ABSTRACT
Objective To study the optimal enhancement phase and exact triggering scan time on spiral CT angiography of vertebral and carotid artery,and to improve the rate of 3D-CT display in vertebral and carotid artery.Methods One hundred and thirty-three cases of CT angiography of vertebral and carotid artery(87 vertebral and 46 carotid artery)were examined with SmartPrep software,which controled the scan at real time after 100 ml contrast medium(350 mg I/ml Omnipaque)were quickly injected through foot back vein.One hundred and thirteen cases of control group were examined by triggeing off the scanning with a delay time of 18—22 s after blous injection through foot back vein.The vertebral and carotid arteries were demonstrated with 3 dimensional reconstruction.Results The successful rate in SmartPrep group was 100% with the enhancement situated in best(n=130)or good(n=3)scanning phase.The threshold concentration values of target vessel were kept on 100 HU in the whole scan period[(18?4)s].However, the triggering time of enhancement scanning was not equal(15—43s)and the deviation was up to 28 s.The average concentration of target vessel was obviously higher in SmartPrep group[(161.4?2.0)HU]than in the control group[(133.3?2.2)HU](t=-9.456,P
ABSTRACT
Objective To evaluate MRI in the diagnosis of the bone contusion of the knee joint and its clinical significance.Methods Using special coil for knee joint,coronal,sagittal,axial and oblique sagittal plane scanning with fast spin-echo sequence(T_1WI,T_2WI,PDWI+FS)was performed on knee joint in 205 patients in three days after injury.According the distributing bone marrow edema and injury mechanism,bone contusion were classified five types as pivot shift injury,clip injury,dashboard injury, hyperextension injury and lateral patellar dislocation.Results One hundred and forty-five cases of the 205 patients were found bone marrow edema without fracture on X-ray films.Among them,pivot shift injury was found in 43 cases accompanied with anterior cruciate ligament rupture in 30 cases,tear of the posterior horn of the lateral or medial meniscus in 12 and tears of the medial collateral ligament in 8 cases;clip injury in 53 cases accompanied with anterior cruciate ligament rupture in 10 cases,tear of the posterior horn of the lateral or medial meniscus in 15 and tears of the medial collateral ligament in 38 cases;dashboard injury 40 cases accompanied with posterior cruciate ligament rupture in 16 cases,hyperextension injury 9 cases accompanied with anterior cruciate ligament rupture in 2 cases,posterior cruciate ligament rupture in 5 cases.No lateral patellar dislocation was found.Forty-eight of 145 patients had undergone arthroscopy, 43 cases(89.6%)of them were in accordance with MRI diagnosis.Bone contusion were defined as geographic regions of abnormal signal intensity,that is,low signal intensity in T_1-weighted images and high signal intensity in PD-weighted or T_2-weigeted images with fat saturation.Conclusion MRI can accurately display the location and area of bone contusion of the knee joint as well as its adjunctive structure injury and deduce their injury mechanism.MRI should be used routinely for knee trauma.