Diagnostic reference levels and median doses for common clinical indications of CT: findings from an international registry

Denise Bos, Sophronia Yu, Jason Luong, Philip Chu, Yifei Wang, Andrew J. Einstein, Jay Starkey, Bradley N. Delman, Phuong Anh T. Duong, Marco Das, Sebastian Schindera, Allen R. Goode, Fiona MacLeod, Axel Wetter, Rebecca Neill, Ryan K. Lee, Jodi Roehm, James A. Seibert, Luisa F. Cervantes, Nima KasraiePavlina Pike, Anokh Pahwa, Cécile R.L.P.N. Jeukens, Rebecca Smith-Bindman

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Objectives: The European Society of Radiology identified 10 common indications for computed tomography (CT) as part of the European Study on Clinical Diagnostic Reference Levels (DRLs, EUCLID), to help standardize radiation doses. The objective of this study is to generate DRLs and median doses for these indications using data from the UCSF CT International Dose Registry. Methods: Standardized data on 3.7 million CTs in adults were collected between 2016 and 2019 from 161 institutions across seven countries (United States of America (US), Switzerland, Netherlands, Germany, UK, Israel, Japan). DRLs (75th percentile) and median doses for volumetric CT-dose index (CTDIvol) and dose-length product (DLP) were assessed for each EUCLID category (chronic sinusitis, stroke, cervical spine trauma, coronary calcium scoring, lung cancer, pulmonary embolism, coronary CT angiography, hepatocellular carcinoma (HCC), colic/abdominal pain, appendicitis), and US radiation doses were compared with European. Results: The number of CT scans within EUCLID categories ranged from 8,933 (HCC) to over 1.2 million (stroke). There was greater variation in dose between categories than within categories (p <.001), and doses were significantly different between categories within anatomic areas. DRLs and median doses were assessed for all categories. DRLs were higher in the US for 9 of the 10 indications (except chronic sinusitis) than in Europe but with a significantly higher sample size in the US. Conclusions: DRLs for CTDIvol and DLP for EUCLID clinical indications from diverse organizations were established and can contribute to dose optimization. These values were usually significantly higher in the US than in Europe. Key Points: • Registry data were used to create benchmarks for 10 common indications for CT identified by the European Society of Radiology. • Observed US radiation doses were higher than European for 9 of 10 indications (except chronic sinusitis). • The presented diagnostic reference levels and median doses highlight potentially unnecessary variation in radiation dose.

Original languageEnglish
Pages (from-to)1971-1982
Number of pages12
JournalEuropean Radiology
Issue number3
StatePublished - Mar 2022


  • Adult
  • Diagnostic reference levels
  • Registries
  • Tomography, X-ray computed
  • United States


Dive into the research topics of 'Diagnostic reference levels and median doses for common clinical indications of CT: findings from an international registry'. Together they form a unique fingerprint.

Cite this