Objective To explore the value of the diagnosis and differential diagnosis of the sacral tumors with MRI. Methods Twenty nine patients with histologically proven sacral tumors were viewed, including sacral chordoma( n =5), giant cell tumor( n =1), neurilemmona( n =3), ganglioneuroma( n =2), malignant lymphoma( n =4), osteosarcoma( n =1), malignant neurilemmoma ( n =1), and secondary tumors ( n =12).All patients were examined with MR,CT and plain radiograph. MR findings were analyzed. Results (1) sacral tumors involved sacral bone with a regularity. Four patients with sacral chordoma involved usually above S3 level, not including S1 bone. One patient with giant cell tumor involved S2 S3. Six patients with neuromas involved S1 S3, including S1 bone. (2) signal intensity: moderate and/or low signal on T 1 weighted images, mottled signal on T 2WI. (3) sacral pores were destructed, disappeared, or enlarged. Sacral pores enlarged in six patients with neuromas, destructed in others. (4) sacral canal were destructed, disappeared, or enlarged. (5) tumors were classified into central ( n =16), centrifugal ( n =9), and mixed ( n =4) types. (6) sacral tumors were segmental on sagittal MR images. Conclusion MRI is superior to CT and plain X ray in assessing classification, segment and sacral pores and the like, so MRI is very important to the diagnosis and the differential diagnosis of the sacral tumors.

Objective To explore the musculoskeletal MR findings in dermatomyositis and to evaluate the role of MR in diagnosis of dermatomyositis. Methods Twenty patients with early dermatomyositis and 25 patients with active disease confirmed by pathology underwent T 1-weighted (SE 450/20), T 2-weighted (FSE 4000/100), and fat-suppressed MR images. MR findings in these 45 patients were analyzed. Results Within all the myositis, MR showed symmetrical slight high patchy signals on T 2-weighted and STIR images in the muscles of bilateral thighs, but the morphology of muscles appeared normal in 26 patients, while limited high signals only appeared on STIR image in 19 patients. There was correlation between serum muscle enzymes and the signal intensity as well as affected field of myositis. The myositis often affected gluteus and the external lateral muscles in the lower part of thighs. Inflammatory changes in the subcutaneous fat in 18 patients with active dermatomyositis were the severe appearance of the disease. Inflammatory fascia in 17 patients was found in both early and active cases. 5 patients had skin damage. Conclusion MR features of dermatomyositis are multiple myositis, fascia and subcutaneous inflammation, with the latter being an appearance of severe period of the disease. Early affected location of dermatomyositis is gluteus and the external lateral muscles in the lower part of thighs. MR is an efficient examination and STIR is a sensitive sequence in the diagnosis of dermatomyositis.

Objective To improve the diagnostic accuracy by analyzing the CT features of primary hepatic sarcoma.Methods The CT findings of 6 cases with primary hepatic sarcoma confirmed by histopathology were analyzed retrospectively,including primary hepatic angiosarcoma 2 cases,and epithelioid hemangioendothelioma,primary hepatic lymphoma,alveolar soft-part sarcoma,undif-ferentiated embryonal sarcoma,1 case each.Results Primary hepatic sarcoma appeared as multiple nodules with heterogeneous and progressive enhencement in one case,and a dominant mass with multiple satellite nodules in another case.Epithelioid hemangioendo-thelioma displayed as multifocal hepatic disease involving both liver lobes,more than half of the lesions were peripheral and extended to the liver margin.Primary hepatic lymphoma demonstrated as an ill-defined low-density lesion with irregular ring enhancement. Alveolar soft-part sarcoma presented as a well-defined low-density lesion with obviously heterogeneous enhancement in arterial phase.Undifferentiated embryonal sarcoma appeared as a huge cystic lesion with slightly margin enhancement.Conclusion The CT findings of primary hepatic sarcoma are associated with the pathological types,combining clinical symptoms with typical CT features are helpful to the diagnosis.The ultimate diagnosis relies on pathology and immune histochemistry.

Objective To evaluate mono-and bi-exponential decay models in the diagnosis of hepatocellular carcinoma (HCC). Methods 28 patients with HCC who underwent conventional MRI imaging and diffusion-weighted imaging were collected,and all the HCC lesions were proved by operation pathology.The ADC values in mono-exponential decay model and ADCst ,ADCslow , ADCfast and ffast of the lesions in bi-exponential decay model were measured through the reconstruction of ADCmap ,ADCslow map, ADCfast map and fraction of fast ADC at a workstation.The relationships between the ADC values with low,medium and high b-val-ues and different differentiation degrees of HCC were analyzed.Moreover,the relationships between the ADCst ,ADCslow ,ADCfast , ffast values and HCC defferentiation grades were also explored.Results Significant differences in ADC value were found among differ-ent degrees of HCC differentiation in middle and high b-value groups (P <0.05).A positive correlation was found between the ADC value and the degree of HCC differentiation in middle (r=0.377,P <0.01)and high b-value group (r =0.81 5,P <0.01).There were no significant differences in ADC value among the different degrees of HCC differentiation in low b-value group.There were significant differences in the values of ADCst ,ADCslow and ADCfast among different degrees of HCC differentiation.Significant posi-tive correlations were found between the values of ADCst ,ADCslow and ADCfast and the degree of differentiation (P <0.01).There were no significant differences in the values of ffast among different degrees of HCC differentiation.Conclusion ADC value in mono-exponential decay model plays a potential role in the diagnosis of different differentiation degree of HCC with a b value ≥400 s/mm2 .Furthermore,the parameters in bi-exponential decay model,especially the values of ADCst ,ADCslow and ADCfast ,can provide new and unique information in the distinction of different degrees of HCC differentiation.

Objective To observe the preliminary effects of the treatment for early non-traumatic osteonecrosis of the femoral head with Madopar. Methods Thirty-one patients with 48 hips of early stage (Ficat Ⅰ,Ⅱ) non-traumatic necrosis of the femoral head were treated with oral administration of Madopar since 2002. The disease was associated with consumption of alcohol in 16 cases with 27 hips; use of steroids in 10 cases with 13 hips; both consumption of alcohol and use of steroids in 2 cases with 4 hips; the remaining 3 cases, the condition was idiopathic. According to the criteria of Ficat et al., there were 4 hips in stage Ⅰ; 40 in stage Ⅱa and 4 in stage Ⅱb. Eighteen patients had received madopar for 10-28 months; 13 patients had been receiving the drug until now. Follow-up examinations were made by radiography, MRI and Charnley modified Merle d'Aubigne score. Results All patients were followed up for 12-84 months (average 27.8 months). The clinical symptoms improved in all cases. X-ray films showed that the bone density increased in nearly all the femoral heads, and 68.75%(33/48) of them maintained their shapes. The follow-up MRI showed their necrotic indices had decreased. The rate of clinical satisfaction was 91.67%(44/48), and the successful rate of treatment was 72.92%(35/48), and the collapse rate of early stage necrosis of the femoral head is 27.08%(13/48). Conclusion The preliminary results showed that madopar could prevent or delay collapse of the femoral head in early stage of osteonecrosis.

Objective To investigate the brain activation map during substraction and multiplication tasks in health adults.Methods 13 volunteers were undergone two tests of substraction and multiplication in the form of block-design.The fMRI data were analyzed by SPM99 software with statistic t-test to generate the activation map.Results In substraction ,the left middle frontal gyre(MFG),inferior frontal gyre(IFG),superior parietal lobule(SPL),inferior parietal lobule(IPL),angular gyre(AG),superior temporal gyre(STG),the right MFG,SPL,IPL , bilateral visual association cortex and cerebellum were activated.In multiplication , the left superior frontal gyre(SFG),MFG,IFG,SPL,AG,the right SPL,precentral gyre(PCG) and bilateral visual association cortex were activated.Conclusion (1)The bilateral prefrontal areas,parietal cortex and occipito-temporal areas are involved in calculation and have the function of working memory ,numerial manipulation and visua-space attention;(2)The cerebellum is involved in cognitive arithmetic.

Objective To investigate the diagnostic value of the early slope value of enhancement in differentiating benign from malignant musculoskeletal masses.Methods Dynamic contrast-enhanced gradient-recalled acquisition in the steady state imaging(GRASS) was performed to evaluate 36 musculoskeletal masses(18 malignant,18 benign).The difference of the early slope value of enhancement was analysed and compared between benign lesions and malignant ones.Using ROC curve plotting obtained the best decisive threshold.Spearman rank correlation analysis was used to determine the relation between slope and microvessel density of tumor tissues.Results The average early slope value of enhancement was (4.33?2.70)% per second (range 0.97%～10.50% per second)for malignant lesions,and was (1.46?0.97)% per second(range 0.37%～3.86% per second)for benign ones.There was an apparent statistical significance between benign and malignant tumors(?

Objective To summarize radiographic manifestations of granulocytic sarcoma (GS),in order to investigate its radio-graphic feature.Methods Nine patients of GS confirmed by surgery pathology and immunohistochemistry were collected.There were four cases underwent CT scan,2 underwent MRI,3 underwent CT and MRI meanwhile.Results There were 4 cases in the lymph nodes,4 cases in the bone,1 case in the enterocoelia.The density of enlarged lymph node was inhomogeneous,and smaller lymph node was homogeneous density,both enhanced obviously.The density or intensity of the lesions occurred in the canalis verteb-ralis and paravertebra was also homogeneous,slightly enhanced,with bone and medulla ossea invasion.Lesions in the enterocoelia was inhomogeneous desity with clear boundary,enhanced inhomogeneously.Conclusion GS is a rare extramedullary malignant tumor composed of immature myeloid cells.CT and MRI can provide a certain diagnostic value.The perplexity in diagnosing such lesions highlighted the need of careful interpretation of all clinacal,radiographic,histopathological and immunochistochemical details as it is one of the most frequently misdiagnosed disorder.

Objective To analyze the characteristics of dynamic contrast enhanced MR imaging (DCE-MRI)in prostate cancer (PCa)at 3.0T,and to evaluate the diagnostic value of DCE-MRI.Methods 85 patients with suepected PCa received conventional MRI and DCE-MRI.The signal intense-time (SI-T)curve was analyzed.Then the time to maximum (Tmax),the maximum degree of enhancement (STmax%),and the rate of enhancement (Rmax)were calculated.The differences of styles of SI-T curve and the parameters between the positive and negative group were compared respectively.Results 59 cases of PCa were proved by biopsy,and there was no evidence of tumor in 26 cases.507 zones had histopathological results with 250 zones in positive group and 257 zones in negative group .The most common style of SI-T curve in positive group was rapidly ascending followed with descending curve,the most common style of SI-T curve in negative group was persistent ascending curve and plateau curve.The mean values of Tmax,SImax%,Rmax were (69.49±22.53)s,1.74±0.43,7.83±3.80 in positive group respectively,while (175.61±52.64)s,1.05±0.35,1.86±1.10 in negative group respectively,there were statistically significant differences between the two groups(t =-24.24,1 6.34,1 7.75,P <0.01)respectively. The mean values of Tmax,SImax% ,Rmax were (8 9 .1 9 ± 3 1 .7 2 )s,1 .5 8 ± 0 .4 6 ,5 .2 1 ± 3 .3 4 in the low-risk group (Gleason score 2 - 6 )respectively,while (64.25±14.68)s,1.76±0.43,8.25±3.70 in the high-risk group (Gleason score 7-10)respectively, there were statistically significant differences between them(t = 7.09,-8.74,- 7.83,P <0.01).Conclusion 3.0T DCE-MRI has great value in the diagnosis of PCa.

Objective To explore the CT characteristics of primary pulmonary synovial sarcoma (PPSS)to improve the understanding of the disease.Methods The clinical,imaging and pathological data of 5 patients with PPSS confirmed by operation and pathology was analyzed retrospectively.4 patients underwent enhanced CT scan,and 1 patient underwent plain CT scan.STY-SSX fusion genes of 3 patients were detected by reverse transcriptase-polymerase chain reaction (RT-PCR).Results All the lesions were located in the upper lobe of the lung.Most lesions showed as round-like heterogeneous solid masses with clear edge,3 lesions showed heterogeneous enhancement,and 2 lesions showed circular enhancement with obviously enhanced parenchyma.1 lesion was with calcification,3 lesions were with ipsilateral pleural effusion,and mediastinal lymph nodes metastasis was seen in 1 case.The immunohistochemical results showed that the expressions of Vim,CD56,CD99,Bcl-2 and Ki-67 were positive.Only 1 case was EMA individually positive.SYT-SSX gene was detected in 3 cases.Conclusion The imaging findings of PPSS are relatively specific,the diagnosis mainly relies on pathological, immunohistochemical examination and SYT-SSX detection.