Objective: To evaluate the diagnostic value of the special sequences and methods of MRI in liver cirrhosis and portal hypertension. Methods:100 cases of liver cirrhosis were examined by 3DT1W/FFE and SENSE-BABLANCE sequences and compared with normal livers. Results: ① 3DT1W/FFE imaging has clear advantage over conventional scan in detecting cirrhotic nodules. ② The peak of signal intensity ASD (average standard deviation) in normal livers and the minimum of signal intensity ASD in liver cirrhosis cases were found . If signal intensity standard deviation in liver was over 30, liver cirrhosis should be considered. ③ The degree of hypertension and the size of portal vein and its branches were evaluated by SENSE-BABLANCE sequences. Conclusion: MRI special sequences and methods play a significant role in the early diagnosis of liver cirrhosis and portal hypertension.

Objective To evaluate the interstital MR lymphography using positive lymphotropic contrast agent for differentiation of metastatic lymph nodes from inflammatory lymph nodes hyperplasm.Methods Eighteen New Zealand white rabbits weighted at 2.0-2.5 kg were used.Inflammatory hyperplastic popliteal lymph node model was established in 9 rabbits by injection of complete freund adjuvant into the interdigitial skin of the dorsal aspect of one hind leg,and tumor-bearing popliteal lymph node model was established in another 9 rabbits by injection of VX~2 tumor cell suspension.The popliteal lymph nodes of another hind leg of all 18 rabbits were assigned to the normal contral group.In each group,every rabbit underwent MR lymphography examination before and after the inoculation.Volumes of 0.2 ml of Gd[DTPA-bis(2-aminoethoxy)ethane]polymeric contrast agent(Gd-poly-DTPA-EOEA)injection were injected subcutaneously into the dorsal feet of both hind legs of two groups of rabbits.T_1-weighted 3D gradient-echo images were obtained,and source images were used to reconstruct images of MIP before and after the administration of agent.The maximum short-axis diameter(MSAD)of each popliteal lymph node was measured on the enhanced 3D MIP images,and the signal-to-noise ratio(SNR)measurement was performed in the largest popliteal node of each rabbit at each time point in delayed scan.Independentsamples t test was used to compare the sizes of popliteal nodes in MSADs between inflammatorily hyperplastic and tumor-bearing nodes after the inoculation,and the values of SNRs of popliteal nodes at each time point between inflammatorily hyperplastic,tumor-bearing and normal popliteal lymph nodes.Imaging results of the popliteal nodes were analyzed and correlated with pathological findings.Results All of the rabbits were successfully inoculated except of the 2 rabbits in tumor-bearing nodal group.The size in MSAD of 13 inflammatorily hyperplastic and 11 tumor-bearing nodes was(1.32±0.14)and(1.33±0.12)cm,respectively.There was no significant statistical difference between the sizes of the two groups(t=0.186,P＞0.05).At the time of 5,15,30,60,90,120 minutes after the injection of the agent,the value of SNR of 9 inflammatorily hyperplastic and 9 contralateral normal nodes was 17.31±0.37 and 17.19±0.29,27.42±0.50 and 27.39±0.48,38.44±0.47 and 38.19±0.27,37.10±0.09 and 36.97±0.10,36.32±0.61 and 36.20±0.80,34.60±0.44 and 34.71±0.32,respectively.There was no significant statistical difference between the values of the two groups(t=0.78,0.14,1.43,1.00,0.36,-0.62,respectively,P＞0.05).The value of SNR of seven tumor-bearing and seven contralateral normal nodes was 6.00±0.22 and 17.21±0.28,7.87±0.16 and 27.17±0.23,8.14±0.24 and 38.16±0.19,8.09±0.28 and 36.94±0.30,7.59±0.20 and 35.96±0.72,7.50±0.14 and 34.81±0.27,respectively.There was significant statistical difference between the values of the two groups(t=-84.00,-182.72,-261.27,-186.48,-100.22,-239.00,respectively,P＜0.01).At each time point,inflammatorily hyperplastic nodes had significantly higher values of SNRs compared to tumor-bearing nodes(t=83.97,174.07,158.49,152.71,96.06,154.57,respectively,P＜0.01).A complete or part signal filling defect occurred in the tumor-bearing lymph node on the MR lymphographic images.Conclusions The internal anatomy and function of the lymph nodes were effectively visualized by interstitial MR lymphography with positive lymphotropic contrast agent,which provide a sensitively diagnostic way for the differentiation of benign lymph nodes from malignant ones.

Objective To evaluate in vivo tracking of swine mesenchymal stem cells (MSCs) la-beled with super paramagnetic iron oxide (SPIO) in intraportal transplantation by a clinical 1.5T MR.Methods MSCs were isolated from swine and cultured as well as expanded, which were then incuba-ted with SPIO (Feridex I. V.). Prussian blue staining was performed for showing intracelluar irons.To establish a swine model of acute liver necrosis, 0.5 g/kg of D-galactosamine was administrated to 10 pigs. MSCs(labeled cells in six, unlabeled cells in four)were injected into liver via portal veins. MR imaging was performed with a clinical 1.5T MR immediately before and at 6 h, 3 d, 7 d, 14 d after transplantation, respectively. Results Prussian blue staining of SPIO labeled MSCs could be effec-tively labeled and the labeling efficiency was almost 100%. Signal intensity loss in liver by SPIO labe-ling on FFE sequence persisted until 14 days after transplantation. Histological analysis by Prussian blue staining showed homing of labeled MSCs in liver after 14 days, primarily distributing in hepatic sinusoids and liver parenchyma. Conclusion MSCs can be labeled with SPIO in vitro successfully.MRI can monitor magnetically labeled MSCs transplanted into liver.

Objective: To discuss the application of BALANCE-FFE sequence in abdominal MRCP.Methods:100 patients of abdominal diseases were examined by BALANCE technique. Results: The signal of BALANCE-FFE sequence was high in abdominal MRCP examination, and BALANCE image of the coronal scan was excellent. Conclusion:The biliary tract had obviously high signal intensity acquired by BALANCE sequence. The gallstone and the stenosis could be seen. The tissue out of the bile duct, the head of pancrease and the lymph could also be seen. The BALANCE sequence could be used as a supplement of conventional MRCP.

Objective To discuss the clinical presentations and imaging features of a novel avianorigin influenza (H7N9).Methods Anteroposterior chest radiographs and serial thin-section CT images in 5 patients with H7N9 were reviewed retrospectively by two radiologists,the predominant inaging patterns of lung abnormalities and clinical data were recorded and analyzed.Results The large consolidation of the right lung with air bronchograms was the most common radiographic appearance in all patients with H7N9 at admission,and the abnormalities were more severe in the bilateral lower lobes.Both lungs developed large,scattered consolidations and ground-glass opacities with the progression of disease.The lesions in the left lung were more rapidly absorbed than those in the right lung.Conclusion Influenza H7N9 has certain chest imaging characteristics in the onset,progression and recovery of disease.

Objective To explore the feasibility of echo planar imaging with short time inversion recovery(STIR-EPI)diffusion weighted imaging with background signal(DWIBS)suppression in breast cancer.Methods The diffusion weighted imaging(DWI)with background suppression(b=800 mm2/s)was performed in 26 patients with breast cancer.Apparent diffusion coefficient(ADC)of all lesions,vere measured and compared.3D maximum intensity projection(3D-MIP)and reverse black and white technique were used to show the lesions.DWI and DWIBS were performed and compared for the detection of breast cancer. Randomized blocks analysis of variance was used for the ADC values in different breast tissues.the ADC values in breast cancer and benign lesion were compared using t test.The paired chi square tes:was used for the detection rate of breast cancer in two different imaging methods.Results Most of the breast cancers were hyperintense on DWI(b:800 mm2/s).,rhe ADC value of caneer tissue was(0.93±0.25)×10-3mm2/s,tumor necrosis was(2.06±0.17)×10-3 mm2/s,normal breast tissue was (1.92±0.23)×10-3 mm2/s and metastatic lymph node was(1.10±0.14)× 10-3mm2/s and the differenees were statistically significant between two structures(P＜0.01).The signal of the tissue8 around the breast cancer was decreased on DWIBS with 3 D-MIP and reverse black and white technique and similar to positron emission tomography(PET).DWIBS sequence detected more breast cancers(92.3/)and metastatic lymph nodes(88.4/)than DWI sequence did(57.6/and 42.3/,respectively,X2:8.307,P＜0.05;X2=12.235,P＜0.05).The ADC values in breast cancer(1.09±0.17)×10-3mm2/s and benign lesion (2.15±0.53)×10-3 mm2/s had significant statistical differences(t=8.626,P＜0.05).conclusion Diffusion weighted MRI with background suppression can detect more lesions than DWI and can be potentially applied for the detection of the breast cancer eombining the ADC value.

Objective:To explore the safety and efficacy of Castor branched stent-graft exclusion in the treatment of aortic dissection and aneurysm involving left subclavian artery.Methods:The clinical and imaging data of 88 patients with aortic dissection or aneurysm involving left subclavian artery diagnosed by CTA or DSA in our hospital from December 2017 to December 2019 were collected retrospectively, including 67 aorta dissections, 7 thoracic aortic aneurysms and 14 aorta penetrating ulcer. All patients were treated with branched stent-graft under the guidance of DSA. The postoperative curative effect and complications were observed. The paired t test was used to compare the maximum aortic diameter of the lesion before and 6 months after the operation. Results:Eighty-eight patients were successfully treated with integrated stent, the success rate of operation was 100%, and the disease-related symptoms of all patients were basically or completely relieved. The mortality rate within 1 month after the operation was 2.7% (2/88). The two deaths were complicated with other serious diseases before the operation, and the cause of death was not related the operation. All patients were followed up except 4 patients who lost contact after discharge. During the follow-up, there were 1 case of retrograde type A dissection, 1 case of new aneurysm of aortic arch, 2 cases of in-stent stenosis of left subclavian artery branch, 3 cases of mild stroke, no persistent endoleak and no death or other serious complications. The mean maximum aortic diameter at 6 months after operation [(34±4)mm] was significantly lower than that before operation [(38±6 mm)] ( t=6.63, P<0.05). Conclusion:Castor branched stent-graft is simple, mini-invasive and effective in the treatment of aortic dissection and aneurysms involving the left subclavian artery.

Objective To investigate the feasibility of quantitative measurement of fat concentration by CT spectral imaging in a mice model of fatty liver.Methods Twenty-four mice with different degrees of fatty liver underwent CT spectral imaging.CT values of liver parenchyma under mixed X-ray energy and 65 keV,fat concentration based on various basic material pairs (fat/water,fat/io-dine,fat/calcium)and spectral curves were obtained.Liver specimens were obtained to measure the concentration of triglyceride , and HE staining was performed.Correlations between various CT indexes and triglyceride concentration were analyzed.Results Correlation between fat concentration (fat/water pair)and triglyceride (r =0.91 5 )was better than that between CT values on 65 keV and triglyceride (r=-0.858),as well as polychromatic CT values (r=-0.81 6).All the P values were<0.001.Correlations between fat concentrations based on fat/iodine or fat/calcium pairs and triglyceride were relatively low (r=-0.726,-0.660).CT indexes on 1.25 mm slice thickness performed better than those on 2.5 mm.With fatty liver degree increased,the shape of spectral curve changed gradually.Conclusion Liver fat concentration can be measured by CT spectral imaging noninvasively,accurately and quantitatively in a mice model of fatty liver.

Objective To assess the histological characteristics of cervical cancer using intravoxel incoherent motion magnetic resonance imaging ( IVIMMRI) and to investigate the performance of IVIMMRI in evaluation of the efficacy of concurrent chemoradiotherapy in the treatment of intermediate/advanced cervical cancer. Methods Pelvic MRI scans, containing T2WI, IVIM (14 b values, b=0?1 000 s/mm2), and contrast?enhanced T1 scans were performed in 23 patients pathologically diagnosed with intermediate/advanced cervical cancer ( stage ≥Ⅱb ) before chemoradiotherapy, after two and four weeks of treatment, and at the end of treatment. The IVIMMRI data were processed with the bi?exponential model to generate three parameters, containing pure diffusion coefficient ( D ) , pseudodiffusion coefficient ( D?) , and perfusion fraction ( f ) . Apparent diffusion coefficient ( ADC ) was obtained using the mono?exponential model. The IVIMMRI parameters were measured at each time point and their dynamics and correlation were analyzed. Results The ADC, D, and f values were significantly higher after complete treatment ( 0?96 × 10-3 vs. 1?77 × 10-3 mm2/s, P=0?000;0?76 × 10-3 vs. 1.34± 0?12 × 10-3 mm2/s, P=0?000;0?14% vs. 0?24%, P=0?012). The above three values significantly increased after two weeks of treatment (all P=0?000) and kept increasing until the end of the treatment. In contrast, the D? value was reduced from the second week to the end of the treatment. Conclusions IVIMMRI can monitor the dynamic functional changes and early tumor responses during chemoradiotherapy for cervical cancer, which holds promise for clinical application.

Objective To explore the value of gemstone spectral imaging (GSI)in quantitative evaluation of Lauren classification of gastric cancer.Methods Fifty-two patients with gastric cancer confirmed by gastroscopy underwent contrast-enhanced spectral CT imaging preoperatively.The monoergic and iodine-based images were obtained by GSI Viewer software,CT value and iodine concentration (IC)of the lesions were measured,and normalized iodine concentration (NIC)was calculated.With the reference of postoperative pathology,data were analyzed by LSD method of one-way analysis of variance.Results The IC,NIC,spectrum curve slope of 40-70 keV,40-140 keV and 70-140 keV energy range of intestinal type,mixed type and diffuse type carcinoma in the arterial phase were 12.86±6.80 (100 μg/mL),0.13±0.06 ,2.50±1.26 ,0.99±0.51 ,0.34±0.20 ,18.54±6.49 (100 μg/mL),0.19±0.07, 3.56±1.24,1.42±0.50,0.50±0.18 and 24.52±9.68 (100 μg/mL),0.24±0.09,4.73±1.76,1.90±0.73,0.68±0.29,respectively. The values of intestinal type were all significantly lower than those of diffuse type (P <0.05).Comparison between intestinal-mixed type and mixed-diffuse type,the other parameters were no significant differences except IC between intestinal-mixed type (P=0.037).Conclusion The slope of spectrum curve,iodine concentration,and normalized iodine concentration could be helpful for preoperative evaluation of Lauren classification of gastric cancer.