Diagnostic accuracy of dual-layer spectral CT for osteolytic vertebral metastases.

Objectives: To evaluate whether dual-layer spectral computed tomography, compared with conventional CT, improves diagnostic accuracy for osteolytic vertebral metastases. Furthermore, to investigate the influence of dual-layer CT on the subjective visibility of metastases.

Materials And Methods: In this single-center retrospective study, consecutive patients with an untreated primary tumor who underwent dual-layer CT and either MRI or PET-CT as reference standard within 14 days were included.

Computed tomography-based calcium scoring in cadaver leg arteries: Influence of dose, reader, and reconstruction algorithm.

Purpose: Computed tomography (CT) might be a good diagnostic test to accurately quantify calcium in vascular beds but there are multiple factors influencing the quantification. The aim of this study was to investigate the influence of different computed tomography protocol settings in the quantification of calcium in the lower extremities using modified Agatston and volume scores.

Methods: Fresh-frozen human legs were scanned at different tube current protocols and reconstructed at different slice thickness.

Emphysema quantification using chest CT: influence of radiation dose reduction and reconstruction technique.

Background: Computed tomography (CT) emphysema quantification is affected by both radiation dose (i.e. image noise) and reconstruction technique.

Image quality of conventional images of dual-layer SPECTRAL CT: A phantom study.

Purpose: Spectral CT using a dual layer detector offers the possibility of retrospectively introducing spectral information to conventional CT images. In theory, the dual-layer technology should not come with a dose or image quality penalty for conventional images. In this study, we evaluate the influence of a dual-layer detector (IQon Spectral CT, Philips Healthcare) on the image quality of conventional CT images, by comparing these images with those of a conventional but otherwise technically comparable single-layer CT scanner (Brilliance iCT, Philips Healthcare), by means of phantom experiments.

Contrast agent concentration optimization in CTA using low tube voltage and dual-energy CT in multiple vendors: a phantom study.

We investigated the feasibility and extent to which iodine concentration can be reduced in computed tomography angiography imaging of the aorta and coronary arteries using low tube voltage and virtual monochromatic imaging of 3 major dual-energy CT (DECT) vendors. A circulation phantom was imaged with dual source CT (DSCT), gemstone spectral imaging (GSI) and dual-layer spectral detector CT (SDCT). For each scanner, a reference scan was acquired at 120 kVp using routine iodine concentration (300 mg I/ml).

Radiation dose reduction for CT assessment of urolithiasis using iterative reconstruction: A prospective intra-individual study.

Objective: To assess the performance of hybrid (HIR) and model-based iterative reconstruction (MIR) in patients with urolithiasis at reduced-dose computed tomography (CT).

Methods: Twenty patients scheduled for unenhanced abdominal CT for follow-up of urolithiasis were prospectively included. Routine dose acquisition was followed by three low-dose acquisitions at 40%, 60% and 80% reduced doses.

Radiation dose reduction in pediatric great vessel stent computed tomography using iterative reconstruction: A phantom study.

Background: To study dose reduction using iterative reconstruction (IR) for pediatric great vessel stent computed tomography (CT).

Methods: Five different great vessel stents were separately placed in a gel-containing plastic holder within an anthropomorphic chest phantom. The stent lumen was filled with diluted contrast gel.

Accuracy of bone mineral density quantification using dual-layer spectral detector CT: a phantom study.

Objectives: To investigate the accuracy of bone mineral density (BMD) quantification using dual-layer spectral detector CT (SDCT) at various scan protocols.

Methods: Two validated anthropomorphic phantoms containing inserts of 50-200 mg/cm calcium hydroxyapatite (HA) were scanned using a 64-slice SDCT scanner at various acquisition protocols (120 and 140 kVp, and 50, 100 and 200 mAs). Regions of interest (ROIs) were placed in each insert and mean attenuation profiles at monochromatic energy levels (90-200 keV) were constructed.

Feasibility and accuracy of dual-layer spectral detector computed tomography for quantification of gadolinium: a phantom study.

Objectives: The aim of this study was to evaluate the feasibility and accuracy of dual-layer spectral detector CT (SDCT) for the quantification of clinically encountered gadolinium concentrations.

Methods: The cardiac chamber of an anthropomorphic thoracic phantom was equipped with 14 tubular inserts containing different gadolinium concentrations, ranging from 0 to 26.3 mg/mL (0.

Submillisievert coronary calcium quantification using model-based iterative reconstruction: A within-patient analysis.

Purpose: To determine the effect of model-based iterative reconstruction (IR) on coronary calcium quantification using different submillisievert CT acquisition protocols.

Methods: Twenty-eight patients received a clinically indicated non contrast-enhanced cardiac CT. After the routine dose acquisition, low-dose acquisitions were performed with 60%, 40% and 20% of the routine dose mAs.

Aortic Valve and Thoracic Aortic Calcification Measurements: How Low Can We Go in Radiation Dose?

Objective: This study aimed to determine the lowest radiation dose and iterative reconstruction level(s) at which computed tomography (CT)-based quantification of aortic valve calcification (AVC) and thoracic aortic calcification (TAC) is still feasible.

Methods: Twenty-eight patients underwent a cardiac CT and 20 patients a chest CT at 4 different dose levels (routine dose and approximately 40%, 60%, and 80% reduced dose). Data were reconstructed with filtered back projection, 3 iDose levels, and 3 iterative model-based reconstruction levels.

Pulmonary Nodule Volumetry at Different Low Computed Tomography Radiation Dose Levels With Hybrid and Model-Based Iterative Reconstruction: A Within Patient Analysis.

Objective: The aim of the study was to determine the effects of dose reduction and iterative reconstruction (IR) on pulmonary nodule volumetry.

Methods: In this prospective study, 25 patients scheduled for follow-up of pulmonary nodules were included. Computed tomography acquisitions were acquired at 4 dose levels with a median of 2.

Effect of radiation dose reduction and iterative reconstruction on computer-aided detection of pulmonary nodules: Intra-individual comparison.

Objective: To evaluate the effect of radiation dose reduction and iterative reconstruction (IR) on the performance of computer-aided detection (CAD) for pulmonary nodules.

Methods: In this prospective study twenty-five patients were included who were scanned for pulmonary nodule follow-up. Image acquisition was performed at routine dose and three reduced dose levels in a single session by decreasing mAs-values with 45%, 60% and 75%.

Dose reduction with iterative reconstruction for coronary CT angiography: a systematic review and meta-analysis.

Objective: To investigate the achievable radiation dose reduction for coronary CT angiography (CCTA) with iterative reconstruction (IR) in adults and the effects on image quality.

Methods: PubMed and EMBASE were searched, and original articles concerning IR for CCTA in adults using prospective electrocardiogram triggering were included. Primary outcome was the effective dose using filtered back projection (FBP) and IR.

Finding the optimal dose reduction and iterative reconstruction level for coronary calcium scoring.

Objective: To assess the maximally achievable computed tomography (CT) dose reduction for coronary artery calcium (CAC) scoring with iterative reconstruction (IR) by using phantom-experiments and a systematical within-patient study.

Methods: Our local institutional review-board approved this study and informed consent was obtained from all participants. A phantom and patient study were conducted with 30 patients (23 men, median age 55.

Achievable dose reduction using iterative reconstruction for chest computed tomography: A systematic review.

Objectives: Iterative reconstruction (IR) allows for dose reduction with maintained image quality in CT imaging. In this systematic review the reported effective dose reductions for chest CT and the effects on image quality are investigated.

Methods: A systematic search in PubMed and EMBASE was performed.

Hybrid and model-based iterative reconstruction techniques for pediatric CT.

OBJECTIVE. Radiation exposure from CT examinations should be reduced to a minimum in children. Iterative reconstruction (IR) is a method to reduce image noise that can be used to improve CT image quality, thereby allowing radiation dose reduction.

Coronary artery calcification scoring with state-of-the-art CT scanners from different vendors has substantial effect on risk classification.

Purpose: To determine the intervendor variability of Agatston scoring determined with state-of-the-art computed tomographic (CT) systems from the four major vendors in an ex vivo setup and to simulate the subsequent effects on cardiovascular risk reclassification in a large population-based cohort.

Materials And Methods: Research ethics board approval was not necessary because cadaveric hearts from individuals who donated their bodies to science were used. Agatston scores obtained with CT scanners from four different vendors were compared.

Computed tomography radiation dose reduction: effect of different iterative reconstruction algorithms on image quality.

Objective: We evaluated the effects of hybrid and model-based iterative reconstruction (IR) algorithms from different vendors at multiple radiation dose levels on image quality of chest phantom scans.

Methods: A chest phantom was scanned on state-of-the-art computed tomography scanners from 4 vendors at 4 dose levels (4.1 mGy, 3.

The impact of CT radiation dose reduction and iterative reconstruction algorithms from four different vendors on coronary calcium scoring.

Objectives: To analyse the effects of radiation dose reduction and iterative reconstruction (IR) algorithms on coronary calcium scoring (CCS).

Methods: Fifteen ex vivo human hearts were examined in an anthropomorphic chest phantom using computed tomography (CT) systems from four vendors and examined at four dose levels using unenhanced prospectively ECG-triggered protocols. Tube voltage was 120 kV and tube current differed between protocols.

Dose reduction for coronary calcium scoring with hybrid and model-based iterative reconstruction: an ex vivo study.

Purpose: To determine the influence of dose reduction on coronary calcium scoring using hybrid and model-based iterative reconstruction (IR) techniques.

Methods: Fifteen ex vivo hearts were scanned in a phantom representing an average adult person at routine dose and three levels of dose reduction; 27, 55 and 82% reduced-dose, respectively. All images were reconstructed using filtered back-projection (FBP), hybrid IR (iDose4, levels 1, 4 and 7) as well as model-based IR iterative model reconstruction (IMR, levels 1, 2 and 3).

The impact of a new model-based iterative reconstruction algorithm on prosthetic heart valve related artifacts at reduced radiation dose MDCT.

To assess the impact of hybrid iterative reconstruction (IR) and novel model-based iterative reconstruction (IMR) and dose reduction on prosthetic heart valve (PHV) related artifacts and objective image quality. One transcatheter and two mechanical PHVs were embedded in diluted contrast-gel, inserted in an anthropomorphic phantom and imaged stationary with retrospectively ECG-gated computed tomography. Eight acquisitions were obtained of each PHV at 120 kV, 600 mAs (routine), 300 and 150 mAs (reduced dose).

The effect of iterative reconstruction on quantitative computed tomography assessment of coronary plaque composition.

To compare coronary plaque size and composition as well as degree of coronary artery stenosis on coronary Computed Tomography angiography (CCTA) using three levels of iterative reconstruction (IR) with standard filtered back projection (FBP). In 63 consecutive patients with a clinical indication for CCTA 55 coronary plaques were analysed. Raw data were reconstructed using standard FBP and levels 2, 4 and 6 of a commercially available IR algorithm (iDose(4)).

The effects of computed tomography with iterative reconstruction on solid pulmonary nodule volume quantification.

Background: The objectives of this study were to evaluate the influence of iterative reconstruction (IR) on pulmonary nodule volumetry with chest computed tomography (CT).

Methods: Twenty patients (12 women and 8 men, mean age 61.9, range 32-87) underwent evaluation of pulmonary nodules with a 64-slice CT-scanner.

Iterative reconstruction does not substantially delay CT imaging in an emergency setting.

Objectives: To evaluate the effects of iterative reconstruction (IR) on reconstruction time and speed in two commonly encountered acquisition protocols in an emergency setting: pulmonary CT angiography (CTA) and total body trauma CT.

Methods: Twenty-five patients underwent a pulmonary CTA for evaluation of pulmonary embolisms and 15 patients underwent a total body CT after a traumatic event on a 256-slice CT. Images were reconstructed with filtered back-projection (FBP) and two IR levels.