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MRA stands for Magnetic Resonance Angiography. It is an MRI technique that specifically evaluates vessels such as arteries. Renal artery MRAs evaluate the vessels that supply blood to the kidneys to look for narrowing and blockage of the vessels, evaluate a suspected aneurysm, or look at the the blood supply of a kidney tumor.

(FYI: "renal" is another word for kidney).

Renal MRAs are typically ordered for the evaluation of hypertension and kidney failure that can be caused by blockages and narrowing of the arteries. If a kidney receives less blood flow it may "act" as if there is not enough blood in the body and release hormones that try to raise the blood pressure. If one or both kidneys has low flow, over time the kidney tissue becomes damaged and is unable to function leading to renal failure.

Renal MRAs can diagnose:

Plaque - Renal MRAs can detect plaque deposits that overtime can narrow the vessel leading to reduced blood flow to the kidneys. Some plaque can abruptly "tear" off sending bits of plaque into the kidneys, blocking vessels and causing a "stroke" of the kidneys. This can lead to kidney scarring.

Dissection - This refers to a tear in the wall of the vessel. Think of it as a tear of the inner lining of the sleeve of a jacket. If you filled the inner lining of your jacket with down it would block the real opening for your arm.  In the artery the blood goes into the opening of the tear of the dissection, expands the false channel, potentially blocking the flow of blood to the kidney and resulting in low flow to the kidney and damage to the tissue.

Aneurysms and Vascular Tumors - Aneurysms are ballooning of the vessels that can either disturb normal blood flow, press on nearby tissue or rupture. Renal vascular tumors may be picked as the vessels that feed them are large enough to be seen on the MRA.

An MRA of the renal arteries will evaluate:

Renal arteries

Each kidney has between 1 to 2 arteries that come off the sides of the abdominal aorta (see the picture to the right). These short and relatively small vessels can be narrowed by plaque, become inflamed or be affected by dissections and aneurysms.

Abdominal Aorta

The abdominal aorta is the main feeding artery for your body below your diaphragm. A renal MRA will include this vessel and can detect major abnormalities like aneurysms, dissection, plaque and blockages.

Abdominal Aorta branch arteries

In addition to seeing the renal arteries, the MRA will also see the other branch vessels which include the celiac artery, superior mesenteric artery and inferior mesenteric artery among others. These vessels supply other organs including the liver, gallbladder, pancreas, spleen, adrenals, stomach, etc.

Your Renal artery MRA Scan

A Renal artery MRA generally takes about 15-30 minutes or so to complete. If you are going for one, wear loose comfortable clothing and remember to remove all metal (jewelry, phones, rings, etc) before going into the MRI scan room.  This test is occasionally done with IV MRI contrast.

If you're insured, you may need to have your test authorized (approved) by your insurance company first. If you're uninsured and need to look up prices and buy an MRA scan of the renal arteries, you can use our website to look up MRA scan costs and then purchase with your credit card.

Have you had a Renal MRA scan? What was it like? Please leave your comments below.

MRI scans are frequently used to evaluate the internal structures of the hip joints. A variety of trends have increased the use of MRI in evaluating joints - more sports activity, increase in obesity rates, and we've remained much more active into our later years than previous generations.

If you've injured your hips or have chronic hip pain, your doctor will probably first order an x-ray. After an x-ray, an MRI may be needed to evaluate the internal structures of the hip. On your doctor's order for the MRI you might see:

"r/o internal derangement" -  internal derangement is a general term referring to any type of injury/damage to the internal structures of the hip. The labrum (a ring of cartilage in the hip joint) can be torn or frayed, causing pain or clicking.

"r/o fracture"- some hip fractures are not seen on x-rays and may only show up on an MRI. MRI is very good at picking up "edema" or swelling in the bone.

"r/o djd" - djd is short for degenerative joint disease. These are changes in the bone, labrum, and cartilage of the hip that can occur as we age or after an old injury to the hip.

(FYI - "r/o" is short for "rule out")

An MRI of the hips will evaluate:

Bones

A hip MRI will include parts of the upper femur, acetabulum (groove for the femur in the pelvis) and nearby pelvic bones. The hip MRI can detect bone bruises, fractures, cysts, tumors, infection and dislocations. An MRI can also determine the extent of arthritis and help in pre-operative planning.

Cartilage

Hip MRIs are very good at looking at the cartilage and labrum (a ring of cartilage) in your hips. MRI can detect fraying (like frayed edges of jeans), fissuring (cracks, similar to a dry river bed), and defects (the cartilage is missing). Damaged cartilage or injury to the labrum can lead to arthritis. Some hip MRIs are done with a direct injection of contrast material into the joint to get a detailed look at the cartilage and labrum.

Tendons and Ligaments

Your hip has many nearby tendons and ligaments that help with motion and stabilize the joint. Any of these can be injured and may only be detected on MRI.

Soft Tissues

This refers to the muscles and tissues around your hips. A hip MRI scan will show parts of the thigh muscles and muscles of the buttocks area. MRI can detect muscle tears, strains, tumors and infection.

Your Hip MRI Scan

A standard hip MRI generally takes about 20 minutes or so to complete. If you are going for one, wear loose comfortable clothing and remember to remove all metal (jewelry, phones, rings, etc) before going into the MRI scan room. If you're insured, you may need to have your test authorized (approved) by your insurance company first. If you're uninsured and need to look up prices and buy an MRI scan of the hip, you can use our website. Click here to see MRI scan costs.

Have you had a Hip MRI scan? What was it like? Please leave your comments below.

CT scans and MRI scans are high tech imaging studies that give doctors the ability to look at the internal anatomy of the body in great detail. One of the tools used to help in differentiating normal structures from abnormal structures like tumors, aneurysms, infection, is IV contrast dye. The dye used in CT scans is based on low osmolar contrast material and for MRI scans on gadolinium. The dye is injected through an IV catheter placed in a vein (usually in the arm or hand). The contrast highlights different tissue types bringing out vessels, tumors, inflammation, cysts, etc, that might be missed if the dye was not administered for the scan.

Many patients are unaware of the side effects of the dye or misinformed (and uninformed) about the risk of contrast administration. A recent contrast injection study by the Mayo Clinic in Rochester, MN looked back at over 450,000 dye injections. Below is a brief summary of their experience:

• CT scan dye side effects were 0.15%
  
• MRI dye side effects were 0.04%
  
• Most common side effects were hives and nausea
• 19 patients had a severe side effect (requiring medication, treatment)
• 1 patient died which is a mortality risk of 0.0003%

Clearly there is a risk of a severe reaction to the dye or even death. However, as the Mayo Clinic reports the vast majority of their patients did not have a reaction.

Although reactions to contrast are rare, it is standard practice to inform you of the possibility of dye administration and its potential side effects. However, keep in mind that many imaging facilities will not have a verbal discussion with you regarding IV contrast administration. It's usually in the paperwork you fill out before the test. Make sure you read and understand what you are signing in advance!

Have you had a contrast dye injection? What was your experience like? Leave your comments below.

MRI scans are frequently used to evaluate the internal structures of the brain. IAC MRIs are a type of Brain MRI that is used to evaluate the structures of the Internal Auditory Canal - IAC (aka Internal Auditory Meatus - IAM).

The IAC contains among other structures the 8th cranial nerve. This is a large nerve that conducts hearing and balance signals from your inner ear structures. This nerve can become damaged, inflamed or give rise to a tumor commonly called an "acoustic neuroma." Most IAC MRIs are ordered to rule out an acoustic neuroma in patients who are experiencing dizziness, ringing in the ears, hearing loss, fullness, for example. Although these tumors are slow growing and generally benign, they are close to vital structures in the brain and can be difficult to treat.

An MRI of the IACs is done with MRI dye. The dye helps detect small tumors and subtle inflammation that a non-contrast MRI may miss.

IAC MRIs also include the cerebellum, brainstem, vessels of the back of the brain and other nearby structures. Some IAC MRI protocols also include a few scans of the entire brain.

Your MRI IAC Scan

An MRI of the IACs generally takes about 30-40 minutes or so to complete. If you are going for one, wear loose comfortable clothing and remember to remove all metal (jewelry, phones, rings, etc) before going into the MRI scan room.

This test will be done with IV MRI contrast. The first part of the test is done without contrast. Then the scan is paused and the table on which you are lying will be pulled out (remember don't move!). The technologist will then inject the IV dye and return the table into the tube for the remainder of the scan.

If you're insured, you may need to have your test authorized (approved) by your insurance company first. If you're uninsured and need to look up prices and buy an MRI scan of the IACs (IAMs), you can use our website to look up MRI scan costs and then purchase with your credit card.

Have you had an MRI of IACs scan? What was it like? Please leave your comments below.

MRI scans make buzzing and clicking noises. They can be very loud and patients are often given ear plugs to dampen the noise. Open MRI units make similar noises but are not as loud. Below is a short clip from a closed MRI thanks to Dr. Hess and his wonderful Google Knol on brain MRI and CT. As Dr. Hess explains in his post, the noise is not from moving parts but from electronic switching of magnetic coils.

You may want to adjust your computer speaker volume before playing the clip.

MRI scans are frequently used to evaluate the internal structures of the brain. Brain MRIs are not only used to discover tumors, infection and chronic diseases but also are now increasingly used in acute settings to look for bleeds and stroke.

Brain MRIs are typically ordered for many different symptoms to exclude a tumor, aneurysm or unusual infection and as a follow up for stroke, surgery, etc. Below are a few common diagnoses that brain MRIs can pick up.

Aneurysm - Aneurysms are ballooning of vessels that risk rupturing. If blood leaks from the aneurysm patients describe the headache as a thunderclap and sharp/shooting pains. Patients can also have stroke-like symptoms with weakness, slurred speech and confusion. These MRI scans are usually done without contrast but also with an MRA which gets a more detailed look at the vessels of the brain.

Tumor - Tumors can be primary (from brain tissue) or secondary (from other sites, eg breast cancer). These typically present with headaches, weakness, and seizures. These MRI scans are done with contrast to help highlight and characterize the tumor.

Infection - Brain infections present with headaches, fever, stiff neck (meningitis). Some infections can be chronic such as tuberculosis (Tb). If looking for infection the MRI is typically done with contrast.

Stroke - Also known as a "brain attack", stroke refers to a blocked artery that deprives a part of the brain of blood (and therefore oxygen). This part of the brain loses it function and patients present with weakness, slurred speech, difficulty walking and on occasion, headaches.

An MRI of the brain will evaluate:

Sinuses

A brain MRI will include parts of the sinuses. Though not used to primarily look for sinus disease, an MRI can see thickening of the sinus tissue (mucosa) or fluid in the sinuses.

Orbits

Brain MRIs include the orbits but are not tailored to specficially look at the orbits. This requires a dedicated Orbit MRI which uses different sequences (sequence is a type of image) to look at the internal structures of the orbits. Nevertheless, it can pick up some disease of the orbits such as large tumors, bleeds, inflammation, etc.

Bones

Brain matter

The white and gray matter of the brain are well seen. MRI can detect tumors, infection, bleeds, stroke and congenital defects. Part of the pituitary gland, optic nerves and upper brainstem are also evaluated. A "routine" brain MRI is done without contrast.

Ventricles

These are the fluid filled structures inside the brain that help circulate cerberospinal fluid. Tumors and bleeds can extend into these structures and cause blockage which can lead to headaches, confusion and problems with walking for example. 

Your Brain MRI Scan

A brain MRI generally takes about 20 minutes or so to complete. If you are going for one, wear loose comfortable clothing and remember to remove all metal (jewelry, phones, rings, etc) before going into the MRI scan room. If you've had surgery or have a history of cancer, you'll probably have the test done with IV MRI contrast.

If you're insured, you may need to have your test authorized (approved) by your insurance company first. If you're uninsured and need to look up prices and buy an MRI scan of the brain, you can use our website to look up MRI scan costs and then purchase with your credit card.

Have you had a Brain MRI scan? What was it like? Please leave your comments below.

MRI scans are frequently used to evaluate the internal structures of the shoulder. A variety of trends have increased the use of MRI in evaluating the shoulder - more sports activity, repetitive motion injuries, and we've remained much more active into our later years than previous generations.

If you've injured your shoulder or have chronic shoulder pain, your doctor will probably first order an x-ray. After an x-ray, an MRI may be needed to evaluate the internal structures of the shoulder. On your doctor's order for the MRI you might see:

"r/o rotator cuff tear" -  the rotator cuff is a group of muscles, ligaments and tendons that stabilize and move your shoulder. These structures are frequently injured or damaged over time. The most commonly injured tendon is that of the supraspinatus muscle.

"r/o labral tear"- this refers to injury to the cartilage in your shoulder joint. The labrum stabilizes the shoulder and can be torn. Labral tears cause pain and "catching."

"r/o djd" - djd is short for degenerative joint disease. It is a generic term that is used to look for a number of shoulder problems including chronic changes to the tendons, ligaments, and bones. 

(FYI - "r/o" is short for "rule out")

An MRI of the shoulder will evaluate:

Bones

A shoulder MRI will include the ball and joint socket of the shoulder (humerus and glenoid), parts of the scapula and upper arm. The shoulder MRI can detect bone fractures, tumors, infection and evaluate post-surgical changes. An MRI can also determine the extent of degenerative changes (arthritis) and be used for pre-operative planning for surgery.

Cartilage and Labrum

Shoulder MRIs can also evaluate the cartilage of the shoulder joint and the labrum. The labrum is a stabilizing piece of cartilage which can be torn or irritated and cause pain.

Tendons and Ligaments

Your shoulder is stabilized and moves via complex set of tendons and ligaments. These can be frequently torn, partially torn or exhibit signs of age (degeneration) that leads to pain or difficulty in moving the shoulder joint. The rotator cuff includes the group of tendons around the shoulder joint.

Soft Tissues

Soft tissues visualized include muscles such as the supraspinatus, infraspinatus, deltoid, subscapularis, and teres minor. MRI can detect muscle tears, strain, atrophy, tumors and infection. Shoulder MRI can also detect joint fluid, lymph nodes in the axilla (armpit) tumors or cysts in the suprascapular notch (this is a small pathway through which a nerve passes to supply muscles of the back of your shoulder).

Your Shoulder MRI Scan

A shoulder MRI generally takes about 30 minutes or so to complete. If you are going for one, wear loose comfortable clothing and remember to remove all metal (jewelry, phones, rings, etc) before going into the MRI scan room. If you've had surgery or have a history of cancer, you'll probably have the test done with IV MRI contrast. Some shoulder MRIs are done after a direct injection of contrast into the joint. This is called an MR Arthrogram of the Shoulder.

If you're insured, you may need to have your test authorized (approved) by your insurance company first. If you're uninsured and need to look up prices and buy an MRI scan of the shoulder, you can use our website to look up MRI scan costs.

Have you had a Shoulder MRI scan? What was it like? Please leave your comments below.

The FDA recently released a warning regarding wearing a medicated patch during MRI. Some transdermal medication patches contain metal which can be heated by MRI and cause skin burns under and around the patch. Although most patches do have MRI safety warnings, the FDA recently discovered that several manufacturers did not have adequate labeling. The safety advisory applies to over the counter and prescribed medicated patches, including nicotine patches.

The FDA also recommended that patients:

• inform their doctor ordering the MRI of their patches
• inform the MRI scan center staff
• mark on the MRI screening form that a patch is being used

You can watch the FDA's advisory below and read more about MRI and metal.