Objective:To analyze the characteristics of synovial sarcoma so as to enhance the level of awareness of this disease.Methods:MR imaging data of 8 patients with primary synovial sarcoma were retrospectively analyzed.Results:Eight cases of synovial sarcoma,including 2 men and 6 women,aged from 22 to 46 years,were enrolled.All cases showed soft-tissue mass,which were located close to the joints.On T1-weighted images,all tumors displayed signal isointensity relative to muscle.On T2-weighted images,tumors displayed signal hyperintensity.After Gd-DTPA injection,7 of them displayed marked enhancement,with 5 being homogeneous,2 being heterogeneous which had necrotic areas and cystic areas inside.and 1 displaying slight enhancement which had calcification inside and invaded the adjacent bones.Five tumors had internal septa and one tumor encased vicinal tendon sheaths.Conclusion:MR can accurately find the tumors and displays signal characteri-stics such as position,shape,necrotic area,internal septa,and the invasion into the adjacent soft-tissues and bones.MR examination plays an important role in diagnosing synovial sarcoma.

Objective To analyze the differences of ADC values in breasts of women of different ages and different menstrual phases, so as to direct the choice of the examination time of MR DWI. MethodsThe breasts of 65 healthy volunteers were scanned with the routine MRI plain scan and DWI in the menstrual, proliferative and secretary phases. DWI was conducted with single shot echo planar imaging technique and b value were 0, 1000 s/mm2. The women were divided into three groups: Group 1(aged 20 to 29 years, 21 cases), Group 2 (aged 30 to 39, 21cases), and Group 3 (aged 40 to 49, 23 cases). The ADC values of all 130 breasts at nipple level in the different phases were measured. The ADC values in the three age groups and in the different menstrual phases were compared using ANOVA. Results The mean ADC values of Group 1 were (2.14±0.14) ×10-3, (2.03±0.18) ×10-3and (2.10±0.19)×10-3mm2/s for left breast, and (2.08±0.17) ×10-3, (2.02±0.16) ×10-3and (2.09±0.17) ×10-3mm2/s for right breast in the menstrual, proliferative and secretary phases. They were slightly higher than Group 3, which were (2.02±0.27) ×10-3, (1.97±0.25) ×10-3and (2.03±0.22)×10-3 mm2/s for left breast and (1.99±0.29) ×10-3, (1.93±0.26) ×10-3and (2.03±0.28)×10-3 mm2/s for right breast. The mean ADC values of Group 2 [left breast: (1.94±0.25) ×10-3, (1.91±0.21) ×10-3and (1.97±0.21)×10-3 mm2/s ; right breast: (1.97±0.26)×10-3, (1.89±0.25)×10-3and (1.96±0.22)×10-3 mm2/s) were the lowest among the three age groups. There were significant differences in different menstrual phases (F= 23.600, P＜0.01), but no statistical difference was found among the three age groups or between left breasts and right breasts (F= 1.683, 2.248;P＞0.05).Conclusions The mean ADC values of breasts decrease markedly in the proliferative phase.The effects of the menstrual cycle on the breast ADC values should be considered in the evaluation of breast diseases with DWI.

Objective To estimate the applications of ADC value and rADC value in the diagnosis of nodular lesions of breasts.Methods Fifty-two cases with 66 nodular lesions of breasts confirmed by histopathology underwent diffusion-weighted magnetic resonance imaging.Three b values (0,800 and 1000 s/mm2) were applied.The mean ADC values of the breast nodules,the ADC values of ipsilateral breast( rADC1 ) and ADC values of contralateral breast (rADC2 )were respectively measured.The independent-samples t-test and chi-square test were used for statistical analyses.Results Of the 52 patients,there were 18 patients with infiltrating ductal carcinoma and 34 patients with fibroadenoma.50 patients with 64 lesions were examined by DWI.( 1 ) at b = 800 s/mm2,the mean ADC values of malignant nodules [ ( 1.01 ±0.09) × 10-3 mm2/s],rADC800-1 (0.52 ±0.07)and rADC800-2 (0.51 ±0.06) were lower than that of the benign nodules [ ADC value = ( 1.54 ± 0.28 ) × 10 -3 mm2/s,t = 8.217,P ＜ 0.01 ; rADC800-1 =0.77 ±0.15,t =9.339,P＜0.01 ; rADC800-2 =0.76 ±0.14,t = 10.394,P ＜0.01 ].The one-side upper limits of 95％ medical reference value of mean values of infiltrating ductal carcinoma were adopted as the threshold point to distinguish the malignant from the benign.The threshold value of breast malignant nodule ADC,the rADC800-1 and rADC800-2 were respectively 1.05 × 10-3 mm2/s,0.55 and 0.53.The sensitivities of the three methods were 75.0％,65.0％ and 60.0％ ; the specificities were 100.0％,95.7％ and 97.8％ ;the positive predictive values were respectively 100.0％,86.7％ and 92.3％ ; the negative predictive values were 90.2％,86.3％ and 84.9％; the diagnosis accordance rates were respectively 92.4％,86.4％ and 86.4％.( 2 ) at b = 1000 s/mm2,the mean ADC values of malignant nodules [ ( 0.93 ± 0.08 ) ×10-3 mm2/s],rADC1000-1 (0.53 ±0.09) and rADC1000-2 (0.52 ±0.07) were also lower than that of the benign nodules[ ADC value= (1.45 ±0.28) ×10-3 mm2/s,t=11.844,P＜0.01; rADC1000-1 =0.75 ±0.16,t=5.820,P ＜ 0.01 ; rADC1000-2 = 0.74 ± 0.15,t = 8.082,P ＜ 0.01 ].The threshold value points breast malignant nodule ADC,the rADC1000-1 and rADC1000-2 were respectively 0.97 × 10-3 mm2/s,0.58,0.55.The sensitivities were all 70.0％ ; the specificities were respectively 100.0％,95.7％ and 93.5％ ;the positive predictive values were 100.0％,87.5％ and 82.4％ ; the negative predictive values were 88.5％,88.0％ and 87.8％ ; the diagnosis accordance rates were 90.9％,87.9％ and 86.5％ respectively.There were no significant differences in specificities and the diagnosis accordance rates ( x2 = 1.232,2.263 ; P =0.942,0.812 ).Conclusions ADC value and rADC value are both important parameters of MRI in differentiating benign and malignant breast diseases.The study indicated that ADC value ( at b =800 s/mm2) was the most valuable parameter.

Objective:To analyze the CT and MRI features of liposarcoma of the extremities and trunk for improving the diagnosis of the disease.Methods:The CT and MRI findings of 12 cases of primary liposarcoma confirmed by operation and pathology were analyzed retrospectively.Seven cases were examined by CT,11 cases by MRI,and 6 cases by both CT and MRI.Results:Among the 12 cases,6 were well differentiated liposarcoma,2 sclerosing liposarcoma,3 myxoid iposarcoma,2 pleomorphic and 1 was dedifferentiated liposarcoma.Seven cases were irregularly margined and five cases regularly margined.The mean diameter of the lesions ranged from 6.1 to 19.9 cm.Well differentiated liposarcom contained a large amount of mature fat.CT and MRI showed fat tissue which was well defined,and homogeneous in density and signal intensity(SI).Myxoid liposarcoma consisted mainly of myxoid matrix,containing a few well differentiated proliferating lipoblasts;CT and MRI demonstrated no or little fat with irregular density and mildly inhomogeneous SI.Pleomorphic liposarcoma had no characteristic of fat tissue,and the adjacent structures were infiltrated and edematous with apparently inhomogeneous density and SI.Dedifferentiated liposarcoma had a pretty large volume with apparently inhomogeneous density and SI.The enhancement was highly intensified.Conclusions:CT and MRI can reflect the histological features of liposarcoma of the extremities and trunk,and demonstrate the exact boundaries of tumors,the actual area and surrounding tissues.The degree of histology differentiation and malignancy can be evaluated on the basis of CT and MRI findings of liposarcoma.

Objective:To evaluate the clinical value of subtraction CT angiography(CTA) in the intracranial aneurysms.Methods:33 cases were examined by CTA. The obtained images were 3D postdisposed with(method A) and without(method B) subtraction respectively.Two sets of the images were reconstructed using the techeniques of maximum intensity(MIP),shaded surface display(SSD) and volume rendering(VR).In evaluating all the images by two experienced neurologists and two radiologists,double blind method were adopted.Results:By the method A 36 intracranial aneurysms were detected in 33 cases,aneurysmal body and neck,parent artery and relationship to adjacent vessels were displayed clearly and exactly.While by method B only 29 aneurysms were detected,1 anterior cerebral artery anerrysm,2 anterior communication and artery carotis interna anerrysms were not displayed.The detecting rate of the aneurysm were 100%,with high ratio by method A than 86% by method B(χ~2=5.13,P0.05).Conclusion:The 3D subtraction CTA is superior to 3D CTA in the diagnosis of intracranial aneurysms.

由于螺旋CT扫描速度极快,一次屏气即可完成全肝或全胸的扫描,因此必须使用高压注射器进行大剂量快速注射造影剂方能在强化的峰值期获得最佳数据,从而有利于病灶的检出.但对于局部静脉损伤严重,为此,我们采取了严格选择和使用静脉及提高穿刺成功率等综合防护措施,对减轻静脉损伤和渗漏有显著效果.

目的评价CT仿真内窥镜成像在显示喉部疾病的应用价值.方法22例喉部疾病患者包括15例喉癌,3例声带息肉,1例披裂炎症,1例咽喉后壁脓肿,以及2例声带固定,均经螺旋CT扫描,获自所有病例的仿真内窥镜成像均与纤维喉镜及手术所见对照分析.所有病例经病理或细胞学证实.结果CT仿真喉镜对正常解剖结构显示与纤维喉镜一致,显示病变范围优于纤维喉镜,CT仿真喉镜能从足端入路观察,但对较小病灶的显示不如纤维喉镜.结论CT仿真喉镜能对喉部病变提供较全面的信息,因而它是纤维喉镜的一种很好补充手段.

目的研究舌下神经鞘瘤的CT、MRI特征性表现.方法回顾分析了4例经手术病理证实的舌下神经鞘瘤CT和MRI表现.结果从病变部位看,右侧3例,左侧1例;颅内段2例,颅内与颅外段同时受累2例.CT表现:舌下神经孔扩大和骨质破坏,并见软组织块影2例.MRI表现:舌下神经径路上出现圆形、椭圆形的软组织块影4例,T1WI为等信号,T2WI为等信号和高信号;有明显的强化.结论舌下神经径路上出现软组织块影是其特点;MRI对舌下神经鞘瘤的诊断优于CT,特别是MRI增强扫描.

目的探讨螺旋CT双期扫描对小胰头癌的诊断价值.方法18例经手术及病理证实的小胰头癌患者,均行螺旋CT双期扫描,层厚3～10mm,螺距为1.0,注射造影剂后25s行动脉期扫描;60～70s行门脉期扫描.结果CT平扫13例肿瘤病灶为低密度,5例呈等密度,螺旋CT双期扫描均呈低密度改变,同时14例胰管有不同程度的扩张,8例胆总管扩张,5例血管周围脂肪内浸润.结论螺旋CT双期扫描对小胰头癌诊断有重要价值,并对小胰头癌的可切除性可做出准确的术前评价.