title: Comparison of Tl-201 renal uptake with Tc-99m DTPA angiorenography in patients with hypertension. Measures of renal asymmetry.
abstract: Renal uptake of Tl-201 reflects renal perfusion and may have a role in defining renal asymmetry in patients with hypertension who are referred for myocardial scintigraphy. The authors compared two methods of quantitating differential renal uptake of Tl-201, with similar data obtained from the angiographic and renal uptake (RU) phases of Tc-99m DTPA scintigraphy in 35 patients with hypertension. For Tl-201, asymmetry in renal counts was quantitated based on a simple outline technique or on interpolative background subtraction of 5-minute posterior images. Inter-observer and intra-observer variability among duplicate measurements were lower for Tl-201, particularly with interpolative background subtraction, than for Tc-99m DTPA. Renal/background ratios were similar for Tl-201 and RU-phase Tc-99m DTPA images when considering liver, spleen, or inter-renal regions as background; however, paraspinal uptake was relatively higher with Tl-201 (P less than 0.01). Qualitatively, renal asymmetry scores with the two radiotracers agreed (r = 0.89, blinded readings by four observers), although asymmetry was more marked with Tl-201 (P = 0.06). Measurements with Tl-201 agreed with both phases of Tc-99m DTPA (r = 0.96 to 0.98), but interpolative background subtraction systematically yielded greater inter-renal asymmetry than RU (P less than 0.01), reflecting the qualitative impression. Thus, ancillary Tl-201 imaging reflects differences between the kidneys in a fashion similar but not identical to Tc-99m DTPA scintigraphy.
authors.affiliation: Department of Diagnostic Radiology/Nuclear Medicine, University of Western Ontario, London, Canada.
authors.forename: G A
authors.initials: GA
authors.lastname: Hurwitz
authors.forename: J E
authors.initials: JE
authors.lastname: Powe
authors.forename: C A
authors.initials: CA
authors.lastname: Wesolowski
authors.forename: A G
authors.initials: AG
authors.lastname: Mattar
mesh_terms: D015901:Angiography, Digital Subtraction; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D006978:Hypertension, Renovascular / Q000000981:diagnostic imaging*; D007668:Kidney / Q000000981:diagnostic imaging*; D011866:Radioisotope Renography / Q000379:methods; D016284:Technetium Tc 99m Pentetate; D013794:Thallium Radioisotopes
chemical_list: D013794:Thallium Radioisotopes; D016284:Technetium Tc 99m Pentetate