AUTOMATIC PREPARATION OF RADIOPHARMACOKINETIC DATA FOR IN-VIVO ESTIMATION OF RECEPTOR BIOCHEMISTRY

We present a fully automated region of interest (ROI) and motion corre ction program for the generation of heart and liver time-activity data resulting from a hepatic functional imaging study using [Tc-99m]galac tosyl-neoglycoalbumin Tc-99m-NGA), Methods: The program automatically draws heart and liver ROI and corrects for lateral movement of the sub ject. Eighty-four Tc-99m-NGA studies, consisting of 32 healthy subject s and 52 patients with liver disease, were processed and submitted to an automated kinetic analysis that estimates the subject's asialoglyco protein receptor concentration [R](0). Results: When compared to time- activity data generated by operator-drawn ROIs without motion correcti on, the average reduced Chi-square of the kinetic analysis decreased s ignificantly (p < 0.001) from 2.20 to 1.37 and the number of studies t hat satisfied quality control increased from 74 to 81 studies, Receive r operating characteristic of [R](0) resulted in greater detectability (0.984 +/- 0.012 compared with 0.965 +/- 0.020) when automatic ROI ge neration was employed, Using the test criteria of 0.65 mu M, the sensi tivity of [R](0) increased from 0.88 to 0.92 and the specificity incre ased from 0.96 to 0.97. Conclusion: Automated definition of liver and heart ROIs with motion correction, that reduces observational noise, i ncreased the success rate of the radiopharmacokinetic analysis from 88 % to 96%.