These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Technetium-99m hexakis 2-methoxy-2-isobutyl isonitrile and thallium-201 extraction, washout, and retention at varying coronary flow rates in rabbit heart.
    Author: Marshall RC, Leidholdt EM, Zhang DY, Barnett CA.
    Journal: Circulation; 1990 Sep; 82(3):998-1007. PubMed ID: 2394016.
    Abstract:
    Technetium-99m hexakis 2-methoxy-2-isobutyl isonitrile (Tc-MIBI) and thallium-201 extraction, washout, and retention were investigated and compared in 20 isolated, isovolumic, retrograde blood-perfused rabbit hearts at flow rates ranging from 0.5 to 3.5 ml/g wet wt min-1 in the absence of tracer recirculation. Mean Tc-MIBI peak instantaneous extraction was lower (0.55 +/- 0.10, p less than 0.001) and more affected by flow rate (p less than 0.05) than 201Tl peak instantaneous extraction (0.83 +/- 0.06). In contrast, the rate of 201Tl washout was significantly faster (p less than 0.05) and initially more dependent on perfusion rate (p less than 0.05) than Tc-MIBI washout. Reflecting its higher peak instantaneous extraction, 201Tl retention was 55-79% higher immediately after isotope injection (p less than 0.001) than Tc-MIBI retention, and relative changes in maximal 201Tl net uptake correlated better (p less than 0.05) with relative flow changes than maximal Tc-MIBI net uptake. However, due to its faster washout rate, the superiority of thallium over Tc-MIBI as a perfusion indicator was lost within 10 minutes of tracer injection under the present single-pass experimental conditions. These data were interpreted to indicate that 1) Tc-MIBI is not as well extracted and has a slower washout rate than 201Tl; 2) varying the coronary flow rate has significant but divergent effects on the extraction, washout, and retention of Tc-MIBI and 201Tl; and 3) the present results support continued evaluation of Tc-MIBI as a possible perfusion indicator.
    [Abstract] [Full Text] [Related] [New Search]