CECS Spotlight: Operation vision

New technology could help surgeons see inside patients with much greater accuracy.

The results of the PhD candidate's research on combining of medical images and real-time simulation of ultrasound have already been published in the highest ranking computer-vision and medical-imaging conferences. To top it off, the work has also earned Shams a 2008 Fulbright Postgraduate Scholarship, which he will use to attend one of the best medical imaging groups in the US at Harvard University and Brigham and Women's Hospital.

Shams, from the ANU College of Engineering and Computer Science, is hoping to develop an intelligent scanner that uses new image processing technology to create an unparalleled three-dimensional real-time view, making surgery patients virtually see-through.

High quality 3D medical imaging technologies such as magnetic resonance imaging (MRI) and computed tomography (CT) are typically used inter-operatively for surgical planning. Imaging technologies that are available during operations have a more limited field of view and image quality.

Shams hopes to combine images taken before surgery with images used during the procedure to give surgeons a clearer representation of the organ they're working on.

"Registration is a problem frequently encountered in medical-image analysis," Shams says. "It's often required to align images acquired by different imaging devices and techniques. Images obtained by various medical imaging techniques - multi-modal images - often depict information of complementary nature. For example, CT scans are useful for depicting hard structures such as bones and calcifications within the subject, while MRI is best suited for evaluating soft tissue.

"In clinical applications, it's essential to combine useful data from different image modalities to assist in diagnosis, treatment planning, evaluation of surgical and therapeutical procedures and for image guided surgery."

Shams' research focuses on registration of multi-modal images particularly in real-time and intra-operatively and real-time simulation of ultrasound.

"Ultrasound is an incredibly flexible imaging technique. It's virtually harmless, has a high temporal resolution (meaning that it allows viewing streams of images in real-time) and is less expensive than other imaging techniques such as MRI and CT. Ultrasound devices are low-profile and portable and there is a myriad of ultrasound probes from intra-vascular and endoscopic probes to hand-held external probes for 2D and 3D imaging. This makes ultrasound the imaging method of choice for intra-operative applications, such as laparoscopic surgery, to provide the surgeon with a more global view of the anatomy.

"The difficulty here is that navigating a laparoscopic probe requires extensive training for optimal use and without a frame of reference ultrasound images are difficult to interpret. This is where registration and simulation of ultrasound is useful. Ultrasound simulation can be used for training without the need for an actual patient. It can also be used for registration of laparoscopic ultrasound images with previously acquired MR or CT images to improve the confidence of the operator by placing the ultrasound plane within a higher quality 3D image. One can also improve the quality of real-time imaging by combining the higher quality CT and MR images with real-time ultrasound.

"Ultimately, the goal is to improve the visibility of the area and provide surgeons with high-quality images that increase the number of laparoscopic surgeries that will be done in the future," he adds.