A dynamic phantom for radionuclide renography.
The aim of the study was to develop and test a dynamic phantom simulating radionuclide renography. The phantom consisted of five partly lead covered plastic containers simulating kidneys, heart, bladder and background (soft tissues, liver and spleen). Dynamics were performed with multiple movable steel plates between containers and a gamma camera. Control of the plates is performed manually with a stopwatch following exact time schedules. The containers were filled with activities (99mTc) which produce count rates close to clinical situations. Count rates produced by the phantom were compared with ten clinical renography cases: five 99mTc MAG3 and five 99mTc DTPA examinations. Two phantom simulations were repeated three times with separate fillings, acquisitions and analyses. Precision errors as a coefficient of variation (CV) of repeated measurements were calculated and theoretical values were compared with the corresponding measured ones. A multicentre comparison was made between 19 nuclear medicine laboratories and three clinical cases were simulated with the phantom. Correlations between count rates produced by the phantom and clinical studies were r = 0.964 for 99mTc MAG3 (p < 0.001) and 0.961 for 99mTc DTPA (p < 0.001). The precision error was 4.5 +/- 3.2% and the percentage difference between theoretical and measured values for Tmax was 4.0 +/- 1.6%. Images and curves of the scanned phantom were close to a real patient in all 19 laboratories but calculated parameters varied: the difference between theoretical and measured values for Tmax was 6.8 +/- 6.2%. The difference between laboratories is most probably due to variations in acquisition protocols and analysis programs: 19 laboratories with 18 different protocols and 8 different programs. The dynamics were found to be repeatable and suitable for calibration purposes for radionuclide renography programs and protocols as well as for multicentre comparisons.
Heikkinen
J O
JO
Department of Nuclear Medicine, Etelä-Savo Hospital District, Mikkeli Central Hospital, Finland. jari.heikkinen@esshp.fi
D005387:Finland; D015902:Gamma Cameras; D006321:Heart / Q000000981:diagnostic imaging; D007668:Kidney / Q000000981:diagnostic imaging; D008099:Liver / Q000000981:diagnostic imaging; D015337:Multicenter Studies as Topic; D019047:Phantoms, Imaging; D011866:Radioisotope Renography / Q000295:instrumentation / Q000379:methods*; D011877:Radionuclide Imaging / Q000379:methods*; D015203:Reproducibility of Results; D017263:Technetium Tc 99m Mertiatide / Q000737:chemistry; D016284:Technetium Tc 99m Pentetate / Q000737:chemistry; D014513:Ureter / Q000000981:diagnostic imaging
D017263:Technetium Tc 99m Mertiatide; D016284:Technetium Tc 99m Pentetate