Objective To evaluate the accuracy of fatsuppressed fast spoiled gradient echo(FSPGR) T_1WI in detection of pancreaticdisease using the receiver operating characteristic curve(ROC).Methods The pancreas were evaluated in 92 subject investigated(57normal and 35 with pancreatic disease) with fat saturation FSPGR T_1WI.The signal intensity(SI) ratio of pancreas relative to liver and spleen was quantitatively measured using regions of interest(ROIs),then qualitatively assessed by one independent observers.Results The mean values of pancreas-liver ratios and pancreas-spleen ratios between a normal and an abnormal pancreas were significantlydifferent.Thearea under ROC curve of the pancreas-liver SI ratio and the pancreas-spleen SI ratio was 0.92?0.03 and 0.91?0.04,respectively.There was no statistically significant difference between quantitative and qualitative analysis for the diagnosis of pancreatic disease when using liver as comparable standard.The sensitivity of qualitative pancreas in comparison with liver was 86.7%,while specificity was 91.2%.Conclusion When the SI ratio of pancreas-liver is used to distinguish normal from abnormal pancreas,qualitative analysis by observers is as accuracy as quantitative measurement.

Objective To explore diagnostic value of MR perfusion weighted imaging(PWI)on complications and tumor recurrence in hypopharyngeal and laryngeal cancer after operation and radiotherapy. Methods MR PWI was performed in 31 patients with hypopharyngeal and laryngeal cancer who suffer from tumor recurrence, granulation or infection after operation and radiotherapy. Blood flow (BF), blood volume(BV), mean transit time(MTT) and time to peak (TTP) values were measured in the lesions. Analysis of variance and pair-wise comparison of q test were used for statistical analysis. Results Eleven cases with tumor recurrence,11 case with granulation tissues, 9 cases with infection were confirmed by pathological examinations. Average BF, BV, MTT and TTP values of recurrent tumors were (145.1 ± 29.3)ml · 100 g-1 · min-1,(14.2 ± 3.2)ml · 100 g-1,(5.4 ± 0.6)s,(13.7 ± 1.3)s respectively;Average BF, BV MTT and TTP values of granulation tissues were(109.1±27.4)ml·100 g-1·min-1,(11.1±1.7)ml·100 g-1,(7.7±1.0)s, (19.8 ± 2.1)s respectively;Average BF, BV, MTT and TTP values of infectious tissues were(86.9 ± 7.7)ml · 100 g-1·min-1,(8.8±1.0)ml·100 g-1,(8.0±0.9)s,(19.7±1.3)s respectively. Average BF and BV values of the recurrent tumors group were higher than those of the granulation(q=4.89, 4.64 respectively,P<0.01)and infection group(q=7.52,7.71 respectively,P<0.01)respectively. Average BV values of granulation group was higher than that of the infection group(q=3.31,P<0.05), Average MTT and TTP values of recurrent tumor group were lower than those of the granulation (q=9.38, 12.48 respectively,P<0.01)and infection group(q=9.77, 11.53 respectively,P<0.05). There were no significant difference in average BF, MTT and TTP between the granulation and infection group. Conclusion MR PWI can be helpful in the diagnosis of complications and tumor recurrence in hypopharyngeal and laryngeal cancer after operation and radiotherapy.

ObjectiveTo investigate the value of diffusion tensor imaging (DTI) at high b value for unilateral middle cerebral artery (MCA) occlusive disease in patients without obvious infarct lesions on conventional MR imaging.MethodsDTI at high b value (2200 s/mm2 ) was performed using a 3.0 Tesla MR scanner in 34 patients with unilateral middle cerebral artery occlusion,who had no obvious infarct lesions on conventional MR imaging. Fractional anisotropy (FA),apparent diffusion coefficient (ADC),axial diffusivity (eigenvalue λ1) and radial diffusivity (eigenvalues λ2,λ3) were measured at the ipsilateral and contralateral corona radiata,anterior and posterior limbs of the internal capsule,cerebral peduncle and pons in all subjects.Mean ADC,FA,λ1,λ2 and λ3 values of corona radiata,anterior and posterior limbs of the internal capsule,cerebral peduncle and pons were compared between the ipsilateral and contralateral MCAterritory by t test. Results Among the 34 patients,left MCA occlusion in M1 segment occurred in 16 patients and right MCA occlusion in Ml segment occurred in 18 patients.At the ipsilateral corona radiata,mean FA,ADC,λ1,λ2 and λ3 were 0.419 ±0.032,(5.975 ±0.272) × 10 3,(5.704 ±0.365) ×10-3,(6.412 ±0.368) × 10-3 and (6.605 ±0.343) × 10-3 mm2/s,respectively.At the contralateral corona radiata,mean FA,ADC,λ1,λ2 and λ3 were 0.443 ± 0.033,(5.804 ± 0.282) × 10 -3,(5.651 ±0.350) × 10-3,(6.099 ±0.353) × 10-3 and(6.372 ±0.355) × 10-3 mm2/s,respectively.At the ipsilateral corona radiata,mean FA was significantly decreased(t =11.614,P ＜0.01),and mean ADC (t=12.421,P＜0.01),λ1(t =7.447,P＜0.01),λ2(t=10.244,P＜0.01) and λ3(t=9.890,P＜0.01) were significantly increased.At the ipsilateral anterior and posterior limb of the internal capsule,mean FA were 0.609 ±0.026 and 0.674 ±0.033,λ1 were(5.330 ±0.462) × 10 -3 and(5.171 ±0.456) ×10-3 mm2/s,respectively.At the contralateral anterior and posterior limb of the internal capsule,FA were 0.622 ±0.026 and 0.694 ±0.034,λ1 were(5.064 ± 0.448) × 10 -3 and(4.924 ± 0.365) × 10 -3 mm2/s,respectively.Mean FA was significantly decreased (t =7.823,8.013,all P ＜ 0.01) and mean λ1 was significantly increased (t =7.811,8.800,all P ＜0.01) at the ipsilateral anterior and posterior limbs of the internal capsule.There was no significant difference in ADC,λ2 and λ3 value between the ipsilateral and contralateral sides.And all the DTI parameters,including mean ADC,FA,λ1,λ2 and λ3 values,showed no statistical difference between both sides of cerebral peduncle and pons.ConclusionDTI at high b valuc can provide useful information for visualizing ischemic white matter injury in patients without obvious infarct lesions on conventional MR imaging.

Objective To investigate the MRI features of different fibrotic stroma of hepatocellular carcinomas (HCC) and the relationships between them and delayed contrast-enhanced MR findings. Methods Twenty eight patients were enrolled in the study who had undergone dynamic contrast-enhanced MRI scanning. MRI showed largely complete rim-like enhancement in delayed phase in all the lesions which were confirmed by surgery and pathology. Delayed-enhancement in peripheral and internal position of HCC were evaluated and the thicknesses of rim-like enhancement in delayed phase were measured by analyzing the 5 minute delayed images. Among the 28 lesions, 22 were sampled and pathologically analyzed both in peripheral and internal portion of HCC and the remaining 6 were in the internal portion only. The pathological features were observed including distributions of three fibers (elastic, collagen and reticular fibers) in the periphery and internal positions of HCC, degrees of inflammatory cells infiltration outside the capsule and in the internal portion of HCC, the blood vessels in the capsules and thicknesses of fibrous capsule. The pathological features of HCC with different degrees of delayed-enhancement were compared using χ2 test, and differences in the thicknesses of rim-like enhancement of HCC in delayed phase among different pathological features were analyzed using Chi-square test. Results (1) In the periphery:pathological features: the typical fibrous capsules showed in all 22 HCC. And three kinds of fibers were crisscrossed within the capsules without quantitative differences. MRI findings:statistical differences in the amounts of blood vessels in the capsule of HCC among different degrees of delayed-enhancement were found (P<0.05), however, the differences in the thicknesses of fibrous capsule and the degrees of inflammatory cells infiltration were not found (all P>0.05). In addition, the statistical differences in the thicknesses of rim-like enhancement of HCC showed among different thicknesses of fibrous capsule, degrees of inflammatory cells infiltration and amounts of blood vessels (all P<0.05). (2) In the internal positions:pathological features: the amounts of three kinds of fibers in the internal positions were significantly lower than those in the periphery. MRI findings: the statistical differences in collagen fibers, elastic fibers, reticular fibers and the degrees of infiltration of inflammatory cells of HCC were all seen among different degrees of delayed enhancement inside tumors (all P<0.05). Conclusion The delayed MR enhancement of HCC in peripheral and internal positions showed correlation with the fibers and degrees of infiltration of inflammatory cells in the tumor.

Objective:To evaluate the accuracy and ch aracteristics of combined use of 99Tcm-sulfur colloid (SC)and 9 9Tcm-diethyliminodiacetic acid (EHIDA)imaging on the diagnosis of hepat ic adenoma (HA). Methods:8 patients with HA were involved in this study.All of them were studied by nuclear medicine (NM)with dual-radiopharmaceuticals.The 99 Tcm-SC imaging was perfomed first ,then the 99Tcm-EHIDA im aging two days later,and the ratios between lesions and normal liver tissue(L/N) were calculated in terms of different counts within the same size regions of int erest (ROI) in different phases(30min,1h and 2h respectively).Some of the cases were also analysed by CT and/or MRI within one week before the operations. Results:All of the cases were submitted to surgical treatment and c onfirmed diagnosis of HA by pathology. For HA, scintigrahy presented a accuracy of 100%(8/8),which was higher than that of CT and MRI comparatively.For 99 Tcm-EHIDA imaging,there were significant differences in L/N ratios among different phases(30min,1h and 2h). Conclusion:The results show that radionuclide imaging proved to be a safe,invasive and effcetive method on the diagnosis and differential diagnosis of HA,especially ,when CT and/or MRI findings are not typical.

Objective: To study the different ischemic characteristics of cerebral gray matter and deep white matter in patients with chronic cerebral artery severe stenosis or occlusion. Methods: A retrospective study was conducted on 30 patients with chronic unilateral cerebral artery severe stenosis or occlusion from April 2014 to April 2018 in our hospital. Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time of peak time (TTP) and time to delay(TTD) of cerebral cortex gray matter and deep white matter in the blood supply area of the responsible artery (the affected side) and the contralateral hemisphere (the healthy side) were measured. Statistical analysis of the perfusion parameters of cerebral cortex gray matter and deep white matter in the affected side and contralateral side were performed using SPSS13.0 software package. T test was used for variance homogeneity, and t′ test was used for variance discrepancy, and P<0.05 was statistically significant. Results: The average values of CBF and CBV of the ipsilateral and contralateral cerebral cortex were increased than those of ipsilateral and contralateral cerebral deep white matter respectively(P<0.01). MTT, TTP and TTD of the ipsilateral and contralateral cerebral cortex were decreased than that of ipsilateral and contralateral cerebral deep white matter (P<0.01); CBF of ipsilateral cerebral cortex and CBV of ipsilateral cerebral deep white matter were not different from those of the contralateral cerebral cortex and deep white matter respectively, but CBF of ipsilateral cerebral deep white matter is decreased than that of the contralateral deep white matter (P<0.01). CBV of ipsilateral cerebral cortex is increased than that of the contralateral cerebral cortex (P<0.01). MTT, TTP and TTD of ipsilateral cerebral cortex and deep white matter were increased than those of contralateral cerebral cortex and deep white matter respectively(P<0.01). Conclusion Deep cerebral white matter perfusion decreased more significantly than cortical gray matter in the supply region of chronic cerebral artery severe stenosis or occlusion. CT perfusion imaging can quantify the degree of chronic cerebral ischemia and can provide quantitative diagnostic information for clinical treatment and efficacy evaluation.

Objective To investigate the imaging features of the cerebral complications of infective endocarditis (IE)and the evolution process of infective cerebral infarction.Methods The clinical and imaging data from 5 patients diagnosed as IE with neurological complications were retrospectively and comprehensively reviewed,so that the imaging features of cerebral complications and infective cerebral infarctions were summarized.Results Among the 5 cases,3 showed multiple acute infarctions,including 2 massive ones.All the 5 cases showed multiple hemorrhagic lesions at different stages.The infarction and hemorrhage were mostly located at the corticalGmedullary junction.1 case of subarachnoid hemorrhage and 1 case of meningitis were also observed.Two massive infarctions mentioned above showed irregular patchy shape,which evolved into cerebral abscesses after 1 2 and 1 5 days of neurological symptoms showing up,then abscesses started shrinking after 33 and 3 1 days,respectively.Conclusion MRI can accurately reflect the features of cerebral complications of IE and the evolution process of infective cerebral infarctions,which provides evidences for physicians to make correct diagnoses and the treatment plans.

Objective To discuss the hemodynamic features of internal carotid aneurysm,and study the relationship between hemodynamics and occurrence,development and rupture of internal carotid aneurysm .Methods The 3D model of internal carotid aneurysm was established by materialise's interactive medical image control system(MIMICS).The finite element analysis software ANSYS was used to carry out numerical simulation.Results Low wall shear stress of internal carotid aneurysms were located at the same area.The wall shear stress at different region were positive correlation with the blood flow velocity.Conclusion The blood flow velocity and wall shear stress at the top of aneurysm are relatively low.This position is consistent with the rupture position.The significant changes of hemodynamic at the top of aneurysm may trigger a series of mechanical biological effects on the internal carotid aneurysm wall.The changes alters cells'gene and protein's expression,causes rupture of the aneurysm.

Objective To analyze the clinical,radiological features and risk factors of diplopia in patients with acute lacunar infarction (ALI).Methods Retrospectively retrieved patients of ALI (lesion diameter was less than 1.5 cm in DWI sequence)diagnosed by MR and clinical.We further summarized 13 ALI patients with diplopia and randomly selected 13 ALI patients without diplopia as the control group. SPSS22.0 statistical software was used for statistical analysis.The general clinical data such as sex and age was compared by Ch-i square test and t-test.The risk factors were primarily analyzed by one-way ANOVA and then the risk factors with statistical significance were brought into the logistic regression model for multivariate analysis.Results The incidence of diplopia in ALI patients was about 2.7%(13/489). The infarct sites were all located in the brain stem of the oculomotor-related brain nucleus and the dorsolateral medulla oblongata.Hypertension and hematocrit were negatively correlated with diplopia after infarction (P＜0.05 ).Conclusion The incidence of diplopia is low in ALI patients.The medial longitudinal tract of the dorsolateral medulla is an important area causing diplopia.Hypertension and hematocrit are non-risk factors for diplopia after ALI.

Objective To study the different ischemic characteristics of cerebral gray matter and deep white matter in patients with chronic cerebral artery severe stenosis or occlusion. Methods A retrospective study was conducted on 30 patients with chronic unilateral cerebral artery severe stenosis or occlusion from April 2014 to April 2018 in our hospital. Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time of peak time (TTP) and time to delay(TTD) of cerebral cortex gray matter and deep white matter in the blood supply area of the responsible artery (the affected side) and the contralateral hemisphere (the healthy side) were measured. Statistical analysis of the perfusion parameters of cerebral cortex gray matter and deep white matter in the affected side and contralateral side were performed using SPSS13.0 software package. T test was used for variance homogeneity, and t′test was used for variance discrepancy, and P<0.05 was statistically significant. Results The average values of CBF and CBV of the ipsilateral and contralateral cerebral cortex were increased than those of ipsilateral and contralateral cerebral deep white matter respectively(P<0.01). MTT, TTP and TTD of the ipsilateral and contralateral cerebral cortex were decreased than that of ipsilateral and contralateral cerebral deep white matter (P<0.01); CBF of ipsilateral cerebral cortex and CBV of ipsilateral cerebral deep white matter were not different from those of the contralateral cerebral cortex and deep white matter respectively, but CBF of ipsilateral cerebral deep white matter is decreased than that of the contralateral deep white matter (P<0.01). CBV of ipsilateral cerebral cortex is increased than that of the contralateral cerebral cortex (P<0.01). MTT, TTP and TTD of ipsilateral cerebral cortex and deep white matter were increased than those of contralateral cerebral cortex and deep white matter respectively(P<0.01). Conclusion Deep cerebral white matter perfusion decreased more significantly than cortical gray matter in the supply region of chronic cerebral artery severe stenosis or occlusion. CT perfusion imaging can quantify the degree of chronic cerebral ischemia and can provide quantitative diagnostic information for clinical treatment and efficacy evaluation.