title: The use of colorflow duplex scanning to detect significant renal artery stenosis.
abstract: The purpose of this study was to review our institutional experience with colorflow duplex scanning in detecting significant renal artery stenosis and to validate the criteria used: renal artery peak systolic velocity (PSV) >/=200 cm/sec and renal-to-aortic peak systolic ratio (RAR) >/=3.5. The results of renal artery duplex and arteriography in 58 patients (107 kidneys) who underwent both exams were reviewed. Arteriography revealed 32 main renal arteries with >/=60% stenosis. The PSV criterion detected 29, for a sensitivity of 91%, specificity of 75%, positive predictive value (PPV) of 60%, negative predictive value (NPV) of 95%, and accuracy of 79%. Using RAR >/=3.5 provided a sensitivity of 72%, specificity of 92%, PPV of 79%, NPV of 88%, and accuracy of 86%. In a subset of 36 kidneys that had hilar scans, the criteria of acceleration time (AT) >/=100 cm/sec and index (AI) </=3.78 kHz/sec were evaluated. The AT and AI yielded sensitivity of 50% and 36%, specificity of 86% and 100%, PPV of 70% and 100%, NPV of 73% and 71%, and accuracy of 72% and 75%, respectively. Colorflow duplex scanning is clinically useful in screening for hemodynamically significant renal artery stenosis. The renal artery PSV criterion is highly sensitive, with a high NPV that obviates the need for arteriography in most cases of a negative duplex. The criteria of RAR, AT, and AI are of less value.
authors.affiliation: Department of Surgery, Division of Vascular Surgery, University of Southern California, School of Medicine, Los Angeles, CA, USA.
authors.forename: H T
authors.initials: HT
authors.lastname: Hua
authors.forename: D B
authors.initials: DB
authors.lastname: Hood
authors.forename: C C
authors.initials: CC
authors.lastname: Jensen
authors.forename: S E
authors.initials: SE
authors.lastname: Hanks
authors.forename: F A
authors.initials: FA
authors.lastname: Weaver
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012078:Renal Artery Obstruction / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D018616:Ultrasonography, Doppler, Duplex