Faculty Bibliography

Opportunistic screening leverages existing imaging examinations performed for unrelated routine clinical indications to systematically extract quantitative biomarkers. Artificial intelligence tools have made deployment at scale increasingly feasible. However, the pathway from a validated algorithm to a functioning clinical program remains poorly defined, and prospective implementation at scale is uncommon. Successful deployment requires coordinated engagement from radiologists, information technology and operational teams, and clinical care teams, each facing distinct decisions that determine whether a program functions reliably and delivers patient benefit. This article presents a practical framework for opportunistic screening implementation organized around these three stakeholder groups. We apply this framework to opportunistic CT osteoporosis screening, drawing on our experience developing such a program at a large academic medical center. The framework presented is intended to be broadly applicable across opportunistic screening applications as the field moves from algorithmic validation toward clinical translation.

With the rapid growth of the use of computed tomography, advances in artificial intelligence enable opportunistic screening, the systematic extraction of clinically meaningful biomarkers from imaging scans performed for other indications. Modeling studies demonstrate that opportunistic screening can be highly cost effective by enabling early intervention and preventing complications such as osteoporotic fractures. Musculoskeletal radiologists are uniquely positioned to contribute to this paradigm shift because routine examinations frequently include vertebrae, skeletal muscle, adipose tissue, and vasculature, all structures that provide quantitative data on bone mineral density, sarcopenia, adiposity, and cardiovascular risk. However, widespread implementation faces challenges, such as the need for prospective outcomes data, normative reference standards, workflow integration, and clear pathways for clinical follow-up. This review examines the rationale, technical foundations, key applications, and challenges for opportunistic screening in musculoskeletal radiology.

OBJECTIVE:To evaluate the cost-effectiveness of opportunistic CT for sarcopenia screening compared with standard-of-care clinical screening methods, using a decision-analytic model based on quality-adjusted life years (QALYs) and healthcare costs. MATERIALS AND METHODS/METHODS:We developed a decision-analytic model simulating a hypothetical cohort of 70-year-old male patients at risk for sarcopenia over a 3-year time horizon from a US healthcare system perspective. The model compared two screening strategies: standard-of-care clinical evaluation per EWGSOP2 guidelines (physical exam + DXA evaluation of lean mass) and opportunistic CT as measures of muscle mass and quality. Model inputs-including screening sensitivities/specificities, costs, utility values, and probabilities of cardiovascular complications-were derived from published literature. Incremental cost-effectiveness ratio (ICER) and net monetary benefit (NMB) were calculated, and sensitivity analyses were performed to assess the robustness of findings across variable inputs. RESULTS:Opportunistic CT was the favored strategy, with lower costs ($845 vs. $1,295), comparable effectiveness (0.87 QALYs), and higher net monetary benefit ($86,037 vs. $85,588) relative to the standard-of-care strategy. The standard-of-care strategy's ICER was $47.7 million per QALY, exceeding our willingness-to-pay threshold of $100,000. Probabilistic sensitivity analysis across 100,000 simulations demonstrated that opportunistic CT was favored across all tested willingness-to-pay thresholds up to $200,000. CONCLUSION/CONCLUSIONS:Opportunistic CT is a cost-effective strategy for sarcopenia screening, offering similar effectiveness at a lower cost compared to the standard-of-care approach. By leveraging existing imaging studies, opportunistic CT screening has the potential to enhance early detection and decrease the underdiagnosis of sarcopenia while also reducing the burden of additional DXA scans and clinical visits.

OBJECTIVE:To retrospectively compare the follow-up imaging recommendation rate in patients who underwent an abdominopelvic PCCT, dual-source dual-energy CT (DECT), or single-energy CT (SECT). METHODS:A retrospective PACS search identified all outpatient contrast-enhanced abdominal PCCT, DECT, and SECT from 4/11/2022-10/14/2024. PCCT and DECT examinations without virtual noncontrast and iodine map images in PACS were excluded. All radiology reports were reviewed for follow-up imaging recommendations and reason. Follow-up imaging recommendation rates were compared across all three scanner groups and pairwise between each scanner type. The projected cost savings related to avoided follow-up recommendations with PCCT compared with SECT was calculated using the average Medicare reimbursement for each potential follow-up examination. RESULTS:16,065 examinations (median(IQR) age: 66(54-76) years; 8,433 females (52%)) including 8,246 PCCT, 3,988 DECT, and 3,831 SECT were included. Follow-up imaging was recommended in 8.1% (671/8,246) of PCCT, 8.7% (347/3,988) of DECT, and 13% (517/3,831) of SECT (p < .001). MRI was recommended in 5.2% (430/8,246) of PCCT, 4.2% (166/3,988) of DECT, and 6.4% (245/3,831) of SECT (p < .001). CT was recommended in 2.0% (168/8,246) of PCCT, 3.9% (155/3,988) of DECT, and 5% (193/3,831) of SECT (p < .001). Ultrasound was recommended in 1.4% (114/8,246) of PCCT, 1.2% (48/3,988) of DECT, and 2.7% (104/3,831) of SECT (p < .001). The total estimated cost savings of avoided subsequent imaging examinations with abdominopelvic PCCT compared with SECT was $32,904 for MRI, $71,085 for CT, and $10,888 for ultrasound, with $114,877 overall projected savings. CONCLUSION/CONCLUSIONS:There were significantly reduced follow-up imaging recommendations after abdominopelvic PCCT and DECT than SECT, with projected cost savings.

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.

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.