Skip to main content

Table 1 Scan parameters of the standard (original) cohort and the proof-of-concept cohort

From: Ultra-low-dose computed tomography for torsion measurements of the lower extremities in children and adolescents

Protocol Hip Knee Ankle
Standard Proof of concept Standard Proof of concept Standard Proof of concept
Automated tube current modulation + automated tube voltage selection On On Off Off Off Off
Tube voltage (kV) 100 (selected by software) 100 (selected by software) 80 80 80 80
Tube current–time product (mAs) 50(*)/70 (ref. mAs(**)) 15(*)/21 (ref. mAs(**)) 35 10 25 8
Tube filter Wedge2(*)/flat Wedge2(*)/flat Wedge2(*)/flat Wedge2(*)/flat Wedge2(*)/flat Wedge2(*)/flat
Pitch 0.8 0.8 0.8 1.0 0.8 1.25
Rotation time (s) 0.5 0.5 1 0.5 1 0.5
Total collimation (mm) 38.4 (0.6 * 64) 38.4 (0.6 * 64) 38.4 (0.6 * 64) 38.4 (0.6 * 64) 38.4 (0.6 * 64) 38.4 (0.6 * 64)
CTDI vol [mGy] (SSDE/Child phantom) 1.9 ± 0.6(*)/3.3 ± 0.6 (mean SSDE) 0.8 ± 0.1(*)/1.4 ± 0.3 (mean SSDE) 1.14(*)/1.48 0.32(*)/0.42 0.82(*)/1.06 0.24(*)/0.34
CTDI vol reduction (%) 55(*)–58% 72% 68–71(*) %    
  1. (*)Age < 12 years
  2. (**)Actual effective cube current chosen by automated tube current modulation