Objective To evaluate the tumor targeting characteristic by observing signal varying of human gastric cancer transplanted nude mice (SGC-7901) using Folate-Receptor MR contrast agent. Methods As a Folate-Receptor MR contrast agent, Gd-DTPA-Folate was obtained by conjugation of DTPA-Folate and GdCl3 under specific conditions. Nude mice of subcutaneously transplanted human gastric cancer (SGC-7901) were used as animal models, 12 mice were divided into experimental group(n=6) and control group(n=6) randomly. Both were injected with Gd-DTPA-Folate and Gd-DTPA (contained same gadolinium) via abdominal cavity respectively. Tumor signal varying was observed by T1WI after injection of contrast agent immediately,1,2,3,4,6,12 and 24 h, and tumor signal changing of experimental group was compared with that of control group. CNR (contrast noise ratio) was regarded as evaluating mark. Results Tumor signal intensity of experimental group was increased evidently between 1-2 hours after injecting Gd-DTPA-Folate. Comparison with pre-injection, there was a significant difference(evaluating mark is CNR: q1=5.80, q2=4.64; P0.05). Conclusion Gd-DTPA-Folate shows definite characteristic of tumor targeting effect to nude mice of subcutaneously transplanted human gastric cancer (SGC-7901).

Background and purpose:A pre-surgery diagnosis of cervical invasion in endometrial cancer was usually determined by dilatations and curettage(D&C),so it could help in optimizing surgery,but the reliability of D&C still was controversial.This study was to compare MRI with D&C to estimate their accuracy for the diagnosis of cervical invasion in endometrial carcinoma respectively.Methods:34 endometrial cancer patients had been proved to have cervical invasion in endometrial cancer through examinations of either fractional dilatations and curettages(D&C),magnetic resonance imaging(MRI)before surgery or postoperative histopathologic examination.The results of D&C and MRI were compared with postoperative histopathologic examination,and the sensitivity,specificity were estimated for accuracy of cervical involvement in endometrial cancer.Results:21 of 34 patients were identified as having cervical invasion in endometrial cancer by histopathology after operation.D&C test matches 26.5% of them and MRI test matches 80%.The sensitivity was 35% vs.76.5% and the specificity 7.7% vs.100% for D&C and MRI methods respectively.All of them had significant statistical differences.Conclusions:MRI test is much better than D&C method for preoperative diagnosis of cervical invasion in endometrial carcinoma.

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 describe the characteristic MR appearances in hepatocellular carcinoma after radiofrequency ablation (RFA) during follow-up studies. Methods MR images of 110 patients with hepatocellular carcinoma after RFA ,which were categorized into 3 MR examination intervals ( ≤48 h, 1-6 m, ＞6 m), were analyzed retrospectively. The sequential changes of MR images were assessed and compared using Chi-square test. Results All RFA areas of 110 patients typically exhibited hyperintensity on GRE-T1 WI and hypointensity on TSE-T2 WI with fat suppression within 48 h after ablation. Subsequently,the signal intensities of the RFA areas decreased on GRE-T1 WI which showed significant differences after 6 months( P ＜0. 015 ). On GRE-T1 WI , RFA lesions were hyperintense in 72, iso-or hypo-intense in 4 at 1-6 months and hyperintense in 60, iso-or hypo-intense in 17 after 6 months. On TSE-T2 WI, 65 RFA lesions were hypointense, 11 isointense at 1-6 months and 47 were hypointense, 30 isointense after 6 months. The increased intensity on TSE-T2 WI showed significant differences after 6 months( P ＜ 0. 015 ).On contrast-enhanced MR images, RFA lesions showed peripheral rim of enhancement within 48 h and exhibited a tendency to show no enhancement ( n = 37 at 16 months and n = 63 after 6 months ) with significant differences between MR examination intervals( P ＜ 0. 015 ). In 6 patients with residual tumor or local tumor progression, nodular lesions were found at the periphery of the RFA. These nodular lesions showed moderate to marked enhancement as well as hypointense signal on GRE-T1WI, and moderate hyperintense signal on TSE-T2WI. Conclusion MR imaging could depict the characteristics of coagulative necrosis of tumor, residual tumor or local tumor progression in patients with hepatocellular carcinoma after RFA therapy.

Gadolinium DTPA ; Humans ; Magnetic Resonance Imaging ; Non-alcoholic Fatty Liver Disease

Objective To evaluate the value of multi-slice CT(MSCT)classification in the assessment of the hilar cholangiocarcinoma resectahility.Methods Thirty patients with surgically and histopathologically proved hilar cholangiocarcinomas who underwent preoperative MSCT and were diagnosed correctly were included in present study.Transverse images and reconstructed MPR images were reviewed for Bismuth-Corlette classification and morphological classification of hilar cholangiocarcinoma.Thcn MSCT classification was compared with findings of surgery and histopathology.Curative resectabilty of different types according to Bismuth-Corlette classification and morphological classification were analyzed with chi-square test.Results In 30 cases,the numbers of Type Ⅰ,Ⅱ,Ⅲa,Ⅲb and Ⅳ according to BismuthCorlette classification were 1,3,4,5 and 17.Seventeen patients underwent curative resections,among which 1,2,1,4 and 9 belonged to Type Ⅰ,Ⅱ,Ⅲa,Ⅲb and Ⅳ respectively.However,there was no significant difference in curative resectability among different types of Bismuth-Corlette classification(X2=0.9875.P＞0.05).In present study,the accuracy of MSCT in Bismuth-Corlette classification reached 86.7%(26/30).The numbers of periducatal infiltrating,mass forming and intraductal growing type were 13,13 and 4,while 6,8 and 3 cases of each type underwent curative resections.There was no significant difference in curative resectability among different types of morphological classification(X2=1.2583,P＞0.05).The accuracy of MSCT in morphological classification was 100%(30/30)in this study group.Conclusion MSCT can make accurate diagnosis of Bismuth-Corlette classification and morphological classification.which is helpful in preoperative respectability assessment of hilar cholangiocarcinoma.

Objectives To analyse the radiological features of dynamic MRI and diffusion weighted imaging for atypical small hepatic hemangiomas (≤2 cm).Methods The MR images of 14 patients with 14 pathologically-confirmed small atypical hepatic hemangiomas were retrospectively analyzed.All these patients underwent MR imaging including plain T1 weighted imaging,T2 weighted imaging,dynamic contrast enhanced scanning,and diffusion weighted imaging.The signal-to-noise ratios of hemangiomas,the portal vein and the aorta,lesion-to-liver contrast-to-noise ratios,ADCs of hemangiomas and the liver,lesion-to-liver signal ratios in DWI were assessed to generalize the MRI features and the key points in differential diagnosis of this type of hepatic hemangioma.Results In dynamic contrast enhanced scanning,the atypical hemangiomas were barely enhanced and they were hypointense most of the time.The lesions might show a faint enhancement in the delayed phase.There were significant differences in the changes in signal-to-noise ratio between hemangiomas and aorta as well as portal vein in all the three phases (P＜0.05).In DWI,the signal intensities and ADCs of the hemangiomas were higher than the liver parenchyma (P＜0.01).Conclusions MRI dynamic contrast enhanced scanning,diffusion weighted imaging and evaluation of the ADCs were important in the diagnosis and differential diagnosis of small atypical hepatic hemangiomas.

Objective To investigate the MRI features of hepatic IgG4?related inflammatory pseudotumor (IPT). Methods Nine patients with 11 histopathologically proven IgG4?related hepatic IPTs were retrospectively analyzed. The clinical, morphological and MRI signal features on T1WI, T2WI, dynamic?enhanced, and diffusion?weighted imaging were assessed in detail and correlated with pathological findings. The paired t test was used to compare the ADC values of the tumors and the hepatic tissue. Results Hepatic IgG4?related IPT displayed certain MRI features. The dominant lesions were subcapsularly distributed (n=7) with a clear boundary (n=8), which typically showed hypointensity on T1WI (n=11), mild hyperintensity on T2WI (n=8), progressive (n=5) or persistent (n=4) enhancement pattern. Accompanied signs included delayed capsule?like enhancement (n=6) and central nonenhanced areas (n=7). Two lesions showed atypical wash?out pattern with iso or hypointensity on portal and delayed phases. In diffusion weighted imaging, all lesions were hyperintense, and the mean ADC value of the lesions [(1.42 ± 0.36) × 10?3mm2/s] was mildly lower than that of surrounding liver [(1.55±0.31)×10?3mm2/s], although no statistical differences were found(t=0.78, P=0.46). Conclusions Hepatic IgG4?related IPTs display various MRI manifestations. The lesions normally show progressive enhancement pattern with diffuse homogeneous or heterogeneous hyperintensity, accompanied by delayed capsule?like enhancement and central nonenhanced areas.

Objective To discuss the diagnostic value of CT and MRI for primary anorectal malignant melanoma(AMM).Methods 5 patients(2 males and 3 females)with AMM confirmed pathologically were analyzed retrospectively,which were examined by CT(n=4)and 1.5T MRI(n=1).Results AMM presented as bulky intraluminal fungating masses without intestinal obstruction(n=4)and irregular rectal wall thickening(n=1).2 cases had perirectal fat infiltration and extended to the presacral space in one case,4 cases had perirectal enlarged lymph nodes and larger than 3 cm in diameter in one case.Nonenhanced CT showed a hypodense lesion and contrast-enhanced CT showed slight enhancement(n=1)and mild enhancement(n=3).The tumor scanned by MRI depicted high intensity on T1WI and low intensity on T2WI,so did the enlarged lymph nodes and bone metastasis.Fat-saturation T1WI significantly improved the extention of tumor and detection of metastasis.Conclusion Bulky intraluminal fungating masses without intestinal obstruction,perirectal fat infiltration and enlarged lymph nodes may be helpful to diagnose AMM.MRI is especially useful in differentiating melanotic AMM from other rectal tumors.

Objective To evaluate the relationship between the T1 relaxation times using gadoxetic acid-enhanced MRI with the organic anion transporter (OATP) and multi-drug resistance protein (MRP) values on colorectal liver metastasis and around normal liver parenchyma.Methods The perspective study included in fifteen patients with liver metastasis from colorectal cancer,who were confirmed colorectal cancer by colonoscopy,liver metastasis by CT scanning and would be underwent liver metastasis surgery.The lesion on the 15 patients was all single.The patients were performed plain scanning,diffusion weighted imaging and dynamic enhancement MRI examination using gadoxetic acid.Besides,for T1 mapping,a dual flip angle three-dimensional gradient echo sequence was performed before and at 20 minutes after gadoxetic acid administration.The reduction rate of T1 relaxation time (ΔT) (before and after gadoxetic-acid administration) of colorectal liver metastasis and around normal liver parenchyma was calculated.The specimens of hepatic metastases and around normal liver parenchyma were obtained during the colorectal liver metastasis operation.After that,they were analyzed by Western-blot and the values on OATP1,OATP8 and MRP2,MRP3 were recorded.The values on OATP1,OATP8 and MRP2,MRP3 and ΔT on hepatic metastases and around normal liver parenchyma were compared with t analysis.The correlation between the sum of the values (hepatic metastases adding around normal liver parenchyma) on OATPI,OATPS,MRP2,MRP3 with T1 relaxation times were calculated by Spearman.Results The scanning images on colorectal liver metastasis using gadoxetic acid MRI examination were as follows:relatively low signal intensity on T1WI; relatively higher signal intensity on T2WI; showing surrounding moderate enhancement on arterial phase and low signal intensity on portal venous phase,delay phase and hepatobililary phase.The values on OATP1,OATP8,MRP2,MRP3 and AT on the hepatic metastases were(0.21±0.09),(0.34±0.21),(0.41±0.22),(0.26±0.14)ng/ml and (33±9)％,respectively.The values on OATP1,OATP8,MRP2,MRP3 and ΔT around normal liver parenchyma were (0.46±0.24),(0.67±0.35),(0.22±0.13),(0.13±0.06) ng/ml and(68±9)％ (t values were 36.37,58.89,24.56,22.52 and 57.16;P＜0.05).The values on patients on OATP1,OATP8,MRP2 and MRP3 [(0.67±0.31),(1.00±0.37),(0.63±0.23),(0.40±0.13)ng/ml,respectively] showed relationship with the values on patients on ΔT(51±9)％ (r values were 0.491,0.432,-0.414 and-0.371;P values were 0.006,0.017,0.023 and 0.040).Conclusion The sum of the values (the hepatic metastases adding around normal liver parenchyma) on OATP1,OATP8,MRP2 and MRP3 showed correlation with the sum of values on the ΔT using gadoxetie acid-enhanced MRI examination,which explained relationship with the quantity of gadoxetic acid absorbed by hepatocyte and the T1 relaxation time on molecular level.