Imaging Physics promotes acceptable practice in medical imaging physics and maintains the level of professional standards defined by the Canadian Organization of Medical Physics and the Canadian College of Physicists in Medicine. Imaging recognizes the Canadian College of Physicists in Medicine as an accrediting body.

Key Functions

The key functions of Imaging Physicists include the following:

1. Optimize the imaging characteristics of medical imaging equipment.

• develop and supervise QA programs
• ensure the safe operation of equipment
• help diagnosis problem systems
• advise on user protocols used by the system

2. Provide technical expertise to purchasers of medical imaging equipment.

• formulate technical specifications that potential equipment must meet
• perform a technical assessment of equipment in order to purchase the most cost-effective instrument
• perform acceptance testing to ensure that equipment performs as promised

3. Provide independent technical advice to Manitoba Health with respect to imaging equipment.

• advice concerning new equipment and technology
• advice concerning serviceability of existing equipment
• advice concerning upgrading or replacing existing equipment

4. Provide physics education to physicists, physicians, graduate students, technologists, and residents.

5. Perform research in medical imaging physics.

• develop new imaging devices
• develop new clinical techniques
• assess existing techniques
• develop image processing and display techniques

Key Imaging Equipment (Modalities)

Photograph showing typical phantoms used
for testing diagnostic x-ray equipment.>

The imaging equipment that we are most familiar with includes the following:

Ultrasound

Ultrasound uses high frequency (typically 2 to 13 MHz) sound to make images of soft tissues and measure blood flow. It is very safe, fast and relatively inexpensive.

Poor quality ultrasound image
showing a large black streak caused by a faulty probe.

MRI

MRI uses a large static magnet along with time-varying magnetic fields to make images. It is very versatile and is particularly important in imaging the head and spine. Although very safe, it is also very expensive and somewhat slow.

Magnetic resonance image showing
a huge amount of geometric distortion.
The image of the phantom should be circular.

CT

CT uses x-rays to make cross sectional images. It is somewhat expensive and evolving rapidly.

Good quality image of a contrast-detail phantom made by x-ray computed tomography. How many white circles can you see?

Mammography

Makes very-high resolution x-ray images of the breast. Currently most systems use film although digital instruments are available.

X-ray mammography image of a standardized phantom. Image quality is evaluated by the number of targets that can be seen.

Nuclear Medicine

Radioactive-labelled compounds are injected into a patient and their distributions recorded using a gamma-camera or PET camera. It provides excellent functional information but is slow.

Nuclear medicine image: the large white "X"
is due to a damaged detector crystal.

Fluoroscopy

An x-ray technique for making dynamic images (movies) of moving structures such as the heart.

X-ray tube with a cracked anode due to misuse.

Computed Radiography

A filmless method for making x-ray images.

General Radiography

Consists of standard film-based and fluoroscopic x-ray systems. It also includes the film processors.

PACS and Teleradiology

Includes the software and hardware required to store, retrieve, transmit, display and process medical images within a facility or between facilities. It is replacing film.