Search

Supplemental digital content is available in the text.

The purpose of this study was to evaluate the accuracy of noninvasive reconstructions of epicardial potentials, electrograms, activation and recovery isochrones, and beat origins by simultaneously performing electrocardiographic imaging (ECGI) and invasive epicardial electrography in intact animals.

Purpose:To assess and quantify the magnitude and direction of respiratory movement of the aorta and origins of its side branches. Methods:A quantitative 3-dimensional (3D) subtraction analysis of computed tomography (CT) scans during inspiration and expiration was performed to determine the respiratory geometric movements of the aorta and side branches in 60 patients. During breath-hold expiration and inspiration, 1-mm-thick CT slices of the aorta were acquired in unenhanced and contrast-enhanced scans. The datasets were compared using dedicated multiplanar reformation image subtraction software to determine the change in position of relevant anatomic sections, including the ascending thoracic aorta (AA), the origins of the brachiocephalic artery (BA) and left subclavian artery (LSA), the descending thoracic aorta (DTA) at the level of the tenth thoracic vertebra, as well as the origins of the celiac trunk, superior mesenteric artery, and the renal arteries. Results:Complex movement was visible during inspiration; the regions of interest in the thoracic aorta and side branches moved in the anterior, medial, and caudal directions compared with the expiration state. Mean 3D movement vectors (± standard deviation) were 8.9±3.6 mm (AA), 12.0±4.1 mm (BA), 11.1±3.9 mm (LSA), and 4.9±2.5 mm (DTA). Abdominal side branches moved in the caudal direction 1.3±1.1 mm. There was significantly less movement in the DTA compared to AA (p<0.001). The correlation coefficient between the extent of LSA movement and thoracic excursion was 0.78. Conclusion:The aorta and side branches undergo considerable respiratory movement. The results from this study provide an important contribution to understanding aortic dynamics.

The aims of this study were to test high-flow application of contrast media (CM) using novel high-flow needles and to assess injection- and flow-related parameters in a circulation phantom and in an in vivo population.

Using smaller volumes of contrast media (CM) in CT angiography (CTA) is desirable in terms of cost reduction and prevention of contrast-induced nephropathy (CIN). The purpose was to evaluate the feasibility of low CM volume in CTA of the aorta.

Iodinated contrast media (CM) in computed tomographic angiography is characterized by its concentration and, consecutively, by its viscosity. Viscosity itself is directly influenced by temperature, which will furthermore affect injection pressure. Therefore, the purposes of this study were to systematically evaluate the viscosity of different CM at different temperatures and to assess their impact on injection pressure in a circulation phantom.

Both iodine delivery rate (IDR) and iodine concentration are decisive factors for vascular enhancement in computed tomographic angiography. It is unclear, however, whether the use of high–iodine concentration contrast media is beneficial to lower iodine concentrations when IDR is kept identical. This study evaluates the effect of using different iodine concentrations on intravascular attenuation in a circulation phantom while maintaining a constant IDR.

Aims Epicardial adipose tissue (EAT) volume has been associated with coronary artery disease (CAD). As diabetes mellitus type 2 (DM2) patients have higher EAT volumes, it has been suggested that EAT may play a role in promoting CAD in these patients. The aim of this study was to examine the association between EAT and CAD in DM2, impaired fasting glucose (IFG) and control patients presenting with stable chest pain. Methods and results A total of 410 stable chest pain patients underwent multidetector cardiac computed tomography angiography (CCTA) to assess the presence of CAD. The extent of CAD was expressed as the number of affected segments. The EAT volume was measured using three-dimensional volumetric quantification. The EAT was compared using ANOVA, logistic and linear regression models were used to assess its predictive value. Multivariable regression analysis corrected for traditional risk factors was performed. Eighty-three patients had DM2, 118 IFG and there were 209 controls. DM2 as well as IFG patients had higher EAT volumes compared with controls (98 ± 41, 92 ± 39, and 75 ± 34 cm3, respectively; P < 0.001). EAT predicted the presence (OR: 1.01; P < 0.001) and the extent of CAD (B: 0.01; P < 0.001). The associations were equal in all subgroups. However, in a multivariable regression model corrected for traditional cardiovascular risk factors, EAT was not an independent predictor for the presence or extent of CAD (OR: 1.00; P = 0.88 and B: −0.11; P = 0.68, respectively). Conclusion The EAT volume is associated with CAD in DM2, IFG, and control patients. However, EAT is not an independent predictor for CAD in patients presenting with stable chest pain.

Objective —Cardiac computed tomography (CT) and conventional biplane ventriculography are established methods for the determination of ventricular function. Recently dual source CT was introduced for cardiac CT scanning providing a temporal resolution of 83ms independent of the patient’s heart rate.The purpose of this study was to assess the global left ventricular function using retrospectively ECG-gated dual source computed tomography (DSCT) in comparison to conventional ventriculography.Methods and results —Contrast-enhanced cardiac DSCT and conventional ventriculography were performed in 10 domestic pigs with an approximate weight of 60kg using standardized examination protocols under general anaesthesia. From manually drawn endocardial contours, LV end-systolic (ESV) and end-diastolic volume (EDV), stroke volume (SV), ejection fraction (EF) were calculated by means of dedicated analysis software separately for both examination modalities. LV functional parameters were analysed using Bland-Altman plots, Student t-test, and Pearson correlation coefficient. Left ESV and EDV determined with DSCT correlated well with conventional ventriculography results (ESV: r=0.86; EDV: r=0.72) with a good correlation also for SV (r=0.67).An only moderate correlation was found for EF (r=0.52). Student t-test showed a significant underestimation of SV and EF derived from DSCT in comparison to ventriculography.Conclusion —Retrospectively ECG-gated DSCT can accurately determine LV volumes in comparison to conventional ventriculography but provides lower SV and EF values; however, the correlation was only moderate.

Accurate measurement is crucial for the assessment of tumor dimensions to allow accurate evaluation of tumor response. Thus, the purpose of our study was to assess the accuracy of semi-automated RECIST and volumetric measurements of liver lesions in a liver phantom with different CT acquisition parameters.

To develop a circulation phantom with physiologic circulation parameters, including a pulmonary and a body circulation for the evaluation of intravascular contrast material (CM) application.

Chronic respiratory diseases are one of the leading causes of death and morbidity. Therefore the assessment of regional and global ventilation distribution together with pulmonary perfusion imaging becomes more and more important. To date either radionuclide ventilation scintigraphy or high-resolution computed tomography (HR-CT) are used for ventilation assessment and pulmonary parenchyma analysis. But scintigraphy lacks spatial and temporal resolution while HR-CT applies radiation and lacks functional analysis. Over the last years Magnetic resonance imaging (MRI) of the lung has evolved by using aerosolized contrast agents. MRI offers morphological and functional information and does not apply radiation dose. Approaches to use hyperpolarized gases like Xenon and Helium have been made, but these gases are complex and expensive to produce and use. Lately the use of widely available contrast agents like gadolinium chelates has been investigated. As no special MR hardware is needed and gadolinium is straightforward to apply this new method yields promising results for the future. This review is to give an overview about current developments and methods in Gadolinium-enhanced MR ventilation.

We sought to evaluate the ability of retrospectively ECG-gated dual-source computed tomography (DSCT) to assess left (LV) and right ventricular (RV) functional parameters in comparison to 1.5 T magnetic resonance imaging (MRI).

We aimed to evaluate the feasibility and performance of a computer-aided detection (CAD) tool for automated detection of segmental and subsegmental pulmonary emboli.

The accuracy of automated volumetry for pulmonary nodules in a phantom using different CT scanner technologies from single-slice spiral CT (SSCT) to 64-slice multidetector-row CT (MDCT) was compared.

We sought to compare an 80-kVp coronary calcium scoring protocol with the standard protocol of 120 kVp in terms of accuracy and reproducibility and to assess its dose reduction potential.

We sought to investigate the influence of heart rate and temporal resolution on the assessment of left-ventricular (LV) function with multislice spiral computed tomography (CT).

To compare coronary calcium scoring results (calcium volume, calcium mass, Agatston score, and number of lesions) of different slice thicknesses using a 16-slice CT (MSCT) scanner.

We sought to assess the agreement of coronary artery calcium score in nonenhanced and contrast-enhanced multislice-spiral computed tomography.