Objective To study the changes of magnetic resonance diffusion weighted imaging(DWI) in acute cerebral ischemia and reperfusion injury. Methods Adult healthy NewZeadand rabbits(103 cases) were used to established middle cerebral ischemia and reperfusion(MCAO/R) model by intraluminal thread technique,and 58 successful models were randomly divided into permanent ischemic group(30 cases) which further divided into ischemic 1 h,3 h,6 h,12 h,24 h,48 h groups consisting 5 cases and ischemic reperfusion group 28 cases which further divided into reperfusion 0h,2h,5h,11h,23h,47h groups consisting 5,5,5,4,5,4 cases respectively.Another 10 rabbits were regarded as ischemic contrast(5 cases) and reperfusion contrast(5 cases).The changes of hyper-intensity signal area on DWI and apparent diffusion coefficient(ADC) were measured in different groups Results 1.In ischemic group rabbits,the hyper-intensity signal area on DWI with declined ADC appeared at ischemic 1h.The hyper-intensity signal areas on DWI at different times were larger than that at ischemic 1h and unchanged at 24h.The mean ADC at different times declined at first and then gradually increased.2.In reperfusion group rabbits: compared with ischemic 1h,the hyper-intensity signal area on DWI reduced while ADC increased at reperfusion 2 and 5h,but the hyper-intensity signal area on DWI enlarged with ADC high at reperfusion 11h,then the hyper-intensity signal area on DWI enlarged with ADC reduced siginificantly at 23h and 47h.Conclusion The hyper-intensity signal area on DWI and the decreasing ADC in acute cerebral ischemia could be improved by early reperfusion,but the secondary decreasing ADC would be induced with continously reperfusion.

Objective To summarize and study the features of intracranial chondroma on CT and MRI imaging.Methods CT and MRI findings of ten cases of intracranial chondroma proved by surgery and pathology from 1994.1 to 2004.9 were retrospectively analyzed.Results Among 10 cases, 4 cases were located at the skull base, 4 cases at convexity, 1 case at the region of falx cerebri, and 1 case within the brain parenchyma.CT scans showed obvious calcification and clear border of the tumors in 10 cases, mixed attenuation in 9 cases, and adjacent bone invasion in 5 cases.4 cases of MRI scans showed hypointense signal on T1 and T2-weighted images in calcified element of the tumor, intermediate to hypointense signal intensity on T1-weighted image, and hyperintense signal intensity on T2-weighted image in parenchyma of the tumor.4 cases of CT scans showed slightly enhancement.Conclusion Intracranial chondroma are often originated from synchondrosis of the skull base, convexity of brain and region of falx cerebri. Obvious calcification may be seen in most cases. Slightly enhancement and marked delayed contrast enhancement were characteristic. The accurate diagnosis still depends on pathology.

Objective To study the value of the changes of signal intensity at the jugular bulb in diagnosing sigmoid sinus thrombosis.Methods MR imaging examinations were performed in 27 cases with cerebral venous sinus thrombosis(transverse and sigmoid sinuses).The signal intensity at the jugular bulb was evaluated in comparison with that in 20 healthy persons,and the results were dealed with Wilcoxon rank sum test statistically.Results In sigmoid sinus thrombosis,the signal intensity at ipsilateral jugular bulb was higher than that in healthy group(P

Objective To evaluate the value of diffusion-weighted imaging (DWI)in diagnosing the acute centrum ovale infarction, and also to investigate the pathogenesis of the infarction. Methods All 58 patients underwent conventional MRI and DWI scanning after symptoms’ onset. DWI findings were compared to the findings of T_1WI and T_2WI. Results The sensitivity and specificity in diagnosing the ischemia stroke were 96.4% and 98.8% within 7 days after onset. Of all the cases, 62.1% were associated with the cerebral large-vessel disease and emboligenic heart disease. Only 36.2% had a classic lacunar syndrome but 69.0% had more frequently an abrupt onset of symptoms. Conclusion DWI is of high accuracy for diagnosing centrum ovale infarction and detecting early infarction lesions which are difficult to be displayed in conventional MRI, and very helpful in differentiating the acute from non-acute lesions; symptomatic centrum ovale infarction is suggested to be associated with large-vessel and heart disease which should be distinguished from the lacunar infarcts.

Objective To discuss the method, therapeutic effect and safety of CT-guided 125I radioactive seed implantation for the treatment of cervical lymph node metastasis. Methods CT-guided 125I radioactive seed implantation was performed in 32 patients with pathologically proved cervical lymph node metastasis Results The local effective control rates of the cervical lymph node metastasis at one, 3, 6 and 12 months after the treatment were 81.3%(26/32), 84.4%(27/32), 93.7%(30/32) and 87.5%(28/32) respectively. Conclusion For the treatment of cervical lymph node metastasis, CT-guided 125I radioactive seed implantation is technically simple and clinically safe with reliable curative effect; this treatment is very effective in improving local tumor control rate.

Objective To explore the values of apparent diffusion coefficients (ADC) in staging the lesions of multiple sclerosis (MS) through analysing the differences of ADC in different types of lesions.Methods 137 lesions identified in 29 patients with MS,were characterized by their enhancement pattern on contrast-enhanced T1-weighted MR images and whether they were changing in appearance, size or signal.The lesions were classified into four groups:homogeneously enhancing lesions (HELs), ring-enhancing lesions (RELs), active nonenhancing lesions (ANELs), and inactive nonenhancing lesions (INELs).The mean ADC values for each type of lesions were calculated and compared.Results The ADC values for HELs, RELs, ANELs and INELs were (91.09±13.63)× 10 5 · m2 · s-1, (105.66±9.92) × 10-5 · m2 · s-1, (136.80±20.31) × 10-5 · m2 · s-1 and (127.46±13.65) ×10-5 · m2 · s-1.There were significant differences between the ADC values of any two groups in the four groups except the ADC values between ANELs and INELs.Conclusion ADC values are useful to differentiate each type of lesion,which can help stage the lesions of MS.

BACKGROUND: A middle cerebral artery occlusion and reperfusion(MCAO/R) model in rats with suture has been widely used in the researches of acute focal ischemic cerebral infarction, while the model in rabbits by the same method is relatively rare. Magnetic resonance diffusion weighted imaging (MR DWI) has been paid close attention recently for its sharp sensitivity of cerebral ischemia.OBJECTIVE: To establish rabbit models of MCAO/R by intraluminal thread, and study the characteristics of MR DWI after cerebral ischemia and reperfusion.DESIGN: Random controlled animal experiment.SETTING: Institute of Cerebrovascular Diseases, Affiliated Hospital of Qingdao University Medical College.MATERIALS: The experiment was accomplished at the Key Laboratory of Brain Diseases Prevention and Cure of Shandong Province from March to June in 2005. A total of 103 adult healthy New Zealand rabbits of either sex, 10-12 weeks old and 1.8-3.3 kg weight were provided by the Experimental Animal Center of Shandong Agricultural Academy (SCX20040013).They were bred at quiet, sanitary and dry conditions.METHODS: Animal groups: 103 rabbits were divided randomly into group A (n=53) and group B (n=50). The rabbits in group A were treated with suture of 0.51-0.55 mm as the diameter of thread, while group B was reassigned into B1 (0.46-0.50 mm), B2 (0.51-0.55 mm) and B3 (0.56-0.60 mm).The successful MCAO/R models in 57 cases were randomly divided into permanent ischemia group (n=30, ischemia 1, 3, 6, 12, 24 andl 48 hours, 5ones at each time point) and ischemic reperfusion group (n=27, reperfusion 0, 2 and 5 hours, 5 ones at each time point; reperfusion 11, 23 and 47hours, 4 ones at each time point). Another 10 rabbits receiving sham operations were regarded as contrasts for permanent ischemia group and ischemia reperfusion group, with 5 ones in each.MAIN OUTCOME MEASURES: The changes of hyperintensity area on DWI and apparent diffusion coefficient (ADC) were measured in permanent ischemia group and ischemic reperfusion group.RESULTS: The data of 57 successful model rabbits were involved in the result analysis.①The successful rate in group A (26 cases, 49.1%) was significantly lower than that in group B (31 cases, 62.0%).②In ischemia group:The hyperintensity area on DWI with declined ADC appeared at ischemia 1 hour. The hyperintensity areas on DWI at different times increased gradually from ischemia 1 hour and unchanged within 24 hours. The mean ADC at different times declined at first and then gradually increased.③In reperfusion group: Comparing with ischemia 1 hour, the hyperintensity area on DWI reduced while ADC increased at reperfusion 2 hours and 5 hours, and enlarged with ADC high at reperfusion 11 hours, then continued to enlarge with ADC reduced significantly at 23 hours and 47 hours.CONCLUSION: The diameter of thread tip and the inserting distance of thread are main factors for establishing successful MCAO/R models. The hyperintensity area on DWI and the decreasing ADC after acute cerebral ischemia can be improved by early reperfusion, but the secondary decreasing ADC may be induced by continuously reperfusion.

Objective To investigate the diagnostic value of CT and MRI in basal ganglia germinoma.Methods The clinical and imaging data in 1 7 patients with basal ganglia germinoma proved pathologically or clinically were analyzed retrospectively.Results All patients were male with an age rang from 8 to 18 years old and a mean age of 10.8 years.The most common symptom was hemi-paresis.Imaging features of the lesion were as follows:① usually irregular shape(11/17,64.7%)and cystic degeneration (10/17, 58.8%)without space-occupying effect and surrounding edema (12/17,70.6%);② isointensity on conventional MRI,hyperintensi-ty on DWI and hyperdensity on CT;15 patients (15/17,88.2%)with one or more than one appearances including multiple lesions, the lesion extending into surrounding structures and Waller degeneration.Conclusion Some clinical and imaging features of the basal ganglia germinoma are characteristic,and CT and MRI shows higher diagnostic value for the disease.

Objective To explore the features of leukoencephalopathy with cerebral calcifications and cysts (LCC) in clinic, radiology and pathology in order to improve skills in diagnosis. Methods Two female patients had CT and/or MRI scan, and case 2 had contrast enhancement MRI scan additionally. Both cases had blood biochemistry examinations including calcium, phosphorus and alkaline phosphatase et al. Case 2 had lumbar puncture and cerebrospinal fluid test. The major cystic lesion was surgically removed in both patients and offered a histopathological examination. Results CT scan reveaed diffuse calcifications in the bilateral basal ganglia, white matter of frontal lobe and/or dentate nuclei of cerebellum in both cases, and major cystic lesion in right frontal lobe (case 1) and the left parietal lobe (case 2). The rim of enhancement was observed in cystic lesion on MRI. Histopatbological examination revealed angiomatous rearrangements of the microvessels with fibroid, hyaline degeneration and haemosiderin deposits, brain tissue associated with areas of demyelinization, some Rosenthal fibers, gliosis, calcium deposits and hemorrhage, fibrinoid necrosis occurs in partial vessels associated with thrombogenesis and stenosis as changes in arteriolitis. Blood biochemistry examination showed normal. Cerebrospinal fluid test in case 2 showed increased intracranial pressure(350 mm H_2O,I mm H_2O =0. 0098 kPa). Conclusions The onset of LCC varies and occurs from early infancy to adult. The asymmetrical calcification is characteristic in LCC. Hemorrhage could be involved in the pathogenesis of cystic formation. LCC is characterized by a cerebral obliterative microangiopathy, both demyelinization and the edematous changes could probably result in white matter abnormalities on neuroimaging.

Objective To evaluate the manifestations and diagnostic value of CT enterography (CTE) in primary intestinal T-cell lymphoma (PITCL).Methods Eighteen patients with PITCL confirmed by pathology were reviewed retrospec tively.The characteristics of lesion site,amount of foci,pattern and degree of contrast enhancement,lymphadenopathy,involvement of other organs and complications were recorded.Results In all of the 18 patients with PITCL,multiple lesions were seen in 13 cases (13/18,72.22％),and solitary involvement was seen in 5 cases (5/18,27.78％).Twelve ca ses were located at jejunum/ileum,3 of them were also involved in the colon.Five cases were located only in the colon,and 1 in the duodenum.Six cases were complicated with intestinal perforation.The patients were categorized into 6 types according to the CT manifestation:infiltration type (n=7),diffuse jejunum mucosa ileum metaplasia type (n =3),luminal aneurismal dilatation type (n =3),polypoid mass type (n =2),mesentery type (n=1),mixed type (n =2).Conclusion CTE can clearly display the imaging of PITCL and it has high value for the diagnosis of PITCL.