but when the radiographs are equivocal, positive US can help substantiate the diagnosis.

Establishing signs for acute and healing phases of distal tibial classic metaphyseal lesions.

BACKGROUND: Stages of healing for classic metaphyseal lesions (CMLs) are not well established. Follow-up skeletal surveys provide an opportunity to evaluate signs of healing CMLs. OBJECTIVE: To evaluate the sequence of CML healing phases by comparing initial and follow-up skeletal surveys in children with distal tibial CMLs on the initial survey. Findings could assist in child abuse investigations. MATERIALS AND METHODS: We identified all distal tibia CMLs with initial and follow-up skeletal surveys performed January 2009 through December 2018 at our institution. Two pediatric radiologists reviewed the surveys using Likert score from 1 (no CML) to 5 (definite CML). Only cases with score of 4 or 5 by both radiologists were selected for the study. The initial and 2-week follow-up skeletal surveys were reviewed in consensus for presence of the following signs: corner fracture, thin bucket handle fracture, thick bucket handle fracture, bucket handle fracture with endochondral bone filling the gap, subphyseal lucency, deformed corner, and subperiosteal new bone formation. We used the Kruskal-Wallis test to evaluate for significant difference in thickness among thin bucket handle fracture, thick bucket handle fracture, and bucket handle fracture with endochondral bone filling the gap. RESULTS: We included 26 children (12 girls) with age range 1-9.9 months who had a combined 34 distal tibia CMLs. Thin bucket handle fracture (n=13, 38.2%) was only seen on initial survey. On follow-up, six children had thick bucket handle fracture and four had bucket handle fracture with endochondral bone filling the gap. Fourteen thick bucket handle fractures (n=9) or bucket handle fractures with endochondral bone filling the gap (n=5) were noted on initial surveys; on follow-up, three (21.4%) had deformed corner, one (7.1%) had corner fracture, one (7.1%) had subphyseal lucency, and five (35.7%) were normal. None demonstrated thin bucket handle fracture on follow-up. Two of the nine (22.2%) thick bucket handle fractures became thicker, and 3/9 (33.3%) became bucket handle fractures with endochondral bone filling the gap. The metaphysis normalized in 8/34 (23.5%) CMLs on follow-up surveys. The thickness of thin bucket handle fracture was less than 1 mm (mean±standard deviation [SD] = 0.6±0.2 mm), which was significantly thinner (P<0.0001) compared with thick bucket handle fracture (1.7±0.5 mm) and bucket handle fracture with endochondral bone filling the gap (1.9±0.6 mm). CONCLUSION: The lack of thin bucket handle fractures on any follow-up skeletal surveys suggests this sign represents an acute phase of injury. The next phases of healing appear to be thick bucket handle fracture followed by bucket handle fracture with endochondral bone filling the gap. It is important to note that normalization of the metaphysis at 2-week follow-up does not exclude CML because this was seen in about one-fifth of cases.

Osteomyelitis of the ribs in children: a rare and potentially challenging diagnosis.

BACKGROUND: Rib osteomyelitis is rare in children and can mimic other pathologies. Imaging has a major role in the diagnosing rib osteomyelitis. OBJECTIVE: To evaluate clinical presentation and imaging findings in children with rib osteomyelitis. MATERIALS AND METHODS: We performed a retrospective (2009-2018) study on children with rib osteomyelitis verified by either positive culture or pathology. We excluded children with multifocal osteomyelitis or empyema necessitans. We reviewed medical charts for clinical, laboratory and pathology data, and treatment. All imaging modalities for rib abnormalities were evaluated for presence and location of osteomyelitis and abscess. We calculated descriptive statistics to compare patient demographics, clinical presentation and imaging findings. RESULTS: The study group included 10 children (6 boys, 4 girls), with an average age of 7.3 years (range, 3 months to 15.9 years). The most common clinical presentations were fever (n=8) and pain (n=5). Eight children had elevated inflammatory indices (leukocytosis, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]). Localized chest wall swelling was found initially in six children and later in two more children. Rib osteomyelitis was suspected on presentation in only two children. All children had chest radiographs. Rib lytic changes were found on only one chest radiograph, in two of the four ultrasound studies, and in four of eight CTs. Bone marrow signal abnormalities were seen in all eight MRIs. In nine children the osteomyelitis involved the costochondral junction. Six children had an associated abscess. Staphylococcus aureus was cultured in eight children. Osteomyelitis was diagnosed based on pathology in one child with negative cultures. CONCLUSION: While rib osteomyelitis is rare, imaging findings of lytic changes at the costochondral junction combined with a history of fever, elevated inflammatory markers or localized soft-tissue swelling in the chest should raise suspicion for this disease.

Ultrasound diagnosis of medial clavicular epiphysis avulsion fracture in a neonate.

Clavicle fractures are the most common bony injury that occurs during the delivery process. We present a case of medial clavicular physeal fracture mimicking sternoclavicular dislocation diagnosed by ultrasound (US) in a neonate. The infant presented to our clinic at 12 days old with improving left upper extremity pseudoparalysis and outside radiographs interpreted as left sternoclavicular dislocation. US demonstrated a displaced physeal fracture rather than a dislocation. The radiologist should be aware of this potential distinction. Our case shows the usefulness of US in obtaining the definitive diagnosis without the need for radiation or sedation, demonstrates a unique use of this modality, and illustrates that US should be considered for clarification in future cases of suspected sternoclavicular injury in the neonate.

Compliance With Skeletal Surveys for Child Abuse in General Hospitals: A Statewide Quality Improvement Process.

OBJECTIVE. The purpose of this study is to perform a statewide quality improvement process to improve compliance with the American College of Radiology (ACR) guidelines in performing skeletal surveys for suspected child abuse. SUBJECTS AND METHODS. We prospectively identified all outside hospital skeletal surveys for suspected child abuse in children younger than 3 years referred to our tertiary children's hospital in 2016-2017. We included a 3-month baseline and 21-month intervention period. The quality improvement process was based on sending educational material to all ACR member radiologists in the state and making telephone calls to radiology technologist team leaders whenever the surveys were not compliant, followed by e-mails with guidance on performing skeletal surveys. We documented the views obtained and compared them with the ACR guidelines. The percentage of compliance with each individual view was assessed with the chi-square test. The total number of compliant views per survey was evaluated with ANOVA. RESULTS. Two hundred twenty-seven patients (105 female) with a mean age of 0.8 year (SD, 0.67 year; range, 0.01-3 years) were evaluated. These 227 surveys (baseline, n = 27; postintervention, n = 200) were performed at 69 different outside hospitals. Compliance significantly (p = 0.006) improved from 25.9% (7/27) during baseline to 54.0% (108/200) after intervention. There was a nonsignificant trend of improved compliance between the first (51.9%; 41/79) and last 7-month (62.3%; 33/53) periods of intervention. Among individual views, only rib oblique views showed significantly (p = 0.02) improved compliance after the intervention, from 51.9% (14/27) to 73.5% (147/200). CONCLUSION. The compliance rate with ACR guidelines for skeletal surveys in suspected child abuse at outside general hospitals significantly increased after implementation of a quality improvement process.

The added value of a second read by pediatric radiologists for outside skeletal surveys.

BACKGROUND: Fractures are the second most common finding in non-accidental trauma after cutaneous signs. Interpreting skeletal surveys could be challenging as some fractures are subtle and due to anatomical variations that can mimic injuries. OBJECTIVE: To determine the effect of a second read by a pediatric radiologist of skeletal surveys for suspected non-accidental trauma initially read at referring hospitals by general radiologists. MATERIALS AND METHODS: In 2016 and 2017, we identified all patients referred to our children's hospital with previous surveys performed and read at a community hospital by an outside radiologist. We excluded patients older than 3 years and studies performed at a children's hospital. The surveys were reviewed by a pediatric radiologist with the printed outside report available. Surveys with disagreement between outside read and pediatric radiologist read were reviewed by a second pediatric radiologist. A disagreement in the second read included only definite discrepant findings agreed upon by both pediatric radiologists. The Fisher exact test was performed to compare the ratio of discrepancies between readers in normal and abnormal surveys. RESULTS: Two hundred twenty-five surveys were performed (120 male) at 62 referring hospitals, with a mean patient age of 10.5 months (range: 5 days-3 years). The outside read identified fractures in 104/225 (46.2%) surveys. Thirty-seven of the 225 (16.4%) contained discrepancies in interpretation (n=111). Most of these disagreements (29/37, 78.4%) resulted in a significant change in the report. There was a significant (P<0.0001) difference between disagreement rate in outside read negative (4/111, 3.2%) and positive surveys (34/104, 31.7%). The second read identified additional fractures in 22/225 (9.8%) of the surveys and disagreed with first-read fractures in 17/256 (7.6%). Four of 19 (21.1%) classic metaphyseal lesions diagnosed by the outside read were normal variants; 18 classic metaphyseal lesions were missed by the outside read. CONCLUSIONS: This study supports second reads by pediatric radiologists of skeletal surveys for non-accidental trauma.

Ultrasound diagnosis of tracheal cartilaginous sleeve in a patient with Pfeiffer syndrome.

There is an association between tracheal cartilaginous sleeve and syndromic craniosynostosis. We present a case of tracheal cartilaginous sleeve diagnosed by ultrasound (US) in a patient with Pfeiffer syndrome. The patient developed respiratory failure and was suspected at bronchoscopy to have tracheal cartilaginous sleeve. US performed before tracheostomy placement demonstrated continuous hypoechoic cartilage along the anterior surface of the trachea, confirming the diagnosis. Our report shows that US can make a definitive diagnosis of tracheal cartilaginous sleeve and raises the possibility of using US to screen for the condition in patients with syndromic craniosynostosis without the need for anesthesia or ionizing radiation.

Fishtail deformity of the distal humerus: association with osteochondritis dissecans of the capitellum.

BACKGROUND: Fishtail deformity is a rare deformity of the humerus exhibiting concavity of the lateral trochlea, resulting in ulnotrochlear joint derangement. We wanted to share our experience that osteochondritis dissecans of the capitellum is a common associated complication. OBJECTIVE: To summarize imaging of fishtail deformity in children centered on complications of the radiocapitellar joint. MATERIALS AND METHODS: From the radiology information system, we identified all patients <18 years with the diagnosis of fishtail deformity. We included only patients with V-shaped deformity of the distal humerus due to concavity at the lateral trochlea (fishtail deformity). Each patient's initial injury, most recent radiograph and available MRI were evaluated for radiocapitellar joint derangement. RESULTS: Seven patients (4 males) with a mean age of 12.9 years (range: 9.7 to 14.4 years) were identified. Radiocapitellar joint abnormalities were identified in six patients including osteoarthritis (n=5), flattened and sclerotic capitellum (n=4), osteochondritis dissecans (2 associated with loose body, n=4) and radial head subluxation (n=2). In 4 patients, MRI detected changes of osteoarthritis (n=4), osteochondritis dissecans (n=2) and loose body (n=1) not identified on radiography. Two patients with osteochondritis dissecans underwent surgery and one patient has planned surgery. CONCLUSION: Radiocapitellar joint abnormalities (particularly, capitellar osteochondritis dissecans) are common in patients with fishtail deformities. MRI should be performed in these patients since some abnormalities, possibly requiring surgery, are not detected on elbow radiographs.

Prenatal and Postnatal Sonographic Confirmation of Congenital Absence of the Ductus Venosus in a Child with Noonan Syndrome.

The ductus venosus serves as an important vascular pathway for intrauterine circulation. This case presents a description of an absent ductus venosus in a female patient with Noonan syndrome, including both prenatal and postnatal imaging of the anomaly. In the setting of the anomalous vascular connection, the umbilical vein courses inferiorly to the iliac vein in parallel configuration with the umbilical artery. This finding was suspected based on prenatal imaging and the case was brought to attention when placement of an umbilical catheter was thought to be malpositioned given its appearance on radiography. Ultrasound imaging confirmed the anomalous course. This is in keeping with prior descriptions in the literature of an association between Noonan syndrome and aberrant umbilical venous drainage. This case illustrates the need for awareness of this condition by the radiologist, allowing for identification on radiographs and the recommendation for further confirmatory imaging. Further, the case illustrates the value of paying particular attention to the fetal course of the umbilical vessels in patients with suspected Noonan syndrome, as this population is particularly at risk for anomalous vasculature.

Changes in femoral head size and growth rate in young children with severe developmental dysplasia of the hip.

BACKGROUND: Developmental dysplasia of the hip (DDH) is known to result in smaller femoral head size in toddlers; however, alterations in femoral head size and growth have not been documented in infants. OBJECTIVE: To determine with ultrasound (US) whether femoral head size and growth are altered in infants (younger than 1 year of age) with severe DDH. MATERIALS AND METHODS: We identified all patients at our tertiary care children's hospital from 2002 to 2014 who underwent US for DDH. We included studies with at least one hip with severe DDH, defined as <25% coverage of the femoral head, and excluded teratological DDH. We constructed a control group of randomized patients with normal US studies. Two pediatric radiologists blinded to diagnosis measured bilateral femoral head diameter. Inter-reader variability and femoral head diameter difference between dislocated and contralateral normal femoral heads were evaluated. Mean femoral head diameters were compared across types of hip joint; femoral head growth rates per month were calculated. RESULTS: Thirty-seven children with DDH (28 female) were identified (median age: 33 days). The control group contained 75 children (47 female) with a median age of 47 days. Fifty-three of the 74 hips in the study group had severe DDH. Twenty-four children with DDH had completely dislocated hips (nine bilateral, five with contralateral severe subluxations). Thirteen other children had severe subluxation, two bilaterally. There was good inter-reader agreement in the normal femoral head group and moderate agreement in the severe DDH group. In the study group, severe DDH femoral head diameter was significantly smaller than their contralateral normal hip. Severe DDH femoral head diameter was significantly smaller than normal femoral head diameter in the control group. The severe DDH femoral head growth rate was slightly less but not significantly slower than normal femoral head growth rate in the study group. CONCLUSION: On US during infancy, femoral head size is significantly reduced in severe cases of DDH.

JOURNAL CLUB: Can Coronal STIR Be Used as Screening for Acute Nontraumatic Hip Pain in Children?

OBJECTIVE: The objective of this study is to evaluate whether coronal STIR MRI can be used as a screening test for nontraumatic acute hip pain in children. MATERIALS AND METHODS: From 2008 to 2012, we identified all patients younger than 18 years at our tertiary care facility who underwent pelvic MRI including coronal STIR for the following indications: acute hip pain, limping, or refusal to bear weight. Patients with a history of trauma were excluded. Each MR image was independently reviewed by four radiologists who were blinded to the clinical outcome. After first reviewing the coronal STIR images only, they then reviewed the full MRI studies in a random order different from that used for review of the coronal STIR images. The sensitivity and specificity of STIR-only images in identifying the presence of abnormality and specific diagnoses were calculated, with the full MRI study considered as the reference standard. Kappa values were calculated for STIR-only and full MRI studies. RESULTS: A total of 127 patients (67 female patients and 60 male patients; median age, 9 years; range, 5 months to 17 years) were identified. The most common abnormalities (calculated as the mean of frequency values noted by four readers) were hip effusion (52%; range, 46-58%), osteomyelitis (42%; range, 29-48%), and myositis (32%; range, 20-40%). For the detection of any abnormality, STIR-only images had a mean sensitivity of 95% and a mean specificity of 67%. For approximately one-third of STIR-only studies with true-positive results, additional abnormalities were found on full MRI studies. CONCLUSION: Coronal STIR imaging of the pelvis has high sensitivity (95%) in the detection of abnormalities associated with acute nontraumatic hip pain in children, but it often misses additional abnormalities.

Can ultrasound be used as the primary imaging in children with suspected Crohn disease?

BACKGROUND: There is growing literature on the use of ultrasound (US) for evaluation of Crohn disease in adults, but few studies have been conducted on children. Several studies demonstrated high accuracy of US in the diagnosis of Crohn disease. Using US as the primary screening imaging modality for Crohn disease can reduce health care costs, the need for sedation and ionizing radiation exposure. OBJECTIVE: The aim of our study is to determine if US can be used for screening evaluation of pediatric Crohn disease. MATERIALS AND METHODS: A prospective cohort study of pediatric patients undergoing MR enterography (MRE) for suspected or known history of Crohn disease was performed, with gray-scale and Doppler US of the terminal ileum done immediately before or after MRE. US images were interpreted by two radiologists (Reader 1 and Reader 2) not involved in image acquisition, in blinded and randomized fashion. US findings of Crohn disease including bowel wall thickening, wall stratification, increased vascularity on Doppler, lymphadenopathy, fat infiltration and extraintestinal complications were evaluated. MRE findings of terminal ileitis were considered the reference standard. Demographic data, body mass index (BMI), symptoms, and laboratory, endoscopic and histopathological data were obtained from electronic medical records. RESULTS: Forty-one patients (mean age: 13.7 years: 4.6-18.9 years) were evaluated. Mean BMI was 21.2 (range: 13-40.2); 10 patients (24.3%) were either overweight or obese. Final diagnoses were Crohn disease (n=24), ulcerative colitis (n=4) and normal/non-inflammatory bowel disease-related diagnoses (n=13). US demonstrated sensitivity of 67% and 78% and specificity of 78% and 83%, by Reader 1 and Reader 2, respectively. MRE sensitivity and specificity were 75% and 100%, respectively, compared to final clinicopathological diagnosis. Interobserver agreement between Reader 1 and Reader 2 was good (0.6< kappa <0.8). CONCLUSION: In screening for Crohn disease in children, US has limited sensitivity for detecting terminal ileitis.

Double-read of skeletal surveys in suspected non-accidental trauma: what we learned.

BACKGROUND: Missing a fracture in a child on skeletal surveys for suspected non-accidental trauma can have devastating results. Double-read has the potential to improve fracture detection. However the yield of double-read is unknown. OBJECTIVE: To determine the advantage of double-read versus single-read of radiographic skeletal surveys for suspected non-accidental trauma. MATERIALS AND METHODS: The study was performed in two phases. In the first phase (April 2013 to September 2013), double-read was performed for all skeletal surveys obtained during weekday working hours. Because we had no new double-read findings in studies initially read as negative, we conducted a second phase (January 2014 to March 2014). In the second phase we limited double-reads to skeletal surveys found positive on the first read. At the end of this period, we retrospectively performed double-read for all initially negative skeletal surveys. We excluded follow-up skeletal surveys. The difference in discrepancy (new fracture or false diagnosis of a fracture) ratio between negative and positive skeletal surveys was evaluated using the Fisher exact test, and change in discrepancy ratio between the first and second study phases was evaluated using the stratified Cochran-Mantel-Haenszel test. RESULTS: Overall in the two phases, 178 skeletal surveys were performed in 178 children (67 girls) with mean age of 9 months (range 3 days to 3.7 years). Double-read found 16 discrepancies in 8/178 (4.5%) skeletal surveys. Seven of these studies showed additional fractures (n=15). In one study, an initial read of a skull fracture was read as a variant on the second read. There was a significant (P=0.01) difference between rate of disagreement in negative skeletal surveys (1/104, 1.0%) and positive skeletal surveys (7/74, 9.5%). No significant change in disagreement rate was demonstrated between the two phases of the study (P=0.59). CONCLUSION: Double-read of skeletal survey for suspected non-accidental trauma found false-negative fractures in a few cases and rarely found false-positive diagnosis of a fracture. Double-read uncommonly found discrepancies in an initially normal skeletal survey. Limiting double-read to initially positive studies improves the yield of the double-read.

Multidetector CT diagnosis of massive hemobilia due to gallbladder polyposis in a child with metachromatic leukodystrophy.

Hemobilia secondary to gallbladder polyposis is rare in children but has been reported in a few children with metachromatic leukodystrophy. We present a case with preoperative multidetector computed tomography (MDCT) diagnosis of massive hemobilia caused by gallbladder polyposis in a patient with metachromatic leukodystrophy. Our report highlights the importance of both awareness of the association of gallbladder polyposis with other syndromes such as metachromatic leukodystrophy as well as the possibility of this entity presenting with life-threatening bleeding.

Optimization of hybrid iterative reconstruction level in pediatric body CT.

OBJECTIVE: The objective of our study was to attempt to optimize the level of hybrid iterative reconstruction (HIR) in pediatric body CT. MATERIALS AND METHODS: One hundred consecutive chest or abdominal CT examinations were selected. For each examination, six series were obtained: one filtered back projection (FBP) and five HIR series (iDose(4)) levels 2-6. Two pediatric radiologists, blinded to noise measurements, independently chose the optimal HIR level and then rated series quality. We measured CT number (mean in Hounsfield units) and noise (SD in Hounsfield units) changes by placing regions of interest in the liver, muscles, subcutaneous fat, and aorta. A mixed-model analysis-of-variance test was used to analyze correlation of noise reduction with the optimal HIR level compared with baseline FBP noise. RESULTS: One hundred CT examinations were performed of 88 patients (52 females and 36 males) with a mean age of 8.5 years (range, 19 days-18 years); 12 patients had both chest and abdominal CT studies. Radiologists agreed to within one level of HIR in 92 of 100 studies. The mean quality rating was significantly higher for HIR than FBP (3.6 vs 3.3, respectively; p < 0.01). HIR caused minimal (0-0.2%) change in CT numbers. Noise reduction varied among structures and patients. Liver noise reduction positively correlated with baseline noise when the optimal HIR level was used (p < 0.01). HIR levels were significantly correlated with body weight and effective diameter of the upper abdomen (p < 0.01). CONCLUSION: HIR, such as iDose(4), improves the quality of body CT scans of pediatric patients by decreasing noise; HIR level 3 or 4 is optimal for most studies. The optimal HIR level was less effective in reducing liver noise in children with lower baseline noise.