Radiation doses in cerebral perfusion computed tomography: patient and phantom study

Area of Science:

• Medical Imaging
• Radiology
• Radiation Dosimetry

Background:

• Cerebral perfusion computed tomography (CT) is vital for diagnosing brain conditions.
• Accurate radiation dose assessment is crucial for patient safety in CT examinations.
• Understanding dose distribution, particularly to radiosensitive organs like the lens, is essential.

Purpose of the Study:

• To investigate and quantify radiation doses delivered during cerebral perfusion CT examinations.
• To assess doses to the skin and lens of the eye.
• To compare patient dose data with published literature and established safety thresholds.

Main Methods:

• Patient data collection including skin dose, CT dose index (CTDIvol), and dose-length product (DLP).
• Phantom study for estimating radiation dose to the lens of the eye.
• Estimation of effective dose for comprehensive risk assessment.

Main Results:

• Patient CTDIvol ranged from 230-680 mGy and DLP from 2120-2740 mGy cm.
• Skin doses ranged from 340-800 mGy, with estimated effective doses of 4.9-6.3 mSv.
• Phantom study showed lens doses of approximately 53 mGy (right) and 51 mGy (left), below deterministic effect thresholds.

Conclusions:

• Radiation doses in cerebral perfusion CT are within acceptable safety limits.
• The study confirms that doses to the skin and lens are below thresholds for deterministic effects.
• Findings support the safe clinical use of cerebral perfusion CT with appropriate monitoring.