A Clearer Picture of the Heart?
Date: May 15, 2010
Hopkins-led study puts CT perfusion imaging to the test.
At bottom, says cardiologist Rich George, the mission of a new study led by Johns Hopkins is simple: Which technique is best when it comes to gauging blood flow in a suspect heart?
For five years now, George has collaborated with senior cardiologist João Lima in refining the imaging quality provided by the world’s most vivid CT scanning technology, known as the 320 detector-row CT. During that time, George says, the group’s tinkering has borne fruit.
When the 320 was installed here in 2007, it was the most powerful scanner in North America. Clinicians marveled at its vivid three-dimensional studies of the heart, but they became even more impressed after George and others devised protocols and software for the 320 that could accurately measure the speed of blood flowing through the heart’s arteries.
They soon learned the enhancements could shed light on a longstanding dilemma in cardiology: Various diagnostic techniques could detect vascular blockages or reductions of blood flow within the heart, but no diagnostic test was able to provide both pieces of information simultaneously in a noninvasive fashion.
Traditional stress testing with imaging could detect blockages indirectly through the so-called SPECT technique. Explorations with a catheter could confirm their presence, map them out in greater detail and then be further deployed in angioplasty procedures. But the Hopkins group found that the 320 could more accurately determine when a blockage impedes the process of perfusion. They also learned it could find the answer in less time and with less exposure to radiation than other techniques.
Now the group needs to see if their convictions hold up to scientific rigor. “We want to prove,” says George, “that a noninvasive test is as good as a SPECT study and a catheterization combined.”
Toward that end, in January Hopkins unveiled the launch of a one-year international study in collaboration with cardiac imaging specialists at 15 institutions in eight countries. They plan to enroll 400 patients before reaching conclusions.
If the hypothesis holds, says George, many of the 1.3 million U.S. patients who normally receive cardiac catheterizations each year might learn their diagnoses with a simple, 25-minute scan by the 320 CT, saving both money and time.
For study info, call 410-614-3192