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Objective To investigate the application value of quantitative relaxation parameters based on synthetic MRI technology in the differential diagnosis of parotid gland tumors.Methods Conventional MRI and synthetic MRI data of 59 patients with patho-logically confirmed parotid gland tumors were analyzed retrospectively.T1,T2,and proton density(PD)values of the tumor were extracted from T1,T2 and PD mapping.The differences in quantitative relaxation parameters of pleomorphic adenomas,Warthin tumors,and malignant tumors were further compared.Diagnostic performance of each quantitative relaxation parameter was assessed and com-pared via receiver operating characteristic(ROC)curve and DeLong test.Results T2 value was significantly higher in pleomorphic adenomas than that in malignant tumors(P<0.05).The T1,T2,and PD values of pleomorphic adenomas and malignant tumors were significantly higher than those of Warthin tumors(P<0.05).The area under the curve(AUC)of the T2 value in differentia-ting pleomorphic adenomas from malignant tumors was 0.794.The AUC for T1 value(0.939)in differentiating Warthin tumors from malignant tumors was significantly higher than that of T2(0.873,P=0.341)and PD(0.927,P=0.891)values,without sta-tistically significant difference.The AUC for T2 value(0.968)in differentiating pleomorphic adenomas from Warthin tumors was significantly higher than that of T1(0.931,P=0.360)and PD(0.876,P=0.120)values,without statistically significant difference.Conclusion Quantitative relaxation parameters based on synthetic MRI technology may contribute to differentiating pleomorphic adenomas,Warthin tumors,and malignant tumors of the parotid gland.
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Objective To observe the value of zero echo time(ZTE)3.0T MRI for detecting lung cancer nodules.Methods Totally 126 lung cancer patients(176 lung nodules)were prospectively enrolled and underwent 3.0T MR axial lung scanning,including T1-volumetric interpolated breath-hold examination(VIBE),T2-BLADE,T2-half-Fourier acquisition single-shot turbo spin-echo(HASTE)and ZTE sequences.The consistency between ZTE MRI and previous CT for displaying characteristics of pulmonary nodules was analyzed,and the sensitivity of different MR sequences for detecting pulmonary nodules were observed.Results Among 176 pulmonary nodules showed on CT,ZTE MRI detected 140 and missed 36 ones.The consistency between ZTE MRI and CT for displaying the maximum diameter and actual maximum diameter of pulmonary nodules were both good(ICC=0.954,0.943,both P＜0.001),and the difference between ZTE MRI and CT was small.The consistency between ZTE MRI and CT for displaying tracheal vascular bundles,pleural indentation and internal bronchial inflation signs were all good(Kappa=0.894,0.912,0.917),while for displaying the type and shape of nodules were both moderate(Kappa=0.661,0.501).The sensitivity of ZTE MRI for detecting pulmonary nodules was higher than that of other individual MR sequences(all P＜0.05),of combination of ZTE and T2 BLADE was higher than that of other sequence combinations(all P＜0.05).Conclusion ZTE 3.0T MRI could be used to detect lung cancer nodules,which was superior to conventional MRI.Combination of ZTE 3.0T MRI with T2-BLADE could improve the sensitivity for detecting pulmonary nodules.
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Objective:To dynamically trace the migration and therapeutic effects of human bone marrow mesenchymal stem cells (MSCs) in mice with liver injury after cell transplantation through in vivo bioluminescent imaging (BLI).Methods:The MSCs were transfected with the lentivirus CMV-Luciferase2-mKate2 and mKate2 positive cells were purified and screened by fluorescence-activated cell sorting (FACS) after 96 h. The purified MSCs-R (MSCs-CMV-Luciferase2-mKate2) were used by in vitro and in vivo BLI. The mice (male BALB/c nude mice) were divided into 4 groups with 9 mice per group by random number table method, including (1) Liver injury experimental group: The liver injury model was established by intraperitoneal injection of CCl 4, and MSCS-R transplantation through spleen injection was performed 24 h later; (2) Control experimental group: The same volume of phosphate buffer (PBS) was injected intraperitoneally, and MSCS-R transplantation through spleen injection was performed 24 h later; (3) Liver injury group: Liver injury model was established and PBS was injected into the spleen;(4) Blank group: The mice were intraperitoneally injected of PBS.BLI was performed daily after cell transplantation until light signals disappeared in the liver region, and the pathological examination of liver tissue was obtained 14 d after MSCs-R transplantation. Linear regression analyses were performed to determine the correlation between the optical signal intensity and the number of cells, and statistical differences of the optical signal intensity between liver injury experimental group and control experimental group were evaluated using the Student′s t test. Results:The MSCs were readily transfected with lentivirus CMV-Luciferase2-mKate2 for 96 h. The transfected MSCs were purified by FACS and more than 95% of MSCs were mKate2 positive. The optical signal intensity of MSCs-R detected by BLI in vitro significantly correlated with cell numbers in vitro (R 2=0.980). In both of liver injury experimental group and control experimental group, cell migration to the liver was observed on the first day after intrasplenic transplantation of MSCs-R, and the optical signal intensity in the area of liver of liver injury experimental group was higher than that of control experimental group ( t=15.476, P<0.001). The optical signal intensity in the hepatic area was observed in 11 d after transplantation in liver injury experimental group, compared to control experimental group in 5 d. Optical signal was not detected in mice in the other two groups. Histopathology showed that the degree of liver injury after MSCs-R transplantation was significantly lower in liver injury experimental group than control experimental group. Conclusions:The dynamical migration of MSCs transplanted to the spleen and settled in the damaged liver could be tracked by BLI, and liver injury can prompt MSCs directionally migrate to the damaged tissues and play their role in repairing liver injury.