Analysis of Complement Gene Expression, Clinical Associations, and Biodistribution of Complement Proteins in the Synovium of Early Rheumatoid Arthritis Patients Reveals Unique Pathophysiologic Features.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial hyperplasia and inflammation. The finding of autoantibodies in seropositive RA suggests that complement system activation might play a pathophysiologic role due to the local presence of immune complexes in the joints. Our first objective was to explore the Pathobiology of Early Arthritis Cohort (PEAC) mRNA sequencing data for correlations between clinical disease severity as measured by DAS28-ESR (disease activity score in 28 joints for erythrocyte sedimentation rate) and complement system gene expression, both in the synovium and in blood. Our second objective was to determine the biodistribution using multiplex immunohistochemical staining of specific complement activation proteins and inhibitors from subjects in the Accelerating Medicines Partnership (AMP) RA/SLE study. In the PEAC study, there were significant positive correlations between specific complement gene mRNA expression levels in the synovium and DAS28-ESR for the following complement genes: C2, FCN1, FCN3, CFB, CFP, C3AR1, C5AR1, and CR1 Additionally, there were significant negative correlations between DAS28-ESR and Colec12, C5, C6, MASP-1, CFH, and MCP In the synovium there were also significant positive correlations between DAS28-ESR and FcγR1A, FcγR1B, FcγR2A, and FcγR3A Notably, CFHR4 synovial expression was positively correlated following treatment with the DAS28-ESR at 6 mo, suggesting a role in worse therapeutic responses. The inverse correlation of C5 RNA expression in the synovium may underlie the failure of significant benefit from C5/C5aR inhibitors in clinical trials performed in patients with RA. Multiplex immunohistochemical analyses of early RA synovium reveal significant evidence of regional alterations of activation and inhibitory factors that likely promote local complement activation.

SSR white paper: guidelines for utilization and performance of direct MR arthrography.

OBJECTIVE: Direct magnetic resonance arthrography (dMRA) is often considered the most accurate imaging modality for the evaluation of intra-articular structures, but utilization and performance vary widely without consensus. The purpose of this white paper is to develop consensus recommendations on behalf of the Society of Skeletal Radiology (SSR) based on published literature and expert opinion. MATERIALS AND METHODS: The Standards and Guidelines Committee of the SSR identified guidelines for utilization and performance of dMRA as an important topic for study and invited all SSR members with expertise and interest to volunteer for the white paper panel. This panel was tasked with determining an outline, reviewing the relevant literature, preparing a written document summarizing the issues and controversies, and providing recommendations. RESULTS: Twelve SSR members with expertise in dMRA formed the ad hoc white paper authorship committee. The published literature on dMRA was reviewed and summarized, focusing on clinical indications, technical considerations, safety, imaging protocols, complications, controversies, and gaps in knowledge. Recommendations for the utilization and performance of dMRA in the shoulder, elbow, wrist, hip, knee, and ankle/foot regions were developed in group consensus. CONCLUSION: Although direct MR arthrography has been previously used for a wide variety of clinical indications, the authorship panel recommends more selective application of this minimally invasive procedure. At present, direct MR arthrography remains an important procedure in the armamentarium of the musculoskeletal radiologist and is especially valuable when conventional MRI is indeterminant or results are discrepant with clinical evaluation.

The effect of virtual interviews on the musculoskeletal radiology fellowship match.

OBJECTIVE: Resulting from the COVID-19 pandemic, a virtual interview format was adopted in lieu of in-person interviews for fellowship recruitment. The purpose of this study is to analyze the potential effect that virtual interviews have on musculoskeletal radiology fellowship match results and collect opinions of the process. MATERIALS AND METHODS: An anonymous survey was sent to 87 listed US-based musculoskeletal radiology fellowship directors, who were asked for their 2019-2020 and 2020-2021 match data: fellowship positions, interviewees, ranked interviewees, and matched ranks. They rated effectiveness of virtual interviews on a ten-point scale (1 poor-10 excellent) and provided an ideal percentage of future interviews to be conducted virtually. RESULTS: Thirty responses were received (34.4% response rate). Primary analysis found significant increase in the mean number of candidates ranked in 2020-2021, 14.6 to 17.5 (p = 0.047). The mean rank of matched applicants increased from 6.02 to 6.43, without significance (p = 0.821). Secondary analysis, which attempted to exclude internally matched programs, found significant increases in 2020-2021 in the mean number of applicants-28.7 to 32.4 (p = 0.017), interviews conducted-17.8 to 21.3 (p = 0.007), and candidates ranked by programs-16.3 to 19.8 (p = 0.015). The mean rank of matched applicants increased from 6.39 to 7.03, without significance (p = 0.713). CONCLUSION: With results showing an increase in applications, interviews conducted, and ranked applicants while lowering the average rank of matched candidates, musculoskeletal radiology fellowship directors should consider interviewing more applicants than they usually would in the prior in-person recruitment format.

Radiographic assessment of acute vs chronic vertebral compression fractures.

PURPOSE: Distinguishing between acute and chronic vertebral compression fractures typically requires advanced imaging techniques such as magnetic resonance imaging (MRI). Recognizing specific radiographic findings associated with fracture acuity may improve the accuracy of radiographic assessment. METHODS: Patients with compression fractures that had both radiographic and MRI studies of the lumbar spine within a 30-day time frame were retrospectively reviewed. MRI studies were used to determine compression fracture acuity. Radiographs were interpreted by a separate group of radiologists blinded to the MRI results. Radiographic findings of endplate osteophyte, subendplate density, subendplate cleft, and subendplate cyst were recorded as was the overall impression of fracture acuity. RESULTS: Sensitivity and specificity for radiographic reporting of acute fracture were 0.52 (95% CI: 0.42, 0.61) and 0.95 (95% CI: 0.93, 0.97) respectively. For chronic fractures, the sensitivity and specificity were 0.52 (95% CI: 0.41, 0.63) and 0.94 (95% CI: 0.92, 0.96). The radiographic presence of a subendplate cleft increased the odds of a fracture being acute by a factor of 1.75 (95% CI: 1.09, 2.81; P = 0.0202). The radiographic presence of subendplate density increased the odds of a fracture being acute by a factor of 1.78 (95% CI: 1.21, 2.63; P = 0.0037). The presence of an endplate osteophyte or subendplate cyst was not significantly associated with fracture acuity. CONCLUSION: Radiographs are relatively insensitive in distinguishing between acute and chronic lumbar compression fractures but the presence of a subendplate cleft or subendplate density increases the likelihood that a given fracture is acute.

Accuracy of long head of the biceps tendon palpation by physical therapists; an ultrasonographic study.

[Purpose] Examination and treatment of the long head of the biceps tendon (LHBT) requires accurate palpation. The purpose of this study was to determine physical therapists' reliability and ability to accurately palpate the LHBT in two arm positions with ultrasound as the gold standard. [Participants and Methods] Examiners palpated the LHBT within the intertubercular groove (ITG) of the humerus on the bilateral shoulders of 32 asymptomatic (21 female; 24.3 ± 1.9 years) participants in 2 arm positions. The magnitude of distance between a marker and the border of the ITG was compared between 2 positions using an independent t-test. Percent accuracy was calculated. [Results] Inter-rater reliability was poor (position 1, k=1.04; position 2, k=0.016). Overall accuracy rate was 45.7% (117/256). Accuracy was 49.2% (63/128) and 42.2% (54/128) for testing position 1 and position 2 respectively. Mean distance palpated from the groove was M=2.58 mm (± 6.2 mm) for position 1 and M=3.77 mm (± 6.6 mm) for position 2. Inaccurate palpation occurred medially 72.3% (47/65) and 93.2% (69/74) in position 1 and position 2 respectively. [Conclusion] Results of this study did not support one arm position being more accurate over another for LHBT palpation.

Postoperative Imaging of the Ankle.

OBJECTIVE: The purpose of this article is to review imaging after commonly encountered surgical interventions of the ligaments, tendons, and soft tissues around the ankle. Intraoperative images, when available, are provided to improve conceptual understanding of these complex procedures. CONCLUSION: Surgical interventions in the ankle are becoming more prevalent with increasing athletic demands and emerging focus on techniques for prevention of joint injury. Knowledge of the surgical techniques, imaging appearances, and complications in the postoperative ankle is necessary for the accurate diagnosis of postoperative complications and for optimal patient care.

Postoperative Imaging in the Setting of Hip Preservation Surgery.

Osteoarthritis of the hip remains a prevalent disease condition that influences ever-changing treatment options. Procedures performed to correct anatomic variations, and, in turn, prevent or slow the progression of osteoarthritis, are aptly referred to as types of hip preservation surgery (HPS). Conditions that predispose individuals to femoroacetabular impingement (FAI), including pincer- and cam-type morphology, and hip dysplasia are specifically targeted in HPS. Common surgical interventions include acetabuloplasty, osteochondroplasty, periacetabular osteotomy (PAO), and derotational femoral osteotomy (DFO). The radiologist's understanding of the surgical approach, pre- and postoperative imaging findings, and common complications of HPS are paramount to providing value to the patient and surgeon. Acetabuloplasty and osteochondroplasty are performed to address pincer- and cam-type morphology in patients with FAI. With both of these HPS techniques, the goal is to restore the normal morphology by resecting excess bone in the acetabulum or femoral head or neck. As a result, a frequently encountered complication is incomplete or excessive resection. Excessive resection can predispose the patient to dislocation in the case of acetabuloplasty and fracture in the case of osteochondroplasty. Iatrogenic injury to adjacent structures such as the ischiofemoral ligament and acetabular cartilage also may occur. Although rare, especially when an arthroscopic approach is used, avascular necrosis remains a risk. Femoral head undercoverage in hip dysplasia is corrected by using PAO, which may be performed as the sole procedure or in conjunction with DFO. Incomplete or excessive rotation during surgery can result in postprocedural complications. As with any orthopedic procedure involving osteotomy, nonhealing is a risk. Iatrogenic injury in the form of fracture or hardware failure also may be seen. ©RSNA, 2016.

Introduction of a virtual workstation into radiology medical student education.

OBJECTIVE. This article describes the creation of a virtual workstation for use by medical students and implementation of that workstation in the reading room. CONCLUSION. A radiology virtual workstation for medical students was created using OsiriX imaging software to authentically simulate the experience of interacting with cases selected to cover important musculoskeletal imaging diagnoses. A workstation that allows the manipulation and interpretation of complete anonymized DICOM images may enhance the educational experience of medical students.

Validation of a new radiographic measurement of acetabular version: the transverse axis distance (TAD).

OBJECTIVES: This study has three aims: (1) validate a new radiographic measure of acetabular version, the transverse axis distance (TAD) by showing equivalent TAD accuracy in predicting CT equatorial acetabular version when compared to a previously validated, but more cumbersome, radiographic measure, the p/a ratio; (2) establish predictive equations of CT acetabular version from TAD; (3) calculate a sensitive and specific cut point for predicting excessive CT acetabular anteversion using TAD. MATERIALS AND METHODS: A 14-month retrospective review was performed of patients who had undergone a dedicated MSK CT pelvis study and who also had a technically adequate AP pelvis radiograph. Two trained observers measured the radiographic p/a ratio, TAD, and CT acetabular equatorial version for 110 hips on a PACS workstation. Mixed model analysis was used to find prediction equations, and ROC analysis was used to evaluate the diagnostic accuracy of p/a ratio and TAD. RESULTS: CT equatorial acetabular version can accurately be predicted from either p/a ratio (p < 0.001) or TAD (p < 0.001). The diagnostic accuracies of p/a ratio and TAD are comparable (p =0.46). Patients whose TAD is higher than 17 mm may have excessive acetabular anteversion. For that cutpoint, the sensitivity of TAD is 0.73, with specificity of 0.82. CONCLUSION: TAD is an accurate radiographic predictor of CT acetabular anteversion and provides an easy-to-use and intuitive point-of-care assessment of acetabular version in patients with hip pain.

Video: Ultrasound-guided intervention at the posterior hip.

OBJECTIVE: The purpose of this video article is to demonstrate sonographic anatomy at the posterior hip and to describe a number of diagnostic and therapeutic interventions that may be performed at this location with sonographic guidance. Injection techniques at the piriformis muscle, ischial bursa, hamstring origin, and ischiofemoral space are described and demonstrated. CONCLUSION: Ultrasound is well adapted to the evaluation and treatment of conditions encountered at the posterior hip. Sonographic guidance is a useful tool that allows a trained operator to safely and effectively perform a range of injections.

Strategies for successful integration of work from home faculty in an academic radiology department.

Academic radiology departments have added increasing numbers of entirely remote "work-from-home" or hybrid faculty. This change has presented both an opportunity to recruit and retain faculty as well as a set of challenges to maintaining the full academic mission and educational environment. In this article we describe our experience with creating a remote faculty position and the key elements that we believe made it successful. Guiding principles for the department and faculty member accepting such a position are proposed and discussed.

Brief report: airways abnormalities and rheumatoid arthritis-related autoantibodies in subjects without arthritis: early injury or initiating site of autoimmunity?

OBJECTIVE: To evaluate the presence of pulmonary abnormalities in rheumatoid arthritis (RA)-related autoantibody-positive subjects without inflammatory arthritis. METHODS: Forty-two subjects who did not have inflammatory arthritis but were positive for anti-cyclic citrullinated peptide antibodies and/or ≥2 rheumatoid factor isotypes (a profile that is 96% specific for RA), 15 autoantibody-negative controls, and 12 patients with established seropositive early RA (<1-year duration) underwent spirometry and high-resolution computed tomography (HRCT) lung imaging. RESULTS: The median age of autoantibody-positive subjects was 54 years, 52% were female, and 38% were ever-smokers; these characteristics were not significantly different from those of autoantibody-negative control subjects. No autoantibody-positive subject had inflammatory arthritis based on joint examination. HRCT revealed that 76% of autoantibody-positive subjects had airways abnormalities including bronchial wall thickening, bronchiectasis, centrilobular opacities, and air trapping, compared with 33% of autoantibody-negative controls (P = 0.005). The prevalence and type of lung abnormalities among autoantibody-positive subjects were similar to those among patients with early RA. In 2 autoantibody-positive subjects with airways disease, inflammatory arthritis classifiable as articular RA developed ∼13 months after the lung evaluation. CONCLUSION: Airways abnormalities that are consistent with inflammation are common in autoantibody-positive subjects without inflammatory arthritis and are similar to airways abnormalities seen in patients with early RA. These findings suggest that the lung may be an early site of autoimmune-related injury and potentially a site of generation of RA-related autoimmunity. Further studies are needed to define the mechanistic role of lung inflammation in the development of RA.

Normal anatomy and imaging of the hip: emphasis on impingement assessment.

A comprehensive knowledge of normal hip anatomy and imaging techniques is essential in the evaluation and assessment of the patient with hip pain. This article reviews the osseous, soft tissue, and vascular components of the hip and the normal anatomical variants encountered in routine hip imaging. Basic and advanced hip imaging is discussed with particular emphasis on radiographic and computed tomography measurements and their utility in evaluating patients with developmental hip dysplasia and femoroacetabular impingement syndrome.

MR Imaging of Knee Cartilage Injury and Repair Surgeries.

Cartilage injuries are common and may predispose to early accelerated osteoarthritis. Magnetic resonance (MR) imaging is critical in the detection and characterization of acute and chronic cartilage injuries. Several surgical approaches including microfracture, osteochondral allografting, autologous osteochondral transfer system, and autologous chondrocyte implantation have been developed to treat cartilage lesions. The goals of these treatments include relief of symptoms, restoration of joint function, and delay of progression of osteoarthritis. Imaging evaluation by MR imaging plays a crucial role in diagnosis and surgical planning as well as monitoring for postoperative complications.

Mass-Like Fat at the Medial Midfoot: A Common Pseudolesion.

Background Fatty masses are common and may be encountered in the foot and ankle. In some cases, normal subcutaneous fat may be mistaken for a discrete mass. Aims The aim of this study was to evaluate the common finding of prominent subcutaneous fat at the medial midfoot resembling a lipoma and to determine the prevalence of this pseudolesion by applying a series of potential size cutoff criteria. Materials and Methods Three musculoskeletal radiologists retrospectively evaluated 91 sequentially performed magnetic resonance imaging examinations of the ankle to measure fat resembling a discrete lipoma at the medial midfoot. Each blinded reader measured the largest area of continuous subcutaneous fat in orthogonal axial, coronal craniocaudal, and coronal transverse dimensions. Patient age, sex, and study indications were also recorded. Statistical analysis was performed with R and SAS 9.4 software Results A discrete fatty pseudolesion as defined by measuring at least 1 cm in all planes by measurements of at least two of three readers was present in 87% of cases (79 of 91). When a size criterion of 1.5 cm was used, a pseudolesion was documented in 14% of cases (13 of 91). There was a significant correlation between larger pseudolesion size and female sex in the axial plane; however, there was no correlation in the coronal craniocaudal and coronal transverse dimensions. Conclusions Subcutaneous fat at the medial midfoot often has a mass-like appearance that could be mistaken for a lipoma. It is important to recognize this pseudolesion variant and not to confuse the imaging appearance for a discrete mass.