R.J. Van Geuns

Bio: R.J. Van Geuns is an academic researcher from Erasmus University Rotterdam. The author has contributed to research in topics: Coronary arteries & Coronary artery disease. The author has an hindex of 17, co-authored 46 publications receiving 1206 citations. Previous affiliations of R.J. Van Geuns include National Institutes of Health.

Breath-hold coronary MR angiography with volume-targeted imaging.

Abstract: PURPOSE: To illustrate a new concept for fast coronary artery screening with breath-hold volume targeted magnetic resonance (MR) imaging. MATERIALS AND METHODS: Ten volunteers and 25 patients were imaged at a field strength of 1.5 T with an MR system with phased-array-coil reception and capable of echo-planar imaging. End-expiration breath-hold volume localization of the entire heart was performed with three-dimensional (3D) multishot segmented echo-planar imaging in 16-22 heartbeats. Interaction with a multiplaner reformation platform provided the optimal double-oblique volumes necessary to target seven coronary artery segments. Each segment was evaluated with 24-mm-thick volumes and breath holds at end expiration and magnetization transfer-enhanced 3D turbo fast low-angle shot imaging in 21 heartbeats. An intravascular contrast agent was used in eight patients to improve blood-myocardium contrast for the heart volume localizer acquisitions. RESULTS: The entire coronary tree was consistently covered in f...

Optical coherence tomography assessment of the acute effects of stent implantation on the vessel wall: a systematic quantitative approach

Abstract: Objective: To observe and characterise vessel injury after stenting using optical coherence tomography (OCT), to propose a systematic OCT classification for periprocedural vessel trauma, to evaluate its frequency in stable versus unstable patients and to assess its clinical impact during the hospitalisation period. Setting: Stenting causes vessel injury. Design and interventions: All consecutive patients in whom OCT was performed after stent implantation were included in the study. Qualitative and quantitative assessment of tissue prolapse, intra-stent dissection and edge dissection were performed. Results: Seventy-three patients (80 vessels) were analysed. Tissue prolapse within the stented segment was visible in 78/80 vessels (97.5%). Median number of tissue prolapse sites was 8 (IQR 4-19), mean (SD) area 1.04 (0.9) mm2. Intra-stent dissection flaps were visible in 69/80 vessels (86.3%) (median number 3 (IQR 1.25-6), maximum flap length 450 (220) μm). Fifty-five out of 80 vessels (68.8%) showed dissection cavities (median number 2 (IQR 0-4.75), maximum depth 340 (170) μm). Edge dissection was visible in 20 vessels (mean (SD) length flap 744 (439) μm). The frequency of tissue prolapse or intra-stent dissection was similar in stable and unstable patients (95.6% vs 100%, p = 0.5 for tissue prolapse; 91.1% vs 82.9%, p = 0.3 for intra-stent dissection). There were no events during the hospitalisation period. Conclusions: OCT allows a detailed visualisation of vessel injury after stent implantation and enables a systematic classification and quantification in vivo. In this study, frequency of tissue prolapse or intra-stent dissections after stenting was high, irrespective of the clinical presentation of the patients, and was not associated with clinical events during hospitalisation.

Intravenous coronary angiography by electron beam computed tomography: a clinical evaluation

Abstract: Background—Noninvasive detection of coronary stenoses with electron beam CT (EBCT) after intravenous injection of contrast medium has recently emerged. We sought to determine the diagnostic accuracy of EBCT angiography in the clinical setting using conventional coronary angiography as the “gold standard.” Methods and Results—Thirty-seven patients (30 men) were investigated. After intravenous injection of 150 mL of contrast medium, 40 to 60 consecutive transaxial tomograms, covering the proximal and middle parts of the coronary arteries, were obtained with ECG triggering at end diastole during breath-holding. Three-dimensional reconstructions of the proximal and middle parts of the arteries were compared with the conventional angiograms. Of the 259 proximal and middle coronary segments, 211 (81%) were analyzable by EBCT. Of the left anterior descending coronary artery (LAD) segments, 95% were assessable. Right coronary artery (RCA) and left circumflex artery (LCx) segments were assessable in 66% and 76%, respectively. Overall sensitivity and specificity to detect a .50% diameter stenosis were 77% and 94%, respectively. This was 82% and 92% for the LAD, 60% and 97% for the RCA, and 83% and 89% for the LCx (all figures based on assessable lesions). Conclusions—Intravenous EBCT coronary angiography is a promising coronary imaging technique. The technique is not yet robust enough to be an alternative to conventional coronary angiography. It can detect and rule out significant coronary artery disease of the left main proximal and mid portions of the LAD with good accuracy. (Circulation. 1998;98:2509-2512.)

Magnetic resonance imaging of the coronary arteries: clinical results from three dimensional evaluation of a respiratory gated technique

Abstract: BACKGROUND: Magnetic resonance coronary angiography is challenging because of the motion of the vessels during cardiac contraction and respiration. Additional challenges are the small calibre of the arteries and their complex three dimensional course. Respiratory gating, turboflash acquisition, and volume rendering techniques may meet the necessary requirements for appropriate visualisation. OBJECTIVE: To determine the diagnostic accuracy of respiratory gated magnetic resonance imaging (MRI) for the detection of significant coronary artery stenoses evaluated with three dimensional postprocessing software. METHODS: 32 patients referred for elective coronary angiography were studied with a retrospective respiratory gated three dimensional gradient echo MRI technique. Resolution was 1.9 x 1.25 x 2 mm. After manual segmentation three dimensional evaluation was performed with a volume rendering technique. RESULTS: Overall 74% (range 50% to 90%) of the proximal and mid coronary artery segments were visualised with an image quality suitable for further analysis. Sensitivity and specificity for the detection of significant stenoses were 50% and 91%, respectively. CONCLUSIONS: Volume rendering of respiratory gated MRI techniques allows adequate visualisation of the coronary arteries in patients with a regular breathing pattern. Significant lesions in the major coronary artery branches can be identified with a moderate sensitivity and a high specificity.

Assessment of coronary artery disease by cardiac computed tomography : A scientific statement from the american heart association committee on cardiovascular imaging and intervention, council on cardiovascular radiology and intervention, and committee on cardiac imaging, council on clinical cardiology

Abstract: This scientific statement reviews the scientific data for cardiac computed tomography (CT) related to imaging of coronary artery disease (CAD) and atherosclerosis. Cardiac CT is a CT imaging technique that accounts for cardiac motion, typically through the use of ECG gating. The utility and limitations of generations of cardiac CT systems are reviewed in this statement with emphasis on CT measurement of CAD and coronary artery calcified plaque (CACP) and noncalcified plaque. Successive generations of CT technology have been applied to cardiac imaging beginning in the early 1980s with conventional CT, electron beam CT (EBCT) in 1987, and multidetector CT (MDCT) in 1999. Compared with other imaging modalities, cardiac CT has undergone an accelerated …

Coronary Magnetic Resonance Angiography for the Detection of Coronary Stenoses

Abstract: Background An accurate, noninvasive technique for the diagnosis of coronary disease would be an important advance. We investigated the accuracy of coronary magnetic resonance angiography among patients with suspected coronary disease in a prospective, multicenter study. Methods Coronary magnetic resonance angiography was performed during free breathing in 109 patients before elective x-ray coronary angiography, and the results of the two diagnostic procedures were compared. Results A total of 636 of 759 proximal and middle segments of coronary arteries (84 percent) were interpretable on magnetic resonance angiography. In these segments, 78 (83 percent) of 94 clinically significant lesions (those with a ≥50 percent reduction in diameter on x-ray angiography) were also detected by magnetic resonance angiography. Overall, coronary magnetic resonance angiography had an accuracy of 72 percent (95 percent confidence interval, 63 to 81 percent) in diagnosing coronary artery disease. The sensitivity, specificity,...

Clinical indications for cardiovascular magnetic resonance (CMR): Consensus Panel report.

Abstract: This paper was guest edited by Dr. E. Fleck. Deutsches Herzzentrum Berlin, Germany Cardiovascular magnetic resonance (CMR) is established in clinical practice for the diagnosis and management of diseases of the cardiovascular system. However, current guidelines for when this technique should be employed in clinical practice have not been revised since a Task Force report of 1998.1 Considerable technical and practice advances have been made in the intervening years and the level of interest from clinicians in this field is at an unprecedented level. Therefore the aim of this report from a Consensus Panel of established experts in the field of CMR is to update these guidelines. As CMR is a multi-disciplinary technique with international interest, the Consensus Panel was composed of European and American cardiologists and radiologists with major input from members with additional established expertise in paediatric cardiology, nuclear cardiology, magnetic resonance physics and spectroscopy, as well as health economics. The Consensus Panel was originated, approved and funded in its activities by the Working Group on CMR of the European Society of Cardiology and the Society for Cardiovascular Magnetic Resonance. The Consensus Panel recommendations are based on evidence compiled from the literature and expert experience. If there is insufficient evidence in the literature, this is indicated in the report but usually no recommendations are made under these circumstances. The appropriateness of using CMR is described for the frequent disease entities where imaging information may be warranted. The diagnostic use of CMR will be described in the context of other, competing imaging techniques, with particular emphasis on the differential indications with respect to echocardiography. The usefulness of CMR in specific diseases is summarized by means of the following classification: