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Musculoskeletal neoplasms include tumors arising from bone, cartilage, muscles, tendons, nerves, and synovium. After initial screening radiographs, magnetic resonance (MR) imaging is the mainstay of management, and its role continues to increase in both pre- and post-operative evaluations. This article presents a review of the available qualitative and quantitative MR techniques for evaluating musculoskeletal neoplasms, including conventional and advanced imaging techniques such as diffusion-weighted and diffusion-tensor imaging, chemical shift and Dixon imaging, dynamic contrast-enhanced MRI, neurography, and spectroscopy. After reading the article, radiologists and oncologists will be able to apply these principles in their practices to benefit patients with musculoskeletal neoplasms.

Operative management displaced intra-articular calcaneus fractures is commonly associated with wound complications. Open reduction internal fixation is traditionally performed through the extensile lateral approach has relatively high rates of wound complications. The sinus tarsi approach to displaced intra-articular calcaneus fractures is a less invasive approach to achieve fracture reduction and fixation as well as reduce wound healing complications. The purpose of this study is to report the rates of wound complications associated with the sinus tarsi approach in the treatment of displaced intra-articular calcaneus fractures.We retrospectively identified patients treated with a limited sinus tarsi approach for displaced intra-articular calcaneus fractures from January 2009 to December 2018. Demographic and radiographic data were collected including age, gender, mechanism of injury, occupation, presence of diabetes mellitus, smoking status, Sanders classification, Bohler and Gissane angles. Postoperatively, we recorded the presence of complications, return-to-work time, and radiographic measurements.One hundred and five fractures were identified in 100 patients who underwent open reduction internal fixation for displaced intra-articular calcaneus fractures. Using the Sanders computed tomographic classification, we identified 32% Type 2, 48% Type 3, 18% Type 4, and 2% tongue-type variants. For the preoperative Bohler's angle, 38% of fractures displayed a negative angle, 50% had an angle 0° to 20°, and 12% over 20°. Postoperatively, all patients demonstrated an improvement in Bohler's angle with 13% with 0° to 20° and 87% over 20°. Approximately, 72% of patients working prior to the injury had returned to work by 6 months, and 89% by 12 months. The wound complication rate was 11.9% (12/105), with 1.9% (2/105) requiring additional procedures. There was no significant difference in wound complication rates in smokers versus nonsmokers (11.9% vs 12.2%, p = .55).Operative management of displaced intra-articular calcaneus fractures through the sinus tarsi approach allows restoration of calcaneal height with a low rate of wound complications, even among active smokers.

ACL reconstruction tunnel location is an important predictor for outcomes after surgery. The aim was to establish 3D and 2D MRI radiological measurements for native ACL tibial footprint that can provide information to facilitate pre-operative planning for anatomical graft placement. The measurements were also correlated in a subset of patients on arthroscopy.Retrospective evaluation of a consecutive series of knee MRIs with both 2D and 3D MR imaging was performed in 101 patients with 43 men and 66 women and ages 39.5 ± 11.9 years. Two measurements were obtained, tibial to ACL and intermeniscal ligament to ACL (T-ACL) and (IM-ACL), respectively. In a cohort of 18 patients who underwent knee arthroscopy, the T-ACL and IML-ACL distances were also determined by an orthopedic surgeon using a standard scale. ICC, Pearson correlation, and Bland-Altman plot were generated.For readers 1 and 2, the mean differences between 2D and 3D measurements of T-ACL and IM-ACL were 1.17 and 1.03 mm and 0.65 and 0.65 mm, respectively. The 2D measurements of T-ACL and IM-ACL were larger than the 3D measurements for both readers. The inter-reader reliability was excellent on 2D (0.81-0.96) and fair to excellent on 3D MRI (0.59-0.90). The mean arthroscopic IML-ACL was closer to that of 3D MRI compared to 2D MRI. The mean arthroscopic T-ACL was closer to 2D MRI than 3D MRI.Both 2D and 3D MRI show inter-reader reliability with small inter-modality mean differences in the measurements from the tibial or inter-meniscal ligament margins.• The mean differences between 2D and 3D measurements of tibia-ACL and intermeniscal ligament-ACL are small (1.2 mm). • As compared to arthroscopy, the mean T-ACL and IML-ACL were closer to measurements from 2D and 3D MRI, respectively. • Both 2D and 3D MRI can be reliably used to delineate ACL foot plate anatomy.

Fascicular targeting of longitudinal intrafascicular electrode (FAST-LIFE) interface enables hand dexterity with exogenous electrical microstimulation for sensory restoration, custom neural recording hardware, and deep learning-based artificial intelligence for motor intent decoding. The purpose of this technical report from a prospective pilot study was to illustrate magnetic resonance neurography (MRN) mapping of hand and nerve anatomy in amputees and incremental value of MRN over electrophysiology findings in pre-surgical planning of FAST-LIFE interface (robotic hand) patients.After obtaining informed consent, patients with upper extremity amputations underwent pre-operative 3-T MRN, X-rays, and electrophysiology. MRN findings were correlated with electrophysiology reports. Descriptive statistics were performed.Five patients of ages 21-59 years exhibited 3/5 partial hand amputations, and 2/5 transradial amputations on X-rays. The median and ulnar nerve end bulb neuromas measured 10.1 ± 3.04 mm (range: 5.5-14 mm, median: 10.5 mm) and 10.9 ± 7.64 mm (2-22 mm, 9.75 mm), respectively. The ADC of median and ulnar nerves were increased at 1.64 ± 0.1 × 103-T MRN allows excellent demonstration of forearm and hand nerve anatomy, altered diffusion characteristics, and their neuromas despite unremarkable electrophysiology for pre-surgical planning of the FAST-LIFE (robotic hand) interfaces.

Scoliosis is a common orthopedic problem in patients with neurofibromatosis 1 (NF1). Spinal deformities are found in 77% of all NF1 cases, with no widely accepted etiology. This study aimed to evaluate the frequency and types of scoliosis in NF1 patients using whole-body magnetic resonance imaging and to assess the association of intraspinal and paraspinal tumors with the imaging findings of scoliosis.A total of 122 NF1 patients with whole-body magnetic resonance imaging were found from the electronic medical records. Ninety-seven cases that met the inclusion criteria were identified. All patients underwent 3-T magnetic resonance imaging with automated software fusion of the 3 sets of short TI inversion recovery and 3-dimensional T1-weighted coronal images. Frequency and location of scoliosis and intraspinal and paraspinal tumors were recorded. Patients with severe dystrophic-type scoliosis were separately identified, and Cobb angles were measured for all such cases. Association analysis was performed. A P value less than 0.05 was considered statistically significant.Ninety-seven patients with NF1 were evaluated. Two had prior spinal surgery and were excluded. The final sample of 95 patients included 33 (35%) men and 62 (65%) women with a mean ± SD body mass index of 25.82 (4.96) kg/m2. Of the 95 patients, 43 (45.3%) had scoliosis, 13 of 43 (30.2%) of which were severely angled. Of the 95 patients, 25 (26.3%) had locoregional tumor presence. Intraclass correlation for Cobb angles measured 0.99 (confidence interval, 0.98-1.0). Fisher exact test determined no association between scoliosis and presence of either paraspinal or intraspinal tumors (P = 0.485). There was also no association between the tumors and severe dystrophic scoliosis (P = 1.0).This study found no association between the presence of locoregional spinal tumors and scoliosis in NF1 patients. This work adds to the body of knowledge of scoliosis in NF1 patients and infers that presence of scoliosis should not mandate immediate search for locoregional spinal tumors.

Dual energy CT (DECT) is becoming increasingly popular and valuable in the domain of musculoskeletal imaging. Gout maps and crystal detection have been predominant indications for about a decade. Other important indications of bone marrow maps and metal artifact reduction are also frequent with added advantages of detection and characterization of bone marrow lesions similar to MR imaging and diagnosis of hardware related complications, respectively. This article discusses technical considerations and physics of DECT imaging and its role in musculoskeletal indications apart from crystal imaging with respective case examples and review of the related literature. DECT pitfalls in these domains are also highlighted and the reader can gain knowledge of above concepts for prudent use of DECT in their musculoskeletal and general practices.

Background Data describing the effect of obesity on antitumor necrosis factor (anti-TNF) treatment response are inconsistent. Visceral adipose tissue (VAT) is a superior marker of adiposity to body mass index. However, its effect on treatment response is unclear. We aimed to evaluate the effect of VAT on anti-TNF treatment response. Methods Inflammatory bowel disease (IBD) patients starting anti-TNF agents between January 1, 2009, and July 31, 2019, were included. 3-dimensional measurements of VAT volume and visceral fat index (visceral:subcutaneous adipose tissue ratio; VFI) were obtained from computed tomography (CT) scans. Subjects were categorized by predefined volume cutoffs ( Results The final cohort included 176 patients. No significant differences in treatment response at 6 months was observed. At 12 months, compared with volume Conclusions We found VAT volume is associated with anti-TNF treatment response in a nondose dependent manner, and VFI may inform risk of surgery after anti-TNF initiation. If confirmed by prospective studies, VAT volumetrics are potentially useful biomarkers to inform IBD treatment decisions.

Aims Pelvic tilt is believed to affect the symptomology of osteoarthritis (OA) of the hip by alterations in joint movement, dysplasia of the hip by modification of acetabular cover, and femoroacetabular impingement by influencing the impingement-free range of motion. While the apparent role of pelvic tilt in hip pathology has been reported, the exact effects of many forms of treatment on pelvic tilt are unknown. The primary aim of this study was to investigate the effects of surgery on pelvic tilt in these three groups of patients. Methods The demographic, radiological, and outcome data for all patients operated on by the senior author between October 2016 and January 2020 were identified from a prospective registry, and all those who underwent surgery with a primary diagnosis of OA, dysplasia, or femoroacetabular impingement were considered for inclusion. Pelvic tilt was assessed on anteroposterior (AP) standing radiographs using the pre- and postoperative pubic symphysis to sacroiliac joint (PS-SI) distance, and the outcomes were assessed with the Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and Harris Hip Score (HHS). Results The linear regression model revealed a significant negative predictive association between the standing pre- and postoperative PS-SI distances for all three groups of patients (all p < 0.001). There was a significant improvement in all three outcome measures between the pre- and postoperative values (p < 0.05). Conclusion There is a statistically significant decrease in pelvic tilt after surgery in patients with OA of the hip, dysplasia, and femoroacetabular impingement. These results confirm that surgery significantly alters the pelvic orientation. Pelvic tilt significantly decreased after total hip arthroplasty, periacetabular osteotomy, and arthroscopy/surgical hip dislocation. The impact of surgery on pelvic tilt should be considered within the therapeutic plan in order to optimize pelvic orientation in these patients. Cite this article: Bone Joint J 2022;104-B(9):1025–1031.

The Society of Skeletal Radiology (SSR) Practice Guidelines and Technical Standards Committee identified musculoskeletal infection as a White Paper topic, and selected a Committee, tasked with developing a consensus on nomenclature for MRI of musculoskeletal infection outside the spine. The objective of the White Paper was to critically assess the literature and propose standardized terminology for imaging findings of infection on MRI, in order to improve both communication with clinical colleagues and patient care.A definition was proposed for each term; debate followed, and the committee reached consensus. Potential controversies were raised, with formulated recommendations. The committee arrived at consensus definitions for cellulitis, soft tissue abscess, and necrotizing infection, while discouraging the nonspecific term phlegmon. For bone infection, the term osteitis is not useful; the panel recommends using terms that describe the likelihood of osteomyelitis in cases where definitive signal changes are lacking. The work was presented virtually to SSR members, who had the opportunity for review and modification prior to submission for publication.

Magnetic resonance imaging (MRI) is a common choice among various imaging modalities for the evaluation of hip conditions. Conventional MRI with two-dimensional acquisitions requires a significant amount of time and is limited by partial-volume artifacts and suboptimal fluid-to-cartilage contrast. Recent hardware and software advances have resulted in development of novel isotropic three-dimensional (3D) single-acquisition protocols that cover the volume of the entire hip and can be reconstructed in arbitrary planes for submillimeter assessment of bony and labro-cartilaginous structures in their planes of orientation. This technique facilitates superior identification of small labral tears and other hip lesions with better correlations with arthroscopy. In this review, we discuss technical details related to 3D MRI of the hip, its advantages, and its role in commonly encountered painful conditions that can be evaluated with great precision using this technology. The entities described are femoroacetabular impingement with acetabular labral tears, acetabular dysplasia, avascular necrosis, regional tendinopathies and tendon tears, bursitis, and other conditions.

The purpose of this study was to assess the intra- and inter-reader reliability of the 2 Charcot neuroarthropathy classifications (Sanders-Frykberg and Brodsky-Trepman), as well as Eichenholtz staging. We hypothesized that the inter-reader reliability, with respect to these 3 classification systems, would be moderate at best. Digital radiographic images were organized in a digital slide presentation without clinical information. All 5 reviewers underwent a standard training session administered by the principal investigator, reviewing 5 cases of Charcot neuroarthropathy. Images of 55 cases of Charcot neuroarthropathy and 5 normal cases were distributed to each of the 5 physicians electronically, who independently rated all 60 cases according to the 3 classification systems. The 95% confidence interval of the intraclass correlation coefficient estimate for Sanders-Frykberg was 0.9601 to 0.9833 at week 0 and 0.9579 to 0.9814 at week 8, which can be regarded as "excellent" reliability. For Trepman-Brodsky, the 95% confidence interval of the intraclass correlation coefficient estimate was 0.8463 to 0.9327 at week 0 and 0.8129 to 0.9226 at week 8, which can be regarded as "good" to "excellent" reliability. For Eichenholtz, the 95% confidence interval of the intraclass correlation coefficient estimate was 0.6841 to 0.8640 and 0.6931 to 0.8730 at weeks 0 and 8, respectively, which can be regarded as "moderate" to "good" reliability. The classification systems of Charcot neuroarthropathy are an important tool for communication among physicians. Based on the results at our institution, the Sanders-Frykberg classification exhibited the best inter-reader performance. The Trepman-Brodsky classification exhibited good to excellent reliability as well. The intraclass correlation coefficient of the Eichenholtz classification was moderate to good.

Hallux valgus is a complex deformity with a variety of techniques described for correction. A biplanar plating system for triplanar correction system has been developed to address both the translation and rotational component of the hallux valgus deformity and allow an accelerated weightbearing protocol. The purpose of this study was to determine the correction and complications using radiographic parameters and patient reported outcomes. We sought to determine prognostic factors for successful correction, including age, gender, and preoperative deformity. From the medical records, we collected preoperative data. Patient-reported outcomes were obtained using AOFAS Hallux Metatarsophalangeal-Interphalangeal score, FAAM, and SF-12 scores preoperatively and postoperatively. Imaging was reviewed at preoperative and postoperative visits to determine hallux valgus angle, intermetatarsal angle, and tibial sesamoid position. Fifty-seven procedures, in 55 patients, were performed. There were 7 complications and mean follow-up time was 45.7 weeks (+ 28.3 weeks). Age over 62.5 years were associated with an increased risk of complications (p = .018). Males had an increased rate of complications (71%) compared with females. Radiographic parameters were significantly improved from preoperative values at alltime points (p.05). Only the AOFAS Hallux Metatarsophalangeal-Interphalangeal score was statistically significant at 3, 6 and 12 months. We sought to determine the effectiveness of biplanar plating and triplanar correction procedure with early weightbearing. Over a 12 month follow-up period, our results showed significant improvement in deformity and maintained correction. AOFAS Hallux Metatarsophalangeal-Interphalangeal scores significantly improved from the preoperative to the postoperative state. Our results show a nonunion rate of 5.2%, which is comparable to prior studies.

PURPOSE: We assessed the prevalence of low bone mineral density (BMD) in oncologic patients undergoing F-18-FDG-PET/CT. MATERIALS AND METHODS: Retrospective analysis of 100 patients who underwent F-18-FDG-PET/CT at a single center from October 2015 till May 2016. Quantitative computed tomography (QCT) was used to assess BMD at the lumbar spine (BMD(QCT)) and femoral necks (BMD(CTXA)). SUV(max) was used to evaluate metabolic activity of the bone marrow. Risk of osteoporosis-related fractures was calculated with femoral neck BMD(CTXA) and the FRAX® algorithm, which was compared against measurements of CT attenuation of the trabecular bone at L1 (L1(HU)). RESULTS: Osteoporosis/osteopenia were respectively present in 16%/46% of patients ≥ 50 years old. Bone marrow SUV(max) was correlated with BMD at the lumbar spine (ρ=0.36, p

This is an invited editorial on radiologist burnout, its presenting manifestations, toll on patient care and systems-based practice, and suggested remedies to mitigate stress and exhaustion.

The aims of the study were to systematically evaluate the sacroiliac joints of a consecutive series of patients with clinically suspected axial spondyloarthritis and to compare the diagnostic efficacy of 3-dimensional (3D) imaging versus conventional multisequence 2D techniques for sacroiliitis.In this cross-sectional multireader validation study, imaging studies of 104 consecutive patients with clinically suspected axial spondyloarthritis obtained with a rheumatology lumbosacral magnetic resonance imaging protocol were evaluated. Three-dimensional coronal oblique reconstructions parallel to the long axis of the sacrum were created. Two blinded readers evaluated 2D and 3D images separately for each study, and findings were compared with the reference standard for the final diagnosis and disease activity. Cohen κ and diagnostic performance measures on 2D and 3D imaging were evaluated and compared.With 2D versus 3D imaging, respectively, the sensitivity for detecting inflammatory cases was 57% versus 62% ( P = 0.1007), the sensitivity for detecting mechanical cases was 89% versus 76% ( P = 0.0312), the sensitivity for detecting active sacroiliitis was 49% versus 64% ( P = 0.0014), and the specificity for detecting active sacroiliitis was 87% versus 76% ( P = 0.0016). Interreader agreement of 2D imaging showed an overall range of κ = 0.27-0.85, and it was best for evaluation of bony ankylosis (κ = 0.85). Interreader agreement of 3D imaging was in an overall range of κ = 0.15-0.64.Single 3D isotropic magnetic resonance imaging provided adequate assessment of sacroiliac joints in this study and demonstrated significantly higher sensitivity and lower specificity for detecting active sacroiliitis. The initial results indicate that 3D imaging could be used for future works for screening sacroiliitis and abdominopelvic enthesopathy.

Purpose Acetabular dysplasia (AD) is a debilitating condition which results in impaired hip function, leading to hip-spine syndrome with anomalies identifiable on plain radiographs. However, no study to date has investigated the association between radiographic spine anomalies and functional outcomes in AD. We hypothesize that AD patients with radiographic evidence of lumbar spine anomalies are associated with decreased function in comparison to those without such radiographic findings. Patients and methods One hundred thirty-five hips underwent a full four-view hip radiograph series, and two observers analyzed hip and spine variables using standard radiographs and obtained Castellvi grade, assessment of spondylolisthesis, and L4-S1 interpedicular distance. A comprehensive hip questionnaire was administered which included Harris Hip Score (HHS) and Hip Disability and Osteoarthritis Outcome Score (HOOS) to assess patient function. Correlations between HHS and HOOS and radiographic spinal measurements were calculated, and p-values were corrected for multiple comparison using the Holm’s method. Results Out of 135 patients, 119 were female (88.1%) and 16 were male (11.9%). Average age of presentation was 34.2 years, and average BMI was 26. There was no statistically significant correlation between Castellvi grade, presence of spondylolisthesis, or L4-S1 interpedicular distance and the patient-reported outcome measures HHS or HOOS. Conversely, a significant correlation was observed between Femoro-Epiphyseal Acetabular Roof (FEAR) index and HOOS of the contralateral hip (correlation coefficient = 0.38, adjusted p = 0.03) and Tönnis angle of AD severity and HHS of the contralateral hip (correlation coefficient = − 0.33, adjusted p = 0.04). Conclusion Severity of spinal anomalies measured by Castellvi grade and spondylolisthesis in patients with AD was not associated with decreased patient function in the ipsilateral diseased hip. To our knowledge, this is the first study to date to report the relationship between radiographically identifiable lumbosacral abnormalities and hip function in AD.

Bone sclerosis is a focal, multifocal, or diffuse increase in the density of the bone matrix on radiographs or computed tomography (CT) imaging. This radiological finding can be caused by a broad spectrum of diseases, such as congenital and developmental disorders, depositional disorders, and metabolic diseases. The differential diagnosis can be effectively narrowed by an astute radiologist in the light of the clinical picture and typical findings on imaging. Some of these lesions are rare and have been described as case reports and series in the literature. This article aims to collate the clinical-radiologic findings of non-infectious and non-neoplastic causes of bone sclerosis with relevant imaging illustrations.

Shoulder osteoarthritis (OA) is a common and debilitating condition and a source of high morbidity and medical expenditures across the world among individuals older than 60 years. Shoulder OA results in the gradual destruction of articular cartilage of the humeral head and glenoid component, causing inflammation, pain, and a restricted range of motion. Most patients are diagnosed with shoulder OA after experiencing shoulder pain and stiffness, and the diagnosis is often made after medical and physical histories are obtained and physical and imaging examinations are performed. Use of various surgical techniques such as total anatomic or reverse shoulder arthroplasty and hemiarthroplasty has increased in recent years, resulting in reduced morbidity and improved functional status of patients. However, the rate of surgical complications such as premature loosening of components is significant, reducing the effectiveness of such procedures. Data in the literature indicate that high-grade fatty infiltration of the rotator cuff muscle before surgery is associated with postoperative glenoid component loosening. High-grade rotator cuff fatty infiltration and atrophy have been found to be associated with more severe Walch classification-based glenoid morphology subtypes, increased joint line medialization, glenoid bone loss, and increased pathologic glenoid version. The authors describe how advanced imaging techniques are used for preoperative evaluation of the shoulder and discuss how to measure glenoid version and bone stock and classify glenoid morphology types on the basis of Walch classification, as these parameters are commonly used in surgical planning. Methods involving the use of Friedman and paleoglenoid lines for respective measurements are illustrated by using three-dimensional CT and MRI case examples. ©RSNA, 2020.

Introduction: MR neurography (MRN) of the brachial plexus has emerged in recent years as a safe and accurate modality for the identification of brachial plexopathies in pediatric and adult populations. While clinical differentiation of brachial plexopathy from cervical spine-related radiculopathy or nerve injury has long relied upon nonspecific physical exam and electrodiagnostic testing modalities, MRN now permits detailed interrogation of peripheral nerve anatomy and pathology, as well as assessment of surrounding soft tissues and musculature, thereby facilitating accurate diagnosis. The reader will learn about the current state of brachial plexus MRN, including recent advances and future directions, and gain knowledge about the adult and pediatric brachial plexopathies that can be characterized using these techniques.Areas Covered: The review details recent developments in brachial plexus MRN, including increasing availability of 3.0-T MR scanners at both private and academic diagnostic imaging centers, as well as the advent of multiple new vascular and fat signal suppression techniques. A literature search of PubMed and SCOPUS was used as the principal source of information gathered for this review.Expert Opinion: Refinement of fat-suppression, 3D techniques and diffusion MR imaging modalities has improved the accuracy of MRN, rendering it as a useful adjunct to clinical findings during the evaluation of suspected brachial plexus lesions.

Glenoid bone stock and morphology and rotator cuff muscle quality and tendon integrity affect the outcome of total shoulder arthroplasty. We hypothesized that glenoid bone loss correlates with rotator cuff muscle fatty infiltration (FI), tendinopathy, and atrophy.Forty-three 3D CT scans and MRIs of 43 patients (mean age 62 years; SD 13 years; range 22-77 years) referred for primary shoulder pain were evaluated. Measurements of glenoid bone stock, version, and posterior humeral subluxation index (HSI) were assessed on an axial CT image reconstructed in the true scapular plane. Measurements utilized the Friedman line to approximate the pre-pathologic surface. Glenoid morphology was assigned by modified Walch classification. Rotator cuff FI, atrophy, and tendon integrity were assessed on corresponding MRIs.There was a very strong negative correlation between increasing glenoid version and HSI (r = - 0.908; p 0.0001). There was a moderately negative correlation between anterior bone loss and HSI (r = - 0.562; p 0.0001) and a moderately positive correlation between posterior bone loss and HSI (r = 0.555; p 0.0001). Subscapularis muscle FI correlated moderately with increased anterior and central bone loss and increased humeral head medialization (r = 0.512, p = 0.0294; r = 0.479, p = 0.033; r = 0.494, p = 0.0294; respectively). Inter-observer reliability (intra-class correlation coefficient [ICC] and kappa) was good to excellent for all measurements and grading.Glenoid anteversion and anterior and posterior bone loss are associated with varying HSI. Subscapularis muscle FI, not tendon integrity, correlates to anterior and central glenoid erosion. The study adds evidence that neither rotator cuff tendinopathy nor muscle atrophy exhibits a significant relationship to HSI.

To test the diagnostic efficacy of a multiparametric rheumatology lumbosacral magnetic resonance (MR) imaging protocol in detection and characterization of axial spondylarthritis (SpA) and compare it with serology and clinical findings.A consecutive series of multiparametric rheumatology lumbosacral MR imaging examinations performed on 3T MR scanner. Three-dimensional inversion recovery turbo spin echo, precontrast and postcontrast fat-suppressed T1-weighted images, as well as diffusion-weighted images were used to detect active erosions and enthesitis using established criteria. Pearson χ2 was used for categorical variables. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were measured for magnetic resonance imaging (MRI) and serology, based on the final diagnosis from rheumatologists. An alpha error below 0.05 was considered statistically significant.The final study sample included 130 consecutive patients (80 women and 50 men; mean ± SD 44 ± 13 and 45 ± 14 years, respectively). Seventy-eight subjects were diagnosed with axial SpA and 52 with non-SpA arthropathy. In the non-SpA group, 27 patients were diagnosed with osteoarthritis, 6 had unremarkable imaging, whereas 19 were considered as clinically undetermined. There was positive correlation between positive MRI results and SpA diagnosis (P0.00001). No correlation existed between positive serology alone and SpA diagnosis (P = 0.0634). Although MRI and serology proved equally sensitive in detecting SpA, the specificity and overall accuracy of MRI were significantly higher. Inflammatory activity was detected in 45 (57.7%) cases, in the pelvic enthesis in 29 (37.2%) cases, in the lumbosacral spine in 16 (20.5%) cases, in the hip joints in 15 (19.2%) cases, and in the pubic symphysis in 5 (6.4%). Inactive sacral disease was seen in 7 of 35 enthesitis patients (20.0%), and in 2 SpA cases, there were no sacral lesions.The results suggest that in patients with suspected SpA, MRI should not be limited to the sacroiliac joints, but also include enthesitis sites and other joints of the axial skeleton. The multiparametric rheumatology protocol increases the efficacy of MRI in detecting enthesitis and joint inflammatory disease, thereby offering additional information to the clinician and assisting in the early diagnosis/detecting disease activity.

A standardized guideline and scoring system should be used for the MR imaging diagnosis of peripheral neuropathy. The MR imaging-based Neuropathy Score Reporting and Data System (NS-RADS) is a newly devised classification system (in press in AJR) that can be used to communicate both type and severity of peripheral neuropathy in the light of clinical history and examination findings. The spectrum of neuropathic conditions and peripheral nerve disorders covered in this system includes nerve injury, entrapment, neoplasm, diffuse neuropathy, and post-interventional states. This classification system also describes the temporal MR imaging appearances of regional muscle denervation changes. This review article is based on the multicenter validation study pre-published in American journal of Roentgenology and discusses technical considerations of optimal MR imaging for peripheral nerve evaluation and discusses the NS-RADS classification and its severity scales with illustration of conditions that fall under each classification. The readers can gain knowledge of the NS-RADS classification system and learn to apply it in their practices for improved inter-disciplinary communications and timely patient management.

Imaging plays an essential role in diagnosing and managing musculoskeletal soft tissue masses. It provides anatomic details and aids in the characterization and prognostication of tumors. Advanced imaging is also essential for assessing treatment response and post-treatment surveillance. Several novel imaging techniques are now available that provide additional functional and metabolic information about these tumors. This additional information may be used to predict the biological behavior of the tumors and effectively assess the treatment response for optimizing their management. This article focuses on multiparametric imaging evaluation of soft tissue masses with a discussion of advancements in the domains of ultrasound, MRI, and CT imaging and how these may be helpful in pre- and post-treatment assessment of soft tissue tumors. Current perspectives on the role of diffusion imaging, perfusion imaging, and MR spectroscopy have been highlighted, and future directions of metabolic imaging are briefly outlined. As these advances hold a promising role in the multidisciplinary management of soft tissue sarcomas, it is important for the radiologist to be familiar with the latest advances and developments in imaging soft tissue tumors.

Many patients electing to undergo total hip arthroplasty (THA) value continuing active lifestyles when considering treatment options. Addressing these concerns requires evaluating the effect of preoperative activity level on patient-reported outcomes and improvement following THA.Three hundred thirty-five patients (368 hips) who underwent THA with a minimum 6-month (mean 533 ± 271 days) follow-up completed preoperative and postoperative University of California, Los Angeles (UCLA) activity score along with various patient-reported measures of function, pain, and mental state. Preoperative UCLA score divided patients into inactive, mild, and active groups. Analysis of covariance controlling for age, sex, body mass index, surgical approach, implant, bilateral cases, conversions, and follow-up time evaluated differences among groups for postoperative outcomes with subsequent Tukey-Kramer pairwise comparisons.Mildly active patients (73:139 male:female) had better postoperative outcomes than inactive patients (40:70 male:female) for UCLA score, EuroQol Visual Analog Scale (EQVAS), Hip Outcome Score (HOS), 12-item Short-Form (SF-12) Physical, and Visual Analog Pain Scale (average/now/worst) (P values0.001/0.001/0.001/0.001/0.003/0.001/0.001). Active patients (32:14 male:female) had better postoperative outcomes than inactive patients for UCLA score, EQVAS, HOS, SF-12 Physical, and Visual Analog Pain Scale Worst (P values0.001/0.024/0.001/0.001/0.017). No postoperative outcome differences existed between active and mild patients. Inactive patients displayed greater outcome improvements than mildly active patients for UCLA score, Harris Hip Score, and International Hip Outcome Tool (P values0.001/0.001/0.013) and active patients for UCLA score, EQVAS, HOS, International Hip Outcome Tool, and SF-12 Physical (P values0.001/0.008/0.013/0.022/0.004).Inactive patients achieve greater measure improvements following THA. Active patients achieve better absolute outcomes than inactive patients; however, increasing activity levels do not incrementally improve patient-reported outcome measures. Patients similarly improve pain and mental health regardless of activity level.

Musculoskeletal (MSK) radiologists are predominantly consultants in the service departments of health care. Unlike the manufacturing industry, quality controls are difficult to institute in a service industry and more variability is expected. Structured reporting is a unique way to institute quality standards, and by using the checklist approach with uniform terminology, it can lead to more homogeneity and consistency of reporting, concise lexicon use within and across practices, minimization of errors, enhancement of divisional and departmental branding, improvement of interdisciplinary communications, and future data mining. We share our experience from more than a decade of structured reporting in the domain of MSK radiology, our practice standards, and how reporting has evolved in our MSK practice. Further discussions include future directions aided by machine learning approaches with augmented reality and the possibility of virtual fellowship and training using consistent lexicons and structured reporting.

Anterior cruciate ligament (ACL) injury is a common indication for sports-related major surgery and accounts for a large proportion of ligamentous injuries in athletes. The advancements in 2D and 3D MR imaging have provided considerable potential for a one-stop shop radiation-free assessment with an all-in-one modality examination of the knee, for both soft-tissue and bone evaluations. This article reviews ACL injuries and types of surgical managements with illustrative examples using high resolution 2D and 3D MR imaging. Various complications of ACL reconstruction procedures are highlighted with a focus on the use of advanced MR imaging and relevant arthroscopic correlations.

• Neuropathy imaging is not that complicated or illusive that it needs a touch of genius.• By gaining MR imaging expertise of peripheral nerve lesions and using knowledge of common clinical patterns and diseases, general radiology practitioners can prudently participate in the multidisciplinary care for appropriate and timely management of peripheral neuropathy patients.

MR imaging of joints, particularly shoulder, requires a high degree of spatial resolution to ascertain anatomy and pathology. Unfortunately, motion artifacts can reduce the clinical quality of the examinations. BLADE sequence reduces motion degradation improving overall diagnostic imaging quality. The objective was to compare standard, rectilinear k-space coverage turbo spin echo (TSE), and BLADE sequences.Over a 4-month period, fifty-seven consecutive patients (22 males, 35 females; mean age: 48.5 years, range: 23-64 years) were scanned using traditional intermediate-weighted spin echo and BLADE sequences. Qualitative evaluation was performed by three musculoskeletal fellowship trained radiologists, each with more than 5 years of experience. Image sequences were evaluated using a Likert scale for each of the following five categories: motion degradation, ghosting/phase misregistration artifacts, star/radial encoding artifacts, fat suppression quality, and overall diagnostic quality. Additionally, image sequences were evaluated for signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) using manually drawn regions of interest (ROI) analysis.Ghosting and phase artifacts were lower within BLADE sequence while streak artifacts were higher (p 0.001). Image fat suppression, tendon and labral appearances, and the overall SNR and CNR were comparable on both sequences (p 0.05).Addition of BLADE reduces motion degradation and improves overall diagnostic imaging quality. Application of BLADE in patient scans suspected of motion artifacts can reduce the frequency of repeat imaging in patients with claustrophobia or those where motion is a concern. By reducing overall imaging time and call backs, it could reduce the cost burden to patients and healthcare system.

To determine whether size of the piriformis muscle, as characterized by either the coronal width or a segmented volume, correlates with outcomes after CT-guided injections.A consecutive series of 81 patients with piriformis syndrome received CT-guided injections of the sciatic nerve and piriformis muscle. Volume and thickness measurements of the piriformis were taken from T1W and T2W pre-injection images by two readers. A logistic regression was used to test volume and size effect on first injection response. A cox proportional hazards model was used to evaluate pain-free survival. Identical analyses were performed to test the effects of muscle mass abnormality, nerve abnormality, body mass index, and presence of a split sciatic nerve.There were 15/94 negative responses, 31/94 possible positive responses, and 48/94 positive responses to CT-guided injection. The average pain-free survival time was 38.91 ± 64.43 days. There was no significant correlation of first injection responses with muscle thickness or volume. There was no significant correlation in pain-free survival for muscle thickness or volume. There was no significant correlation in first injection response or pain-free survival with body mass index, muscle abnormalities, nerve abnormalities, or split sciatic nerves. The intraclass correlation was excellent between the two readers for both muscle volume (0.95-0.98) and thickness (0.92-0.97).Piriformis muscle volume or thickness did not significantly correlate with post-injection outcome (first injection response and pain-free survival). Thus, if the patient has clinical symptoms of piriformis syndrome, the size of muscle should not determine whether injection is advisable.

BACKGROUND: Pyruvate dehydrogenase (PDH) and lactate dehydrogenase are essential for adenosine triphosphate production in skeletal muscle. At the onset of exercise, oxidation of glucose and glycogen is quickly enabled by dephosphorylation of PDH. However, direct measurement of PDH flux in exercising human muscle is daunting, and the net effect of covalent modification and other control mechanisms on PDH flux has not been assessed. PURPOSE: To demonstrate the feasibility of assessing PDH activation and changes in pyruvate metabolism in human skeletal muscle after the onset of exercise using carbon 13 ((13)C) MRI with hyperpolarized (HP) [1-(13)C]-pyruvate. MATERIALS AND METHODS: For this prospective study, sedentary adults in good general health (mean age, 42 years ± 18 [standard deviation]; six men) were recruited from August 2019 to September 2020. Subgroups of the participants were injected with HP [1-(13)C]-pyruvate at resting, during plantar flexion exercise, or 5 minutes after exercise during recovery. In parallel, hydrogen 1 arterial spin labeling MRI was performed to estimate muscle tissue perfusion. An unpaired t test was used for comparing (13)C data among the states. RESULTS: At rest, HP [1-(13)C]-lactate and [1-(13)C]-alanine were detected in calf muscle, but [(13)C]-bicarbonate was negligible. During moderate flexion-extension exercise, total HP (13)C signals (tC) increased 2.8-fold because of increased muscle perfusion (P = .005), and HP [1-(13)C]-lactate–to-tC ratio increased 1.7-fold (P = .04). HP [(13)C]-bicarbonate–to-tC ratio increased 8.4-fold (P = .002) and returned to the resting level 5 minutes after exercise, whereas the lactate-to-tC ratio continued to increase to 2.3-fold as compared with resting (P = .008). CONCLUSION: Lactate and bicarbonate production from hyperpolarized (HP) [1–carbon 13 {(13)C}]-pyruvate in skeletal muscle rapidly reflected the onset and the termination of exercise. These results demonstrate the feasibility of imaging skeletal muscle metabolism using HP [1-(13)C]-pyruvate MRI and the sensitivity of in vivo pyruvate metabolism to exercise states. © RSNA, 2021 Online supplemental material is available for this article.

High-resolution ultrasonography (US) and magnetic resonance neurography (MRN) have followed parallel paths for peripheral nerve imaging with little comparison of the two modalities. They seem equally effective to study a variety of neuropathies affecting large and small nerves in the wrist and hand. This article outlines the technical considerations of US and MRN and discusses normal and abnormal imaging appearances of hand and wrist nerves from etiologies such as entrapment, injury, tumor, and proximal and diffuse neuropathy, with specific case illustrations.

Aims Some patients presenting with hip pain and instability and underlying acetabular dysplasia (AD) do not experience resolution of symptoms after surgical management. Hip-spine syndrome is a possible underlying cause. We hypothesized that there is a higher frequency of radiological spine anomalies in patients with AD. We also assessed the relationship between radiological severity of AD and frequency of spine anomalies. Methods In a retrospective analysis of registry data, 122 hips in 122 patients who presented with hip pain and and a final diagnosis of AD were studied. Two observers analyzed hip and spine variables using standard radiographs to assess AD. The frequency of lumbosacral transitional vertebra (LSTV), along with associated Castellvi grade, pars interarticularis defect, and spinal morphological measurements were recorded and correlated with radiological severity of AD. Results Out of 122 patients, 110 (90.2%) were female and 12 (9.8%) were male. We analyzed the radiographs of 122 hips (59 (48.4%) symptomatic left hips, and 63 (51.6%) symptomatic right hips). Average age at time of presentation was 34.2 years (SD 11.2). Frequency of LSTV was high (39% to 43%), compared to historic records from the general population, with Castellvi type 3b being the most common (60% to 63%). Patients with AD have increased L4 and L5 interpedicular distance compared to published values. Frequency of pars interarticularis defect was 4%. Intraclass correlation coefficient for hip and spine variables assessed ranged from good (0.60 to 0.75) to excellent (0.75 to 1.00). Severity of AD did not demonstrate significant correlation with frequency of radiological spine anomalies. Conclusion Patients with AD have increased frequency of spinal anomalies seen on standard hip radiographs. However, there exists no correlation between radiological severity of AD and frequency of spine anomalies. In managing AD patients, clinicians should also assess spinal anomalies that are easily found on standard hip radiographs. Cite this article: Bone Joint J 2021;103-B(8):1351–1357.

The relationship among the severity of the imaging features of femoroacetabular impingement syndrome (FAIS), patient symptoms, and function has not been elucidated. Understanding this relationship helps to improve the prognostic value of imaging. The goal of this study was to examine the correlation of clinical findings, patient pain, and function with severity, as measured with radiographic and 3-dimensional magnetic resonance imaging (3D-MRI). Data collected prospectively through a longitudinally maintained hip database were reviewed, and 37 hips from 31 patients were included. All patients were examined by an experienced orthopedic surgeon, and preoperative radiographs and 3D-MRI were obtained. Preoperatively, the patients completed validated patient-reported outcome measures (PROMs). Mean±SD alpha angles were 69.4°±10.3°, 70.0°±10.3°, 70.6°±8.4°, and 74.8°±9.2° at 12 o'clock, 1 o'clock, 2 o'clock, and 3 o'clock, respectively. Mean lateral center edge angle was 30.1°±5.3°. The authors did not observe a statistically significant correlation between PROMs and the features measured by radiographs and 3D-MRI ( P >.05). In this subset of prospectively imaged patients with FAIS, the authors did not find a correlation between the severity of symptoms measured by PROMs and features on radiographs and 3D-MRI. The severity of dysfunction is multifactorial, and anatomic severity, as measured radiographically and with 3D-MRI, may not correlate with symptoms. Further investigation is necessary to address the sources of patient pain. [ Orthopedics . 2021;44(4):e577–e582.]

To develop and validate an Osseous Tumor Reporting and Data System (OT-RADS) with the hypothesis that the proposed guideline is reliable and assists in separating benign from malignant osseous tumors with a good area under the curve, and that could assist further patient management.In this multireader cross-sectional validation study, an agreement was reached for OT-RADS categories based on previously described magnetic resonance imaging features and consensus of expert musculoskeletal radiologists. World Health Organization classification was used, and a wide spectrum of benign and malignant osseous tumors was evaluated. Magnetic resonance imaging categories were as follows: OT-RADS 0-incomplete imaging; OT-RADS I-negative; OT-RADS II-definitely benign; OT-RADS III-probably benign; OT-RADS IV-suspicious for malignancy or indeterminate; OT-RADS V-highly suggestive of malignancy; and OT-RADS VI-known biopsy-proven malignancy or recurrent malignancy in the tumor bed. Four blinded readers categorized each tumor according to OT-RADS classification. Intraclass correlation (ICC) and Conger κ were used. Diagnostic performance measures including area under the receiver operating curve were reported. Osseous Tumor Reporting and Data System was dichotomized as benign (I-III) and malignant (IV and V) for calculating sensitivity and specificity.Interreader agreement for OT-RADS (ICC = 0.78) and binary distinction of benign versus malignant (κ = 0.67) were good to excellent, while agreement for individual tumor feature characteristics were poor to fair (ICC = 0.25-0.36; κ = 0.16-0.39). The sensitivities, specificities, and area under the receiver operating curve of the readers ranged from 0.93-1.0, 0.71-0.86, and 0.92-0.97, respectively.Osseous Tumor Reporting and Data System lexicon is reliable and helps stratify tumors into benign and malignant categories. It can be practically used by radiologists to guide patient management, improve multidisciplinary communications, and potentially impact outcomes.

To quantify and compare signal intensity (SI) changes on T1-weighted (W) and T2W Dixon imaging in yellow marrow, red marrow, and bone marrow lesions. A total of 141 patients (77 controls, 64 lesions—33 benign, 31 malignant) between January 2016 and December 2017 were retrospectively identified. For the control group, fixed 2-cm2 region of interests (ROI) were drawn at L5, bilateral ilium and femurs on in-phase and opposed-phase T1W and T2W Dixon images. For the lesion group, ROIs of best fit were drawn around each lesion on in-phase and opposed-phase T2W Dixon images. SI changes between in-phase and opposed phase maps for each group were compared. Inter-reader analysis was performed. Yellow marrow exhibited smaller SI changes as compared to red marrow on both T1W and T2W Dixon imaging at all locations (p

To quantify and compare changes in bone mineral density (BMD) via CT analysis in patients with and without spontaneous femoral fractures.Consecutive series of patients with CT imaging for spontaneous femoral fractures were compared to the age and gender matched controls. Bone density fixed region of interest measurements were obtained at the site of the fracture, proximally at the femoral head, and distally at the lesser trochanter in fracture patients and controls. Inter- and intrapatient comparisons were performed, including Chi-square and t-test analyses.24 spontaneous fractures and 25 controls were analyzed with no significant differences in mean age, gender, or body mass index. There were differences in the bone density between the fracture and contralateral non-fracture sides at (p = 0.0001) and distal (p 0.0001) to the fracture. Proximal and distal bone density differences existed between case fracture and control non-fracture sites (p 0.0001, p = 0.0001), and between the case non-fracture and control non-fracture sites (p 0.0001, p 0.0001). The reliability for measurements was good to excellent proximally (ICC = 0.63-0.87), moderate to excellent at the fracture site (ICC = 0.43-0.78), and fair to good distal (ICC = 0.24-0.68) to the fracture site.Patients with spontaneous femoral fractures exhibit lower bone density than the asymptomatic controls. Bone insufficiency is best demonstrated proximal or distal to, rather than at the fracture site.

Aim: To evaluate the utility of percutaneous CT guided bone biopsy (PCBB) for suspected osteomyelitis (OM) and its eventual impact on patient management and recovery. Material and methods: Patients who received a PCBB for suspected osteomyelitis from years 2012-2018. Patient demographics, lesion location, ulcer grade, signs of toxemia, serology, wound and blood cultures, bone biopsy and cross-sectional imaging results were recorded. Diagnostic yield of the bone biopsy and its role in influencing the final treatment plan and patient recovery were evaluated. Chi-square test was used. P-value less than 0.05 was considered statistically significant. Results: 115 patients with mean age 50.86 ± 14.49 years were included. The common locations were sacrum/ischium (49/115, 43%) and spine (35/115, 30%). Clinically, 40/115 (35%) had toxemia and 67/115 (58%) had ulcers. Per serology, 17/111 (15%), 95/106 (90%), and 86/98 (88%) had an elevated WBC, CRP, and sedimentation rate, respectively. 22/91 (24%) had a positive blood culture and all 23/23 had a positive wound culture. On imaging, definitive and possible OM were reported in 84.1% and 14.2%, respectively, with 1.8% as no OM. Only 24/115 (21%) had a positive bone biopsy culture and only 10/24 (42%) total positive bone cultures impacted the treatment plan. There was no significant effect of antibiotics on the diagnostic yield of culture (p = 0.08). No statistical significance was found when comparing treatment change based on bone culture results versus all other factors combined (p = 0.33), or when comparing clinical improvement with and without positive bone cultures (p = 0.12). Conclusion: Despite positive cross-sectional imaging findings of OM, bone biopsy yield of positive culture is low, and it leads to a small impact in changing the treatment plan or altering the course of patient recovery.

Aim Radiographs (X-rays) are used for the preoperative assessment of hallux valgus (HV). Our purpose was to determine how well quantitative measurements of HV on radiographs and MRI correlate with the qualitative soft tissue and internal derangement findings on MRI. Materials and methods After IRB approval, 56 consecutive patients with MRI and radiographs of the foot were retrospectively reviewed. Two trained readers independently evaluated radiographs, measuring hallux valgus angle (HVA) and intermetatarsal angle (IMA). Two separate readers assessed qualitative MRI data by evaluating 21 different soft tissue and bony features. Statistical analysis included inter-reader reliability (IRR) and correlation of quantitative and qualitative findings. Results Excellent IRR (ICC = 0.89–0.96) was observed for radiograph and MRI measurements of the hallux valgus severity. For qualitative assessments on MRI, IRR was good to excellent for all features (ICC = 0.63–0.9). No significant difference was found for HVA or IMA between normal and abnormal qualitative MRI features. No statistically significant correlation between the severity of hallux valgus and injury to hallux joints and supporting structures was found. Conclusion Hallux valgus measurements are reliable on x-rays and MRI and qualitative findings of 1st MTP joint show good to excellent inter-reader agreement on MRI. No statistically significant correlations exist between the severity of hallux valgus and qualitative MRI findings.

Determine correlations of 3DCT cam-type femoroacetabular impingement (FAI) measurements with surgical findings of labral tear and cartilage loss. Digital search of symptomatic cam-type FAI from July 2013 to August 2016 yielded 43 patients. Two readers calculated volumes of femoral head, bump, and alpha angles on 3DCT images. Correlations between CT and surgical findings, inter-, and intra-reader reliabilities were assessed using Spearman rank correlation and intraclass correlation coefficients (ICC). Thirteen men and 14 women aged 37 ± 10 (mean ± SD) years were included. Most common clinical finding was positive flexion–adduction–internal rotation (70.4%). Twenty-seven labral tears and 20 cartilage defects were surgically detected. Significant correlations existed between femoral bump, head volumes, and extent of the labral tear (p = 0.008 and 0.003). No significant correlations were found between the alpha angles at 12 to 3 o’clock and the extent of labral tear (p = 0.2, 0.8, 0.9, and 0.09) or any measurement with the cartilage loss (p values for alpha 12 to 3, bump, and head volumes = 0.7, 0.3, 0.9, 0.9, 0.07, and 0.2). Inter- and intra-reader reliabilities were excellent to moderate for femoral head and bump volumes (ICC = 0.85, 0.52, and 0.8, 0.5) and moderate to poor for alpha angles (ICC = 0.48, 0.40, 0.05, 0.25 and 0.3, 0.24, 0.29, 0.49). Three dimensional volumetric measurements of cam-type FAI significantly correlate with the extent of intraoperative labral tears. Superior inter- and intra-reader reliability to that of alpha angles renders it a more clinically relevant measurement for quantifying cam morphology. • The 3DCT bump volume and femoral head volume showed significant correlations with the extent of labral tear (p values = 0.008 and 0.003). • No significant correlations were seen between alpha angles and the extent of labral tear (p values > 0.05). • Inter- and intra-reader reliability was excellent to moderate (ICC = 0.85 and 0.52, 0.8, and 0.5) for femoral head and bump volumes while inter- and intra-reader reliability was fair to poor (ICC = 0.48, 0.40, 0.05, 0.25 and 0.3, 0.24, 0.29, 0.49) for alpha angles.

Purpose The accuracy of magnetic resonance neurography (MRN) for quantitative assessment of nerve injury gap is unknown. We tested the hypothesis that presurgical MRN predicts the final surgical gap size after neuroma resection at the time of surgery. Materials and Methods This was a retrospective, single-blinded, nonrandomized cohort study on 43 patients with Sunderland Class IV and V injuries of the inferior alveolar (IAN) or the lingual nerve (LN). The MRN maxillofacial protocol was performed on a 3T scanner and was read by 2 musculoskeletal radiologists to determine the maximum size of neuroma and the abnormal nerve segment. Two independent variables were recorded during surgery: 1) the length of neuroma from histologic specimens since only 9 of the 43 neuroma size measurements were accurately measureable at the time of surgery; and 2) the length of nerve gap size after the neuroma was removed and normal fascicles were identified. Results There were 7 IAN and 36 LN cases analyzed. The mean time in months from injury to MRN was 6.97 ± 9.18 and MRN to surgery was 1.21 ± 1.4. The mean length of the neuroma at surgery was 7.22 ± 2.78 mm and mean nerve gap size was 12.02 ± 4.41 mm. Intraclass coefficient (ICC) agreement was fair for abnormal nerve thickness and neuroma length (ICC = 0.28, 0.39) while it was moderate for neuroma thickness and abnormal nerve length (0.50, 0.59). There was no significant correlation between MRN based measurements and surgical gap size for both readers (P > .05). Conclusions Abnormal nerve and neuromas of the peripheral trigeminal nerve as identified on MRN imaging demonstrates no correlation of the assessed MRN findings with the final surgical gap after neuroma removal.

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms composed of spindled to epithelioid cells that co-express both melanocytic and myogenic markers. Recently, in 2018, a distinctive variant of PEComa has been described that arises in association with tuberous sclerosis complex (TSC) and resembles a fibroma by conventional morphology (called fibroma-like PEComa). Herein, we describe a case of a fibroma-like PEComa in a 4-year-old male child with a known diagnosis of tuberous sclerosis who presented with a firm mass along the anteromedial aspect of the right knee. The mass was excised, and microscopic examination showed bland spindled to stellate cells embedded in a dense collagenous stroma, morphologically resembling a fibroma. Immunohistochemistry analysis showed positivity for desmin (a myogenic marker) and HMB45 (a melanocytic marker), a hallmark for PEComas. To our knowledge, only six cases of fibroma-like PEComa have been described in the literature so far and this is the first report of such a tumor in the medial retinaculum of the knee joint with illustrations of conventional and diffusion imaging features. This case highlights the unique association of fibroma-like PEComa lesions with TSC. This should be considered a differential diagnosis for T2 hypointense masses in tuberous sclerosis patients. In addition, a diagnosis of fibroma-like PEComa should prompt further evaluation for associated TSC.

Bone tumors and tumor-like lesions (pseudotumors) are not uncommonly encountered as asymptomatic findings on imaging, or as symptomatic lesions clinically. Radiographic imaging is the first diagnostic tool for their management strategy, since the symptoms are commonly non-specific, such as pain, swelling, and redness. Image findings must be analyzed with attention to the specific features such as lesion location, margination, zone of transition, mineralization, size and multifocality, soft tissue component and/or loco-regional extent. Cross-sectional imaging including CT and MRI serve as complementary methods, providing additional information with respect to the lesion characterization, mineralization, extent and involvement of the adjoining soft tissues. Clinical and/or key imaging features aid in limiting the differential diagnostic possibilities and serve as a guide in determining the benignity or malignancy of the tumor as well as to exclude pseudotumors. This article reviews the key imaging features of foot and ankle lesions. Benign bone lesions include simple and aneurysmal bone cysts, lipoma, hemangioma, chondroblastoma, enchondroma, osteoid osteoma, osteoblastoma, and giant cell tumor. Locally aggressive intermediate category lesion includes hemangioendothelioma. Malignant lesions include osteosarcoma, Ewing's sarcoma, chondrosarcoma. Pseudotumors such as fibrous dysplasia, hemophilic pseudotumor, gout and Madura foot are also discussed with illustrative case examples.

Objectives Synovial sarcomas commonly involve extremities. The purpose of this study was to systematically assess and describe the appearance of pathologically proven synovial sarcomas on conventional MR sequences, diffusion weighted imaging and dynamic contrast enhanced imaging. Methods In this cross-sectional retrospective study, fifteen pre-operative MRIs were analyzed separately by two musculoskeletal radiologists and a fellow. MRI features of synovial sarcomas were evaluated in a systematic fashion on conventional and advanced MR sequences. Results The tumors demonstrated heterogeneous appearance on conventional MR sequences. Peritumoral edema was absent in four of 15 (27%) lesions including grade 2 and grade 3 tumors. Average minimum ADC was 0.8 × 10–3 mm2/s and average mean ADC was 1.2 × 10–3 mm2/s. There was avid early arterial phase enhancement on contrast imaging. Average relative enhancement of the tumors was 5.7 times compared to the adjacent skeletal muscle. Conclusion Synovial sarcomas demonstrate avid early arterial phase post-contrast enhancement on contrast images, low ADC values, and heterogeneous appearance on conventional MRI sequences. Peritumoral edema may be absent in such tumors despite being high grade tumors.

Osteoarthritis is one of the most common causes of ambulatory disability. Developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) may lead to premature osteoarthritis in a young adult population. Current clinical assessments of DDH and FAI include clinical history, static radiological metrics, and physical examinations. Methods involving dynamic radiography such as fluoroscopy are costly and time-consuming for both patient and physician. Therefore, our aim was to simulate dynamic gait on 3D static radiological images of hips to generate "virtual interference" points between the femur and acetabulum with three methods of center-of-rotation (COR): static spherical, dynamic spherical, and dynamic ellipsoidal. We simulated the gait kinematics on pre-segmented CT images for three groups: DDH (N=10), FAI (N=10), and asymptomatic normal (N=11). The femoral head was divided into four medial quadrants to compare the ratios of virtual interference within the regions along the gait cycle and as a temporal mean. We hypothesized that discriminating characteristics would exist between the two pathologies and for the dynamic COR methods to have more discriminating characteristics than the static COR method. For each COR method, we found the temporal mean of virtual interference to be significantly different in almost every region between the hip conditions. The significance was most distinct when using the static spherical method of COR. These results are promising to individual clinical assessments of hip pathologies using static radiographs and ultimately work towards preventing premature hip disease.

To analyze the trends in international medical graduates (IMGs) matching into diagnostic radiology residency programs in the United States (US).The National Resident Match Program data was accessed for years 2005-2020 and diagnostic radiology residency-specific data was extracted for US MD, osteopathic (DO), and IMG applicants. IMGs were categorized into US-citizen IMGs and non-US citizen IMGs per the National Residency Match Program. Variables collected for each year included the number of positions, number of applicants in each group, positions filled/unfilled, and fill rate of each group. Additional data for some years included USMLE Step 1 score, United States Medical Licensing Examination (USMLE) Step 2 clinical knowledge (CK) score, number of research experiences, number of abstracts/publications, and additional degrees obtained. Trends were analyzed using simple linear regression model and p value0.05 was considered significant.The number of diagnostic radiology residency programs increased from 203 (2006) to 212 (2020). The total number of diagnostic radiology residency positions increased from 1011 (2006) to 1113 (2020), with the peak of 1145 in 2014. The overall "match rate," that is, proportion of positions filled to positions available, increased from 96.4% (2006) to 97.3% (2020), with a brief decline to 86.7% in 2015. Among the filled positions, the proportion filled by US medical school graduates significantly declined from 89.7% (2006) to 69.2% (2020) (p0.001), and the proportion of positions filled by osteopathic seniors and graduates significantly increased from 2.2% (2006) to 15.1% (2020; p0.001). The proportion of US IMGs increased from 3.2% (2006) to 5.4% (2020), while the proportion of non-US IMGs increased from 4.4% (2006) to 9.4% (2020), with overall IMG match rate increased significantly from 7.6% to 14.9% (p = 0.009). The mean Step 1 scores of US IMGs and non-US IMGs were 238 and 237.3, and the mean Step 2 CK scores were 241.67 and 241, respectively. Cumulatively over the study period, a total of 736 US IMGs and 1051 non-US IMGs have matched into diagnostic radiology residency.There is an increasing proportion of IMGs, especially the non-US citizen IMGs, matching into US radiology residency programs in the last decade. Diagnostic radiology remains a competitive specialty evidenced by average USMLE scores higher than national average and research experiences of matched candidates.