Faculty Bibliography

PURPOSE/OBJECTIVE:The aim of this study was to assess changing Medicare volumes of, and coverage for, secondary interpretations of diagnostic imaging examinations stratified by modality and body region service families. METHODS:Medicare Physician/Supplier Procedure Summary Master Files for 2003 to 2016 were obtained. Aggregate Part B fee-for-service claims frequency and payment data were isolated for noninvasive diagnostic imaging and stratified by service family. Using published Medicare payment rules, secondary interpretations were identified as studies billed using both modifiers 26 and 77. Billed and denied services volumes were calculated and compared across modality and body region service families. RESULTS:Seven service families showed a compound annual growth rate from 2003 to 2016 of >20% (an additional 12 service families, >10% growth). For select high-volume service families (chest radiography and fluoroscopy [R&F], brain MRI, and abdominal and pelvic CT), relative growth in billed secondary interpretation services exceeded that for primary interpretations. In 2016, body region and modality service families with the most billed secondary interpretations were chest R&F (674,124), abdominal and pelvic R&F (65,566), brain CT (45,642), extremity R&F (34,560), abdominal and pelvic CT (14,269), and chest CT (10,914). All service families had secondary interpretation denial rates <25% in 2016 (15 service families, <10%). CONCLUSIONS:Among Medicare beneficiaries, the frequency of billed secondary interpretation services for diagnostic imaging services increased from 2003 to 2016 across a broad range of modalities and body regions, often dramatically. Payment denial rates were consistently low across service families. As CMS continues to seek input on appropriate coverage for these services, these findings suggest increasing clinical demand for and payer acceptance of these value-added radiologist services.

Purpose To retrospectively assess whether there is an association between screening mammography and the use of a variety of preventive services in women who are enrolled in Medicare. Materials and Methods U.S. Medicare claims from 2010 to 2014 Research Identifiable Files were reviewed to retrospectively identify a group of women who underwent screening mammography and a control group without screening mammography in 2012. The screened group was divided into positive versus negative results at screening, and the positive subgroup was divided into false-positive and true-positive findings. Multivariate logistic regression models and inverse probability of treatment weighting were used to examine the relationship between screening status and the probabilities of undergoing Papanicolaou test, bone mass measurement, or influenza vaccination in the following 2 years. Results The cohort consisted of 555 705 patients, of whom 185 625 (33.4%) underwent mammography. After adjusting for patient demographics, comorbidities, geographic covariates, and baseline preventive care, women who underwent index screening mammography (with either positive or negative results) were more likely than unscreened women to later undergo Papanicolaou test (odds ratio [OR], 1.49; 95% confidence interval: 1.40, 1.58), bone mass measurement (OR, 1.70; 95% confidence interval: 1.63, 1.78), and influenza vaccine (OR, 1.45; 95% confidence interval: 1.37, 1.53). In women who had not undergone these preventive measures in the 2 years before screening mammography, use of these three services after false-positive findings at screening was no different than after true-negative findings at screening. Conclusion In beneficiaries of U.S. Medicare, use of screening mammography was associated with higher likelihood of adherence to other preventive guidelines, without a negative association between false-positive results and cervical cancer screening.

PURPOSE/OBJECTIVE:To conduct a meta-analysis of studies investigating discrepancy rates and clinical impact of imaging secondary interpretations and to identify factors influencing these rates. METHODS:EMBASE and PubMed databases were searched for original research investigations reporting discrepancy rates for secondary interpretations performed by radiologists for imaging examinations initially interpreted at other institutions. Two reviewers extracted study information and assessed study quality. Meta-analysis was performed. RESULTS:Twenty-nine studies representing a total of 12,676 imaging secondary interpretations met inclusion criteria; 19 of these studies provided data specifically for oncologic imaging examinations. Primary risks of bias included availability of initial interpretations, other clinical information, and reference standard before the secondary interpretation. The overall discrepancy rate of secondary interpretations compared with primary interpretations was 32.2%, including a 20.4% discrepancy rate for major findings. Secondary interpretations were management changing in 18.6% of cases. Among discrepant interpretations with an available reference standard, the secondary interpretation accuracy rate was 90.5%. The overall discrepancy rates by examination types were 28.3% for CT, 31.2% for MRI, 32.7% for oncologic imaging, 43.8% for body imaging, 39.9% for breast imaging, 34.0% for musculoskeletal imaging, 23.8% for neuroradiologic imaging, 35.5% for pediatric imaging, and 19.7% for trauma imaging. CONCLUSION/CONCLUSIONS:Most widely studied in the context of oncology, imaging secondary interpretations commonly result in discrepant interpretations that are management changing and more accurate than initial interpretations. Policymakers should consider these findings as they consider the value of, and payment for, secondary imaging interpretations.

Purpose: To compare the effectiveness of standard treatment using partial nephrectomy and personalized management strategies for small renal tumors using a simulation model.
Material(s) and Method(s): A decision-analytic model was constructed to compare life expectancy of management strategies for small renal tumors using: (1) uniform treatment with partial nephrectomy; or personalized options incorporating (2) percutaneous ablation; (3) biopsy, with triage of renal cell carcinoma (RCC) to nephron-sparing therapy; (4) watchful waiting for growth; and (5) MRI-based selection of papillary RCC for watchful waiting. The model included patient age, gender, chronic kidney disease (CKD) stage, renal functional decline specific to treatment type, comorbidities, benign and malignant tumors, RCC subtypes, and differential risks of cancer progression. Decisionmaking based on histologic subtype from biopsy was tested in sensitivity analysis.
Result(s): Partial nephrectomy was favored in patients of all ages with normal renal function. Otherwise, personalized strategies improved life expectancy compared with partial nephrectomy. The favorability of personalized therapy depended upon CKD stage, tumor anatomy and comorbidities. For example, patients with CKD stages 2 or 3a and moderate or high tumor anatomic complexity were most effectively treated with MRI-based management when they had no comorbidities (+ 2.57 years for MRI vs. partial nephrectomy in CKD 3a, Nephrometry Score 10), but with Charlson Comorbidity Index >=1, biopsy or watchful waiting for growth were most effective. Biopsy-based management became most effective in multiple patient subcategories when histologic subtype guided treatment selection.
Conclusion(s): Personalized treatment selection for small renal tumors likely improves life expectancy for patients with abnormal renal function

In the management of epithelial ovarian cancers, imaging is used for cancer detection and staging, both before and after initial treatment. The decision of whether to pursue initial cytoreductive surgery for ovarian cancer depends in part on accurate staging. Contrast-enhanced CT of the abdomen and pelvis (and chest where indicated) is the current imaging modality of choice for the initial staging evaluation of ovarian cancer. Fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT and MRI may be appropriate for problem-solving purposes, particularly when lesions are present on CT but considered indeterminate. In patients who achieve remission, clinical suspicion for relapse after treatment prompts imaging evaluation for recurrence. Contrast-enhanced CT is the modality of choice to assess the extent of recurrent disease, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT is also usually appropriate, as small metastatic foci may be identified. If imaging or clinical examination confirms a recurrence, the extent of disease and timing of disease recurrence then determines the choice of treatments, including surgery, chemotherapy, and radiation therapy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

OBJECTIVE: The purpose of this study is to assess differences in patient distress, risk perception, and treatment preferences for incidental renal findings with descriptive versus combined descriptive and numeric graphical risk information. MATERIALS AND METHODS: A randomized survey study was conducted for adult patients about to undergo outpatient imaging studies at a large urban academic institution. Two survey arms contained either descriptive or a combination of descriptive and numeric graphical risk information about three hypothetical incidental renal findings at CT: 2-cm (low risk) and 5-cm (high risk) renal tumors and a 2-cm (low risk) renal artery aneurysm. The main outcomes were patient distress, perceived risk (qualitative and quantitative), treatment preference, and valuation of lesion discovery. RESULTS: Of 374 patients, 299 participated (79.9% response rate). With inclusion of numeric and graphical, rather than only descriptive, risk information about disease progression for a 2-cm renal tumor, patients reported less worry (3.56 vs 4.12 on a 5-point scale; p < 0.001) and favored surgical consultation less often (29.3% vs 46.9%; p = 0.003). The proportion choosing surgical consultation for the 2-cm renal tumor decreased to a similar level as for the renal artery aneurysm with numeric risk information (29.3% [95% CI, 21.7-36.8%] and 27.9% [95% CI, 20.5-35.3%], respectively). Patients overestimated the absolute risk of adverse events regardless of risk information type, but significantly more so when given descriptive information only, and valued the discovery of lesions regardless of risk information type (range, 4.41-4.81 on a 5-point scale). CONCLUSION: Numeric graphical risk communication for patients about incidental renal lesions may facilitate accurate risk comprehension and support patients in informed decision making.

Purpose To investigate whether assessment of bone strength with quantitative computed tomography (CT) in combination with dual-energy x-ray absorptiometry (DXA) is cost-effective as a screening tool for osteoporosis in postmenopausal women. Materials and Methods A state-transition microsimulation model of osteoporosis for postmenopausal women aged 55 years or older was developed with a lifetime horizon and U.S. societal perspective. All model inputs were derived from published literature. Three strategies were compared: no screening, DXA with T score-dependent rescreening intervals, and a combination of DXA and quantitative CT with different intervals (3, 5, and 10 years) at different screening initiation ages (55-65 years). Oral bisphosphonate therapy was started if DXA hip T scores were less than or equal to -2.5, 10-year risk for hip fracture was greater than 3% (World Health Organization Fracture Risk Assessment Tool score, or FRAX), 10-year risk for major osteoporotic fracture was greater than 20% (FRAX), quantitative CT femur bone strength was less than 3000 N, or occurrence of first fracture (eg, hip, vertebral body, wrist). Outcome measures were incremental cost-effectiveness ratios (ICERs) in 2015 U.S. dollars per quality-adjusted life year (QALY) gained and number of fragility fractures. Probabilistic sensitivity analysis was also performed. Results The most cost-effective strategy was combined DXA and quantitative CT screening starting at age 55 with quantitative CT screening every 5 years (ICER, $2000 per QALY). With this strategy, 12.8% of postmenopausal women sustained hip fractures in their remaining life (no screening, 18.7%; DXA screening, 15.8%). The corresponding percentages of vertebral fractures for DXA and quantitative CT with a 5-year interval, was 7.5%; no screening, 11.1%; DXA screening, 9%; for wrist fractures, 14%, 17.8%, and 16.4%, respectively; for other fractures, 22.6%, 30.8%, and 27.3%, respectively. In probabilistic sensitivity analysis, DXA and quantitative CT at age 55 years with quantitative CT screening every 5 years was the best strategy in more than 90% of all 1000 simulations (for thresholds of $50 000 per QALY and $100 000 per QALY). Conclusion Combined assessment of bone strength and bone mineral density is a cost-effective strategy for osteoporosis screening in postmenopausal women and has the potential to prevent a substantial number of fragility fractures. (c) RSNA, 2017 Online supplemental material is available for this article.

There has been much interest in the identification of a successful ovarian cancer screening test, in particular, one that can detect ovarian cancer at an early stage and improve survival. We reviewed the currently available data from randomized and observational trials that examine the role of imaging for ovarian cancer screening in average-risk and high-risk women. We found insufficient evidence to recommend ovarian cancer screening, when considering the imaging modality (pelvic ultrasound) and population (average-risk postmenopausal women) for which there is the greatest available published evidence; randomized controlled trials have not demonstrated a mortality benefit in this setting. Screening high-risk women using pelvic ultrasound may be appropriate in some clinical situations; however, related data are limited because large, randomized trials have not been performed in this setting. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Purpose To analyze the cost effectiveness of the American Society for Gastrointestinal Endoscopy (ASGE) risk stratification guidelines versus magnetic resonance (MR) cholangiopancreatography-based treatment of patients with possible choledocholithiasis. Materials and Methods A decision-analytic model was constructed to compare cost and effectiveness of three diagnostic strategies for gallstone disease with possible choledocholithiasis: noncontrast MR cholangiopancreatography, contrast material-enhanced MR imaging/MR cholangiopancreatography, and ASGE risk stratification guidelines for diagnostic evaluation recommending endoscopy (high risk), MR cholangiopancreatography (intermediate risk), or no test (low risk). Analysis was performed from a U.S. health system perspective over 1-year and lifetime horizons. The model accounted for benign and malignant causes of biliary obstruction and procedural complications. Cost information was based on Medicare reimbursements. Sensitivity analysis assessed the impact of parameter variability on model results. Results Noncontrast MR cholangiopancreatography was most cost-effective in 45-55-year-old patients (less than $100 000 per quality-adjusted life-year [QALY] gained), while contrast-enhanced MR imaging was favored in younger adults. Risk-stratified testing was less costly than MR cholangiopancreatography, with long-term savings of $1870 and $2068 versus noncontrast and contrast-enhanced MR cholangiopancreatography, respectively, but was also less effective (-0.1814, -0.1831 QALY, respectively). The lifetime incremental cost per QALY for noncontrast MR cholangiopancreatography was $10 311. Contrast-enhanced MR imaging was favored with pretest probabilities of biliary stricture or malignancy 0%-73% for patients aged 20-44 years. For patients older than 55 years, ASGE guidelines maximized QALYs at the lowest cost. Conclusion Although adults older than 55 years of age are optimally evaluated by using ASGE guidelines, younger patients suspected of having acute biliary obstruction likely benefit from MR cholangiopancreatography rather than risk-stratified diagnostic imaging because of improved detection of choledocholithiasis and alternative causes of biliary obstruction. (c) RSNA, 2017 Online supplemental material is available for this article.