Medical imaging is evolving from the traditional morphologic examination to a pattern that combines morphologic and functional examinations that can reflect physiochemical changes at cellular and molecular levels. Functional imaging techniques, including CT perfusion imaging, MR diffusion weighted imaging, MR perfusion imaging and MR spectroscopy, have been drawing increasingly more attention in pathological study of the livers, pancreas, kidneys, prostates and lymph nodes, and the prospect is promising. CT & MR functional imaging combined with morphologic examination is helpful for the diagnosis and differential diagnosis of pathological lesions.

Objective To study the changes of imaging features of rats with implanted liver cancer before and after electrochemotherapy (EChT).Methods Immediate cancerous ascites injection method was used to form rats liver cancer model. The imaging features of rats with implanted liver cancer, including tumor size, density, border, enhancement and singal were observed with CT and MRI respectively. Results The characteristic magings showed all these rats bearing single, round tumor in liver seven days later. Low density lesions were seen in pre contrast scans and tumor border intensification were seen on contrast scans. Low signal lesions were found in MRI T 1WI and high signal lesions were revealed on MRI T 2WI. Seven days after EchT, low density lesions were seen in pre contrast scan and non enhanced appearences were seen in contrast scan by CT. High signal and mixed signal lesion were seen in MRI T 1WI and relative low signal lesion were seen in MRI T 2WI.Conclusions Imaging features analysis is useful to assess the therapeutic effect on rats with implanted liver cancer before and after EChT.

Objective To compare the effects of electrochemotherapy (EChT) on implanted liver tumor cells apoptosis of rats.Methods Immediate cancerous ascitis injection method was used for the formation of rats liver tumor model and then followed by rats liver tumor treatment with EChT. Tumor size, necrosis and apoptosis indexes were observed after one week by imaging or pathologic method. The results were compared with those of control group. Results Before EChT, rats liver tumor volume appeared as (100?6)mm 3 and turned to be (125?10)mm 3 one week after EChT, which were significantly smaller than those of the control group [(190?11)mm 3], P

Objective To compare the therapeutic effects of electrochemotherapy (EChT) and radiofrequence ablation (RFA) on rats with implanted liver cancer.Methods Immediate cancerous ascites injection method was utilized for creation of rats liver cancer model and followed by treatment with EchT and RFA respectively. Tumor size, necrosis and apoptosis were observed one week later by imaging and pathology. The results were compared with those of control group. The survival times were observed also. Results Before treatment, all rats average liver tumor volume was (100?6)mm 3. One week after treatment, average tumor volumes in EChT group [(125?10)mm 3] and RFA group [(143?12)mm 3] were significantly smaller than those of control group [(190?11)mm 3], but tumor volume showed significant statistical difference between EChT group and RFA group. Necrosis, apoptosis and survival times in EChT group and RFA group were significantly higher than those of control group.Conclusions EChT or RFA could promote tumor necrosis, induce apoptosis, inhibit tumor growth and prolong the survival time of rats with implanted liver cancer.

Objective To evaluate the features of solid-pseudopapiHary tumors of pancreas (SPTP),and to compare with the clinical and pathological findings in order to improve the diagnostic accura-cy.Methods The CT appearances were analyzed retrospectively in 5 patients with pathologically proven SPTP.There were 4 women and 1 man,with the mean age of(16.20±7.49)years.Plain CT and contrasted CT were performed in all 5 cases.Results The tumors of 4 caseswerelocatedinthe head and neck of pan-creats and 1 case was in the body and tail of pancreas.Clear tumor margins were seen in all cases.The mean diameter of these tumors was 5.2 cm(3.0-9.0 cm).Two cases were predominantly composed of cystic por-tions,2 cases were mainly composed of solid portions,and 1 case was composed of similar proportions of solid and cystic portions.Inhomogeneous enhancement Was rewealed in contrasted CT scan,but Was lower in both phase than normal pancreas.Tumor border discontinuous ring-shape calcification was seen in 1 case,dilata-tion of the main pancreatic duct Was demonstrated in 1 case and no metastasis were seen.Conclusions Certain CT features may suggest the diagnosis of SPTP.CT combined with the clinical feature is helpful to the diagnosis.

ObjectiveTo establish nude mouse tumor models bearing human pancreatic adenocarcinoma SW1990 cells in multiple sites at different time-points and investigate the feasibiilty of multiple tumor-bearing in these models; then the findings and detection rate of 3.0T magnetic resonance image (MRI) in subcutaneous transplanted tumors was analyzed. Methods A total of 6 BALB/C nude mice were randomized into 3 groups (2 mice per group ).At the 1st,8th,15th day,the mice were injected subcutaneously with the suspension of SW1990 cells at left axilla and right axilla and right groin in sequence.Three weeks later,all the bearing-tumor mice were performed with MRI non-contrast enhanced scanning plus Gd-DTPA enhanced scan and the subcutaneous masses were subjected to pathological analysis.ResultsAll the 6 nude mice were alive during the study and obvious mass was observed in every injected site.The tumor size was positively associated with the grwing time.There were 9 tumors which could be de.ted by noncontrast enhanced MRI scanning and one more tumor was detected by contrast enhanced scanning.2 tumors were not detected,the 2 tumors were located at subcutaneous of right groin,with the shortest growing time,and the major axis of the 2 un-detected tumors was less than 5mm.Despite the MRI findings of the transplanted masses similar to that of human pancreatic adenocarcinoma with bleeding,necrosis,they presented the characteristics of a clear rim,with pseudocapeule sign.All the 12 masses were similar with human pancreatic adenocarcinoma under light microscope.ConclusionsIt is feasible to transplant human pancreatic adenocarcinoma cell at three different subcutaneous sites (injected at three different points of time) in the nude mouse,with a minimal survival time of three weeks.However,routine 3.0T MRI cannot detect the early tumors (growing time within 1 week,major axis ＜5 mm).

Objective To improve the diagnosis of germinomas in basal ganglia area by analysing the imaging manifestations.Methods Clinic,pathologic and medical imaging data of 8 cases of germinomas in basal ganglia area confirmed pathologically were analyzed retrospectively.Results 8 cases were all men,the age ranged from 5~13 years old with mean age of 10.5 years.All cases had change of muscle strength on one side of extremity,and one case accompanied by intracranial hypertension,this case was showed the effect of space occupying of the tumor obviously and hydrocephalus on CT and MRI.The findings of CT and MRI showed cystic degeneration in 4 cases,slight edema around the tumor in 2 cases,cortex atrophy of the same side of tumor in 2 cases and calcification in the tumor in 2 cases.All cases were enhanced greatly.The pathologic specimen with rich supply of blood was gray-red,and cystic degeneration was seen in 4 cases.Conclusion CT and MRI features of germinomas in basal ganglia area are quite characteristic,the improvement of diagnosis can be achieved in combination with clinical manifestation.

Objective To investigate the CT and MRI features of the autoimmune pancreatitis (ALP).Methods CT and MRI data of fourteen patients with AIP who were confirmed by histology and/or steroid therapy were retrospectively analyzed.Ten patients underwent CT examination, and seven patients underwent MRI, while three patients underwent both CT and MRI examinations.Results It was showed that diffuse (n =11 ) or local ( n = 3 ) enlargement of pancreas.CT features showed that the hypoattenuation pancreatic lesions on unenhanced CT (n = 10);segmental pancreatic duct could be seen in five patients;stenosis of common bile duct in the head of pancreas was observed in 5 patients;the capsule-like structure around lesions was seen in seven patients.Delayed homogeneous enhancement was showed on enhanced CT.MRI features included homogeneous ( n = 3) and heterogeneous ( n = 4) hyperintense on T1 WI with fat-suppression images and homogeneous ( n = 3 )and heterogeneous (n =4) hyperintense on T2WI with fat-suppression images.Pancreatic duct could be seen in four patients.MRCP showed pancreatic duct stenosis in the head of pancreas ( n = 1 ) and segmental pancreatic duct (n = 2).Stenosis of common bile duct in the head of pancreas was showed in 5 cases.The capsule-like structure around lesions was showed in seven patients.No pancreatic calcification was revealed, and no significant pancreatic duct dilation was detected ( ＞3 mm) in all 14 patients.Conclusions The CT and MRI manifestations of AIP had characteristic features such as sausage-like changes of the pancreas, capsule-like structure around the lesions, diffuse or local pancreatic duct stricture, and stenosis of common bile duct in the bead of pancreas.

Objective To explore the value of multislice spiral computed tomography ( MSCT ) in predicting the resectability of pancreatic cancer ( PC) .Methods The MSCT images of 102 PC patients ( 62 men, mean age, 61 ±9 years;40 women, mean age, 60 ±9 years) confirmed by postoperative pathology were analyzed retrospectively .The images were analyzed and evaluated by 2 senior radiologists who were double blinded.The relationship between tumor and vessels was investigated based on consensus statement on the radiological diagnosis of PC of the Society of Abdominal Radiology and the American Pancreatic Association in 2014 .The diagnostic criterion on the resectability of PC was based on the 2015 NCCN Clinical Practice Guidelines on PC . Image analysis included the lesion location , size and density , the characteristics of pancreatic and bile ducts , relationship of tumor and adjacent vessels , the extrapancreatic findings as well as T staging and resectability.Results The locations of PC were found in the pancreatic head (n=71,69.6%), body (n=23, 22.5%) and tail (n=8, 7.8%).The long-and short-axis diameter were (28.9 ±8.8)mm and (23.8 ±8.0)mm in head, and respectively, (31.2 ±11.0)mm and (23.8 ±6.3)mm in body and tail, respectively.The imaging findings included hypo-(n=98, 96.1%) and iso-density masses (n=4, 3.9%) on pancreatic phase, intra-and extrahepatic bile duct dilation (n=63, 61.8%), main pancreatic duct cut-off with dilation (n=46, 45.1%), the pseudocyst (n=4), acute pancreatitis (n=1) and chronic pancreatitis (n=2).T staging evaluation by MSCT observed T1 (n=3), T2 (n=7), T3 (n=78) and T4 (n=14), respectively.MSCT assessment for T staging was correct in 98 (96.1%), but wrong in 4 (3.9%), which was quite consistent with pathological T staging (K=0.88, P<0.05).MSCT assessment for the resectability was correct in 98 (96.1%), but wrong in 4 (3.9%).Sensitivity, specificity, positive and negative predictive values, and area under curve of MSCT in the assessment of the resectability were 96.8%, 87.5%, 98.9%, 70.0%and 92.2%, respectively.Conclusions MSCT could improve the diagnostic accuracy for T Staging and resectability of PC .

Objective To observe computed tomography features of neuroendocrine tumor of the pancreas.Methods Computed tomography scans for 28 patients with pathologically proven neuroendocrine tumor of the pancreas were retrospectively analyzed.The data of tumor locations,diameters of the tumor and internal composition,pattern of enhancement,changes of biliary and pancreatic duct,and lymphatic metastasis,remote metastasis were recorded.Results A total of 32 lesions were detected,24 lesions were single lesions,while 4 lesions were multiple lesions (2 lesions within pancreas).The shapes of these lesions were nodule-like or mass-like.Eighteen lesions were located in pancreatic tail,10 in pancreatic head,2 in pancreatic body,and 2 between pancreatic tail and body.Among the lesions located in pancreatic head,pancreatic duct dilation were detected in 5 cases,bile duct dilation in 1 case,both biliary and pancreatic duct dilation in 2 cases,and no dilation in the remaining 2 cases.The diameters of the tumor ranged from 1.0 to 20.0cm (mean5.1 cm),and the size was ＜2 cmin 1 case,2 ～5 cm in 23 cases; ＞5 cm in 8 cases.After enhancement,the lesions were enhanced to different degrees,and the peak value occurred in the pancreatic phase.Twenty-three lesions invaded adjacent vessels or organs,and lymphatic metastasis was observed in 5 cases,remote metastasis were recorded in 6 cases.Conclusions Neuroendocrine tumor of the pancreas has certain features on computed tomography.It is highly likely to make the pre-operative diagnosis when clinical data is also taken into consideration.