Application of iterative model reconstruction technique in CT pulmonary angiography with lower radiation dose and lower contrast medium / 实用放射学杂志

ABSTRACT

Objective To observe the value of iterative model reconstruction(IMR)technique in CT pulmonary angiography (CTPA)with lower radiation dose and lower contrast medium.Methods 60 patients with clinical suspicion of pulmonary embolism underwent 256-slice CTPA were prospectively enrolled.The raw data of test group(n=30)were reconstructed by filtered back projection (FBP)(group A)and IMR technique (group B).And the raw data of control group(n=30)were reconstructed by FBP(group C).The values of volume CT dose index(CTDIvol),effective radiation dose (ED)were recorded and calculated.The image quality parametersCT value,image noise,signal-to-noise (SNR),contrast-to-noise ratio (CNR)and subjective image score(from one to five)were measured and compared between group A and B,B and C.Results The BMI was no statistically significant difierenee between two groups(P=0.001).The CTDIvol, ED on test group were respectively lower than that on control(P<0.001).The CT value was no statistically significant difierenee between group A and B(P=0.999).The CT valueon group B was higher than that on group C(P=0.005).The image noise on group B was lower than that on group A(P<0.001),but which was higher than that on group C(P<0.096).The SNR,CNR on group B were higher than that on group A(P<0.001).The SNR,CNR did not differ significantly between B and C(P=0.831,P=0.958).The diagnosable rate and good quality rate on group B were higher than that on group A(P<0.001),and there were no significantly diferent between B and C(P=1.000).Conclusion The application of optimized IMR technique can improve image quality at lower radiation dose and lower contrast medium for CTPA.