Sep 2 2008
Today, University Health Network (UHN) became the first institution in the world to have three 320-slice CT scanners, as Toronto Western Hospital's (TWH) scanner began clinical operation. The world's most advanced Computer Tomography technology, the 320-slice CT can cut time-to-treatment by two-thirds for stroke patients, help cancer specialists map tumours for treatment in greater detail than ever before, and allow cardiac disease to be diagnosed with unparalleled confidence.
“We have always been pioneers and early adopters of cutting edge CT technology,” says Dr. Patrice Bret, Radiologist-in-Chief at UHN. “Embracing this technology represents the next step in a continuum of technological advancement.”
Compared to traditional 64-slice CT technology, with an imaging area of 3.2cm, the 320-slice CT covers 16cm of anatomy, an area large enough to capture a full image of an organ and can show blood flow through specific areas of the body. Images are captured in 0.35 seconds with just one rotation of the scanner.
Stroke identification at Toronto Western Hospital
At TWH, the 320-slice CT is located in the emergency department, the only installation of its kind in the world. In an environment where every second counts, the speed of the scanner greatly benefits patients with serious trauma and those exhibiting signs of stroke.
“Installing this machine in the emergency department will allow us to more accurately triage patients,” says Dr. Karel Terbrugge, Medical Imaging Site Director at TWH. “We felt very strongly that emergency patients should have access to this technology.”
For stroke patients, the new CT will lower time-to-diagnosis from approximately one hour to about 20 minutes. “We can now very quickly get a complete image of the brain and assess if a patient will benefit from revascularization treatment for stroke,” says Dr. Terbrugge. The length of time between the occurrence of a stroke and receiving treatment is directly related to the amount of damage to the brain.
Dr. Terbrugge is leading an international research study involving 10 teaching hospitals that will evaluate the medical outcomes of stroke patients triaged with the 320-slice CT, compared to historical data on outcomes of patients triaged using traditional MRI technology.
Cancer treatment mapping at Princess Margaret Hospital
At Princess Margaret Hospital (PMH), the 320-slice CT will be used to target tumours for radiation therapy treatment with greater accuracy.
“The 320-slice CT will allow us to measure breathing-induced motion of both tumours and normal tissues within the patient,” says Dr. David Jaffray, Head of Radiation Physics at PMH. “With this information, we can accommodate for movement and develop highly precise radiation treatments that induce minimal side-effects.”
The 320-slice scanner also offers new knowledge about the nature of blood flow through cancerous tissue. Combined with the high-quality images produced by the scanner, radiation oncologists will be better able to determine the appropriate level of radiation for treatment and assess a patient’s response to therapy.
“If you think of a tumor as a city and blood flow as traffic, the complexity of the roads entering the city results in a slowing of traffic. This technology allows us to see subtle delays in blood flow and thereby get a representation of the size of the tumour,” says Dr. Jaffray.
Cardiac diagnostics at Toronto General Hospital
In 2007, UHN’s first 320-slice CT went into operation at the Peter Munk Cardiac Centre located at the Toronto General Hospital (TGH) and at the time, was one of only five in the world.
Since then, radiologists at TGH have seen significant radiation dose reduction for cardiac patients and are better able to diagnose cardiac disease, because a complete image of the heart can be captured in less than one second.
“Breathing artifact, which causes image blurring, has been reduced with the 320-slice CT. This means that we have better diagnostic confidence,” says Dr. Narinder Paul, Medical Imaging Site Director at TGH. “We’re at the point where we can start to look past anatomy and start to look at organ perfusion.”
Through the use of the 320-slice CT, radiologists at UHN hope to open the field for more new applications of the technology, such as examining brain perfusion, the prevention of cardiac disease, and surgical treatment mapping.