Gamma camera determination of thyroid mass

A method is suggested for imaging of the thyroid area as a zone of interest and determination of the number of elements of the matrix (the pixels) upon which the image is built. The value of each pixel in square centimeters for different martices and image densities is obtained by preliminary calibration and placing at an exactly determined distance (20 cm apart) two syringes with 1,75 MBq 99mTc-pertechnetate activity each. Knowing the distance between the two radioactive sources, one readily estimates the calibration coefficient. The surface value, obtained directly in the zone of interest, multiplied by the calibration coefficient, is expressed in square centimeters. Once the surface of the thyroid has been determined, its mass is readily estimated. Results are presented in 9 tables allowing to define the thyroid mass at different matrices and magnifications by the number of pixels