Faculty Bibliography

Background Osteoporosis is underdiagnosed and undertreated, prompting the exploration of opportunistic screening using CT and artificial intelligence. Purpose To develop a reproducible convolutional neural network to automatically identify a three-dimensional (3D) region of interest (ROI) in trabecular bone, develop a correction method to normalize attenuation values across different CT protocols and scanner models, and establish thresholds for diagnosing osteoporosis in a large diverse population. Materials and Methods In this retrospective study, a deep learning-based method was developed to automatically quantify trabecular attenuation of the thoracic and lumbar spine on CT images with use of a 3D ROI. A statistical method was developed to adjust for different tube voltages and scanner models. Normative values and diagnostic thresholds for trabecular attenuation of the spine for osteoporosis were established based on the reported prevalence of osteoporosis by the World Health Organization. Differences between groups were assessed using the Student t test. Results A total of 538 946 CT examinations from 283 499 patients (mean age, 65 years ± 15 [SD]; 145 021 [51.2%] female; 157 457 [55.5%] White patients) were analyzed, representing 43 scanner models and six different tube voltages. The attenuation values at 80 kVp and 120 kVp differed by 23%, and different scanner models resulted in differences in values of less than 10%. The automated ROI placement of 1496 vertebrae was validated by manual radiologist review and demonstrated greater than 99% agreement. Trabecular attenuation was greater in young women (age <50 years) than in young men (P < .001) and decreased with age, with a steeper decline in postmenopausal women. In patients older than 50 years, trabecular attenuation was greater in male than in female patients (P < .001). Trabecular attenuation was highest in Black patients, followed by Asian patients, and lowest in White patients (P < .001). Conclusion Deep learning-based automated opportunistic osteoporosis screening can identify patients with low bone mineral density using CT scans obtained for clinical purposes with use of different scanners and protocols. © RSNA, 2025 Supplemental material is available for this article. See also the editorial by Feuerriegel and Sutter in this issue.

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.

BACKGROUND:Abdominal computed tomography (CT) is commonly performed in adults. Abdominal aortic calcification (AAC) can be visualized and quantified using artificial intelligence (AI) on CTs performed for other clinical purposes (opportunistic CT). We sought to investigate the value of AI-enabled AAC quantification as a predictor of coronary artery disease and its association with cardiovascular events. METHODS:A fully automated AI algorithm to quantify AAC from the diaphragm to aortic bifurcation using the Agatston score was retrospectively applied to a cohort of patient that underwent both non-contrast abdominal CT for routine clinical care and cardiac CT for coronary artery calcification (CAC) assessment. Subjects were followed for a median of 36 months for major adverse cardiovascular events (MACE, composite of death, myocardial infarction [MI], ischemic stroke, coronary revascularization) and major coronary events (MCE, MI or coronary revascularization). RESULTS:Our cohort included 3599 patients (median age 60 years, 62% male, 74% white) with an evaluable abdominal and cardiac CT. There was a positive correlation between presence and severity of AAC and CAC (r=0.56, P<0.001). AAC showed excellent discriminatory power for detecting or ruling out any CAC (AUC for PREVENT risk score 0.701 [0.683 to 0.718]; AUC for PREVENT plus AAC 0.782 [0.767 to 0.797]; P<0.001). There were 324 MACE, of which 246 were MCE. Following adjustment for the 10-year cardiovascular disease PREVENT score, the presence of AAC was associated with a significant risk of MACE (adjHR 2.26, 95% CI 1.67-3.07, P<0.001) and MCE (adjHR 2.58, 95% CI 1.80-3.71, P<0.001). A doubling of the AAC score resulted in an 11% increase in the risk of MACE and a 13% increase in the risk of MCE. CONCLUSIONS:Using opportunistic abdominal CTs, assessment of AAC using a fully automated AI algorithm, predicted CAC and was independently associated with cardiovascular events. These data support the use of opportunistic imaging for cardiovascular risk assessment. Future studies should investigate whether opportunistic imaging can help guide appropriate cardiovascular prevention strategies.

Diversity, equity, and inclusion (DEI) is important for delivering high-quality, culturally competent care and ensuring equal access to resources and opportunities in healthcare. However, the implementation of DEI has been met with unique challenges and successes across the globe. The International Skeletal Society (ISS), a multidisciplinary musculoskeletal society, made a conscious effort to promote DEI. This article discusses advantages and controversies of DEI approaches, DEI initiatives implemented by the ISS, and experiences of the ISS DEI committee members from their respective continents. The ISS DEI committee implemented educational webinars with expert panel discussions, revising membership criteria and policies for enhancing inclusiveness, advising on programing and speakers for the annual meeting, and fostering mentorship. From a global perspective, in North America, DEI has improved health outcomes and patient care, but anti-DEI legislation has posed significant challenges. Europe relies on international recruitment but faces challenges in staff retention. South America's cultural diversity necessitates culturally sensitive approaches, but discussions about DEI are scarce, and gender inequalities persist in leadership. In Africa, DEI principles are underdeveloped, with limited engagement among stakeholders. In Asia, DEI is emerging, with more women being appointed to faculty positions and leadership roles in academic societies. The implementation of meaningful DEI initiatives requires long-term institutional buy-in and the global participation and commitment of employees and institutional leaders at all levels.

OBJECTIVE:To retrospectively validate the diagnostic power of attenuation values on chest and abdomen/pelvis CECTs, together and separately, compared with dual-energy X-ray absorptiometry (DEXA)-determined osteoporosis diagnoses, and to determine thresholds for accurate osteoporosis diagnosis. MATERIALS AND METHODS/METHODS:Subjects were identified using the electronic health record. Included patients received DEXA and CECT scans within 60 days of each other. Patients were excluded if taking osteoporosis medication, undergoing dialysis, receiving hormone or cancer therapy, had a history of cancer, osseous metastases, fractures, or compressions. Minimum, mean, and maximum CECT attenuation values of L1 trabecular bone axial cross-sections were measured by a non-physician in Hounsfield units (HUs) using an elliptical region of interest (ROI) tool. DEXA diagnoses were dichotomized as positive (osteoporosis) or negative (osteopenia/normal). The area under the receiver-operator characteristic curves (AUCs) were compared to identify ideal CECT attenuation thresholds. RESULTS:Two hundred nineteen subjects (mean age 66 ± 0.6 [range 35-92]; 196 (89%) females and 23 (11%) males) were included for analysis. Thirty-one (14%) subjects were positive and 188 (86%) were negative for osteoporosis. Minimum, mean, and maximum combined chest and abdomen/pelvis attenuation values demonstrated AUCs of 0.75 (95% CI 0.67-0.84), 0.931 (95% CI 0.88-0.99), and 0.82 (95% CI 0.73-0.90). The optimal mean attenuation threshold for osteoporosis diagnosis was 120 HU (84% sensitive, 90% specific). There was no statistical difference in diagnostic power between mean attenuation values of chest and abdomen/pelvis CECTs. CONCLUSION/CONCLUSIONS:CECT mean attenuation values of either chest or abdomen/pelvis CECTs could be used as appropriate thresholds in screening for osteoporosis.

RATIONALE AND OBJECTIVES/OBJECTIVE:Multiple modalities exist for diagnosing ulnar neuropathy at the elbow (UNE), including electrodiagnostic testing (EDX), ultrasound (US), and magnetic resonance imaging (MRI), with no consensus on the optimal strategy. This study's objective was to determine the most cost-effective diagnostic strategy in patients with suspected UNE. MATERIALS AND METHODS/METHODS:We developed a decision analytic model from the U.S. healthcare perspective over a 1-year time horizon. Our hypothetical population comprised 56-year-old males with medial elbow pain and/or paresthesias radiating to the hand, without weakness. We compared incremental cost-effectiveness and total net monetary benefit (NMB) of single-modality strategies (EDX, US, MRI) and multimodality strategies (combinations of US/MRI, EDX/US, EDX/MRI). Input probabilities and utility values were obtained from the literature, and costs from Centers for Medicaid & Medicare Services and institutional data. The primary outcome was quality-adjusted life years (QALYs). Willingness-to-pay threshold was $100,000. RESULTS:The diagnostic strategy utilizing US first, followed by MRI, was favored with the highest total QALYs, .935, and total NMB, $92,667. EDX and US single-modality strategies were less favorable, with lower total QALYs, .894 and .906, respectively, and lower total NMB, $88,866 and $90,022. Other diagnostic strategies were excluded by absolute or extended dominance. One-way sensitivity analyses found model results sensitive to the utility of UNE recovery, but otherwise robust over a range of costs/probabilities. CONCLUSION/CONCLUSIONS:Our cost-effectiveness analysis suggests an initial US, then MRI is the most cost-effective strategy in the workup of patients with suspected UNE.

OBJECTIVE:To determine the cost-effectiveness of different imaging modalities for initial detection of multiple myeloma (MM)-defining bone lesions. METHODS:A Markov model from the health care system perspective for patients with MGUS was used to evaluate the incremental cost-effectiveness of five imaging techniques: skeletal survey (SS), low-dose computed tomography (LDCT), positron emission computed tomography (PETCT), and whole-body magnetic resonance imaging (WBMRI) with and without diffusion (DIFF). Model inputs, including probabilities, utilities, and costs were obtained from comprehensive literature review. Costs were estimated in 2024 U.S. dollars, effectiveness was measured in quality adjusted life years (QALYs), willingness-to-pay (WTP) threshold was set to $100,000/QALY, and timeframe of the simulation was 20 years. Model analyses included Monte Carlo microsimulation and probabilistic sensitivity analysis (PSA). RESULTS:The most cost-effective imaging strategy was dependent on the number of patient risk factors for progression from MGUS to myeloma. At a WTP threshold of $100,000, for patients with no risk factors for progression, LDCT amassed the greatest net monetary benefit (NMB) ($1,030,913.57) while incurring the second lowest costs ($44,870.73). For patients with 1 or 2 risk factors for progression, WBMRI + DIFF amassed the greatest NMB (1 risk factor: $802,637.30, 2 risk factors: $664,430.36). WBMRI and PETCT were absolutely dominated in all cases. PSA also found that the most cost-effective strategy was dependent on the WTP threshold. CONCLUSION/CONCLUSIONS:Our model suggests that LDCT and WBMRI + DIFF can be the most cost-effective imaging strategies for the initial diagnosis of MM in patients, depending on the number of risk factors for progression.

PURPOSE/OBJECTIVE:The aim of this study was to determine the potential impact of opportunistic CT bone density screening in terms of increasing screening rates and cost avoidance. METHODS:The analytic dataset was extracted from the Medicare 5% Research Identifiable Files (2015-2022). All dual-energy x-ray absorptiometry (DEXA) procedures and contrast and/or noncontrast CT procedures of pertinent body regions were identified using Current Procedural Terminology codes. Outcomes of interest included osteoporosis screening imaging and fragility fractures of the hip or spine. Potential annual cost avoidance was calculated. RESULTS:In total, 2,897,040 beneficiaries were identified for analysis, of whom 584,391 beneficiaries (20.2%) underwent DEXA and 658,703 beneficiaries (22.7%) did not undergo DEXA but did undergo at least one CT examination that included the L1 vertebral body, 446,706 (67.8%) without and 211,997 (32.2%) with contrast. In the noncontrast and contrast CT groups, there were 2,766 (0.6%) and 613 (0.3%) hip and 23,889 (5.3%) and 5,222 (2.5%) spine fragility fractures within 1 year of CT. The osteoporosis screening rate would increase by 76% using only noncontrast CT studies and by 113% using all CT studies. If only noncontrast CT was used to identify osteoporosis and treatment was successfully implemented in 100% of eligible beneficiaries, this study population would see a medical cost avoidance in excess of $17 million. If any CT was used, potential annual cost avoidance for this study's population would be nearly $100 million and $2.5 billion for all 2023 Medicare fee-for-service beneficiaries. CONCLUSIONS:Implementing opportunistic CT bone density screening could potentially have a substantial patient care and economic impact.