دز جذبي تيروييد و عدسي چشم در تصويربرداري از سر و گردن به روش سي تي اسكن

Absorbed Dose in Thyroid and Eyes Lenses in CT Scans of Head and Neck

While head is exposed to x-rays for CT Scan some of the sensitive tissues such as thyroid and eye lenses are also exposed. In this study the resultant absorbed dose to these tissues have been measured by Thermolumincent Dosimeters (TLD), in patients admitted to the CT Scan ward, in Imam Reza Hospital in 1999. For this purpose TL pellets made from LiF: Mg, Ti were used The CT Scan machine used in this work wasaGECT 9800HL. The head scans investigated in this work were divided into five groups. Group one general head scans of patients over 16 years old. Group two head scans of patients below 16 years old, group three scans of patients eye orbit, group four scans of patientsʹ sinus and group five scans of patientsʹ sinus ear. Average eye lenses doses of patients examined in this study were: 3.22, 3.67, 22.2, 21.6 and 19.9 mGy for group one to five respectively. Average thyroid dose of patients included in this work were 0.78, 0.97, 0.52, 0.93 and 0.49 mGy respectively for group one to five. As absorbed dose in Eyes Lenses from the Thermolumincent Dosimetry in CT Scan of patients sinuses and eyes orbits and ears are higher than limit, it must be considered in use of CT Scan and other diagnostic radiographics.