title: Renal transplant pyelocaliectasis: role of duplex Doppler US in evaluation.
abstract: To distinguish the obstructed from the nonobstructed dilated collecting system of transplanted kidneys without interventional diagnostic measures, the authors prospectively evaluated duplex Doppler analysis (determination of resistive index [RI]) in 35 renal transplant patients with pyelocaliectasis. Proof of the presence or absence of obstruction was obtained at interventional procedures in 18 patients and at clinical follow-up in 17. Thirteen kidneys were obstructed (mean RI, .81 +/- .06), while 22 had nonobstructive dilatation (mean RI, .66 +/- .07). The RI difference was statistically significant (P less than or equal to .01). Of 21 kidneys with a normal RI, only two had obstruction. In both of these, the obstruction was associated with a significant peritransplant collection of fluid due to a ureteral leak. In the seven obstructed transplanted kidneys with follow-up, the mean RI was .82 +/- .06 before nephrostomy and .67 +/- .05 after nephrostomy. Obstruction was a common cause of an elevated RI (greater than or equal to .75). Other causes of transplant dysfunction can be associated with an elevated RI and nonobstructed dilatation. More important, a normal RI should strongly argue against obstruction unless a ureteral leak is also present.
authors.affiliation: Department of Radiology, University of Michigan Hospitals, Ann Arbor 48109-0030.
authors.forename: J F
authors.initials: JF
authors.lastname: Platt
authors.forename: J H
authors.initials: JH
authors.lastname: Ellis
authors.forename: J M
authors.initials: JM
authors.lastname: Rubin
mesh_terms: D000328:Adult; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging*; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D016030:Kidney Transplantation; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011446:Prospective Studies; D014463:Ultrasonography; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D014563:Urodynamics