Objective To sum up CT findings of sacroiliac joints in ankylosing spondylitis with an attempt at further improving early and even accurate diagnosis of the disease.Methods CT features of sacroiliac joints in 80 cases with anklyosing spondylitis proved clinically were analysed,and their application in making the diagnosis was evaluated.Results 73 of the 80 cases had abnormal CT findings of the joints,with different features according to different stages of the disease.In early stage,most cases were with symmetric involvement of the joints showing shaggy appearance of the articular surface with interruption or disappearance of the joint cortex,subcortical microcysts and mild sclerosis of iliac surface of joint .In advanced stage,cases were with irregularity of sacroiliac articular surfaces,showing serrated or brush-like appearance,subcortical systic destruction,sclerosis or hypertrophic changes around the joints,and pseudo-widening,irregular narrowing or even vacuumization of the joint space.In the late or stable stage,ossification of ligaments,bony ankylosis of the joints with obliteration of joint space and osteoporosis or osteosclerosis were seen.Conclusion CT study of sacroiliac joints could be helpful in making an early and even accurate diagnosis of ankylosing spondylitis as well as in clinical staging of the disease.

Objective To evaluate the clinical application of CT perfusion in predicting the status of axillary lymph nodes in patients with breast cancer.Methods Fony-five patients with infiltrating breast cancers and 46 clinically palpable axillary lymph nodes underwent dynamic mtdti-slice spiral CT(MSCT).Semi-automatic calculation of perfusion parameters including blood flow(BF),blood volume(BV),mean transit time(MTT)and permeability surface(PS)of "target" lymph nodes and muscles in the same scan level were respectively meagured and analyzed.Nonparametric Mann-Whitney U test was used for the statistics.Results Forty-six "target" lymph nodes examined by CTP were metastasis in 32 cases and reactive hyperplastic lymph node inflammation in 14 cases at pathology.22 of 32 metastatic "target" nodes (68%)were sentinel lymph nodes(SLN).BF of CIP for inflammation and metastatic "target" nodes were (76.18±31.53)and(161.60±40.94)ml·100 mg-1·min-1,BV were(5.81±2.50)and(9.15±3.02)ml／100 mg.MTT were(6.80±1.55)and(5.50±1.84)s,PS were(25.82±4.62)and (25.96±7.47)ml·100 mg-1·min-1.There were significant correlations between the BF value of inflammation and metastatic "target" nodes(r=0.14,P<0.05)and there were no significant correlations among the BV,MTT and PS values of inflammation and metastatic "target" nodes(r=-0.03,0.05,0.07.P>0.05).Conelusion CTP can provide useful informafion for evaluating lymph node status.