Objective To evaluate CT features of hepatic abscess caused by different etiologies.Methods CT appearances and clinical data of hepatic abscesses were retrospectively studied in 54 cases.Results There appeared low density lesions in hepatic abscess.Target sign,cluster sign and air in the cavity were special CT manifestations of hepatic abscess.Abscess caused by different etiologies had different features,which included infection by blood stream or bile duct abnormalities,amebic liver abscess,and hepatocellular carcinoma complicated with suppurative infection after treated with TAE.Conclusion The CT manifestations of hepatic abscess were characteristic.These manifestations were helpful in diagnosing hepatic abscess not only in location but also in nature and etiology.

Objective To evaluate the effect of the percutaneous lumbar puncture to treat sciatica caused by lumbar disc herniation.Methods 75 cases of lumbar disc herniation with significant clinical signs were confirmed by CT scan. The technique of the percutaneous lumbar puncture led the needle to approach nerve root and injected medicine diffusing into extraduramater, and then relieved the symptom of sciatica. Results The rate of success of percutaneous lumbar puncture guided by CT reached to 100%. After two weeks of follow up, the symptom of pain was obviously improved and disappeared in 63.3% cases. There were 23.0% cases needed a second proceduse, and no change was obsesved in 9.3% cases.Conclusions The percutaneous lumbar puncture guided by CT to treat sciatica resulted from lumbar disc herniation is one of the safe ,reliable,effective new methods with no complication. The long term effectiveness is still in need of investigation.