Radiation dose considerations by intra-individual Monte Carlo simulations in dual source spiral coronary computed tomography angiography with electrocardiogram-triggered tube current modulation and adaptive pitch.

Objectives: To evaluate radiation dose levels in patients undergoing spiral coronary computed tomography angiography (CTA) on a dual-source system in clinical routine.

Methods: Coronary CTA was performed for 56 patients with electrocardiogram-triggered tube current modulation (TCM) and heart-rate (HR) dependent pitch adaptation. Individual Monte Carlo (MC) simulations were performed for dose assessment.

Which concentration to choose in dual flow cardiac CT?: dual flow cardiac CT.

Purpose: An extensive number of protocols have been suggested to allow for functional diagnostics; however, no data is available about the minimal amount of contrast medium to achieve reliable imaging properties. None of the plethora of existing studies report a rational why the specific concentration was chosen.

Materials And Methods: A total of 40 patients were included in this prospective, controlled study.

High-pitch spiral computed tomography: effect on image quality and radiation dose in pediatric chest computed tomography.

Objectives: computed tomography (CT) is considered the method of choice in thoracic imaging for a variety of indications. Sedation is usually necessary to enable CT and to avoid deterioration of image quality because of patient movement in small children. We evaluated a new, subsecond high-pitch scan mode (HPM), which obviates the need of sedation and to hold the breath.

Individually adapted, interactive multiplanar reformations vs. semi-automated coronary segmentation and curved planar reformations for stenosis detection in coronary computed tomography angiography.

Objective: To evaluate, whether semi-automated vessel extraction and curved planar reformations ("automated vessel extraction") increases diagnostic accuracy in the detection of relevant coronary artery lesions compared to manual, interactive multiplanar interpretation ("manual approach").

Materials And Methods: 50 coronary CT angiography datasets were evaluated by four independent readers (two experienced, two novice) for the presence of stenoses exceeding 50% diameter reduction. One experienced and one novice reader each used the "manual approach" for cases 1-25 and "automated vessel extraction" for cases 26-50, while the other two readers used the complementary method.

Influence of slice thickness and reconstruction kernel on the computed tomographic attenuation of coronary atherosclerotic plaque.

Background: The computed tomographic (CT) attenuation of coronary atherosclerotic plaque has been proposed as a marker for tissue characterization and may thus potentially contribute to the assessment of plaque instability.

Objective: We analyzed the influence of reconstruction parameters on CT attenuation measured within noncalcified coronary atherosclerotic lesions.

Methods: Seventy-two patients were studied by contrast-enhanced dual-source CT coronary angiography (330 millisecond rotation time, 2 x 64 x 0.

Coronary computed tomography angiography with a consistent dose below 1 mSv using prospectively electrocardiogram-triggered high-pitch spiral acquisition.

Aims: We evaluated the feasibility and image quality of a new scan mode for coronary computed tomography angiography (CTA) with an effective dose of less than 1 mSv.

Methods And Results: In 50 consecutive patients (body weight View Article and Find Full Text PDF

Radiation exposure and image quality in staged low-dose protocols for coronary dual-source CT angiography: a randomized comparison.

Objective: To evaluate staged low-dose approaches for coronary CT angiography (CTA) in which a standard sequence was added if the low-dose sequence did not allow reliable rule-out of coronary stenosis.

Patients And Methods: A total of 176 consecutive patients referred for dual-source CTA were randomized to three protocols: group 1 using prospective ECG-triggering (100 kV, 330 mAs), group 2 a retrospectively gated "MinDose" sequence (100 kV, 330 mAs) and group 3 a standard spiral sequence (120 kV, 400 mAs). If image quality in low-dose groups 1 or 2 was non-diagnostic, an additional standard CT examination (as in group 3) was performed.

Prospectively ECG-triggered high-pitch spiral acquisition for coronary CT angiography using dual source CT: technique and initial experience.

Objective: We evaluated radiation exposure and image quality of a new coronary CT angiography protocol, high-pitch spiral acquisition, using dual source CT (DSCT).

Material And Methods: Coronary CTAwas performed in 25 consecutive patients with a stable heart rate of 60 bpm or less after premedication, using 2 x 128 0.6-mm sections, 38.

Randomized comparison of 64-slice single- and dual-source computed tomography coronary angiography for the detection of coronary artery disease.

Objectives: The purpose of this study was to analyze the influence of a systematic approach to lower heart rate for coronary computed tomography (CT) angiography on diagnostic accuracy of 64-slice single- and dual-source CT.

Background: Coronary CT angiography is often impaired by motion artifacts, so that routine lowering of heart rate is usually recommended. This is often conceived as a major limitation of the technique.

High-pitch spiral acquisition: a new scan mode for coronary CT angiography.

Coronary CT angiography allows high-quality imaging of the coronary arteries when state-of-the-art CT systems are used. However, radiation exposure has been a concern. We describe a new scan mode that uses a very high-pitch spiral acquisition, "Flash Spiral," which has been developed specifically for low-dose imaging with dual-source CT.

Noninvasive assessment of coronary in-stent restenosis by dual-source computed tomography.

Assessment of coronary artery stents using computed tomographic angiography has been challenging. The technology of dual-source computed tomography (DSCT) provides higher temporal resolution that may allow more accurate evaluation of coronary stents. This study evaluated the accuracy of DSCT for the assessment of coronary artery in-stent restenosis.

Functional cardiac CT imaging: a new contrast application strategy for a better visualization of the cardiac chambers.

Purpose: Evaluation of a new protocol for Dual-source CT contrast-enhanced cardiac imaging for better visualization of right ventricle structures.

Methods: A total of 106 patients were included in this prospective, controlled study. The control group (n=53) underwent our clinic's standard procedure for contrast-enhanced imaging of coronary arteries.

Imaging of extralobar pulmonary sequestration in a patient with tetralogy of Fallot with pulmonary atresia, ventricular septal defect and multiple aorto-pulmonary collateral arteries with multidetector computed tomography.

Complex pulmonary vascular blood supply is common in patients with tetralogy of Fallot with pulmonary atresia, major systemic to pulmonary collateral arteries and hypoplastic or deficient central pulmonary arteries. An extralobar lung sequestration, which has not been described previously in these patients, was imaged in a 6-week-old infant with multidetector computed tomography with sub-millimeter resolution. Arterial and venous vessels were analyzed using three-dimensional vascular exploration tools and results were confirmed with cardiac catheterization.

Advances in imaging protocols for cardiac MDCT: from 16- to 64-row multidetector computed tomography.

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in the Western world. Since the majority of all invasive diagnostic coronary angiography procedures are not followed by therapeutic interventions, interest is growing in noninvasive technologies to diagnose and visualize CAD. The most promising of these is multislice spiral computed tomography (MSCT), which can visualize human coronary arteries in vivo noninvasively.

Influence of heart rate on the diagnostic accuracy of dual-source computed tomography coronary angiography.

Objectives: We evaluated the influence of heart rate on image quality and diagnostic accuracy of dual-source computed tomography (DSCT) coronary angiography.

Background: Multidetector computed tomography (MDCT) coronary angiography has demonstrated an inverse relationship between heart rate and image quality. Dual-source CT provides a higher temporal resolution.

Late enhancement using multidetector row computer tomography: a feasibility study with low dose 80 kV protocol.

Aims: Detecting stenoses of coronary arteries with multidetector row computer tomography (MDCT) is a well feasible non-invasive method. However, there is still the problem of deciding whether a stenosis is hemodynamically relevant or not. Objective of the present study was to validate the feasibility of a low dose protocol for MDCT using 80 kV for detecting late enhancement.

High-resolution reconstruction of a waxed heart specimen with flat panel volume computed tomography and rapid prototyping.

A waxed piglet heart was scanned with a flat panel volume computed tomography scanner (voxel size, 0.25 mm). Virtual and real laser-sintered models showed excellent visual concordance with the original.

Diagnostic accuracy of multislice computed tomography for the detection of coronary artery disease in diabetic patients.

Background: Diabetes mellitus is an important risk factor for coronary artery disease. Cardiac multislice computed tomography (MSCT) permits visualization of the coronary arteries with good sensitivity and specificity. However, at present, there are no data whether MSCT allows an accurate assessment of coronary arteries of diabetic patients, in comparison to nondiabetic patients.

Influence of a lipid-lowering therapy on calcified and noncalcified coronary plaques monitored by multislice detector computed tomography: results of the New Age II Pilot Study.

Purpose: Multislice detector computed tomography (MSCT) is an accurate noninvasive modality to detect and classify different stages of atherosclerosis. The aim of the New Age II Study was to detect coronary lesions in men without established coronary artery disease (CAD) but with a distinct cardiovascular risk profile. We also sought to assess the effect after 1 year of a lipid-lowering therapy (LLT) using 20 mg of atorvastatin.

Diagnostic accuracy of noninvasive coronary angiography in patients after bypass surgery using 64-slice spiral computed tomography with 330-ms gantry rotation.

Background: Multidetector computed tomographic angiography (MDCT) has been shown to allow detection of coronary artery bypass graft (CABG) occlusions and stenoses. However, the assessment of native coronary arteries in addition to CABG has thus far not been sufficiently validated.

Methods And Results: Fifty patients with a total of 138 CABG (34 mammary grafts, 3 radial grafts, 101 venous grafts) were investigated by MDCT (0.

Assessment of coronary artery stent restenosis by 64-slice multi-detector computed tomography.

Aims: We investigated the feasibility of assessing coronary artery stent restenosis using a new generation 64-slice multi-detector computed tomography-scanner (MDCT) in comparison to conventional quantitative angiography.

Methods And Results: MDCT was performed in 64 consecutive patients (mean age 58+/-10 years) with previously implanted coronary artery stents (102 stented lesions: mean stent diameter 3.17+/-0.

Imaging of aortopulmonary collateral arteries with high-resolution multidetector CT.

Background: Precise visualization of the pulmonary vasculature is mandatory for adequate treatment of patients with pulmonary atresia and ventricular septal defect (PA-VSD). Aortopulmonary collateral arteries (APCs) can be visualized by selective injections of contrast agent in the catheterization laboratory.

Objective: To evaluate multidetector CT (MDCT) and different image postprocessing methods for analysis of complex pulmonary blood supply in patients with PA-VSD.

Evaluation of cardiac function and myocardial viability with 16- and 64-slice multidetector computed tomography.

Retrospectively ECG-gated MDCT shows a high correlation and acceptable agreement of left-ventricular functional parameters compared to MR imaging. Thus, in addition to the non-invasive evaluation of coronary arteries, further important additional information of left-ventricular functional parameters with clinical and prognostic relevance can be achieved by one single MDCT examination. For assessment of myocardial viability, low-dose CT late enhancement scanning is feasible, and preliminary results look promising.

Contrast-enhanced coronary artery visualization by dual-source computed tomography--initial experience.

Unlabelled: Multi-detector computed tomography (CT) scanners, by virtue of their high temporal and spatial resolution, permit imaging of the coronary arteries. However, motion artifacts, especially in patients with higher heart rates, can impair image quality. We thus evaluated the performance of a new dual-source CT (DSCT) with a heart rate independent temporal resolution of 83 ms for the visualization of the coronary arteries in 14 consecutive patients.