Occult Regions of Suppressed Coherence in Liver B-Mode Images.

Ultrasound is an essential tool for diagnosing and monitoring diseases, but it can be limited by poor image quality. Lag-one coherence (LOC) is an image quality metric that can be related to signal-to-noise ratio and contrast-to-noise ratio. In this study, we examine matched LOC and B-mode images of the liver to discern patterns of low image quality, as indicated by lower LOC values, occurring beneath the abdominal wall, near out-of-plane vessels and adjacent to hyperechoic targets such the liver capsule.

HSP90-Specific nIR Probe Identifies Aggressive Prostate Cancers: Translation from Preclinical Models to a Human Phase I Study.

A noninvasive test to discriminate indolent prostate cancers from lethal ones would focus treatment where necessary while reducing overtreatment. We exploited the known activity of heat shock protein 90 (Hsp90) as a chaperone critical for the function of numerous oncogenic drivers, including the androgen receptor and its variants, to detect aggressive prostate cancer. We linked a near-infrared fluorescing molecule to an HSP90 binding drug and demonstrated that this probe (designated HS196) was highly sensitive and specific for detecting implanted prostate cancer cell lines with greater uptake by more aggressive subtypes.

Dual-Energy CT Vital Iodine Tumor Burden for Response Assessment in Patients With Metastatic GIST Undergoing TKI Therapy: Comparison With Standard CT and FDG PET/CT Criteria.

CT-based criteria for assessing the gastrointestinal stromal tumor (GIST) response to tyrosine kinase inhibitor (TKI) therapy are limited in part because tumor attenuation is influenced by treatment-related changes including hemorrhage and calcification. The iodine concentration may be less impacted by such changes. The purpose of this study was to determine whether the dual-energy CT (DECT) vital iodine tumor burden (TB) allows improved differentiation between treatment responders and nonresponders among patients with metastatic GIST who are undergoing TKI therapy compared with established CT and PET/CT criteria.

Comparison of clinical efficacy, subjective user experience, and safety for two different core biopsy needles, the Achieve® and Marquee®.

Purpose: To compare clinical efficacy, subjective radiologist preference, and complication rates for two different core biopsy needles, the Achieve® and Marquee®.

Methods: Retrospective review included consecutive patients who underwent 18 gauge non-targeted core liver biopsy, 30 with Achieve® (Merit Medical) and 30 with Marquee® (BD Bard) Pathologist (blinded to needle type) reviewed specimen total length, maximum width, and portal triad count. Sixteen radiologists subjectively rated (1 to 5(best)) each needle for cocking, firing, recoil, chamber exposure, handling, and overall.

Can procedure time for paracentesis be optimized based on bottle selection?

Purpose: The purpose of our study was to assess if plastic containers could decrease the overall procedure time for paracentesis relative to more commonly used glass containers.

Methods: In this IRB exempt study, initial pilot data comparing filling time of glass and plastic containers in an ex vivo setting under identical conditions revealed power calculations that n = 37 patients per group would be needed to achieve standard deviation (SD) = 60 s, difference (diff) = 40 s, two-tailed alpha-level 0.05, and power 80%.

Hemodialysis catheter integrity during mechanical power injection of iodinated contrast medium for computed tomography angiography.

Purpose: CT angiography (CTA) requires vascular access with flow rates of 5-7 mL/s. Hemodialysis (HD) is performed at 6-10 mL/s. The purpose of our study is to evaluate the structural integrity of HD catheters in the administration of contrast media via a mechanical power injector under varying conditions.

Variability of quantitative measurements of metastatic liver lesions: a multi-radiation-dose-level and multi-reader comparison.

Purpose: To evaluate the variability of quantitative measurements of metastatic liver lesions by using a multi-radiation-dose-level and multi-reader comparison.

Methods: Twenty-three study subjects (mean age, 60 years) with 39 liver lesions who underwent a single-energy dual-source contrast-enhanced staging CT between June 2015 and December 2015 were included. CT data were reconstructed with seven different radiation dose levels (ranging from 25 to 100%) on the basis of a single CT acquisition.

Ultrasound-guided non-targeted liver core biopsy: comparison of the efficacy of two different core needle biopsy systems using an ex-vivo animal model and retrospective review of clinical experience.

Purpose: To compare the efficacy of two 18-gauge core needle biopsy systems, the Achieve® (Merit Medical) and the Marquee® (BD Bard), using an ex-vivo animal liver model and retrospective review of clinical experience.

Methods: Sixty ex-vivo liver biopsy samples were obtained using the Achieve® (n = 30) and the Marquee® (n = 30) needles. In addition, 20 liver biopsy samples from 20 patients obtained using the Achieve® (n = 10) and Marquee® (n = 10) were compared retrospectively.

Evaluation of Intraindividual Contrast Enhancement Variability for Determining the Maximum Achievable Consistency in CT.

The purpose of this study was to quantify temporal variability in vascular and parenchymal enhancement within the same patient and to determine technique-related factors contributing to this variability. We identified 100 patients who underwent four CT scans within 12 months with identical acquisition and contrast injection parameters. Enhancement was recorded in the abdominal aorta, main portal vein, liver parenchyma, and subcutaneous fat.

Reproducibility of CT Radiomic Features within the Same Patient: Influence of Radiation Dose and CT Reconstruction Settings.

Background Results of recent phantom studies show that variation in CT acquisition parameters and reconstruction techniques may make radiomic features largely nonreproduceable and of limited use for prognostic clinical studies. Purpose To investigate the effect of CT radiation dose and reconstruction settings on the reproducibility of radiomic features, as well as to identify correction factors for mitigating these sources of variability. Materials and Methods This was a secondary analysis of a prospective study of metastatic liver lesions in patients who underwent staging with single-energy dual-source contrast material-enhanced staging CT between September 2011 and April 2012.

Comparison of Iodine Quantification and Conventional Attenuation Measurements for Differentiating Small, Truly Enhancing Renal Masses From High-Attenuation Nonenhancing Renal Lesions With Dual-Energy CT.

The purpose of this study is to determine whether iodine quantification techniques from contrast-enhanced dual-energy CT (DECT) data allow equal differentiation of small enhancing renal masses from high-attenuation (> 20 HU of unenhanced attenuation) nonenhancing lesions, compared with conventional attenuation measurements. A total of 220 nonconsecutive patients (mean [± SD] age, 66 ± 13 years; 130 men and 90 women) with 265 high-attenuation renal lesions (mean attenuation, 54 ± 33 HU; 91 enhancing lesions) were included. Each patient underwent single-energy unenhanced CT followed by DECT during the nephrographic phase using one of four different high-end DECT platforms (first- and second-generation rapid-kilovoltage-switching DECT platforms and second- and third-generation dual-source DECT platforms).

Virtual Unenhanced Images at Dual-Energy CT: Influence on Renal Lesion Characterization.

Background Dual-energy (DE) CT allows reconstruction of virtual noncontrast (VNC) images from a single-phase contrast agent-enhanced examination, potentially reducing the need for multiphasic CT to characterize renal lesions. However, data regarding diagnostic performance of VNC images for the characterization of renal lesions are limited. Purpose To determine whether renal mass CT performed by using VNC images allows for reliable identification of renal lesions and differentiation of contrast-enhanced from unenhanced lesions, compared with unenhanced images.

Negative Biopsy of Focal Hepatic Lesions: Decision Tree Model for Patient Management.

Objective: The purpose of this study was to investigate patient- and procedure-related variables affecting the false-negative rate of ultrasound (US)-guided liver biopsy and to develop a standardized patient-tailored predictive model for the management of negative biopsy results.

Materials And Methods: We retrospectively included 389 patients (mean age ± SD, 62 ± 12 years old) who had undergone US-guided liver biopsy of 405 liver lesions between January 1, 2013, and June 30, 2015. We collected multiple patient- and procedure-related variables.

Dual-Energy CT Material Density Iodine Quantification for Distinguishing Vascular From Nonvascular Renal Lesions: Normalization Reduces Intermanufacturer Threshold Variability.

Objective: The purpose of this study was to determine whether a single, uniform normalized iodine threshold reduces variability and enables reliable differentiation between vascular and nonvascular renal lesions independent of the dual-energy CT (DECT) platform used.

Materials And Methods: In this retrospective, HIPAA-compliant, institutional review board-approved study, 247 patients (156 men, 91 women; mean age ± SD, 67 ± 12 years old) with 263 renal lesions (193 nonvascular, 70 vascular) underwent unenhanced single-energy and contrast-enhanced DECT scans. One hundred and six nonvascular and 38 vascular lesions were scanned on two dual-source DECT (dsDECT) scanners, and 87 nonvascular and 32 vascular lesions were scanned on two rapid-kilovoltage-switching single-source DECT (rsDECT) scanners.

High-Pitch Wide-Coverage Fast-Kilovoltage-Switching Dual-Energy CT: Impact of Pitch on Noise, Spatial Resolution, and Iodine Quantification in a Phantom Study.

Objective: The purpose of this study was to assess the impact of high pitch values on image noise, spatial resolution, and iodine quantification in single-source wide-coverage fast-kilovoltage-switching dual-energy CT (DECT).

Materials And Methods: Two phantom experiments were conducted. First, image noise and spatial resolution in the x-, y-, and z-directions were assessed.

Can Texture Analysis Be Used to Distinguish Benign From Malignant Adrenal Nodules on Unenhanced CT, Contrast-Enhanced CT, or In-Phase and Opposed-Phase MRI?

Objective: The purpose of this study is to determine whether second-order texture analysis can be used to distinguish lipid-poor adenomas from malignant adrenal nodules on unenhanced CT, contrast-enhanced CT (CECT), and chemical-shift MRI.

Materials And Methods: In this retrospective study, 23 adrenal nodules (15 lipid-poor adenomas and eight adrenal malignancies) in 20 patients (nine female patients and 11 male patients; mean age, 59 years [range, 15-80 years]) were assessed. All patients underwent unenhanced CT, CECT, and chemical-shift MRI.

EFFECTIVE DOSE ESTIMATION FROM ORGAN DOSE MEASUREMENTS IN FAST-kV SWITCH DUAL ENERGY COMPUTED TOMOGRAPHY.

The purpose of this study was to validate a novel approach to estimating effective dose (E) in 'fast-kV switch dual energy computed tomography' using MOSFET detectors. The effective energy of the combined dual energy environment was characterized with the dual energy CT scanner and then MOSFETs were calibrated matching to the effective energy of the dual energy CT beam with a conventional CT beam. The calibration method was then experimentally validated by comparing the dose between MOSFET and an ion chamber (IC) using a standard CTDI body phantom.

How accurate and precise are CT based measurements of iodine concentration? A comparison of the minimum detectable concentration difference among single source and dual source dual energy CT in a phantom study.

Objectives: To assess the impact of scan- and patient-related factors on the error and the minimum detectable difference in iodine concentration among different generations of single-source (SS) fast kV-switching and dual-source (DS) dual-energy CT (DECT).

Methods: Lesions having eight different iodine concentrations (0.2-4 mgI/mL) were emulated in a 3D-printed phantom of medium and large size.

Can Realistic Liver Tissue Surrogates Accurately Quantify the Impact of Reduced-kV Imaging on Attenuation and Contrast of Parenchyma and Lesions?

Rationale And Objectives: To assess if a liquid tissue surrogate for the liver (LTSL) can emulate contrast-enhanced liver parenchyma and lesions and quantify the impact of reduced-kV imaging as a function of lesion contrast, phase of enhancement, and phantom size.

Materials And Methods: First, CT attenuation of LTSL- and water-iodine solutions were measured as a function of iodine concentration and tube potential. For each solution, the iodine concentration was determined to emulate liver parenchyma at 120 kV.

Characterization of Small Incidental Indeterminate Hypoattenuating Hepatic Lesions: Added Value of Single-Phase Contrast-Enhanced Dual-Energy CT Material Attenuation Analysis.

Objective: The objective of this study is to determine whether single-phase contrast-enhanced dual-energy CT (DECT) material attenuation analysis improves the characterization of small (< 2.0 cm) incidental indeterminate hypoattenuating hepatic lesions, compared with conventional single-energy CT evaluation.

Materials And Methods: This retrospective study involved 55 patients (24 men and 31 women; mean [± SD] age, 63.

A Third-Generation Adaptive Statistical Iterative Reconstruction Technique: Phantom Study of Image Noise, Spatial Resolution, Lesion Detectability, and Dose Reduction Potential.

Objective: The purpose of this study was to assess image noise, spatial resolution, lesion detectability, and the dose reduction potential of a proprietary third-generation adaptive statistical iterative reconstruction (ASIR-V) technique.

Materials And Methods: A phantom representing five different body sizes (12-37 cm) and a contrast-detail phantom containing lesions of five low-contrast levels (5-20 HU) and three sizes (2-6 mm) were deployed. Both phantoms were scanned on a 256-MDCT scanner at six different radiation doses (1.

Hepatic Heterogeneity and Attenuation on Contrast-Enhanced CT in Patients With the Hypovolemic Shock Complex: Objective Classification Using a Contemporary Cohort.

Objective: When objectively measured on computed tomography (CT), does hepatic heterogeneity or overall liver attenuation predict the presence of shock?

Methods: This retrospective study included 73 patients (mean age 33 years) with the hypoperfusion shock complex (HSC) on CT (cases) and 100 patients (mean age 43 years) with negative trauma CT scans (controls). Liver heterogeneity was calculated by using consistently sized regions of interest (ROIs) to measure the 2 highest and the 2 lowest areas of hepatic density (in Hounsfield units [HU]). The difference between the means of the 2 highest and 2 lowest ROIs was considered the heterogeneity.

Renal Lesion Characterization with Spectral CT: Determining the Optimal Energy for Virtual Monoenergetic Reconstruction.

Purpose To investigate the relationship between energy level of virtual monoenergetic (VM) imaging and sensitivity in the detection of minimally enhancing renal lesions. Materials and Methods Phantoms simulating unenhanced and contrast material-enhanced renal parenchyma were equipped with inserts containing different concentrations of iodine (range, 0-1.15 mg iodine per milliliter).

Splenic contraction: a new member of the hypovolemic shock complex.

Objective: The objective of the article is to assess changes in splenic volume in the setting of hypovolemic shock; splenic enhancement in hypovolemic shock is also assessed.

Materials/methods: 71 consecutive adult patients with the hypovolemic shock complex on computed tomography (CT) were identified. Spleen volume and enhancement were compared to a baseline CT scan (without shock) or to height- and sex-corrected normal values and a control population when a comparison CT was unavailable.

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.