Objective To research the reduction of computed radiography exposure.Methods By body-model computed radiography test,the relationship between X-ray exposure on the image plate to the latitude and sensitivity of the exposure data recognizer was investigated,from which the low-dose value of exposure was achieved.Results The low-dose value of the computed radiography was 22.5% of the average-dose.Conclusion The low-dose of computed radiography can be achieved.

Objective To improve the understanding of the vertebrobasilar dolichoectasia (VBD) by analyzing the MRA imaging features of VBD.Methods The data of 438 patients underwent MRA were analyzed in the study.The length and transverse deviation of the basilar arteries (BA) were measured for the diagnosis and classification of VBD.Of 438 patients, 342 patients were diagnosed as brain infarction (BI) by head MRI.All of the BI patients were divided into 2 groups (VBD and non-VBD) and the classifications of BI were compared between the two groups.Results Of 438 patients, 16 were diagnosed with VBD by MRA.According to the modality of VBD on MRA, VBD were classified into 4 types: S type, U type, L type and spiral type.Among the 16 patients, there were 7 patients with S type, 5 patients with U type, 3 patients with L type and 1 patient with spiral type.S type had the highest incidence and the mildest symptom.The incidence of VBD in BI patients was 3.98%, and the incidence of BI in VBD patients was 2.1 times greater than that of patients without VBD (P<0.05).Conclusion VBD can be classified into 4 types according to the MRA results.The clinical symptoms are varied with different imaging features, and VBD is closely related to the posterior circulation ischemia, especially brainstem infarction.

Objective To discuss and to compare the curative effects of interventional embolization with different embolic agents in treating giant hepatic cavernous hemangiomas. Methods From 2008 to 2010, a total of 30 cases with clinically proved hepatic cavernous hemangioma were treated with interventional embolization. According to the embolic agents used , the patients were divided into pingyangmycin-lipiodol emulsion mixed with sodium alginate microspheres group(PLE+KMG, group A, n=15) and pingyangmycin-lipiodol emulsion group (PLE, group B, n=15). CT scanning was performed one, 3, 6, 12 months after the treatment to evaluate the curative effect. Results The technical success rate was 100%in both groups. The mean PLE dose used in group A and B was (10.9 ± 5.2) ml and (11.4 ± 4.9) ml respectively, the difference between the two groups was not significant (P > 0.05). CT reexamination performed one, 3, 6 months after the treatment showed that a reduction in tumor volume over 50%in group A was seen in 9, 11 and 14 cases respectively, while in group B it was 0, 3 and 5 cases respectively (P <0.05). One week after the procedure, the degree of pain in patients of group A was more severe than that in patients of group B, the difference between the two groups was statistically significant (P < 0.05). Slight abnormal hepatic function was seen in some patients of both groups, which presented mainly as an elevation of aminotransferase, which returned to normal after symptomatic medication. Follow-up with questionnaire indicted that patients of group A were more satisfied with the treatment than the patients of group B. Conclusion Transhepatic infusion of pingyangmycin-lipiodol emulsion is a safe and effective treatment for giant cavernous hemangioma of the liver. Combination use of pingyangmycin-lipiodol emulsion and sodium alginate microspheres can obviously reduce the tumor size mainly in the first and the third month after the treatment, besides it produces instant clinical effect although the pain is more severe than in patients treated with pure pingyangmycin-lipiodol emulsion.

Objective To analyze MRI value in diagnosing liver abscess.Methods MRI findings of liver abscess confirmed by clinical and pathology in 29 patients were analyzed retrospectively.Results 17 patients were single lesion and 12 patients were multiple lesions,totally 58 liver abscesses.MR imaging showed cluster sign in 15 cases,abnormal hepatic segmental or lamellar signal in 22 cases,lace pattern and crest septum in 17 cases,target sign or double ring sign in 8 cases,abscess with gas in 3 cases and tissue crumb sediment inside of abscess in 3 cases.On contrast-enhanced scan in 10 cases,7 cases showed marginal enhancement and 5 cases showed honeycomb or grid enhancement.Conclusion MRI can preferably show the characteristics of liver abscesses,it is of important value in diagnosis.

0.05).Conclusion The chest low-dose computed radiography is valuable in the field of clinical diagnosis.

Objective To investigate the relationship between carotid arteriostenosis and atheromatous plaques with cerebral in-farction.Methods Cervical spiral CT angiography of 56 cases with cerebral infarction and 49 cases without cerebral infarction were retrospectively analysed .The difference between the two groups was compared with regard to the distribution ,nature of plaques and the degree of carotid artery stenosis.Results Of 56 patients with cerebral infarction,126 atheromatous plaques were detected in 42 patients,of which 39 were soft,34 were calcified,53 exhibited a combined nature of both calcified and soft plaque and 7 cases were plaque ulcerations (soft plaque and mixed plaque accounted for about 73%).Plaque location for carotid artery was in the bifurcation. 102 carotid arteries stenosis were found in 38 patients,which included mild stenosis in 29,moderate in 40,severe in 27 and occlusion in 6(moderate and severe stenosis accounted for about 65.7%).In the control group,28 plaques were detected in 1 1 cases,of which 6 were soft,13 were calcified and 9 exhibited a combined nature of both calcified and soft plaque.1 1 carotid arteries stenosis were found in 7 patients,included mild stenosis in 10,moderate in 1.A significant difference (P <0.05)in carotid arteriostenosis and ath-eromatous plaques between the two groups was found.Conclusion Carotid plaques and stenosis are important risk factors of cerebral infarction.Multi-slice spiral CT angiography(MSCTA)has important value in analysis of carotid artery stenosis and atheroderotic plaques.

Objective To analyze the plaque distribution of abdominal aorta and its branches by multislice spiral CT angiography (MSCTA).Methods 145 patients recommended to abdominal enhanced CT were randomly selected in this investigation,and divided into three groups according to their age,i.e.,young,middle and old-aged group.CTA was performed with the use of multiple planar reconstruction(MPR),volume rendering (VR)and vessel probe(VP)technology.Results 124 patients with atherosclerotic plaques of abdominal aorta and all its branch-vessels,the incidences of the three groups were 9.7%(14 cases),30.3%(44 cases)and 45.5%(66 cases)respectively(P <0.005).It showed that calcified plaques were detected in a total of 1 50 in 302 plaques of all the branch-vessels.230 plaques(76.2%)were detected in abdominal branch-vessels of grade 1,of which,the incidences of superior mesenteric artery plaques was the highest(32.4%).Of the 54 plaques(1 7.9%)detected in abdominal branch-vessels of grade 2,the incidence of splenic artery plaques was the highest(13.8%).In abdominal branch-vessels of grade 3,the plaques were mainly distributed in splen-ic lobial artery.The splenic artery plaques mainly spreaded in the middle segment,while other plaques were mostly in peristome and proximal segment of vessels.The incidences of plaques in the three branches were 47.6%(69 cases),1 5.2%(22 cases),and 9.0%(13 cases)respectively(P <0.005).Conclusion The incidences of atherosclerotic plaques are higher in the middle and aged people. The plaques of the three abdominal branch-vessels mainly distribute in the peristome and proximal segment,and are much likely to be detected in abdominal branch-vessels of grade 1.

Objective To investigate the risk factors and the influence of intravenous thrombolysis of acute cerebral infarction with cerebral microbleeds(CMBs)by SWI.Methods 1 64 patients with acute cerebral infarction were enrolled in this study.All pa-tients were scanned with routine MRI and SWI.According to the presence of CMBs on SWI,the patients were classified into two groups:CMBs group(73 cases)and non-CMBs group(91 cases).Past history was recorded and risk factors of CMBs were explored. 76 cases patients(including 35 cases of CMBs group and 41 cases of non-CMBs group)were treated by intravenous thrombolysis and rescanned with routine MRI and SWI to compare the changes in the number of CMBs and hemorrhage transformation 24 hours after thrombolysis.Results The difference age,hypertension,lacunar infarction and leukoaraiosis between the two groups were significant (P <0.05).The difference of CMBs and hemorrhagic transformation between the two groups treated by thrombolysis were not sig-nificant(P >0.05).Conclusion Acute cerebral infarction with CMBs are influenced by age,hypertension,lacunar infarction and leu-koaraiosis.Thrombolysis in acute cerebral infarction with CMBs can not augment the incidence of hemorrhagic transformation.