Chest X-ray Dose Equivalent Low-dose CT with Tin Filtration: Potential Role for the Assessment of Pectus Excavatum

Olivia Messerli-Odermatt; Bettina Serrallach; Manuel Gubser; Sebastian Leschka; Ralf W Bauer; Josée Dubois; Hatem Alkadhi; Simon Wildermuth; Stephan L Waelti

doi:10.1016/j.acra.2019.07.017

Chest X-ray Dose Equivalent Low-dose CT with Tin Filtration: Potential Role for the Assessment of Pectus Excavatum

Acad Radiol. 2020 May;27(5):644-650. doi: 10.1016/j.acra.2019.07.017. Epub 2019 Aug 28.

Authors

Olivia Messerli-Odermatt¹, Bettina Serrallach², Manuel Gubser², Sebastian Leschka³, Ralf W Bauer⁴, Josée Dubois⁵, Hatem Alkadhi⁶, Simon Wildermuth², Stephan L Waelti⁷

Affiliations

¹ Department of Dermatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland. Electronic address: Olivia.Messerli-Odermatt@usz.ch.
² Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, Switzerland.
³ Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, Switzerland.
⁴ RNS Gemeinschaftspraxis GbR, Private Radiology and Radiation Therapy Group, Wiesbaden, Germany.
⁵ Department of Medical Imaging, Sainte Justine Hospital, University of Montreal, Montreal, Canada.
⁶ Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
⁷ Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, Switzerland; Children's Hospital of Eastern Switzerland, St. Gallen, Switzerland.

PMID: 31471205
DOI: 10.1016/j.acra.2019.07.017

Abstract

Rationale and objectives: To determine the value of chest CT with tin filtration applying a dose equivalent to chest x-ray for the assessment of the Haller index for evaluation of pectus excavatum.

Materials and methods: Two hundred seventy-two patients from a prospective single center study were included and underwent a clinical standard dose chest CT (effective dose 1.8 ± 0.7 mSv) followed by a low-dose CT (0.13 ± 0.01 mSv) in the same session. Two blinded readers independently evaluated all data sets. Image quality for bony chest wall assessment was noted. Radiologists further assessed (a) transverse thoracic diameter, (b) anteroposterior thoracic diameter, and calculated (c) Haller index by dividing transverse diameter by anteroposterior diameter. The agreement of both readers in standard dose and low-dose CT was assessed using Lin's concordance correlation coefficient (p_c).

Results: Subjective image quality was lower for low dose compared to standard dose CT images by both readers (p < 0.001). In total, 99% (n = 540) of low-dose CT scans were rated as diagnostic for bony chest wall assessment by both readers. There was a high agreement for assessment of transverse diameter, anteroposterior diameter and Haller index comparing both readers in standard dose and low-dose CT with p_c values indicating substantial agreement (i.e., 0.95> and ≤0.99) in 12/18 (67%) and almost perfect agreement (i.e., >0.99) in 6/18 (33%).

Conclusion: Our study suggests that low-dose CT with tin filtration applying a radiation dose equivalent to a plain chest X-ray is excellent for assessing the Haller index.

Keywords: Computed tomography; Haller index; Low-dose CT; Pectus excavatum; Tin filtration.

MeSH terms

Funnel Chest* / diagnostic imaging
Humans
Prospective Studies
Radiation Dosage
Reproducibility of Results
Tin*
Tomography, X-Ray Computed
X-Rays

Substances

Tin