Objective To evaluate which b value is the best to distinguish the glioma recurrence and radiation-induced brain injury using DWI when b value were at 1 000 s/mm2、3 000 s/mm2 and 5 000 s/mm2 respectively.Methods Retrospective analysis the DWI of 21 patients who suffered from glioma recurrence and radiation-induced brain injury obtained on a 3T MRI scanner.Results (1)All recurrent glioma (100%)showed hyper-intense signal,while most radiation-induced brain injury patients (80%)showed hypo-in-tense signal when b=5 000 s/mm2 .The sensitivity and specificity were high (100% and 80% respectively)when hyper-intense sig-nal was taken as a diagnostic point of glioma recurrence and radiation-induced brain injury.(2)The receiver operating characteristic (ROC)curve analysis suggested that the minimum ADC resulted in a highest sensitivity to differentiate glioma recurrence from radi-ation-induced brain injury when b=5 000 s/mm.Conclusion High b-value is more accurate to reflect cell density,and the minimum ADC is better to differentiate the glioma recurrence and radiation-induced brain injury when b=5 000 s/mm2 on DWI.

Objective To investigate the diagnosis value of 128-slice spiral CT in patients with adult intussusception. Methods Direct features of 128-slice spiral CT of 63 adult intussusception patients confirmed by operation and pathology were analyzed retrospectively. Results In 63 cases of intussusceptions, 1 case had idiopathic intussusception, and the other 62 cases had secondary intussusception (1 case with multiple intussusceptions). Direct signs included:target signin 60 cases,double intestines signin 59 cases,blood vessel curling signin 56 cases, andcomet-tail signandkidney signin 51 cases. Lipoma was the most common benign lesions of intussusception, and colon cancer was the most common malignant lesions of intussusception. Conclusions The 128-slice spiral CT combined with multiple plane restructuring has the important value in diagnosing adult intussusception.

Objective To explore the optimal situation of labeling bone mesenchymal stem cells (BMSCs) with superparamagnetic iron oxides (SPIO) mediated by poly-L-lysine (PLL), and determine the most optimal protocol of magnetic resonance imaging according to the patterns of MR in vitro. Methods BMSCs were isolated from white rat and purified, incubated with SPIO-PLL complexes at the range of concentrations (0, 4.2, 8.4, 21, 42, 84 ?g Fe per ml medium). The labeling ratio and distribution of SPIO particles in BMSCs, and the morphological evidence of abnormal visualization were evaluated by Prussian blue staining, fluorescent microscope and electron microscopy. MTT growth curves and magnetic resonance imagings were obtained at the range of concentrations. Trypan blue exclusion test was performed to elevate the viability of BMSCs labeled with PLL at the range of concentrations (0, 0.05, 0.25, 0.5, 1.0, 5.0 ?g PLL per ml medium). Results The cellular labeling ratio was strongly correlated to the concentrations of SPIO (P

Objective To explore the sensitivity of a little amount of subarachnoid hemorrhage (SAH) between CT and different MR sequences through animal experiment,to find a more sensitive way to diagnosis SAH.Methods 18 healthy adult white New Zealand rabbits were randomly divided into two experimental groups(group A and group B) and one control group(group C).Rabbit SAH model was established by injecting blood into the cisterna magna one time.All rabbits underwent CT and MR scan at 2 hours,48 hours after operation.The findings on CT and different MR sequences were observed and recorded.Results ①In experimental groups(group A and group B),MR FLAIR sequences in the diagnosis of a little amount of SAH was more sensitive than that on MR T1WI,T2WI and CT in acute phase.And the diagnosis sensitivity between MR FLAIR and CT was statistically significant(P<0.05).②Abnormal signs of SAH could not be found in group C.Conclusion ①Rabbit SAH model was established successfully which will be the foundation for the follow-up study of medical imaging.②MR FLAIR sequence is more sensitive to diagnose a little amount of SAH in acute phase,and may be used in the routine diagnosis of SAH in acute phase.

Objective To study the severity of acute pancreatitis (AP) by using MRI and the acute physiology and chronic healthy evaluation Ⅲ (APACHE Ⅲ ) score, and the correlation between corresponding MRI findings and APACHE Ⅲ scores.Methods One hundred patients with AP undergoing abdominal MRI were recruited in the study. The MRI features of acute pancreatitis were recorded. The severity of AP on MRI was graded by MR severity index (MRSI) as mild (0 to 2 points),moderate ( 3 to 6 points) and severe (7 to 10 points).APACHE Ⅲ score was denoted for AP was as mild ( ＜35 points)and severe ( ≥ 35 points).The local and systematic complications,mortality,need to intense care unit (ICU),and hospitalization time were recorded and compared with MRSI and APACHE Ⅲ score.Nonparametric Spearman correlation was calculated for testing the correlation between the MRSI,the APACHE Ⅲ and hospitalization time.The correlation of clinical results with MRSI and APACHE Ⅲ was calculated by x2 test.Results In the 100 patients with AP,there were respectively 80 and 20 patients with edematous and necrotic pancreatitis on MRI.According to MRSI,34,59 and 7 patients had mild,moderate,and severe acute pancreatitis,respectively.The APACHE Ⅲ score was (24.9 ± 12.2) points.Seventy-seven patients had less than 35 points and 23 patients had more than 35 point of APACHE Ⅲ score.There were significant differences in the local complication,systematic complication,need to ICU among the three groups in MRSI score,respectively( x2 =9.161,19.118,54.767;P ＜ 0.01 ).There was difference in the systematic complication between mild and severe AP in APACHE Ⅲ score(x2 =13.120,P =0.000),but there were no differences (x2 =0.245,x2 =2.568;P ＞ 0.05) in the local complication,need to ICU between mild and severe AP in APACHE Ⅲ score.There was weak correlation ( r =0.235,P =0.019 )between MRSI score and hospitalization time,and no difference (r =0.168,0.105; P ＞ 0.05)between APACHE Ⅲ and MRSI,APACHE Ⅲ and hospitalization time,respectively.Conclusions Both MRSI and APACHE Ⅲ score may predict systematic complications. However,MRSI is superior to APACHE Ⅲ in predicting the local complications,need to ICU,and hospitalization time in patients with acute pancreatitis.

Objective To characterize pancreatic perfusion in swines with experimental chronic pancreatitis(CP)by dynamic contrast-enhanced MRI and to correlate it with the severity of CP.Methods Twenty-two swines were randomly selected and made CP by ligation of main pancreatic duct.Six healthy swines served as control.MR perfusion study with dynamic contrast-enhanced MRl was carried out on the swines under anesthesia.The animals were euthanized after MR perfusion exam.The swines were divided into 4 groups according to the histological results of pancreas:normal group,group of CP of grade 1,group of CP of grade 2,and group of CP of grade 3.The maximum perfusion slope rate,the time-to-peak value and the maximum enhancement rate was compared between the groups using variance analysis,and the relationship between each perfusion parameters and severity of CP was made by correlative analysis.Results Twenty-one swines underwent MR perfusion study,including 7 swines in normal group,7 in group of grade 1 CP,3 in group of grade 2 CP,and 4 in group of grade 3 CP.On signal intensity time curve(SI-T)derived from MR perfusion weighted imaging,the m~imum slope rate was(10.88±1.20)%,(10.59±1.02)%,(6.67±1.31)%,and(5.48±1.97)%for normal swines,swines with grade 1 CP,swines with grade 2 CP and swines with grade 3 CP,respectively(F=20.51,P＜0.05).The time-to-peak value was(13.82±3.09)s,(12.31±5.52)s,(20.55±3.79)s and(37.26±14.56)s respectively(F=10.68,P＜0.05).The maximal signal enhancement rate was(62.95±20.20)%,(60.44±20.00)%,(46.33±22.70)%,and(67.65±32.66)%,respectively(F=0.53,P＞0.05).The highest slope value(r=-0.72,P＜0.05)and the time-to-peak(r=0.54,P＜0.05)of the SI-T curve were correlated to the severity of CP,respectively.However there was no linear correlation between the maximal signal enhancement rate and the severity of CP.Conclusion MR perfasion weighted imaging has a potential to diagnose and to grade experimental chronic pancreatitis.

Objective To study MRI findings of pancreatic ducts of piglets with chronic pancreatitis (CP) induced by pancreatic duct ligation and analyze the relationship between pancreatic duct changes in piglets with CP and the pathological severity of CP. Methods Thirty healthy piglets were included in this study. Five piglets were randomly selected as normal control group, and the remaining 25 piglets were served as the experimental group. The duct ligation operations were performed on experimental group. After 2 to 18 weeks, pancreas and pancreatic ducts were observed on MRI. Then the pancreas was removed and graded into three types by histopathology. The relationship between the diameter of pancreatic duct or the pancreatic branch displaying rate and the severity of CP was analyzed by Spearman correlation coefficient. Results CP was found in 21 piglets( 84. 0% ) in the experimental group including mild ( n = 7 ), moderate ( n = 8 ) and severe( n = 6) pancreatitis. Pancreatic ducts were shown in mild CP and the edge of pancreatic ducts was irregular in three cases. The dilated RPD, LPD and MPD constituted the "person" form in moderate and severe CP. The diameter of pancreatic ducts was(0. 9 ±0. 3)mm, (2. 9 ± 1.4)mm and (4. 8 ± 1.2)mm in mild, moderate, and severe CP respectively. The expansion extent of pancreatic ducts was correlated with the severity of CP of piglets (r = 0. 837, P ＜ 0. 05). The pancreatic branch displaying rate increased with the increase of the severity of CP ( r = 0. 990, P ＜ 0. 05 ); the displaying rate was 0/7 for mild, 3/8 for moderate, and 5/6 for severe CP. Conclusions The dilated pancreatic ducts with "person" form in piglets with obstructive CP created by pancreatic duct ligation. The pancreatic duct changes on MRI reflect the severity of CP of piglets.

Objective To screen and identify the phage-display random 7 amino acid peptide specific to the systemic lupus erythematosus(SLE) and analyze its practical significance. Methods Using the phage random 7 peptide library screening, the SLE specific phage clones are obtained after binding with the mixture of sera from 30 SLE patients and 30 normal controls as ligand respectively. Then the Dot-ELISA is used to identify the SLE specific phage clones reactive to sera of the SLE patients and normal controls individually. Finally the identified phage-display random 7 amino acid peptides are sequenced and it's homology with the antigenic epitope of human being and other are also analyzed. Results Total 12 of the phage-display random 7 amino acid peptide are obtained by phage peptide library screening and the Dot-ELISA identification. Sequence analysis shows that the identified phage-display random 7 amino acid peptide epitope have homology with E. coli, Salmonella and human immunodeficiency virus, but not with that of human being. Conclusion SLE-specific peptides screened by phage random peptide library maybe used to diagnosis the SLE. Meanwhile, the antibodies in SLE patients which are combined with the Pathogen epitope, suggest that SLE maybe relate to pathogen infection.

Objective To explore the value of pelvic fascia changes after high intensity focused ultrasound (HIFU) ablation of uterine fibroids patients with MRI.Methods The pelvic MRI and clinical data of 283 patients with uterine fibroids after treatment of HIFU were analyzed retrospectively.The total power and irradiation time of HIFU,and the degree of pelvic fascia edema changes were observed.The correlation between age,fibroids location,type,number,volume,total energy,irradiation time of HIFU and the degree of pelvic fascia edema were analyzed.Results Totally 201 patients (201/283,71.02％) had pelvic fascia edema and 59.71％ (169/283) were degree 1 and 2.There was significant difference in the degree of pelvic fascia edema in patients with different fibroids (x2 =27.50,P=0.007).There was no correlation between patients age,number,volume,type of fibroids,nor pelvic fascia edema (all P＞0.05).HIFU energy and irradiation time were positively correlated with the degree of pelvic fascia edema (rs =0.288,0.317,both P＜0.001).Conclusion MRI can observe pelvic fascia edema caused by HIFU treatment of uterine fibroids.HIFU irradiation time,total energy,and location of uterine fibroids location are the main influencing factors.

Objective: To investigate the diagnostic value of multimodal magnetic resonance imaging (MRI) in primary central nervous system lymphoma (PCNSL). Methods: The multimodal MRI findings of 16 patients with PCNSL confirmed by histopathology from January 2016 to December 2018 in Affiliated Hospital of North Sichuan Medical College were retrospectively analyzed. Routine MRI plain scan, enhancement, diffusion weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) examination were performed in all cases. Results: All 16 patients were diagnosed with diffuse large B cell non-Hodgkin lymphoma. There were 7 cases with solitary lesions and 9 cases with multiple lesions. A total of 36 lesions were detected, with 30 above and 6 below the curtain. Sixteen lesions were located in the deep white matter near the ventricle (among which 2 lesions involved the corpus callosum), 5 lesions in the superficial cerebral hemisphere, 7 lesions in basal ganglia, 2 lesions in thalamus, 3 lesions in cerebellum, and 3 lesions were in brainstem. T₁WI showed equal or slightly low signal, and T₂WI showed equal or slightly high signal. There was different degree of edema around the lesions. 32 lesions were mild to moderate, and 4 lesions were severe. On enhancement scanning, 31 lesions showed patchy, nodular or lumpy uniform enhancement; 5 lesions showed irregular annular enhancement. "Incision" was found in 12 lesions, and "angular" was found in 7 lesions. Obvious enhancement of adjacent meninges or ependymal membranes occurred in 1 case each. DWI showed 29 high signals in the focal areas and 7 equal or slightly high signals, and all apparent dispersion coefficient (ADC) values were reduced. MRS showed that choline peak increased, and N-acetyl aspartate (NAA) peak and creatine peak decreased in all cases. highly elevated lipid peak was observed in 8 cases, inverted lactic acid peak in 3 cases, and both lipid peak and lactic acid peak were observed in 2 cases. Conclusions Multimodal MRI can reflect the characteristics of PCNSL from different aspects, which is of great value in improving the diagnostic accuracy of PCNSL.