Background: CT scan of hepatic carcinoma after transarterial embolization with Lipiodol (LP-TAE) will be influenced. A comparative study was made between CT scan and hepatoarteriography in hepatic carcinomas fully filled with Lipiodol after TAE for the purpose of demonstrating the difference. Materials and Methods: 20 cases of hepatic carcinoma fully filled with Lipiodol after TAE 1 to 8 months, confirmed by CT scans. Hepatoarteriography were then done 1 to 14 days afterwards. The demonstration of the original and new foci were thus be compared respec- tively by these methods. Results: The original tumor lesions were all stable on CT scans and new tumor lesions were found in 5 cases. Three features were found in arteriographies of the original tumor lesions: (1) stable, no obvious tumor vessels and stain; (2) tumor vessels and stains confined within the LP accumulated areas; (3) largely increased lesions exceeding the LP accumulated areas; (3)largely increased lesions exceeding the LP accumulated areas. Also other three features were found in new tumor lesion: (1) multiple intrahepatic daughter nodules; (2)small arterioportal shunts; (3) new masses. Conclusion: (1) Although good results had been archieved, but the lesions were not stabe in many of them. Long interval follow-up and TAE were not suitable. (2) Stage-Ⅱ surgical resection should be taken cautiously. (3) New techniques of CT scan and superselective he- patic arteriography with high flow rate should be adopted to improve the accuracy rate of de- monstrating tumor lesion.

Objective To study the clinical value of colorectal carcinoma exa mination by comparison of different postprocessing techniques such as multiplana r reformation(MPR),CT virtual colonoscopy(CTVC), shaded surface display(SSD) a nd Raysum. Methods 64 patients with colorectal carcinoma s underwent volu me scanning using spiral CT. MPR, CTVC, SSD and Raysum images were obtained by u sing 4 different softwares in workstation. All cases were proved by surgical or CC bioptic histology. The results were compared and analyzed according to the circumferential extension, length and pathologic patterns of colorectal carcinoma with MPR, CTVC, SSD and Raysum. Results The correct ion rate of dete rmination the circumferential extension of colorectal carcinoma with MPR, CTVC, SSD and Raysum were 1000%, 828%, 797% and 797%, respectively There wa s signi ficant statistical difference between MPR and CTVC; The accuracy of judging the leng th of carcinoma were 891%, 766%, 953% and 1000%, respectively. There wa s stat istical difference between CTVC and SSD; The accuracy of showing carcinoma patho logi c patterns were 813%, 922%, 719% and 719%, respectively. There was stati stica l difference between CTVC and SSD, too. MPR could correctly determine the circum ferential extension of colorectal carcinoma. In determination the length of carc inoma, Raysum was more accurate than SSD. CTVC could be more helpful in showing carcinoma pathologic patterns. Conclusion There were advantag es and disadvant ages in colorectal carcinoma examination with MPR, CTVC, SSD and Raysum, and the combination could display colorectal carcinoma more completely and comprehensiv ely.

Objective To analyze the time-density curve of the small HCCs in the arterial phase and to find out its unique features.Methods All lesions were imaged with single-level serial SCT.The attenuations of the lesion,hepatic artery and hepatic parenchyma were measured.The time-density curve was built with these CT values and their corresponding times.Results The time-density curves of the lesion and liver parenchyma were divided into three kinds:the first kind had two intersects(73%).The first one was seen at the time when the curve of the lesion went up over the one of the parenchyma and the second was seen at the point the curve came down below the parenchyma's.There was no second intersecting point in the second type(19.2%) and the curve of the lesion was below that of the parenchyma in the third (7.7%). Conclusion The initial time of the enhancement of small SHCC is (21.6?6) s.The optimal time of the enhancement of SHCC is (36?8) s.

Objective　To optimize the oral contrast media in three-dimensional display of gastric lesions. Methods　41 cases were randomly divided into 3 groups according to different oral contrast media administered: No. 1 air contrast group (n=17), No. 2 fat emulsion group (n=7) and No. 3 positive contrast group (n=25). The 3D CT images were reconstructed using MPR, SSD, RaySum display and virtual endoscopic techniques, and compared with gastric endoscopy and/or conventional barium study.Results　The detectability of gastric lesions using fat emulsion and air contrast was 42.8%(3/7) and 80.0%(20/25), respectively, both were significantly lower than that using positive contrast (100%, 30/30) (χ2=19.22,P＜0.01;χ2=6.60, P＜0.05). The capability of showing the details of stomach lesions was significantly affected by the oral contrast media administered（χ2=17.04，P＜0.01）. Conclusion　It is very important to choose the appropriate oral contrast media for 3D display of gastric lesions in spiral CT, the positive contrast agent is the optimal choice.

Objective　To evaluate the value of gradient-echo chemical shift imaging in detection of lipid-containing abdominal lesions. Methods　35 patients with abdominal lesions were divided into 2 groups according to whether or not they contained lipid. Breath-hold in-phase(IP) and opposed-phase(OP) acquisitions were performed. The demonstration of these lesions on IP and OP was compared. The signal intensity of these lesions on both images was measured. The percentage of signal intensity variation on IP and OP was calculated and statistically analyzed with non-parametric method between the 2 groups. Results　For lesions containing lipid, the signal intensity dropped significantly from IP to OP, with median value of signal intensity variation attaining 37.1%. On the other hand, for lesions not containing lipid, the signal intensity did not change obviously between IP and OP, whose median value of signal intensity variation was 3.3%. The difference between the 2 groups was statistically significant (u=4.56，P<0.01). Conclusion　Gradient-echo chemical shift imaging is an easy and practical way, helpful to detection of lipid component within abdominal lesions.

Objective To evaluate the clinical effect in patients with primary liver cancer (PLC) well filled with Lipiodol after transcatheter arterial chemoembolization (TACE). Methods 144 patients with PLC well filled with lipiodol after TACE were analysed retrospectively, and the survival rates were calculated by Kaplan Meier method. Results The overall cumulative survival rates for 1,2,3,4 and 5 year were 85.0%, 63.7%, 51.7%, 33.9% and 16.9% respectively. Significant differences were found for 1,2,3 and 4 year survival rates and that of 400 patients with PLC treated by TACE reported previously by our department ( P

Objective To investigate the safety and efficacy of placement of self expandable metallic stent within right atrium and inferior vena cava (ICV) in patients with malignant ICV obstruction involving right atrium. Methods There were 5 male patients with advanced hepatocellular carcinoma, aged from 42 to 65 years (mean 56 3 years). The malignancies invaded right atrium and ICV simultaneously, and caused obstruction of ICV. These patients presented symptoms and signs of obstruction of ICV such as hepatomegaly, ascites, edema of lower extremities. “Z” type stainless steel stents (7 5～10.0 cm in length and 2 5 cm in diameter) were selected for these patients. Part (1.0～3.0 cm in length ) of stent was placed in right atrium and the rest was in ICV. Results All of stents were placed successfully and obstructed ICV reopened. The symptoms of obstruction of ICV relieved or disappeared. There were no recurrence of symptoms of obstruction of ICV and any cardiac complication related to placement of stents in follow up period (67～188 days). Conclusion Placement of self expandable metallic stent within right atrium and ICV in treatment of patients with malignant ICV obstruction involving right atrium is one of the safe and effective methods.

Objective To investigate the MR features of uterine leiomyomas and evaluate its diagnostic value. Methods Twenty six patients with probable uterine leiomyomas underwent preoperative ultrasound, T 1 weighted spin echo and T 2 weighted fast spin echo MR examinations. Among them, 11 cases were performed with dynamic contrast enhancement. Comparative analysis between MRI findings and pathologic results was done. Results MRI diagnosis in all cases was consistent with the results given by surgery and pathology, except 2 being pathologically proven as endometrial polyp or inflammatory pseudoplasma. The diagnostic accuracy of MRI was 92%, while the accuracy of ultrasound was 85%. The difference between the number of lesions detected by two modalities had statistical significance (89% for MRI vs 69% for ultrasound, ? 2=17.86, P

Objective To analyze the variable appearances of hepatic angiomyolipomas on CT and MRI, and to improve the diagnostic accuracy with CT and MRI. Methods All 13 cases were proved by surgical pathology. Helical CT scanning of pre- and post-contrast arterial phase, portal venous phase were performed in 12 cases, delayed phase scanning was performed in 5 of 12 cases. Magnetic resonance imaging with SE T 1WI, FSE T 2WI, and FMPSPGR axial dynamic multi-phase contrast scanning were performed in 7 cases. Results On pre-contrast CT scans, 11 of 12 lesions appeared as hypodensity, the other one appeared as slight hyperdensity. On the arterial phase scans, all lesions were markedly enhanced, the central vascular structure could be seen in 8 lesions. On the portal venous phase, 8 lesions remained enhanced and the central vascular structure could also be seen in 6 lesions. 5 of 7 lesions showed inhomogeneous hypointensity on SE T 1WI, and all of 7 lesions showed hyperintensity (from slight hyperintensity to strong hyperintensity) on FSE T 2WI. 6 lesions showed enhancement on the MR arterial phase scans, the other one showed no marked enhancement because the most parts of the lesion were fat. 4 lesions showed prolonged enhancement on the portal venous phase, and the other 3 lesions showed hypointensity. The central vascular structure could also be seen in 4 of 7 lesions on MR contrast dynamic scanning. Conclusion Both CT and MR could demonstrate the characterization of hepatic angiomyolipomas, especially the central vascular structure in the lesions strongly hint the diagnosis of angiomyolipomas. MR SE sequence with fat suppression is more sensitive than CT in the demonstration of the fat. CT and MR dynamic multi-phase contrast scanning can fully reflect the characterization of hepatic angiomyolipomas and can be helpful to improve the diagnostic accuracy.

Objective To evaluate the mult iphase hepatic CT scan for detecting the hypervascular hepatocellular carcinoma (HCC) by using multidetector row helical CT (MDCT). Methods Multiphase hepatic CT scan of the liver in 40 patients with HCC was carried out with Marconi 8000 multidetector row helical CT scanner .The early arterial phase scan, late arterial phase scan, and portal venous phase scan were started at 20 s, 34 s, and 80 s after the injection of contrast medium, respectively. The numbers of the detected lesions were calculated in each phase. The density values of the liver and tumor were measured for HCC ≥1 cm, and the density difference values of the liver and tumor in each phase were statistically calculated and analyzed. Results The study showed that a total of 61 lesions was found in 40 cases, and the lesions ≥ 1 cm were 47. The density difference values between hepatic parenchyma and HCC in the 47 lesions were significantly different at the early arterial phase, the late arterial phase, and the portal venous phase ( P