Abstract
Objectives To compare image quality and radiation dose between
high-pitch mode (HPM) and low-pitch mode (LPM)
CT in young children.
Materials and methods Forty-seven children (mean age
35.6 months; range, 0–126 months) underwent 49 CT examinations
in HPM or LPM and were divided into high or low
respiratory rate (RR) groups. A qualitative image quality was
compared between the two modes. The volume CT dose index
(CTDIvol) and dose-length product (DLP) were evaluated
from the dose reports, and effective doses were assessed using
a paediatric phantom.
Results Image quality was generally better for HPM than
LPM (diagnostic acceptance score, 4.00 vs. 3.46, P=0.004);
the difference was more prominent in the high RR group (4.00
vs. 3.22, P=0.001). However, there was no significant difference
in the low RR group. The mean DLP value was higher in
HPM than LPM (29.48 mGy·cm vs. 23.46 mGy·cm, P=0.022), while CTDIvol was not significantly different. The
total effective radiation dose was 26 % higher in HPM than
LPM (1.82 mSv vs. 1.44 mSv).
Conclusions LPM can be considered for paediatric lung evaluation
in young children with low RRs to reduce radiation
dose while maintaining favourable image quality.
Key Points
• Radiation exposure is higher on high-pitch BFlash spiral
mode^ than on low-pitch BX-CARE mode^.
• BFlash spiral mode^ generally showed better image quality
than BX-CARE mode^.
• Difference in image quality was more prominent in the high
RR group.
• There was no difference in image quality in the low RR
group.
• BX-CARE mode^ should be considered in a limited population
with low RRs.