Objective To investigate the imaging manifestation of immature teratoma.Methods Imaging features of 9 cases of immature teratoma.confirmed pathologically were retrospective analysed.Results All 9 cases were male,age ranging from 1 to 38 years,mean age 1 9.5 years,AFP increased varying degrees in six cases .(1)3 cases (mean age 25.5 years)located in the anterior mediastinum which CT characteristics included the following features:lesions were projecting to one side,with irregular shape,obvi-ous necrosis,mild enhancement,wrap or oppression the blood vessels,one case with superior vena cava and head arm vein tumor em-boli and mediastinal lymph node metastasis.(2)6 cases (mean age 9.5 years)located in the pineal region and tricorn region,which MR finding were as following :cystic or solid placeholders,tow cases with small calcification or fat,solid part and the capsule wall enhancement significantly,4 cases with nodular enhancement.Conclusion Immature teratoma tends to occur in the middle struc-ture,and appears in children and young adults frequently,necrosis and cystic changes are seen commonly.CT and MR are of high val-ue in diagnosing immature teratoma.

Objective To explore the scanning technology of head-neck-coronaryone-stop-shopCT angiography using 256-slice iCT and complete image quality analysis.Methods 106 consecutive patients underwent 256-slice iCT head-neck-coronaryone-stop-shop CT angiography.According to the average heart rate,patients were divided into three groups,the 1ow heart rate group with the average heart rate ranged from 40 to 60,medium heart rate group with heart rate from 60 to 80 beats per minute and high heart rate group with heart rate more than 80 beats per minute.The volume rendering (VR),maximum intensity projection (MIP), multi-planar reformation (MPR)and curved planar reconstruction (CPR)were employed for three-dimensional reconstruction after the original image reached to the iCT post-processing workstation.The image quality of head-neck artery and coronary artery were assessed by two senior radiologists individually .Results The image quality scores in the three groups show statistic significance (F=14.886 , P =0.000).The difference between low heart rate group and medium heart rate group show statistic significance (P =0.031).The difference between low heart rate group and high heart rate group was statistical significant (P = 0.026 ).There was no statistic difference between medium heart rate group and high heart group.The excellent rates of coronary artery image quality reached to 100%,96.6%,92.6% in low,medium and high heart rate group respectively.The rates of excellent about head-neck vascular im-age quality in the three groups reached to 100%.Conclusion 256-slice iCT head-neck-coronaryone-stop-shopCT angiography can obtain satisfactory image.The image quality does not decrease in patients with high heat rate.