A systematic review on the current status of adult diagnostic reference levels in head, chest and abdominopelvic Computed Tomography

Abstract

Computed tomography (CT) is a routinely employed diagnostic tool for the detection and diagnosis of disease processes. Despite the primary focus of radiation dose reduction and improvements in CT scanners, radiation dose exposure remains an ever-increasing concern. Scanning protocol optimisation relative to body weight and scanner manufacturer still lags behind the diagnostic reference levels (DRLs) that are set on an international scale. The aim of this systematic review is to evaluate the current status of adult DRLs in head, chest and abdominopelvic CT over time on a global scale. A search was carried out in early 2019 using the Medline, PubMed, EMBASE, SCOPUS and manual databases. The reference lists of published articles were also assessed to identify further articles. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology was employed to evaluate articles for relevance. Articles were included if they assessed the DRL in head, chest and abdominopelvic scans. The search resulted in 6079 articles, of which 67 were included after a thorough screening process. The literature demonstrates a wide dose variation in reported head, chest and abdominopelvic dose length product (DLP) DRL, ranging from 700–1359, 330–707 and 550–1486 mGy·cm, respectively. Where reported, the volumed CT dose index (CTDIvol) DRL in the head, chest and abdominopelvic studies ranged from 30.4–85.5, 9–15 and 12.3–31 mGy·cm, respectively. The global means were shown to be slightly lower and significantly lower than the reported values of DLP and CTDIvol values for the American College of Radiology and European Commission, respectively. This review emphasises the need for an international standardisation for head and body DRL establishment methods, to provide a more comparable global measurement of dose variations across CT sites as well as regular monitoring of delivered radiation dose to patients.

Academic achievement after a CT examination toward the head in childhood: Follow up of a randomized controlled trial

“…In the year 2018 the number of CT scans in Sweden was 1.5 million, an increase of 130% compared to 2005 [ 3 ]. Over time, technological advances and awareness of radiation protection has led to lowered doses to the head in diagnostic CT scans, but the comparably high doses of ionizing radiation from CT remain a concern, especially since the number of scans continue to increase [ 4 – 6 ].…”

A survey of local diagnostic reference levels for the head, thorax, abdomen and pelvis computed tomography in Norway and Canada

“…11 Many countries have implemented National DRLs (NDRL) and Local DRLs (LDRL), which have demonstrated a reduction in patient dose over time. 12,13 National reference levels in CT were established in 2018 in Norway 14 and in 2016 in Canada. 15 The diagnostic imaging department can use NDRLs and LDRLs as a guide to optimizing CT scanning protocols according to patient characteristics to reduce patient dose to meet the 'as low as reasonably achievable' (ALARA) principle while maintaining acceptable image quality.…”

Comparing model based iterative reconstruction to hybrid based iterative reconstruction in stenosis detection during ECG-gated coronary CTA

“…These iterative reconstruction (IR) algorithms were introduced in 2008 with the aim of reducing image noise and radiation dose while increasing con dence in pathology detection (2,3,4). However, while there is signi cant advances in radiation dose reduction, a great lag still remains in determining and optimizing the reconstruction techniques that enables reliable pathology detection with reasonably lower radiation dose levels (5).…”