AMA Conference Backgrounder: 3-D Images of Brain, Lung Create Virtual Body-Scape
DURHAM, N.C. -– Doctors at Duke University Medical Center are taking a guided tour inside the human body without ever wielding a scalpel. By combining the latest computer technology and medical imaging devices to create three-dimensional "bodyscapes," they are simultaneously enhancing their ability to diagnose disease and reducing the number of invasive procedures patients must undergo. Radiologists Linda Gray and Page McAdams are pioneers in a futuristic approach to diagnosing life-threatening disorders such as intracranial aneurysms, which cause severe bleeding in the brain cavity, and lung cancer. The doctors first use computerized tomography (CT) to take a series of X-ray-like images of an organ. Then they use a computer to reassemble the individual two-dimensional images into a three-dimensional virtual bodyscape that they can fly through and examine from many different perspectives.
"The 3D CT scan allows a radiologist to see the delicate blood vessels in greater detail than is available by any other technology," Gray said. "When a patient is bleeding in the brain, time is of the essence. Using this technology, a surgeon can see the problem quickly and know what to expect when during surgery."
In most hospitals suspected aneurysms are diagnosed by snaking a thin, flexible tube through a blood vessel in the leg up to the vessels at the base of the brain. They then inject a type of dye through the tube and take X-ray images of the vessels. This procedure, called angiography, allows doctors to see the vessels, but is invasive and takes one to three hours to complete.
The 3D CT scan, by contrast, takes about a minute to complete and costs less than half the price of the angiography. Gray has perfected the technique to the point that doctors are using it on a routine basis at Duke Hospital.
"We are significantly shortening the time from the emergency room to the operating room," Gray says. "Those minutes saved can sometimes mean the difference between life and death."
Similarly, McAdams has used the same technique to create a virtual roadmap through the lung's airways. Doctors use the images to locate the best place in the lung tissue to place a fine needle necessary to take a sample of lung or lymph node tissue. Tissue sampling, called biopsy, is used to diagnose cancer.
In routine biopsy, doctors snake a thin, fiberoptic tube from the mouth, down the esophagus and finally into the lung, to see the bronchial passages. The procedure is routine, but invasive and uncomfortable for the patient. Using CT scanning, doctors take non-invasive images of the lungs and use the computer to reconstruct the airways in three dimensions. In a preliminary study of 17 patients, doctors used the 3D images to guide their subsequent biopsy procedure. They found the technique was at least as sensitive, and in some cases, more sensitive, in helping them locate a malignancy in the lung as the traditional approach.