After blood tests have been used to measure the levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) and confirm the diagnosis of acromegaly, imaging techniques may be performed to find out if you have a tumour in the pituitary gland.
What imaging techniques are available?
Magnetic resonance imaging, abbreviated to MRI, is the best imaging method for this purpose. Another imaging technique that might be used is a computerized tomography or CT scan.
These imaging techniques can be carried out without you having to stay overnight in the hospital, although if you live far from the hospital you may need to arrange to stay somewhere overnight.
Almost all people with acromegaly confirmed by blood tests will have a pituitary tumour that is detectable on MRI. In most (more than two thirds) people the tumour will be around 1 cm across or larger (called a macroadenoma), with around one third of people having a tumour that is less than 1 cm (called a microadenoma).
Magnetic resonance imaging
MRI uses a magnetic field and pulses of radio waves to make pictures of the organs and structures inside your body.
MRI is used to identify normal and diseased tissue and is the best imaging technique that can be used to pinpoint the size and location of a tumour in the pituitary gland.
What happens during MRI?
You will have to lie very still on a bed inside the scanner for anywhere from 15 minutes to an hour.
Some people can feel claustrophobic, especially as the scanner may make a lot of noise. Speak to your doctor if you have a fear of being in small spaces or are anxious about being inside the scanner. They may be able to recommend something to help you or perhaps use a different imaging technique.
Can MRI be performed on everybody?
MRI can be done in the majority of cases, but there are certain people who may not be able to undergo this type of imaging technique. Usually MRI is not done during pregnancy.
Someone who has a medical device fitted, such as a heart monitor or pacemaker, may also not be able to undergo MRI. And someone who is very overweight might not fit inside a standard MRI scanner.
A CT or CAT (computerized axial tomography) scan is another type of imaging technique that can be used in the diagnosis of acromegaly to find out where the tumour is located within the pituitary gland.
CT scans use X-rays rather than radio waves to see the inside of the body.
A CT scan also displays detailed pictures of the body’s internal organs on a computer screen and can also provide useful information about the position and size of the tumour in the pituitary gland.
What happens during the CT scan?
Similar to an MRI, you will have to lie very still on a bed, but for only approximately 10 to 20 minutes. It consists of a ring that you place your head within.
Can CT be performed on everybody?
Unlike an MRI scanner, the CT scanner does not surround your whole body. It might, therefore, be more comfortable for people who suffer from claustrophobia or who cannot go inside a standard MRI scanner.
When will I get the results?
The results of your scan will need to be examined by a radiologist.
For both CT scans and MRIs, the radiologist will interpret the scan images and send a report to your doctor.
The doctor in charge of your care (usually the endocrinologist) will then discuss the possible treatment options with you.
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Find out how acromegaly is diagnosed and the tests that healthcare professionals may use to monitor acromegaly symptoms caused by excess growth hormone in the body due to a pituitary tumour.
Find out more about acromegaly
Learn about acromegaly
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