O-MODE ULTRASOUND

O-mode ultrasound reduces artifacts

By Kate Madden Yee, AuntMinnie.com staff writer

November 6, 2014 --

Sunday, November 30 | 12:05 p.m.-12:15 p.m. | SSA21-09 | Room S405AB

In this Sunday presentation, researchers will discuss how O-mode ultrasound is a promising technique for reducing artifacts typical with B-mode imaging.

Conventional ultrasound is limited by the need for beamforming, according to presenter Dr. Richard Barr, PhD, of Northeastern Ohio Medical University, and colleagues. O-mode ultrasound does not require a beamformer, offers constant lateral resolution, and decreases the shadowing that can arise from small pockets of gas. Barr's team conducted a pilot study to evaluate the use of O-mode imaging in a clinical setting.

The study included 10 patients who each received a complete abdominal ultrasound exam on a conventional ultrasound scanner as well as an O-mode device. A group of experienced ultrasound radiologists compared the images, ranking them on depth of penetration, shadowing artifacts, and overall image quality.

For all 10 cases, O-mode ultrasound visualized deep structures as well as or better than conventional B-mode ultrasound, the researchers found. In addition, O-mode ultrasound was able to visualize areas shadowed by ribs or small pockets of gas that B-mode could not.

O-mode Ultrasound, A New Novel Technique

Richard Gary Barr MD, PhD (Presenter): Consultant, Siemens AG Consultant, Koninklijke Philips NV Research Grant, Siemens AG Research Grant, SuperSonic Imagine Speakers Bureau, Koninklijke Philips NV Research Grant, Bracco Group Speakers Bureau, Siemens AG Consultant, Toshiba Corporation Research Grant, Esaote SpA , Alex Lomes PhD : Stockholder, Orcasonix Ltd , Mati Shirizly PhD : Shareholder, Orcasonix Ltd.

PURPOSE
Conventional US limitations and artifacts are related to the need for beam forming. O-mode introduces a novel approach that does not require a beam former, provides constant lateral resolution independent on depth of penetration and significantly decreases the shadowing from small pockets of gas allowing for new imaging windows to be utilized. The Doppler effect is evoked artificially by transmitting US signal from a "moving" transducer. Such transmitting scheme creates echo with different RF frequency shifts coming from different scatterers, which are located at the same depth, but at different lateral positions. This method provides exact lateral localization by exchanging the traditional focusing procedure (along line-of-sight) to signal processing of frequency-modulated signals coming from each depth, maintaining constant lateral resolution and improved
shadowing performance. This is a pilot study to evaluate O-mode in a clinical setting.

METHOD AND MATERIALS
10 patients participated in an IRB approved, HIPPA compliant study to evaluate the possible potential advantages of the O-mode imaging. Patients received a complete abdominal exam on a conventional ultrasound system (Esaote, My Lab Twice, Genoa, IT; Philips IU22, Bothell, Wa, or Siemens S3000, Mountain View, Ca) in addition to the Orcasonix O-mode system. Comparison of the images was performed by visual inspection by a board certified Radiologists with 20 years experience in ultrasound imaging. Images were scored as to depth of penetration, shadowing artifacts, and overall acceptability of image quality.

RESULTS
In all 10 cases O-mode was able to visualize deep structures equally or better than conventional B-mode. In areas of shadowing from ribs or small pockets of gas O-mode was able to visualize structures deep to the bone or gas which were able to be visualized on B-mode.

CONCLUSION
Preliminary clinical validation of O-mode imaging is promising. Additional post processing is required to improve O-mode image quality. O-mode imaging has several advantages over B-mode imaging including increased deep visualization, marked decreased shadowing and refractive artifacts. Without the need for a beam former smaller lighter ultrasound systems are possible.

CLINICAL RELEVANCE/APPLICATION
O-mode imaging can improve ultrasound imaging by significantly decreasing artifacts seen in B-mode imaging. The lack of a beam former allows for smaller ultrasound systems.