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Magnetic resonance imaging (MRI) plays a role in assessing retears of previously treated lateral menisci (LM). We aim to characterize the rate and pattern of arthroscopically confirmed LM retears in children with and without discoid morphology. 288 patients (312 knees) who underwent arthroscopic repair of isolated LM tears between 2018 and 2023 were identified. 20 patients (21 knees) had arthroscopically confirmed isolated LM retear. This included 11 retears of discoid lateral meniscus (DLM) and 10 retears of non-DLM. MRI correctly identified retear in 81.8% of DLM cases (n = 9) and 100% of non-DLM cases (overall 90.5%, P = 0.476). 78% of DLM cases (n = 7) had residual discoid elements. MRI is highly accurate in diagnosing retears in isolated LM injuries (90.5%). We suggest that the radiological approach to assessing meniscal retears can be similarly applied to treated discoid and non-discoid menisci. However, special attention to residual discoid elements is crucial in previously treated DLMs. [ABSTRACT FROM AUTHOR]

Objective: To assess the clinical impact of diagnostic musculoskeletal (MSK) injections on treatment decision-making in adolescent and adult patients at a children's hospital. Materials and methods: Retrospective study in patients who underwent diagnostic MSK injections by fluoroscopy or ultrasound (US) between 8/2020 and 3/2023 at a children's hospital. Patients received ropivacaine and triamcinolone acetonide at pain site, reporting quantitative FACES pain score prior to, immediately following, and 2–3 days following injection. Impact on patient care was subsequently assessed. Results: A total of 109 diagnostic fluoroscopic or US MSK injection referrals (mean: 17.6 years old) were included, most commonly hip (76.2%), ankle (9.2%), and iliopsoas tendon sheath (8.3%). Pain improvement occurred in 89.0% immediately and 67.9% 2–3 days after MSK injection, with net 84.4% exhibiting improvement based on pain scores and clinical exams. When there was pain improvement at the site of injection, there was a statistically higher incidence of operative intervention or additional therapeutic injections compared with the cohort that did not have symptom improvement (88% versus 35.3%, P < 0.0001). For the 15.6% (N = 17) of referrals that did not have pain improvement, 17.6% (n = 3) ultimately had an operative intervention at a separate site from the diagnostic injection, as an alternative etiology for the pain was found. Conclusion: Image-guided MSK injections play an important role in the management of musculoskeletal disorders. 84.4% of referrals experienced symptom relief, improving confidence for treatment decision-making. Importantly, 15.6% of patients were found to have an alternative etiology for symptoms, altering management altogether. [ABSTRACT FROM AUTHOR]

Background: Magnetic resonance imaging (MRI) findings associated with athletic pubalgia are well documented in the adult literature. Objective: To describe the spectrum of MRI findings in adolescents with pubic symphyseal injuries/athletic pubalgia. Materials and methods: This is an institutional review board approved, retrospective study of all patients < 18 years who were referred for MRI, over the last 10 years. Two pediatric musculoskeletal radiologists evaluated the MRI in consensus for the following findings: Chronic Salter-Harris (SH)-I equivalent fracture or asymmetric parasymphyseal ossific fraying, non-retractile muscular tear or retraction, and edema of the aponeurosis and arcuate ligament. Radiographs were also reviewed for Risser stage. Results: Fifteen patients were identified (100% male, median age 17 years, IQR 16–17.6). Most patients (14/15, 93%) had either asymmetric parasymphyseal ossific fraying (4/15, 27%) or chronic SH-1 equivalent fracture (10/15, 67%) of the pubic symphysis, and all patients (15/15, 100%) had aponeurotic and arcuate ligament edema. Few patients had rectus abdominis muscular retraction (2/15, 13%), non-retractile muscular tear of the rectus abdominis (2/15, 13%), and/or adductor muscle (4/15, 27%). Risser stage was as follows: stages 0 (13%), 3 (7%), 4 (47%), and 5 (33%). The injuries in our limited data set were independent of skeletal maturity with no statistically significant association between any of the MRI findings and Risser stage. Conclusion: The MR imaging spectrum of adolescent athletic pubalgia differs from the described findings in adults due to skeletal immaturity. The cleft sign described in adults manifests in adolescents as asymmetric parasymphyseal ossific fraying and chronic SH-1 equivalent fractures. [ABSTRACT FROM AUTHOR]

Background: The modified Gartland classification is the most widely accepted grading method of supracondylar humeral fractures among orthopedic surgeons and is relevant to identifying fractures that may require surgery. Objective: To assess the interobserver reliability of the modified Gartland classification among pediatric radiologists, pediatric orthopedic surgeons, and pediatric emergency medicine physicians. Materials and methods: Elbow radiographs for 100 children with supracondylar humeral fractures were retrospectively independently graded by two pediatric radiologists, two pediatric orthopedic surgeons, and two pediatric emergency medicine physicians using the modified Gartland classification. A third grader of the same subspecialty served as a tie-breaker as needed to reach consensus. Readers were blinded to one another and to the medical record. The modified Gartland grade documented in the medical record by the treating orthopedic provider was used as the reference standard. Interobserver agreement was assessed using kappa statistics. Results: There was substantial interobserver agreement (kappa = 0.77 [95% CI, 0.69−0.85]) on consensus fracture grade between the three subspecialties. Similarly, when discriminating between Gartland type I and higher fracture grades, there was substantial interobserver agreement between specialties (kappa = 0.77 [95% CI, 0.66−0.89]). The grade assigned by pediatric radiologists differed from the reference standard on 15 occasions, pediatric emergency medicine differed on 19 occasions, and pediatric orthopedics differed on 9 occasions. Conclusion: The modified Gartland classification for supracondylar humeral fractures is reproducible among pediatric emergency medicine physicians, radiologists, and orthopedic surgeons. [ABSTRACT FROM AUTHOR]

This review describes our institution's standardized technique as well as potential pitfalls for therapeutic steroid injections in children with symptomatic neuromuscular hip dysplasia. Symptomatic, painful neuromuscular hip dysplasia can dramatically affect quality of life. Steroid injections are used to identify the source of perceived pain, temporarily treat pain while awaiting surgical intervention, or for therapeutic management for nonoperative hip joints. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Foreign body (FB) ingestion is common in children, particularly from 6 months to 3 years of age. As young children may be unable to provide a clinical history and the ingestion is often unwitnessed, imaging plays an important role in diagnosis, predicting outcomes and detecting complications that require surgical intervention. Since 2015, our institution's diagnostic algorithm for suspected airway foreign bodies has included a noncontrast airway FB CT (FB-CT) with the z-axis coverage spanning from the larynx to the proximal segmental bronchi of the lower lung zones. The effective dose of radiation from this FB-CT airway protocol is typically less than 1 mSv, compared to an effective dose of just under 1 mSv to up to 3 mSv for a fluoroscopic esophagram in children under 10 years of age and 1–3 mSv for a routine pediatric CT chest. In using the FB-CT airway protocol at our institution, we observed that esophageal rather than airway FBs were sometimes encountered on these exams. However, the confidence among radiologists for definitively diagnosing an esophageal foreign body on noncontrast CT was variable. Consequently, we created a teaching module of positive cases for our group of 21 pediatric body radiologists to increase their diagnostic confidence. This pictorial essay illustrates our institutional experience and can help others to confidently diagnose esophageal foreign bodies using a dedicated CT foreign body imaging protocol. At a similar radiation dose to a fluoroscopic esophagram, CT provides the additional advantage of an expedited diagnosis without the need for a radiologist on site. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The value of obtaining second-opinion interpretations by specialty radiologists has been established. In pediatric radiology, this has primarily been explored in general terms, comparing tertiary pediatric radiologists' interpretations to referral reads. In adults, second reads by subspecialty radiologists have been shown to yield changes in patient management, including in neuroradiology, musculoskeletal radiology and oncological radiology. Here, we examine second-opinion reads by pediatric radiologists by reviewing the pediatric and adult subspecialty literature. We also present our experience in providing subspecialty outside reads, summarizing lessons learned in implementing a system for outside interpretations into a pediatric radiology practice. [ABSTRACT FROM AUTHOR]

Background: Recently developed convolutional neural network (CNN) models determine bone age more accurately than radiologists.Objective: The purpose of this study was to determine whether a CNN and radiologists can accurately predict bone age from radiographs using only the index finger rather than the whole hand.Materials and Methods: We used a public anonymized dataset provided by the Radiological Society of North America (RSNA) pediatric bone age challenge. The dataset contains 12,611 hand radiographs for training and 200 radiographs for testing. The index finger was cropped from these images to create a second dataset. Separate CNN models were trained using the whole-hand radiographs and the cropped second-digit dataset using the consensus ground truth provided by the RSNA bone age challenge. Bone age determination using both models was compared with ground truth as provided by the RSNA dataset. Separately, three pediatric radiologists determined bone age from the whole-hand and index-finger radiographs, and the consensus was compared to the ground truth and CNN-model-determined bone ages.Results: The mean absolute difference between the ground truth and CNN bone age for whole-hand and index-finger was similar (4.7 months vs. 5.1 months, P=0.14), and both values were significantly smaller than that for radiologist bone age determination from the single-finger radiographs (8.0 months, P<0.0001).Conclusion: CNN-model-determined bone ages from index-finger radiographs are similar to whole-hand bone age interpreted by radiologists in the dataset, as well as a model trained on the whole-hand radiograph. In addition, the index-finger model performed better than the ground truth compared to subspecialty trained pediatric radiologists also using only the index finger to determine bone age. The radiologist interpreting bone age can use the second digit as a reliable starting point in their search pattern. [ABSTRACT FROM AUTHOR]

This study utilized hyperspectral imaging technology to identify eight tree species at the leaf level. The successive projections algorithm (SPA), information gain (IG), and Gini index (Gini) were used to select the feature bands. Furthermore, the binary particle swarm optimization (BPSO) algorithm was used to optimize the feature bands selected by SPA, IG, and Gini. The particle swarm optimization–extreme learning machine (PSO–ELM), linear Bayes normal classifi er (LBNC), and k-nearest neighbor (KNN) recognition models for tree species were established based on all bands, feature bands, and optimized feature bands, respectively. The experimental results show that the recognition rates of the PSO–ELM, LBNC, and KNN models based on all bands were 98.45, 99.10, and 83.67%, respectively. The SPA, IG, and Gini models can all effectively select spectral bands on tree species discrimination and greatly reduce the dimension of spectral data, in which the recognition effects of the models based on the feature bands selected by Gini were the best, and the recognition rates of the PSO–ELM, LBNC, and KNN models reached 97.55, 96.53, and 80.5%, respectively. Additionally, BPSO–SPA, BPSO–IG, and BPSO–Gini models can all further reduce the dimension of spectral data on the basis of ensuring the recognition accuracy of models, in which the models established based on the optimized feature bands selected by BPSO–Gini achieved the best recognition effect and the recognition rates of the PSO–ELM, LBNC, and KNN models reached 96.53, 96.68, and 81.05%, respectively. In general, the recognition performance of the PSO–ELM model was better than those of the LBNC and KNN models. [ABSTRACT FROM AUTHOR]

Objective: Pre-authorization processes are often used by medical insurance companies to reduce costs by managing the utilization of advanced diagnostic imaging, and their impact on patient care is unclear. The purpose of our study is to determine if a pre-authorization process increases the rate of surgically significant abnormal knee MRI and surgical referrals compared with patients referred from pediatric orthopedic specialists who do not undergo a pre-authorization process.Materials and Methods: A retrospective study was performed; 124 patients were identified who were referred for knee MRI by a pediatric orthopedist. The study population included patients who underwent an insurance pre-authorization process and the control group consisted of those who did not. The results of the MRI and whether they were deemed surgically significant, in addition to surgical referral, were recorded and compared.Results: The study and control groups showed no statistically significant difference in outcome with regard to surgically significant findings on MRI (p = 0.92) or whether the patient required surgery (p = 0.6).Conclusions: In this population, there is no difference in the likelihood of an abnormal knee MRI demonstrating surgically significant findings or referral to surgery in patients who did and those who did not undergo an insurance pre-authorization process when patients are referred from a pediatric orthopedic specialist. The insurance pre-authorization process does not appear to have an impact on patient diagnosis and treatment and may unnecessarily add bureaucracy and costs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: According to anecdotal press reports, there have been medically significant ingestions of fidget spinner toys, including ingestions that required endoscopic intervention. Fidget spinners have been marketed to improve attention and have been suggested as a therapeutic alternative to medications in children with attention deficit hyperactivity disorder (ADHD).Objective: To describe the radiographic appearance and features of ingested fidget spinner components. To evaluate clinical significance via rates of endoscopic intervention, incidence in patients on ADHD medications, and mean age compared to other accidental foreign body ingestions.Materials and Methods: A nested retrospective case control study analyzed pediatric accidental foreign body ingestions identified via electronic medical record search between March 1, 2017, and Feb. 28, 2018. Radiographic identifiability, component type and maximum diameter of ingested fidget spinner components were described. A nested cohort of non-fidget spinner ingestions between May 1 and Aug. 31, 2017, was compared with the fidget spinner ingestions for rates of endoscopic intervention (a), concomitant use of ADHD medication (b) and mean age (c) using the Fisher exact test (a and b) and independent samples t-test (c).Results: There were 1,095 unintentional foreign body ingestions. Ten were ingested fidget spinner component ingestions. Eight of the 10 ingested components were radiographically identifiable. Compared with the nested cohort of non-fidget spinner ingestions, fidget spinner ingestions were more likely to undergo endoscopic intervention (P=0.009, 5/10 fidget spinner ingestions vs. 54/383 other ingestions). Fidget spinner patients were more likely to be on ADHD medication (P=0.011, 2/10 fidget spinners vs. 5/383 other). Fidget spinner mean patient age was significantly older than other ingestions (P=0.015, mean: 7.1 years fidget spinner ingestions vs. 4.0 years for other ingestions).Conclusion: Compared with other foreign body ingestions, patients who ingested fidget spinner components were more likely to undergo endoscopic intervention, had a higher rate of ADHD medication use and were older. Familiarity with the radiographic appearance of ingested fidget spinner components is important for patient management. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Extrarenal rhabdoid tumor is a rare, highly aggressive tumor of childhood with a poor prognosis. It represents <1% of pediatric soft tissue malignancies, typically involving infants . Frequently involved extrarenal sites include deep locations of the neck, abdomen, and paraspinal regions. The presence of "rhabdoid" cells is the characteristic histologic feature. Recent discovery of a specific genetic mutation enables a more accurate diagnosis. We present a case in an adolescent of extrarenal rhabdoid tumor arising within the sacral canal. This appears to be the first reported case of an extrarenal rhabdoid tumor arising within the sacral canal and mimicking a peripheral nerve sheath tumor. While rare, this tumor can be included in the radiologic differential diagnosis of peripheral nerve sheath tumors in children. [ABSTRACT FROM AUTHOR]

Purpose: Spica magnectic resonance imaging (MRI) is an established technique for postoperative determination of hip reduction in patients treated for developmental dysplasia of the hip (DDH). A hip abduction angle >55° is considered excessive and has been associated with epiphyseal osteonecrosis. Our purpose was to establish objective criteria for measuring hip abduction angles on MRI after hip reduction and spica casting in patients with DDH, and evaluate reproducibility and reliability of angle measurement using these criteria. Methods: Forty patients with DDH at our institution who underwent spica MRI after hip reduction between 3 April 2008 and 3 March 2015 were identified. Hip abduction angles were measured on proton density axial images as follows. A transverse line was drawn connecting the posterior ischial tuberosities. A second line was drawn medially along the distal femoral diaphysis, and the angle between these two lines was measured; this value was subtracted from 90°, yielding the degree of abduction from midline. Measurements were independently performed by three faculty radiologists, one orthopedist, and one radiology resident. Inter-reader and intra-reader reliability was assessed using intraclass correlation (ICC), with 0 representing no agreement and 1 representing perfect agreement. Results: For inter-reader reliability, the ICC of the five physicians was 0.89 (95 % CI 0.84-0.92). For intra-reader reliability, the ICC of the five physicians ranged from 0.90−0.97 (95 % CI 0.85-0.98). The mean standard deviation of hip abduction angle measurement among readers was 3.6°. Conclusion: The proposed hip abduction angle measurement criteria for spica MRI are both reproducible and easy to perform. The high ICC and low standard deviation of independently evaluated hip abduction angles indicates high reproducibility of measurement. This applies to both inter- and intra-reader reliability. [ABSTRACT FROM AUTHOR]

The catalytic activities for benzene oxidation and resistance to SO poisoning were tested for a series of Pd/La-Cu-Co-O/cordierite catalysts, which were prepared using a multiple-step impregnation method. The XRD, SEM, and IR characterization techniques were performed to investigate the relationship between the catalytic performance and its physicochemical properties. When Pd/La-Cu-Co-O/cordierite catalysts with Pd loadings of 0.06 and 0.08 % were prepared at a calcination temperature of 500 °C for 5 h, they exhibited similar catalytic activity and sulfur resistance. When the concentration of benzene was 1500 ppm and the GHSV was 20000 h, the benzene conversion was above 95 % at a reaction temperature of 350 °C in SO existing at 100 ppm. These results were mainly attributed to the cooperation between La-Cu-Co-O perovskite and the noble metal Pd. Specifically, the addition of copper can strengthen the catalytic activity of La-Co-O/cordierite catalysts by decreasing the crystalline size of the active ingredients. A moderate Pd addition can drastically improve the sulfur resistance and further improve the catalytic activity of the La-Cu-Co-O/cordierite catalyst. [ABSTRACT FROM AUTHOR]

Background: Joint effusions identified by MRI may accompany osteomyelitis and determining whether the joint effusion is septic or reactive has important implications on patient care. Objective: Determine the incidence of epiphyseal marrow edema, joint effusions, perisynovial edema and epiphyseal non-enhancement in the setting of pediatric metaphyseal osteomyelitis and whether this may be used to predict coexisting septic arthritis. Materials and methods: Following IRB approval, we retrospectively evaluated children who underwent MRI and orthopedic surgical consultation for suspected musculoskeletal infection between January 2011 and September 2013. Criteria for inclusion in the study were microbiologically/pathologically proven infection, MRI prior to surgical intervention, long bone involvement and age 0-18 years. MRI exams were independently reviewed by two faculty pediatric radiologists to confirm the presence of appendicular metaphyseal osteomyelitis, to evaluate extent of edema, to determine subjective presence of a joint effusion and to assess perisynovial edema and epiphyseal non-enhancement. Any discrepant readings were reviewed in consensus. Charts and operative notes were reviewed to confirm the diagnosis of osteomyelitis and septic arthritis. Results: One hundred and three joints with metaphyseal osteomyelitis were identified (mean age: 7.1 years; M:F 1.3:1), of whom 53% (55/103) had joint effusions, and of those, 75% (41/55) had surgically confirmed septic arthritis. The incidence of coexisting septic arthritis was 40% in the setting of epiphyseal edema, 74% in epiphyseal edema and effusion, 75% with perisynovial edema, 76% with epiphyseal non-enhancement and 77% when all four variables were present. Of these, the only statistically significant variable, however, was the presence of a joint effusion with a P-value of <0.0001 via Fisher exact test. Statistical significance for coexisting septic arthritis was also encountered when cases were subdivided into intra-articular vs. extra-articular metaphyses ( P-value = 0.0499). No statistically significant difference was found between patients younger than 24 months and those older than 24 months. Conclusion: Patients with joint effusions identified by MRI, in the setting of metaphyseal osteomyelitis, should be presumed to have septic arthritis until proven otherwise. Epiphyseal extension of edema, perisynovial edema and epiphyseal non-enhancement in the setting of metaphyseal osteomyelitis are not helpful predictors in differentiating reactive and pyogenic joint effusions. Osteomyelitis at a site with an intra-articular metaphyses, however, is more likely to have concurrent septic arthritis. [ABSTRACT FROM AUTHOR]

Background: Fragmentary ossification of the inferior patella is often dismissed as a normal variant in children younger than 10 years of age. Objective: The purpose of this study was to determine whether fragmentary inferior patellar pole ossification is a normal variant or is associated with symptoms or signs of pathology using MRI and clinical exam findings as reference. Materials and methods: A retrospective review was performed on 150 patients ages 5-10 years who underwent 164 knee radiography and MRI exams (45.1% male, mean age: 7.8 years). The presence or absence of inferior patellar pole fragmentation on radiography was correlated with the presence or absence of edema-like signal on MR images. Clinical notes were reviewed for the presence of symptoms or signs referable to the inferior patellar pole. These data were compared with a 1:1 age- and sex-matched control group without inferior pole fragmentation. Statistical analysis was performed using two-tailed t-tests. Results: Forty of 164 (24.4%) knee radiographs showed fragmentary ossification of the inferior patella. Of these 40 knees, 62.5% (25/40) had edema-like signal of the inferior patellar bone marrow compared with 7.5% (3/40) of controls ( P = 0.035). Patients with fragmentary ossification at the inferior patella had a significantly higher incidence of documented focal inferior patellar pain compared with controls (20% vs. 2.5%, P = 0.015). Conclusion: Inferior patellar pole fragmentation in children 5 to 10 years of age may be associated with localized symptoms and bone marrow edema-like signal and should not be routinely dismissed as a normal variant of ossification. [ABSTRACT FROM AUTHOR]

A second generation proton beam writing (PBW) system has been built at the Centre for Ion Beam Applications at the National University of Singapore for fabrication of high aspect ratio 3D nano lithographic structures. System improvements and a few lithographic structures obtained with this facility are presented in this paper. Through accurate alignment of the magnetic quadrupole lenses and the electrostatic scanning system, orthogonal beam scanning has been achieved. The earlier constrain of limited beam scan area has been overcome by adopting a combination of beam and stage scanning as well as stitching. With these improvements smallest ever Ni structure of 65 nm in width has been fabricated using nickel electroplating on a proton beam written PMMA sample in the second generation PBW facility. Using this improved PBW facility, we have also demonstrated the fabrication of fine lithographic patterns with 19 nm line width and 60 nm spacing in 100 nm thick negative high resolution hydrogen silsesquioxane resist. Future possible system improvements leading to finer resolution will be discussed briefly. [ABSTRACT FROM AUTHOR]

Proton beam writing (PBW) is a new direct-write technique which has shown great potential to fabricate structures down to 20 nm level in resist material. Protons can be accelerated up to a high energy (3.5 MeV) at Centre for Ion Beam Applications. Because the mass of a proton is much larger than the mass of an electron (m:m = 1,800:1), the energy of the secondary electrons is very small compared with secondary electrons generated by electron beam lithography. Therefore, a proton will travel along a straight path into resist and secondary electrons will only expose the resist within several nanometers around the path of the proton. PBW is capable of fabricating structures with very straight, vertical and smooth sidewalls without proximity effect. This is very important when combining PBW with Ni electroplating and nanoimprinting as well as injection molding. High quality Ni molds with smooth and vertical side walls are critical in nanoimprint lithography and injection molding. In our experiments, several new resists including AR-P 3250, a mixture of AR-P 3250 and AR 300-12, and ma-N 2401 are tested with PBW for the production of high aspect ratio Ni molds and thermoplastic replication with these molds. High aspect ratio structures (up to 7) are fabricated at a width of 500 nm in Ni molds. The structures are transferred to plastic via nanoimprinting and injection molding. [ABSTRACT FROM AUTHOR]

Three-dimensional printing called rapid prototyping, a technology that is used to create physical models based on a 3-D computer representation, is now commercially available and can be created from CT or MRI datasets. This technical innovation paper reviews the specific requirements and steps necessary to apply biomedical 3-D printing of pediatric musculoskeletal disorders. We discuss its role for the radiologist, orthopedist and patient. [ABSTRACT FROM AUTHOR]

Background: The added value of routine contrast-enhanced MR imaging in children with classic findings of osteonecrosis on unenhanced MR images has not been determined. Objective: Our purpose was to determine the added value of routine contrast-enhanced MR sequences for identifying complications of osteonecrosis. Material and methods: Sixty-four patients who underwent 139 contrast-enhanced MR examinations were retrospectively identified. Unenhanced images and subsequently both unenhanced and enhanced images were reviewed in consensus. The location of osteonecrosis and the presence of complicating features (epiphyseal collapse, marrow edema, joint effusion, soft tissue edema) were recorded. Cohen's kappa coefficients (κ) were calculated to assess agreement. Results: A diagnosis of classic osteonecrosis was made in 22.3% of unenhanced examinations and 28.1% of enhanced examinations (κ = 0.734, P < 0.001). Among patients with complicated osteonecrosis, unenhanced images interpreted without and with contrast-enhanced images showed epiphyseal collapse in 51.2% and 42.5% (κ = 0.796, P < 0.001), marrow edema in 50.4% and 46.8% (κ = 0.727, P < 0.001), joint effusion in 44.9% and 51.2% (κ = 0.686, P < 0.001), and soft tissue edema in 12.2% and 10.1% (κ = 0.674, P < 0.001). Conclusion: The high observed agreement between the unenhanced MR images interpreted without and with contrast-enhanced images shows little marginal benefit from the use of routine contrast-enhanced imaging in children and young adults with classic findings of osteonecrosis on unenhanced MR images. [ABSTRACT FROM AUTHOR]

Magnetic vortices are characterized by the sense of in-plane magnetization circulation and by the polarity of the vortex core. With each having two possible states, there are four possible stable magnetization configurations that can be utilized for a multibit memory cell. Dynamic control of vortex core polarity has been demonstrated using both alternating and pulsed magnetic fields and currents. Here, we show controlled dynamic switching of spin circulation in vortices using nanosecond field pulses by imaging the process with full-field soft X-ray transmission microscopy. The dynamic reversal process is controlled by far-from-equilibrium gyrotropic precession of the vortex core, and the reversal is achieved at significantly reduced field amplitudes when compared with static switching. We further show that both the field pulse amplitude and duration required for efficient circulation reversal can be controlled by appropriate selection of the disk geometry. [ABSTRACT FROM AUTHOR]

Developmental dysplasia of the hip (DDH) is a spectrum disorder resulting in underdevelopment of the acetabulum. Radiographs and ultrasound are the mainstays for screening, with CT and MRI playing important roles in assessing outcome after treatment. The purpose of this article is to illustrate the use of multimodality imaging in the diagnosis and management of DDH. [ABSTRACT FROM AUTHOR]

Juvenile idiopathic arthritis (JIA) represents a spectrum of non-pyogenic inflammatory arthritides affecting children. The purpose of this pictorial review is to illustrate the imaging spectrum of JIA and the role of radiology in disease diagnosis and management. [ABSTRACT FROM AUTHOR]

Identification of congenital and acquired etiologies causing alignment disorders and leg-length discrepancies (LLD) in children is important for management. Minor differences in the lengths of the lower extremities are considered a normal variation and usually have no clinical significance. However, LLD of greater than 1 cm can cause altered biomechanics, resulting in scoliosis, back and lower extremity joint pain, pelvic tilt, abnormal gait and premature degenerative joint disease. The purpose of this pictorial essay is to review the imaging spectrum of growth arrest and resultant alignment and leg-length discrepancies in children. [ABSTRACT FROM AUTHOR]

Precise localization of affected compartments of the wrist and ankle in children with an established diagnosis of juvenile idiopathic arthritis (JIA) is clinically challenging. The purpose of this paper is to describe our experience utilizing a pre-injection MRI protocol of the wrist and ankle for localizing disease activity followed by fluoroscopically guided joint injections in children with JIA. [ABSTRACT FROM AUTHOR]

Direct write nanolithographic techniques are powerful techniques to fabricate masters for nano-imprint lithography (NIL). Proton beam writing (PBW) is a relatively new technique which has shown great potential in fabricating three-dimensional (3D) nanostructures in polymer resist material down to the 20 nm level. MeV protons generate secondary electrons and like in many lithographic processes these electrons modify the molecular structure of the resist. The energies of the proton induced secondary electrons are relatively low compared with secondary electrons generated using electron beam writing, therefore proton induced secondary electrons only modify resist material within several nano meters of the proton track. Since protons mainly interact with the substrate electrons the path of the proton beam is very straight, resulting in smooth and well defined resist structures with practically no proximity effects. Further development of current proton beam technology, required to approach sub 10 nm structuring with MeV protons is discussed. To explore the full micro- and nano-fabricating capabilities of PBW it is important to investigate potential new resist materials. In PBW mass production can be achieved through the fabrication of reliable molds and stamps. The compatibility of MeV proton beams for resist materials and post processing steps like electroplating and resist removal are evaluated. The second focus of this paper is PDMS nanofluidic lab on a chip sorting devices using high quality Ni molds. These molds have been prepared via PBW and Ni electroplating, a release layer on a Ni mold allows fine feature replication down to the 300 nm level with high aspect ratios in PDMS. [ABSTRACT FROM AUTHOR]

Background: Although the abdominopelvic CT findings of abdominal trauma in children have been described, little has been written about the subset of children who are victims of abuse. Objective: Our purpose is to describe abdominopelvic injuries in abused pre-school-age children as identified on CT. Materials and methods: An IRB-approved retrospective review of our institutional child abuse registry was performed. Searching a 14-year period, we identified 84 children ≤ 5 years of age with medically diagnosed abuse who underwent CT. We reviewed imaging studies, operative reports, autopsy findings and patient outcomes. Consensus review of the CT examinations was performed by CAQ-certified pediatric radiologists, and findings were categorized as normal or by injury types (solid organ versus bowel). The injuries were analyzed in light of existing literature on pediatric accidental and non-accidental injuries. Results: Of the 84 children, 35 (41.7%) had abdominal injuries. Abdominal injuries included liver (15), bowel (13), mesentery (4), spleen (6), kidneys (7), pancreas (4) and adrenal glands (3). Of these children, 26% (9/35) required surgical intervention for bowel, mesenteric and pancreatic injuries. Another 9/35 children died, not as a result of abdominal injuries but as a direct result of inflicted intracranial injuries. Conclusion: Our data indicate that abdominal injuries in abused children present in a pattern similar to that of children with accidental abdominal trauma, underscoring the need for vigilance and correlative historical and clinical data to identify victims of abuse. Mortality in abused children with intra-abdominal injury was frequently related to concomitant head injury. [ABSTRACT FROM AUTHOR]

Spica MRI is a fast and effective tool to assess morphology after closed reduction for developmental dysplasia of the hip (DDH) without the need for sedation. The multiplanar capabilities allow depiction of coronal and axial reduction of the hips. Due to MRI's inherent ability to delineate soft tissue structures, both intrinsic and extrinsic obstacles to failed reduction may be identified. Technical and interpretative challenges of spica MRI are discussed. [ABSTRACT FROM AUTHOR]

Background: Epiphyseal cartilage enhancement defects (ED) may occur in the setting of epiphyseal osteomyelitis (OM), and its significance is uncertain. Objective: The aim of this study is to evaluate the incidence and clinical impact of epiphyseal cartilage ED in pediatric epiphyseal OM. Materials and methods: The 13 children involved in this retrospective review were younger than 6 years of age and diagnosed with OM. They underwent contrast-enhanced MRI and surgical exploration yielding 14 study epiphyses. Seventeen age-matched children without evidence of infection who underwent contrast-enhanced MRI in the same period yielded 28 control epiphyses. Images were reviewed for focal/global ED, correlated with cartilage abscesses and compared with surgical reports. Results: Study and control ED were respectively present in 10/14 (71.4%-6 global, 4 focal) and 6/28 (21.4%-0 global, 6 focal), P = 0.0017. An analysis of ED patterns between study and control patients showed significant difference for global ( P = 0.0006), but no difference for focal ED ( P = 0.71). For the six study epiphyses with global ED, epiphyseal abscesses were present in two (33.3%). For the four study epiphyses with focal ED, epiphyseal abscesses were present in two (50%). For the controls, no abnormalities were found on follow-up of epiphyses with focal ED. Conclusion: ED are seen normally but more commonly in children with OM. ED should not be confused with epiphyseal abscesses. [ABSTRACT FROM AUTHOR]

The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% ( P = 1.00) and specificity was 96% and 96% ( P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% ( P = 1.00) and specificity was 98% and 98% ( P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% ( P = 1.00) and specificity was 84% and 88% ( P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively ( P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention. [ABSTRACT FROM AUTHOR]

Chest CT after pediatric trauma is frequently performed but its clinical impact, particularly with respect to surgical intervention, has not been adequately evaluated. To assess the impact of chest CT compared with chest radiography on pediatric trauma management. Two hundred thirty-five consecutive pediatric trauma patients who had both chest CT and radiography were identified. Images were reviewed and findings were categorized and correlated with subsequent chest interventions, blinded to final outcome and management. Of the 235 children, 38.3% (90/235) had an abnormal chest radiograph and 63.8% (150/235) had an abnormal chest CT ( P < 0.0001). Chest interventions followed in 4.7% (11/235); of these, the findings could be made 1 cm above the dome of the liver in 91% (10/11). Findings requiring chest intervention included pneumothorax (PTX) and vertebral fractures. PTX was found on 2.1% (5/235) of chest radiographs and 20.0% (47/235) of chest CTs ( P < 0.0001); 1.7% (4/235) of the children received a chest tube for PTX, 0.85% (2/235) seen on chest CT only. Vertebral fractures were present in 3.8% of the children (9/235) and 66.7% (6/9) of those cases were treated with spinal fusion or brace. There were no instances of mediastinal vascular injury. Most intrathoracic findings requiring surgical management in our population were identified in the lower chest and would be included in routine abdominopelvic CT exams; this information needs to be taken into consideration in the diagnostic algorithm of pediatric trauma patients. [ABSTRACT FROM AUTHOR]

The chest radiograph is commonly used in the diagnosis and management of patients presenting with respiratory illness. The language used to describe the findings is important to ensure appropriate communication with the referring clinician and thereby optimize patient management. In this study we attempted to determine how clinicians interpret specific terms commonly used in a chest radiograph report, and to assess how these terms impact the management of children with respiratory symptoms. An online survey was distributed to 562 pediatric practitioners asking their interpretation of the terms “peripheral airway disease (PAD),” “focal airspace consolidation,” and “focal infiltrate” in a febrile child with or without wheezing. There were 112 respondents. Most practitioners defined the term “PAD” as viral pneumonia (61.5%) or asthma (56.9%), “consolidation” as atelectasis (83%) followed by pneumonia (69.6%), and “infiltrate” as pneumonia (100%), followed by atelectasis (22.3%). Practitioners were more likely to treat a nonwheezing child with antibiotics if the report stated “focal airspace consolidation” (80%) or “focal infiltrate” (100%; P=0.001). Some radiologic descriptors may lead to diverse and sometimes unintended diagnostic conclusions. Our findings support continued effort to structure and standardize the radiology report and our descriptive terminology. [ABSTRACT FROM AUTHOR]

The article discusses the three common diagnostic pitfalls related to pediatric musculoskeletal magnetic resonance imaging (MRI). They include focal marrow lesions, osteomyelitis versus primary tumor of bone and soft tissue hematomas and neoplasms. According to the author, a systematic approach to evaluating signal alterations of primary osseous or soft tissue lesions of the musculoskeletal system will facilitate accurate diagnosis and treatment of children referred for MRI.