CT dose survey in adults: what sample size for what precision?
Objectives: To determine variability of volume computed tomographic dose index (CTDIvol) and dose-length product (DLP) data, and propose a minimum sample size to achieve an expected precision.Methods: CTDIvol and DLP values of 19,875 consecutive CT acquisitions of abdomen (7268), thorax (3805), lumb...
| Publicado en: | European Radiology Vol. 27; no. 1; pp. 365 - 374 |
|---|---|
| Autores principales: | , , , , , |
| Formato: | research Journal Article |
| Publicado: |
Springer Nature
Jan2017
|
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=119807673&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 119807673 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 09387994 NPH jtl: European Radiology issn: 09387994 maglogo: N pubinfo: dt: Jan2017 vid: 27 iid: 1 pid: 237 pub: Springer Nature place: New York, New York artinfo: ui: 119807673 119807673 NLM27048530 119807673 10.1007/s00330-016-4333-3 NLM27048530 119807673 ppf: 365 ppct: 9 formats: fmt: @attributes: type: P tig: atl: CT dose survey in adults: what sample size for what precision? aug: au: Taylor, Stephen Van Muylem, Alain Howarth, Nigel Gevenois, Pierre Tack, Denis Gevenois, Pierre Alain affil: Department of Radiology , Hôpital Ambroise Paré , Boulevard Président Kennedy 2 7000 Mons Belgium sug: subj: Radiation Dosage Tomography, X-Ray Computed Statistics and Numerical Data Retrospective Design Sample Size Female Adult Human Tomography, X-Ray Computed Methods Male Reproducibility of Results Validation Studies Comparative Studies Evaluation Research Multicenter Studies Adult: 19-44 years Female Male ab: Objectives: To determine variability of volume computed tomographic dose index (CTDIvol) and dose-length product (DLP) data, and propose a minimum sample size to achieve an expected precision.Methods: CTDIvol and DLP values of 19,875 consecutive CT acquisitions of abdomen (7268), thorax (3805), lumbar spine (3161), cervical spine (1515) and head (4106) were collected in two centers. Their variabilities were investigated according to sample size (10 to 1000 acquisitions) and patient body weight categories (no weight selection, 67-73 kg and 60-80 kg). The 95 % confidence interval in percentage of their median (CI95/med) value was calculated for increasing sample sizes. We deduced the sample size that set a 95 % CI lower than 10 % of the median (CI95/med ≤ 10 %).Results: Sample size ensuring CI95/med ≤ 10 %, ranged from 15 to 900 depending on the body region and the dose descriptor considered. In sample sizes recommended by regulatory authorities (i.e., from 10-20 patients), mean CTDIvol and DLP of one sample ranged from 0.50 to 2.00 times its actual value extracted from 2000 samples.Conclusions: The sampling error in CTDIvol and DLP means is high in dose surveys based on small samples of patients. Sample size should be increased at least tenfold to decrease this variability.Key Points: • Variability of dose descriptors is high regardless of the body region. • Variability of dose descriptors depends on weight selection and the region scanned. • Larger samples would reduce sampling errors of radiation dose data in surveys. • Totally or partially disabling AEC reduces dose variability and increases patient dose. • Median values of dose descriptors depend on the body weight selection. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
|---|