Objective To explore the diagnostic value of 18F-FDG PET/CT in biliary obstruction.Methods Totally,28 biliary obstruction patients were divided into benign obstruction group (n =11) and malignant obstruction group (n =17)according to the cause of obstruction.Imaging characteristics of 18F-FDG PET/CT and maximal standard uptake value (SUVmax) were compared between the two groups.Efficacy of PET/CT and MRI in the diagnosis of obstructive jaundice were compared.Results In 28 cases,no or mild dilatation of biliary tract accounted for 53.57％ (15/28),moderate to severe dilatation of biliary tract accounted for 46.42％ (13/28).Among the malignant obstruction group,2 cases of hilar cholangiocarcinoma,5 cases of bile duct carcinoma,6 cases of carcinoma of the head of pancreas,and 4 cases of ampullary carcinoma were included,18F-FDG PET/CT showed proximal high metabolic nodules of the obstruction site in 14 cases.Among the benign obstruction group,7 cases were bile duct inflammatory stricture,of which 4 cases with bile duct stones.18F-FDG PET/CT showed a slight increase with patchy or nodular mild metabolism in 6 cases.There were 4 cases of autoimmune pancreatitis.The imaging 18 F-FDG PET/CT demonstrated multi-segmental or multiple nodular enlargement of the pancreas,with generally increased metabolism.SUVmax of malignant obstruction group (6.88± 2.81) was significantly higher than that of benign obstruction group (4.20± 1.70;t=3.143,P＜0.05).The sensitivity,specificity and accuracy of 18F-FDG PET/CT and MRI in the diagnosis of malignant obstructive jaundice were 94.12％ (16/17) and 58.82％ (10/17;x2=4.086 5,P=0.043),81.82％ (9/11) and 63.64％ (7/11;x2=0.229 2,P=0.632),89.29％ (25/28) and 60.71％ (17/28;x2 =4.666 7,P=0.031),respectively.Conclusion 18F-FDG PET / CT has a great value in the diagnosis of obstructive jaundice,which is of great significance for clinical decision-making.

Objective To investigate the predictability of occult lymph node metastasis (OLM) using metabolic parameters of pretreatment 18F-FDG PET-CT in squamous cell lung carcinoma patients manifesting clinical negative node (cN0).Methods A total of 91 cN0 squamous cell lung carcinoma patients who underwent curative surgery and pretreatment 18F-FDG PET/CT were enrolled retrospectively.Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of primary tumor were obtained with standardized uptake value (SUV) threshold of 2.5.ROC curve analysis was performed to quantify the predictive value of SUVmax,MTV,TLG and the maximal tumor length.To identify risk factors for OLM,univariate and multivariate Logistic regression analysis were performed.Results Of 91 patients,26 had OLM.Significantly higher SUV MTV,TLG and the maximal tumor length were observed in patients with OLM compared with negative occult lymph node metastasis (all P＜0.05).ROC curve showed that the cutoff point of SUVmax,MTV,TLG and the maximal tumor length were 12.76,31.17 cm3,153.13 and 3.8 cm,respectively.Univariate analysis showed correlation of tumor location (central),the maximal tumor length,SUVmax,MTV and TLG with the rate of OLM (all P＜0.05).In multivariate analysis,tumor location (central),the maximal tumor length ＞3.8 cm and MTV ＞31.17 cm3 showed association with increased risk of OLM (all P＜0.05).Conclusion MTV in 18F-FDG PET/CT is an independent factor for predicting OLM in patients with cN0 squamous cell lung carcinoma,which can be used to guide surgical planning.

Objective To explore correlation between ultrasonic characteristics of femoral artery atherosclerotic plaques and non-ST-elevation acute coronary syndrome (NSTE-ACS).Methods Seventy-two patients with coronary heart disease (CHD) coexisting carotid artery and femoral artery plaques were divided into NSTE-ACS group (n=42) and chronic ischemic syndrome (CIS) group (n=30).The enhanced intensity (EI),volume,shape and internal echo level (EL) of plaques were detected with contrast-enhanced ultrasonic imaging and three-dimensional ultrasound combined with ultrasonic greyscale intensity quantitative analysis,and all parameters were analyzed between the two groups.Results EI and the proportion of irregular artery plaques were higher,and EL was lower in NSTE-ACS group than those in CIS group (all P＜0.05).EI,EL and shape of carotid artery and femoral artery plaques were correlated with NSTE-ACS (all P＜0.05).EI and EL of femoral artery plaques were risk factors for NSTE-ACS (OR=1.222,1.177,P＜0.05).Areas under ROC curve of EI and EL of carotid artery plaques were 0.801 and 0.757 (both P＜0.001),and those of femoral artery plaques were 0.814 and 0.774,respectively (both P＜0.001).Conclusion Neovascularization,shape and internal echo are correlated with NSTE-ACS,and the correlation of femoral artery plaques with NSTE-ACS is more significant than that of carotid artery plaques.Detecting ultrasonic characteristics of femoral artery atherosclerotic plaque can provide references to early identify unstable plaque and screening high-risk patients with CHD.

Objective To investigate the value of dual-exponential model intravoxel incoherent motion (IVIM) DWI and conventional single-exponential DWI model based on readout segmentation echo-planar (RS-EP) sequence in differential diagnosis of simple rhinitis and chronic hypertrophic rhinitis.Methods Totally,20 patients confirmed by pathology were enrolled in this study and all of them underwent IVIM DWI and conventional DWI.The pure diffusion (D),pseudo-diffusion (D*),perfusion fraction (f) and conventional ADC maps were obtained respectively.The quantitative parameters of anterior,middle,posterior regions of inferior nasal concha mucosa were measured.Comparative statistical analysis was performed for comparing two groups and three regions.ROC analysis was conducted to assess the diagnostic performance.Results The ADC and D values in the simple rhinitis group were (1 938.84 ± 170.46) × 10-6 mm2/s,and (1 698.91 ±145.17) × 10-6 mm2/s.In chronic hypertrophic rhinitis group,the ADC value was (1 681.76± 132.21) × 10-6 mm2/s,and the D value was (1 439.39 ± 101.26)× 10-6 mm2/s.There were significant differences between the two groups (both P＜0.05).No significant differences were found for D* and f values between two groups (both P＞0.05).ADC values increased significantly from anterior region,middle region to posterior region (all P＜0.05).No significant difference was found for D* value among three regions (P＞0.05).ROC analysis demonstrated a higher area under the curve (AUC) for D value than ADC value (0.932±0.044 vs 0.896±0.058) with sensitivity,specificity,accuracy,positive and negative predictive values of 92.31％,93.75％,90.00％,93.75％,85.71％.Conclusion Based on RS-EP sequence,both IVIM DWI model and conventional single-exponential DWI model demonstrated great value in differential diagnosis of simple rhinitis and chronic hypertrophic rhinitis,and the IVIM-derived D value exhibited a higher diagnostic performance than the conventional ADC value.

Objective To analyze the relationship between internal carotid artery (ICA) stenosis and ipsilateral retinal vascular calibers,and to investigate the feasibility and accuracy of changes of retinal vascular calibers for assessment of ICA stenosis.Methods Unilateral ICA and ipsilateral retinal vascular of 243 patients were enrolled based on CTA and fundus imaging.Patients were divided into 4 groups according to the highest ICA stenosis rate (Rmax),i.e.no stenosis group,mild stenosis group,moderate stenosis group and severe stenosis group.The differences of retinal vascular calibers among four groups and correlation between retinal vascular calibers and ICA stenosis were analyzed.Results The average central retinal vein equivalents (CRVE) in moderate ICA stenosis group and severe stenosis group were significantly wider than those in the other two groups (all P＜0.05).There was no statistical significance of central retinal artery equivalent (CRAE) nor retinal arteriolar-to-venular ratio (AVR) among groups (both P＞0.05).Rmax was positively correlated with CRVE (r=0.27,P＜0.01) and negatively correlated with AVR (r=-0.16,P＜0.05),whereas Rmax had no correlation with CRAE (P＞0.05).CRVE was the impact factor of ipsilateral Rmax (B=0.243,P＜0.01),but the adjusted R2 of the model was weak (0.173).Area under the ROC curve of CRVE was 0.619 in assessing ICA moderate and severe stenosis,and taking threshold as 229.5μm,the sensitivity and specificity was 80.3％ and 40.1％,respectively.Conclusion CRVE can assess and predict ICA stenosis to some extent,but the diagnosis efficacy is limited.

Objective To explore the diagnostic value of parametric imaging of CEUS in different cervical lymphatic diseases.Methods One hundred eleven patients diagnosed with cervical lymphadenopathy were included.All of the patients underwent parametric imaging of CEUS.According to the pathological results,all patients were divided into reactive hyperplasia group,tuberculosis group,metastasis group and lymphoma group.The features of perfusion phases (perfusion during the artery phase,or perfusion during the artery and parenchymal phase) and perfusion uniformity (homogeneous perfusion or heterogeneous perfusion) were compared among four groups.According to the pathological results,the reactive hyperplasia group and the tuberculosis group were merged into a benign group,and the metastasis group and the lymphoma group were merged into a malignant group.Then,the artery perfusion phase was regarded as benign,and the artery and parenchymal perfusion phase was regarded as malignant.The consistency between parametric imaging of CEUS and the pathological results was compared in two groups.Results The difference of perfusion phase and perfusion uniformity within the four groups had a statistical significance (all P＜0.05).The differences of perfusion phase between the reactive hyperplasia group and the metastasis group,the reactive hyperplasia group and the lymphoma group,the tuberculosis group and the metastasis group were statistical significant respectively (all P＜0.008).The differences of perfusion uniformity between the reactive hyperplasia group and the tuberculosis group,the reactive hyperplasia group and the lymphoma group,the lymphoma group and the tuberculosis group,the lymphoma group and the metastasis group were statistical significant respectively (all P＜0.008).The perfusion phase between the benign group and the malignant group had a statistical significance (P＜0.005),but the perfusion uniformity had no statistical significance in two groups.The consistency was good between the parametric imaging and the pathological results.Conclusion The parametric imaging of CEUS can offer valuable diagnostic information for the cervical lymph nodes underdetermined by conventional ultrasound.

Objective To observe MRI features of intracranial changes in phenylketonuria (PKU) patients.Methods Brain MRI findings of clinically diagnosed 13 PKU patients were analyzed retrospectively.The structure and signal changes of cerebrum,cerebellum and brainstem were observed.Results Posterior horn and triangle high signals were shown in white matter of bilateral lateral ventricle of all 13 patients on T2WI,while the optic radiation was spared.Periventricular white matter abnormal signals at body and anterior horn bilateral lateral ventricle (n=12),bilateral basal ganglia involvement (n=1),extensive white matter involvement (n=1),backward myelination and agenesis of corpus callosum (n=3),and mild macrogyria deformity (n=1) were found.The high signals in lateral periventricular white matter were shown on DWI,with reduction of ADC values in 6 cases.Conclusion Abnormal high signals in brain posterior horn and triangle white matter,optic radiation spared,and corpus callosum and cortical malformations are brain MRI appearances in brain of PKU.

Objective To quantify the perfusion parameters of normal pancreas and pancreatic carcinoma with three-dimension (3D) fast spoiled gradient echo dynamic contrast enhanced (DCE) MRI on 3.0T MR system, and to assess the value of 3D DCE-MRI in the diagnosis of pancreatic carcinoma. Methods Thirty-four patients with pathology verified pancreatic carcinoma and 31 control subjects with normal pancreas (without pancreatic diseases) underwent DCE-MRI with 3D LAVA sequence of ten phases. The data were processed on ADW 4.2 workstation. The perfusion parameters of the head, body and tail of normal pancreas, together with lesion and non-lesion area of pancreatic carcinoma were measured and statistically analyzed, including signal enhancement ratio at 30 s after injection (SER_(30)), signal enhancement ratio at 90 s after injection(SER_(90)), positive enhancement integral (PEI), time to peak (TTP) and maximum slope of increase (MSI). Results There was no significant perfusion difference among head, body or tail of normal pancreas (P>0.05). The difference of SER_(30), PEI, TTP and MSI between lesion and non-lesion region of carcinous pancreas was significant (P<0.05). The TTP between normal pancreas and the non-lesion region of carcinous pancreas was significantly different (P<0.05). Conclusion Normal pancreas has no regional perfusion difference. The data from DCE-MRI provide reliable information for the diagnosis of pancreatic cancer, and for the assessment of the invasion of pancreatic carcinoma. The difference in TTP between the normal pancreas and non-lesion region of carcinous pancreas suggest the existing of potential lesions.

Objective To investigate the alteration of the default-mode network (DMN) in the patients with minimal hepatic encephalopathy (MHE) using resting functional MRI, and to explore its underlying clinical significance. Methods Fourteen MHE patients and 14 age-matched normal controls underwent standard resting state functional MRI scan. The components representing DMN were picked out after separation of independent component analysis. One and two sample t-tests were used to observe the changes of DMN in the patients in contrast to the controls. Results Typically spatial distributions of the DMN were found in both MHE patients and controls. Comparison results revealed that there was significantly reduced functional connectivity in the left posterior cingulate cortex, bilateral anterior cingulate cortex, bilateral medial prefrontal cortex, left parahippocampal cortex in MHE patients, while functional connectivity increased in the right precuneus. Conclusion Resting state functional MRI can be used to observe DMN changes in MHE patients. In MHE patients, there is reduced DMN activation in the widespread regions, while the activation of right precuneus increases.

Objective To evaluate the therapeutic effect of intramyocardial controlled releasing base fibroblast growth factor (b-FGF) stent combined with transplanting bone marrow-derived mesenchymal stem cells (BM-MSCs) in porcine acute myocardial infarction (AMI) models. Methods Eighteen porcines were divided into three groups (each n=6):transmyocardial revascularization (TMR)+naked stent (control group), TMR+b-FGF stent (b-FGF group) and TMR+b-FGF stent+BM-MSCs (b-FGF+BM-MSCs group). Acute myocardial infarction models were induced by ligating the left anterior descending artery in 18 porcine. In the control and b-FGF group, naked stents, b-FGF stents and b-FGF stent+BM-MSCs were implanted into TMR channels in the infarct and border zone. ~(99m)Tc-methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging were performed to evaluate changes in myocardial blood flow, and echocardiography and immunohistochemical studies were also performed. Results After 6 weeks, the quality of myocardial infarction, fractional shortening, neovascular density in b-FGF and b-FGF stent+BM-MSCs group were higher than those of control gruop (P<0.05), and in b-FGF stent+BM-MSCs group was higher than those in b-FGF group (P<0.05). Conclusion BM-MSCs combined with controlled releasing intramyocardial b-FGF stent can improve the flow of myocardial infarction area, promote angiogenesis and heart function, and the therapeutic effect which can be evaluated with myocardial SPECT imaging.