Objective:

To evaluate the feasibility of adaptive iterative dose reduction 3D (AIDR 3D) combined with low tube voltage and low contrast agent in CT scan of the upper abdomen.

Methods:

A total of 60 patients were randomly divided into the conventional group [tube voltage 120 kV

filter back projection (FBP) reconstruction

contrast agent 1.5

mL/kg

]

and the low dose group (tube voltage 100 kV

AIDR 3D reconstruction

contrast agent 1.0 mL/kg). Each group had 30 cases. CT values of the liver

aorta

right erector spinae and abdominal subcutaneous fat were measured

and the contrast-to-noise ratio (CNR) of the aortic and liver and signal-to-noise ratio (SNR) were calculated. The volume CT dose index (CTDI

vol

) and the dose length product (DLP) were recorded

and the effective radiation dose (ED) was calculated. Images were evaluated for rating.

Results:

The differences in CT values of the aorta and liver

CNR

SNR and image noise between the two groups were not statistically significant (

P

0.05). There was no significant difference in subjective score between the two groups (

P

0.05). The CTDI

vol

and ED values in the low dose group were lower than those in the conventional group (

P

0.05).

Conclusion:

AIDR 3D combined with low tube voltage (100 kV) and low contrast agent can not only reduce the radiation dose and contrast agent

but also obtain the images that meet the requirement of diagnosis in CT scan of the upper abdomen.