Faculty Bibliography

OBJECTIVES/OBJECTIVE:To evaluate whether ultrasound-guided preoperative localization of soft tissue masses in the musculoskeletal system using a wireless radar reflector reduces operative times and reoperation rates compared to a control group referred by the same oncology team. METHODS:Retrospective review of SAVI SCOUT radar localizations performed preoperatively for soft tissue masses between 2021 and 2025. All imaging, clinical details, and operative times were evaluated. Comparison was made between the localized group and a control group matched for demographics (age and sex), comorbidities (American Society of Anesthesiologists score), location (trunk versus appendicular; subcutaneous versus deep/subfascial), histopathology (benign versus malignant), and case complexity (primary closure versus flap reconstruction). Cases were performed by the same oncological surgical team referred directly or via the multidisciplinary tumor board during the same time course. RESULTS:Twenty-four radar localized cases were compared with 24 control cases. Median case time in the SAVI SCOUT group was 52.0 minutes (interquartile range 38.0) and there was no significant difference in case times between the localized and control groups (p > .05). There were no reoperations in the localized group whereas 5 patients in the non-localized control group underwent reoperation for positive margins, though this difference fell short of statistical significance (p = .056). The most common lesions in the localized group were metastatic melanoma (12.5%) and intramuscular myxoma (8.3%), liposarcoma (8.3%), and metastatic leiomyosarcoma (8.3%). CONCLUSIONS:Preoperative localization demonstrated no substantial improvement in operative time compared to the non-localized group. However, re-resection rates were higher in the non-localized group.

PURPOSE/OBJECTIVE:The aim of this study is to evaluate the treatment response of patients with osteoid osteoma (OO) following radiofrequency ablation (RFA) and identify factors influencing the time to complete pain relief post-treatment. MATERIALS AND METHODS/METHODS:This is a retrospective cohort study of patients who underwent RFA for OO between 2010 and 2023. Demographic, clinical data, and time between symptoms onset to diagnosis and RFA were recorded. CTs were reviewed for OO location (upper extremity, lower extremity, spine/pelvis), intra-articular versus extra-articular lesions, nidus size, degree of peripheral bone formation, and presence of vessel sign. Procedural related information included needle approach, RFA active tip length, and number of RFA cycles. Statistical analysis was made on factors and their correlation to complete pain relief. RESULTS:Out of 63 patients included in our study (mean age 19.3 ± 10.6), OO were located in the upper extremity (n = 7, 11%), lower extremity (n = 48, 76%), and pelvis/spine (n = 8, 13%). OO in the pelvis/spine achieved the quickest complete pain relief (14 days) compared to those in lower (25 days, 11 days longer) and upper extremity (54 days, 40 days longer) respectively (p = 0.04). Vessel sign had significant association with shorter time to complete pain relief (p = 0.03). Longer duration of symptoms until diagnosis or RFA, larger nidus, more bone formation, and extra-articular OO responded slower to RFA, though statistical significance was not reached. CONCLUSIONS:Anatomical location and certain imaging characteristics of OO may have association with time to complete pain relief following RFA. The findings can potentially help optimizing patient counseling with more realistic expectations and symptom management strategies prior to and following RFA.

PURPOSE/OBJECTIVE:To determine the clinical outcomes of hip arthroscopy for anterior inferior iliac spine subspine impingement (SSI). LEVEL OF EVIDENCE/METHODS:Case Series; level IV. METHODS:Patients who underwent unilateral, primary hip arthroscopy for SSI from February 2015 to December 2017 with minimum 3-year follow-up data were identified (SSI). Analysis of variance, Kaplan-Meier analysis, and regression modeling were used to analyze outcomes. RESULTS:Of 23 eligible, 19 (83% inclusion) patients (mean [standard error of the mean]: age: 45.9 [3.1]; body mass index, 26.3 [0.9]; 79% female, 53% right side) had a minimum of 3-year follow-up (48.3 [2.2] months). The estimated mean survival time of index procedure across the whole cohort was 64.9 ± 3.1 months. One patient underwent total hip arthroplasty. Patients improved from baseline modified Harris Hip Score (62.7 [5.1]) to follow-up (75.1 [4.3]; P = .014). Twelve patients (63%) met minimal clinically importance difference criteria while 7 (37%) met patient acceptable symptomatic state criteria. Linear regression modeling demonstrated lower postoperative lateral center edge angle (beta = -2.1, 95% confidence interval: -0.5 to -2.9, P = .035) and presence of labral repairs (beta = 46.1, 95% confidence interval: 24.8-67.4, P = .003) were associated with higher follow-up modified Harris Hip Score. CONCLUSION/CONCLUSIONS:In conclusion, patients undergoing anterior inferior iliac spine decompression during hip arthroscopy for SSI in the setting of femoroacetabular impingement syndrome have acceptable, improved clinical outcomes at minimum 3-year follow-up. Labral repair and decreasing postoperative lateral center edge angle were predictive of improved patient-reported outcomes. Hip arthroscopy remains a viable successful treatment options in the treatment of concomitant SSI during femoroacetabular impingement syndrome surgery.

OBJECTIVE:To assess the correlation of pre-operative symptoms, pre-operative diagnostic imaging for cartilage loss, and intra-operative cartilage findings in patients undergoing hip arthroscopy for femoroacetabular impingement syndrome. MATERIALS AND METHODS/METHODS:Three radiologists performed retrospective independent reviews of pre-operative MRIs in 96 hips for acetabular/femoral cartilage loss utilizing a simplified "high-low" classification and the International Cartilage Repair Society grading system. Severity of supra-foveal central femoral head cartilage loss was separately noted. Pre-operative radiographs were graded using the Tonnis and Kellgren-Lawrence systems and for central joint space narrowing. Pre-operative patient symptoms were prospectively gathered utilizing the Nonarthritic Hip Score and the modified Harris Hip Score. Intra-operatively, cartilage loss was recorded using the Outerbridge system. RESULTS: CONCLUSION/CONCLUSIONS:Despite MRI underestimation of cartilage loss, the very weak-to-weak correlation of clinical symptoms with pre-operative imaging and intra-operative findings emphasizes the importance of MRI in pre-operative evaluation.

The abscopal effect is a rare but important phenomenon in which targeted therapy of the primary tumor, mainly radiation therapy, leads to the regression of malignant cells at distant sites from the primary tumor and outside the field of treatment. Radioembolization is a developing area of interventional oncology, typically involving microscopic radioactive spheres loaded with yttrium-90. The abscopal effect on distant bone metastases has been previously reported in patients following palliative radiotherapy; however, it has also been observed with more targeted radiation treatments, such as yttrium-90, primarily outside the musculoskeletal system. Musculoskeletal radiologists should be familiar with the abscopal effect, as the indications for radiation therapy are on the rise, and recent advancements in immune therapy have resulted in the induction of the abscopal effect. Herein, we present a case of the abscopal effect in musculoskeletal metastatic disease following targeted radioembolization. We also review the literature on the abscopal effect involving metastatic bone lesions resulting from different types of cancer therapy. Finally, we present recent advancements in cancer treatment with the aim of utilizing this effect.

OBJECTIVE:To evaluate the Neuropathy Score-Reporting and Data System (NS-RADS) MRI grading system in conjunction with electrodiagnostic (EDx) testing for radial neuropathy at the elbow. MATERIALS AND METHODS/METHODS:Patients presenting between 2010 and 2023 with suspected radial neuropathy who underwent both EDx testing in the form of electromyography and nerve conduction studies and MRI within a 12-month period were evaluated. Three blinded radiologists used the NS-RADS grading system to evaluate nerve entrapment (E grades), muscle denervation (M grades) proximally within the supinator/extensor carpi radialis brevis (ECRB), and more distally within the forearm extensor muscles. These grades and the presence of lateral epicondylitis were then correlated with EDx abnormalities. RESULTS:Forty-nine participants were included. Inter-reader reliability for M grades in the forearm extensor muscles was good (ICC = 0.90 [95% CI = 0.83 - 0.94], p < 0.001), as was reliability for the supinator/ECRB muscles (ICC = 0.91 [95% CI = 0.86-0.95], p < 0.001). Inter-reader reliability for E grades was moderate (ICC = 0.83 [95% CI = 0.69-0.90], p < 0.001). Patients with positive EDx studies had a significantly different distribution of M grades for the forearm extensors and supinator/ECRB than those with negative studies (all p values < 0.001). However, overall consensus reads showed no significant difference in the distribution of E grades between patients with positive and negative EDx studies. CONCLUSION/CONCLUSIONS:Muscle grading strongly correlated with EDx positivity, with a high level of inter-reader agreement for muscle denervation-related alterations. Nerve grading, however, did not show a statistical correlation.

OBJECTIVES/OBJECTIVE:To evaluate the yield of CT-guided biopsy of 18F-piflufolastat PET avid osseous lesions in suspected prostate metastases. METHODS:Retrospective review of computed tomography guided biopsies targeting 18F-piflufolastat avid lesions on PET/CT or PET/MR performed between 2022 and 2024. Demographics, image modality, biopsy system, number of cores, lesion location, lean body mass corrected SUV (SUL) and pathology were recorded. Biopsied lesions were compared to the PROMISE (prostate cancer molecular imaging standardized evaluation) scoring system, version 2. RESULTS:Eighteen patients were included, average age 68.7 years. Lesions were defined as: ≥ 50 % sclerotic (n = 10), <50 % sclerotic (n = 7), occult (n = 0), and lytic (n = 1). A technically successful pathologic diagnosis was made in 94 % of biopsies (n = 17). Histopathological diagnosis included: metastatic prostate adenocarcinoma (n = 12), benign with fibrotic/densely sclerotic bone or normocellular bone marrow (n = 5), and metastatic non-small cell lung carcinoma (n = 1). The median SUL on PET for all patients was 7.9 (IQR 13.3), 2.6 (0.3) for benign biopsies, and 8.8 (12.5) for malignant biopsies. Major identifiable differences between biopsies yielding a metastatic versus benign diagnosis included: higher SUL (p-value = 0.03), target lesion volume (p-value = 0.01), and higher incidence of sclerotic lesions (p value = 0.003); however, multivariate analysis did not find these to be statistically significant predictors (p-value >0.05). The prostate cancer lesion biopsy positive group had significantly higher PROMISE scores than the negative group (p = 0.03). CONCLUSION/CONCLUSIONS:CT-guided biopsy of bone lesions demonstrating avidity for 18F-piflufolastat can be performed with a high diagnostic yield.

Rheumatoid arthritis is a common chronic inflammatory arthritis, primarily characterized by proliferative synovitis of the small joints of the appendicular skeleton. Rapidly evolving treatment regimens for rheumatoid arthritis patients, including conventional and biologic disease-modifying antirheumatic drugs, promise improved quality of life and prognosis. These treatments necessitate earlier clinical detection of rheumatoid arthritis, a goal that has forever changed the role of imaging in this pursuit. This review discusses the dominant imaging modalities in state-of-the-art rheumatoid arthritis management: radiography, magnetic resonance imaging, and ultrasound. It focuses on hand and wrist evaluation, with key relevant findings detected by each modality and recent evidence supporting them. Emerging techniques are also described in this discussion to understand likely future radiologic contributions to rheumatoid arthritis diagnosis and management.

PURPOSE/OBJECTIVE:The aim of this study was to assess the inter-rater reproducibility and inter-method comparability of hip alpha angle measurements on magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA) and plain radiographs in patients with femoroacetabular impingement syndrome (FAIS). METHODS:A cross-sectional study of patients who were diagnosed with symptomatic FAIS underwent preoperative MRI/MRA with axial oblique and/or radial plane imaging and had preoperative radiographs with anterior-posterior (AP), 45° Dunn and 90° Dunn views. Alpha angle measurements were performed independently by two musculoskeletal radiologists. Inter-rater reproducibility and inter-method comparability between MRI/MRA images and radiographic views were assessed using the intraclass correlation coefficient (ICC) with 95% confidence interval (CI). RESULTS:Ninety-seven patients were included of whom 93 (95.8%) received axial oblique plane images and 54 (55.6%) had radial plane MRI/MRA images. Inter-rater reproducibility was excellent (ICC > 0.9) for all planes on MRI/MRA and radiographs. MRI/MRA axial oblique images had poor (ICC 0.39, 95% CI [0.09, 0.59]), moderate (ICC 0.57, 95% CI [0.18, 0.75]) and moderate (ICC 0.64, 95% CI [0.20, 0.81]) comparability with AP, 45° Dunn and 90° Dunn, respectively. MRI/MRA radial plane images had equivocal (0 included in all CIs) comparability with AP (ICC 0.66), 45° Dunn (ICC 0.35) and 90° Dunn (ICC 0.14) radiographs. On average, alpha angle measurements were significantly higher with radial images and lower with axial oblique images, when compared to all radiographic views (p < 0.05), except axial oblique versus 45° Dunn views, where angles measured on axial oblique were significantly larger. CONCLUSION/CONCLUSIONS:Alpha angle measurements taken on axial oblique MRI/MRA images show moderate comparability to radiographic 45° Dunn and 90° Dunn views despite negative bias to measurements taken on radiographic AP and 45° Dunn view. Larger alpha angles were appreciated on MRI/MRA radial and axial oblique views compared to radiographic views supporting the inclusion of MRI/MRA alpha angle measurements to properly identify deformity. LEVEL OF EVIDENCE/METHODS:Level II.