Thallium Study

What is it?

'Thallium study' is a general term used for 'Stress myocardial perfusion scintigraphic study', a test which is aimed at viewing the distribution of blood to the heart muscle. The distribution varies between a patient with previous heart attack, a patient of angina and a normal individual. Thallium 201 (Tl201) and Technicium 99m (Tc99m)- radiopharmaceuticals are used for this study. These radiopharmaceuticals map the distribution of blood supply to the heart muscle when imaging is done using a Gamma Camera/SPECT.This is performed on exercise and at rest.

Before starting to exercise, the patient receives an injection of thallium 201, a radioactive chemical, which is taken up by normal heart muscle cells:

• Immediately after exercise, heart scans are performed.
• If muscle tissue is damaged by ischemia (oxygen deprivation), it will fail to take up thallium and will be detected on the scanned image
• If the scan detects damage, it is repeated two or three hours after exercise.
• Damage due to a prior heart attack will persist when the heart scan is repeated. Injury caused by angina, however, will have resolved by that time

Why is it done?

• To accurately delineate the distribution of blood to the heart muscle during rest and exercise.
• This is helpful in assessing the stress-induced reduction in blood supply on exercise, to a region of the heart muscle.
• This determines the severity and extent of ischaemia (reduced blood supply).

   

How is it done?

The patient is asked to do exercise on a treadmill under clinical monitoring.
Gamma ray emitting medical radioisotope, which maps the heart muscle, is injected by a simple intravenous injection into a superficial vein of the arm.

• A study is acquired under the Gamma Camera/ SPECT after exercise and at rest (1st & 2nd phase).
• Analysis of the study is performed on a computer and a report is generated.
• A third phase of the study may be done on the next day if required (for this the patient has to come at the given time, for about 2 hrs, without any particular preparation)
• Report is given to the patients after 2 working days.

When it is done/advised?

• Diagnosis of Ischaemic heart disease/ Coronary artery disease.
• Assessment of presence, severity and extent of ischaemia due to coronary artery disease detected by angiography. This helps in deciding the line of treatment.
• For follow and assessment of patients after CABG or PTCA.
• Detection of hibernating ('revivable') myocardium (immobile yet living heart muscle) in patients who already had infarction ('Heart attack').

Before ... Precautions & prerequisites

Preparations for the service:

Take an appointment for the study as mentioned above.
Follow the instructions given, which generally are as follows:
Come fasting on the day of the test at 9:00 am or as advised (Water can be taken).
(Liquids / light solid food is allowed after the 1st phase of the study is done)
Stop/ allow cardiac medicines on the day of the test as advised (Please keep the medicines with you).
Bring your old medical records.
An adult/ responsible attendant should accompany the patient.

The appointment is strictly subject to the availability of the radioactive medicine (Tl201/Tc99m). Please confirm the availability of the medical radioisotope according to the instructions given.

* Department/ hospital is not responsible for last-moment non-availability of medicinal radioisotope due to reasons beyond our control.

Tariff

Stress Thallium:
Rs. 8000/-
+ (optional) Rs 80/- for Thallium alert card

Rest Thallium:
Rs. 5000/-
+ (optional) Rs 80/- for Thallium alert card