THE KIDNEYS AND HYPERTENSION
Guest Editor: Blaufox M. D. 

The Quarterly Journal of Nuclear Medicine 2002 December;46(4):268-82

Copyright © 2009 EDIZIONI MINERVA MEDICA

language: English

Renovascular hypertension: nuclear medicine techniques

Taylor A.

Department of Radiology Emory University School of Medicine, Atlanta, GA, USA

Angiotensin con­vert­ing ­enzyme inhi­bi­tion (­ACEI) renog­ra­phy is the ­only imag­ing exam­ina­tion ­that ­tests direct­ly for the pres­ence of ren­o­vas­cu­lar hyper­ten­sion (RVH); oth­er imag­ing exam­ina­tions ­test for the pres­ence of ­renal ­artery sten­o­sis (RAS). The ­goals of ­ACEI renog­ra­phy are two-­fold: 1) to ­detect ­those ­patients ­with hyper­ten­sion who ­have ­renal ­artery sten­o­sis as the ­cause of ­their hyper­ten­sion and who ­would ben­e­fit ­from revas­cu­lar­iza­tion, and 2) to deter­mine ­which hyper­ten­sive ­patients do not ­have ren­o­vas­cu­lar hyper­ten­sion and obvi­ate the ­expense and ­risk of angio­gra­phy and, poten­tial­ly, revas­cu­lar­iza­tion. This ­review sum­mariz­es gen­er­al com­po­nents of ­renal scin­tig­ra­phy (pretest void­ing, hydra­tion, ­patient posi­tion, rel­a­tive ­uptake, ­time to ­peak ­height of the reno­gram ­curve, 20 min/max ­ratio, post­void imag­es, qual­ity con­trol) as ­well as ­those com­po­nents spe­cif­ic to ­ACEI renog­ra­phy (­choice of radio­phar­ma­ceu­ti­cal, ­choice of ACE inhib­i­tor, angio­ten­sin II recep­tor block­ers, diu­ret­ics, paren­chy­mal ­mean tran­sit ­time, mon­i­tor­ing of ­blood pres­sure, 1 ver­sus 2 day pro­to­cols and omis­sion of the base­line ­study). ­ACEI renog­ra­phy is high­ly accu­rate in ­patients ­with sus­pect­ed RVH who ­have nor­mal or ­near nor­mal ­renal func­tion. In ­this ­patient pop­u­la­tion, the sen­si­tiv­ity and spec­i­fic­ity of ­ACEI renog­ra­phy for ren­o­vas­cu­lar hyper­ten­sion ­exceed 90%; angio­gra­phy as an ­initial ­approach is not ­cost effec­tive. Data ­from 10 stud­ies eval­u­at­ing ­cure or improve­ment in ­blood pres­sure in 291 ­patients under­go­ing revas­cu­lar­iza­tion ­showed the ­mean pos­i­tive pre­dic­tive val­ue of ­ACEI renog­ra­phy to be 92%. When azo­tem­ic ­patients ­present ­with sus­pect­ed RVH, as ­many as 50% of ­patients may ­have an inter­me­di­ate prob­abil­ity ­ACEI reno­gram and the sen­si­tiv­ity of detect­ing RVH ­falls to approx­i­mate­ly 80% ­even ­when inter­me­di­ate and ­high prob­abil­ity ­tests are com­bined.