Three-dimensional Ultrasound Data Research Articles

Dynamic three-dimensional freehand echocardiography using raw digital ultrasound data

In this paper, we present a new method for simple acquisition of dynamic three-dimensional (3-D) ultrasound data. We used a magnetic position sensor device attached to the ultrasound probe for spatial location of the probe, which was slowly tilted in the transthoracic scanning position. The 3-D data were recorded in 10–20 s, and the analysis was performed on an external PC within 2 min after transferring the raw digital ultrasound data directly from the scanner. The spatial and temporal resolutions of the reconstruction were evaluated, and were superior to video-based 3-D systems. Examples of volume reconstructions with better than 7 ms temporal resolution are given. The raw data with Doppler measurements were used to reconstruct both blood and tissue velocity volumes. The velocity estimates were available for optimal visualization and for quantitative analysis. The freehand data reconstruction accuracy was tested by volume estimation of balloon phantoms, giving high correlation with true volumes. Results show in vivo 3-D reconstruction and visualization of mitral and aortic valve morphology and blood flow, and myocardial tissue velocity. We conclude that it was possible to construct multimodality 3-D data in a limited region of the human heart within one respiration cycle, with reconstruction errors smaller than the resolution of the original ultrasound beam, and with a temporal resolution of up to 150 frames per second.

Three-dimensional endoscopic ultrasound of the esophagus. Preliminary experience.

The aim of this study was to develop a technique for three-dimensional endoscopic ultrasound of the esophagus based on standard ultrasonic images. Endoscopic ultrasound was performed in five esophageal cancer patients using a high-resolution miniprobe (360 degrees, 12.5 MHz). For acquisition of three-dimensional data sets, the miniprobe was attached to a stepping motor that enabled ECG-triggered withdrawal of the transducer. Three-dimensional images were reconstructed from serial transverse sections on a PC-based 3D work station. Twelve volume scans were obtained in five patients with esophageal cancer. The system enabled the acquisition of accurate three-dimensional ultrasound data within 30-50 s. Computed image processing allowed us to display the data in transverse, longitudinal, and oblique sections, or as a 3D reconstruction. Three-dimensional imaging provided accurate visualization of the tumor and surrounding structures in all cases. The tumor stage was determined correctly in four of five patients. Longitudinal scan planes and 3D views improved the assessment of longitudinal tumor infiltration and the spatial relation of the tumor to relevant mediastinal structures. This study shows that three-dimensional endoscopic ultrasound of the esophagus is technically feasible. The technique allows the assessment of local tumor spread in previously unattainable scan planes and 3D views. This promising preliminary experience should encourage further exploration of this method.

Visualization of 3D ultrasound data

It is suggested that ultrasound data acquisition will play an increasing role in the future of medical imaging. Unlike magnetic resonance imaging (MRI) and computerized tomography (CT), ultrasound offers interactive visualization of underlying anatomy in real time. Additionally, ultrasound equipment costs far less and does not use ionizing radiation or require specialized facilities. The different methods for multidimensional medical imaging and scientific visualization are reviewed. Several volume visualization algorithms are discussed. They are multiplexer slicing, surface fitting, volume rendering, data classification, and viewing and shading. Three-dimensional ultrasound data display methods are also discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>