Formula for Volume

Volume (mL) =        activity needed (mCi)

                                        concentration available (mCi/mL

Formula for Concentration

Concentration (mCi/ml) = Activity (mCi)

                                   Volume (mL)

Formula to calculate % error

Expected-Actual  x 100%

Expected           

Diluation ratio 1:15, concentration 20 mCi/mL

20 x 1 = 20 mCi

     1 x 15 = 15 mL       

20mCi/15 mL = 1.33 mCi/mL

Formula for Effective Half Life

EFFECTIVE HALF LIFE =

Physical x Biological

Physical + Biological

Pixel size formula

distance (mm)

# of Pixels

Ex:  350 mm

       128x128

350 = 2.7 pixel size

128                      

CORRECTION FACTOR =

expected activity

actual measured activity

% Uptake Formula (Thyroid)

Thyroid counts-thigh counts

(capsule counts-background) (decay factor) x 100

Formula for Activity

Activity = Concentration x Volume