Health Imaging & IT - March 2008 - (Page 21)

“The scanner has changed cardiac imaging and patient care,” says John Lesser, MD, director of clinical cardiology. “Cardiologists are doing fewer normal invasive catheterizations.” That’s because physicians are ordering cardiac CT rather than an invasive cardiac catheterization when a patient has an equivocal stress test. If the CT is normal, the patient can bypass the cath lab. Cardiac CT also is the test of choice for cardiac patients who can’t tolerate the exercise required for a stress test. other sites, like Lenox Hill Heart and Vascular Institute in New York City, turn to CT as a cardiac and vascular imaging workhorse. The real question, says Harvey Hecht, MD, director of cardiovascular CT, is not which applications are appropriate for Philips Healthcare Brilliance 64-slice CT, but which aren’t. Cardiovascular CT data provides crucial information, helping physicians determine if a patient’s symptoms are related to coronary artery blockage and to calculate the degree of blockage. Cardiovascular CT also provides information about plaque, so cardiologists can decide the optimal course to prevent rupture. “We use the scanner for a whole range of services. It’s the first test used to evaluate cardiac patients. A cardiac CT scan is superior to a traditional stress test for determining the appropriate therapy: angiography, stenting or bypass surgery. We also use the scanner to evaluate patients with equivocal stress tests and after cardiac catheterization to answer unresolved questions,” says Hecht. For example, the institute uses cardiac CT to evaluate coronaries not adequately visualized during cardiac catheterization because of damping of the catheter or inability to cannulate the artery. CT images also help physicians determine the course of anomalous vessels and delineate the occluded segment of a chronic total occlusion. Finally, physicians use CT images to size stents. The reason behind the effectiveness of cardiovascular CT over conventional studies is quite simple. “Cardiac CT provides a 3D view of the coronary arteries. We can rotate the arteries on the post-processing workstation. Images acquired in the cath lab are more limited,” says Hecht. In fact, Hecht and his colleagues found that CT provides a truer picture than invasive coronary artery angiography, showing healthy arteries or mild disease more clearly than the invasive study. Intravascular ultrasound (IVuS) confirms CT results in 85 percent of patients, says Hecht. Cardiac CT also is proving useful in evaluating patients who present to the er with chest pain. Abbott Northwestern Hospital is part of a multi-center trial comparing cardiac CT and nuclear stress testing. “Preliminary data indicate that CT is a good option from the cost, safety and accuracy perspectives,” says Lesser. HealthImaging.com the next generation…now the next leap forward in cardiac imaging is higher slice ct scanners like toshiba america Medical systems aquilionOne. the 320-slice system represents the ct workhorse of the future, says João a.c. lima, Md, director of cardiovascular imaging at Johns Hopkins Hospital in Baltimore. Md. since the hospital deployed aquilionOne in October 2007, the system has become its exclusive cardiac ct imaging solution. aquilionOne improves on 64-slice ct in a number of ways, says lima. coverage spans 16 centimeters to cover the entire heart in one rotation and eliminate the need for helical mode. instead, aquilionOne uses simultaneous acquisition mode; the patient does not move as the gantry rotates, bypassing the need for helical reconstruction, which can result in misalignment during the reconstruction process. the hospital uses prospective gating on most patients; all slices are obtained at the same time, which translates into greater accuracy. finally, aquilionOne’s radiation dose of 3 to 5 millisieverts (msv) is one-fourth to one-third of the dose of firstgeneration 64-slice scanners. “the main paradigm shift with the new system is the ability to obtain perfusion studies in combination with angiographic data,” explains lima, who predicts that the future workup of patients with suspected coronary disease will begin with a ct angiogram and calcium scoring. this first step should answer questions for about three-fourths of patients, says lima. the remaining patients will require perfusion stress testing with adenosine. “ct imaging will be tailored to each patient’s clinical condition,” continues lima. for example, if a patient suffered a previous infarction, the scan can measure the size of the infarct. [ Whole heart CTA acquired with a dose of 4-5 cardiac ct imaging mSV on Toshiba’s AquilionONE CT. A soft plaque lesion is clearly visible in the proximal LAD. ] continues to develop. the newest systems offer significant improvements over earlier scanners and could make cardiac ct the test of choice for all patients with suspected coronary artery disease by producing superior quality images at a low radiation dose and eliminating the need for other studies such as nuclear stress testing for many patients. March 2008 | Health Imaging & IT 21 [ Toshiba’s AquilionOne CT system ] http://HealthImaging.com

Table of Contents Feed for the Digital Edition of Health Imaging & IT - March 2008

Health Imaging & IT - March 2008 Table of Contents On the Web The Enterprise: Communicating Better News Update Critical Test Results Management: The Human Touch The Changing Face of the Cath Lab Cardiovascular CT: A Clinical Boon Cardiology PACS: Solutions to Fit Your Needs ACC 08: Building Quality & Value Together Picking the Perfect PACS Displays PET/CT: A Game-Changer in Cancer Patient Management DR: You Gotta Have IT – Delivering Speed, Efficiency, Savings Laser Imagers: Answering the Call for Hard Copy Reader's Resources Stat Sheet

Health Imaging & IT - March 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.