Three-Dimensional Ultrasound

Abdominal three‐dimensional power Doppler imaging.

“…[3][4][5] There are 2 different types of scanning: mechanical and freehand. 6 In mechanical scanning a motor-driven assembly is used to move the transducer linearly across the skin, yielding a set of parallel 2D images.…”

“…6 In mechanical scanning a motor-driven assembly is used to move the transducer linearly across the skin, yielding a set of parallel 2D images. In freehand scanning there are 3 main ultrasonic transducer-locating systems under evaluation: acoustic and electromagnetic positioning devices, which are attached to the ultrasonic transducer to record the position and orientation of each 2D image needed for the 3D reconstruction, 4,7,8 and an image registration technique without any positioning device. With acoustic positioners, 3 sound-emitting devices are positioned on the transducer, and the emitted sound is detected by microphones located in predetermined positions around the patient.…”

“…The orientation of the transducer is determined by measuring the time of flight of each sound pulse to each microphone. 4 The electromagnetic positioner contains a spatially varying magnetic field transmitter placed near the patient and a receiver containing 3 orthogonal coils to measure the field strength, which is positioned on the transducer. It determines the location and position of the transducer by measuring the field strength.…”

“…It determines the location and position of the transducer by measuring the field strength. 4 A newer technique, which can be performed with the equipment used in the present study, is to measure the probe motion by using an image registration technique that does not require any additional position sensor. The probe motion can be found by matching similar image features in successive frames.…”

“…Three-dimensional (3D) ultrasonic angiography is a new power Doppler ultrasonographic imaging mode that appears to improve the visualization of vascular anatomy in abdominal sonography. [3][4][5] The aim of this study was to illustrate the utility of 3D ultrasonic angiography in the abdomen.…”