Magnetic Resonance Venography (MRV)

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Magnetic Resonance Venography (MRV)

Magnetic resonance venography (MRV) is a diagnostic imaging test that is used to visualize veins in the body. Veins are the blood vessels that bring blood from your body's organs back to your heart and lungs so the blood can be replenished with oxygen and nutrients.

MRV is done using the same medical equipment that is used for magnetic resonance imaging (MRI.)

What Is MRI?

 

The large machine that is used for MRI tests uses a sophisticated and fascinating technique to create a picture that represents what is going on inside the body.

The MRI machine uses specialized magnets that 'read' information, which is then sent to a computer that has built-in, calibrated software that can interpret the information generated from the magnetic equipment. This information is used to recreate an image of the body, which your health care team can look at as they evaluate your medical problem.

An MRI machine can be adjusted to visualize images of different parts of the body, including shapes, solid areas, and blood or blood vessels. Sometimes an MRI is used to view tumors, traumatic injuries, and diseases such as stroke. Magnetic Resonance Angiography (MRA) is used to look at arteries and blood as it flows through arteries, while MRV looks at veins and blood as it flows through veins.

Why Would I Need Magnetic Resonance Venography?

MRV is used to assess blood flow in the veins and can detect blood clots or other abnormalities. Most of the serious blood vessel diseases - such as stroke and heart attack- are caused by problems with arteries, the blood vessels that bring oxygen rich blood to the body's organs, not by problems with the veins.

In general, disease of the veins is less common than arterial disease. And, more often than not, medical conditions that involve the veins tends to be less serious than conditions that are caused by arterial disease. That is why it is more common to hear about MRI (which creates a picture of the organ itself, not so much the blood vessels) or MRA (which is focused on creating a picture of the artery) than it is to hear about MRV.

If you need to have an MRV, it is likely that your doctor is evaluating you for a less common health problem that may take a while for diagnosis. Some of these problems include structural vein abnormalities or blood flow problems in the brain, developmental venous abnormalities in a very young baby, and blood clots that affect veins, rather than arteries.

Pregnant women have a slightly increased tendency to form blood clots that can result in a cerebral venous thrombosis, which is a blood clot in the veins of the brain. Overall, strokes and brain disease are highly uncommon in young women of childbearing age, but there is a slightly increased risk during pregnancy.

Sometimes, the brain structure of a developing baby or a young infant may not appear as expected, and a Brain MRV may give some insight into whether blood flow or abnormal structure of the veins could be a contributing factor. And conditions such as intracranial hypertension or normal pressure hydrocephalus (NPH) can cause neurological symptoms, which can be also be evaluated with MRV.

Contraindications For MRI/MRA/MRV

An MRI machine uses a magnet, and therefore you cannot have MRI, MRA or MRV if you have an implanted metal device in your body.

The force of the powerful magnet used in the MRI machine can cause serious problems, such as dislocation of the magnet or injury. Similarly, if you have a pacemaker, the magnet can cause the pacemaker to malfunction, with potentially serious consequences.

A Word From Verywell

Your MRV will be read and a report that describes the result of your test will normally be ready within a wekk after you go for the test.

MRV is not a common diagnostic test. If you are being evaluated for an uncommon medical condition, or if you have a medical problem that is taking a while to diagnose, you may be apprehensive about what to expect.

As you are going through this process, be sure to get the most out of your healthcare by asking questions and communicating with your healthcare team.

Sources:

Brain vein disorders in newborn infants, Raets M, Dudink J, Raybaud C, Ramenghi L, Lequin M, Govaert P, Dev Med Child Neurol. 2015 Mar;57(3):229-40

Brain Imaging in Idiopathic Intracranial Hypertension.Bidot S, Saindane AM, Peragallo JH, Bruce BB, Newman NJ, Biousse V, J Neuroophthalmol. 2015 Dec;35(4):400-11

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