Right atrial scar detection after catheter ablation: Comparison of 2D and high spatial resolution 3D-late enhancement magnetic resonance imaging.

Rationale And Objectives: To prospectively compare the diagnostic performance of two-dimensional (2D) and high spatial resolution three-dimensional (3D) late enhancement magnetic resonance imaging (MRI) for the detection of scar tissue caused by catheter ablation of the right atrium in patients with atrial flutter.

Materials And Methods: Forty-seven patients were enrolled. In 16 patients, imaging of the cavotricuspid isthmus was performed before and after catheter ablation, 16 subjects were imaged before, and 15 after catheter ablation, resulting in a total of 63 examinations.

T1-weighted MRI for the detection of coronary artery plaque haemorrhage.

Objective: Hyperintense areas in atherosclerotic plaques on pre-contrast T1-weighted MRI have been shown to correlate with intraplaque haemorrhage. We evaluated the presence of T1 hyperintensity in coronary artery plaques in coronary artery disease (CAD) patients and correlated results with multi-detector computed tomography (MDCT) findings.

Methods: Fifteen patients with CAD were included.

MRI of right atrial function after catheter ablation of atrial flutter.

Rationale And Objectives: Catheter ablation of the cavotricuspid isthmus (CTI) is an effective treatment of right atrial flutter. The objective of this study was to evaluate the changes in CTI length and right atrial (RA) function after radiofrequency ablation of isthmus-dependent atrial flutter (isthmus ablation).

Materials And Methods: Magnetic resonance imaging was obtained in 14 patients (2 female, mean age 59 +/- 9) before and after isthmus ablation (mean delay 80 +/- 175 days) using steady-state free precession cine magnetic resonance imaging in right anterior oblique view orientation.

Diastolic isthmus length and 'vertical' isthmus angulation identify patients with difficult catheter ablation of typical atrial flutter: a pre-procedural MRI study.

Aims: Catheter ablation of isthmus-dependent atrial flutter is technically demanding in some patients and extremely simple in others. The intervention targets a defined anatomical structure, the so-called cavotricuspid isthmus (CTI). We sought to characterize CTI anatomy in vivo in patients with difficult and simple catheter ablation of atrial flutter.

Update on multidetector coronary CT angiography of coronary stents: in vitro evaluation of 29 different stent types with dual-source CT.

The aim of this study was to test a large sample of the latest coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in dual-source multidetector row CT (DSCT) in vitro and to provide a CT catalogue of currently used coronary artery stents. Twenty-nine different coronary artery stents (19 steel, 6 cobalt-chromium, 2 tantalum, 1 iron, 1 magnesium) were examined in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70 HU). Stents were imaged in axial orientation with standard parameters: 32 x 0.

MR imaging of thrombi using EP-2104R, a fibrin-specific contrast agent: initial results in patients.

This study was an initial phase II trial in humans of molecular magnetic resonance (MR) imaging for improved visualization of thrombi in vessel territories potentially responsible for stroke using a new fibrin-specific contrast agent (EP-2104R). Eleven patients with thrombus in the left ventricle (n = 2), left or right atrium (n = 4), thoracic aorta (n = 4) or carotid artery (n = 1) as verified by an index examination (ultrasound, computed tomograpy, or conventional MR) were enrolled. All MR imaging was performed on 1.

Intraindividual comparison of 3D coronary MR angiography and coronary CT angiography.

Rationale And Objectives: To compare the diagnostic value of magnetic resonance (MR) and computed tomography (CT) for the detection of coronary artery disease (CAD) with special regard to calcifications.

Materials And Methods: Twenty-seven patients with known CAD were examined with a targeted, navigator-gated, free-breathing, steady-state free precession MR angiography sequence (repetition time = 5.6 milliseconds, echo time = 2.

Assessment of regional left ventricular function with multidetector-row computed tomography versus magnetic resonance imaging.

This study compares quantitative and qualitative information on global and regional left ventricular (LV) function obtained with multidetector-row computed tomography (MDCT) with that obtained with magnetic resonance imaging (MRI) in patients with a high prevalence of LV wall motion abnormalities. Thirty patients (19 male, 63.7+/-15.

Selective coronary artery plaque visualization and differentiation by contrast-enhanced inversion prepared MRI.

Aims: We sought to evaluate the utility of contrast-enhanced coronary magnetic resonance imaging (CE-MRI) for selective visualization and non-invasive differentiation of atherosclerotic coronary plaque in humans.

Methods And Results: Nine patients with coronary artery disease (CAD) as confirmed by X-ray angiography and multidetector computed tomography (MDCT) were studied by T1-weighted black blood inversion recovery coronary MRI before (N-IR) and after administration of Gd-DTPA (CE-IR). Plaques were categorized as calcified, non-calcified, and mixed based on their Hounsfield number derived from MDCT.

MDCT determination of volume and function of the left ventricle: are short-axis image reformations necessary?

Objective: Determination of left ventricular (LV) volumes and global function parameters from MDCT data sets is usually based on short-axis reformations from primarily reconstructed axial images, which prolong postprocessing time. The aim of this study was to evaluate the feasibility of LV volumetry and global LV function assessment from axial images in comparison with short-axis image reformations.

Subjects And Methods: This study consisted of 20 patients with either coronary artery disease or dilated cardiomyopathy.

64- Versus 16-slice CT angiography for coronary artery stent assessment: in vitro experience.

Objectives: We sought to assess the visualization of different coronary artery stents and the delineation of in-stent stenoses using 64- and 16-slice multidector computed tomography (MDCT).

Materials And Methods: A total of 15 different coronary stents with a simulated in-stent stenosis were placed in a vascular phantom and scanned with a 16-slice and a 64-slice MDCT at orientations of 0 degree, 45 degrees, and 90 degrees relative to the scanner's z-axis. Visible lumen diameter and attenuation in the stented and the unstented segment of the phantom were measured.

64-slice multidetector coronary CT angiography: in vitro evaluation of 68 different stents.

The purpose of this study was to test a large sample of different coronary artery stents using four image reconstruction approaches with respect to lumen visualization, lumen attenuation, and image noise in 64-slice multidetector-row computed tomography (MDCT) in vitro and to provide a catalogue of currently used coronary artery stents when imaged with state-of the-art MDCT. We examined 68 different coronary artery stents (57 stainless steel, four cobalt-chromium, one cobalt-alloy, two nitinol, four tantalum) in a coronary artery phantom (vessel diameter 3 mm, intravascular attenuation 250 HU, extravascular density -70). Stents were imaged in axial orientation with standard parameters: 32 x 0.

Measurement of transcutaneous hemoglobin concentration by noninvasive white-light spectroscopy in infants.

Objective: To compare transcutaneously spectroscopically measured hemoglobin values with venous hemoglobin values in infants.

Study Design: Prospective study in healthy preterm and term infants who were breathing spontaneously.

Results: Recordings were obtained from 85 stable infants (median gestational age at measurement: 36 weeks [range: 34-43 weeks]; median body weight: 1890 g [range: 1095-4360 g]).

Comparison of 3D segmented gradient-echo and steady-state free precession coronary MRI sequences in patients with coronary artery disease.

Objective: Our objective was to compare two state-of-the-art coronary MRI (CMRI) sequences with regard to image quality and diagnostic accuracy for the detection of coronary artery disease (CAD).

Subjects And Methods: Twenty patients with known CAD were examined with a navigator-gated and corrected free-breathing 3D segmented gradient-echo (turbo field-echo) CMRI sequence and a steady-state free precession sequence (balanced turbo field-echo). CMRI was performed in a transverse plane for the left coronary artery and a double-oblique plane for the right coronary artery system.