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.

The Risk of Colonic Strictures with Colitis Following Hemolytic Uremic Syndrome: A Case Report of a Toddler.

Gastrointestinal manifestations of hemolytic uremic syndrome (HUS) are rare in pediatrics, but can have significant impact on the course of the disease. While various infectious etiologies are associated with HUS, Enterohemorrhagic Escherichia coli (EHEC) has been a focus of interest in its role in post-diarrheal HUS. We report a previously healthy 3-year-old boy who presented with bloody diarrhea, was found to be EHEC positive, and developed gastrointestinal complications of HUS including chronic colitis and strictures. The case illustrates that, though rare, HUS can have long-term gastrointestinal effects.

System-specific evaluation of the dual flip angle MRI technique for quantitative T1 measurement.

PURPOSE: To investigate if the accuracy of the dual flip angle (DFA) technique for T1 measurement is affected by the system-specific RF excitation performance. METHODS: A T1 phantom, made of 12 vials of unique T1 value ranging approximately from 200 ms to 2000 ms, was built and tested on seven different clinical scanners. For each experiment, the reference T1 of each vial was obtained by the inversion recovery-based technique, and the DFA technique was applied repeatedly with several flip angle (FA) pairs conventionally proposed as optimal. The accuracy of the DFA technique for each FA pair was then evaluated by comparing the measured T1 values for the vials to the references. Any variation of the accuracy was then evaluated across different FA pairs, and across different MRI systems. To improve accuracy with a selected FA pair, the signal ratio (SR) curve, obtained from the phantom, was utilized in a calibration strategy of the DFA technique. RESULTS: When combined for all the vials, the average ratio of the measured T1 to the reference generally increased as the FA pair window gradually slid from the smaller to the larger FA values. Furthermore, among several optimal FA pairs, the pair of the best accuracy varied slightly by the MRI system. The accuracy for any FA pair could be improved when the calibration strategy was utilized. CONCLUSIONS: The RF excitation performance may vary by the specific FA pair and by the specific MRI system, influencing the accuracy of the DFA technique. The system-specific evaluation, and, if needed, its calibration, would help improve the accuracy of the DFA technique.

Comparison of 2D, 3D, and radially reformatted MR images in the detection of labral tears and acetabular cartilage injury in young patients.

OBJECTIVE: The purpose of this study was to compare the utility of two-dimensional high-resolution (2D), 3-dimensional with multiplanar reconstruction (3D MPR), and radially reformatted (RR) MRIs when evaluating the complexities of the hip joint in patients with femoroacetabular impingement (FAI). We hypothesized RR would be superior in detecting labral pathology and 2D would be superior in detecting transition zone and acetabular cartilage injury. MATERIALS AND METHODS: 2D, 3D MPR, and RR MRIs of 33 patients, who later underwent surgical treatment for FAI, were evaluated for sensitivity, specificity, and accuracy. Bland-Altman methods were used to estimate agreement between each method and the gold-standard, arthroscopic visualization of the hip joint, regarding the percentage of the hip joint affected by each injury type. RESULTS: 3D MPR and RR groupings were associated with the highest sensitivity and accuracy for labral injury. 3D MPR demonstrated the smallest bias in assessing the percentage of joint affected by labral injury and was the most accurate in identifying acetabular cartilage injury, whereas RR had the smallest mean difference in assessing the percentage of joint affected by acetabular cartilage injury. 2D was the most accurate in identifying transition zone injuries, while RR was superior in assessing the percentage of the joint affected by transition zone injury. CONCLUSIONS: Our results suggest that including both 3D MPR and RR MRI groupings is favorable for accurate joint visualization and well-informed treatment planning, especially given that labral injury is a main source of pain and dysfunction for FAI patients.

Young adult outcomes of childhood prophylaxis for severe hemophilia A: results of the Joint Outcome Continuation Study.

The Joint Outcome Study (JOS), a randomized controlled trial, demonstrated that children with severe hemophilia A (HA) initiating prophylactic factor VIII (FVIII) prior to age 2.5 years had reduced joint damage at age 6 years compared with those treated with episodic FVIII for bleeding. The Joint Outcome Continuation Study (JOS-C) evaluated early vs delayed prophylaxis effects on long-term joint health, following JOS participants to age 18 years in an observational, partially retrospective study. Index joint magnetic resonance imaging (MRI) scores of osteochondral (OC) damage (primary outcome), joint physical examination scores, and annualized rates of joint/other bleeding episodes (secondary outcomes) were collected. Thirty-seven of 65 JOS participants enrolled in JOS-C, including 15 randomized to prophylaxis at mean age 1.3 years ("early prophylaxis"); 18 initially randomized to episodic treatment, starting "delayed prophylaxis" at mean age 7.5 years; and 4 with high-titer inhibitors. At JOS-C exit, MRI OC damage was found in 77% of those on delayed and 35% of those on early prophylaxis for an odds ratio of OC damage, in the delayed vs early prophylaxis group, of 6.3 (95% confidence interval, 1.3, 29.9; P = .02). Annualized bleeding rates were higher with delayed prophylaxis (mean plus or minus standard deviation, 10.6 ± 6.6 vs 3.5 ± 2.1; P < .001), including when only comparing time periods on prophylaxis (6.2 ± 5.3 vs 3.3 ± 1.9; P < .05). In severe HA, early initiation of prophylaxis provided continued protection against joint damage throughout childhood compared with delayed initiation, but early prophylaxis was not sufficient to fully prevent damage. This trial was registered at www.clinicaltrials.gov as #NCT01000844.

Hearing Loss in Pediatric Septo-Optic Dysplasia.

OBJECTIVE: To identify and characterize hearing loss (HL) in children with septo-optic dysplasia (SOD). METHODS: Otologic and audiometric data for patients less than 18 years of age identified as having SOD who were seen in the Children's Healthcare of Atlanta-Scottish Rite Hospital clinic between 2013 and 2017 were collected and reviewed through a HIPAA-compliant medical record search. Relevant literature was also reviewed with the assistance of Medline. RESULTS: Sixty-four patients with SOD were identified, and 7 of those patients (10.9%) were diagnosed with hearing loss. Type of hearing loss was sensorineural (SNHL) in 5 patients (63%), mixed (MHL) in 1(14%), and conductive (CHL) in 1(14%). Bilateral loss presented in 60% (3/5) of SNHL patients, while the rest demonstrated unilateral loss. Unilateral findings included cochlear nerve deficiency (1) and atresia/microtia (1). Tympanostomy tubes were required in 57% (4/7) of SOD children with hearing loss. Amplification was successfully implemented in 86% (6/7). CONCLUSIONS: Hearing loss was found in nearly 11% of SOD children, and SNHL was identified as (63%) the predominant form of loss. To our knowledge, this is the first retrospective review of hearing loss in a pediatric SOD cohort and the first to report of cochlear nerve deficiency and atresia/microtia in this population. Based on these findings, early identification of hearing loss with imaging when appropriate and treatment of otitis in this population is recommended.

A study of radiological features of healing in long bone fractures among infants less than a year.

PURPOSE: To create a timetable for dating long bone fractures in infants aged less than 1 year using previously defined radiographic signs of fracture healing. MATERIALS AND METHODS: A retrospective cross-sectional time series of long bone fractures in infants aged less than 1 year was conducted from 2006 to 2013. After exclusion criteria were applied 59 digital image series were available for review from 40 infants. Utilizing published criteria for dating fractures, the presence or absence of four pre-defined features of healing was scored: periosteal reaction, callus, bridging, and remodeling. Three radiologists independently scored radiographs with a 3-point scale, marking each feature as present, absent, or equivocal. The times in days when features were first seen, peaked (feature agreed present in >40% of images), and last seen were noted. Statistical analysis using free marginal kappa was conducted. RESULTS: The level of agreement among the three radiologists was high (0.64-0.85). The sequence in which the features were seen was: periosteal reaction range 7-130 (present in the majority of cases between 9 and 49 days); callus range 9-130 (present in the majority of cases between days 9-26); bridging range 15-130 (seen in the majority of cases between 15 and 67 days); remodeling range 51-247 days. CONCLUSION: This study provides a timetable of radiological features of long bone healing among young infants for the first time. Dating of incomplete long bone fractures is challenging, beyond the presence of periosteal reaction, but a consistent sequence of changes is present in complete fractures.

Radiological features of healing in newborn clavicular fractures.

OBJECTIVES: Given the frequency of abusive fractures among infants, and the lack of research and or evidence for the phases of fracture healing seen in this age group, this study aims to describe a timetable of radiological features of fracture healing among infants in the first months of life. METHODS: We completed a retrospective cross-sectional time-series study of birth-related clavicle fractures from 2006-2013. A total of 108 digital images were available for review from 61 infants. The presence or absence of four features of healing including periosteal reaction, callus formation, bridging callus and remodelling were scored by three radiologists. RESULTS: The level of agreement between the radiologists was good to high (0.60-0.90). Features of healing were first seen at 7 days (periosteal reaction), 11 days (callus), 20 days (bridging) and 35 days (remodelling), respectively. The peak periods that each feature was present are as follows: periosteal reaction 11-42 days, callus 12-61 days, bridging 22-63 days and remodelling 49-59 days. CONCLUSIONS: Birth-associated clavicle fractures in infants follow a logical progression of healing changes. Understanding the expected progression and timing of fracture healing may be helpful as it pertains to the timing of injury in cases of abuse in infants. KEY POINTS: • Large study describing the time frames of fracture healing in young infants. • Features of fracture healing develop in a logical progression. • Evidence provided for determining fractures are consistent with a proposed time frame. • It is of critical importance to have sound evidence for the dating of fractures.

Confidence in Assessment of Lumbar Spondylolysis Using Three-Dimensional Volumetric T2-Weighted MRI Compared With Limited Field of View, Decreased-Dose CT.

BACKGROUND: Limited z-axis-coverage computed tomography (CT) to evaluate for pediatric lumbar spondylolysis, altering the technique such that the dose to the patient is comparable or lower than radiographs, is currently used at our institution. The objective of the study was to determine whether volumetric 3-dimensional fast spin echo magnetic resonance imaging (3D MRI) can provide equal or greater diagnostic accuracy compared with limited CT in the diagnosis of pediatric lumbar spondylolysis without ionizing radiation. HYPOTHESIS: Volumetric 3D MRI can provide equal or greater diagnostic accuracy compared with low-dose CT for pediatric lumbar spondylolysis without ionizing radiation. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 2. METHODS: Three pediatric neuroradiologists evaluated 2-dimensional (2D) MRI, 2D + 3D MRI, and limited CT examinations in 42 pediatric patients who obtained imaging for low back pain and suspected spondylolysis. As there is no gold standard for the diagnosis of spondylolysis besides surgery, interobserver agreement and degree of confidence were compared to determine which modality is preferable. RESULTS: Decreased-dose CT provided a greater level of agreement than 2D MRI and 2D + 3D MRI. The kappa for rater agreement with 2D MRI, 2D + 3D MRI, and CT was 0.19, 0.32, and 1.0, respectively. All raters agreed in 31%, 40%, and 100% of cases with 2D MRI, 2D + 3D MRI, and CT. Lack of confidence was significantly lower with CT (0%) than with 2D MRI (30%) and 2D + 3D MRI (25%). CONCLUSION: For diagnosing spondylolysis, radiologist agreement and confidence trended toward improvement with the addition of a volumetric 3D MRI sequence to standard 2D MRI sequences compared with 2D MRI alone; however, agreement and confidence remain significantly greater using decreased-dose CT when compared with either MRI acquisition. CLINICAL RELEVANCE: Decreased-dose CT of the lumbar spine remains the optimal examination to confirm a high suspicion of spondylolysis, with dose essentially equivalent to radiographs. If clinical symptoms are not classic for spondylolysis, 2D MRI is still very good at detecting spondylolysis while remaining sensitive for detection of alternative diagnoses such as disc abnormalities and pars stress reaction. The data suggest that standard 2D MRI sequences should not be entirely replaced by a volumetric T2-weighted 3D sequence (despite promising features of rapid acquisition time, increased spatial resolution, and reconstruction capability).

MRI as a reliable and accurate method for assessment of posterior hip dislocation in children and adolescents without the risk of radiation exposure.

BACKGROUND: Posterior hip dislocation in children and adolescents may involve the non-ossified posterior acetabular wall. Plain radiographs and computed tomography (CT) have been shown to underestimate injury to the unossified acetabulum as well as associated soft-tissue structures. OBJECTIVE: The purpose of this study was to describe findings on radiographs, CT and magnetic resonance imaging (MRI) after posterior hip dislocation in a series of adolescents and to report the intraoperative findings, which are considered the gold standard. Measurements of the posterior wall length using MRI and CT scans were also performed. MATERIAL AND METHODS: After institutional review board approval, 40 patients who sustained a traumatic posterior dislocation of the hip between September 2007 and April 2014 were identified. Inclusion criteria were (1) age younger than 16 years old and (2) availability of MRI obtained following closed reduction of the hip. Eight male patients and one female patient with an average age of 13.2 years (range: 10.1-16.2 years) underwent hip MRI following posterior dislocation. Seven of the nine patients also underwent evaluation by CT. Plain radiographs, CT scans and MRI were evaluated in all patients by a single pediatric radiologist blinded to surgical findings for joint space asymmetry, posterior wall fracture, femoral head fracture, labrum tear, complete or partial ligamentum teres rupture and presence of intra-articular fragments. Six patients underwent surgical treatment and the intraoperative findings were compared with the imaging findings. RESULTS: CT identified all bone injuries but underestimated the involvement of posterior wall fractures. Assessment of the posterior wall size and fracture displacement was possible with MRI. All surgically confirmed soft-tissue injuries, including avulsion of the posterior labrum, were identified preoperatively on MRI. The measurement of posterior wall length was not statistically different using CT and MRI. CONCLUSION: Intraoperative pathological findings at the time of open surgical treatment were universally recognized on MRI but not on CT scans. MRI should be considered for evaluation of the hip following closed reduction for the treatment of a posterior dislocation in children and adolescents as it reliably allows assessment of intra-articular pathology without the risk of radiation exposure.

CT outperforms radiographs at a comparable radiation dose in the assessment for spondylolysis.

BACKGROUND: Lumbar spondylolysis, a unilateral or bilateral fracture at pars interarticularis, is a common cause of low back pain in children. The initial imaging study in the diagnosis of lumbar spondylolysis has historically been lumbar spine radiographs; however, radiographs can be equivocal or false-negative. Definitive diagnosis can be achieved with computed tomography (CT), but its use has been limited due to the dose of ionizing radiation to the patient. OBJECTIVE: By limiting the z-axis coverage to the relevant anatomy and optimizing the CT protocol, we are able to provide a definitive diagnosis of fractures of the pars interarticularis at comparable or lower radiation dose than commonly performed lumbar spine radiographs. As there is no gold standard for the diagnosis of spondylolysis besides surgery, we compared interobserver agreement and degree of confidence to determine which modality is preferable. MATERIALS AND METHODS: Sixty-two patients with low back pain ages 5-18 years were assessed for the presence of spondylolyis. Forty-seven patients were evaluated by radiography and 15 patients were evaluated by limited field-of-view CT. Both radiographic and CT examinations were assessed anonymously in random order for the presence or absence of spondylolyisis by six raters. Agreement was assessed among raters using a Fleiss Kappa statistic for multiple raters. RESULTS: CT provided a significantly higher level of agreement among raters than radiographs (P < 0.001). The overall Kappa for rater agreement with radiographs was 0.24, 0.34 and 0.40 for 2, 3 or 4 views, respectively, and 0.88 with CT. CONCLUSION: Interobserver agreement is significantly greater using limited z-axis coverage CT when compared with radiographs. Radiologist confidence improved significantly with CT compared to radiographs regardless of the number of views.

Prenatal diagnosis and postnatal follow-up of rapidly involuting congenital hemangioma (RICH).

The most common vascular tumors of infancy are hemangiomas. These are further classified as infantile or congenital. Infantile hemangiomas are not present at birth, go on to proliferate and then involute, whereas congenital hemangiomas are mature at birth. Congenital hemangiomas are further characterized as rapidly involuting (RICH) or noninvoluting (NICH). Rapidly involuting congenital hemangiomas (RICH) are more common with the majority involuting completely by 12 months of age. Noninvoluting congenital hemangiomas (NICH) never involute, demonstrate proportional growth and require eventual excision. We report a unique case of an intracranial rapidly involuting congenital hemangioma. Pre- and postnatal imaging, as well as clinical follow-up, demonstrate the rapid regression of both the intracranial and cutaneous portions of this lesion during the first year of life.