Characterization of Small (< 4 cm) Focal Renal Lesions: Diagnostic Accuracy of Spectral Analysis Using Single-Phase Contrast-Enhanced Dual-Energy CT.

OBJECTIVE: The purpose of this study is to determine whether single-phase contrast-enhanced dual-energy quantitative spectral analysis improves the accuracy of diagnosis of small (< 4.0 cm) renal lesions, compared with conventional single-energy attenuation measurements. MATERIALS AND METHODS: In this retrospective study, 136 consecutive patients (95 men and 41 women; mean age, 54 years) with 144 renal lesions (111 benign and 33 malignant) underwent single-energy unenhanced and dual-energy contrast-enhanced CT of the abdomen. For each renal lesion, attenuation measurements were obtained, and an attenuation change of 15 HU or greater was considered evidence of enhancement. Dual-energy spectral attenuation curves were generated for each lesion. The slope of each curve was measured between 40 and 50 keV (λHU40-50), 40 and 70 keV (λHU40-70), and 40 and 140 keV (λHU40-140). Mean lesion attenuation values and spectral attenuation curve parameters were compared between benign and malignant renal lesions by use of the two-sample t test. Diagnostic accuracy was assessed and validated using cross-validation analysis. RESULTS: With the use of cross-validated optimal thresholds at 100% sensitivity, specificity for differentiating between benign and malignant renal lesions improved significantly when both λHU40-70 and λHU40-140 were used, compared with conventional enhancement measurements (93% [103/111; 95% CI, 86-97%] vs 81% [90/111; 95% CI, 73-88%]) (p = 0.02). The sensitivity of λHU40-70 and λHU40-140 was also higher than that of conventional enhancement measurements, although it was not statistically significant. CONCLUSION: Single-phase contrast-enhanced dual-energy quantitative spectral analysis significantly improves the specificity for characterization of small (< 4.0 cm) renal lesions, compared with conventional single-energy attenuation measurements.

Structured reporting of CT enterography for inflammatory bowel disease: effect on key feature reporting, accuracy across training levels, and subjective assessment of disease by referring physicians.

PURPOSE: To compare the content and accuracy of structured reporting (SR) versus non-structured reporting (NSR) for computed tomographic enterography (CTE) of inflammatory bowel disease (IBD). MATERIALS AND METHODS: This IRB-approved, HIPAA-compliant, retrospective study included 30 adult subjects (15 male, 15 female; mean age 41.9 years) with IBD imaged with CTE. Nine radiologists (3 faculty, 3 abdominal imaging fellows, and 3 senior radiology residents) independently interpreted all examinations using both NSR and SR, separated by four weeks. Reports were assessed for documentation of 15 key reporting features and a subset of 5 features was assessed for accuracy. Thirty faculty reports (15 NSR [5 per reader] and 15 SR [5 per reader]) were randomly selected for review by three referring physicians, who independently rated quality metrics for each report. RESULTS: NSR documented the presence or absence of 8.2 ± 2.2 key features, while SR documented 14.6 ± 0.5 features (p < 0.001). SR resulted in increased documentation of 13 of 15 features including stricture (p < 0.001), fistula (p < 0.001), fluid collection (p = 0.003), and perianal disease (p < 0.001). Among a subset of five features, accuracy for diagnosing multifocal disease was minimally increased when using SR (76% NSR vs. 83% SR; p = 0.01), but accuracy for other features was not affected by report type. Referring physicians significantly preferred SR based on ease of information extraction (p < 0.01). CONCLUSION: Structured reporting of CTE for IBD improved documentation of key reporting features for trainees and faculty, though there was minimal impact on accuracy. Referring physicians subjectively preferred the structured reports.

Dual-Source Single-Energy Multidetector CT Used to Obtain Multiple Radiation Exposure Levels within the Same Patient: Phantom Development and Clinical Validation.

Purpose To develop, in a phantom environment, a method to obtain multidetector computed tomographic (CT) data sets at multiple radiation exposure levels within the same patient and to validate its use for potential dose reduction by using different image reconstruction algorithms for the detection of liver metastases. Materials and Methods The American College of Radiology CT accreditation phantom was scanned by using a dual-source multidetector CT platform. By adjusting the radiation output of each tube, data sets at six radiation exposure levels (100%, 75%, 50%, 37.5%, 25%, and 12.5%) were reconstructed from two consecutive dual-source single-energy (DSSE) acquisitions, as well as a conventional single-source acquisition. A prospective, HIPAA-compliant, institutional review board-approved study was performed by using the same DSSE strategy in 19 patients who underwent multidetector CT of the liver for metastatic colorectal cancer. All images were reconstructed by using conventional weighted filtered back projection (FBP) and sinogram-affirmed iterative reconstruction with strength level of 3 (SAFIRE-3). Objective image quality metrics were compared in the phantom experiment by using multiple linear regression analysis. Generalized linear mixed-effects models were used to analyze image quality metrics and diagnostic performance for lesion detection by readers. Results The phantom experiment showed comparable image quality between DSSE and conventional single-source acquisition. In the patient study, the mean size-specific dose estimates for the six radiation exposure levels were 13.0, 9.8, 5.8, 4.4, 3.2, and 1.4 mGy. For each radiation exposure level, readers' perception of image quality and lesion conspicuity was consistently ranked superior with SAFIRE-3 when compared with FBP (P ≤ .05 for all comparisons). Reduction of up to 62.5% in radiation exposure by using SAFIRE-3 yielded similar reader rankings of image quality and lesion conspicuity when compared with routine-dose FBP. Conclusion A method was developed and validated to synthesize multidetector CT data sets at multiple radiation exposure levels within the same patient. This technique may provide a foundation for future clinical trials aimed at estimating potential radiation dose reduction by using iterative reconstructions. © RSNA, 2016 Online supplemental material is available for this article.

Measuring Problematic Mobile Phone Use: Development and Preliminary Psychometric Properties of the PUMP Scale.

This study aimed to develop and assess the psychometric properties of an English language measure of problematic mobile phone use. Participants were recruited from a university campus, health science center, and other public locations. The sample included 244 individuals (68.4% female) aged 18-75. Results supported a unidimensional factor structure for the 20-item self-report Problematic Use of Mobile Phones (PUMP) Scale. Internal consistency was excellent (α = 0.94). Strong correlations (r = .76, P < .001) were found between the PUMP Scale and an existing scale of cellular phone dependency that was validated in Asia, as well as items assessing frequency and intensity of mobile phone use. Results provide preliminary support for the use of the PUMP Scale to measure problematic use of mobile phones.

SF-6D utility index as measure of minimally important difference in health status change.

OBJECTIVES: To combine anchor- and distribution-based approaches to identify minimally important differences (MIDs) for the short-form six-dimension utility index (SF-6D) and to identify variables associated with self-reported health status change. DESIGN: Descriptive, exploratory, nonexperimental study. SETTING: United States between April 1, 1999, and October 31, 1999. PATIENTS: 2,317 participants of SADD-Sx (Study of Antihypertensive Drugs and Depressive Symptoms), aged 50 years or older and with hypertension and coronary artery disease. INTERVENTION: Patients were randomized into a verapamil SR- or atenolol-led hypertensive treatment strategy and mailed baseline and 1-year surveys. MAIN OUTCOME MEASURE: SF-6D utility scores for patients completing both surveys. RESULTS: The pooled mean (±SD) MID change on the SF-6D of patients whose health status minimally changed was 0.035 ± 0.095. The anchor-based change scores had a median value of 0.036 (interquartile range -0.03 to 0.10). One-third and one-half of the SD of SF-6D change scores were 0.035 and 0.053, respectively. Whites were less likely to report minimally improved health status compared with nonwhites (odds ratio 0.59 [95% CI 0.40-0.88]). Change in SF-6D scores improved prediction of health status change. CONCLUSION: We recommend using the MID range based on all patients combined (-0.03 to 0.10) to interpret SF-6D scores. These estimates can be used in conjunction with other measures of efficacy to determine meaningful changes. SF-6D demonstrates potential utility in predicting minimally important improvement or worsening among patients receiving different pharmacologic medications.

Assessing locomotor-stimulating effects of cocaine in rodents.

Locomotor activity procedures are useful for characterizing the behavioral effects of a drug, the influence of pharmacological, neurobiological, and environmental manipulations on drug sensitivity, and changes in activity following repeated administration (e.g., tolerance or sensitization) are thought to be related to the development of an addiction-like behavioral phenotype. The effects of cocaine on locomotor activity have been relatively extensively characterized. Many of the published studies use between-subject experimental designs, even though changes in sensitivity within a particular individual due to experimental manipulations, or behavioral and pharmacological histories is potentially the most important outcome as these changes may relate to differential development of an addiction-like phenotype in some, but not all, animals (including humans). The two behavioral protocols described herein allow extensive within-subject analyses. The first protocol uses daily locomotor activity levels as a stable baseline to assess the effects of experimental manipulations, and the second uses a pre- versus post-session experimental design to demonstrate the importance of drug-environment interactions in determining the behavioral effects of cocaine.