Abstract
Objectives
The aim of this study was to determine the time-activity curve in the cardiac and hepatic region by99mTc-GSA dynamic SPECT which is clinically used in liver scintigraphy and evaluate the temporal changes in the consistency and errors at the absolute scale using the regression equation of changes in the blood concentration of99mTc-GSA.
Methods
In 11 patients who underwent99mTc-GSA dynamic SPECT over the 30 min period after IV injection, the percentages of activity in the collected blood and in the blood pool estimated by dynamic SPECT were determined as the plasma clearance by blood collection and as the blood clearance by cardiac pooling. Extrahepatic uptake, expressesd as 100 - (% uptake in the liver by dynamic SPECT (%)) was calculated as the blood clearance by the liver. The regression equation(Y = Yo + Aeat was determined from the changes in the counts, expressed as a percent. Percent errors and the differences in theY-intercept (Yo), coefficient(A) and slope (α) on the regression curve were compared.
Results
Blood pool clearance gradually exceeded the measured plasma clearance. The clearance by the liver started from a very low initial value and gradually became equal to that of plasma clearance over the first 15 minutes and exceeded it over the second 15 minutes. TheY-intercept was significantly higher in the blood pool clearance than that in the measured plasma clearance (p < 0.001), and the coefficient was significantly lower in the former than the latter (p < 0.001). The coefficient and slope were significantly lower in the hepatic clearance than the plasma clearance (p < 0.001, p < 0.005).
Conclusion
The time-activity curve of the blood pool showed a tendency towards overestimation in the second half of the examination, probably due to scatter effect from the liver. The time-activity curve of liver uptake showed a tendency towards overestimation in the first half of the examination, probably due to the high concentration in the hepatic blood pool, and underestimation in the second half.
Similar content being viewed by others
References
Morell AG, Gregoriadis G, Scheinberg IH, Hickman J, Ashwell G. The role of sialic acid in determining the survival of glycoproteins in the circulation.J Biol Chem 1971; 246:1461–1467.
Ashwell G, Morell AG. The role of surface carbohydrates in the rat hepatic recognition and transport of circulating glycoprotein.Adv Enzymol 1974; 41:99–128.
Stowell CP, Lee YC. Neoglycoproteins. The preparation and application of synthetic glycoproteins.Adv in carbohydr Chem Biochem 1980; 37:225–281.
Stadalnik RC, Vera DR, Woodle ES, Trudeau WL, Porter BA, Ward RE et al. Technetium-99m NGA functional hepatic imaging: preliminary clinical experience.J Nucl Med 1985; 26:1233–1242.
Galli G, Maini CL, Orlando P, Cobelli C, Thomaset K, Deleide G, et al. A radiopharmaceutical for the study of the liver:99mTc-DTPA-asialo-orosomucoid II: Human dynamic and imaging studies.J Nucl Med Allied Sci 1988; 32:117–126.
Kubota Y, Kitagawa S, Inoue K, Ha-Kawa SK, Kojima M, Tanaka Y. Hepatic functional scintigraphic imaging with99mTechnetium galactosyl serum albumin.Hepatogastroenterol 1993; 40:32–36.
Kudo M, Vera DR, Stadalnik RC, Trudeau WL, Ikekubo K, Todo A.In vivo estimates of hepatic binding protein concentration: Correlation with classical indicators of hepatic function reserve.Am J Gastroenterol 1990; 85:1142–1148.
Kudo M, Todo A, Ikekubo K, Hino M, Yonekura Y, Yamamoto K, et al. Functional hepatic imaging with receptor-binding radiopharmaceutical: clinical potential as a measure of functioning hepatocyte mass.Gastroenterol Jpn 1991; 26:734–741.
Koizumi K, Uchiyama G, Arai T, Ainoda T, Yoda Y. A new liver functional study using Tc-99m DTPA-galactosyl human serum albumin: Evaluation of the viability of several functional parameters.Ann Nucl Med 1992; 6:83–87.
Bossuyt A, De Geeter F, Jacobs A, Camus M, Thornback JR. Initial clinical experience with a new kit formulation of Tc-99m-galactosylated albumin for functional hepatic imaging.Nucl Med Commun 1990; 11:469–475.
Vera DR, Stadalnik RC, Trudeau WL, Scheibe PO, Krohn KA. Measurement of receptor concentration and forward-binding rate constant via radiopharmacokinetic modeling of technetium-99m-galactosyl-neoglycoalbumin.J Nucl Med 199l;32:1169–1176.
Ha-Kawa SK, Tanaka Y. A quantitative model of techne-tium-99m DTPA-galactosyl-HSA for the assessment of hepatic blood flow and hepatic binding receptor.J Nucl Med 1991; 32:2233–2240.
Sugai Y, Komatani A, Hosoya T, Takahashi K. Analysis of the early blood kinetics of99mTc-GSA and its verification: new one-compartment model and regression equation.Nucl Med Commun 2001; 22:773–778.
Torizuka K, Ha-Kawa SK, Ikekubo K, Suga Y, Tanaka Y, Hino M, et al. Phase I Clinical Study on99mTc-GSA, a New Agent for Functional Imaging of the Liver.KAKU IGAKU (Jpn J Nucl Med) 1991; 28:1321–1331.
Hwang EH.99mTc-GSA Dynamic SPECT for Regional Hepatic Functional Reserve Estimation: Assessment of Quantification.KAKU IGAKU (Jpn J Nucl Med) 1999; 36:315–322.
Ha-Kawa SK, Suga Y, Kouda K, Ikeda K, Tanaka Y. Validation of curve-fitting method for blood retension of99mTc-GSA: Comparison with blood sampling method.Ann Nucl Med 1997; 11:15–20.
Jaszczak RJ, Greer KL, Floid CE, Harris CC, Coleman RE. Improved SPECT quantitation using compensation for scattered photons.J Nucl Med 1984; 25: 893–900.
Ichihara T, Maeda H, Yamakado K, Motomura N, Matsumura K, Takeda K, et al. Quantitative analysis of scatter- and attenuation-compensated dynamic single-photon emission tomography for functional hepatic imaging with a receptor-binding radiopharmaceutical.Eur J Nucl Med 1996; 24:59–67.
Sugai Y, Komatani A, Hosoya T, Yamaguchi K. Response to Percutaneous Transhepatic Portal Embolization: Evaluation of New Proposed Parameters by99mTc-GSA SPECT in Prognostic Estimation following Hepatectomy.J Nucl Med 2000; 41:421–425.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Sugai, Y., Komatani, A., Hosoya, T. et al. Comparisons of the time-activity curves of the cardiac blood pool and liver uptake by99mTc-GSA dynamic SPECT and measured99mTc-GSA blood concentrations. Ann Nucl Med 20, 295–301 (2006). https://doi.org/10.1007/BF02984646
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02984646