Magnetic Resonance Imaging for Evaluating Kidney Function

March 3, 2008 updated by: National Institutes of Health Clinical Center (CC)

Assessment of Renal Artery Stenosis and Renovascular Hypertension by Contrast Enhanced Magnetic Resonance Imaging: A Pilot Study

Renovascular hypertension (RVH) is a potentially curable disease affecting 0.5-5 percent of patients with hypertension. The current diagnostic work-up of RVH involves a complex algorithm which includes doppler ultrasound, captopril renography and conventional angiography. Because of the expense, risk and inconvenience of this workup, patients may not be correctly diagnosed.

Advances in MR technology present the opportunity to develop a single comprehensive test. This would combine an MR angiogram that provides anatomic information about the renal arteries, and an MR renogram that provides information about the functional impact of a stenosis as a cause of hypertension. Our main purpose is to test MR renography with and without an oral angiotensin converting enzyme inhibitor (ACEI) combined with MR angiography against the reference standard of captopril radionuclide renography. Secondary goals of this study are to test whether hypoxia within ischemic kidneys affected by RVH is detectable by T2 weighted (Blood oxygen level dependent or BOLD) MRI. This is considered of value since such a test of oxygenation would further shorten and simplify the diagnostic MR test. Information gained from this study could lead to important changes in the diagnostic and pathophysiologic understanding of RVH.

Study Overview

Status

Completed

Conditions

Detailed Description

Renovascular hypertension (RVH) is a potentially curable disease affecting 0.5-5% of patients with hypertension. The current diagnostic work-up of RVH involves a complex algorithm which includes doppler ultrasound, captopril renography and conventional angiography. Because of the expense, risk and inconvenience of this workup, patients may not be correctly diagnosed.

Advances in MR technology present the opportunity to develop a single comprehensive test. This would combine an MR angiogram that provides anatomic information about the renal arteries, and an MR renogram that provides information about the functional impact of a stenosis as a cause of hypertension. Our main purpose is to test MR renography with and without an oral angiotensin converting enzyme inhibitor (ACEI) combined with MR angiography against the reference standard of captopril radionuclide renography. Secondary goals of this study are to test whether hypoxia within ischemic kidneys affected by RVH is detectable by T2* weighted (Blood oxygen level dependent or BOLD) MRI. This is considered of value since such a test of oxygenation would further shorten and simplify the diagnostic MR test. Information gained from this study could lead to important changes in the diagnosis and pathophysiologic understanding of RVH.

Study Type

Observational

Enrollment

40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • Warren G. Magnuson Clinical Center (CC)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • ADULT
  • OLDER_ADULT
  • CHILD

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

INCLUSION CRITERIA

Healthy volunteers or patients with significant clinical suspicion of renovascular hypertension.

Subjects able to understand the informed consent for this study.

Subjects must be able to hold their breath for 20 second intervals.

Patients must be clinically stable and be judged by their physician able to tolerate the MR study of 1.5-2 hour duration.

EXCLUSION CRITERIA

Any contraindication for MR study including: pacemaker or other implanted electronic device; cochlear implants; metal in the eye; embedded shrapnel fragments; cerebral aneurysm clips; or medical infusion pumps.

Allergy to gadolinium, iodinated contrast media, ACEIs, or sulphur-containing medication.

Patients have a hematocrit at or below 30. Severe anemia may predispose to hypotension after captopril.

Patients with hyperkalemia (plasma potassium: above 5.0 mmol/L), because of the risk of arrhythmia.

Clinically unstable patients and those unable to tolerate a 1-2 hour MR study. Examples of medical conditions that would lead to exclusion include unstable angina, dyspnea at rest, severe pain at rest, or severe back pain.

Pregnancy.

Nursing mothers.

Subjects who are claustrophobic and are unable to tolerate MR imaging.

Patients with a serum creatinine concentration above 4mg/dl.

Bilateral renal stents.

Healthy subjects must not have an abnormality detected on dipstick urinalysis, or a systolic BP above 140 mmHg or a diastolic BP above 90 mmHg on screening examination or an abnormal BUN or creatinine level in the blood.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Institutes of Health Clinical Center (CC)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2000

Study Completion

January 1, 2004

Study Registration Dates

First Submitted

August 11, 2000

First Submitted That Met QC Criteria

August 11, 2000

First Posted (ESTIMATE)

August 14, 2000

Study Record Updates

Last Update Posted (ESTIMATE)

March 4, 2008

Last Update Submitted That Met QC Criteria

March 3, 2008

Last Verified

January 1, 2004

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 000195
  • 00-CC-0195

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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