Mayo Clinic Researchers Among First To Use "Fast CT" To See Human Kidney Function

According to Mayo Clinic physiologist Juan C. Romero, M.D., this novel technique will prove very useful in the diagnosis and evaluation of kidney disease in general, and in kidney-related hypertension in particular. Kidneys, which separate nutrients from waste, are important in regulating blood pressure; conversely, blood pressure is important to proper kidney function. And the ability to identify malfunctioning kidneys may help direct proper prevention and therapy in patients with kidney disease, according to Dr. Romero.

Fast computed tomography - or CT scanners such as electron beam CT - now enables detailed observation of the kidney's subtle functions such as blood flow and filtration. Fast CT scans are non-invasive and painless. Patients lie on a table while X-ray beams scan portions of the body. The scanner takes a rapid succession of images that may be viewed alone or in sequence.

The CT's ability to digitize and sequence images helps physicians see and analyze blood flowing through both kidneys, different areas within kidneys, how much blood is filtered to form urine, and the urine formation process, according to Dr. Romero.

"We can even locate problems and potentially diagnose kidney disease before symptoms appear" says Dr. Romero, whose recent findings on this subject were published in the September issue of Seminars in Nephrology.

"Now, for the first time, we also may be able to see which kidney is impaired," Dr. Romero adds. "Previously, individual kidney function was impossible to evaluate non-invasively."

Mayo researchers performed early studies using Fast CT in animals and later in humans. Through a grant from the National Institutes of Health, additional study in human patients begins this month at Mayo Clinic. The study will focus on individual kidney function in situations of impaired blood flow.

Dr. Romero says that Fast CT has the potential to eliminate up to half of conventional kidney-related laboratory tests, in addition to expediting a patient's time spent being evaluated and waiting for results by two to five days. The full potential of this technique will not be known until further evaluation in patients, he adds.