Objective To study the accuracy of the anteversion of femoral prosthesis in hemiarthro-plasty for treating femoral intertrochanteric fracture in the elderly.Methods Twenty femoral neck antever-sions of specimens were measured, which were control group(A).The femoral specimens were made into the model of femoral intertrochanteric fracture, which were installed femoral prosthesis according to minor trochanter(B),identifying the max diameter of cavum medulla(C),ocular estimating femoral condylar line ( D) ,combination of identifying the max diameter of cavum medulla and ocular estimating femoral condylar line( E) respectively.All the anteversion of femoral prosthesis were measured.Results The anteversion were:A group(8.98 ±4.31)°,B group (9.12 ±4.87)°,C group (9.57 ±6.49)°,D group (13.18 ± 5.83)°,E group (10.37 ±4.56)°respectively.The difference among the five groups was statistically sig-nificant.There was difference between D and A, there were no differences between B and A, C and A, E and A respectively.Conclusions In hemiarthroplasty for treating femoral intertrochanteric fracture, the an-teversion of femoral prosthesis is according to minor trochanter possibly; if the minor trochanter can not be got reduction, it is a good option according to combination of identifying the max diameter of cavum medulla and ocular estimating femoral condylar line to make sure the accuracy of the anteversion of femoral prosthe-sis.

Objective To compare the image quality and radiation dose of prospective electrocardiogram(ECG)-triggered high-pitch spiral scan,prospectively triggered sequential scan and retrospectively triggered spiral scanning mode by dual-source CT in the follow-up of coronary artery bypass graft(CABG).Methods Totally 90 patients with stable heart rate(≤65 beats per minute)after bypass surgery were randomized to undergo prospective high-pitch spiral scan in group A (n=30),prospective sequential scan in group B (n=30),and retrospective spiral scan in group C (n=30).The patency and image quality of the grafts were blindly evalua-ted by two independent readers.Moreover,radiation dose of the three modes were evaluated.Results Scanning time of group A was significantly shorter than that of group B and group C (P<0.05).The average image quality score had no significant difference among three groups(H=0.449,P=0.799).The effective radiation dose of group A,group B and group C were (2.64±1.21)mSv, (6.48±2.58)mSv and(18.95±7.16)mSv,which was significantly lower in group A(H=101.21,P=0.00).Conclusion In pa-tients with a stable HR of 65 beats per minute or less,high-pitch spiral CT scan provides similar image quality at lower radiation dose compared with sequential scan and retrospective spiral scan,which can be widely used as a non-invasive effective tool for the post-operative follow-up of CABG.