Determination of organ absorbed doses in patients following bone scan with using of MIRD method

Bone scintigraphy is the most commonly performed procedure in nuclear medicine departments. Radiation risk estimates and optimal use of various radiodiagnostic techniques require accurate dosimetry for representative groups of patients. The aim of the present study was to determination of organ absorbed doses in patients following bone scan with using of MIRD method. In this study، each patient was injected 25 mCi of mTc-MDP99. Patients were imaged with a gamma camera. Whole-body images from patients were acquired at 10، 60، 90، 180 minutes after mTc-MDP99 injection. Regions of interest (ROIs) were drawn around organs for count per minute calculation. Count per minute was converted to activity using the conjugate view counting method. The mean uptake activity was measured in different time periods after injection of mTc-MDP99 for each organ. The absorbed doses per unit injected activity (mrad/mCi) for liver، bladder، spleen، right and left kidney were 7. 78، 8. 17، 7. 96، 30. 0 and 30. 9 mrad/mCi، respectively. In this study the kidneys and liver received maximum and minimum absorbed doses، respectively. These results were consistent with other studies.