Abstract:
Objectives: To assess the level of patient dose in Computed Tomography examination
in Kenya, compare with the international diagnostic reference levels and establish the
initial national diagnostic reference levels.
Design: The patient doses for brain, chest, abdomen and pelvis examinations were
assessed using typical exposure factors on head and body dosimetry phantoms. A
log normal graphical method was developed and used in deriving the initial national
diagnostic reference levels for the two dose quantities.
Setting: Twenty one representative Computed Tomography facilities at different
hospitals and clinics.
Subjects: A questionnaire method was developed and used in recording the scanning
parameters for head, chest, abdomen and pelvis adult examinations at each facility.
Results: The radiation exposure from Computed Tomography examinations was
determined to be below the weighted Computed Tomography Dose Index (CTDlw)
and Dose Length Product (DLP) reference levels by 90% and 62% respectively.
Conclusion: The mean CTDlw measurements for the adult patients were below
Diagnostic Reference levels (DRLs). The mean DLP values for adult patients in some
examination were above DRLs, with large variations of up to a factor of eleven. This
indicates the need for local optimised scanning protocols and use of local diagnostic
reference level in order to reduce patient doses without affecting diagnostic image
quality.