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.

ObjectiveTo explore the best measurement of waist circumference related with intra-abdominal fat volume evaluated by CT scan.MethodsHeight,weight,and hip circumference were measured among 147 subjects aged over 18 years old.Waist circumference was measured at 3 different levels:the upper brim of the iliac crest ( WC1 ),the midpoint between costal brim and iliac crest ( WC2 ),and the umbilicus ( WC3 ).The intra-abdominal fat volume was evaluated by CT scan.ResultsIntra-abdominal fat volume was significantly higher in men than in women [ ( 1 236.0±608.4 vs 931.0±665.0)cm3,P＜0.01 ].Correlation analysis showed that WC1 ( r =0.634),WC2( r=0.677),and WC3 (r =0.712)were positively correlated with intra-abdominal fat volume ( all P＜0.01 ).Partial correlation analysis adjusted by gender,weight,or body mass index showed that the correlation of intra-abdominal fat volume with WC3 ( r were 0.488 and 0.432) was better than that with WC1( r were 0.347 and 0.293 ) and WC2 ( r were 0.424 and 0.365 ).Multiple linear stepwise regression analysis demonstrated that WC2 and WC3 were independently associated with intra-abdominal fat volume and WC3 was the strongest impact factor (β =0.270,R2c =0.504,P＜0.01 ).ConclusionsWaist circumference is a simple anthropometric measurement parameter reflecting the degree of intraabdominal fat accumulation.All three different measurements of waist circumference may reflect intra-abdominal fat volume,while waist circumference at umbilical level is the best among them.

Objective To investigate the value of MR perfusion parameters and ADC in the diagnosis of pancreatic cancer and pancreatic mass at 3.0 T MR. Methods Twenty healthy volunteers and 25 patients with pancreatic cancers proven by pathological results underwent MR PWI at a 3.0 T scanner. A two-compartment model was used to quantify Ktrans, Kep and Ve in the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue. All parameters among different tissues were analyzed and compared with ANONA. Fifteen normal volunteers and 58 patients, including 30 patients with pancreatic cancer (proven histopathologically), 9 patients with pancreatitis pseudotumor (4 patients proven by histopathological results, 5 patients proven by follow-up after treatment), 9 patients with solid pseudopapillary tumor of pancreas (SPTP, proven histopathologically) and 10 patients with pancreatic neuroendocrine tumor (PET, proven by histopathology), underwent respiratory-triggered DWI on 3.0 T. ADC values of normal pancreas and all types of pancreatic lesions were statistically analyzed and compared with ANONA. ROC curve was used to analyze the diagnostic power of ADC value. Results Ktrans of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (1.66±1.25), (3.77±2.67),(1.16±0.94) and (2.69±1.46)/min respectively(F=8.160, P＜0.01). LSD test showed that Ktrans in the pancreatic cancer was statistically lower than that in normal pancreas (P=0.011)and adjacent pancreatic tissue(P=0.002). Kep of pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were (2.53±1.55), (5.64±2.64), (1.70±0.91) and (4.28±1.64)/min respectively(F=4.544, P＜0.01). LSD test revealed that Kep in pancreatic cancer was statistically lower than that in normal pancreatic tissue (P=0.035)and adjacent pancreatic tissue(P=0.041). The median of Ve among the pancreatic cancer, adjacent pancreatic tissue, distal inflammatory pancreatic tissue and normal pancreatic tissue were 0.926, 0.839, 0.798 and 0.659 respectively (χ2=12.040,P＜0.01). Ve in pancreatic cancer was statistically higher than that in normal pancreatic tissue (P=0.002). ADC values of the pancreatic cancer, pancreatitis pseudotumor, SPTP, PET and normal pancreas were(1.57±0.26)×10-3,(1.19±0.15)×10-3,(1.05±0.35)×10-3,(1.62±0.41)×10-3 and (1.82±0.25)×10-3 mm2/s(F=21.681, P＜0.01). LSD test showed there were significant statistical differences in ADC values among pancreatic cancer, pancreatitis pseudotumor and normal pancreatic tissue (P＜0.01). ROC curve disclosed that the sensitivity, specificity, positive predictive value and negative predictive value were 86.7%, 88.9%, 96.3% and 66.7% respectively, when ADC≥1.33×10-3 mm2/s was used as a cutoff value for differential diagnosis of PDCA from MLP. The sensitivity, specificity, positive predictive value and negative predictive value were 77.8%, 100.0%, 100.0% and 83.3% respectively when ADC≤1.25×10-3 mm2/s was used as a cutoff value for differential diagnosis of SPTP from PET. Conclusion Compared to normal pancreatic tissue, pancreatic cancer usually had a lower Ktrans, Kep and larger Ve. ADC values from respiratory-triggered DWI were well related to histopathological features of pancreatic entities and may be helpful in the differential diagnosis.

Objective To explore the effect on image quality and scanning time by changing parameters and using different scan-ning technique for the clinical application of axial FLAIR pulse sequence.Methods Seven different sets of parameters of T2-FLAIR Pulse Sequences were performed on thirty patients at a 3.0 T MR scanner.Group A was scanned with a routine sequence for refer-ence.Group B,reducing the matrix to 128.Group C,increasing the turbo factor parameter to 24.Group D,setting the contatena-tion to 1.Group E setting the Accel.factor PE to 4.Group F,using a BLADE-FLAIR sequence.Group G,using a HASTE-FLAIR sequence.The SNRs of all images were statistically analyzed by ANOVA among 7 sequences.The image quality of all images was statistically analyzed by Kruskal-Wallis test among 7 sequences.Results The SNR of seven groups of images were 54.69 ±8.12, 1 57.57±25.61,44.56±7.37,38.48 ± 9.32,44.1 9 ±8.79,45.60 ± 6.92,105.20 ± 18.25,respectively(F = 266.368,P =0.000). The scores of image quality were 3.87±0.09,2.50±0.12,3.72±0.1 6,3.10±0.10,1.88±0.10,3.92±0.07,2.08±0.10,re-spectively and the differences among groups were statistically significant(χ2 =1 93.361,P =0.000).Conclusion Suitable turto factor and BLADE technique can be the best option for FLAIR sequence in the head.HASTE-FLAIR sequence can act as the secondary op-tion for the uncooperative patients.

Objective To prepare gadolinium-loaded stearic acid grafted chitooligosaccharide (COSSA-DTPA-Gd) and evaluate its micelle properties,cytotoxicity,relaxation rate in vitro,and pancreatic tumor in vivo imaging.Methods Stear ic acid grafted chitooligosaccharide (COSSA) was synthesized by acetylation reaction between stearic acid and chitooligosaccharide.Diethylenetriaminepentaacetic dianhydride (DTPA) was conjugated to the residual amino groups of COSSA,then Gd3+ was chelated to obtain the final product.The micelle properties were measured using an electron microscopy and a laser particle sizer.The MTT assay was adopted to determine cytotoxicity.The in vitro relaxation rate and in vivo imaging of pancreatic tumor were evaluated using an MR scanner.Results COSSA-DTPA-Gd could self-assemble into stable micelles in aqueous solutions with a critical micelle concentration of (5.12±0.43)μg/ml.The micelles had positive charge and exhibited roughly spherical shape with a mean diameter of (58.3± 5.7)nm.The content of Gd3+ in COSSA-DTPA-Gd was 330.31 μmol/g.The nanoprobe and Magnevist,the commercial formulation,showed similar cytotoxicity (P＞0.05).The cell survival rate within 24 h were higher than 85％.The in vitro relaxation rate of COSSA-DTPA-Gd was 8.23 mM-1 ·s-1.After intravenous injection,COSSA-DTPA-Gd showed a better positive contrast-enhancing effect for pancreatic tumor than Magnevist.The MR images at the tumor periphery was rapidly enhanced,while a slow increase in image quality was observed in tumor core.Conclusion The prepared COSSA-DTPA-Gd can be used for efficient MR imaging of pancreatic tumor.

Objective To investigate the diagnostic value of different DWI sequences for pancreatic cancer on a 3.0 T MR scanner.Methods Different DWI acquisitions based on SE-EPI sequence were preoperatively performed in 30 patients with pancreatic cancer proven by histopathology on a 3.0 T MR scanner.The patients included 17 males and 13 females.Their age ranged from 39 to 72 years with mean of (57.6 ± 14.9) years.The b values were 0 and 600 s/mm2 and the following sequences were included:breath-hold DWI with MPG pulses in X,Y,Z direction (BH600ALL),breath-hold DWI with MPG pulses in Z direction(BH600SI),respiratory-triggered DWI with MPG pulses in X,Y,Z direction (TRIG600ALL),respiratory-triggered DWI with MPG pulses in X,Y,Z direction and inversion recovery for fat saturation (TRIG600ALL+FS) and free-breathing DWI with MPG pulses in X,Y,Z direction and inversion recovery for fat saturation (FB600ALL+ FS).C,CNR and ADC of pancreatic cancer were caculated and compared among different DWI sequences by statistic mathed.Results CNR (F =11.444,P ＜ 0.001) and C (F =5.447,P ＜ 0.05) of pancreatic cancer displayed noticeably statistical difference among BH600ALL、BH600SI、TRIG600ALL、TRIG600ALL + FS and FB600ALL + FS DWI sequences by ANOVA.Among those five different DWI sequences,the highest CRN of pancreatic cancer was observed in TRIG600ALL and TRIG600ALL + FS(the values were 16.45 ± 10.37 and 13.38 ± 9.10 respectively),while the highest C of pancreatic cancer was noticed in TRIG600ALL + FS (0.39 ±0.15).ADC of pancreatic cancer had no statistical difference among BH600ALL,BH600SI,TRIG600ALL,TRIG600ALL + FS and FB600ALL + FS DWI sequences by Kruskal-Wallis test.For BH600ALL and BH600SI,there were no statistical difference among ADC of pancreatic cancer,adjacent pancreatic tissue and distal pancreatitis by ANOVA.While for all TRIG600ALL,TRIG600ALL + FS and FB600ALL + FS,there were statistical difference among ADC of pancreatic cancer,adjacent pancreatic tissue and distal pancreatitis by ANOVA (F values were 5.353,15.976 and 14.556 respectively,P ＜ 0.05).ADC of pancreatic cancer was statistically lower than that of adjacent pancreatic tissue and distal pancrcatitis on all TRIG600ALL,TRIG600ALL + FS and FB600ALL +FS (P ＜ 0.05).Conelusion Compared to other four DWI sequences,TRIG600ALL + FS had higher C and CNR in pancreatic cancer,and measurement of ADC value was helpful to disclose the histopathological state in pancreatic cancer,adjacent pancreatic tissue and distal pancreatitis.

Objective To compare the hemodynamics features of recurrent hepatocellular carcinoma between contrast-enhanced ultrasonography (CEUS) and contrast-enhanced MRI (CEMRI).Methods Forty three recurrent hepatocellular carcinoma lesions in 39 patients were evaluated by CEUS and CEMRI.All lesions were proved by operation or needle biopsy.The dynamic enhancement and washout process on CEUS and CEMRI were analyzed.Results On both two methods,all lesions showed hyperenhancement.Among which,30.2％ (13/43) lesions showed hyperenhancement during arterial phase and no washout was found during portal venous phase,37.2 ％ (16/43) lesions hyperenhanced during arterial phase and washout during portal venous phase.During late phase,the enhancement of 60.5％ (26/43) lesions decreased and 7.0％ (3/43) lesions showed no washout on CEUS or CEMRI.The overall concordance ratio between two methods was 67.4％ (29/43).Difference of hemodynamics features between CEUS and CEMRI was not statistically significant.Conclusions CEUS can accurately display the hemodynamic features of recurrent hepatocellular carcinoma,and enjoy high consistence with CEMRI.

Objective To evaluate the imaging quality of the non-contrast enhanced MR angiography of sampling perfection with application optimized contrasts using different flip angle evolutions (SPACE)in showing portal system and compared it with that of the contrast enhanced MR angiography of volumetric interpolated breath-hold examination (VIBE),and study its diagnostic ability in the detection of portosystemic and portohepatic collaterals.Methods Thirty consecutively cirrhotic patients with suspected of portosystemic and portohepatic collaterals were enrolled,and underwent SPACE followed by VIBE at 1.5 T MR scanner.The diagnostic accuracy of SPACE for the portal vein disease was evaluated by two doctors and compared it with that of VIBE.The contrast-to-noise ratio(CNR) and signal-to-noise ratio(SNR) of two MRA techniques were compared by using the Wilcoxon signed rank test.The quality assessment including scores of the portal vein segments and overall image quality were used the paired t test.Results Twenty-one patients were diagnosed as portal hypertension,including five types of portosystemic collaterals: esophageal varices (n =5),gastric fundic varices (n =11),splenic varices (n =5),paraumbilical varices (n =5) and cavemous transformation (n =2),and one patient was diagnosed as portal vein tumor thrombus.The diagnostic efficiency of SPACE was equivalent to that of VIBE.In SPACE,the SNR were 291 ± 57,301 ± 74,344 ±76 and the CNR were 231 ±59,242 ±73,286 ±76 at main portal vein,the left branch of portal vein and the right branch of portal vein,respectively.However in VIBE,the SNR were 185 ± 56,176 ± 52,182 ±52 and the CNR were 57 ±23,50 ±21,57± 19 at,respectively.Both SNR and CNR of portal vein segments in the former were better than those in the latter (t values were 7.691,7.418,7.946,15.746,13.508 and 13.880,respectively,P ＜ 0.05).There were no significant difference for the scores of displaying main,left branch and right branch portal vein and overall image quality in VIBE and SPACE (Z values were -1.496,-1.895,-1.496,-2.138,-2.324 and-1.328,respectively,P ＞ 0.05).The scores of displaying the distal branches of left and right portal vein were 2.08 ± 0.78,2.08 ± 0.78 in SPACE,and 1.75 ± 0.53,1.71 ± 0.55 in VIBE,respectively.It was better (Z =-2.138,-2.324,P ＜ 0.05) in SPACE than that in VIBE.Conclusion The SPACE has better visualization of portal vein distal branches than VIBE,and it can be applied for the diagnosis of the portal vein disease.

Objective To determine the clinical value of hypergammaglobulinemia as a sentinel for autoimmune pancreatitis and avoid unnecessary pancreas resection.Methods All 14 patients with autoimmune pancreatitis or related pancreatic diseases underwent routine examinations,including liver function,CA199 and imaging.Measurement of serum IgG or IgG4 was performed for patients with clinically suspected or pathologically proved autoimmune pancreatitis.Clinical features were retrospectively compared between the AIP and non-AIP patients using x2 statistics with Yates correction or Fisher exact test.Results Ten cases were finally confirmed as autoimmune pancreatitis.All patients with autoimmune pancreatitis had elevated levels of serum γ-globulins,while only one case without autoimmune pancreatitis had elevated levels of serum γ-globulins.It was proved by subsequent antibody tests that serum IgG/IgG4 and γ-globulins were simultaneously increased.Conclusions Hypergammaglobulinemia can be used as a preoperative sentinel indicator for differentiating autoimmune pancreatitis from pancreatic malignancies and avoiding unnecessary pancreas operation.

Objective To study the association of liver fat content (LFC) with insulin resistance and β cell function. Methods One hundred and nine subjects including 31 cases with impaired glucose regulation (IGR), 31 newly diagnosed type 2 diabetes (NT2DM) and 47 normal controls (NC) with normal metabolic parameters were involved in the study. LFC was measured by 1H magnetic resonance spectroscopy (1H MRS) and the insulin resistance and β cell function were evaluated by oral 75 g glucose tolerance test. Results (1 ) LFCs were3.83% (2.35% ～7.59% ) ,12. 82% (8.10%～21.37%), and 21.99% (11.89%～34.43%), being progressively raised in the respective NC, IGR, NT2DM groups(P<0.01). (2) The subjects were divided into four subgroups according to LFC Quartile: Quartile 1 (LFC<4. 04% ) , Quartile 2(4. 04% ≤LFC<9. 77% ), Quartile 3 (9.77% ≤LFC<20.78% ) ,and Quartile 4( LFC≥20.78% ). Homeostasis model assessment of insulin resistance index (HOMA-IR) values were elevated significantly and progressively starting from Quartile 2(P<0. 01). (3) Insulin from 0 to 30 min ( △I30), the ratio of insulin from 0 to 30 min to glucose from 0 to 30 min ( △I30/ △G30) , C peptide from 0 to 30 min (△CP30) had a trend of increase in Quartile 2,then trended to decrease in Quartile 3. In Quartile 4, △CP30 and △I30/△G30 sharply decreased (P<0.05 or P<0.01). The ratio of C peptide from 0 to 30 min to glucose from 0 to 30 min ( △CP30/△G30) began to decrease from Quartile 3 (P<0. 05). The ratio of area under curve of C peptide to area under curve of glucose (CPAUC/GAUC) was significantly decreased from Quartile 3(P<0.05). From Quartile 3,glucose level became abnormally elevated to impaired fasting glucose and impaired glucose tolerance (P<0.01). (4) LFC was positively correlated with HOMA-IR (rs =0. 618 ,P<0.01), but was negatively correlated with △CP30(rs =-0.282), △CP30/△G30(rs = -0. 404), and CPAUC/GAUC(rs = -0. 308,all P<0.01). (5) Stepwise regression analysis demonstrated that LFC was the strongest predictor of HOMA-IR. Conclusions When LFC accumulated to 4% , insulin resistance occurred and the early phase of insulin secretion was compensatively increased. As the LFC further accumulated to 10% , both the early phase as well as β cell function in whole were deteriorated, and hyperglycemia developed.