This is known as extended field-of-view or EFOV. This new technology allows manual movement of the probe along the direction of the array of the transducer, thus facilitating panoramic images without any loss in resolution. The technology causes estimation of translation and rotation of the probe by comparing images which are successive during the movement of the probe (Kim et al, 2003). The technology also has a mechanism for no probe-position sensing. the images in this technology are transformed geometrically based on the position and motion of the probe and then entered into the EFOV image buffer. They are then combined with images which are obtained previously to produce EFOV image. Through this technology, it is possible to acquire and record panoramic images of length as much as 60 cm, thus providing opportunity to view anatomical structures of various topography This allows displaying of larger pathologic structures or organs in a single image itself, along with their surroundings. Thus EFOV technology has many clinical applications. Infact, many studies have reported the usefulness of this technology in imaging superficial small parts (Kim et al, 2003). Weng and colleagues were the first researchers to introduce extended field-of-view technology, in 1997. They widely applied this technology to many field of sonography (Kim et al, 2003). According to Cooperberg et al (2001), "through the magic of computer technology, extended field of view imaging is back! Extended field of view images can now be created very easily and conveniently, in real time. The convenience and accuracy of real-time imaging is maintained while important anatomical perspectives are added."
In a pioneer study by Weng et al (1997), the researchers observed the benefits of extened field imaging that "combines the convenience of a real-time scanner with the spatial advantages of a static B-mode scanner and provides a panoramic image in real time