Magdalini Tozakidou1, Schu-Ren Yang2, Balazs K Kovacs3, Zsolt Szucs-Farkas4, Ueli Studler5, Sebastian Schindera6, Anna Hirschmann7. 1. Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland; Department of Radiology and Nuclear Medicine, Devision of Pediatric Radiology, University Hospital Eppendorf, Hamburg, Germany. Electronic address: m.tozakidou@uke.de. 2. Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland. Electronic address: schu-ren.yang@usb.ch. 3. Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland. Electronic address: balazskrisztian.kovacs@usb.ch. 4. Department of Diagnostic Radiology, Hospital Centre of Biel, Switzerland. Electronic address: zsolt.szuecs@szb-chb.ch. 5. Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland; Imamed, Radiology Northwest, Basel, Switzerland. Electronic address: ueli.studler@imamed.ch. 6. Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland; Department of Diagnostic Radiology, cantonal hospital Aarau, Switzerland. Electronic address: sebastian.schindera@ksa.ch. 7. Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, University of Basel, Switzerland. Electronic address: anna.hirschmann@usb.ch.
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/m2 ± 3.2) and 34 SD (mean age 70y ± 19; BMI 25.7 kg/m2 ± 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.
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/m2 ± 3.2) and 34 SD (mean age 70y ± 19; BMI 25.7 kg/m2 ± 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.
Authors: Magdalini Tozakidou; Rieke L Meister; Lennart Well; Kay U Petersen; Sebastian Schindera; Eilin Jopp-van Well; Klaus Püschel; Jochen Herrmann Journal: Int J Legal Med Date: 2021-02-24 Impact factor: 2.686