Influence of Iodinated Contrast Media and Paramagnetic Contrast Media on Changes in Uptake Counts of^99mTc

The purpose of this study is to figure out how uptake counts of technetium ($^99mTc$) among radioisotopes in the human body are affected if computed tomography (CT), magnetic resonance imaging (MRI) and isotope examination are performed consecutively. $^99mTc$ isotope material, iodinated contrast media for CT and paramagnetic contrast media for magnetic resonance (MR) were used as experimental materials. First, $^99mTc$ was added to 4 cc normal saline in a test tube. Then, 2 cc of CT contrast media such as $Iopamidol^(R)$ and $Dotarem^(R)$ were diluted with 2 cc normal saline, and 2cc of MRI contrast media such as $Primovist^(R)$ and $Gadovist^(R)$ were diluted with 2 cc normal saline. Each distributed contrast media was a total of 4 cc and included 10m Ci of $^99mTc$. A gamma camera, a LEHR (Low energy high resolution) collimator and a pin-hole collimator were used for image acquisition. Image acquisition was repeated a total of 6 times and 120 frames were obtained and uptake counts of $^99mTc$ were measured (from this procedure). In this study, as a result of measuring the uptake counts of $^99mTc$ using the LEHR collimator, the uptake counts were less measured in all contrast media than normal saline as a reference. In particular, the lowest uptake counts were measured when $Gadovist^(R)$, contrast media for MRI, was used. However, the result of measuring the uptake counts of $^99mTc$ using the pin-hole collimator showed higher uptake counts in all contrast media, except for $Iopamidol^(R)$, than normal saline as a reference. The highest uptake counts were measured particularly when $Primovist^(R)$, contrast media for MRI, was used. In performing the gamma camera examination using contrast media and $^99mTc$, it is considered significant to check the changes in the uptake counts to improve various diagnosis values.