Dose-optimized computed tomography of the cervical spine in patients with shoulder pull-down: Is image quality comparable with a standard dose protocol in an emergency setting?. Issue 120 (November 2019)

• Record Type: Journal Article
• Authors: Tozakidou, Magdalini; Yang, Schu-Ren; Kovacs, Balazs K.; Szucs-Farkas, Zsolt; Studler, Ueli; Schindera, Sebastian; Hirschmann, Anna
• Is Part Of: European journal of radiology. Issue 120(2019)
• Publication Date: 2019-11
• Subjects: BMI body-mass-index -- C-spine cervical spine -- CT computed tomography -- CTDIvol volume CT dose index -- DO dose optimized -- DLP dose–length product -- ED effective dose -- HU Hounsfield units -- IR iterative reconstruction -- ROI regions of interests -- SD standard dose -- SAFIRE sinogram-affirmed iterative reconstruction; Dose reduction -- Spine trauma -- CT-reconstruction techniques; Medical radiology -- Periodicals; Radiology -- Periodicals; Radiologie médicale -- Périodiques; Medical radiology; Periodicals; 616.075705
• DOI: 10.1016/j.ejrad.2019.108655
• Languages: English
• ISSNs: 0720-048X

Abstract

Highlights: Soft tissue and bone superimposition is a limiting factor in computed tomography of the cervical spine. Cervical spine CT with dose reduction showed no image quality impairment. Low shoulder position is crucial for optimization of CT-imaging of the cervical spine. Abstract: Purpose: Superimposing soft tissue and bony structures in computed tomography (CT) of the cervical spine (C-spine) is a limiting factor in optimizing radiation exposure maintaining an acceptable image quality. Therefore, we assessed image quality of dose-optimized (DO) C-spine CT in patients capable of shoulder pull-down in an emergency setting. Methods and materials: DO-CT (105mAs/120 kVp) of the C-spine in trauma settings was performed in patients with shoulder pull-down if C5 was not superimposed by soft tissue on the lateral topogram, otherwise standard-dose (SD)-CT (195 mAs/120 kVp) was performed. 34 DO (mean age, 68y ± 21; BMI, 24.2 kg/m 2 ± 3.2) and 34 SD (mean age 70y ± 19; BMI 25.7 kg/m 2 ± 4.4) iterative reconstructed CTs were evaluated at C2/3 and C6/7 by two musculoskeletal radiologists. Qualitative image noise and morphological characteristics of bony structures (cortex, trabeculae) were assessed on a Likert scale. Quantitative image noise was measured and effective dose (ED) was recorded. Parameters were compared using Mann-Whitney- U -test (p < 0.05). Results: At C2/3, DO-CT vs. SD-CT yielded comparable qualitative noise (mean, 1.3 vs. 1.0; p = 0.18) and morphological characteristics, but higher quantitative noise (27.2 ± 8.8HU vs. 19.6 ± 4.5HU; p < 0.001). At C6/7, DO-CT yielded lower subjective noise (1.9; SD-CT 2.2; p = 0.017) and better morphological characteristics with higher visibility scores for cortex (p = 0.001) and trabeculae (p = 0.03). Quantitative noise did not differ (p = 0.24). Radiation dose was 51% lower using DO-CT (EDDO-CT 0.80 ± 0.1 mSv; EDSD-CT 1.63 ± 0.2 mSv; p < 0.001). Conclusion: C-spine CT with dose reduction of 51% showed no image quality impairment. Additional pull-down of both shoulders allowed better image quality at lower C-spine segments as compared to a standard protocol.