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Objective:To develop and validate the models based on mixed enhanced computed tomography (CT) radiomics and deep learning features, and evaluate the efficacy for differentiating pancreatic adenosquamous carcinoma (PASC) from pancreatic ductal adenocarcinoma (PDAC) before surgery.Methods:The clinical data of 201 patients with surgically resected and histopathologically confirmed PASC (PASC group) and 332 patients with surgically resected histopathologically confirmed PDAC (PDAC group) who underwent enhanced CT within 1 month before surgery in the First Affiliated Hospital of Naval Medical University from January 2011 to December 2020 were retrospectively collected. The patients were chronologically divided into a training set (treated between January 2011 and January 2018, 156 patients with PASC and 241 patients with PDAC) and a validation set (treated between February 2018 and December 2020, 45 patients with PASC and 91 patients with PDAC) according to the international consensus on the predictive model. The nnU-Net model was used for pancreatic tumor automatic segmentation, the clinical and CT images were evaluated, and radiomics features and deep learning features during portal vein phase were extracted; then the features were dimensionally reduced and screened. Binary logistic analysis was performed to develop the clinical, radiomics and deep learning models in the training set. The models' performances were determined by area under the ROC curve (AUC), sensitivity, specificity, accuracy, and decision curve analysis (DCA).Results:Significant differences were observed in tumor size, ring-enhancement, upstream pancreatic parenchymal atrophy and cystic degeneration of tumor both in PASC and PDAC group in the training and validation set (all P value <0.05). The multivariable logistic regression analysis showed the tumor size, ring-enhancement, dilation of the common bile duct and upstream pancreatic parenchymal atrophy were associated with PASC significantly in the clinical model. The ring-enhancement, dilation of the common bile duct, upstream pancreatic parenchymal atrophy and radiomics score were associated with PASC significantly in the radiomics model. The ring-enhancement, upstream pancreatic parenchymal atrophy and deep learning score were associated with PASC significantly in the deep learning model. The diagnostic efficacy of the deep learning model was highest, and the AUC, sensitivity, specificity, and accuracy of the deep learning model was 0.86 (95% CI 0.82-0.90), 75.00%, 84.23%, and 80.60% and those of clinical and radiomics models were 0.81 (95% CI 0.76-0.85), 62.18%, 85.89%, 76.57% and 0.84 (95% CI 0.80-0.88), 73.08%, 82.16%, 78.59% in the training set. In the validation set, the area AUC, sensitivity, specificity, and accuracy of deep learning model were 0.78 (95% CI 0.67-0.84), 68.89%, 78.02% and 75.00%, those of clinical and radiomics were 0.72 (95% CI 0.63-0.81), 77.78%, 59.34%, 65.44% and 0.75 (95% CI 0.66-0.84), 86.67%, 56.04%, 66.18%. The DCA in the training and validation sets showed that if the threshold probabilities were >0.05 and >0.1, respectively, using the deep learning model to distinguish PASC from PDAC was more beneficial for the patients than the treat-all-patients as having PDAC scheme or the treat-all-patients as having PASC scheme. Conclusions:The deep learning model based on CT automatic image segmentation of pancreatic neoplasm could effectively differentiate PASC from PDAC, and provide a new non-invasive method for confirming PASC before surgery.
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Objective:To explore the value of 3.0 T high resolution MRI (HR-MRI) in the follow-up of drug treatment in acute and non-acute ischemic stroke caused by middle cerebral artery (MCA) plaque.Methods:The perspective study enrolled patients with ischemic stroke caused by MCA stenosis from October 2012 to October 2015 in the department of Neurology and Neurosurgery of Changhai Hospital Affiliated to Naval Medical University. All the patients underwent HR-MRI and then were divided into acute and non-acute stroke groups according to the intervels of the last symptom onset to the time of HR-MRI examination. All patients were informed consent to receive antiplatelet drug and intensive lipid therapy and followed up with HR-MRI. The HR-MRI sequence including T 2WI, T 1WI and contrast-enhanced T 1WI of vessel wall, and T 2WI and DWI of brain were routinely performed. T-test of paired samples was used to evaluate the changes of stenosis rate of vascular lumen, plaque enhancement degree, plaque volume and plaque burden on HR-MRI, and the NIHSS score of nervous system and blood biochemical indicators of the patients before and after treatment. Chi square test was used to compare the difference in ischemic event recurrcence between the acute and the non-acute stroke group. Results:A total of 31 acute stroke patients and 20 non-acute stroke patients were enrolled in the study. The mean follow-up time of acute stroke group was (671.71±522.86) days. Compare with the baseline, the stenosis rate of vascular lumen ( P=0.039), plaque enhancement degree ( P<0.001), plaque volume ( P=0.024) and plaque burden ( P=0.031) were all improved after the drug treatment, the NIHSS score of nervous system was also significantly improved, and the levels of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) in 12 patients were significantly decreased. The mean follow-up time of patients with non-acute stroke was (695.35±555.90) days. The stenosis rate of vascular lumen, plaque enhancement degree, plaque volume and plaque burden were slightly improved, but without statistical significance ( P>0.05). There were no significant changes in NIHSS score of nervous system, TC, triglyceride (TG) and LDL-C ( P>0.05), however the high density lipoprotein cholesterol (HDL-C) was significantly increased than that in the baseline ( P=0.02). During the follow-up period, no new cerebral infarction was found in the DWI images of the two groups. Six patients had transient ischemic attack (TIA) recurrence in the acute stroke group and 5 patients in the non-acute stroke group, there was no significant difference between both groups(χ 2=0.229, P= 0.632). Conclusion:HR-MRI can be used as an important evaluation method for the follow-up of MCA atherosclerotic plaque therapy. After antiplatelet therapy and intensive lipid-lowering therapy, the plaque volume and burden of MCA offending plaque, and plaque enhancement decreased in acute stroke patients but there was no significant change in non-acute patients.
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Objective@#To investigate the characteristics of histogram analysis and differences of apparent diffusion coefficient (ADC) for normal pancreas with different diffusion gradients of diffusion weighted imaging (DWI) at 3.0T.@*Methods@#Three unidirectional diffusion gradients (X, Y or Z direction) and three orthogonal diffusion gradient DWI data of 21 volunteers with normal pancreas were retrospectively analyzed. The histogram parameters of mean ADC, percentile, skewness, peak and the like were measured based on home-made DWI post-processing software, and the differences on histogram parameters obtained from 4 different diffusion gradients were compared by using Kruskal Wallis test.@*Results@#There was no significant difference on the mean ADC, skewness, percentile and the like for normal pancreas among 3 unidirectional diffusion gradients and tri-orthogonal diffusion gradient DWIs, but there was significant difference on the mean kurtosis value (X: 3.16±1.44, Y: 4.72±2.26, Z: 4.47±2.1, tri-orthogonal: 3.69±1.82; χ2 =-9.84, P=0.02). Further analyses results showed that the ADC kurtosis of normal pancreas obtained from X-directional diffusion gradient DWI was significantly smaller than that of the direction of Y or Z, and the difference was statistically significant (P<0.05).@*Conclusions@#The ADC kurtosis of normal pancreas is related to the direction of diffusion gradient in DWI, and the ADC kurtosis of normal pancreas obtained by X-direction diffusion gradient is the smallest.
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Objective To investigate the characteristics of histogram analysis and differences of apparent diffusion coefficient ( ADC) for normal pancreas with different diffusion gradients of diffusion weighted imaging (DWI) at 3. 0T. Methods Three unidirectional diffusion gradients (X, Y or Z direction) and three orthogonal diffusion gradient DWI data of 21 volunteers with normal pancreas were retrospectively analyzed. The histogram parameters of mean ADC, percentile, skewness, peak and the like were measured based on home-made DWI post-processing software, and the differences on histogram parameters obtained from 4 different diffusion gradients were compared by using Kruskal Wallis test. Results There was no significant difference on the mean ADC, skewness, percentile and the like for normal pancreas among 3 unidirectional diffusion gradients and tri-orthogonal diffusion gradient DWIs, but there was significant difference on the mean kurtosis value ( X:3. 16 ± 1. 44, Y:4. 72 ± 2. 26, Z:4. 47 ± 2. 1, tri-orthogonal:3. 69 ± 1. 82; χ2 = -9. 84, P=0. 02). Further analyses results showed that the ADC kurtosis of normal pancreas obtained from X-directional diffusion gradient DWI was significantly smaller than that of the direction of Y or Z, and the difference was statistically significant (P<0.05). Conclusions The ADC kurtosis of normal pancreas is related to the direction of diffusion gradient in DWI, and the ADC kurtosis of normal pancreas obtained by X-direction diffusion gradient is the smallest.
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Objective To investigate the influencing factor of the morphology of unruptured intracranial aneurysms for aneurysm wall enhancement under the high-resolution magnetic resonance imaging. Methods From January 2015 to December 2016,the clinical and imaging data of 68 consecutive patients with unruptured intracranial aneurysm (86 aneurysms) in Changhai Hospital,the Second Military Medical University were enrolled retrospectively. Vascular wall imaging technology was used to conduct aneurysm scan,and the aneurysm wall enhancement was identified by the imaging features before and after contrast enhancement. They were divided into either an enhancement group ( n=32,34 aneurysms) or a non-enhancement group (n=45,52 aneurysms) according to whether having the abnormal enhancement of aneurysm wall or not ( because some patients also have enhanced aneurysms and non-enhanced aneurysms, the number of cases of the enhanced or not was calculated seperately in both groups ) . Morphological parameters were calculated by 3D image data,including aneurysm size,ratio of height to width,volume ratio, dome-to-neck ratio, transverse length ratio, bottleneck factor, and inflow angle. Univariate and multivariate logistic analyses were used to determine the morphological influence factors of aneurysm wall enhancement. Results (1) A total of 34 (39. 5%) aneurysms had aneurysm wall enhancement and 52 (60. 5％) aneurysms did not have aneurysm wall enhancement. There were no significant differences in sex, age, hypertension,diabetes, smoking, family history of subarachnoid hemorrhage, and aneurysm site in both groups (all P>0. 05). (2) The aneurysm size,ratio of height to width,volume ratio,dome-to-neck ratio, and bottleneck factor in the enhancement group were larger than those of the non-enhancement group. There were significant differences between the 2 groups (9. 19 [6. 54,11. 04] mm vs. 5. 31 [4. 17,7. 37] mm, (1. 18 [1. 01,1. 69] vs. 0. 91 [0. 72,1. 25],(3. 62 [2. 30,4. 63] vs. 2. 18 [1. 37,2. 76],1. 52 [1. 25, 1. 99] vs. 1. 19 [1. 03,1. 51],and 1. 21 [1. 11,1. 69] vs. 1. 05 [0. 94,1. 31],all P<0. 01). The proportion of irregular morphologic aneurysms in the enhancement group was higher than that in the non-enhancement group. There was significant difference between the 2 groups (55. 9％ [19/34] vs. 17. 3％ [9/52],P<0. 01 ) . There were no significant differences in transverse length ratio and inflow angle between the 2 groups (all P>0. 05). (3) Because the ratio of height to width,volume ratio,dome-to-neck ratio,and bottleneck factor were related to the aneurysm size,the aneurysm size,inflow angle,and irregular shape were included in the multivariate logistic regression analysis. The results showed that aneurysm size ( OR,3. 727,95％CI 1. 933-6. 971,P<0. 01) and irregular shape (OR,3. 990,95％CI 1. 219-13. 065,P=0. 022) were the independent risk factors for aneurysm wall enhancement. Conclusions The size and irregular shape of unruptured intracranial aneurysms are the independent risk factors for aneurysm wall enhancement. High-resolution magnetic resonance wall imaging may become an effective and noninvasive imaging method for evaluating the ruptured risk of intracranial aneurysms.
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Objective To study the value of reduced field-of-view (rFOV DWI) in differentiating patients with solid pancreatic focal lesions.Methods 139 patients with solid pancreatic mass were enrolled,including 105 patients with pancreatic ductal acinar carcinoma (PDAC),16 patients with neuroendocrine neoplasms,7 patients with mass forming chronic pancreatitis (MFCP) and 11 patients with solid papillary tumor (SPT).38 healthy adult volunteers served as controls,and underwent single stimulated echo planar imaging (ss-EPI) DWI and rFOV DWI(b value =0 and 600 s/mm2) MRI examination.Quartation method was used to evaluate the image quality of ss-EPI) DWI and rFOV DWI in the three terms of the visibility of anatomical structure,contrast of pancreatic lesions,motion and the susceptibility artifacts during MRI.Work station self-carried software was used to measure the ADC value of the region of interest (ROI).The image quality and ADC values of different pancreatic diseases and normal pancreas were compared.ROC curve for ADC value was drawn to evaluate the difference among PDAC,other benign pancreatic masses and normal pancreas.Results At b value of 0 and 600 s/mm2,rFOV DWI was superior to ss-EPI DWI in terms of showing pancreatic anatomic structure,the contrast of the lesion and the score evaluation for susceptibility artifacts(b =0 s/mm22.99 ±0.51 vs 2.79 ±0.64,2.37±0.48 vs 1.81 ±0.63,3.17 ±0.56 vs 2.91 ±0.60;b =600 s/mm23.63 ±0.50 vs 3.32 ±0.56,3.45 ±0.50 vs 3.01 ±0.49,3.74 ±0.44 vs 3.12 ±0.37),and the differences were statistically significant (P＜0.001).ADC values of PDAC,NET,MFCP,SPT and normal pancreas were (1.38 ± 0.17) × 10-3,(1.22 ± 0.35) × 10-3,(1.29 ± 0.13) × 10-3,(1.04 ± 0.38) ×10-3and(1.86±0.15) ×10-3mm2/sforrFOV DWI,and (1.73 ± 0.24) ×10-3,(1.63±0.39) ×10-3,(1.58±0.19) × 10-3,(1.25±0.26) × 10-3 and(2.04±0.20) × 10-3mm2/s for ss-EPI DWI.The difference on ADC values among different groups and within one group were all statistically significant (P ＜0.001).There were no statistical significant differences on ADC values between MFCP and PDAC,between MFCP and SPT as well as on ss-EPI DWI ADC values between PDAC and NET,but statistical differences were found between other two groups (P ＜ 0.05).The area under the ROC curve of rFOV and ssEPI DWI was 0.983 (95％ CI 0.944-0.998) and 0.889 (95％ CI 0.822-0.936),respectively,and the difference was statistically significant (P =0.0004),but rFOV DWI and ss-EPI DWI ADC values for PDAC and all benign solid diseases were 0.799 (95％ CI 0.719-0.864) and 0.755 (95％ CI 0.672-0.827),and the difference was not statistically significant.Conclusions rFOV DWI could significantly enhance the quality of DWI images,and its diagnostic efficacy was much better than ss-EPI DWI.
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Objective To investigate the application of MRI targeting contrast agent ( P-Gd-Probe) for P selectin in evaluating the severity grades of acute pancreatitis (AP).Methods L-arginine solution (100mg/100kg) were intraperitoneally injected for 3 times once an hour to establish AP model in SD rats. Control group was injected with normal saline in a equal volume .All rats were divided into acute edematous pancreatitis (AEP) group (6 h and 12 h after model establishment)and acute necrotizing pancreatitis (ANP) group (24 h and 48 h after model establishment ) based on the pathology .The rats were examined by T 1 WI plain and enhanced scanning at 6 h, 12 h, 24 h and 48 h after injection , and P-Gd-probe was as the enhanced contrast agent.The signal noise ratio ( SNR) of the pancreas were measured before and after enhancement .Then the pancreas tissues were harvested for pathological examination and P selectin expression in pancreatic tissue was detected using immunohistochemical analysis .Results Inflammation was observed in pancreatic tissue at 6h after establishment , and became more serious as the modeling time extended .P selectin expression was increased as pancreatitis inflammation became more serious .The SNR of control group was stable before and after enhancement.The SNR before and after enhancement was 17.22 ±1.35 and 37.38 ±1.66 in AEP group, and 16.29 ±1.39 and 58.18 ±1.03 in ANP group.The SNR after enhancement was higher than that before enhancement, and the differences were significantly different ( t=-49.59 and -86.09, P<0.001 ). Conclusions Monoclonal antibody MRI contrast agent targeting P selectin is helpful in evaluating the severity of AP.
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Objective To explore the value of Multiple b value DWI ( MbDWI ) in the short-term efficacy evaluation of cyberknife radiotherapy for locally advanced pancreatic cancer ( LAPC ) .Methods A total of 36 patients underwent both conventional sequence and respiratory triggered MbDWI ( b=0, 25, 50, 75, 100, 150, 200, 400, 600, 800, 1 000 s/mm2 ) before cyberknife radiotherapy, 1month and 3 months after the radiotherapy, respectively.ADCtot, f, Dfast and Dslow were calculated using single and double exponential model and the changes before and after radiotherapy were observed.Results Before radiotherapy, 1 month and 3 months after radiotherapy, the ADCtot values of solid lesions were (1.56 ±0.29) ×10-3 mm2/s, (1.75 ±0.31) ×10 -3 mm2/s and (18.6 ± 0.46) ×10 -3 mm2/s;the values of Dslow were (1.10 ±0.73) × 10 -3 mm2/s, ( 1.19 ±0.97 ) ×10 -3 mm2/s and ( 1.49 ±04.6 ) ×10 -3 mm2 s/; the values of Dfast were (83 .33 ±62 .57) ×10 -3 mm2/s,(124.57 ±123.10) ×10 -3 mm2/s and (108.07 ±96 .67) ×10 -3 mm2 /s; f values were (26.81 ±23.74)%,(23.61 ±22.75)% and (21.34 ±15.36)%, respectively.ADCtot values 1 month and 3 months after treatment were significantly higher than those before treatment and Dslow 3 months post-treatment was higher than that before treatment, and the differences were statistically significant ( both P<0.05) and no other differences between two groups were significant.There were no statistical differences on Dfast and f before and after radiotherapy.Conc lusions ADCtot and Dslow both showed a significant growth trend after cyberknife radiotherapy.The advanced degree of parenchymal cystic in the targeted lesion could reflect the short-term efficacy of cyberknife treatment.
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Objective To study the potential and value of ultrasmall superparamagnetic iron oxide (USPIO) conjugated by mesothelin antibody as MRI targeting contrast agent for diagnosis of implanted human pancreatic carcinomas in nude mouse.Methods Nude mouse tumor models bearing multiple human pancreatic carcinomas at different time points was established and they were randomized into two groups,and USPIO or MSLN-USPIO were used as contrast enhanced agents in the 3.0T MRI scan,respectively,then the positive detection rates for smallest tumors,and the signal intensity of tumors in T2 mapping images of both unenhanced and contrast enhanced scanning and the negative enhancement rate were measured,then Prussian blue staining was performed in alI the tumor specimens to observe the difference of Fe3 + ion deposition.Results There was no statistical significance between USPIO group and MSLN-USPIO group in the positive detection rates for smallest tumors.In USPIO group,the negative enhancement rate of left or right axilla tumors was (12.29 ±7.45)％ and (11.06 ±5.91)％,and they were (33.88 ±6.09)％ and (43.29 ± 11.64)％ in MSLN-USPIO group.There was statistical significance in the difference of signal intensity between unenhanced and contrast enhanced in left or right axilla tumors (P ＜ 0.05),and the negative enhancement rate in MSLN-USPIO group was significantly higher than that in USPIO group (P ＜0.05).The Fe3+ ion deposition in tumors' tissue in MSLN-USPIO group was significantly more than that in USPIO group.Conclusions The enhanced effect of MSLN-USPIO is superior to USOPIO,and it can be a tumor targeted MR contrast enhanced agent for the diagnosis of pancreatic carcinoma in nude mouse.
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Objective To investigate effect of secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) on visualization improvement of main and branch pancreatic duct and its diagnostic value of grading chronic pancreatitis (CP) .Methods The 3 .0 T magnetic resonance (MR) imaging data of 88 subjects (23 health volunteers and 65 CP patients) were prospectively analyzed .All the subjects received coronal T2-weighted sequences scan ,thick slab 2-dimensional MRCP sequences scan , routine pancreas plain scan and enhanced scan before and after 0 .1 mL/kg secretin intravenous injection . Sixty-five CP patients were grouped according to Cambridge classification and also according to normal and abnormal of duodenal filling (DF) .The images of main pancreatic duct (MPD) ,branch pancreatic duct (BPD) and DF were compared before and after secretin injection .The result was compared with that of endoscopic retrograde cholangio pancreatography (ERCP) which was the gold standard .One-way analysis of variance test was performed for comparison between healthy control group and CP group .Chi-square test was used for comparison between normal DF group and abnormal DF group .The consistence between the diagnostic results of MRCP ,S-MRCP and the results of ERCP were analyzed by Kappa test .Results Compare with MRCP ,after secretin injection the indexes of MPD ,the sensitivity ,specificity ,positive predictive value and negative predictive value of BPD were all improved ,and the rates of misdiagnosis and missed diagnosis all decreased .Using ERCP as gold standard of CP grade diagnosis ,the consistence of S-MRCP in CP grade diagnosis increased more significantly (Kappa=0 .77 ,P=0 .000 1) compared with that of MRCP (Kappa=0 .55 ,P=0 .000 1) .Among 43 normal DF cases ,the number of MPD dilatation , filling defect and branch duct in pancreatic head was 28 ,23 and 30 ,respectively ;among 22 abnormal DF cases which was 20 ,19 and 21 ,respectively ,and the differences were statistically significant (χ2=5 .01 , 3 .91 ,6 .88 and 4 .26 ,all P<0 .05) .Taking 4 min as the cutoff value of peak time ,the sensitivity and specificity of which in CP diagnosis were 86 .0% and 100 .0% , respectively . Conclusion S-MRCP improves the visualization of MPD and BPD ,and also increases the accuracy of CP grade diagnosis .
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Objective To describe the imaging findings of pancreatic and extra-pancreatic lesions of autoimmune pancreatitis (AIP),to improve the imaging diagnostic accuracy of AIP.Methods From 2011 to June 2014,38 AIP patients according to 2010 international consensus diagnostic criteria for AIP were included.Thirty-six patients underwent contrast enhanced CT scan,17 patients underwent contrast enhanced MRI,15 underwent MRCP,and the imaging data were retrospectively reviewed.Results In the 38 patients,the pancreas showed diffuse enlargement in 23,focal enlargement in 9,mixed enlargement in 6.All the patients demonstrated as progressive enhancement and gradually delayed enhancement.Fourteen cases showed diffusely irregular narrowing of the main pancreatic duct.Pseudo-capsule like structure was presented around the lesions in 24 cases.Extra pancreatic lesions included biliary duct involvement in 24 cases,renal lesions in 4 cases,peri-pancreas vessels involvement in 20 cases,8 cases with enlargement of lymph nodes.Conclusions AIP presents with characteristic imaging features in pancreas and extra pancreatic organs.Imaging tests are helpful in the early diagnosis of AIP.
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Objective To investigate the feasibility of the arterial wall imaging technology of high-resolution magnetic resonance imaging ( HR-MRI) in the risk assessment of intracranial aneurysm rupture. Methods Fifty-four patients with 66 intracranial aneurysms underwent 3. 0 T HR-MRI multiple sequences arterial wall imaging from November 2013 to March 2015 were analyzed retrospectively. Five patients with ruptured aneurysm were used as a control group. The characteristic differences of aneurysm lesions between an unruptured intracranial aneurysm ( UIA) wall enhancement group and a non-enhancement group were compared. The risk factors for rupture were analyzed according to the size,location, and basic clinical characteristics of aneurysm. Results (1) HR-MRI revealed that whether the aneurysm walls enhanced or not,there were no significant differences in the location size,wide-necked aneurysm or not,and ratios of aneurysm height and neck width (all P >0. 05). (2) The enhancement rates of the aneurysm volume <2 group and ≥2 group were 20%(8/40) and 61. 9%(13/21) respectively,the incidence of the ruptured aneurysm asci was higher than that of UIA,and there was significant difference ( all P<0. 05). There were no significant differences in neck width,rate of aneurysm volume,ratios of aneurysm height and neck width,and enhancement rates among the groups. Conclusion The preliminary results of this study have showed that there is a related trend between the HR-MRI aneurysm wall enhancement and the risk of rupture,but a further large sample follow-up study is needed.
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Objective To discuss the value of combining secretin-enhanced MR cholangiopancreatography (MRCP) and conventional MRI in the evaluation of chronic pancreatitis (CP).Methods Seventeen normal volunteers,and 36 patients with CP were enrolled in this study.Thick slab two dimension MRCP sequence,coronal T2 weighted sequence and conventional MRI were performed on all subjects.The changes of pancreatic ducts were observed before and after the injection of secretin.The exocrine function of the pancreas was evaluated using duodenal filling (DF) grades.Pancreatic parenchyma was reflected by signal intensity ratio (SIR) between the pancreas and the left psoas muscle on MR plain scan,and the ratio between the pancreatic substance phase and portal phase (A/V) of MR enhanced scan.All subjects were classified based on Cambridge classification and DF grades.The SIR and A/V were compared between all groups of Cambridge classification using the one-way ANOVA test,and between two groups of DF grades using Student's t test.Correlations between Cambridge classifications,DF grades and SIR,A/V were tested using Spearman rank correlation coefficients.Results After secretin injection,the visualization of all portions of the main pancreatic ducts and branch ducts were significantly improved in all subjects.Ten minutes after secretin injection,17 volunteers showed grade 3.Grade 3,2 and 1 were seen in 23,8,5 patients,respectively.Mild,moderate and severe CP by Cambridge classification showed in 11,12,13 patients,respectively.The mean SIR values of the volunteers and the three groups were 1.21 ± 0.19,1.07 ±0.21,0.98 ± 0.21 and 0.85 ± 0.18,respectively; the mean A/V values:1.15 ± 0.11,1.23 ± 0.34,0.97 ± 0.16 and 0.91 ± 0.12.There was statistically significant difference of SIR and A/V (F =8.72 and 7.72,P ＜0.01) between volunteers and CP.Normal and abnormal DF were seen in 40 and 13 patients.The mean SIR values of the two groups were 1.09 ± 0.20 and 0.88 ± 0.27 ; the mean A/V values:1.15 ± 0.11 and 0.94 ± 0.30.There was statistically significant difference of SIR and A/V (t =3.10 and -2.40,P ＜ 0.01) between two groups.There were correlations between Cambridge classification,DF grades and SIR (r =0.60 and 0.41,P＜0.01),A/V (r =0.60 and 0.52,P＜0.01).Conclusion Secretin-enhanced MRCP combined with conventional MRI can be used to evaluate CP regarding changes of morphology and function,which can provide a useful reference for the clinical diagnosis.
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Objective To investigate and determine the apparent diffusion coefficient (ADC) values in different anatomical regions of normal pancreas.Methods A total of 383 volunteers with normal pancreas were included in this study.Single-shot echo planar imaging diffusion weighted imaging (SSEP-DWI; b value =0,500 s/mm2) was employed to determine the ADCs in the head,neck,body and tail parts of the pancreas.Statistical analysis was performed by using Kruskal-Wallis and Wilcoxon signed rank tests.Results The ADCs in the head,neck,body and tail parts of the pancreas was (1.52 ± 0.29) × 10-3,( 1.64 ± 0.34) ×10-3,(1.67±0.35) × 10-3,(1.58 ±0.31) × 10-3 mm2/s,the Kruskal-Wallis test results showed a significant difference of mean ADCs among the different anatomical regions (chi square =44.8748,P ＜0.0001 ).Wilcoxon signed rank test results showed the mean ADCs differed remarkably between the head and neck ( P ＜ 0.0001 ),head and body ( P ＜ 0.0001 ),head and tail ( P =0.0008 ),neck and tail (P =0.0062 ),body and tail (P ＜0.0001),respectively.The mean ADCs between the neck and body was not significantly different (P =0.1181 ).Conclusions The mean ADC values of normal pancreas vary significantly within different anatomical regions,which can serve as a guide for DW1 and ADC in clinical application and research of pancreatic diseases.
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Objective To compare the mesothelin expressions in 3 human pancreatic cancer cell lines between in vitro and in vivo and the developing speed among the subcutaneous tumors implanted with the 3 human pancreatic cancer cell lines in nude mice.Methods The human pancreatic cancer cell lines ( SW1990,BxPC3 and PANC1 ) were cultured and then were implanted subcutaneously into left axillas of nude mice.The volumes of these subcutaneous tumors were recorded every week to estimate their developing speed.The mice implanted with SW1990 and BxPC3 cells were observed for three weeks,while the mice implanted with PANC1 cell were observed for five weeks.The Western blot method was used to measure the expressions of mesothelin in the 3 kinds of cells and subcutaneous tumors,while immunohistochemical staining was applied to determine the expressions of mesothelin in 3 kinds of subcutaneous tumors.Results The sequence of quantities of expressions of mesothelin in these cell lines in vitro were BxPC3 ＞ PANC1 ＞ SW1990,and the sequence of quantities of expressions in vivo were SW1990 ＞ BxPC3 ＞ PANC1.One handrued percent of the tumors grew out successfully,and the sequence of speeds of their growth was SW1990 ＞ BxPC3 ＞ PANC1.Conclusions The mesothelin expressions among 3 kinds of pancreatic cancer cell line are different.The developing speeds of tumors originated from different subcutaneous tumors in nude mice are also different,and there is no association between them.
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ObjectiveTo study the water/fat ratio of patients with pancreatic ductal adenocarcinoma (PDAC) and mass-forming focal chronic pancreatitis (MFP),and to provided guide for the clinicians.MethodsThirteen patients with PDAC,8 patients with MFP and 20 healthy volunteers were scanned by GE 3.0T MR IDEAL sequence.The signal strength of outcome images was measured; the water/fat ratio analysis was performed.Two kinds of formula were applied,the first was WF1 =SW/SF,the second was WF2 =( SIP + SOP) / ( SIP - SOP).SW was the signal strength of water,SF was the signal strength of fat,and SIP was the signal strength of in-phase,while SOP was the signal strength of opposite phase.ResultsBy using the WF1 formula,the water/fat ratio of normal pancreas,PDAC,MFP was 7.97 ±0.95,9.94 ±1.19,5.08 ±0.49,respectively.By using the WF2 formula,the water/fat ratio of normal pancreas,PDAC,MFP was 11.51 ± 1.62,13.87 ±1.84,5.73 ±0.65,respectively.The difference among the three groups was statistically significant (P ＜ 0.05 ) under the same formula.The value of WF2 was higher than that of WF1,the difference in PDAC groups was also statistically significant ( P ＜0.05 ).ConclusionsThe water/fat ratio of pancreas among PDAC,MFP and normal pancreas is different.PDAC has the highest water/fat ratio,followed by the normal pancreas; MFP has the lowest ratio.
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Objective To investigate the feasibility of pancreatic DWI at a 3T MR imager and its value for the qualitative diagnosis of pancreatic tumors. Methods For 20 normal healthy volunteers and 47 patients with pancreatic tumors [21 pancreatic carcinoma (PC), 7 mass-forming chronic pancreatitis (MFCP)and 19 cystic lesions), routine pancreatic MRI and pancreatic DWI using b values (500 and 1000 mm2/s)were obtained, the DWI signal intensity (SI) and apparent diffusion coefficient (ADC) value of pancreatic lesions and adjacent tissue was measured. Results In the b = 500 and 1000 mm2/s DWI images, there was no significant difference in ADC value between different parts of normal pancreas. But PC and MFCP were shown as hyperintensity mass, in addition, the related SI1000 of PC at b = 1000 mm2/s DWI was significantly higher than that of MFCP (1.238 +0.448 vs. 0.371 +0.293, P＜0. 01). Compared with normal pancreas,beth PC and MFCP presented as decreased ADC500 and ADC1000 value. The ADC1000 of PC was significantly lower than that of MFCP [ ( 1. 087 + 0. 175 ) mm2/s vs. ( 1. 279 ± 0.213 ) mm2/s]. Pancreatic cystic lesions were shown as hyperintensity in DWI at b = 500 mm2/s, but were depicted as iso-intense signal or low-signal lesions in DWI using b = 1000 mm2/s. Both ADC500 and ADC1000 of pancreatic cystic lesions were higher than that of normal pancreas. Conclusions 3T-MR DWI is helpful to differentiate pancreatic lesions. High b value DWI is more valuable for the qualitative diagnosis of pancreatic mass.