Image Quality in Low-dose Multidetector Computed Tomography: A Pilot Study to Assess Feasibility and Dose Optimization in Whole-body Bone Imaging

Canadian Association of Radiologists Journal - Tập 61 - Trang 258-264 - 2010
Tadhg G. Gleeson1, Brenda Byrne2, Pat Kenny2, Jason Last3, Patricia Fitzpatrick4, Peter O'Gorman5, Steven J. Eustace1
1Department of Radiology and Diagnostic Imaging, Mater Misericordiae University Hospital, Dublin, Ireland
2Department of Medical Physics, Mater Misericordiae University Hospital, Dublin, Ireland
3Department of Anatomy, University College Dublin, Earlsfort Terrace, Dublin, Ireland
4School of Public Health and Population Science, University College Dublin, Earlsfort Terrace, Dublin, Ireland
5Department of Haematology, Mater Misericordiae University Hospital, Dublin, Ireland

Tóm tắt

Objective To study the impact of dose parameters on image quality at whole-body low-dose multidetector computed tomography (CT) in an attempt to derive parameters that allow diagnostic quality images of the skeletal system without incurring significant radiation dose in patients referred for investigation of plasma cell dyscrasias. Methods By using a single cadaver, 14 different whole-body low-dose CT protocols were individually assessed by 2 radiologists, blinded to acquisition parameters (kVp and mAs, reconstruction algorithm, dose reduction software). Combinations of kVps that range from 80-140 kVp, and tube current time product from 14–125 mAs were individually scored by using a Likert scale from 1–5 in 4 separate anatomical areas (skull base, thoracic spine, pelvis, and distal femora). Correlation between readers scores and effective doses were obtained by using correlation coefficient statistical analysis, statistical significance was considered P < .01. Interobserver agreement was assessed by using a Bland and Altman plot. Interobserver agreement in each of the 4 anatomical areas was assessed by using kappa statistics. A single set of parameters was then selected for use in future clinical trials in a cohort of patients referred for investigation of monoclonal gammopathy, including multiple myeloma. Results Several sets of exposure parameters allowed low-dose whole-body CT to be performed with effective doses similar to skeletal survey while preserving diagnostic image quality. Individual reader's and average combined scores showed a strong inverse correlation with effective dose (reader 1, r = −0.78, P = .0001; reader 2, r = −0.75, P = .0003); average combined scores r = −0.81, P < .0001). Bland and Altman plot of overall scores shows reasonable interobserver agreement, with a mean difference of 1.055. Conclusion Whole-body low-dose CT can be used to obtain adequate CT image quality to assess normal osseous detail while delivering effective doses similar to those associated with conventional radiographic skeletal survey.

Tài liệu tham khảo

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Thông tin xuất bản

Canadian Association of Radiologists Journal

Tập 61

258-264

Thông tin tác giả