Establishment of CT diagnostic reference levels in select procedures in South India

Abstract

Background: To suggest South India CT diagnos c reference levels (DRLs) by collec ng radia on doses for the most commonly performed CT examina ons. Materials and Methods: A pilot study inves gated the most frequent CT examina ons. 110 CT sites were asked to complete a survey booklet to allow the recording of CT parameters for each of 3 CT examina ons during a 1 year me period. Dose data such Volumetric Computed Tomography Dose Index (CTDI v ) and Dose length product (DLP) on a minimum of 50 average-sized pa ents in each category were recorded to calculate a mean site CTDI vol and DLP value. The rounded 75 th percen le was used to calculate a DRL for each site and the region by compiling all results. Results are compared with interna onal DRL data. Results: Data were collected for 16,500 pa ents. All equipment had mul slice capability (2-256 slices). DRLs are proposed using CTDI vol (mGy) and DLP (mGy.cm) for CT head (47 and 1041 respec vely), CT chest (10 and 445 respec vely), and CT abdomen (12 and 550 respec vely). These values are lower than current DRLs and comparable to other interna onal studies. Wide varia ons in mean doses are noted across the region. Conclusion: Baseline figures for South India CT DRLs are provided on the most frequently performed CT examina ons. It was noted that there was a wide varia on in mean doses among the CT scanners used during diagnosis. The differences in CT doses between CT scanner departments as well as iden cal scanners suggest a large poten al for op miza on of examina ons.Keywords: Com puted tomography (CT), w eighed com puted tomography dose index (CTDI w ), volumetric computed tomography dose index (CTDI v ), dose length product (DLP), dose reference level (DRL).

Assessment of dose reduction and influence of gantry rotation time in CT abdomen examinations

“…However, shields are associated with greater image noise and streak artefacts (8) . Some studies have been published in radiation protection to patients during CT procedures (9)(10)(11)(12)(13)(14) . These studies have shown that there is a wide range of dose values and acquisition protocols.…”

Radiation dose metrics in multidetector computed tomography examinations: A multicentre retrospective study from seven tertiary care hospitals in Kerala, South India

“…Even though there is enough recently published regional CT radiation dose data from south India,[ 15 16 17 18 ] any such data have not considered the make of CT equipment (number of slices of CT) and actual number of phases in contrast CT examinations. These factors are important with regard to actual dose delivered to the patient.…”