investigation of collimator influential parameter on spect image quality: a monte carlo study

background: obtaining high quality images in single photon emission tomography (spect) device  is the most important goal in nuclear medicine. because if image quality is low, the possibility of making a mistake in diagnosing and treating the patient will rise. studying effective factors in spatial resolution of imaging systems is thus deemed to be vital. one of the most important factors in spect imaging in nuclear medicine is the use of an appropriate collimator for a certain radiopharmaceutical feature in order to create the best image as it can be effective in the quantity of full width at half maximum (fwhm) which is the main parameter  in spatial resolution. method: in this research, the simulation of the detector and collimator of spect imaging device, model hd3 made by philips co. and the investigation of important factors on the collimator were carried out using mcnp-4c code. results: the results of the experimental measurments and simulation calculations revealed a relative difference of less than 5% leading to the confirmation of the accuracy of conducted simulation mcnp code calculation.  conclusion: this is the first essential step in the design and modelling of new collimators used for creating high quality images in nuclear medicine.