Thoracic Outlet Syndrome in the Pediatric and Young Adult Population.

PURPOSE: This study aimed to assess both nonsurgical and operative treatment outcomes of pediatric and young adult patients with thoracic outlet syndrome (TOS) at a tertiary care pediatric hospital. METHODS: A retrospective chart review of patients diagnosed with TOS, who were seen between January 2010 and August 2022 at a tertiary care pediatric hospital, was conducted. Collected pre- and postoperative data included symptoms, provocative testing (ie, Roo's, Wright's, and Adson's tests), participation in sports or upper-extremity activities, additional operations, and surgical complications. Assessment of operative treatment efficacy was based on pre- and post-provocative testing, pain, venogram results, alleviation of symptoms, and return to previous activity level 6 months after surgery. RESULTS: Ninety-six patients, (70 females and 26 males) with an average age at onset of 15 ± 4 (4-25) years, met the inclusion criteria for TOS. Among them, 27 had neurogenic TOS, 29 had neurogenic and vasculogenic TOS, 20 had vasculogenic TOS, 19 had Paget-Schroetter Syndrome, and one was asymptomatic. Twenty-six patients were excluded because of less than 6 months of follow-up. Of the remaining 70, 6 (8.6%) patients (4 bilateral and 2 unilateral) underwent nonoperative management with activity modification and physical therapy only, and one was fully discharged because of complete relief of symptoms. Sixty-four (90.1%) patients (45 bilateral and 19 unilateral) underwent surgery. A total of 102 operations were performed. Substantial improvements were observed in provocative maneuvers after surgery. Before surgery, 79.7% were involved in sports or playing musical instruments with repetitive overhead activity, and after surgery, 86.2% of these patients returned to their previous activity level. CONCLUSIONS: Few patients were successfully managed with nonoperative activity modification and physical therapy. In those requiring surgical intervention, first or cervical rib resection with scalenectomy using a supraclavicular approach provided resolution of symptoms with 86.2% of patients being able to return to presymptom sport or activity level. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Segmental Yttrium-90 Radioembolization Using Glass Microspheres Greater than 400 Gray for the Treatment of Intrahepatic Cholangiocarcinoma: A Preliminary Experience.

Radiation segmentectomy with a dose of >190 Gy using yttrium-90 (90Y) glass microspheres for intrahepatic cholangiocarcinoma (iCCA) has been shown to be safe and effective. The present study further increased the dose to >400 Gy for treatment of iCCA as complete pathologic necrosis has been shown in hepatocellular carcinoma using this ablative approach. A total of 10 patients with 13 tumors (median size, 5.3 cm; range, 1.5-13.6 cm) at a single institution underwent >400-Gy segmental radioembolization. Objective response was achieved in all tumors (13 of 13, 100%). One patient developed a Grade 3 or greater major adverse event (stroke and hepatic decompensation). One patient was bridged to transplant (>95% pathologic necrosis), whereas another underwent resection (>99% necrosis). Contralateral hypertrophy was observed in 6 out of 6 patients treated with modified lobectomy dosing, with a functional liver reserve increase from a median of 31.5% to 57.1%. The present report suggests that segmental transarterial radioembolization with >400 Gy is feasible in terms of safety and effectiveness for treating iCCA.

AAPM task group report 305: Guidance for standardization of vendor-neutral reject analysis in radiography.

Reject rate analysis is considered an integral part of a diagnostic radiography quality control (QC) program. A rejected image is a patient radiograph that was not presented to a radiologist for diagnosis and that contributes unnecessary radiation dose to the patient. Reject rates that are either too high or too low may suggest systemic department shortcomings in QC mechanisms. Due to the lack of standardization, reject data often cannot be easily compared between radiography systems from different vendors. The purpose of this report is to provide guidance to help standardize data elements that are required for comprehensive reject analysis and to propose data reporting and workflows to enable an effective and comprehensive reject rate monitoring program. Essential data elements, a proposed schema for classifying reject reasons, and workflow implementation options are recommended in this task group report.

Presentation and Management of the Pediatric Trigger Finger: A Multicenter Retrospective Cohort Study.

PURPOSE: Pediatric trigger finger (PTF) is an acquired condition that is uncommon and anatomically complex. Currently, the literature is characterized by a small number of retrospective case series with limited sample sizes. This investigation sought to evaluate the presentation, management, and treatment outcomes of PTF in a large, multicenter cohort. METHODS: A retrospective review of pediatric patients with a diagnosis of PTF between 2009 and 2020 was performed at three tertiary referral hospitals. Patient demographics, PTF characteristics, treatment strategies, and outcomes were abstracted from the electronic medical records. Patients and families also were contacted by telephone to assess the downstream persistence or recurrence of triggering symptoms. RESULTS: In total, 321 patients with 449 PTFs were included at a mean follow-up of 3.9 ± 4.0 years. There were approximately equal numbers of boys and girls, and the mean age of symptom onset was 5.4 ± 5.1 years. The middle (34.7%) and index (11.6%) fingers were the most and least commonly affected digits, respectively. Overall, PTFs managed operatively achieved significantly higher rates of complete resolution compared with PTFs managed nonsurgically (97.1% vs 30.0%). Seventy-five percent of PTFs that achieved complete resolution with nonsurgical management did so within 6 months, and approximately 90% did so within 12 months. Patients with multidigit involvement, higher Quinnell grade at presentation, or palpable nodularity were significantly more likely to undergo surgery. There was no significant difference in the rate of complete resolution between splinted versus not splinted PTFs or across operative techniques. CONCLUSIONS: Only 30% of the PTFs managed nonsurgically achieved complete resolution. Splinting did not improve resolution rates in children treated nonsurgically. In contrast, surgical intervention has a high likelihood of restoring motion and function of the affected digit. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

International Pediatric Multidisciplinary Management Using Telemedicine to Promote Equitable Care.

Objective: To evaluate the use of telemedicine as a collaboration tool between a pediatrician and subspecialists looking to address challenges, such as the lack of health care specialists, which are present in the Dominican Republic. Study design: During this 6-year study, 65 patients were evaluated by a medical team consisting of a local pediatrician and 17 subspecialists from a leading academic medical center in the Unites States. Patient's age ranged from 2 months to 16 years of age (mean 8 years old). The most common reasons for referral were masses or malignancies, vascular malformations, urogenital anomalies, stuttering, and cochlear implant programming. Results: A total of 39 out of 65 cases (60%) carried an initial diagnosis. Of the 65 cases, a change in medical management occurred in 92.31% of cases (60 cases). There was no change in medical diagnosis or treatment in 5 of 65 cases (8%). Conclusion: This protocol exhibited high patient satisfaction with the technology and platform and direct patient savings from transportation costs. It also demonstrated the importance of thorough diagnosis in providing appropriate treatment and solutions. Telemedicine use in comparable practices should be studied further to aid in the development of policies for the diagnosis and management of chronic illnesses that require referrals to subspecialists.

A hybrid Shewhart chart for visualizing and learning from epidemic data.

OBJECTIVE: As the globe endures the coronavirus disease 2019 (COVID-19) pandemic, we developed a hybrid Shewhart chart to visualize and learn from day-to-day variation in a variety of epidemic measures over time. CONTEXT: Countries and localities have reported daily data representing the progression of COVID-19 conditions and measures, with trajectories mapping along the classic epidemiological curve. Settings have experienced different patterns over time within the epidemic: pre-exponential growth, exponential growth, plateau or descent and/ or low counts after descent. Decision-makers need a reliable method for rapidly detecting transitions in epidemic measures, informing curtailment strategies and learning from actions taken. METHODS: We designed a hybrid Shewhart chart describing four 'epochs' ((i) pre-exponential growth, (ii) exponential growth, (iii) plateau or descent and (iv) stability after descent) of the COVID-19 epidemic that emerged by incorporating a C-chart and I-chart with a log-regression slope. We developed and tested the hybrid chart using international data at the country, regional and local levels with measures including cases, hospitalizations and deaths with guidance from local subject-matter experts. RESULTS: The hybrid chart effectively and rapidly signaled the occurrence of each of the four epochs. In the UK, a signal that COVID-19 deaths moved into exponential growth occurred on 17 September, 44 days prior to the announcement of a large-scale lockdown. In California, USA, signals detecting increases in COVID-19 cases at the county level were detected in December 2020 prior to statewide stay-at-home orders, with declines detected in the weeks following. In Ireland, in December 2020, the hybrid chart detected increases in COVID-19 cases, followed by hospitalizations, intensive care unit admissions and deaths. Following national restrictions in late December, a similar sequence of reductions in the measures was detected in January and February 2021. CONCLUSIONS: The Shewhart hybrid chart is a valuable tool for rapidly generating learning from data in close to real time. When used by subject-matter experts, the chart can guide actionable policy and local decision-making earlier than when action is likely to be taken without it.

Understanding variation in reported covid-19 deaths with a novel Shewhart chart application.

OBJECTIVE: Motivated by the coronavirus disease 2019 (covid-19) pandemic, we developed a novel Shewhart chart to visualize and learn from variation in reported deaths in an epidemic. CONTEXT: Without a method to understand if a day-to-day variation in outcomes may be attributed to meaningful signals of change-rather than variability we would expect-care providers, improvement leaders, policy-makers, and the public will struggle to recognize if epidemic conditions are improving. METHODS: We developed a novel hybrid C-chart and I-chart to detect within a geographic area the start and end of exponential growth in reported deaths. Reported deaths were the unit of analysis owing to erratic reporting of cases from variability in local testing strategies. We used simulation and case studies to assess chart performance and define technical parameters. This approach also applies to other critical measures related to a pandemic when high-quality data are available. CONCLUSIONS: The hybrid chart detected the start of exponential growth and identified early signals that the growth phase was ending. During a pandemic, timely reliable signals that an epidemic is waxing or waning may have mortal implications. This novel chart offers a practical tool, accessible to system leaders and frontline teams, to visualize and learn from daily reported deaths during an epidemic. Without Shewhart charts and, more broadly, a theory of variation in our epidemiological arsenal, we lack a scientific method for a real-time assessment of local conditions. Shewhart charts should become a standard method for learning from data in the context of a pandemic or epidemic.

Bizarre Parosteal Osteochondromatous Proliferation (Nora Lesion) in Pediatric Phalanges.

Bizarre parosteal osteochondromatous proliferation, or Nora tumor, is an uncommon lesion affecting the tubular bones of the hands and feet. Normally arising from the cortical surface and periosteum of these bones, these lesions histologically consist of a hypercellular cartilaginous cap covering a bony stalk that is surrounded by ossified areas and spindle cell stroma. The differential diagnosis includes conditions involving the periosteum such as chondrosarcoma, parosteal osteosarcoma, osteochondroma, turret exostosis, and florid reactive periostitis. The only effective treatment is wide surgical excision; nevertheless, local recurrence rates are extremely high and may necessitate revision surgery. In the present study, we report 3 cases of Nora lesion located in the hand in pediatric patients. The diagnosis in these cases was challenging owing to their presenting symptoms and radiographic findings. The diagnosis was made based on characteristic findings noted on the radiographic images and was confirmed by histological examination following excision.

SNAP/CLIP-Tags and Strain-Promoted Azide-Alkyne Cycloaddition (SPAAC)/Inverse Electron Demand Diels-Alder (IEDDA) for Intracellular Orthogonal/Bioorthogonal Labeling.

Labeling a protein of interest (POI) with a fluorescent reporter is a powerful strategy for studying protein structures and dynamics in their native environments. Compared to fluorescent proteins, synthetic dyes provide more choices in photophysical or photochemical attributes to microscopic characterizations. The specificity of bioorthogonal reactions in conjunction with the fidelity of subcellular destinations of genetically encoded protein tags can be employed to label POIs in live and fixed cells in a two-step process. In the present study the orthogonality of the strain-promoted azide-alkyne cycloaddition (SPAAC) and the inverse electron demand Diels-Alder (IEDDA) reaction is corroborated in concurrent labeling of two different intracellular targets. An azido group and a strained alkene are first installed at specific subcellular locations via orthogonal enzymatic reactions of the genetically incorporated SNAP- and CLIP-tags. The subsequent bioorthogonal reactions with fluorophores carrying matching reactive functionalities result in simultaneous dual labeling. The two-step "orthogonal-bioorthogonal" labeling process would increase the utilities of SNAP/CLIP-tags and, as a consequence, would expand the capability of decorating biological specimens with functionalities beyond fluorophores to potentially include spin labels, radioactive tracers, or catalysts.

Improvement in MR quality control workflow and outcomes with a web-based database.

PURPOSE: To describe a custom-built, web-based MR Quality Control (QC) database, and to assess its impact on the QC workflow and outcomes in a large U.S. academic medical center. METHODS: The MR QC database was built with Microsoft Access 2010 and published on a Microsoft Sharepoint website owned and maintained by the authors' institution. Authorized users can access the database remotely with mainstream web browsers on any institutional computers. QC technologists were granted access to add, review, and print daily and weekly QC records. Qualified medical physicists (QMPs) were granted additional access to edit, review, and approve existing QC records and to change tolerance limits. A macro was utilized to conduct an automatic weekly review of QC status and to email the results to a QMP. This web-based QC database was implemented on 17 clinical MRIs at the authors' institution. Weekly ACR QC findings within one year before and after implementation were compared. RESULTS: We analyzed 158 QC issues detected by the web-based database and 127 QC issues identified in conventional paper records before we implemented the database. The web-based database significantly reduced the number of QC issues due to technologist error (before/after: 59/24 cases, P < 0.0001) but did not affect the number of QC issues related to scanner performance (before/after: 49/46 cases, P = 1). Further analysis revealed that the web-based database significantly reduced the average time for the QMPs to identify a QC issue (before/after: 177 ± 110/2 ± 2 days, P < 0.0001) and time to correction (before/after: 81 ± 102/7 ± 8 days, P < 0.0001). The correction rate also significantly increased (before/after: 22%/99%, P < 0.0001). CONCLUSION: The web-based QC database provides a positive impact on our MR QC workflow and outcomes. It simplifies QC workflow, enables early detection of quality issues, and facilitates quick resolution of problems that may affect the quality of clinical MRI studies.

Humerus Rotation Has a Negligible Effect on Baumann Angle in a Wide Range of Rotational Positions.

BACKGROUND: Rotation of the humerus out of the coronal plane is presumed to alter the Baumann angle (BA) value. Identifying the rotational limits of the humerus at which the BA can be accurately and reliably measured will circumvent repeated radiographs and unnecessary exposure to radiation, may improve patient comfort, and save time and medical resources. METHODS: A retrospective chart review was performed to identify patients under the age of 18 who underwent an elbow computed tomography (CT) scan without any humeral pathology and with an open distal humeral physis. For each patient, a 3-dimensional (3D) computerized model was generated with 30% transparency to mimic a plain radiograph. These models were rotated in 10-degree increments and the BA was measured on each position. In addition, the measurements were taken on an anteroposterior radiograph for each patient. Analysis of variance and the Pearson tests were performed to locate differences and define associations. RESULTS: Fifteen 3D CT reconstructions were generated from 14 patients. The mean BA on the neutral position was found to be 72.2±3 degrees, which correlated with the 70.6±5.91 degrees measurement obtained on radiographs. The most extreme rotational positions on which the BA values were consistent with the neutral position values were +40 external rotation (70.97±7.01 degrees, P=1) and -70 degrees internal rotation (68.4±7.47 degrees, P=0.14). A negative correlation was found between the BA values and the extent at which the humerus was rotated from the neutral position. The variability of the BA between patients, implied by the SD of measurements on each position increased with increasing rotation from the neutral position (r=1, P<0.05). CONCLUSIONS: On the basis of 3D CT images, the BA is the most accurate when the arm is positioned at an exact anteroposterior position. It is reliable to measure the BA when the humerus is rotated no more than +40 degrees external rotation to -70 degrees internal rotation. This range of rotation can act as an "accurate zone" and help avoiding multiple radiographs. LEVEL OF EVIDENCE: Level III.

Performance of a Deep Neural Network Algorithm Based on a Small Medical Image Dataset: Incremental Impact of 3D-to-2D Reformation Combined with Novel Data Augmentation, Photometric Conversion, or Transfer Learning.

Collecting and curating large medical-image datasets for deep neural network (DNN) algorithm development is typically difficult and resource-intensive. While transfer learning (TL) decreases reliance on large data collections, current TL implementations are tailored to two-dimensional (2D) datasets, limiting applicability to volumetric imaging (e.g., computed tomography). Targeting performance enhancement of a DNN algorithm based on a small image dataset, we assessed incremental impact of 3D-to-2D projection methods, one supporting novel data augmentation (DA); photometric grayscale-to-color conversion (GCC); and/or TL on training of an algorithm from a small coronary computed tomography angiography (CCTA) dataset (200 examinations, 50% with atherosclerosis and 50% atherosclerosis-free) producing 245 diseased and 1127 normal coronary arteries/branches. Volumetric CCTA data was converted to a 2D format creating both an Aggregate Projection View (APV) and a Mosaic Projection View (MPV), supporting DA per vessel; both grayscale and color-mapped versions of each view were also obtained. Training was performed both without and with TL, and algorithm performance of all permutations was compared using area under the receiver operating characteristics curve. Without TL, APV performance was 0.74 and 0.87 on grayscale and color images, respectively, compared to 0.90 and 0.87 for MPV. With TL, APV performance was 0.78 and 0.88 on grayscale and color images, respectively, compared with 0.93 and 0.91 for MPV. In conclusion, TL enhances performance of a DNN algorithm from a small volumetric dataset after proposed 3D-to-2D reformatting, but additive gain is achieved with application of either GCC to APV or the proposed novel MPV technique for DA.

Outcomes of Spinal Accessory-to-Suprascapular Nerve Transfers for Brachial Plexus Birth Injury.

PURPOSE: The results of a spinal accessory nerve-to-suprascapular (SAN-SSN) nerve transfer for brachial plexus birth injuries (BPBIs) have thus far been presented only in limited case series. Our study evaluates the recovery of shoulder function of patients who underwent an SAN-SSN for BPBI as an isolated procedure or as part of a multinerve reconstruction (MNR) surgery. METHODS: We retrospectively reviewed the medical records of patients at a single institution who underwent an SAN-SSN after BPBI. Inclusion criteria were patients with both preoperative and a minimum 12-months postoperative active movement scale (AMS) scores. Patients for whom the primary surgery involved tendon transfers were excluded. The primary outcome measures were AMS scores for shoulder abduction, forward flexion, and external rotation and secondary outcomes included the need for further shoulder surgery to improve function. RESULTS: Seventy-three patients met the inclusion criteria. Forty-three patients (58.9%) obtained functional shoulder motion (AMS ≥ 6) of at least 1 of 3 planes (abduction/flexion/external rotation) following surgery, with 13 patients (17.8%) achieving full recovery of 1 of these shoulder motions against gravity (AMS = 7). Fifty-six patients (76.7%) did not undergo subsequent tendon transfers or corrective osteotomies to augment shoulder function. The MNR procedures were performed in 46 patients (63%), of whom 45.7% gained a functional recovery. In 27 patients for whom SAN-SSN nerve transfer was conducted in isolation, 81.5% gained functional shoulder motion. However, isolated SAN-SSNs were conducted at a later age than MNR procedures (13.2 vs 4.8 months) and had higher preoperative AMS scores. The anterior and posterior approaches for SAN-SSN were both found to be effective when used for SAN-SSN in BPBI. When the follow-up duration cutoff was set to 3 years, the outcomes were found to be superior. CONCLUSIONS: In 76.7% of the patients, SAN-SSN was able to recover function that was sufficient to prevent tendon transfers and corrective osteotomies. A cutoff of 3 postoperative years should be used as a benchmark for analyzing the results of this procedure. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

A Bundled Payment Model for Pediatric Distal Radius Fractures: Defining an Episode of Care.

BACKGROUND: Distal radius fractures are the most common fracture of childhood, occurring in ∼1 per 100 children annually. Given the high incidence of these fractures, we explored feasibility of a bundled payment model. We determined the total treatment costs for each child and identified components of fracture management that contributed to variations in cost. METHODS: We retrospectively reviewed all hospital and physician costs related to the treatment of closed distal radius fractures at a large academic children's hospital. We included all children age 2 to 15 years treated by an orthopaedic surgeon for an isolated closed distal radius fracture between 2013 and 2015. We compared total treatment costs by fracture management approach. We then estimated the contribution of each component of fracture management to total treatment costs using linear regression. RESULTS: We identified 5640 children meeting the inclusion criteria, of which 4602 (81.6%) received closed treatment without manipulation, 922 (16.3%) underwent closed reduction in the clinic, emergency department, or radiology procedure suite, and 116 (2.1%) underwent treatment in the operating room. The median cost for closed treatment without manipulation was $1390 [interquartile range (IQR) 1029 to 1801], compared with $4263 (IQR, 3740 to 4832) for closed reduction and $9389 (IQR, 8272 to 11,119) for closed reduction and percutaneous pinning (P<0.001). In multivariable regression analysis, fracture management approach and use of the operating room environment were the largest cost drivers (P<0.001, R=0.88). Closed reduction in the clinic or emergency department added $894 (95% confidence interval, 819-969) to treatment costs, while closed reduction in the operating room added $5568 (95% confidence interval, 5224-6297). Location of the initial clinical evaluation, number of radiographic imaging series obtained, and number of orthopaedic clinic visits also contributed to total costs. CONCLUSIONS: Closed pediatric distal radius fractures treated without manipulation show small variations in treatment costs, making them well suited for bundled payment. Bundled payments for these fractures could reduce costs by encouraging adoption of existing evidence-based practices. LEVEL OF EVIDENCE: Level III-therapeutic.

Increasing Brace Treatment for Pediatric Distal Radius Buckle Fractures: Using Quality Improvement Methodology to Implement Evidence-based Medicine.

BACKGROUND: Multiple randomized trials have showed equivalent outcomes and improved patient/family satisfaction using a removable brace to treat pediatric distal radius buckle fractures (DRBF). We tested the hypothesis that we could use quality improvement (QI) methodology to increase the proportion of patients with DRBF treated with removable braces at 2 tertiary care orthopaedic clinics from a baseline of 34.8% to 80%. METHODS: Clinic billing records were reviewed monthly to determine treatment (brace vs. cast) of DRBF and tracked using control charts (p-chart). Balance measures including correct application of the diagnostic criteria and algorithm were monitored. Process measures including the number of follow-up visits, radiographs obtained, and total cost of treatment were collected. Baseline data were obtained over a 3-month period, followed by a 12-month period of interventions using Plan-Do-Study-Act cycles targeting both individuals and groups of providers. RESULTS: The proportion of DRBF treated in a brace increased from a combined baseline of 34.8% to a combined 84% at the end of the study period. Following intervention, 83% (15/18) of providers began using braces for a majority of patients (defined as >67%), with only 1 provider continuing to use casts 100% of the time. Patient preference was cited as the most common reason for use of cast treatment. There was a significant decrease in the number of radiographs obtained at 1 of 2 institutions. The charges for brace treatment averaged $630 less per patient than for cast treatment, leading to an estimated medical-cost savings of $205,000 following intervention. CONCLUSIONS: Implementation of brace treatment for pediatric DRBF using QI methodology resulted in a shift toward brace treatment in the majority of patients, leading to substantial medical and nonmedical cost savings. Although patient preference was cited as the most common reason for persistent cast treatment, the data show the use of cast treatment to be more dependent upon individual provider preference. LEVEL OF EVIDENCE: Level II-therapeutic.

Investigating small molecules to inhibit germinal center kinase-like kinase (GLK/MAP4K3) upstream of PKCθ phosphorylation: Potential therapy to modulate T cell dependent immunity.

Germinal center kinase-like kinase (GLK, also known as MAP4K3) has been hypothesized to have an effect on key cellular activities, including inflammatory responses. GLK is required for activation of protein kinase C-θ (PKCθ) in T cells. Controlling the activity of T helper cell responses could be valuable for the treatment of autoimmune diseases. This approach circumvents previous unsuccessful approaches to target PKCθ directly. The use of structure based drug design, aided by the first crystal structure of GLK, led to the discovery of several inhibitors that demonstrate potent inhibition of GLK biochemically and in relevant cell lines.

Shielding a high-sensitivity digital detector from electromagnetic interference.

PURPOSE: To document a study in shielding a high-sensitivity digital mammography system detector from AC magnetic fields of magnitudes great enough to induce imaging artifacts. METHODS/MATERIALS: Preliminary evaluation of AC magnetic fields at a site designated for a digital breast tomosynthesis (DBT) system raised concerns that the magnetic component of electromagnetic interference (EMI) may be great enough to induce imaging artifacts. Subsequent measurements using digital detector arrays from two separate manufacturers verified this concern, and AC magnetic fields were mapped, spatially and temporally, throughout the area of concern. A simple shielding model was developed to elucidate the physics of extremely low-frequency (ELF) EMI shielding and independently verify a commercial group's proposed shielding design and installation. Postshielding measurements were performed to demonstrate that the EMI fields were reduced to acceptable levels. RESULTS: Preshielding measurements showed AC magnetic fields significantly exceeding manufacturers' tolerances for artifact-free imaging in DBT. Continuous measurements demonstrated that the EMI fields varied significantly over time. Some locations in the room routinely averaged above 30 mG and occasionally exceeded 100 mG. The source was attributed to an adjacent electrical supply room, and temporal changes of the EMI were attributed to variations of the building electrical loads. The proposed shielding primarily consisted of continuous aluminum (6.35 mm thickness) and was installed by a group specializing in electromagnetic field shielding. Postshielding measurements demonstrated that the EMI fields were significantly reduced, generally to less than 0.5 mG, and that the shielding effectively dampened the large variations due to dynamic building electrical loads. Subsequent installation and evaluation of a DBT system revealed no issues with imaging artifacts. CONCLUSIONS: The successful shielding of ELF EMI involves physical principles that are not commonly encountered by medical physicists. Modern high-sensitivity digital detectors may be successfully shielded against imaging artifacts with careful application of these principles.

Outcomes of Isolated Radial Osteotomy for Volar Distal Radioulnar Joint Instability Following Radial Malunion in Children.

PURPOSE: The radius bone has a slight dorsoradial bow that allows for full forearm pronosupination around the ulna. However, radial malunion can lead to reversal of the radial bow and subsequent volar instability of the distal radioulnar joint (DRUJ), predominantly in supination. This study assessed the outcomes of corrective radial osteotomy for volar DRUJ instability after radial malunion in children. METHODS: The charts of 7 children (2 boys and 5 girls) treated with corrective radial osteotomy for volar DRUJ instability after a radius fracture or deformity were reviewed. Demographic, diagnostic, treatment, and complication information was collected for each patient. Radiographs at initial injury, fracture union, diagnosis of DRUJ instability, and final follow-up were reviewed for radiographic measurements of radial deformity and subsequent correction. RESULTS: Fractures included 4 distal radius, 2 proximal radius, and 1 plastic deformation of the radial shaft. Volar DRUJ instability was diagnosed an average of 2.7 years (range, 1-6 years) after fracture at an average age of 13.6 years (range, 12-17 years). Two of 7 patients had persistent symptoms despite having undergone previous soft tissue surgery for DRUJ instability. Radial osteotomy was performed on all patients (3 dorsal and 4 volar approaches), with an average sagittal plane correction of 23° ± 10° (range, 14° to 40°). Osteotomy site varied (3 proximal third, 1 middle third, and 3 distal third) based on the apex of maximal deformity. Patients were observed an average of 2.3 years (range, 1.0-5.7 years). At final follow-up, all patients had a stable DRUJ and no patient required soft tissue stabilization. CONCLUSIONS: Apex volar malunion of radial fractures may result in volar instability of the DRUJ. Radial osteotomy restored the normal apex dorsal radial bow and effectively stabilized the DRUJ without the need for soft tissue repair. Osteotomy should be tailored to the specific site of radiographic deformity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Radiology and Enterprise Medical Imaging Extensions (REMIX).

Radiology and Enterprise Medical Imaging Extensions (REMIX) is a platform originally designed to both support the medical imaging-driven clinical and clinical research operational needs of Department of Radiology of The Ohio State University Wexner Medical Center. REMIX accommodates the storage and handling of "big imaging data," as needed for large multi-disciplinary cancer-focused programs. The evolving REMIX platform contains an array of integrated tools/software packages for the following: (1) server and storage management; (2) image reconstruction; (3) digital pathology; (4) de-identification; (5) business intelligence; (6) texture analysis; and (7) artificial intelligence. These capabilities, along with documentation and guidance, explaining how to interact with a commercial system (e.g., PACS, EHR, commercial database) that currently exists in clinical environments, are to be made freely available.

Automated Critical Test Findings Identification and Online Notification System Using Artificial Intelligence in Imaging.

Purpose To evaluate the performance of an artificial intelligence (AI) tool using a deep learning algorithm for detecting hemorrhage, mass effect, or hydrocephalus (HMH) at non-contrast material-enhanced head computed tomographic (CT) examinations and to determine algorithm performance for detection of suspected acute infarct (SAI). Materials and Methods This HIPAA-compliant retrospective study was completed after institutional review board approval. A training and validation dataset of noncontrast-enhanced head CT examinations that comprised 100 examinations of HMH, 22 of SAI, and 124 of noncritical findings was obtained resulting in 2583 representative images. Examinations were processed by using a convolutional neural network (deep learning) using two different window and level configurations (brain window and stroke window). AI algorithm performance was tested on a separate dataset containing 50 examinations with HMH findings, 15 with SAI findings, and 35 with noncritical findings. Results Final algorithm performance for HMH showed 90% (45 of 50) sensitivity (95% confidence interval [CI]: 78%, 97%) and 85% (68 of 80) specificity (95% CI: 76%, 92%), with area under the receiver operating characteristic curve (AUC) of 0.91 with the brain window. For SAI, the best performance was achieved with the stroke window showing 62% (13 of 21) sensitivity (95% CI: 38%, 82%) and 96% (27 of 28) specificity (95% CI: 82%, 100%), with AUC of 0.81. Conclusion AI using deep learning demonstrates promise for detecting critical findings at noncontrast-enhanced head CT. A dedicated algorithm was required to detect SAI. Detection of SAI showed lower sensitivity in comparison to detection of HMH, but showed reasonable performance. Findings support further investigation of the algorithm in a controlled and prospective clinical setting to determine whether it can independently screen noncontrast-enhanced head CT examinations and notify the interpreting radiologist of critical findings. © RSNA, 2017 Online supplemental material is available for this article.