Frequency of technical success of ultrasound-guided arthrogram injections in children.

BACKGROUND: MR arthrography is an essential diagnostic tool to assess and guide management of labral, ligamentous, fibrocartilaginous, and capsular abnormalities in children. While fluoroscopy is traditionally used for intra-articular contrast administration, ultrasound offers advantages of portability and lack of ionizing radiation exposure for both the patient and proceduralist. OBJECTIVE: The purpose of this retrospective study is to quantify technical success and frequency of complications of ultrasound-guided arthrogram injections at our institution. MATERIALS AND METHODS: This retrospective analysis investigates the results of 217 ultrasound-guided arthrograms of the shoulder, elbow, and hip in patients aged 5-18 years. Successful injection of contrast into the target joint, clinical indication for MR arthrography, and complications were reviewed. RESULTS: Accurate ultrasound-guided intra-articular administration of contrast into the target joint was successful for 100% of shoulder cases (90/90), 97% of elbow cases (77/79), and 98% of hip cases (47/48). Leak of contrast outside the target joint occurred in 1.4% (3/217) of cases. No major side effects including excessive bleeding, paresthesia, allergic reactions, or infection occurred during or after the procedure. Additionally, no major vessel, nerve, or tendon complications were observed on MR images. CONCLUSION: Ultrasound guidance is a reliable, effective, and safe approach to arthrography in children.

Palpable pediatric chest wall masses.

Pediatric chest wall lesions are varied in etiology ranging from normal and benign to aggressive and malignant. When palpable, these lesions can alarm parents and clinicians alike. However, most palpable pediatric chest lesions are benign. Familiarity with the various entities, their incidences, and how to evaluate them with imaging is important for clinicians and radiologists. Here we review the most relevant palpable pediatric chest entities, their expected appearance and the specific clinical issues to aid in diagnosis and appropriate treatment.

Review of spinal involvement in chronic recurrent multifocal osteomyelitis (CRMO): What radiologists need to know about CRMO and its imitators.

We appreciate the comments written regarding our paper, "Review of spinal involvement in Chronic recurrent multifocal osteomyelitis (CRMO): What radiologists need to know about CRMO and its imitators". In this paper, we review multiple categories of mimics of CRMO. Although we do mention infectious etiology as a group, we did not specifically mention tuberculosis affecting the spine which is an important mimic of CRMO, and we acknowledge this omission.

Normative Values for the Sonographic Measurement of the Pediatric Median and Ulnar Nerves.

RATIONAL AND OBJECTIVES: Ultrasound investigation of peripheral nerves, long used in the adult population, has been shown to be of value in diagnosing a variety of peripheral nerve abnormalities. More recently, nerve sonography has also been shown to be of use in pediatrics. However, normative values for nerve size in children have been lacking. As such, the goal of this research was to establish normative data for cross sectional area (CSA) measurements of the median and ulnar nerves in children. MATERIALS AND METHODS: The median and ulnar nerves of 48 children ranging in age from 2 years to 17 years were imaged by ultrasound. CSA measurements were made at 2 separate sites for each nerve and measured independently by 6 pediatric radiologists. Reliability of ultrasound measurements between the radiologists was assessed by calculating intraclass correlation coefficients. Linear mixed-effects modeling was performed to develop prediction models for nerve cross sectional area for each nerve segment; 95% prediction values were generated from these models to approximate normal ranges. RESULTS: Agreement in nerve cross-sectional area measurements among the 6 radiologists for all nerve segments was good (ICC 0.82, 95% CI 0.78 to 0.85). CSA for both the median and ulnar nerves is larger in older children. However, statistical models to predict CSA using height perform better rather than those using a child's age. The range of normal nerve segment CSA using these prediction models based on child height are reported. CONCLUSION: Median and ulnar nerve CSA can be reliably measured with ultrasound. Normal reference values for ulnar and median nerve CSA correlate with patient age but may be more optimally determined based on a child's height.

Review of spinal involvement in Chronic recurrent multifocal osteomyelitis (CRMO): What radiologists need to know about CRMO and its imitators.

Chronic recurrent multifocal osteomyelitis (CRMO) is a distinct disease entity of unknown etiology primarily affecting children and adolescents. It is an autoinflammatory process that typically affects multiple bones with a waxing and waning course. About one third of the patients diagnosed with CRMO have spinal involvement which can lead to long term morbidity. The clinical presentation and imaging features of CRMO involving the spine are nonspecific and can mimic other disease processes like infection or malignancy. Since imaging plays a very important role in the diagnosis and management of CRMO, we intend to highlight various imaging patterns of spinal CRMO alongside its clinical features and briefly discuss its imitators, management and outcomes.

A Novel Algorithm Using Within-leg Calibration for Enhanced Accuracy of Detection of Arthritis by Infrared Thermal Imaging in Children.

OBJECTIVE: To standardize and improve the accuracy of detection of arthritis by thermal imaging. METHODS: Children with clinically active arthritis in the knee or ankle, as well as healthy controls, were enrolled to the development cohort; another group of children with knee symptoms was enrolled to the validation cohort. Ultrasound was performed in the arthritis subgroup for the development cohort. Joint exam by certified rheumatologists was used as a reference for the validation cohort. Infrared thermal data were analyzed using custom software. Temperature after within-limb calibration (TAWiC) was defined as the temperature differences between joint and ipsilateral mid-tibia. TAWiC of knees and ankles was evaluated using ANOVA across subgroups. Optimal thresholds were determined by receiver-operating characteristic analysis using Youden index. RESULTS: There were significant differences in mean and 95th TAWiC of knee in anterior, medial, lateral views, and of ankles in anterior view, between inflamed and uninflamed counterparts (P < 0.05). The area under the curve was higher by 30% when using TAWiCknee than that when using absolute temperature. Within the validation cohort, the sensitivity of accurate detection of arthritis in the knees using both mean and 95th TAWiC from individual views or all 3 views combined ranged from 0.60 to 0.70, and the specificity was > 0.90 in all views. CONCLUSION: Children with active arthritis or tenosynovitis in knees or ankles exhibited higher TAWiC than healthy joints. Our validation cohort study showed promise for the clinical utility of infrared thermal imaging for arthritis detection.

Uniquely pediatric upper extremity injuries.

The pediatric population is prone to unique upper extremity injuries that are not typically seen in adults. The normal dynamic maturation pattern of ossification centers and open physis can potentially confuse radiologists who are not familiar with the pediatric patients. In this review article, we discuss the normal anatomy and commonly encountered acute and chronic upper extremity injuries such as supracondylar distal humeral fracture and osteochondritis dissecans, in pediatric patients. Diagnosing the correct type of fracture (e.g., buckle vs Salter-Harris) is important for proper management of the injury. With an increasing number of adolescents participating in competitive sports, specific sports related injuries such as little league shoulder, gymnast wrist, and medial epicondyle apophysitis, are also discussed in this review. We examine late complications of injuries, such as physeal bar formation and fishtail deformity of the distal humerus.

Association Between 45° Flexion Anteroposterior Elbow Radiographs and Diagnostic Accuracy of Capitellum Osteochondritis Dissecans.

BACKGROUND: An anteroposterior (AP) radiograph of the elbow in 45° of flexion has been suggested to increase the diagnostic accuracy of capitellum osteochondritis dissecans (OCD). PURPOSE: To assess the diagnostic performance, inter- and intraobserver reliability, and confidence level for identifying capitellum OCD using plain radiographs (AP, lateral, and 45° flexion AP). STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: This was a retrospective study of pediatric and adolescent patients with capitellum OCD and a control group. Six independent clinicians who were blinded to the official radiologists' reports reviewed images on 2 separate occasions, 1 week apart. A 5-point Likert scale was used to assess the clinicians' level of confidence. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for individual and combinations of radiographic views. Inter- and intraobserver reliability was determined using Cohen kappa (κ) coefficients. RESULTS: A total of 28 elbows (mean age, 12.5 ± 2 years) were included. There were no differences in age (P = .18), sex (P = .62), or laterality (P > .999) between groups. There were marked variations in the diagnostic accuracy between views: sensitivity (AP, 85.1; lateral, 73.2; 45° flexion AP, 91.7), specificity (AP, 89.3; lateral, 91.7; 45° flexion AP, 91.1), PPV (AP, 88.8; lateral, 89.8; 45° flexion AP, 91.1), NPV (AP, 85.7; lateral, 77.4; 45° flexion AP, 91.6), and accuracy (AP, 87.2; lateral, 82.4; 45° flexion AP, 91.4). Standard radiographs (AP and lateral views) failed to diagnose capitellum OCD in 4.8% of cases. The sensitivity of the 3 combined views was 100%. Confidence intervals in the clinicians' diagnostic assessments were similar for each view (AP, 4.0; lateral, 4.0; and 45° flexion AP, 4.1). Interobserver reliability was substantial for AP and lateral views (κ = 0.65 and κ = 0.60, respectively) but highest for the 45° flexion AP radiographs (κ = 0.72). Intraobserver reliability for the 45° flexion AP view was moderate to almost perfect (κ = 0.45 to 0.93). CONCLUSION: The 45° flexion AP view can detect capitellum OCD with excellent accuracy, a high level of confidence, and substantial interobserver agreement. When added to standard AP and lateral radiographs, the 45° flexion AP view aids in the identification of capitellum OCD.

Prevalence and Severity of Juvenile Osteochondritis Dissecans in Patients With Juvenile Idiopathic Arthritis.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is a heterogeneous group of chronic arthritides presenting in patients aged ≤16 years, with a prevalence of 16 to 150 per 100,000. Juvenile osteochondritis dissecans (OCD) is an idiopathic disease of articular cartilage and subchondral bone, has an onset age of 10 to 16 years, and often affects the knee, with a prevalence of 2 to 18 per 100,000. Currently, there are few studies that have evaluated the relationship between JIA and OCD. HYPOTHESIS: OCD is more prevalent in children with JIA, and when diagnosed in such patients, OCD often presents at an advanced state. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The medical records of patients with diagnoses of both JIA and OCD treated between January 2008 and March 2019 at a single children's hospital were retrospectively reviewed. Associations between timing of diagnoses, number and types of corticosteroid treatments, category of arthritis, timing of diagnoses, and lesion stability were examined with Spearman correlation coefficients. RESULTS: A total of 2021 patients with JIA were identified, 20 of whom (19 female, 1 male) had OCD of the knee and/or talus for a prevalence of 1 in 100 or 1000 in 100,000, or approximately 50 to 500 times that of the general population. These 20 patients had a total of 28 OCD lesions: 43% (9 femur, 3 talus) were radiographically stable over time, 50% (10 femur, 2 patella, 2 talus) were unstable at initial diagnosis, and 7% (2 femur) were initially stable but progressed to unstable lesions despite drilling. Twelve patients (60%) underwent surgery: 4 (20%) with stable femoral lesions for persistent symptoms despite prolonged nonoperative treatment and 8 (40%) for treatment of their unstable lesions (femoral and patellar). Within our study design, we could identify no significant associations between lesion stability and timing of diagnoses, number of joint injections, or limb deformities, nor were there associations between timing of JIA and OCD diagnoses and category of arthritis. CONCLUSION: In our population of patients with JIA, OCD lesions were found to be 50 to 500 times more prevalent when compared with published rates in the general population and often presented at an advanced state, with instability or delayed healing requiring surgery for stabilization or resolution of symptoms.

Contemporary imaging of the pediatric shoulder: pearls and pitfalls.

In skeletally immature patients, the presence of growth plates and articular cartilage of the shoulder can create a predisposition for unique injuries not observed in adults. Furthermore, increasing participation in sports by children and adolescents appears to be leading to a corresponding increase in the number of sports-related injuries. The importance of radiologists being familiar with pediatric shoulder imaging and its associated injuries is therefore growing. In this article, we review the normal development and maturation pattern of ossification centers of the shoulder from the early gestational period through adolescence. Brachial plexus birth palsy, physeal injuries, shoulder dislocation, and internal impingement are discussed within the context of the child's age and the mechanism of injury to guide radiologists to a correct diagnosis.

The Many Faces of Pediatric Chronic Recurrent Multifocal Osteomyelitis (CRMO): A Practical Location- and Case-Based Approach to Differentiate CRMO From Its Mimics.

Chronic recurrent multifocal osteomyelitis (CRMO) is an autoinflammatory bone disease of childhood and adolescence characterized by episodic bone pain. Diagnosis relies heavily on whole-body MRI and is made by excluding a wide variety of other disorders with overlapping imaging features, depending on location, marrow distribution, and the presence or absence of multifocality. We present an overview of the clinical and imaging features of CRMO and, through various clinical scenarios, provide tips for tailoring the differential diagnosis based on location and distribution of encountered abnormalities. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY STAGE: 3.

Foot and Ankle Musculoskeletal Imaging of Pediatric Patients With Cerebral Palsy.

OBJECTIVE. Any combination of abnormal positioning of the ankle, hindfoot, midfoot, and forefoot is possible in the context of cerebral palsy, but some patterns are more common than others. The purpose of this article is to discuss the radiographic manifestations and surgical management of the following common conditions: equinus, equinoplanovalgus, equinocavovarus, vertical talus, oblique talus, hallux valgus, and ankle valgus. CONCLUSION. CP is defined by abnormalities of the developing fetal or infant brain that result in permanent central motor dysfunction. Foot and ankle deformities are very common in the patients with CP, occurring in up to 93% of such patients as a result of underlying abnormal muscle tone, impaired motor control, and dynamic muscle imbalance. Radiologists must develop knowledge of the most common changes in alignment and basic techniques for correction to better recognize abnormalities and improve communication with orthopedic colleagues.

Development of a Scoring Tool for Chronic Nonbacterial Osteomyelitis Magnetic Resonance Imaging and Evaluation of its Interrater Reliability.

OBJECTIVE: Serial magnetic resonance imaging (MRI) examinations are often needed in chronic nonbacterial osteomyelitis (CNO) to determine the objective response to treatment. Our objectives in this study were (1) to develop a consensus-based MRI scoring tool for clinical and research use in CNO; and (2) to evaluate interrater reliability and agreement using whole-body (WB)-MRI from children with CNO. METHODS: Eleven pediatric radiologists discussed definitions and grading of signal intensity, size of signal abnormality within bone marrow, and associated features on MRI through monthly conference calls and a consensus meeting, using a nominal group technique in July 2017. WB-MRI scans from children with CNO were deidentified for training reading and an interrater reliability study. The reading by each radiologist was conducted in a randomized order. Interrater reliability for abnormal signal and severity were assessed using free-marginal κ statistics. RESULTS: Radiologists reached a consensus on grading CNO-specific MRI findings and on describing bone units based on anatomy. A total of 45 sets of WB-MRI scans, including 4 sets of non-CNO MRI examinations, were selected for the final reading. The mean κ of each category of bones was > 0.7 with majority > 0.9 demonstrating substantial/almost perfect interrater reliability of readings among radiologists. The agreement on signal intensity and the size of signal abnormality within the most commonly affected bones (femur and tibia) were lower than those of other bones. CONCLUSION: The chronic nonbacterial osteomyelitis magnetic resonance imaging scoring (CROMRIS) tool is a comprehensive standardized scoring tool for MRI in children with CNO. Our interrater study demonstrated good interrater reliability and agreement of readings.

Cerebral palsy - beyond hip deformities.

Cerebral palsy is a neurologic condition with myriad musculoskeletal and articular manifestations. While every patient is unique with innumerable variations in presentation, symptoms and treatments, there are broad themes and recognizable patterns of development. Many of these findings spill over to other neurodevelopmental disorders, and lessons learned from children with cerebral palsy translate well to multiple neurologic conditions. This review focuses on the more common manifestations involving the spine, knee, foot and ankle, with an emphasis on collecting and describing imaging features, along with clinical and radiologic pearls and pitfalls.