Magnetic resonance imaging, abbreviated to MRI, is the best imaging technique for this purpose. Another imaging technique that might be used is a computerised tomography or CT scan.
These imaging techniques can be carried out without you having to stay overnight in the hospital, although if you live a long way from the hospital you may need to arrange to stay overnight somewhere.
Both MRI and CT scan require the injection of a contrast media to help identify the pituitary tumour from the normal pituitary tissue and other surrounding structures.
Most people will tolerate the injection of this contrast medium well, but you will be asked about your previous history of allergic reactions to ensure that this causes no unwanted effects.
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).
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.
MRI is painless, but you will have to lie very still on a bed inside the scanner for about 30 to 60 minutes.
There are no known harmful effects. 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.
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 (computerised axial tomography) scan is another type 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.
CT is also painless. Similar to MRI you will have to lie very still on a bed, but for around 10 to 20 minutes. It consists of a ring that you place your head within.
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.
The results of your scan will need to be examined by a neuroradiologist.
The neuroradiologist will talk to the other members of the multidisciplinary team in charge of your care.
The doctor in charge of your care (usually the endocrinologist) will then discuss the possible treatment options with you.
This process can take anything from a few days to a few weeks.
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