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System Performance

Measuring Wait Times for Diagnostic Imaging


Priority levels and target times for waiting for diagnostic imaging services in Ontario are set by specialists and health care administrators across the province, based on clinical evidence, to guide treatment decisions and to improve patient access and outcomes.

Wait times are measured and reported from when a diagnostic imaging facility receives the request from the patient's doctor to book a Magnetic Resonance Imaging (MRI) or Computerized Tomography (CT) scan, to the patient having the scan.

Priority level of patient's condition

Clinical description

Target times from MRI or CT order received, to having the scan

Priority 1

Any condition in which failure to diagnose and initiate treatment would result in serious morbidity/mortality

Patient has the scan within 24 hours of order received; not included in wait times data

Priority 2

Any condition in which failure to diagnose/treat would result in significant deterioration/deficit

Patient has the scan within 48 hours of order received

Priority 3

Any condition in which failure to diagnose/treat would result in moderate deterioration/deficit

Patient has the scan within 10 days of order received

Priority 4

Any condition in which failure to diagnose/treat would result in minimal deterioration/deficit

Patient has the scan within 28 days of order received

Measurement Numbers Used for Diagnostic Imaging Wait Times

Data for the wait times for diagnostic imaging (MRI and CT scans) in Ontario is reported using these measurement numbers:

  • The average number of days patients waited for the scan; a lower number is better.
  • The percentage of patients scanned within the target time; a higher percentage is better.

Data Sources for Diagnosis Imaging Wait Times

The data comes from the Wait Time Information System™ (WTIS™), Cancer Care Ontario.

Time to CT or MRI Scan

How long adult and pediatric patients waited from doctor's request sent to diagnostic imaging facility, to having the scan.

Learn more

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