Objective　To evaluate the value of CT MRI in diagnosing skull base chondromas.Methods　8 cases of skull base chondromas were analyzed with etiology,pathology,imaging fetures and differential diagnosis.5 cases were female,3 cases were male,age ranged from 25 to 48 years.The clinical presentation of 8 cases of skull base chondromas had neurologic syndrome.And 3 cases were examined with CT,MR imaging ,4 cases with MR imaging,1 case with CT scanning.Results　In this series of 8 chondromas,3 located in the cavernous sinus,2 in the clival region,2 in the region of jugular foramen,1 in the frontal cranial fossa.Intratumoral calcification was found in 4 cases with CT examination.Heterogeneous enhancement was found in 4 cases with CT examination.The margin of chondromas on CT was well defined.Conclusion　CT have a very important diagnosis values for detecting tumors on chondromas.MRI is superior to CT for delineating the growth style of the tumor and its relationship to the surrounding anatomic structures.

Objective　To study the scan technique that can completely demonstrate the structures of middle-inner ear.Methods　Ninety volunteers underwent 30° axial and 105° coronal HRCT scan.The manifestations of the ministructures of middle-inner ear were observed and their demonstration rate was calculated.The demonstration of different structures of middle-inner ear was evaluated and compared on HRCT.Results　(1)The scan planes of 30° axial and 105° coronal were correspondent to some structures of middle-inner ear and could completely demonstrate them.(2)30° axial and 105° coronal HRCT scan had their own advantages respectively in demonstrating the structures of middle-inner ear.Conclusion　The technique of 30° axial and 105° coronal HRCT scan of middle-inner ear is useful in demonstrating the structures,including the nerve,joint,ligament etc and the relationship among them.

Objective　To define the range of the normal values of MRI signals of hippocampal formation(HPF) for the diagnosis of early stage Alzheimer's disease and hippocampal sclerosis.Methods　MRI signals of 254 normal adults were measured on the transverse section.Results　HPF signal intensities were:T1 relaxation times,629±73 ms;T2 relaxation times,83±5.5 ms;and proton density value,5978±651.The T2 value range(χ±2S)was 72～94 ms,and mean 83 ms.T2 value greater than 104 ms will be associated with evidence of hippocampal pathologic changes.The mixed signal intensity of T2WI(30,60,120)were:3907±407,2657±347,1288±174.The signal intensity ratios of T2WI were:1.02,1.07,1.13.Conclusion　As for the histological features of temporal lobe cortex and HPF,T1relaxation times and proton density values are matched but T2 relaxation times of HPF are relatively longer.

Objective To discuss the value of hypotonic-MRCP combined with LAVA dynamic contrast-enhanced scan in diagnosis of duodenal tumor.Methods Five patients with duodenal adenocarcinomas confirmed by pathology were involved in this study.All cases underwent plain MRI and hypotonic-MRCP and LAVA dynamic contrast-enhanced scans.Results 4 of 5 cases were correctly diagnosed with MR imaging.Imaging signs included:the cavum of descending duodenum appeared as asymmetrical stenosis,masses with soft tissue signal intensity connecting the intestinal wall with wide base,the intestinal wall stiff,the intestinal mucosa destruction.The lesions would be slightly-moderately enhanced at LAVA dynamic enhancement scanning.Conclusion Hypotonic-MRCP combined with LAVA dynamic contrast-enhanced scan can display the direct and indirect sign of duodenal tumors,which was effective in identifying the circumscription of the tumor and its extension.

Objective To evaluate the diagnostic value of enlargement of the anterior space of the right branch of portal vein in early cirrhosis.Methods 37 cases with early cirrhosis and 42 cases with type B hepatitis proved by pathology as well as 40 health cases underwent MDCT examinations.The width of the anterior space of right branch of portal vein(RBPV)and the diameters of RBPV in each group were measured on CT imaging,then the results were analysed comparatively.Results The width of anterior space of RBPV and the diameters of RBPV were(5.5±2.4)mm and(11.84±1.91)mm in health group,(13.6±5.8)mm and(12.36±61.97)mm in early cirrhosis group,(5.7±3.1)mm and(12.13±1.89)mm in type B hepatitis group,respectively.There were significant differences in the width of the anterior space of RBPV between three groups(P＜0.0001).However,there were not significant differences in the width of RBPV among these three groups(P＞0.05).While,there were significant differences of the width of the anterior space of RBPV and the diameters of the RBPV between normal control and type B hepatitis(P＞0.05).Conclusion CT sign of the anterior space of RBPV increased is of important value in diagnosis of early cirrhosis.

Objective To explore the value of the 64-slice spiral CT angiography(SCTA)in diagnosis of aortic disease.Methods 32 cases with aortic diseases confirmed by operation underwent 64-slice spiral CT enhanced scan,raw data were dealed with multiplanar reformation(MPR),curved plannar reformation(CPR),maximum intensity projection(MIP),volume rendering(VR)and advantage vessel analysis(AVA).Results The aortic disease in 32 cases included aortic dissection in 16 cases,pseudoaneurysm in 7 cases,true aneurysm in 4 cases,narrowing of the aortic arch in 3 cases and amputation of aortic arch in 2 cases.The endometrial break and mural thrombus better showed with MPR and the detecting rat of intimal flake and the initial break was 81%(13/16),while for the periphery thrombosis in 7 cases with pseudoaneurysm,the detecting rate was 100%(7/7).The showing rate for displaying the whole with CR was 100%(32/32).In showing calcification and accurate of vessels with MIP,the detecting rate was 84%(27/32).The showing rate of the extent of the disease and the relationship between peripheral vascular was 100%(32/32).AVA was of significance in the measurement of vascular diameter and vascular cross-sectional area,the showing rate was 44%(14/32).Conclusion 64-slice spiral CT angiography is of significance in diagnosing aortic diseases.

Objective To investigate imaging findings of lung injury after seawater drowning.Methods The imaging data in 12 cases with seawater drowning treated in our hospital in the past 8 years were analyzed retrospectively.Results After 2 to 12 hours of leaving the water,the initial chest X-ray examinations or CT scans were taken.The initial X-ray films displayed the lung markings increase,the small patch shadows or wide distribution patch shadows.CT showd large ground-glass density,diffuse patchy or flocculus shadows and different degress of emphysema in bilateral lung.Most of the foci were absorbed obviously in 1 to 3 days.In 1 case,the focus formed pulmonary abscess later.Conclusion X-ray and CT examinations can clearly show the severity and changes of lung damage in seawater submersion victims,and that can provide important informations for clinical diagnosis and treatment.

Objective To study the correlation between morphological characteristics of coronary artery calcified plaques and luminal stenosis of local coronary artery segments with 64-slice computed tomography.Methods One hundred and eleven patients who had undergone 64-slice computed tomographic coronary angiography(CTCA)and conventional coronary angiography(CAG)were retrospectively analyzed.The calcified plaques were classified as punctate,nodular,strip-like and nubbly in long-axis view of coronary artery lumen,and were classified as crescent,semilunar,round moon and circinate in short-axis view.The morphologic characteristics of these calcified plaques on CTCA were retrospectively analyzed and compared with luminal stenosis of CAG results.Results Among 528 calcified coronary segments which were analyzed in 111 patients,there were 383(72.5%)punctate calcified plaque segments and 145(27.5%)of non-punctate plaques.There were 34(23.4%,34/145)non-punctate calcified plaques which caused severe stenosis(≥75%),including 4(11.8%)nodular,8(23.5%)stripe-like and 22(64.7%)nubbly calcified plaques on the long-axis view,and 0(0.0%)cresent,8(23.5%)semilunar,18(52.9%)round moon and 8(23.5%)circinate calcified plaques on the short-axis view.The ratios of different morphological coronary artery calcifications which caused severe stenoses were significantly different with each other(all P＜0.01).Conclusion Different figures of coronary artery calcified plaques demonstrate different degrees of stenoses of local coronary artery lumen.Severe stenoses were mostly caused by nubbly calcified plaque on long-axis view,round moon and circinate calcified plaque on short-axis view.

Objective To study the relationship between the changes of diffusion tensor imaging(DTI)and diffusion tensor tractography(DTT)of optic radiation and the defect of visual field.Methods DTI and DTT were performed in 37 patients with invasion of the optic radiation by intracranial lesions and in 20 normal control group at 3.0T MR scanner,the visual fields of all cases were examined.The relativity between FA values,ADC values and mean sensitivity(MS)values,mean defect(MD)values of visual field and the relativity between the morphological change of optic radiation and the defect of visual field were analysed.Results In comparison with control group,FA values decreased and ADC values increased in subject group,there were statistically significant differences(P＜0.001)between them.In disordered group,FA values were positive correlation with MS values(r=0.718)and negative correlation with MD values(r=-0.694);ADC values were negative correlation with MS values(r=-0.625)and positive correlation with MD values(r=0.538).DTT showed that the ventral tracts of optic radiation were damaged which oppeared as the defect of ditto quadrant of bilateral field vision in 9 cases,the dorsal tracts and the lateral tracts of optic radiation were damaged which appeared as the defect of inferior quadrant of bilateral field vision in 7 cases,the optic radiations were damaged extensively that caused symmetric or asymmetric congruous hemianopia of bilateral field vision in 21 cases.Conclusion DTI and DTT of optic radiation are intimately correlated with the examined results of visual field,it will be a objective index to extimate the function and the morphological changes of optic radiation.

Objective To study the characteristics of MR imaging and proton MR spectrscopy(~1H MRS)of stroke-like lesions in MELAS.Methods Clinical,MR imaging and proton spectroscopic findings of stroke-like lesions in 7 patients with confirmed MELAS were analyzed retrospectively.Results A total of 12 MR investigations had been performed in 7 patients.Stroke-like lesions showed by MR imaging included superacute in 12,acute in 12,subacute in 10 and chronic stage in 6.Early stroke-like lesions were demonstrated as focal edematous foci mainly involved cortex/subcotical areas of occipital,temporal and parietal lobes.At MR diffusion imaging,stroke-like lesions in the superacute(＜3 days)stage were showed as well-circumscribed lesions with high signal intensities for cytotoxic edema.During the acute(4～7 days),sub-acute(2～4 weeks)and chronic(＞4 weeks)stages,the lesions gradually expanded,and became blur,and presented with vasogenic edema mainly.Proton spectroscopy showed a prominently elevated lactate,varied decrease of NAA concentration and other brain motabolites in the stroke-like lesions early after onset,and depicted gradual decrease of lactate level and partial recovery of NAA concentration subsequently.Conclusion Stroke-like lesions in MELAS mainly involve the cerebral cortex and subcortical areas,in which cytotoxic edema appears early but for a short period.In ~1H MRS,the lesions are characterized by a double lactate peak with decrease of NAA concentration.