May 5, 2016
A sampling of 3-D imaging. Type A with mediastinal hemorrhage.
Computed tomography has undergone a revolution over the past few decades, morphing from scans that produce several hundred slices to those capable of producing several thousand. However, says Johns Hopkins radiologist Elliot Fishman, what this modality can’t do is put this information together for surgeons in a way that shows them exactly what it looks like inside a patient—information that’s pivotal for tracking disease progression, planning for a procedure or following a patient’s progress after treatment.
“In radiology, we like to think we’re in the business of providing information. But is it useful information?” Fishman, who directs diagnostic imaging and body CT at The Johns Hopkins Hospital, asks. “Whether it’s a coarctation or an aneurysm, problems with the aorta are threedimensional. This vessel is not a single slice or a series of slices.”
To address this need, Fishman and his colleagues began developing 3-D CT nearly three decades ago. The team launched its work with Pixar, using hardware that the animation company developed to turn flat medical images into three dimensions. Over the years, these physicians and researchers have helped to fine-tune the software, making it not only faster—bringing the time it takes to reconstruct images from slices into three dimensions from more than a day to slightly more than a second—but also portable. Now physicians have the ability to pull up 3-D images anywhere on their phones or tablets.
While 3-D imaging is valuable in many areas of medicine, it’s particularly advantageous for the spectrum of aortic diseases. For example, Fishman says, 3-D CT has become pivotal for evaluating coarctations: the type, extent of narrowing and which procedure might work best to repair this defect. Similarly, for diseases that affect the aorta, such as Marfan syndrome or Loeys-Dietz syndrome, being able to view the problem in 3-D can help answer a bevy of questions, ranging from the extent of root involvement to how ectatic a patient’s blood vessels have become.
A sampling of 3-D imaging. Left, type B with aneursym of thoracic aorta; slow flow in the false lumen.
Providing this material in three dimensions isn’t just easier for surgeons to work with, Fishman explains. It’s also more accurate. Studies comparing 3-D CT with flat CT slices have shown that 3-D images provide measurements that are between 20 to 30 percent more accurate—a difference that could be pivotal for medical decision-making.
Having a 3-D imaging modality also makes it easier to communicate with patients, Fishman adds, providing doctors the ability to bring videos of a patient’s own images to the bedside to explain what’s happening and to plan for the future.
Unlike many centers that use this technology, Johns Hopkins is able to provide 3-D CT scans 24/7. Scans can be done either on an urgent basis for patients coming in from the Emergency Department or for outpatients, Fishman says, with information customizable for referring physicians’ specific needs. He and his team are currently working to make this information even more accessible by providing it in a virtual meeting environment, where he and other Johns Hopkins radiologists can discuss images and findings with referring physicians.
“We always want to make sure that we’re doing the absolute best thing we can for every patient,” Fishman says. “And each time technology advances, we’re able to give our patients more and more.”
View more of Fishman’s images at ctisus.com.