Establishment of diagnostic reference levels in computed tomography for select procedures in Pudhuchery, India

Abstract

Computed tomography (CT) scanner under operating conditions has become a major source of human exposure to diagnostic X-rays. In this context, weighed CT dose index (CTDIw), volumetric CT dose index (CTDIv), and dose length product (DLP) are important parameter to assess procedures in CT imaging as surrogate dose quantities for patient dose optimization. The current work aims to estimate the existing dose level of CT scanner for head, chest, and abdomen procedures in Pudhuchery in south India and establish dose reference level (DRL) for the region. The study was carried out for six CT scanners in six different radiology departments using 100 mm long pencil ionization chamber and polymethylmethacrylate (PMMA) phantom. From each CT scanner, data pertaining to patient and machine details were collected for 50 head, 50 chest, and 50 abdomen procedures performed over a period of 1 year. The experimental work was carried out using the machine operating parameters used during the procedures. Initially, dose received in the phantom at the center and periphery was measured by five point method. Using these values CTDIw, CTDIv, and DLP were calculated. The DRL is established based on the third quartile value of CTDIv and DLP which is 32 mGy and 925 mGy.cm for head, 12 mGy and 456 mGy.cm for chest, and 16 mGy and 482 mGy.cm for abdomen procedures. These values are well below European Commission Dose Reference Level (EC DRL) and comparable with the third quartile value reported for Tamil Nadu region in India. The present study is the first of its kind to determine the DRL for scanners operating in the Pudhuchery region. Similar studies in other regions of India are necessary in order to establish a National Dose Reference Level.

Cost-effective pediatric head and body phantoms for computed tomography dosimetry and its evaluation using pencil ion chamber and CT dose profiler

“…Also, from Tables 5 and 6 it is found that the percentage difference between the fabricated and console CTDI v and standard and console CTDI v are well within the limits recommended by Atomic Energy Regulatory Board (AERB) which is based on International Commission on Radiological Protection (ICRP) standards. [ 18 19 20 ] The large differences for lower kVs may be due to the dose evaluation/calibration method employed by the manufacturer.…”

Integration of An Information System to Suggest A Drl Model in Radiology Department at Azadi Hospital in Duhok–kurdistan Region, Iraq

“…One of these values to be calculated was the estimated length (L) measured in centimeter (cm) which was based on the CTDI vol and DLP generated by the CT scanner according to the following equation (Ekpo et. al., 2018) (Saravanakumar et. al., 2014).…”

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.…”