Intraoperative vector flow imaging of the heart

Abstract

Abstract-The cardiac flow is complex and multidirectional, and difficult to measure with conventional Doppler ultrasound (US) methods due to the one-dimensional and angle-dependent velocity estimation. The vector velocity method Transverse Oscillation (TO) has been proposed as a solution to this. TO is implemented on a conventional US scanner (Pro Focus 2202 UltraView, BK Medical) using a linear transducer (8670, BK Medical) and can provide real-time, angle-independent vector velocity estimates of the cardiac blood flow. During cardiac surgery, epicardiac US examinations using TO were performed on three patients. Antegrade central jet and retrograde flow near the vessel wall in the ascending aorta and the pulmonary artery were seen during systole, while stable vortices were seen in the aortic sinuses and complex flow patterns were seen around the valves during diastole. In the right atrium, a stable vortex was seen during the entire heart cycle. For comparison, simultaneous measurements were obtained with conventional spectral Doppler (SD) and intravenous catheter thermodilution technique (TD). Peak systolic velocities were underestimated by 18% compared to SD and cardiac output was underestimated by 16% compared to TD. This is the first time TO measurements have been obtained of cardiac flow. TO can potentially reveal new information of cardiovascular physiology and blood flow dynamics, and become a valuable tool in cardiology.

First report on intraoperative vector flow imaging of the heart among patients with healthy and diseased aortic valves

“…Other groups have previously published papers concerning angle-independent US estimations of the cardiovascular system [32,33] and we have previously published results concerning cardiac intraoperative exams on patients with healthy aortic valves [26,34]. However, to the authors' knowledge this is the first paper presenting in vivo results of real-time, quantitative US vector flow estimation among patients with healthy and diseased aortic valves.…”

Two-Step Rigid and Non-Rigid Image Registration for the Alignment of Three-Dimensional Echocardiography Sequences From Multiple Views

“…It is considered one of the safest modalities due to its lack of ionizing radiation, which does not expose patients to radiation, as well as being portable and less expensive compared to other modalities, allowing it to be used in various fields of medicine [3]. It is often used to acquire images of the human heart, brain, liver, and other organs [4], [5], [6] and is increasingly being used in animal studies [3]. Since ultrasound imaging is used to acquire images of different organs of the human body, over the years many registration algorithms have been developed to address monomodal ultrasound-to-ultrasound registration.…”