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.

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.

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.

BACKGROUND:Studies have not explored consciousness during deep hypothermic circulatory arrest (DHCA). However, as studies in cardiac arrest have identified a spectrum of consciousness, we sought to establish the feasibility of studying consciousness during DHCA. METHODS:This was a prospective study across 10 hospitals with 36 DHCA patients undergoing thoracic aortic aneurysm repair or pulmonary endarterectomy. A tablet computer delivered audiovisual stimuli (images and names of three fruits) using headphones during each procedure as a potential test of implicit learning and explicit recall. We also established electroencephalography (EEG) and near-infrared spectroscopy (NIRS) to measure electrocortical markers of consciousness and cerebral oxygenation. Post-procedure interviews were carried out to test patients' ability to recall the audiovisual stimuli as well other explicit memories. PRIMARY OUTCOMES/METHODS:1) Feasibility of establishing tests of explicit recall and implicit learning, 2) Electroencephalography testing during DHCA. SECONDARY OUTCOMES/RESULTS:1) Signs of explicit recall of memories or implicit learning, and 2) identification of electrocortical biomarkers of consciousness during DHCA. RESULTS:Overall, 29/36 (81%) had the tablet set up. All 36 had NIRS and EEG set up, but 9 (25%) had useable EEG data, and 23 (66%) NIRS data. Delta EEG waves were observed during circulatory arrest in 3/9 (33%) patients, while 1/9 (11%) had theta waves just prior to circulatory arrest. All others showed isoelectric pattern. 35/36 (97%) agreed to follow up interviews. None had explicit recall of the names of the three fruits, but 3/36 (9%) correctly guessed them as a potential sign of implicit learning and 3 (9%) recalled other memories including events around the procedure and themes consistent with a recalled experience of death. CONCLUSIONS:A spectrum of consciousness and awareness, including signs of implicit learning and electrocortical biomarkers of consciousness may be present during DHCA, despite absence of visible signs of consciousness. This can be further used to help explain the negative psychological outcomes that cardiac arrest survivors face.

Ultrasound (US) is a valuable tool in the evaluation of arthritis both for diagnosis and treatment response. Pertinent findings such as joint effusions, synovitis, bursitis, bone erosions, tenosynovitis, and enthesitis can all be readily evaluated sonographically. In this article, we describe specific considerations in the US evaluation of rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis, crystalline arthritis (gout, calcium pyrophosphate deposition disease, and hydroxyapatite deposition disease), septic arthritis, and osteoarthritis with attention to certain differentiating features. The potential role of US in the diagnosis of specific arthritides is discussed, together with an overview of newer technologies and future directions.

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.

This article comprehensively reviews current imaging concepts in spinal infection with primary focus on infectious spondylodiscitis (IS) as well as the less common entity of facet joint septic arthritis (FSA). This review encompasses the multimodality imaging appearances (radiographs, CT, MRI, and nuclear imaging) of spinal infection-both at initial presentation and during treatment-to aid the radiologist in guiding diagnosis and successful management. We discuss the pathophysiology of spinal infection in various patient populations (including the non-instrumented and postoperative spine) as well as the role of imaging-guided biopsy. We also highlight several non-infectious entities that can mimic IS (both clinically and radiologically) that should be considered during image interpretation to avoid misdiagnosis. These potential mimics include the following: Modic type 1 degenerative changes, acute Schmorl's node, neuropathic spondyloarthropathy, radiation osteitis, and inflammatory spondyloarthropathy (SAPHO syndrome).

OBJECTIVE:To describe the morphologic sonographic appearances and frequency of the "halo sign" in the setting of fat necrosis on shear wave elastography (SWE). METHODS:Patients with clinically suspected fat necrosis were prospectively scanned using SWE in addition to standard gray-scale and Doppler images. Cases were qualitatively grouped into one of three sonographic appearances: focal hypoechoic lesion with increased internal tissue stiffness ("focal stiffness"), focal hypoechoic lesion with isoechoic or hyperechoic periphery demonstrating increased tissue stiffness relative to the central hypoechoic lesion ("halo stiffness"), heterogeneously echogenic lesion with diffusely increased stiffness ("heterogeneous stiffness"). RESULTS:Exactly 19 patients met inclusion criteria (female n = 14; male n = 5). Shear wave velocities were recorded and retrospectively evaluated. The mean clinical follow-up was 11.4 months (range 3.0-25.5). Lesions demonstrated higher average tissue stiffness than background tissue (overall mass shear wave velocity 3.26 m/s, background 1.42 m/s, P < .001; lesion Young's modulus 40.85 kPa vs background 7.22 kPa, P < .001). The halo sign was identified in 10/19 (55%) patients. CONCLUSION/CONCLUSIONS:The halo sign is a potentially useful sign in the setting of fat necrosis seen in the majority of clinically suspected cases.