Ontario Breast Screening Program

Funded by the Ministry of Health and Long Term Care and managed by Cancer Care Ontario, the Ontario Breast Screening Program (OBSP) provides province wide, high-quality, OHIP-covered breast screening mammography services. The OBSP offers important advantages for women and their primary care providers including scheduling of all screening appointments, sending recall and result letters to women, and arranging follow-up services for women with results that require further testing.

Screening Mammography is the best screening test for most women and plays an important part in early detection of breast cancer. Regular screening mammograms can detect cancer in its early stages which means there may be more treatment options, that is less likely to spread and a better chance of treating the cancer successfully.


Women ages 50 to 74 are encouraged to have a mammogram every two years to detect changes in breast tissue that are too small to feel or see.

The OBSP Program does not require a requisition from your doctor however, the following requirements must be met to be a part of the program:

  • No new breast symptoms
  • No personal history of breast cancer
  • No current breast implants
  • Have not had a screening mammogram within the last 11 months

Women over the age of 74 who meet the above requirements can still take part in the program with a physician requisition.

Patient Information: What to Expect with Your Mammography

Preparing for Your Mammography:

  • If possible, avoid scheduling your mammogram for the week before your period if your breasts are usually tender during this time
  • The best time for a mammogram is one week after your period
  • Bring all mammograms completed outside of NBRHC. If notified prior to your appointment we can support with arrangements to obtain images

The Day of your appointment:

  • Continue to take your medications as normal
  • Arrive 15 minutes before your appointment time for registration
  • Bring your health card
  • If you are over the age of 74, bring your requisition
  • Dress accordingly for removal of clothing from the waist up
  • NBRHC is a “Fragrance Free” facility. To avoid a false reading please do not wear deodorant, talcum powder or lotion under your arms or on your breasts

During your Mammogram:

  • You will be asked to undress to the waist and given a loose-fitting gown to wear
  • A qualified medical radiation technologist will position your breast in the mammography unit
  • Your breast will be compressed slowly with a clear plastic or plexiglass paddle
    *The compression, which typically lasts only a few seconds, will be firm and may at times be uncomfortable
  • It’s important to remain still during the entire procedure
  • Four images will be taken in total (2 of each breast; top to bottom and angled side)

Breast compression is necessary to:

  • Even out the breast thickness so that all the tissue can be visualized
  • Spread out the tissue so that small abnormalities are less likely to be hidden by overlapping breast tissue
  • Allow the use of a lower x-ray dose with thinner amounts of breast tissue being imaged
  • Hold the breast still in order to minimize blurring of the image caused by motion
  • Reduce x-ray scatter to increase sharpness of the picture

After your Mammogram:

  • No restrictions
  • Images will be analyzed and reports mailed to you and the primary care or referring physician

Frequently Asked Questions:

Are there any tests that are better than a mammogram?
Studies have shown that ultrasound and magnetic resonance imaging (MRI) combined with mammography can aid in diagnosis of breast concerns. However, both MRI and ultrasound show more findings that are not cancer, which can result in added testing, stress and unnecessary biopsies. Mammography remains to be the gold standard for breast cancer screening for most women.

What is dense breast tissue?
Breasts contain glandular, connective and fat tissue. Breast density is a term that describes the relative amount of these different types of breast tissue as seen on a mammogram. Dense breasts have relatively high amounts of glandular tissue and fibrous connective tissue and relatively low amounts of fatty breast tissue.

Do I need to wear a thyroid collar for a mammogram?
A mammogram is a low dose x-ray of the breasts. The x-ray dose from a mammogram is very low and the exposure to the thyroid is negligible. Thyroid exposure has been carefully studied and is so small that it is equivalent to 30 minutes of background radiation (the naturally occurring radiation we all get every day from the environment).  There is no risk to the thyroid during a mammogram and a thyroid shield is not necessary to wear during the exam.

Should I be concerned with the radiation exposure during a mammogram?
Today, modern mammography equipment produces high quality breast images with low doses of radiation. The total dose for a mammogram with two views of each breast (four pictures) is about 0.4mSv. The average annual effective dose from natural background radiation is about 1.8mSv in Canada and 2.4mSv worldwide.

Whenever having a medical procedure that involves radiation, an individual must always measure the risk vs the benefit. The benefit of an accurate diagnosis far out weights the risk.

Screening Mammography Recommendations for Women Receiving the COVID-19 Vaccine

Screening mammograms and COVID-19 vaccines are both very important for your health – click here to learn more!



Ontario Breast Screening Program
Level 200

Tel: 705-495-7930
No Physician referral necessary

Hours of Operation:

Monday to Thursday
7:00 am to 3:00 pm
Once a month our hours are 11:00 am -7:00 pm (usually the last Monday).

North Bay

50 College Drive,
P.O. Box 2500
North Bay, ON
P1B 5A4
Tel: 705-474-8600

feature buttons


680 Kirkwood Drive,
Sudbury, ON
P3E 1X3
Tel: 705-675-9193
Fax: 705-675-6817

feature buttons

Floor Plans

Let us guide you to where you need to go.

Visitors Guide

feature buttons