Dual-energy CT based monitoring of treatment-induced bone marrow changes in lung cancer patients: preliminary results.

Background: Systemic lung cancer treatment-induced changes in bone marrow attenuation assessed via dual-energy CT-based virtual non-calcium (VNCa) imaging of the axial skeleton and their relationship to hematological laboratory have not yet been investigated.

Methods: VNCa bone marrow images of the axial skeleton derived from 93 unenhanced reduced dose dual-energy CTs of the thorax and abdomen of 31 patients were retrospectively analyzed. Each patient had received one pre-therapy baseline exam and two consecutive follow-up exams (FU1 and FU2) at a mean of 7.

Quantifying the bone marrow composition of the healthy adult wrist with dual-energy CT.

Purpose: Purpose of this study was to investigate Dual-energy CT (DECT) derived virtual non-calcium (VNCa) values for absolute quantification of the bone marrow composition in the wrist.

Materials And Methods: We prospectively included consecutive adult participants and examined their wrists with DECT. Ranges of VNCa and calcium values were measured in the carpal bones, radius and ulna using a semi-automatic method.

Dual-Energy CT-Based Bone Marrow Imaging in Multiple Myeloma: Assessment of Focal Lesions in Relation to Disease Status and MRI Findings.

Rationale And Objectives: To assess focal multiple myeloma bone lesions via dual-energy CT-based virtual noncalcium (VNCa) bone marrow imaging in relation to the overall hematological disease status and MRI findings.

Materials And Methods: We retrospectively evaluated 103 focal osteolytic lesions of the axial skeleton in VNCa bone marrow images of 32 patients. Region of interest-based attenuation measurements were correlated with T1w signal intensity and apparent diffusion coefficient (ADC).

Low-dose dual-energy CT for stone characterization: a systematic comparison of two generations of split-filter single-source and dual-source dual-energy CT.

Purpose: To compare noise texture and accuracy to differentiate uric acid from non-uric acid urinary stones among four different single-source and dual-source DECT approaches in an ex vivo phantom study.

Methods: Thirty-two urinary stones embedded in gelatin were mounted on a Styrofoam disk and placed into a water-filled phantom. The phantom was imaged using four different DECT approaches: (A) dual-source DECT (DS-DE); (B) 1st generation split-filter single-source DECT (SF1-TB); (C) 2nd generation split-filter single-source DECT (SF2-TB) and (D) 2nd generation split-filter single-source DECT using serial acquisitions (SF2-TS).

Dual-energy CT angiography in suspected pulmonary embolism: influence of injection protocols on image quality and perfused blood volume.

To compare intravenous contrast material (CM) injection protocols for dual-energy CT pulmonary angiography (CTPA) in patients with suspected acute pulmonary embolism with regard to image quality and pulmonary perfused blood volume (PBV) values. A total of 198 studies performed with four CM injection protocols varying in CM volume and iodine delivery rates (IDR) were retrospectively included: (A) 60 ml at 5 ml/s (IDR = 1.75gI/s), (B) 50 ml at 5 ml/s (IDR = 1.

Optimising dual-energy CT scan parameters for virtual non-calcium imaging of the bone marrow: a phantom study.

Background: We investigated the influence of dose, spectral separation, pitch, rotation time, and reconstruction kernel on accuracy and image noise of virtual non-calcium images using a bone marrow phantom.

Methods: The phantom was developed at our institution and scanned using a third-generation dual-source dual-energy CT scanner at five different spectral separations by varying the tube-voltage combinations (70 kV/Sn150 kV, 80 kV/Sn150 kV, 90 kV/Sn150 kV, and 100 kV/Sn150 kV, all with 0.6-mm tin filter [Sn]; 80 kV/140 kV without tin filter) at six different doses (volume computed tomography dose index from 1 to 80 mGy).

Optimized management of urolithiasis by coloured stent-stone contrast using dual-energy computed tomography (DECT).

Background: We analysed in vitro the appearance of commonly used ureteral stents with dual-energy computed tomography (DECT) and we used these characteristics to optimize the differentiation between stents and adjacent stone.

Methods: We analysed in vitro a selection of 36 different stents from 7 manufacturers. They were placed in a self-build phantom model and measured using the SOMATOM® Force Dual Source CT-Scanner (Siemens, Forchheim, Germany).

Optimal Kiloelectron Volt for Noise-Optimized Virtual Monoenergetic Images of Dual-Energy Pediatric Abdominopelvic Computed Tomography: Preliminary Results.

Objective: To compare quantitative and qualitative image quality parameters in pediatric abdominopelvic dual-energy CT (DECT) using noise-optimized virtual monoenergetic image (VMI) and conventional VMI at different kiloelectron volt (keV) levels.

Materials And Methods: Thirty-six consecutive abdominopelvic DECT scans were retrospectively included. Noise-optimized VMI and conventional VMI were reconstructed at seven energy levels, from 40 keV to 100 keV at 10 keV intervals.

Dual-energy CT for liver iron quantification in patients with haematological disorders.

Objectives: To retrospectively quantify liver iron content in haematological patients suspected of transfusional haemosiderosis using dual-energy CT (DECT) and correlate with serum ferritin levels and estimated quantity of transfused iron.

Methods: One hundred forty-seven consecutive dual-source dual-energy non-contrast chest-CTs in 110 haematologic patients intended primarily for exclusion of pulmonary infection between September 2016 and June 2017 were retrospectively evaluated. Image data was post-processed with a software prototype.

Dual-Energy Computed Tomography: Technology and Challenges.

Dual-energy computed tomography (CT) is an imaging technique in which the same axial slice of the patient is scanned with two different X-ray spectra in order to extract chemical information or improve diagnostic image quality. This method is useful for the detection or visualization of heavy atoms like iodine but the differentiation of soft tissue types containing only light atoms is usually not markedly improved compared with single-energy CT. The commercially available dual-energy CT scanners use different technological approaches that differ in complexity and result quality.

Dual-energy CT of the bone marrow in multiple myeloma: diagnostic accuracy for quantitative differentiation of infiltration patterns.

Objectives: Bone marrow imaging patterns in patients with multiple myeloma possess prognostic and potential therapeutic relevance. We aim to evaluate whether different magnetic resonance imaging (MRI) patterns also result in different bone marrow dual-energy computed tomography (DECT) virtual non-calcium (VNCa) attenuation values.

Methods: The institutional review board approved this study.

Validation of proton stopping power ratio estimation based on dual energy CT using fresh tissue samples.

Dual energy CT (DECT) has been shown, in theoretical and phantom studies, to improve the stopping power ratio (SPR) determination used for proton treatment planning compared to the use of single energy CT (SECT). However, it has not been shown that this also extends to organic tissues. The purpose of this study was therefore to investigate the accuracy of SPR estimation for fresh pork and beef tissue samples used as surrogates of human tissues.

Photon-Counting Computed Tomography for Vascular Imaging of the Head and Neck: First In Vivo Human Results.

Purpose: The purpose of this study was to evaluate image quality of a spectral photon-counting detector (PCD) computed tomography (CT) system for evaluation of major arteries of the head and neck compared with conventional single-energy CT scans using energy-integrating detectors (EIDs).

Methods: In this institutional review board-approved study, 16 asymptomatic subjects (7 men) provided informed consent and received both PCD and EID contrast-enhanced CT scans of the head and neck (mean age, 58 years; range, 46-75 years). Tube settings were (EID: 120 kVp/160 mA vs PCD: 140 kVp/108 mA) for all volunteers.

Unenhanced Dual-Energy Computed Tomography: Visualization of Brain Edema.

Purpose: The aim of this study was to determine whether dual-energy computed tomography (DECT) imaging is superior to conventional noncontrast computed tomography (CT) imaging for the detection of acute ischemic stroke.

Materials And Methods: This was a retrospective, single-center study of 40 patients who presented to the emergency department (ED) of a major, acute care, teaching center with signs and symptoms of acute stroke. Only those patients who presented to the ED within 4 hours of symptom onset were included in this study.

A comparison of relative proton stopping power measurements across patient size using dual- and single-energy CT.

Purpose: To evaluate the accuracy and precision across phantom size of a dual-energy computed tomography (DECT) technique used to calculate relative proton stopping power (SPR) in tissue-simulating materials and a silicone implant relative to conventional single-energy CT (SECT).

Material And Methods: A 32 cm lateral diameter (CIRS model 062M, Norfolk, Virginia) electron density phantom containing inserts which simulated the chemical composition of eight tissues in a solid-water background was scanned using SECT and DECT. A liquid water insert was included to confirm CT number accuracy.

Spectral performance of a whole-body research photon counting detector CT: quantitative accuracy in derived image sets.

Photon-counting computed tomography (PCCT) uses a photon counting detector to count individual photons and allocate them to specific energy bins by comparing photon energy to preset thresholds. This enables simultaneous multi-energy CT with a single source and detector. Phantom studies were performed to assess the spectral performance of a research PCCT scanner by assessing the accuracy of derived images sets.

Advanced virtual monochromatic reconstruction of dual-energy unenhanced brain computed tomography in children: comparison of image quality against standard mono-energetic images and conventional polychromatic computed tomography.

Background: Advanced virtual monochromatic reconstruction from dual-energy brain CT has not been evaluated in children.

Objective: To determine the most effective advanced virtual monochromatic imaging energy level for maximizing pediatric brain parenchymal image quality in dual-energy unenhanced brain CT and to compare this technique with conventional monochromatic reconstruction and polychromatic scanning.

Materials And Methods: Using both conventional (Mono) and advanced monochromatic reconstruction (Mono+) techniques, we retrospectively reconstructed 13 virtual monochromatic imaging energy levels from 40 keV to 100 keV in 5-keV increments from dual-source, dual-energy unenhanced brain CT scans obtained in 23 children.

Modified Dual-Energy Algorithm for Calcified Plaque Removal: Evaluation in Carotid Computed Tomography Angiography and Comparison With Digital Subtraction Angiography.

Objectives: Computed tomography angiography (CTA) is a valuable tool for the assessment of carotid artery stenosis. However, blooming artifacts from calcified plaques might result in an overestimation of the stenosis grade. The aim of this study was to investigate a new dual-energy computed tomography (DECT) technique with a modified 3-material decomposition algorithm for calcium removal in extracranial carotid artery stenosis.

Photon-counting CT for simultaneous imaging of multiple contrast agents in the abdomen: An in vivo study.

Purpose: To demonstrate the feasibility of spectral imaging using photon-counting detector (PCD) x-ray computed tomography (CT) for simultaneous material decomposition of three contrast agents in vivo in a large animal model.

Methods: This Institutional Animal Care and Use Committee-approved study used a canine model. Bismuth subsalicylate was administered orally 24-72 h before imaging.

Computed Tomography of the Head and Neck Region for Tumor Staging-Comparison of Dual-Source, Dual-Energy and Low-Kilovolt, Single-Energy Acquisitions.

Purpose: The aim of this study was to intra-individually compare the image quality obtained by dual-source, dual-energy (DSDE) computed tomography (CT) examinations and different virtual monoenergetic reconstructions to a low single-energy (SE) scan.

Materials And Methods: Third-generation DSDE-CT was performed in 49 patients with histologically proven malignant disease of the head and neck region. Weighted average images (WAIs) and virtual monoenergetic images (VMIs) for low (40 and 60 keV) and high (120 and 190 keV) energies were reconstructed.

Potential of gadolinium as contrast material in second generation dual energy computed tomography - An ex vivo phantom study.

Purpose: To evaluate the potential of gadolinium (Gd) as contrast material (CM) in second generation dual energy computed tomography (DECT).

Material And Methods: In a phantom model, DECT post-processing was used to increase Gd attenuation using advanced monoenergetic extrapolation (MEI), to create virtual non-contrast images (Gd-VNC) and Gd maps and to quantify Gd content. Dilutions of Gd and iodinated CM (7-296 HU) were filled in syringes, placed in an attenuation phantom and scanned with standard DECT protocols (80 &100/Sn140 kV).