Medical Diagnostic Unit (MDU)

***The Medical Diagnostic Unit is located in the North Tower in Diagnostic Imaging 1N700*** 

The Medical Diagnostic Unit (MDU) at Joseph Brant Hospital consists of five clinical laboratories, which provide specialized tests for both inpatients and outpatients. Each laboratory is equipped and staffed to facilitate diagnosis of patients referred with suspected or known disease of the cardiac, respiratory, neurological and neuro-muscular systems.

Medical Diagnostic Unit (MDU) provides the following tests:

  • Cardiac Stress test
  • Echocardiography (ECHO) - Including Stress Echo
  • Electroencephalography (EEG)
  • Electromyography (EMG)
  • Nuclear Cardiology
  • Pulmonary Function (PFT)

Hours of Operation:

The MDU department is open for outpatient examinations from 8:00 a.m. to 4:00 p.m. Monday to Friday.

Your visit may take anywhere from a half-hour to one and a half hours, depending on your particular type of test. On the day of your test(s), you should continue taking your medication(s), unless otherwise indicated by your family doctor or the ordering physician. You may have to fast depending on the type of test. For Cardiac Stress tests and EEGs, you cannot drink caffeine on the day of the test. For specific details, check with the MDU department.

Patients having different exams sometimes use the same waiting room. The time order in which you arrive and register does not necessarily indicate the order in which you will be called for your appointment. You will be called to the appropriate area to have your procedure when a room is available. Although every effort will be made to complete your examination at the appointed time, urgent and emergency cases will be completed first and there may be times when your exam may be delayed.

Contact Us:

Main department telephone line, general inquiries and bookings 905-336-4126

About certain exams:


The EEG provides information necessary for the diagnosis, prognosis and therapy of patients who are suspected of having a wide range of neurological problems: headaches, migraines, seizures, brain tumours, cerebrovascular, metabolic or toxic disorders, infectious or degenerative disease of the brain.


The EMG tests are used to determine the cause of muscle weakness, paralysis, abnormal numbness, tingling or pain. The test determines whether the problem is in the muscle, spinal cord or nerves to the muscle.


Respiratory status is assessed using Pulmonary Function Testing, which assists in the diagnosis and assessment of pulmonary (lung) disorders. Pulmonary Function testing provides the basis for classifying pulmonary diseases into three major physiologic categories: obstructive, restrictive and combined. Obstructive diseases are emphysema, chronic bronchitis and asthma. Restrictive diseases are fibrosis, pneumonia, pulmonary edema, sarcoidosis and asbestosis. 


The tests determine if the heart is receiving adequate amount of blood and oxygen during exercise. There are a number of tests that are available to physicians depending on the patient's presentation.


An echocardiography or "echo" is an ultrasound examination of the heart. M-mode echo allows accurate measurement of the heart chambers. Two- dimensional (2-D) Echo is capable of displaying a cross-sectional "slice" of the beating heart, including the chambers, valves and the major blood vessels that exit from the left and right ventricle. The echo provides the size of the chambers of the heart, including the dimension or volume of the cavity and the thickness of the walls. It also measures the pumping function of the heart. One can tell if the pumping power of the heart is normal or reduced to a mild or severe degree. This measure is known as an ejection fraction or EF.

Transesophageal Echocardiography (TEE)

The echo transducer is placed in the esophagus. Since the esophagus sits behind the heart, the echo beam does not have to travel through the front of the chest. It offers a much clearer image of the heart, particularly, the back structures, such as the left atrium, which may not be seen as well by a standard echo taken from the front of the heart.

Medical Diagnostic Unit Requisitions & Referrals

For Physicians:

Below are PDF copies of the Medical Diagnostic Unit Requisitions. Please complete, print and fax to 905-681-4805. For hard copies of these requisitions please contact 905-336-4126.

Requisition forms:


Contact Us:

Joseph Brant Hospital
1230 North Shore Blvd.
Burlington, ON L7S 1W7


P: 905-632-3737