Diagnostic imaging

Uneven use of MRI, CT scans across Canada

OTTAWA – Diagnostic tests, such as magnetic resonance imaging (MRI) and computed tomography (CT) scans, are more commonly used on patients in some provinces than in others, according to new data released by the Canadian Institute for Health Information (CIHI).

For example, in 2009, rates of MRI exams performed in Alberta or New Brunswick were more than twice as high as those in Prince Edward Island or Newfoundland and Labrador, varying from highs of 54 exams per 1,000 people in Alberta and 51 per 1,000 in New Brunswick to lows of 23 per 1,000 in P.E.I. and 24 per 1,000 in Newfoundland and Labrador.

Similarly, the data shows significant variation among the provinces in the rates of CT exams performed on patients. New Brunswick and Nova Scotia had the highest rates of CT use (193 and 155 per 1,000 people, respectively) while P.E.I. and British Columbia had the lowest rates of use (104 and 106 exams per 1,000 people, respectively).

“By helping to detect disease in its early stages, medical imaging has helped save lives,” says Francine Anne Roy, Director of Health Spending and Clinical Registries at CIHI. “However, there are wide variations in the rates of use of these machines - both within Canada and throughout the developed world. Further research is required to determine the appropriate level of use of these technologies and to take full advantage of their diagnostic capability, while ensuring they are being used as efficiently and safely as possible.”

Number of machines continues to rise across Canada
As of January 1, 2009, there were 266 MRI scanners and 465 CT scanners operational in Canada. This represents an increase of 44 MRI and 46 CT machines over two years and an increase of 70% in the number of MRI scanners and 36% in the number of CT scanners since 2004.

In 2009, the majority of scanners (80% of MRI and 95% of CT scanners) were located in hospital settings, whereas 20% of MRI and 5% of CT scanners were in free-standing clinics, which are often privately funded.

CIHI data shows the number of diagnostic imaging machines relative to the size of the population varies significantly by province, as does the intensity of use of each machine. Some provinces, such as Ontario and Alberta, logged significantly more MRI exams per scanner than the national average.

Similarly, New Brunswick and Alberta used CT scanners more intensely.

Significant international variation persists
Internationally, there were larger variations across countries within the Organization for Economic Co-operation and Development (OECD) than across Canadian provinces in the number of MRI and CT exams performed relative to population size. In 2008-2009, the Canadian rate of MRI exams was 41 per 1,000 people, while for OECD countries the rate varied from a low of 13 in Korea to a high of 98 in Greece.

In the same year, the Canadian rate of CT exams was 121 per 1,000 people, compared to a low of 60 in the Netherlands and a high of 321 in Greece. For both MRI and CT exams, the United States had the second-highest rate of use at 91 and 228 per 1,000, respectively.

Quick facts
• In 2008-2009, the national rate of MRI exams was 41 per 1,000 people. Provinces ranged from highs of 54 (Alberta) and 51 (New Brunswick) to lows of 23 (P.E.I.) and 24 (Newfoundland and Labrador).

• In 2008-2009, the national rate of CT scans was 121 per 1,000 people. Provinces ranged from highs of 193 (New Brunswick) and 155 (Nova Scotia) to lows of 104 (P.E.I.) and 106 (B.C.).

• Ontario and Alberta used MRI scanners more intensely (more exams per scanner). New Brunswick and Alberta used CT scanners more intensely.

• In 2009, 80% of MRI and 95% of CT scanners were located in hospital settings; 20% of MRI and 5% of CT scanners were in free-standing clinics.

• By January 1, 2009, there were 266 MRI scanners and 465 CT scanners operational in Canada. There were 222 MRI and 419 CT scanners in 2007.

• In 2008-2009, the Canadian rate of MRI exams was 41 per 1,000 people. Among OECD countries, MRI rates varied from a low of 13 in Korea to a high of 98 in Greece.

• In 2008-2009, the Canadian rate of CT exams was 121 per 1,000 people. Among OECD countries, CT rates varied from a low of 60 in the Netherlands to a high of 321 in Greece.

• For both MRI and CT exams, the United States had the second-highest rate of use at 91 and 228 per 1,000, respectively.

About CIHI
The Canadian Institute for Health Information (CIHI) collects and analyzes information on health and health care in Canada and makes it publicly available. Canada’s federal, provincial and territorial governments created CIHI as a not-for-profit, independent organization dedicated to forging a common approach to Canadian health information. CIHI’s goal: to provide timely, accurate and comparable information. CIHI’s data and reports inform health policies, support the effective delivery of health services and raise awareness among Canadians of the factors that contribute to good health.

Posted July 29, 2010