About an MR angiogram of the visceral arteries
The visceral arteries branch off the aorta in the abdomen to supply the internal organs. They include the coeliac artery (supplying the stomach, liver and spleen), the superior and inferior mesenteric arteries (supplying the intestines) and the renal arteries (supplying the kidneys). An MR angiogram (MRA) uses a strong magnetic field, radio waves and a computer to make detailed pictures of these arteries, without X-rays and without passing a tube (catheter) into an artery.
These arteries can become narrowed by a build-up of fatty plaque. Narrowing of the arteries to the gut (mesenteric ischaemia) can cause tummy pain, often after eating, along with unintended weight loss. Narrowing of the kidney arteries (renal artery stenosis) can cause high blood pressure that is hard to control and reduced kidney function. Many people with mild narrowing have no symptoms. Risk factors include older age, smoking, high blood pressure, high cholesterol, diabetes and a family history of artery disease.
MRA does not use the iodine-based contrast used in CT angiography, which can be an advantage for some people with kidney problems; your specialist will consider your kidney function before contrast is given.
Referral needed: this scan requires a referral from a specialist, such as a vascular surgeon, stroke physician or other hospital consultant. You can upload the referral when you book.
What happens during the scan
You lie on your back on the scanner bed with a coil placed over your tummy. The scanner is loud, so you will wear ear plugs or headphones, and the radiographer can see, hear and talk to you throughout. You will need to keep your body very still, as even small movements can blur the pictures of the blood vessels.
Most MR angiograms use an injection of contrast dye (gadolinium) through a small cannula in a vein, usually in your arm or hand, so the blood vessels show up clearly. Gadolinium is less likely to cause an allergic reaction than the iodine-based dye used for CT. Some vessels can also be imaged without contrast. If you have contrast, you may be asked to wait for up to 30 minutes afterwards. Where contrast is needed, it is charged separately.
The visceral arteries move as you breathe, so you will be asked to hold your breath for short periods while some pictures are taken.
What the scan can show
An MR angiogram of the visceral arteries can help to look at:
- narrowing or blockage of the coeliac and mesenteric arteries (mesenteric ischaemia)
- narrowing of the renal arteries (renal artery stenosis)
- aneurysms of the visceral arteries, such as the splenic artery
- blood vessel anatomy before surgery or organ transplantation
- how well a stent or bypass is working after treatment
Small branches of these arteries can be harder to see on MRA. Your specialist will consider the results alongside ultrasound or other tests.
Sudden severe tummy pain? Sudden, severe abdominal pain needs urgent medical attention. Call 999 or go to A&E rather than waiting for a scan.
Preparing for your scan
You will usually be asked not to eat for a few hours before the scan, as an empty stomach and bowel give clearer pictures. The scanning centre will confirm this when you book. Because this scan normally uses contrast dye, let us know if you have kidney problems or have had a reaction to contrast before. If you have diabetes, tell us when booking.
You can usually eat, drink and take your normal medicines unless the scanning centre tells you otherwise. Wear loose, comfortable clothing without metal zips or buttons, and leave jewellery at home. You will be asked to remove metal items such as hair clips, hearing aids, coins and keys, and you may be asked to change into a gown.
Before the scan you will complete a safety questionnaire. Tell the team if you have a pacemaker, any metal implant, surgical clips or other device, if you have kidney problems or allergies, or if you are, or might be, pregnant or breastfeeding. If you feel anxious in enclosed spaces, let us know when you book. Some centres can offer a relaxant, and if you take one you will need someone to take you home and must not drive for 24 hours.
Frequently asked questions
Do I need a referral for an MR angiogram of the visceral arteries?
Yes. This scan requires a referral from a specialist. Please upload your referral when you book so the scanning centre can check that the right scan is arranged.
What is mesenteric ischaemia?
It is reduced blood flow to the intestines, usually because the mesenteric arteries are narrowed by fatty plaque. It can cause tummy pain after eating and unintended weight loss. An MR angiogram can show where the arteries are narrowed.
Can this scan look at the kidney arteries?
Yes. The renal arteries are visceral arteries, and MRA can show narrowing that may be causing high blood pressure or reduced kidney function.
Will I need a contrast injection?
Usually, yes. Contrast dye helps the arteries show clearly. It is given through a small cannula in your arm and is charged separately where it is needed.
Sources
- Ballad Health – Mesenteric and renal artery stenosis
- Meaney J.F. et al. – Gadolinium-enhanced MR angiography of visceral arteries in suspected chronic mesenteric ischaemia (J Magn Reson Imaging, 1997)
- RadiologyInfo.org – Magnetic Resonance Angiography (MRA)
- NHS – MRI scan
The information on this page has been gathered from various sources and is provided for general information only. It is not medical advice. TOP MRI is not liable for the accuracy or completeness of this information. Please speak to your doctor or the scanning centre about your own situation.