Objective To observe the relationship between visual-spatial perception impairment and the characteristics of asymptomatic cerebral infarction (ACI). Methods After evaluating the cognitive impairment of 112 patients with ACI using the Revised Visual Retention Test (VRT), we compared the result of VRT test among different groups grouped by number, size and location of the cerebral infarction. Results The total score of the patients with ACI with correct answers in VRT was significantly lower than that of the controls (14.5?3.2 vs 22.8?3.3, P

Objective To study the MR imaging features of intracranial subependymomas and to improve the knowledge more about it. Methods The imaging features of intracranial subependymomas in 17 cases proved pathologically were retrospectively analyzed, among which 11 cases were male and 6 cases were female, 16 cases had MR images and 1 case only had CT images.Results MR appearances of intracranial subependymomas were as follows :16 cases were all hyperintense relative to the normal grey matter on T2-weighted images and hypointense or isointense on T1-weighted images. 12 cases showed no enhancement or minimal enhancement after Gd-DTPA administration . 9 of 16 cases were located in lateral ventricle, 2 were in septum pellucidum, and the rest 5 were in fourth ventricle ,third ventricle ,prepontine cistern, right CPA and chiasmatic cistern respectively. In one case , CT showed isodensity and was enhanced in CE-CT,the lesion was situated in fourth ventricle. In all 17 cases, 11 were accompanied with microcystic structures. Conclusion Intracranial subependymomas are best delineated by MR imaging. The diagnosis of intracranial subependymomas should be considered when above findings are confronted.

Objective To develop a rapid method for construction of RNAi vector.Methods After inversely inserting the U6 and H1 polymerase Ⅲ promoters into the pBluescriptⅡ backbone vector,only with two short reverse complementary oligo nucleotides,the RNAi vector with one interference cassette could be constructed.Using two isoaudamers MunⅠ and EcoRⅠ with sticky ends,several cassettes could be fused together to form the ultimate multiple-site targeting RNAi vector.Using this method,we constructed RNAi vectors targeting green fluorescent protein(GFP) and firefly luciferase(LUC) gene separately or both for the test of knock down property of these vectors.Results Constructed single and two site targeting RNAi vectors got desirable knockdown effects,in which single site targeting vector could get about 90 percent knock down efficiency whereas two site targeting vector reached about 87.5 percent knock down efficiency either.Conclusion Our RNAi vector construction strategy is efficient and time-saving so that it can be used for knocking down several genes simultaneously in the same cell.

Objective To establish a new automatic lung segmentation method in order to deal with the omission of pleural nodules and pulmonary vessels. Methods Lung parenchyma were extracted from chest CT images with the inversed operation of 2D region growing and connected area classification, then the contours and locating the contour points were traced with scan line searching. Finally, the parameters of lung contour points were analyzed to locate the contours distorted by nodules, and curve spline was used to correct distorted contours. Results The experimental results of many sets of CT images verified that the technique proposed was effective. The comparison with other contour correction algorithm verified that line searching contour correction was superior. Conclusion The proposed algorithm includes tumors in the segment results, and confirms the integrality, veracity, real-time quality of this auto-segmentation method.

Objective To examine the intracranial lesions before and after operation by functional MRI with BOLD technique, and to map the brain activation images of the patients on general MR images. Methods Thirty one patients had lesions involving the frontal and/or parietal lobes in one side of the cerebral hemispheres, and the lesions included 29 tumors (11 gliomas; 13 metastases; 5 meningiomas) and 2 infections. MSEPI technique was performed with four scan planar parallel AC PC. During each scan series, the patients were asked to perform repetitive finger thumb opposition movement in the same period of active and rest duration. All the scanning data were transferred to a workstation and dealt with statistical method. The patients had been examined again by the same sequence protocol postoperatively, and the fMRI images were analyzed and compared with that of the preoperation fMRI. Results The motor cortex of both cerebral hemisphere was asymmetrical, and the border between the motor cortex and lesions could be clearly identified in all of the patients preoperatively. After operation, both sites of the motor cortex were nearly replaced. Conclusion fMRI was very useful in evaluating the surgical planning and the prognosis of the patients.

Objective To study the imaging characters of spinal teratomas.Methods 10 cases of spinal teratomas were analyzed with clinical and radiography. 8 cases intramedullary, 2 cases extramedullary. 10 cases had MR examination. Results The location of spinal teratomas in 5 cases was in lumbar, 3 cases in thorax, 1 case in thoracolumbar, 1 case in cervical. 7 cases were multicyst type, 3 cases were singlecyst type. 10 cases of MR image showed mix signal intensity. The contrast enhancement T 1WI with fat saturation presented disappear fat signal of spinal teratomas. The teratomas heterogeneous enhancement was found in 10 cases with MR examination. 3 cases lumbosacral area of spinal teratomas united tethercord. Conclusion Neuroradiological features of spinal teratomas has specific manifestation. The T 1WI fat saturation scan is a availability nicety method for spinal teratomas.

Objective To study and compare the clinical and MR imaging characteristics of common intracranial ring enhanced lesions.Methods MR imaging studies of 65 intracranial ring enhanced lesions were reviewed retrospectively. The lesions included 17 glioblastomas, 17 metastasises, 12 brain abscesses, 8 acoustic neurinomas, 7 craniopharyngiomas, 3 neurocysticercosises, 1 malignant lymphoma. All cases were confirmed by surgery and pathology. Results The ring enhancement of tumors presented heterogenous thickness of thick walls and irregular forms. Among them, the highly malignant tumors appeared very obviously heterogeneous thickness of the walls, especially the inner walls were uneven and coarse. While the ring enhancement of the non-tumor lesions usually were of homogeneous thickness of the walls, regular shapes and smooth inner walls. Conclusion The different patterns of intracranial ring enhanced lesions on MR can supply important diagnostic information. Combining the patients' history, age, location and the information of magnetic resonance imaging, we may make correct diagnosis.

Objective To evaluate and compare the diagnostic value of digital mammography-guided biopsy with mammography for early-stage breast cancer. Methods 68 of 156 foci(from 148 cases) with diameter≤2.0 cm from 2850 mammographic cases during Nov.2001 and Sep.2002,were urdestaken mammography-guided biopsy and then compared the coherence of the biopsy and mammographic results with the pathology. Results The obviously accuracy of mammography-guided biopsy is obviously superior to the mammography(P

Objective To study the imaging findings of cerebral venous sinus occlusion and to improve the knowledge of this disease.Methods CT,MRI and DSA data in thirty six cases with cerebral venous sinous occlusion were retrospectively reviewed.There were 15 male and 21 female,ranged in age from 23 to 59 years old.Results On T_1WI and T_2WI,abnormal signals in cerebral parenchyma were found in 26 cases,of that there were brain hemorrhage with abnromal long T_1 and long T_2 signal in 16 cases,only abnromal long T_1 and long T_2 signal in 6 cases,cerebral ventrical enlargment in 4 cases and brain swelling in 4 cases.The abnormal venous enhancement was found in 25 cases on contrast-enhanced MRI.On CT scan,low density in cerebral parenchyma was found in 10 cases,it might be edema or ischemia,astime goes by,the density of cerebral venous sinus became slightly high density to isodensity.DSA showed dural sinus occlusion includingsuperior sagittal sinus in 15 cases,transverse sinus in 8 cases,sigmoid sinus in 7 cases,straight sinus in 4 cases and inferior sagittal sinus in 2 cases.Conclusion The venous sinus occlusive disease is distinctively different from arterial occlusive disease.CT and MR imaging is very important in diagnosing the cerebral venous sinus occlusive disease,but DSA is still the gold standard.