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Objective To evaluate the value of texture features derived from intravoxel incoherent motion (IVIM) parameters for differentiating pancreatic neuroendocrine tumor (pNET) from pancreatic adenocarcinoma (PAC).Methods Eighteen patients with pNET and 32 patients with PAC were retrospectively enrolled in this study. All patients underwent diffusion-weighted imaging with 10 b values used (from 0 to 800 s/mm ). Based on IVIM model, perfusion-related parameters including perfusion fraction (f), fast component of diffusion (D) and true diffusion parameter slow component of diffusion (D) were calculated on a voxel-by-voxel basis and reorganized into gray-encoded parametric maps. The mean value of each IVIM parameter and texture features [Angular Second Moment (ASM), Inverse Difference Moment (IDM), Correlation, Contrast and Entropy] values of IVIM parameters were measured. Independent sample t-test or Mann-Whitney U test were performed for the between-group comparison of quantitative data. Regression model was established by using binary logistic regression analysis, and receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic efficiency.Results The mean f value of the pNET group were significantly higher than that of the PAC group (27.0% vs. 19.0%, P = 0.001), while the mean values of D and D showed no significant differences between the two groups. All texture features (ASM, IDM, Correlation, Contrast and Entropy) of each IVIM parameter showed significant differences between the pNET and PAC groups (P=0.000-0.043). Binary logistic regression analysis showed that texture ASM of D and texture Correlation of D were considered as the specific imaging variables for the differential diagnosis of pNET and PAC. ROC analysis revealed that multiple texture features presented better diagnostic performance than IVIM parameters (AUC 0.849-0.899 vs. 0.526-0.776), and texture ASM of D combined with Correlation of D in the model of logistic regression had largest area under ROC curve for distinguishing pNET from PAC (AUC 0.934, cutoff 0.378, sensitivity 0.889, specificity 0.854).Conclusions Texture analysis of IVIM parameters could be an effective and noninvasive tool to differentiate pNET from PAC.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Adenocarcinoma , Diagnostic Imaging , Algorithms , Diagnosis, Differential , Diffusion Magnetic Resonance Imaging , Motion , Pancreatic Neoplasms , Diagnostic Imaging , Retrospective StudiesABSTRACT
Objective To analyze the clinical and magnetic resonance imaging(MRI)findings of solid pseudopapillary tumor(SPT)of the pancreas in male patients. Methods Clinical and MRI features of 51 patients with pathologically-proved SPT were retrospectively analyzed.The following MRI features of the lesions were analyzed:location,maximal diameter,shape,margin,capsule,solid and cystic components,signal intensity characteristics,and enhancement patterns.Results The average maximal diameter of the SPT in male patients was significantly smaller [(3.9±1.6)cm vs.(6.3±3.9)cm,P=0.035]than that of SPT in female patients.Pure solid tumors were signiciantly more common in male patients(8/14)than in female patients(9/37)(P=0.037).T-weighted images of SPT showed mainly homogenous hypo-intensity in male patients(11/14)and heterogeneous hypo-intensity in female patients(23/37)(P=0.001).Hemorrhage was more prevalent in female patients(22/37)than in male patients(2/14)(P=0.005).There were no significant differences between male and female patients regarding clinical features and other magnetic resonance features(P>0.05).Conclusions On MRI,SPT in male patients is small and shows mainly pure solid component with rare hemorrhage.The clinical and other MRI features of SPT are not different between males and females.
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<p><b>BACKGROUND</b>Coronal diffusion-weighted magnetic resonance imaging (DW-MRI) and apparent diffusion coefficient (ADC) values have gradually become applied (following conventional axial DW-MRI) in the renal analysis. To explore whether data obtained using coronal DW-MRI are comparable with those derived using axial DW-MRI, this preliminary study sought to assess the agreement in renal ADC values between coronal DW-MRI and axial DW-MRI.</p><p><b>METHODS</b>Thirty-four healthy volunteers were enrolled in the study; written consents were obtained. All subjects underwent respiratory-triggered axial and coronal DW-MRI using a 1.5-MR system with b values of 0 and 800 s/mm 2 . The signal-to-noise ratios (SNRs) of the two DW-MRI sequences were measured and statistically compared using the paired t-test. The extent of agreement of ADC values of the upper pole, mid-pole, and lower pole of the kidney; the mean ADC values of the left kidney and right kidney; and the mean ADC values of the bilateral kidneys were evaluated via calculation of intraclass correlation coefficients (ICCs) or Bland-Altman method between the two DW-MRI sequences.</p><p><b>RESULTS</b>The SNR of coronal DW-MR images was statistically inferior to that of axial DW-MR images (P < 0.001). The ICCs of the ADC values of each region of interest, and the mean ADC values of bilateral kidneys, between the two sequences, were greater than 0.5, and the mean ADCs of the bilateral kidneys demonstrated the highest ICC (0.869; 95% confidence interval: 0.739-0.935). In addition, 94.1% (32/34), 94.1% (32/34), and 97.1% (31/34) of the ADC bias was inside the limits of agreement in terms of the mean ADC values of the left kidneys, right kidneys, and bilateral kidneys when coronal and axial DWI-MRI were compared.</p><p><b>CONCLUSIONS</b>ADC values derived using coronal DW-MRI exhibited moderate-to-good agreement to those of axial DW-MRI, rendering the former an additional useful DW-MRI method, and causing the ADC values derived using the two types of DW-MRI to be comparable.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Diffusion Magnetic Resonance Imaging , Methods , Healthy Volunteers , Image Interpretation, Computer-Assisted , Methods , Kidney , Magnetic Resonance Imaging , MethodsABSTRACT
<p><b>OBJECTIVE</b>To compare the adjustable oblique position with prone position in microendoscopic discectomy (MED) and to evaluate its advantages.</p><p><b>METHODS</b>One hundred and twenty-eight patients who underwent MED during August 2000 and August 2002 were studied. Forty-seven cases were positioned prone, 81 cases were positioned with adjustable oblique position. Operating time, blood loss and patient endurance were recorded and compared. The airway resistance of 29 lumbar disorder patients was measured when they were positioned supine, lateral and prone respectively after general anesthesia.</p><p><b>RESULTS</b>There was statistically significant difference between 2 groups in operating time, blood loss and endurance. In prone position group, when operating time lasted for more than 50 min, 75% patients felt hurt on the skin of rib arch, and 38% patients presented dizzy and nausea. And all the patients had erythema on the rib arch. In the adjustable oblique position group, 3 cases had shoulder pain after operation, and 1 case had 4 days' common poroneal nerve paralysis. The airway resistance of patients with prone position was significantly higher than those with supine and lateral positioned patients. (P < 0.05).</p><p><b>CONCLUSION</b>The adjustable oblique position in MED had the following advantages: (1) Do not limit the movement of chest and help reduce intra-abdominal pressure and epidural bleeding; (2) Give the lumbar spine the largest degree of flexion and the largest interlaminar space, which prevents injury of facet joint; (3) Increase posterior intervertebral space and make disectomy easier and exposure of nerve root and nerve root canal clearer; (4) The patients feel comfortable and can adjust the position of lumbar spine and lower extremity; (5) The monitor has the same direction with doctor, and it is easy for the doctor to operate; (6) Doctor can sit during operation.</p>
Subject(s)
Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Diskectomy , Methods , Intervertebral Disc Displacement , General Surgery , Lumbar Vertebrae , General Surgery , Microsurgery , Methods , Posture , Prone Position , Treatment OutcomeABSTRACT
<p><b>OBJECTIVE</b>To identify and clone the gene named pfstom gene which encoding the protein belonging to band 7 family and to do primary research on its function.</p><p><b>METHODS</b>Based on the finished data in international public malaria database, coding sequence of pfstom cDNA was obtained by RT-PCR from FCC1/HN. Its phylogenetic profiles and the homogeny were analyzed by some softwares. After Prokaryotic expression, C terminal of Pfstom protein was expressed by Pet30a system. Recombinant Pfstom protein was used to immol/Lunize rabbit and then serum was harvested and the IgG was purified for Western blot.</p><p><b>RESULTS</b>The coding sequence of pfstom is 1,125 bp which encoding 374 amino acids with C-terminal fragment being homogenous to stomatin-like protein which belongs to band 7 family. Phylogenetic profiles analysis revealed its homogeny to stomatin. Western blot showed its stage-specific expression in trophozoite.</p><p><b>CONCLUSION</b>Pfstom belongs to band-7 family. It was expressed specifically in trophozoite in erythrocyte stage of plasmodium falciparum. It was not expressed in ring stage. And it is membrane-related protein. All these results provided the foundation for further research on pfstom.</p>