Room: AAPM ePoster Library
Purpose:
Computed tomography perfusion (CTP) is an imaging procedure for evaluation of tissue-level perfusion and distribution of blood to the brain and soft tissue of the head and neck. The imaging sequence provides an evaluation of cerebral blood flow with the goal of identifying ischemic regions of the brain. The imaging protocol is valuable in aiding treatment decisions for acute ischemic stroke, subarachnoid hemorrhage, cerebral vasospasm, brain tumors, and head trauma. The radiation dose associated with CT Stroke protocols can be a hundred times higher than doses in conventional projection radiography. Recent advances in automated CTP techniques extend the clinical utility of the technique to patients who present more than 6 hours post medical event. The purpose of the study is to (1) quantify the dose to the lens of the eye for traditional CTP imaging; and (2) compare the lens dose to the automated CTP imaging techniques.
Methods:
Dose indices and acquisition parameters were collected for 100 patients imaged under a traditional CTP protocol and 120 patients imaged under an automated CTP protocol. Data was collected at the conclusion of every procedure by a radiation dose imaging monitoring (RDIM) system. The RDIM recorded CTDIvol, DLP, and the size of the CTDI phantom from the appropriate DICOM fields in the Radiation Dose Structured Report (RDSR). The RDIM estimated organ and effective dose indices for a reference phantom representative of the patient body habitus and age at the time of the procedure
Results:
The mean estimated dose to the lens of the eye for traditional CTP protocols was 359 mGy (sd = 32). The estimated dose to the lens of the eye for the automated CTP protocol was 395 mGy (sd = 50).
Conclusion:
The mean dose to the lens of the eye for automated CTP is greater than traditional CTP.
Not Applicable / None Entered.
Not Applicable / None Entered.