Download Technical Notes: Medical Imaging in Canada 2011

Technical Notes
Basic information on the National Survey of Selected Medical
Imaging Equipment is provided below.
Medical Imaging Equipment by
Province and Facility, 2011
Equipment Type Definitions
Computed tomography (CT): A diagnostic technique that
uses X-rays and computer technology to produce cross-sectional
images of the body (often called slices), both horizontally and
vertically. CT scans can show detailed images of various parts
of the body, including the bones, muscles, fat and organs. They
are more detailed than general X-rays.
Magnetic resonance imaging (MRI): A diagnostic technology
that uses a large magnet, radio waves and a computer to scan
a patient’s body and produce two- or three-dimensional images
of tissues and organs.
Positron emission tomography (PET): A type of nuclear
medicine that measures the metabolic activity of cells when
a radioactive substance produced by a cyclotron is injected
into a patient.
Gamma camera (gamma)—nuclear medicine: A device used
in nuclear medicine to scan patients who have been injected
with small amounts of radioactive materials.
Single-photon emission computed tomography (SPECT)—
nuclear medicine: A type of nuclear medicine that measures
the concentration of radio nuclides introduced into a patient’s
body. One or more gamma cameras rotate around the patient
and take pictures from many angles; a computer then uses the
pictures to form a tomographic (cross-sectional) image.
www.cihi.ca
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Technical Notes
Fusion technology—PET/CT: Fusion technology that combines functional and anatomical imaging
from PET and CT in the same display.
Fusion technology—SPECT/CT: Fusion technology that combines functional and anatomical
imaging from SPECT and CT in the same display.
Other Terms
Hospital: An institution where patients are accommodated on the basis of medical need and are
provided with continuing medical care and supporting diagnostic and therapeutic services. Hospitals
are licensed or approved as hospitals by a provincial/territorial government or are operated by the
Government of Canada. Included are those providing acute care, extended and chronic care,
rehabilitation and convalescent care, and psychiatric care.
Clinic (or free-standing imaging facility): Ranges from specialized services run privately by
physicians, radiologists, dentists, chiropractors or mammography programs to broad-based imaging
centres offering a wide range of tests.
What’s included: CIHI’s surveys from 2003 to 2007 and 2009 to 2011 (only the 2011 survey data is
shown in Quick Stats) tracked data on medical imaging equipment that was installed and operational
in Canadian hospitals and free-standing imaging facilities (sometimes also called non-hospital,
community-based and/or private facilities) as of January 1 of each year. The 2011 survey collected
information on CT scanners, MRI scanners, nuclear medicine cameras (gamma and SPECT), PET
scanners, PET/CT scanners and SPECT/CT scanners.
History: Over a period of many years, the Canadian Agency for Drugs and Technologies in Health
(CADTH), formerly the Canadian Coordinating Office for Health Technology Assessment (CCOHTA),
conducted a survey on the number, distribution and key characteristics of selected imaging
technologies in Canadian hospitals. Following discussions with CCOHTA, CIHI undertook a similar
survey in 2003 and conducted the survey annually thereafter, except in 2008.
The imaging equipment covered by the 2003, 2004 and 2005 surveys (angiography suites,
catheterization labs, CT scanners, MRI scanners, nuclear medicine cameras and PET scanners)
was the same as that surveyed by CCOHTA in 2001. Since 2006, two types of fusion technology
have also been included: 1) PET/CT scanners, which have been installed in Canada since 2002 and
combine functional and anatomical imaging from PET and CT in the same display; and 2) SPECT/CT
scanners, which were introduced in Canada in 2005.
Survey process: CIHI retained the services of ProMed Associates Ltd., a medical imaging consulting
firm, to coordinate data collection. ProMed contacted health regions, hospitals and relevant freestanding imaging facilities across Canada. Various organizations of health care professionals and
provincial/territorial ministries of health were asked to promote participation in the survey.
Respondents completed the online survey using a bilingual website. To maximize response rates,
ProMed completed several rounds of follow-up with respondents.
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Technical Notes
Validating the results: To ensure that the coverage was as complete as possible, responses were
cross-checked against results from previous surveys, published lists of equipment (such as research
reports and health directories) and data reported by hospitals and health regions to CIHI’s Canadian
MIS Database (CMDB). Provincial/territorial ministries of health were also asked to validate overall
equipment counts. In addition, ProMed reviewed information submitted and contacted participants for
follow-up where required.
Technical notes: 1) The numbers of MRI and CT scanners in free-standing imaging facilities were
imputed for years prior to 2003 based on data on years of installation collected in the 2003 National
Survey of Selected Medical Imaging Equipment. 2) Age of equipment is calculated from the year the
equipment was installed and in operation to January 1 of the current survey year.
Imputation of Exams
Exams from CT and MRI scanners that were not reported in the 2011 survey were imputed
according to the method below:
Option A: If exams were reported in the CMDB for the current year:
1. If the number of exams reported in the CMDB was within 10% (plus or minus) of the number of
exams reported in the survey in the previous year, use CMDB numbers.
2. If the number of exams reported in the CMDB was more than 10% (plus or minus) away from the
number of exams reported in the survey in the previous year, use the number from the previous
year’s survey.
Option B: If exams were not reported in the CMDB for the current year but were reported in the
survey in the previous year by the facility:
1. If the facility had the same number of pieces of equipment, use the previous year’s figure, adjusted
for the number of hours of operation, if available (using correlation between additional hours of
operation and additional number of exams, if possible).
2. If the facility had an additional piece of equipment, assume that this additional piece of equipment
was in operation half of the time and produced the same average number of exams as the
scanners in the facility, then add the extra exams to the previous year’s figure.
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Technical Notes
Option C: If exams were not reported in the CMDB for the current year and were not reported in the
survey in the previous two years by the facility:
1. Within the jurisdiction and the setting (free-standing versus hospital), compute the average
number of exams per scanner for all facilities.
2. Apply this average to each facility that had a scanner but did not report exams.
a. If the scanner was installed prior to the current year, apply the full average.
b. If the scanner was installed within the current year, assume it was in operation half of the time
and apply half of the average.
3. When, for a given jurisdiction and setting, exams were not reported by any facility, apply the
Canadian average number of exams per scanner for the setting.
Note: For Quebec, Option A does not exist, because this province does not report to the CMDB.
Cancer Care Facility
For non-reporting cancer care facilities, the number of exams is first imputed according to Option A
and Option B. If exams are not reported in the CMDB for the current year and were not reported in the
survey in the previous two years, compute the average number of exams per scanner for all cancer
care facilities within the jurisdiction. If no other cancer care facility is available, apply the Canadian
average of all cancer care facilities.
Calculation of Exams
For the total number of exams: Exams from all scanners are included, including those used
exclusively for research (this is consistent with the 2009 data release but different from the method
used in CIHI’s report Medical Imaging in Canada, 2007, where exams from scanners with less than
50% clinical use were excluded from the total number of exams). The rationale for the change is that
scanners used for research produce exams in the context of clinical trials; thus excluding them would
result in an underestimate of the total number of exams.
For the number of exams per scanner: In the numerator, include the exams from all scanners for
which exams were reported, including exams from scanners used exclusively for research. In the
denominator, have a weighted count of scanners for which exams were reported (for example, a
scanner used 60% of the time for clinical use would be 0.6 scanners). This approach avoids an
underestimate of this indicator, since scanners used mainly for research produce fewer exams and
should have less weight. This method is consistent with the 2009 data release but not with other
previous releases.
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