Magnetic Resonance Imaging for Evaluating Kidney Function

Healthy Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00006173
• Other study ID #: 000195
• Secondary ID: 00-CC-0195
• Status: Completed
• Phase: N/A
• First received: August 11, 2000
• Last updated: March 3, 2008
• Start date: August 2000
• Est. completion date: January 2004

Study information

• Verified date: January 2004
• Source: National Institutes of Health Clinical Center (CC)
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Observational

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 40
• Est. completion date: January 2004
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: N/A and older

Eligibility

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 Design

N/A

Related Conditions & MeSH terms

• Healthy
• Hypertension
• Hypertension, Renovascular
• Renovascular Hypertension

Locations

Country	Name	City	State
United States	Warren G. Magnuson Clinical Center (CC)	Bethesda	Maryland

Sponsors (1)

Lead Sponsor	Collaborator
National Institutes of Health Clinical Center (CC)

Country where clinical trial is conducted

United States, 

References & Publications (3)

Bouyounes BT, Libertino JA. Renovascular hypertension. Curr Opin Urol. 1999 Mar;9(2):111-4. Review. — View Citation

Kulkarni S, O'Farrell I, Erasi M, Kochar MS. Stress and hypertension. WMJ. 1998 Dec;97(11):34-8. Review. — View Citation

Taylor A. Radionuclide renography: a personal approach. Semin Nucl Med. 1999 Apr;29(2):102-27. Review. — View Citation