Biomedical subjects

Onno Wink

Publications and source records attributed to Onno Wink.

5 recordsLinked to original sources

PubMed2004

Randomized study of the safety and clinical utility of rotational angiography versus standard angiography in the diagnosis of coronary artery disease.

This study evaluates the safety and clinical utility of rotational angiography in the diagnosis of coronary artery disease. High-speed rotational angiography is a newly available angiographic modality that gives a dynamic multiple-angle perspective of the coronary tree during a single contrast injection. We prospectively randomized 56 patients referred for diagnostic coronary angiography to either standard or rotational angiography. Contrast and radiation utilization were compared between the two groups. The number of additional cine acquisitions needed was used to determine adequacy of the diagnostic study protocol. Rotational angiography was successfully completed in all subjects. There was a 33% reduction in contrast utilization in the rotational group as compared to the standard group (35.6 +/- 12.6 vs. 52.8 +/- 10.7 ml, respectively; P < 0.0001). Additionally, there was a 28% reduction in total radiation exposure in the rotational group as compared to the standard group (39.0 +/- 18.5 vs. 53.9 +/- 23.4 Gycm(2), respectively; P = 0.01). Total whole-body radiation exposure to the primary operator was 144 mrem with rotational angiography and 170 mrem with standard angiography. Procedure time tended to be shorter for rotational angiography (353.9 +/- 146.7 vs. 396.8 +/- 165.8 s; P = 0.3). Rotational coronary angiography can be rapidly performed in any patient and provides a significant reduction in contrast and radiation utilization while at the same time providing adequate angiographic data to complement or replace standard coronary angiography in the evaluation of coronary artery disease.

Adult↗

PubMed2004

Multiscale vessel tracking.

A method is presented that uses a vectorial multiscale feature image for wave front propagation between two or more user defined points to retrieve the central axis of tubular objects in digital images. Its implicit scale selection mechanism makes the method more robust to overlap and to the presence of adjacent structures than conventional techniques that propagate a wave front over a scalar image representing the maximum of a range of filters. The method is shown to retain its potential to cope with severe stenoses or imaging artifacts and objects with varying widths in simulated and actual two-dimensional angiographic images.

Algorithms↗

PubMed2003

Intra-procedural coronary intervention planning using hybrid 3-dimensional reconstruction techniques.

RATIONALE AND OBJECTIVES: The purpose of this study was to develop a method to assist the cardiologist in planning an interventional procedure while the patient is on the catheterization table. MATERIALS AND METHODS: A rotational single plane x-ray system is used to acquire images while rapidly rotating the C-arm around the patient. Based on electrocardiogram-selected projections, both a volumetric cone-beam reconstruction of the coronary tree as well as a three-dimensional model of the vessel segment of interest is generated. This information is used to compute the appropriateness of a range of different viewing angles with respect to the overlap and foreshortening of the vessel segment of interest during the cardiac cycle which results in an interactive optimal view map. RESULTS: The proposed method has been tested on patient data and several phantom objects. The results show that both an accurate 3D model of a vessel segment of interest and its associated optimal view map can be generated to predict an appropriate gantry angle for subsequent image acquisition. CONCLUSION: The method provides an appropriate and feasible tool to assist interventional cardiologists in planning a coronary intervention while the patient is still on the catheterization table following diagnostic coronary angiography.

Cardiac Catheterization↗

PubMed2003

Blood pool contrast-enhanced MRA: improved arterial visualization in the steady state.

Blood pool agents (BPAs) for contrast-enhanced magnetic resonance angiography (CE-MRA) allow prolonged imaging during the steady state when the agent is distributed through the complete vascular system. This increases both the spatial resolution and the contrast resolution. However, simultaneous venous and arterial enhancement hampers interpretation. For the pelvic region of the vasculature, it is shown that arterial visualization in this equilibrium phase can be improved if the central arterial axis (CAA) is known. However, manually obtaining this axis is not feasible in clinical practice. Therefore, a method is presented that utilizes images acquired during the first pass of the contrast agent to find the CAA in the steady-state data with minimum user initialization. The accuracy of the resulting CAA is compared with tracings of three observers in six patient datasets. It was found that the mean difference between the semiautomatic method and the manual delineation is 1.32 mm in the steady-state data, and that the resulting CAA was always within the arterial lumen, which is an important prerequisite for both improved visualization and segmentation.

Algorithms↗

PubMed2002

3D MRA coronary axis determination using a minimum cost path approach.

A method is introduced to automatically find the coronary axis based on two or more user-defined points, even in the presence of a severe stenosis. The coronary axis is determined by finding a minimum cost path (MCP) in a feature image in which the tubular-like structures are enhanced. The results of the proposed method were compared with manually drawn central axes to estimate the accuracy. In 32 3D TFE-EPI acquisitions of patients and volunteers, 14 right coronary arteries (RCAs), 15 left anterior descending arteries (LADs), and eight left circumflex arteries (LCXs) were manually tracked twice by two operators to determine a reference axis and to assess the inter- and intra-user variability. On average, the maximum distance to the reference axis, based on only two user-defined points, is less than 1.5 mm; the average distance is around 0.65 mm, which is less than the average in-plane resolution. The results of the method are comparable to those of the manual operators.

Coronary Stenosis↗