Dose Reduction and Image Quality in Pulsed Fluoroscopy

Abstract

Pulsed fluoroscopy is an important too for dose reduction in fluoroscopic procedures. Evaluation of image quality and dose is necessary to optimise this technique. Image quality was evaluated for a grid controlled (Philips Diagnost 97) and a generator controlled (Siemens Sireskop SX 40) pulsed fluoroscopic system by phantom measurements and in routine clinical use. Spatial resolution and low contrast detectability were assessed in moving phantoms and under static conditions. Dose measurements were performed at the image intensifter entrance. For clinical aspects quality of last image hold (LIH) images of clinical examinations taken from pulsed and continuous fluoroscopy were graded in comparison to single shot exposures. Dose rate could he reduced to 10-46% of the contmuous mode. Detectability of low contrast objects and spatial resolution were improved in moving objects in pulsed fluoroscopy. Quality of LIH images of pulsed fluoroscopy was graded to be superior in comparison to the continuous mode. By suitable combinations of pulse frequency and pulse dose, reduction ion of radiation exposure and improvement of image quality can be achieved.