Santa Monica UCLA Medical Center

Cutting-edge Medical Imaging

By Joseph Lo

Images in OsiriX spanned across two 30-inch Apple Cinema Displays.

A bright green cursor dances across a 3D movie depicting a patient’s brain. Dr. Edward Zaragoza, associate clinical professor of radiological sciences at UCLA and clinical director in radiology at the Santa Monica UCLA Medical Center, uses his mouse to point out the location of disease in the computed tomography (CT) angiography study. This demonstration would be impressive enough if he were addressing a colleague sitting next to him. But Zaragoza is sitting in front of his Mac in his office while his audience observes the live demonstration on an iMac thousands of miles away — thanks to iChat AV and the medical imaging display application OsiriX.

Medical imaging is growing at an explosive pace, revolutionizing the way physicians peer inside the human body and allowing them to diagnose disease earlier, better, and faster. Instead of 2D x-ray films hanging on light boxes, today’s radiologists often view computer displays of 3D digital images, including those from CT, magnetic resonance imaging (MRI), and positron emission tomography (PET) scans. Using these 3D visualizations, radiologists can appreciate important information not otherwise apparent, such as the irregular shape or spiculated margin of a tumor or its precise spatial relationship to anatomic structures.

“The unique thing about OsiriX is that it gives users the ability to do advanced imaging manipulation outside the traditional radiology-centric environment.”

Adding to the sophistication of this field, 4D and 5D imaging has emerged in recent years. These images add dimensions of time (such as cardiac CT scanning so fast that it captures images of the beating heart) and functional data (such as PET/CT fusion, which combines a patient’s anatomical and functional images).

Meeting the Demand for Image-Display Technology

UCLA was a pioneer in the development of Picture Archiving Communication System (PACS) technology, which heralded the entry of radiology into the digital age by allowing the display, transmission, and storage of digital medical images. In addition, former UCLA radiologists Dr. Antoine Rosset and Dr. Osman Ratib were responsible for creating OsiriX, a free, open source program designed by radiologists for radiologists for multimodal and multidimensional visualization. Available only for the Mac, OsiriX takes advantage of the platform’s unique hardware and software strengths.

As a result, standard Apple notebook and desktop computers at UCLA have been transformed into full-fledged Digital Imaging and Communications in Medicine (DICOM) PACS workstations. Mac computers running OsiriX are not only fully compatible with commercial PACS workstations, which cost well into the five- or six-figure range, but also have the same industrial networking strength.

As a Universal application, OsiriX runs natively on both Intel-based and PowerPC-based Macs. It also uses multithreading to take advantage of the acceleration that multiple and dual-core processors offer. A Mac can therefore offer the performance and functionality of commercial PACS workstations costing ten or twenty times more.

Not surprisingly, OsiriX has more than 8000 users from such diverse fields as radiology, radiation oncology, nuclear medicine, medical physics, and biomedical research. OsiriX is popular, Zaragoza says, “not just for economics, but also for its intrinsic functionality and usability with a minimum of user training.”

3D Wherever You Are

Why is medical imaging one of the most challenging digital environments in science? Radiologists must perform complex analyses of vast amounts of data quickly and correctly. For example, CT and MRI systems can generate hundreds of images in one scan, producing files hundreds of megabytes in size. Radiologists must interpret all of this data in a short time and are responsible for diagnosing any one of hundreds of diseases for scores of patients everyday.

To address this challenge, top hospitals like UCLA are equipped with 3D workstations from a wide variety of commercial vendors, such as the Vitrea workstation from Vital Images. But doctors like Edward Zaragoza often find themselves working in locations — such as their homes or their offices — where 3D functionality isn’t available. In such situations, Zaragosa uses OsiriX on his PowerBook to pull the patient data off the PACS network and visualize it in 3D to help him finish reading a case.

“I don’t have a Vitrea workstation at home, and neither do my orthopedic surgeons,” says Zaragoza with a laugh. “The unique thing about OsiriX is that it gives users the ability to do advanced imaging manipulation outside the traditional radiology-centric environment.”

For example, he relates: “I was on call last night. My resident contacted me at home to review a CT scan performed to rule out appendicitis. In just a few minutes, he transferred the study to my home system — a Power Mac G5 Quad computer. I was able to view the study and perform multi-planar axial/sagittal/coronal reformations in real time, all on my home computer!”

1 2 Next Page >