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Free mebrofenin clearance
J Anthony Parker1, Muhammad M Tahir, Suzanne R Whitmarsh
1Nuclear Medicine and Interventional Radiology, Department of Radiology, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
Objectives:
To determine if three new simplified equations for measurement of free mebrofenin clearance give similar results to the equations defined by Ekman et. al ., and to evaluate the properties of all four methods. Regional mebrofenin clearance has been used to predict future remnant liver function and liver failure after regional liver therapy, such as partial hepatic resection.
Methods:
The means, standard deviations, and correlations of the free mebrofenin clearance measured by the Ekman method and the three simplified methods were compared in a consecutive series of 26 studies in 20 patients. The fractional change in the blood and free mebrofenin activities were compared, and integrals of normalized blood and free mebrofenin ("effective times") were compared.
Results:
The average percent free mebrofenin clearance for the Ekman and the first, second and third simplified methods were 13.62 ± 2.88%/min, 12.98 ± 2.97%/min, 12.52 ± 2.81%/min and 15.03 ± 2.27%/min, respectively. The correlations of the new methods with Ekman were 0.97, 0.93 and 0.93. The fractional changes during the measurement interval for the blood and free mebrofenin activities were 0.381 ± 0.065 and 0.329 ± 0.062, difference 0.052, P < 0.5. The integrals of normalized blood and free mebrofenin activities were 2.566 ± 0.160 min and 2.661 ± 0.158 min, difference of 0.094 min and P < 0.05.
Conclusions:
The results of the three new methods were similar to the Ekman method. The first simplified method was identified as the lead method for clinical validation in a larger population.
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