Finding the right tests…
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Finding the right tests…
MRI
MRI RENAL ANGIOGRAPHY images the arteries that carry blood to your kidneys, checking for narrowing known as renal artery stenosis. This narrowing is a real, documented cause of high blood pressure, called renovascular hypertension, because a kidney that senses reduced blood flow releases hormones that raise blood pressure throughout the body. It's also used to assess kidney arteries before certain treatments, such as evaluating a donor kidney or planning a stent. Because people being checked for kidney artery problems sometimes already have reduced kidney function, this scan can often be done using techniques that skip the injected gadolinium dye altogether, relying instead on blood flow itself to create contrast, which avoids a rare but serious kidney-related reaction to the dye.
This scan checks the renal arteries for narrowing, blockage, or unusual branching, comparing blood flow on each side. Because narrowing here can affect both blood pressure and kidney function, your doctor reads it alongside blood pressure readings and kidney function tests rather than as a stand-alone answer.
Renal artery stenosis means one or both of the arteries feeding your kidneys have narrowed, usually from plaque buildup or, less often, a condition called fibromuscular dysplasia that mostly affects younger people. When a kidney senses less blood coming in, it responds as if your whole body's blood pressure were too low and releases hormones that make blood vessels constrict and the body hold onto salt and water, which raises blood pressure well beyond the kidney itself.
Left narrow for long enough, reduced blood flow can also gradually reduce how well a kidney works. That combination, high blood pressure that doesn't respond well to usual medication plus declining kidney function, is often what makes a doctor order this scan rather than treat blood pressure alone.
Gadolinium dye is cleared through the kidneys, and in people with significantly reduced kidney function it carries a small risk of a serious complication. Because kidney artery imaging often involves exactly these patients, non-contrast MRA techniques that use blood flow itself as the image source are frequently used instead, avoiding the dye without giving up image quality for many patients. Whether contrast is needed for your particular scan is a decision your doctor and the radiology team make together.
This scan doesn't replace blood pressure or kidney function monitoring. Your doctor uses it to decide whether the narrowing found is significant enough to treat.
It's a narrowing of one or both arteries that carry blood to your kidneys, usually from plaque buildup or, less often, a condition called fibromuscular dysplasia. This scan is built to detect that narrowing directly.
It can help. Renal artery stenosis is a documented cause of high blood pressure that doesn't always respond well to usual medication, so your doctor may order this scan when that combination shows up alongside declining kidney function.
Not always. Because people having their kidney arteries checked sometimes already have reduced kidney function, techniques that skip the injected gadolinium dye are often used instead, though your doctor decides based on your situation.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
Non-contrast versions of this scan are often chosen for exactly this reason, since gadolinium dye is cleared through the kidneys and carries added risk when kidney function is significantly reduced. Tell your doctor about any kidney problems before booking.
This scan is built specifically around the renal arteries feeding your kidneys, rather than following a general request for an unnamed vessel group. It's ordered when a kidney-specific vascular problem is already suspected.
Yes, both renal arteries are typically imaged in the same scan, so your doctor can compare blood flow to each kidney side by side.
Not necessarily. Your doctor weighs the scan findings alongside your blood pressure readings and kidney function before deciding whether treatment, including a possible stent, is needed.