Diagnostic accuracy of dual-source multi-slice CT-coronary angiography in patients with an intermediate pretest likelihood for coronary artery disease.

Aims: The aim of the present study was to assess the clinical performance of a dual X-ray source multi-slice CT (MSCT) with high temporal resolution to assess the coronary status in patients with an intermediate pretest likelihood for significant coronary artery disease (CAD) without using negative chronotropic pretreatment.

Methods And Results: Dual-source CT (DSCT) angiography (Siemens Definition) was performed in 90 patients with an intermediate likelihood for CAD who were referred for invasive coronary angiography. DSCT generated data sets with diagnostic image quality in 88 of the overall 90 patients.

Optimization of contrast material administration for electrocardiogram-gated computed tomographic angiography of the chest.

Objective: Electrocardiogram-gated computed tomographic angiography is increasingly used in the differential diagnosis of acute chest pain. We studied the optimal timing of contrast material injection using a test bolus and a bolus-tracking technique.

Materials And Methods: Thirty patients were prospectively included in the study.

[Dual-source cardiac CT imaging with improved temporal resolution: Impact on image quality and analysis of left ventricular function].

In a newly developed dual-source computed tomography system (DSCT) the relation of heart rate and image quality and the possible advantages of the system's superior temporal resolution in the evaluation of left ventricular parameters as compared to results of cardiac magnetic resonance imaging (MRI) were assessed. Coronary CT angiography was performed using a DSCT (Somatom Defintion, Siemens Medical Solutions, Forchheim, Germany) in 21 patients (mean age 62+/-8; 15 male, 6 female). Image quality of the coronary arteries, the heart valves, and the left ventricular myocardium was assessed using a three-point grading scale.

Comparison of progression of coronary calcium in postmenopausal women on versus not on estrogen/progestin therapy.

The prophylactic effect of postmenopausal hormone replacement therapy on coronary atherosclerosis remains controversial. We, therefore, examined the influence of combined estrogen/progestin therapy on the progression of coronary calcium as a marker of coronary atherosclerosis. We determined the extent of coronary calcium in 277 women (age 57 +/- 6 years, time after menopause 3.

Multislice computed tomography for determination of coronary artery disease in a symptomatic patient population.

Background: Multislice computed tomography (MSCT) has started to replace Electron beam CT for quantitation of coronary artery calcium. However no study has evaluated the diagnostic accuracy of MSCT for prediction of coronary artery disease (CAD) in a symptomatic patient population using the volume score.

Methods And Results: 1347 symptomatic subjects (male = 803, mean age = 62 years) with suspected CAD underwent MSCT studies 1 +/- 2 days before the coronary angiogram.

Effects of search mode and intertrial priming on singleton search.

There is no consensus as to what information guides search for a singleton target. Does the most salient display element capture attention, regardless of the observer's attentional set? Do observers adopt a default salience-based search mode? Does knowledge of the target's defining featural property (when available) affect search? Finally, can intertrial contingencies account for the disparate results in the literature? We investigated search for a shape singleton when (1) the target and nontarget shapes switched unpredictably from trial to trial, (2) the target feature remained fixed, and (3) the target was a singleton on only one third of the trials. We examined overall reaction times, search slopes, errors, and the magnitude of the slowing caused by a cross-dimensional singleton distractor.

Assessment of coronary artery stent patency and restenosis using 64-slice computed tomography.

Rationale And Objectives: Restenosis remains a major limitation of coronary catheter-based stent placement. Therefore, a reliable noninvasive diagnostic method for the evaluation of stented coronary arteries would be highly desirable. Our aim was to evaluate the diagnostic accuracy of high-resolution 64-slice computed tomography (64SCT) in a pilot study for the assessment of the lumen of coronary artery stents.

Accuracy of 64-MDCT in the diagnosis of ischemic heart disease.

Objective: The aim of this study was to evaluate the potential clinical value of a new generation of 64-MDCT systems with that of invasive coronary angiography in the diagnosis of coronary artery disease (CAD).

Subjects And Methods: Seventy-two consecutive patients with known or suspected CAD underwent both 64-MDCT and quantitative coronary angiography (QCA). A CT system with acquisition of 64 slices per gantry rotation was used with a spatial resolution of 0.

Dual-source CT cardiac imaging: initial experience.

The relation of heart rate and image quality in the depiction of coronary arteries, heart valves and myocardium was assessed on a dual-source computed tomography system (DSCT). Coronary CT angiography was performed on a DSCT (Somatom Definition, Siemens) with high concentration contrast media (Iopromide, Ultravist 370, Schering) in 24 patients with heart rates between 44 and 92 beats per minute. Images were reconstructed over the whole cardiac cycle in 10% steps.

It's under control: top-down search strategies can override attentional capture.

Bacon and Egeth (1994) proposed that observed instances of attentional capture by feature singletons (e.g., color) were the result of a salience-based strategy adopted by subjects (singleton detection mode) and, thus, were not automatic.

Image quality, motion artifacts, and reconstruction timing of 64-slice coronary computed tomography angiography with 0.33-second rotation speed.

Objectives: We sought to evaluate the impact of patients' heart rate (HR) on coronary CTA image quality (IQ) and motion artifacts using a 64-slice scanner with 0.33/360 degrees rotation.

Materials And Methods: Coronary CTA data sets of 32 patients (HR 65 bpm to 75 bpm, n = 7) examined on a 64-slice scanner (Sensation 64, Siemens Medical Solutions, Forchheim, Germany) with 0.

Visual quality determines the direction of neural repetition effects.

One ubiquitous finding in functional magnetic resonance imaging studies is that repeated stimuli elicit lower responses than novel stimuli. In apparent contradiction, some studies have reported the exact opposite effect--greater responses to repeated than novel stimuli--in many of the same brain regions. Interestingly, these latter enhancement effects are typically obtained when stimuli have been degraded.

Accuracy of 64-slice computed tomography to classify and quantify plaque volumes in the proximal coronary system: a comparative study using intravascular ultrasound.

Objectives: We evaluated the accuracy of a new 64-slice computed tomography (CT) scanner, compared with intravascular ultrasound, to visualize atherosclerosis in the proximal coronary system.

Background: Noninvasive determination of plaque composition and plaque burden may be important to improve risk stratification.

Methods: In 20 patients, a 64-slice CT scan (Sensation 64, Siemens Medical Solutions, Forchheim, Germany) and an intravascular ultrasound investigation of vessels without stenosis >50% was performed.

[Prediction of serious cardiovascular events by determining coronary artery calcification measured by multi-slice computed tomography].

Background: The efficacious prophylaxis of myocardial infarction requires an accurate identification of patients at risk. Conventional risk stratification is often insufficient for this. We therefore examined the predictive value of coronary calcifications for future cardiovascular events.

Quantification of obstructive and nonobstructive coronary lesions by 64-slice computed tomography: a comparative study with quantitative coronary angiography and intravascular ultrasound.

Objectives: The aim of the present study was to determine the diagnostic accuracy of 64-slice computed tomography (CT) to identify and quantify atherosclerotic coronary lesions in comparison with catheter-based angiography and intravascular ultrasound (IVUS).

Background: Currently, the ability of multislice CT to quantify the degree of coronary artery stenosis and dimensions of coronary plaques has not been evaluated.

Methods: We included 59 patients scheduled for coronary angiography due to stable angina pectoris.

Visualising noncalcified coronary plaques by CT.

Due to a rapid improvement of the new generation submillimetre multislice CT-technology noninvasive tomographic imaging of the coronary vessel wall has become reality. First clinical studies have shown the ability in particular of 16-slice CT to determine plaque burden, plaque composition and compensatory vessel-wall remodelling. These novel findings already constitute an important step forward to assess coronary atherosclerosis noninvasively in a detailed manner which opens promising new opportunities for a better understanding and riskstratification of coronary atherosclerosis.

Coordination of voluntary and stimulus-driven attentional control in human cortex.

Visual attention may be voluntarily directed to particular locations or features (voluntary control), or it may be captured by salient stimuli, such as the abrupt appearance of a new perceptual object (stimulus-driven control). Most often, however, the deployment of attention is the result of a dynamic interplay between voluntary attentional control settings (e.g.

[Detection and characterization of atherosclerotic coronary plaques with multislice spiral computed tomography].

Provided that adequate image quality is achieved, contrast-enhanced multislice spiral computed tomography enables the identification and characterisation of calcified and non-calcified coronary plaques. This is a major advance in the non-invasive assessment of coronary atherosclerosis that promises to open up new opportunities for a better understanding and risk stratification of this condition, with visualization of non-calcified hypodense lesions in particular appearing to be of prognostic importance. Current limitations of the technique relating mainly to temporal and spatial resolution may be eliminated by the introduction of a new generation of scanners enabling 64 slices and more.

[Coronary calcifications and the diagnosis of coronary artery disease].

Coronary calcium is a sensitive marker of coronary atherosclerosis, even at an early stage. With the aid of multislice computed tomography, noninvasive visualization of the microcalcification is possible. This enables the identification of asymptomatic patients at risk of developing future cardiovascular disease, and the initiation of effective preventive measures.

[Technique and possibilities of cardiac computed tomography].

Electron beam computed tomography no longer has a role to play in Germany. In contrast, multidetector spiral CT has great potential for replacing some coronary catheter studies, in particular for the exclusion of coronary artery disease, and this in particular since the forthcoming introduction of a 64-slice MDCT scanner promises a further improvement in temporal and special resolution. Currently, however it is no alternative to invasive angiography, since quantification of coronary stenoses is not possible; nor can a diagnostic evaluation be made in the presence of coronary calcifications or intracoronary stents.

Effects of task relevance and stimulus-driven salience in feature-search mode.

Attentional allocation in feature-search mode (W. F. Bacon & H.

[Diabetes mellitus type 2: coronary calcifications as a predictor of coronary artery disease].

Background And Purpose: Patients with diabetes mellitus have an increased risk of developing cardiovascular disease. Therefore, coronary artery disease (CAD) is the most common cause of mortality in these patients. The early and reliable diagnosis of coronary atherosclerosis is crucial for an effective treatment.

Relation of coronary calcium scores by electron beam tomography to obstructive disease in 2,115 symptomatic patients.

This angiographically correlated study reports on, for the first time, age- and gender-based distribution of the volumetric calcium score in a large group of patients with suspected coronary artery disease. Volumetric calcium data predicted significant coronary artery disease (>/=50% lumen diameter stenosis) as well as the traditional Agatston score. Exclusion of any calcium was highly accurate in ruling out obstructive disease in symptomatic subjects >/=50 years of age.

Accuracy of multidetector spiral computed tomography in identifying and differentiating the composition of coronary atherosclerotic plaques: a comparative study with intracoronary ultrasound.

Objectives: We evaluated the accuracy of contrast-enhanced multidetector spiral computed tomography (MDCT) for the noninvasive detection and classification of coronary plaques and compared it with intracoronary ultrasound (ICUS).

Background: Noninvasive determination of plaque composition and plaque burden may be important to improve risk stratification and to monitor progression of coronary atherosclerosis.

Methods: We included 46 consecutive patients with a distinctive risk profile, who were investigated by ICUS (Goldvision, 20 MHz, Jomed Inc.

[Evaluating multislice computed tomography for imaging coronary atherosclerosis].

Purpose: The purpose of this study was the evaluation of multidetector-row computed tomography (MDCT) for the assessment of atherosclerotic coronary artery vessel wall changes.

Methods: In an ex vivo study, 17 human hearts were scanned with MDCT and results were compared to histopathology. Morphologic imaging criteria of MDCT for various plaque-types were developed.