Longitudinal evolution of CT and MRI LI-RADS v2014 category 1, 2, 3, and 4 observations.

OBJECTIVES: This study assesses the risk of progression of Liver Imaging Reporting and Data System (LI-RADS) categories, and the effects of inter-exam changes in modality or radiologist on LI-RADS categorization. METHODS: Clinical LI-RADS v2014 CT and MRI exams at our institution between January 2014 and September 2017 were retrospectively identified. Untreated LR-1, LR-2, LR-3, and LR-4 observations with at least one follow-up exam were included. Three hundred and seventy-two observations in 214 patients (149 male, 65 female, mean age 61 ± 10 years) were included during the study period (715 exams total). Cumulative incidence curves for progression to malignant LI-RADS categories (LR-5 or LR-M) and to LR-4 or higher were generated for each index category and compared using log-rank tests with a resampling extension. Relationships between inter-exam changes in LI-RADS category and modality or radiologist, adjusted for inter-exam time intervals, were modeled using mixed effect logistic regressions. RESULTS: Median inter-exam follow-up interval and total follow-up duration were 123 and 227 days, respectively. Index LR-1, LR-2, LR-3, and LR-4 differed significantly in their cumulative incidences of progression to malignant categories (p < 0.0001), which were 0%, 2%, 7%, and 32% at 6 months, respectively. Index LR-1, LR-2, and LR-3 differed significantly in cumulative incidences of progression to LR-4 or higher (p = 0.003). MRI-MRI exam pairs had more stable LI-RADS categorization compared to CT-CT (OR = 0.460, p = 0.0018). CONCLUSIONS: LI-RADS observations demonstrate increasing risk of progression to malignancy with increasing category ranging from 0% for LR-1 to 32% for LR-4 at 6 months. Inter-exam modality changes are associated with LI-RADS category changes. KEY POINTS: • While the majority of LR-2 observations remain stable over long-term follow-up, LR-3 and especially LR-4 observations have a higher risk for category progression. • Category transitions between sequential exams using different modalities (CT vs. MRI) may reflect modality differences rather than biological change. MRI, especially with the same type of contrast agent, may provide the most reproducible categorization, although this needs additional validation. • In a clinical practice setting, in which radiologists refer to prior imaging and reports, there was no significant association between changes in radiologist and changes in LI-RADS categorization.

Hepatic steatosis and reduction in steatosis following bariatric weight loss surgery differs between segments and lobes.

OBJECTIVES: The purpose of this study was to (1) evaluate proton density fat fraction (PDFF) distribution across liver segments at baseline and (2) compare longitudinal segmental PDFF changes across time points in adult patients undergoing a very low-calorie diet (VLCD) and subsequent bariatric weight loss surgery (WLS). METHODS: We performed a secondary analysis of data from 118 morbidly obese adult patients enrolled in a VLCD-WLS program. PDFF was estimated using magnitude-based confounder-corrected chemical-shift-encoded (CSE) MRI in each hepatic segment and lobe at baseline (visit 1), after completion of VLCD (visit 2), and at 1, 3, and 6 months (visits 3-5) following WLS. Linear regressions were used to estimate the rate of PDFF change across visits. Lobar and segmental rates of change were compared pairwise. RESULTS: Baseline PDFF was significantly higher in the right lobe compared to the left lobe (p < 0.0001). Lobar and segmental PDFF declined by 3.9-4.5% per month between visits 1 and 2 (preoperative period) and by 4.3-4.8% per month between visits 1 and 3 (perioperative period), but no significant pairwise differences were found in slope between segments and lobes. For visits 3-5 (postoperative period), lobar and segmental PDFF reduction was much less overall (0.4-0.8% PDFF per month) and several pairwise differences were significant; in each case, a right-lobe segment had greater decline than a left-lobe segment. CONCLUSIONS: Baseline and longitudinal changes in fractional fat content in the 5-month postoperative period following WLS vary across segments, with right-lobe segments having higher PDFF at baseline and more rapid reduction in liver fat content. KEY POINTS: • Baseline and longitudinal changes in liver fat following bariatric weight loss surgery vary across liver segments. • Methods that do not provide whole liver fat assessment, such as liver biopsy, may be unreliable in monitoring longitudinal changes in liver fat following weight loss interventions.

Housing and Food Insecurity, Care Access, and Health Status Among the Chronically Ill: An Analysis of the Behavioral Risk Factor Surveillance System.

BACKGROUND: The proportion of the United States population with chronic illness continues to rise. Understanding the determinants of quality of care-particularly social determinants-is critical to the provision of care in this population. OBJECTIVE: To estimate the prevalence of housing and food insecurity among persons with common chronic conditions and to assess the independent effects of chronic illness and sociodemographic characteristics on (1) housing and food insecurity, and (2) health care access hardship and health status. DESIGN: Cross-sectional study. PARTICIPANTS: We used data from the 11 states and one territory that completed the social context module of the 2015 Behavioral Risk Factor Surveillance System (BRFSS). MAIN MEASURES: We estimated the prevalence of housing and food insecurity among patients with cancer, stroke, cardiovascular disease, and chronic lung disease. Logistic regression models were used to assess the independent effects of housing and food insecurity, chronic conditions, and demographics on health care access and health status. KEY RESULTS: Among the chronically ill, 36.71% (95% CI: 35.54-37.88) experienced housing insecurity and 30.60% (95% CI: 29.49-31.71) experienced food insecurity. Cardiovascular and lung disease increased the likelihood of housing (OR 1.69, 95% CI: 1.07-2.66 and OR 1.71, 95% CI: 1.12-2.60, respectively) and food insecurity (OR 1.75, 95% CI: 1.12-2.73 and OR 1.78, 95% CI: 1.20-2.63, respectively). Housing and food insecurity significantly increased the risk of health care access hardship. Being insured or having an income level above 200% of the federal poverty level significantly reduced the likelihood of access hardship, while female gender significantly increased the likelihood. CONCLUSIONS: Chronic illness independently affects housing and food insecurity. In turn, food and housing anxiety leads to reduced access to care, likely due to cost concerns, and correlates with poorer health. A more complete understanding of the pathways by which chronic illness influences social determinants and clinical outcomes is needed.

Optimization of region-of-interest sampling strategies for hepatic MRI proton density fat fraction quantification.

BACKGROUND: Clinical trials utilizing proton density fat fraction (PDFF) as an imaging biomarker for hepatic steatosis have used a laborious region-of-interest (ROI) sampling strategy of placing an ROI in each hepatic segment. PURPOSE: To identify a strategy with the fewest ROIs that consistently achieves close agreement with the nine-ROI strategy. STUDY TYPE: Retrospective secondary analysis of prospectively acquired clinical research data. POPULATION: A total of 391 adults (173 men, 218 women) with known or suspected NAFLD. FIELD STRENGTH/SEQUENCE: Confounder-corrected chemical-shift-encoded 3T MRI using a 2D multiecho gradient-recalled echo technique. ASSESSMENT: An ROI was placed in each hepatic segment. Mean nine-ROI PDFF and segmental PDFF standard deviation were computed. Segmental and lobar PDFF were compared. PDFF was estimated using every combinatorial subset of ROIs and compared to the nine-ROI average. STATISTICAL TESTING: Mean nine-ROI PDFF and segmental PDFF standard deviation were summarized descriptively. Segmental PDFF was compared using a one-way analysis of variance, and lobar PDFF was compared using a paired t-test and a Bland-Altman analysis. The PDFF estimated by every subset of ROIs was informally compared to the nine-ROI average using median intraclass correlation coefficients (ICCs) and Bland-Altman analyses. RESULTS: The study population's mean whole-liver PDFF was 10.1 ± 8.9% (range: 1.1-44.1%). Although there was no significant difference in average segmental (P = 0.452) or lobar (P = 0.154) PDFF, left and right lobe PDFF differed by at least 1.5 percentage points in 25.1% (98/391) of patients. Any strategy with ≥4 ROIs had ICC >0.995. 115 of 126 four-ROI strategies (91%) had limits of agreement (LOA) <1.5%, including four-ROI strategies with two ROIs from each lobe, which all had LOA <1.5%. 14/36 (39%) of two-ROI strategies and 74/84 (88%) of three-ROI strategies had ICC >0.995, and 2/36 (6%) of two-ROI strategies and 46/84 (55%) of three-ROI strategies had LOA <1.5%. DATA CONCLUSION: Four-ROI sampling strategies with two ROIs in the left and right lobes achieve close agreement with nine-ROI PDFF. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:988-994.

MRI proton density fat fraction is robust across the biologically plausible range of triglyceride spectra in adults with nonalcoholic steatohepatitis.

BACKGROUND: Proton density fat fraction (PDFF) estimation requires spectral modeling of the hepatic triglyceride (TG) signal. Deviations in the TG spectrum may occur, leading to bias in PDFF quantification. PURPOSE: To investigate the effects of varying six-peak TG spectral models on PDFF estimation bias. STUDY TYPE: Retrospective secondary analysis of prospectively acquired clinical research data. POPULATION: Forty-four adults with biopsy-confirmed nonalcoholic steatohepatitis. FIELD STRENGTH/SEQUENCE: Confounder-corrected chemical-shift-encoded 3T MRI (using a 2D multiecho gradient-recalled echo technique with magnitude reconstruction) and MR spectroscopy. ASSESSMENT: In each patient, 61 pairs of colocalized MRI-PDFF and MRS-PDFF values were estimated: one pair used the standard six-peak spectral model, the other 60 were six-peak variants calculated by adjusting spectral model parameters over their biologically plausible ranges. MRI-PDFF values calculated using each variant model and the standard model were compared, and the agreement between MRI-PDFF and MRS-PDFF was assessed. STATISTICAL TESTS: MRS-PDFF and MRI-PDFF were summarized descriptively. Bland-Altman (BA) analyses were performed between PDFF values calculated using each variant model and the standard model. Linear regressions were performed between BA biases and mean PDFF values for each variant model, and between MRI-PDFF and MRS-PDFF. RESULTS: Using the standard model, mean MRS-PDFF of the study population was 17.9 ± 8.0% (range: 4.1-34.3%). The difference between the highest and lowest mean variant MRI-PDFF values was 1.5%. Relative to the standard model, the model with the greatest absolute BA bias overestimated PDFF by 1.2%. Bias increased with increasing PDFF (P < 0.0001 for 59 of the 60 variant models). MRI-PDFF and MRS-PDFF agreed closely for all variant models (R2 = 0.980, P < 0.0001). DATA CONCLUSION: Over a wide range of hepatic fat content, PDFF estimation is robust across the biologically plausible range of TG spectra. Although absolute estimation bias increased with higher PDFF, its magnitude was small and unlikely to be clinically meaningful. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:995-1002.

CT for Assessment of Thrombosis and Pulmonary Embolism in Multiple Stages of Single-Ventricle Palliation: Challenges and Suggested Protocols.

The total cavopulmonary connection (TCPC), or Fontan procedure, diverts systemic venous blood directly into the pulmonary arteries and is the palliative surgery of choice for patients with a wide variety of congenital heart diseases with single-ventricle physiologic characteristics. Pulmonary embolism and thrombosis are known complications and are among the major causes of morbidity and mortality in patients after TCPC. Magnetic resonance (MR) imaging is usually performed for postoperative evaluation of patients after single-ventricle repair; however, screening for thrombosis or embolism with MR imaging is not always feasible because of the emergent nature of the clinical presentation or because of artifacts from metallic devices or coils. Computed tomographic (CT) angiography is an effective method for diagnosing pulmonary embolism in children. However, because of altered hemodynamics after single-ventricle palliation, there are unique challenges in achieving optimal opacification of the pulmonary arteries and Fontan circuit that can result in nondiagnostic CT angiographic studies or erroneous image interpretation. Radiologists should be familiar with the multiple stages of single-ventricle palliation, understand the technique for performing pulmonary CT angiography at each stage, and recognize common pitfalls in obtaining and interpreting pulmonary CT angiographic images in patients who have undergone single-ventricle repair. Online supplemental material is available for this article. (©)RSNA, 2016.

Breast Screening Utilization and Cost Sharing Among Employed Insured Women Following the Affordable Care Act: Impact of Race and Income.

Introduction: We assessed changes in screening mammography cost sharing and utilization before and after the Affordable Care Act (ACA) and the revised U.S. Preventive Services Task Force (USPSTF) recommendations by race and income. Methods: We used Optum™© Clinformatics™® Data Mart deidentified patient-level analytic files between 2004 and 2014. We first visually inspected trends for screening mammography utilization and cost-sharing elimination over time by race and income. We then specifically calculated the slopes and compared trends before and after 2009 and 2010 to assess the impact of ACA implementation and USPSTF recommendation revisions on screening mammography cost-sharing elimination and utilization. All analyses were conducted in 2018. Results: A total of 1,763,959 commercially insured women, ages 40-74, were included. Comparing trends for cost-sharing elimination before and after the 2010 ACA implementation, a statistically significant but small upward trend was found among all races and income levels with no racial or income disparities evident. However, screening utilization plateaued or showed a significant decline after the 2009 USPSTF recommendation revision in all income and racial groups except for African Americans in whom screening rates continued to increase after 2009. Conclusions: Impact of ACA cost-sharing elimination did not differ among various racial and income groups. Among our population of employer-based insured women, the racial gap in screening mammography use appeared to have closed and potentially reversed among African American women. Continued monitoring of screening utilization as health care policies and recommendations evolve is required, as these changes may affect race- and income-based disparities.

Measurement of spleen fat on MRI-proton density fat fraction arises from reconstruction of noise.

PURPOSE: This study compares splenic proton density fat fraction (PDFF) measured using confounder-corrected chemical shift-encoded (CSE)-MRI to magnetic resonance spectroscopy (MRS) in human patients at 3T. METHODS: This was a prospectively designed ancillary study to various previously described single-center studies performed in adults and children with known or suspected nonalcoholic fatty liver disease. Patients underwent magnitude-based MRI (MRI-M), complex-based MRI (MRI-C), high signal-to-noise variants (Hi-SNR MRI-M and Hi-SNR MRI-C), and MRS at 3T for spleen PDFF estimation. PDFF from CSE-MRI methods were compared to MRS-PDFF using Wilcoxon signed-rank tests. Demographics were summarized descriptively. Spearman's rank correlations were computed pairwise between CSE-MRI methods. Individual patient measurements were plotted for qualitative assessment. A significance level of 0.05 was used. RESULTS: Forty-seven patients (20 female, 27 male) including 12 adults (median 55 years old) and 35 children (median 12 years old). Median PDFF estimated by MRS, MRI-M, Hi-SNR MRI-M, MRI-C, and Hi-SNR MRI-C was 1.0, 2.3, 1.9, 2.2, and 2.0%. The four CSE-MRI methods estimated statistically significant higher spleen PDFF values compared to MRS (p < 0.0001 for all). Pairwise associations in spleen PDFF values measured by different CSE-MRI methods were weak, with the highest Spearman's rank correlations being 0.295 between MRI-M and Hi-SNR MRI-M; none were significant after correction for multiple comparisons. No qualitative relationship was observed between PDFF measurements among the various methods. CONCLUSION: Overestimation of PDFF by CSE-MRI compared to MRS and poor agreement between related CSE-MRI methods suggest that non-zero PDFF values in human spleen are artifactual.

Technical report: gadoxetate-disodium-enhanced 2D R2* mapping: a novel approach for assessing bile ducts in living donors.

PURPOSE: Gadoxetate-disodium (Gd-EOB-DTPA)-enhanced 3D T1- weighted (T1w) MR cholangiography (MRC) is an efficient method to evaluate biliary anatomy due to T1 shortening of excreted contrast in the bile. A method that exploits both T1 shortening and T2* effects may produce even greater bile duct conspicuity. The aim of our study is to determine feasibility and compare the diagnostic performance of two-dimensional (2D) T1w multi-echo (ME) spoiled gradient-recalled-echo (SPGR) derived R2* maps against T1w MRC for bile duct visualization in living liver donor candidates. MATERIALS AND METHODS: Ten potential living liver donor candidates underwent pretransplant 3T MRI and were included in our study. Following injection of Gd-EOBDTPA and a 20-min delay, 3D T1w MRC and 2D T1w ME SPGR images were acquired. 2D R2* maps were generated inline by the scanner assuming exponential decay. The 3D T1w MRC and 2D R2* maps were retrospectively and independently reviewed in two separate sessions by three radiologists. Visualization of eight bile duct segments was scored using a 4-point ordinal scale. The scores were compared using mixed effects regression model. RESULTS: Imaging was tolerated by all donors and R2* maps were successfully generated in all cases. Visualization scores of 2D R2* maps were significantly higher than 3D T1w MRC for right anterior (p = 0.003) and posterior (p = 0.0001), segment 2 (p < 0.0001), segment 3 (p = 0.0001), and segment 4 (p < 0.0001) ducts. CONCLUSIONS: Gd-EOB-DTPA-enhanced 2D R2* mapping is a feasible method for evaluating the bile ducts in living donors and may be a valuable addition to the living liver donor MR protocol for delineating intrahepatic biliary anatomy.

Fat Quantification in the Abdomen.

Fatty liver disease is characterized histologically by hepatic steatosis, the abnormal accumulation of lipid in hepatocytes. It is classified into alcoholic fatty liver disease and nonalcoholic fatty liver disease, and is an increasingly important cause of chronic liver disease and cirrhosis. Assessing the severity of hepatic steatosis in these conditions is important for diagnostic and prognostic purposes, as hepatic steatosis is potentially reversible if diagnosed early. The criterion standard for assessing hepatic steatosis is liver biopsy, which is limited by sampling error, its invasive nature, and associated morbidity. As such, noninvasive imaging-based methods of assessing hepatic steatosis are needed. Ultrasound and computed tomography are able to suggest the presence of hepatic steatosis based on imaging features, but are unable to accurately quantify hepatic fat content. Since Dixon's seminal work in 1984, magnetic resonance imaging has been used to compute the signal fat fraction from chemical shift-encoded imaging, commonly implemented as out-of-phase and in-phase imaging. However, signal fat fraction is confounded by several factors that limit its accuracy and reproducibility. Recently, advanced chemical shift-encoded magnetic resonance imaging methods have been developed that address these confounders and are able to measure the proton density fat fraction, a standardized, accurate, and reproducible biomarker of fat content. The use of these methods in the liver, as well as in other abdominal organs such as the pancreas, adrenal glands, and adipose tissue will be discussed in this review.

The Link Between Everyday Discrimination, Healthcare Utilization, and Health Status Among a National Sample of Women.

BACKGROUND: Research has not adequately examined the potential negative effects of perceiving routine discrimination on general healthcare utilization or health status, especially among reproductive-aged women. We sought to evaluate the association between everyday discrimination, health service use, and perceived health among a national sample of women in the United States. MATERIALS AND METHODS: Data were drawn from the Women's Healthcare Experiences and Preferences survey, a randomly selected, national probability sample of 1078 U.S. women aged 18-55 years. We examined associations between everyday discrimination (via a standardized scale) on frequency of health service utilization and perceived general health status using chi-square and multivariable logistic regression modeling. RESULTS: Compared with women who reported healthcare visits every 3 years or less (reference group), each one-point increase in discrimination score was associated with higher odds of having healthcare visits annually or more often (odds ratio [OR] = 1.36, confidence interval [95% CI] = 1.01-1.83). Additionally, each one-point increase in discrimination score was significantly associated with lower odds of having excellent/very good perceived health (OR = 0.65; 95% CI = 0.54-0.80). CONCLUSION: Perceived discrimination was associated with increased exposure to the healthcare setting among this national sample of women. Perceived discrimination was also inversely associated with excellent/very good perceived health status.

Novel data sources for women's health research: mapping breast screening online information seeking through Google trends.

RATIONALE AND OBJECTIVES: Millions of people use online search engines everyday to find health-related information and voluntarily share their personal health status and behaviors in various Web sites. Thus, data from tracking of online information seeker's behavior offer potential opportunities for use in public health surveillance and research. Google Trends is a feature of Google which allows Internet users to graph the frequency of searches for a single term or phrase over time or by geographic region. We used Google Trends to describe patterns of information-seeking behavior in the subject of dense breasts and to examine their correlation with the passage or introduction of dense breast notification legislation. MATERIALS AND METHODS: To capture the temporal variations of information seeking about dense breasts, the Web search query "dense breast" was entered in the Google Trends tool. We then mapped the dates of legislative actions regarding dense breasts that received widespread coverage in the lay media to information-seeking trends about dense breasts over time. RESULTS: Newsworthy events and legislative actions appear to correlate well with peaks in search volume of "dense breast". Geographic regions with the highest search volumes have passed, denied, or are currently considering the dense breast legislation. CONCLUSIONS: Our study demonstrated that any legislative action and respective news coverage correlate with increase in information seeking for "dense breast" on Google, suggesting that Google Trends has the potential to serve as a data source for policy-relevant research.