Objective To explore the feasibility of MR imaging for tumor-associated macrophages. Methods BALB/c mice and BALB/c ( nu/nu) nude mice were randomly divided into 6 groups ( before injection, 6, 24, 48, 72 hours and 7 days after injection) and 5 groups (before injection, 6, 24, 48 and 72 hours after injection) with each group of 3 animals, respectively. Macrophages ( RAW 264. 7) were incubated with HSA-IONPs ( dopamine/HSA coating iron oxide nanoparticle) containing 20 μg Fe/ml for 24 hours. Then, 5 x 106 labeled macrophages were collected and injected into subcutaneous 4T1 tumorbearing BALB/c mice and 22B tumor-bearing nude mice via tail vein. At different time points described above, all animals performed transverse and coronal T2-weighted MR scans using a 7. 0 T MR imaging unit.After sacrifice at different time points, tumor, liver and other organs were removed and processed for histological examination. Cytotoxicity of HSA-IONPs were assayed by MTT test, Statistics analysis adopt SPSS 11.5, the differences among groups were analyzed by one-way ANOVA. The difference was regarded as statistically significant when P <0. 05. Image J 1.42 software was used for the quantitative measurement of MR signal intensity. Results Effective cell labeling was confirmed by Prussian blue staining and transmission electron microscopy (TEM ). Iron uptake of single cell was 6. 19 pg. The mean absorbance values of cells incubated with HSA-IONPs for 24 hours in each group were 1. 95 ±0.19, 1. 82 ±0. 29,2. 10 ±0. 14, 1. 96 ±0. 18, 2. 05 ±0. 27 and 2.17 ±0. 22 respectively at different concentrations (5, 10,20, 40, 80, 160 μg/ml). Compared with that in control group (2. 00 ±0. 07), the absorbance values of cells in each group were not significantly different (F = 1.24,P>0. 05). There was a significant linear positive correlation between the labelled macrophage numbers and MR R2 values (r = 0. 99 ,P < 0. 05). In 4T1 tumor model, significant low signal intensity was found on T2WI surrounding the necrosis and cystic degeneration 6 hours after macrophage injection, with a signal reduction of 59.4%. The signal of tumor parenchyma showed no significant change, with signal reduction of 4. 8%. Irregular low signal ring could be seen at the junction of necrosis and parenchyma area at 24 hours after injection, with a signal reduction of 46. 8% and the signal loss was restored to 96. 8% around the necrosis and cystic degeneration. In 22B tumor model, multiple small scattered foci of low signal intensity were presented on T2WI around the necrosis and cystic degeneration 6 hours after macrophage injection with a signal drop of 46. 8% and reduced at 24 hours. 2, 3 or 7 days after macrophage injection, the morphology and location of low signal intensity were similar to those at 24 hours after injection on T2WI. But the signal intensity gradually decreased. The presence of labelled macrophages imaged by MRI were verified by pathology. Conclusion MRI is feasible for the delineation of tumor-associated macrophages. 24 hours after macrophage injection is the optimal time point for the assessment of macrophage migration and infiltration of tumor on T2WI. MRI can be used to evaluate the perfusion and neovascularization of tumor 6 hours after macrophage injection.

Objective To explore the characteristic appearance of MR imaging of atypical craniopharyngioma and improve the diagnostic accuracy.Methods 8 atypical craniopharyngioma were analyzed retrospectively by MR imaging,which had been confirmed by pathology.Results 3 atypical craniopharyngiomas were cystic lesions, 2 were solid lesions, and rest 3 were solid-cystic lesions.The cystic lesion presented variable intensities on T1-weighted imaging (T1WI);and the wall was remarkably enhanced and uniform in thickness.The solid lesions presented hypointense on diffusion weighted imaging (DWI), and reticular enhancement.Solid-cystic tumors presented heterogeneous enhancement.In these lesions,4 lesions in sellar and suprasellar regions were misdiagnosed as pituitary macroadenoma,because of the unclear boundary between the lesions and pituitary gland.2 lesions in superasellar region were misdiagnosed as germinoma, for the remarkable enhancement.And 2 cases in superasellar region were misdiagnosed as pilocytic astrocytoma,for indistinct boundary between lesions and pituitary stalk and optic chiasma.Conclusion The MR imaging characteristics can help distinguish atypical craniopharyngioma from pituitary macroadenoma,sellar germinoma and pilocytic astrocytoma.

Objective To investigate the application value of multi-slice CT enterography (MSCTE)in diagnosing intestinal tuberculosis (ITB)and Crohn’s disease (CD).Methods MSCTE findings were retrospectively analyzed in 25 patients with ITB and in other 25 patients with CD diagnosed through endoscopy,pathologic examination and clinical follow-up.Statistical analysis was performed to find out the difference in CT findings between the ITB and CD.Results 25 patients with CD included the involved ileum in 23,involved duode-num and jejunum in 8,multiple segmental lesions in 20,asymmetrically thickened intestinal wall in 20,hierarchical reinforcement in 1 9,mesenteric vascular hyperplasia in 20,fibrofatty hyperplasia in 18,peritoneal abscess or fistula in 8,anal fistula in 1,and pseu-do-diverticulum formation in the intestinal wall on the opposite side of the mesentery in 2.Meanwhile,the other 25 patients with ITB included the involved terminal ileum in 25,symmetrically thickened intestinal wall in 23,annular enhancement of lymph nodes in 11,thickened peritoneum and omentum together with distinct enhancement,or intestinal adhesion,or ascites appeared in 15.The CD was more likely to represent multiple segmental lesions,asymmetrically thickened intestinal wall,hierarchical reinforcement,mesenteric vascular hyperplasia,fibrofatty hyperplasia,and peritoneal abscess or fistula formation (P <0.05).Meanwhile,the ITB was more likely to represent the lesion only in ileum,symmetrically thickened intestinal wall,and annular enhancement of lymph nodes (P <0.05).Conclusion MSCTE shows promising clinical application in diagnosis and differential diagnosis of CD and ITB.

Objective To assess the changes in normal-appearing white matter fiber tracts of the brainstem in patients with relapsing-remitting multiple sclerosis (RRMS) quantitatively with diffusion tensor imaging (DTI). Methods Fifty patients with RRMS were recruited, and twenty five healthy volunteers with the same gender and age were selected as controls. Conventional magnetic resonance imaging and DTI was performed. Quantitative indexes as fractional anisotropy (FA) and mean diffusivity (MD) values in the brainstem fiber tracts, including corticopontine tract/corticospinal tract (cpt/cst), superior cerebellar peduncle (scp), middle cerebellar peduncle (mcp), inferior cerebellar peduncle (icp), and medial lemniscus (ml) were measured and analyzed. Results In comparison with controls, decreasing FA values in cpt/cst (L:P=0.030; R:P=0.020), icp (L:P=0.030; R:P=0.037), scp (L:P=0.036; R:P=0.041) and ml (L:P=0.014; R:P=0.035), as well as increasing MD values in cpt/cst (L:P=0.004; R:P=0.046), icp (L:P=0.047; R:P=0.011), scp (L:P=0.021; R:P=0.011) and ml (L:P=0.002; R:P=0.044) were found in patients with RRMS. No significant difference of FA and MD values was found in mcp between patients with RRMS and controls (P＞0.05). None of the MD or FA values in fiber tracts of the brainstem in patients with RRMS was correlated with brain parenchymal fraction (BPF) or T2 lesion volume. Conclusion The relevant abnormalities which were found in normal-appearing white matter fiber tracts of the brainstem in RRMS patients by DTI scanning suggested pathological changes. It is presumed that the changes may be due to demyelination caused by hiding lesions.

Objective To evaluate the value of stress perfusion cardiovascular magnetic resonance in the diagnosis of coronary ar-tery disease.Methods Relevant literatures about stress perfusion cardiovascular magnetic resonance in the diagnosis of coronary ar-tery disease were searched.According to the recommended contents of the Cochrane Collaboration,we set inclusion criteria and screen literatures.Using software STATA 12.0 and Meta-disc 1.4,we analyzed the data ,including the heterogeneity,publication bias,subgroup analysis,Meta-regression,clinical application,pooled sensitivity(SEN),specificity(SPE),positive likelihood ratio (PLR),negative likelihood ratio(NLR),diagnostic odds ratio(DOR)and 95%confidence interval(95%CI),we drew the summary receiver operating characteristic curve(SROC)and calculated the area under the curve(AUC).Results Twenty-nine literatures were included,the pooled SEN,SPE,PLR,NLR,DOR and 95%CI were 0.90(0.89~0.92)、0.78(0.75~0.80)、4.03(3.32~4.91)、0.14 (0.11~0.18)、32.54(22.25~47.60)respectively.The AUC of SROC was 0.907 8.Conclusion The current evidence indicates that stress perfusion cardiovascular magnetic resonance has a high diagnostic accuracy for detection coronary artery disease.However, the relatively high false positive rate was found due to the medium specificity.

Objective To investigate the functional and structural changes of connectivity of default mode network (DMN) in relapsing-remitting multiple sclerosis (RRMS) by functional MRI (fMRI) and diffusion tensor imaging (DTI) and to study the relationship between them.Methods Twenty-seven RRMS patients(clinically diagnosed as RRMS)and 27 healthy volunteers (matched to the patients in age and gender) were selected to participate in this study.All the subjects underwent 3.0 T MR scanning.Softwares such as DPARSF,MICA,TrackVis were used for data post-processing.Medial prefrontal cortex (mPFC) and posterior cingulate cortex(PCC) of DMN were chosen as ROIs,and functional and structural changes of DMN and the relationship between them were analyzed.Values of r reflecting the functional connectivity and fractional anisotropy(FA) of two groups were obtained.Then statistical analysis was performed by using student t test and Pearson correlation analysis.Results The DMN space pattern of the RRMS patients was mostly identical to that of controls,but with specific difference in the connectivity strength with respect to that of controls.Particularly,the patient group showed increased DMN connectivity in the mPFC,but decreased connectivity in the inferior parietal lobule (IPL) and PCC.Compared with controls,the r value (0.695 ±0.151 vs.0.796±0.085),FA value(0.261 ±0.012 vs.0.285 ±0.017) between mPFC and PCC in RRMS patients were decreased (t =-3.020,-6.206,P ＜ 0.05).In addition,functional connectivity (r value) was found to correlate with structural connectivity(FA value) between the PCC and mPFC (r =0.704,0.735,P ＜ 0.01).The number of MS lesion,had no correlation with r value or FA value (P ＞ 0.05).Conclusions The functional connectivity and structural connectivity of DMN change in RRMS patients.The functional connectivity and structural connectivity between mPFC and PCC are both decreased in RRMS patients compared with the controls.The injury of structural connectivity may be the structural basis of the decrease of functional connectivity.

Objective To explore CT and MRI features of peripheral primitive neuroectodermal tumors (pPNET) .Methods CT and MRI findings were retrospectively analyzed in 9 cases with pPNET confirmed by pathology .Of them ,8 patients underwent CT imaging ,and 5 patients underwent MR imaging .Results The lesions occurred in head and neck in 2 cases ,chest in 3 cases ,scrotum in 1 case ,right scapular region in 1 case ,and lower extremity in 2 cases .The lesions were more solitary (7/9) with round ,lobular or irregular shape .The longest diameter was between 1 .6 cm -13 .8 cm ,and the median diameter was 6 .2 cm .8 cases had blurred boundary .On CT plain scanning ,the lesions were mixed density with predominant isodensity .On MR imaging ,the lesions were slightly T1 hypointensity and heterogeneous T2 hyperintensity .Enhancement patterns were varied ,and the common way was mild‐to‐moderate heterogeneous enhancement .3 cases of them were closely associated with bone ,and showed osteolytic bone destruction . Conclusion The CT and MRI features of pPNET has lack characteristics ,CT and MR imaging have some value for localization diagnosis .

Objective To analyze the multi-slice computed tomography (MSCT) enhanced findings in the patients with primary small intestinal stromal tumor(SIST),and to probe the relationship between the imaging findings and the pathologic risk in order to improve the diagnostic accuracy.Methods Thirty patients with primary SIST confirmed by surgical pathology were enrolled in this study.Characterization and compassion of the clinical manifestations and MSCT enhanced findings were carried out between the pathologic low-and high-risk groups.Furthermore,the relationship was analyzed between the enhanced findings and the pathologic risk.Results Among all 30 patients with primary SIST,the lesion was located at duodenum in 5 patients (16.7％),at jejunum in 16 (53.3％),and at ileum in 9 (30％).14 patients were classified in the low risk group with the lesion with the average length of (3.8±0.9) cm,and other 16 in the high-risk group with lesion with the average length of (7.0 ± 1.4) cm.There were no statistical differences between the low-and high-risk groups in CT value in plain and venous phase,and in added value in arterial,venous and delayed phases.However,the significantly differences were observed in CT value in arterial and delayed phases between two groups (P＜0.05).Conclusion MSCT may effectively evaluate the pathologic risk of primary SIST.There are significant differences of the enhanced findings between the low and high-risk groups,which can provide important apreoperative classification for the therapy.

Objective To explore the diagnostic value of DTI for prostate cancer.Methods From October 2009 to December 2010,44 patients suspected of prostate cancer received MRI and DTI.The data of MRI and DTI were analyzed retrospectively.By histopathology,prostate cancer was proved in 16 patients,and benign prostatic hyperplasia ( BPH ) was proved in 28 patients.Differences in ADC and FA values between prostate cancer and BPH were compared by independent samples t test.Diagnostic accuracy of FA value and ADC value for prostate cancer was analyzed by using ROC curve,and the diagnostic threshold of FA value and ADC value for prostate cancer was determined.Results The mean FA value of the tumor regions and BPH were 0.308 +0.084 and 0.203 ±0.029,respectively.The mean ADC value of the tumor regions and BPH were (0.883 +0.192) × 10 -3 mm2/s and ( 1.408 ±0.130) × 10-3 mm2/s,respectively.There were statistically significant differences in ADC and FA values between tumor regions and BPH (t values were 4.833 and 10.779 respectively,P＜0.01).The ADC value area under curve of ROC was 0.996 (95％ CI was 0.984 to 1.007) ; the FA value area under curve of ROC was 0.904(95％ CI was 0.812 to 0.996) ; Combined the FA and ADC value area under curve of ROC is 0.996(95％ CI was 0.984to 1.007) ; Using the ADC value of 0.725 × 10 3 mm2/s as the ROC cut off point,the diagnostic sensitivity and specificity were 100.0％ and 96.0％,respectively; Using the FA value of 0.311as the ROC cut off point,the diagnostic sensitivity and specificity was 100.0％ and 68.7％,respectively.Conclusion DTI imaging can provide valuable information for prostate cancer diagnosis and differential diagnosis,and improve the diagnosis ability of prostate cancer.

Objective To explore the value of MR dynamic contrast-enhancement in diagnosis and differential diagnosis of infiltrating ductal carcinoma of breast at 3.0T MR magneton.Methods 17 cases of breast infiltrating ductal carcinoma underwent plain MRI and MR dynamic contrast-enhanced scan using 3.0T MR scanners with dedicated breast coil.All cases were confirmed by surgery and pathology.MRI signal intensity,morphology and hemodynamic characteristics of lesions were analysed.Results 17 breast infiltrating ductal carcinomas in 17 cases all appeared as masses,low(8/17)or equal(9/17)signal intensity on T_1WI,high(14/17)or equal(3/17)signal intensity on T_2WI.On morphology,the lesions were irregular and lobulated in shape(82.4%,14/17);undefinite margins(12/17)or non-smooth margins(15/17),glitch sign or astral sign(7/17);the lesions showed non-uniform marked enhancement(10/17)or ring enhancement(5/17)after intravenous administration of contrast agent.82.4%(14/17)of the lesions,the blood vessels could be seen gathering around the lesions on the maximum intensity projection(MIP)image.On hemodynamics,the early enhanced ratio for all cases was over 90%;88.2%(15/17)of the lesions,peak enhancement was less than three minutes;the time-signal intensity curve of the lesions appeared as type Ⅱ was 35.3%(6/17)and type Ⅲ was 58.8%(10/17)mostly.Conclusion Dynamic contrast-enhanced MRI manifestations of breast infiltrating ductal carcinoma are of certain characteristics,which may contribute to the diagnosis and differential diagnosis.