Objective The purpose of the present study is to compare the pharmacokinetic and biodistribution properties of 99Tcm N-mercaptopyridine-N-oxide (99 Tcm N-MPO) with 99 Tcm-sestamibi (99 Tcm-MIBI) in normal dogs, and to investigate the potential of 99TcmN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Methods Twelve healthy mongrel dogs were injected intravenously with 99TcmN-MPO (n = 6) or 99Tcm-MIBI (n = 6). Tracer kinetics in body fluids were determined by collecting blood of 1 ml via a femoral vein catheter at 30 s, 1,2,3,4,5, 10, 20, 30, 40, 60and 90 min post-injection (p. i.). The collected blood samples were weighed and counted for radioactivity in a γ-counter. Anterior and posterior planar γ-camera images were collected at 10, 20, 30, 60, 90, and 120 min after injection, with organ uptake quantified by region-of-interest (ROIs) analysis. For comparison, 99Tcm-MIBI was also evaluated in the same twelve dogs. Canine infarct models were set up by micro-invasive interventional embolization. SPECT images in the canine infarct model were collected 24 hours after myocardial infarction at 30 min and 60 min after the administration of 99Tcm N-MPO (n = 5) or 99Tcm-MIBI (n = 5). Results Both of 99Tcm N-MPO and 99Tcm-M1BI had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min [99TcmN-MPO: (35. 77 ± 6. 31)% ID/mg ,99Tcm-MIBI (34. 46 ± 6. 83) % ID/mg] and less than 5% at 30 min p. i. [99Tcm N-MPO(3. 11 ± 1.44) % ID/mg,99Tcm-MIBI (2.93 ±0. 39)% ID/mg] . After injection, 99TcmN-MPO showed significant accumulation in the myocardium and prolonged retention. This rapid liver clearance of 99TcmN-MPO led to favorable heart-to-liver ratios, reaching values of 0. 54 ±0. 06 at 10 min, 1.02 ±0. 06 at 30 min, and 1.38 ±0. 06 at 60 min p. i.In contrast, the heart/liver ratio of 99Tcm-MIBI remained low at all time points (0. 46 ± 0. 03 at 10 min,0. 63 ±0. 03 at 30 min, and 0. 62 ± 0. 12 at 60 min p. i.). SPECT imaging studies in canines with acute myocardial infarction indicated that good visualization of the left ventricular wall and perfusion defects could be achieved at 30 min after administration of 99TcmN-MPO, but not 99Tcm-MIBI. Conclusion The combination of high heart uptake and rapid liver clearance makes 99TcmN-MPO a promising new radiotracer for myocardial perfusion imaging.

Objective To investigate the effect of imaging parameters and postprocessing methods on the quality of MR imaging of short T2 components with 3D ultrashort TE (UTE) double echo pulse sequence. Methods 3D UTE double echo pulse sequence was performed on dry human femoral specimen and the tibial diaphyses, knee joints, and tendons of ankles of a group of healthy volunteers. To investigate the effect of different trajectory delays of the imaging system(-6, -3, -2, - 1,0, 1,2, 3 s), different flip angles(4°, 8°, 12°, 16°, 20°, 24°), different TEs (0. 08, 0. 16, 0. 24, 0. 35 ms)and different postprocessing methods(difference imaging of subtracted volume and non-volume UTE)on the 3D UTE MR imaging quality, the SNR and CNR were calculated and compared, and the artifacts of the images were analysed. Results The cortical bone, periosteum, tendon and meniscus showed high signal intensity on the images of UTE pulse sequence. The best SNR was acquired with 2 s trajectory delay. The best flip angle was 8° to 12° for the human UTE imaging in vivo. The highest CNR was obtained from the TE of 0. 08 ms. The longer the TE was, the more artifacts appeared. The SNR of difference imagewas improved when image subtraction was performed afer multiplanar reconstruction (MPR) of the primary double echo images.Conclusions The short T2 components show high signal intensity on the MRI of 3D UTE double echo pulse sequence. The imaging quality can be improved by shortening TE, using appropriate flip angle and performing subtraction for difference image after MPR of the primary double echo images.

Objective To determine whether the adjustment of the pusher of GTF was useful to decrease the degree of tilting of the femoral Ginther Tulip filter (GTF) in an in vitro caval model. Methods The caval model was constructed by placement of a 25 mm × 100 mm and two 10 mm ×200 mm Dacron graft inside a transparent bifurcate glass tube. The study consisted of two groups: left straight group (GLS) (n =100) and left curved group (GLC) (n = 100). In the GLC, a 10° to 20° angle was curved on the introducer.The distance (DCH) between the caval right wall and the hook was measured. The degree of tilting (DT) was classified into 5 grades and recorded. Before and after the GTF being released, the angle (ACM1, 2)between the axis of IVC and the metal mount, the distance (DCM1) between the caval right wall and the metal mount, the angle (ACF) between the axis of IVC and the axis of the filter and the diameter of IVC (DIVC) were measured. The data were analyzed with Chi-Square test, t test, rank sum test and Pearson correlation test. Results The degree of GTF tilting in each group revealed a divergent tendency. In group LC, the apex of the filter tended to be grade Ⅲ compared in group LS (x2 value 37. 491 ,P ＜0.01).The differences of most variables between GLS and GLC were considered as statistical significance(16. 60° vs.3.05°, 20.60° vs. 3.50°, -3.90°vs. -0.40°, 2.98 mm vs. 10.40 mm, - 10.95° vs. -0.485°,13. 17 mm vs. 10.06 mm, - 1.70° vs. 0.70°, t or Z values - 12. 187, - 12. 188, -8.545, -51.834,-11. 395,9. 562, -3. 596, P ＜ 0. 01). There exist significant positive correlation between ACM1 and ACF,ACM1 - ACM2 and DCH1 - DCH2 in each group, respectively(r values 0. 978,0. 344,0. 879,0. 627 ,P ＜0. 01),while significant negative associations are detected between DCH1 and ACF in each group , ACP and ACF in group LC(r values -0.974, -0.322, -0.702,P＜0.01). Conclusion The technique of adjusting the orientation of filter pusher had minimized the incidence and extent of GTF filter tilting in vitro.

Objective To assess the therapeutic effect of combination chemotherapy of gemcitabine and cisplatin by double way plus implantation of radioactive seed 125I implantation in treating stage Ⅲ non-small cell lung cancer. Methods Sixty cases with stage Ⅲ non-small cell lung cancer were randomly divided into two groups with random number table. In group A (in interventional treatment group, n = 30),the gemcitabine 1000 mg/m2 and one third of the cisplatin 100 mg/m2 was given using seldinger technique for transcatheter bronchial arterial infusion chemotherapy on day 1. Two-thirds of the cisplatin 100 mg/m2 was infused in veins on day 2 and 3. The gemcitabine 1000 mg/m2 was infused in veins on day 8, 21 days for a period. In group B (interventional - 125I groups), the method of combination chemotherapy of gemcitabine and cisplatin was the same as in Group A. After ten days of arterial perfusion, 125I seeds were implantated, 21 days for a period. All patients received at least 2 cycles. The imaging evaluation of patients after treatment standards included complete remission (CR), partial remission (PR), stable (SD),progressive disease (PD), effective rate (CR + PR)/30 and clinical benefit rate (CR + PR + SD)/30.Non-parametric rank sum test was used to compare short-term effect of the two groups treatment of two cycles.x2 test was used to compare year survival, Kaplan-Meier method was used to calculate median survival,log-rank test method was used to difference between the groups. Results In group A, there were 17 PR,9SD and 4 PD. The overall response rate was 56. 7% (17/30) and clinical beneficial rate was 86. 7% (26/30). In Group B, there were 2 CR, 21 PR, 7 SD. The overall response rate was 76.7% (23/30) and clinical beneficial rate was 100% (30/30). There was significant difference between the two groups (P =0. 036). In group A, the 1 year survival rate was 46. 7% (14/30) and the 2 year survival rate was 36. 7%(11/30), median survival time (MST) was 10 months . In group B, the 1 year survival rate was 76. 7%(23/30) and the 2 year survival rate was 63. 3% (19/30) , median survival time (MST) was 27 months.There was a significant difference between two group in 1 year survival rate (P = 0. 017), 2 year survival rate (P = 0. 039) and median survival time (P = 0. 006). Conclusion The treatment effects of Ⅲ stage non-small cell lung cancer by gemcitabine and cisplatin combination chemotherapy with double way plus radioactive seed 125I implantation was better than gemcitabine and cisplatin combination chemotherapy with double way.

Objective To investigate the CT manifestations of Meckel's diverticulum and its complications in children. Methods Retrospective analysis of Clinical and CT findings in 25 cases with pathologically proved Meckel's diverticulum. The unenhanced and contrast-enhanced CT were obtained in all patients. Results (1)The direct signs: the diverticulum cannot be shown in 5 cases; the diverticulums were found around the navel or in lower right abdomen in 20 cases. The blind-ending fluid-filled or gas-filled structures were found in 9 cases, with heterogeneous ring-enhancement. The tubercle-like structures were detected in 11 cases, which showed no enhancement in 4 cases, and homogeneous enhancement in 3 cases,and heterogeneous enhancement in 4 cases. (2) The indirect signs included intestine obstruction in 8 cases,swelling fat layer surrounding the diverticulum in 9 cases, free gas around the diverticulum in 3 cases,thickened mesentery in 8 cases, ascites in 4 cases, and intussusception due to inverted Meckel's diverticulum with "target sign" in 1 case. (3) CT classification: with diverticulitis or diverticular bleeding in 20 eases; with intestine obstruction or intussusception in 8 cases; bands-caused obstruction in 7 cases;intussusception in 1 case; with perforation in 3 cases. Conclusion Meckel's diverticulum and its complications have typical CT findings, and CT can clearly demonstrate diverticulum's shape, margin,internal components and surroundiug tissues.

Objective To study the value of breast imaging reporting and data system (BI-RADS)in Chinese breast cancer screening. Methods A total number of 3483 women participated in breast cancer screening with mammography in Hexi district in Tianjin from August to December 2009, which was organized by ministry of public health. BI-RADS assessment categories and recommendations were compared with histological findings. The precision, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Results Among 3483 screening mammography cases, 267 were almost entirely fat breast, 1245 were scauered fibroglandular, 1890 were dense and 81 extremely dense.There were 1011 patients(29.0%) with category 1, 1741 (50.0%) with category 2, 383 (11.0%) with category 3, 59 patients(1. 7%) with category 4 and 16 (0. 5%) with category 5 according to BI-RADS assessment categories. Totally, 71 women with 77 lesions were confirmed by histological examinations. There were 29 malignant and 48 benign lesions. The diagnostic precision, sensitivity, specificity of BI-RADS were 63. 6% (49/77) , 93. 1% (27/29) and 45.8% (22/48) . The general PPV of BI-RADS was 50. 9%(27/53). The PPV of categories 0, 4, 5 were 25.0% (1/4), 36. 4% (12/33) and 87. 5% (14/16). The NPV of categories 2 and3 were90.9% (10/11), 100.0% (12/12). Conclusions B1-RADS is of much value in assessing the breast malignancy. It is applicable in Chinese breast cancer screening.

Objective To evaluate the role of breast MRI in detecting the primary malignancy in patients presenting solely with axillary lymph node metastases. Methods Thirty-three patients with axillary lynph node metastases but negative findings on either physical examination or mammography underwent breast MRI to identify occult breast carcinoma. MRI of the breast was assessed according to BI-RADS criteria. The pathologic diagnosis was made according to the standard criteria by the WHO Classification of Tumor. Results Among 33 patients presenting solely with axillary metastases, 30 patients underwent modified radical mastectomy. Primary breast carcinoma was proven in 17 patients. MRI detected lesions in 16 patients, including 10 masses and 6 non-mass lesions. Size of the masses ranged from 0. 5 to 2. 6 cm (mean 1.5 cm). Six lesions were smaller than 1.5 cm in size. Non-mass lesions showed ductal enhancement in 4 cases and segmental enhancement in 2 cases. One patient with tumor detected by histopathology showed no abnormal enhancement on MRI. No tumor was found at mastectomy in the other 13 womeu, and negative MR findings were revealed in 9. Four cases with suspicious enhancement on MRI had no corresponding primary foci on pathology. Three patients didn't undergo surgical procedure. The sensitivity, specificity, and accuracy of MRI in the diagnosis of the primary malignancy were 94. 1%,69. 2%, and 83.3%, respectively. Conclusions Small size of mass and ductal or segmental enhancement of non-mass lesion were common MR features of occult malignancy. MRI showed high sensitivity and accuracy in diagnosing occult breast carcinoma. Breast MRI should be taken in search of occult malignancy in patients with axillary metastases.

Objective To evaluate the microstructural integrity of white matter (WM) in patients with amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD) using voxel-based analysis (VBA), and investigate the relationship between WM abnormalities and gray matter(GM) atrophy.Methods Thirty-three cases with aMCI, 32 cases with mild AD and 31 normal aging volunteers as control subjects were scanned on a 3.0 T MR system using diffusion tensor imaging (DTI) and three-dimensional spoiled gradient-recalled(3DSPGR) sequences. Fractional anisotropy (FA) maps and morphological images were preprocessed by SPM5 and voxel-based comparisons between the 2 patient groups and the control group were performed by t test. Results Relative to the control group, patients with aMCI showed significantly reduced FA value in bilateral frontal, temporal and left occipital WM, left anterior part of cingulum, left inferior parietal lobule, and the W M adjacent to the triangular part of the right lateral ventricle(k≥20 voxels).In mild AD,significantly reduced FA value was found in bilateral hippocampal,inferior parietal lobular,frontal,temporal,and occipital WM,bilateral corpus callosum,anterior part of cingulums,the WM adjacent to the triaangular part of the bilateral lateral ventricles,left temporal stem,left thalamus,right precuneus(k≥20 voxels).Significantly reduced GM volume was found in left hippocampus,parahippocampal gyrus,lingual gyrus and superior temporal gyrus,bilateral insulae and middle temporal gyri in aMCl group whencompared with control group(k≥50 voxels).In mild AD,significantly reduced GM volume was found in bilateral hippoeampi,parahippocampal gyri,amygdalae,thalami,temporal,parietal,frontal,occipital cortex(k≥50 voxels).The pattern of areas with reduced FA differs;from that of the GM volumetric reduction.No areas with significantlv reduced FA was detected in aMCl compared with mild AD. There was no significant correlation between FA value of WM in patient groups and Mini-Mental State Examination(MMSE)scores.Conclusions Voxel-based MRI DTI analysis of whole brain white matter can objectively reveal widespread white matter abnormalities in early-stage AD.The difierence between WM FA reduction pattern and GM volumetric reduction pattern indicates that the pathological WM changes in earlyslage AD were caused by multiple mechanisms. FA did not vary significantly in patients pr0gressing from aMCI to mild AD and can hardly reflect the severitv of cognitive function damage in these patients.

Objective To investigate the changes of brain volumes in neuromyelitis optica (NMO)patients using voxel-based morphometry (VBM) method, and preliminarily explore the pattern of cerebral anatomical impairment. Methods Twenty-three clinically defined NMO patients and 15 gender and age matched healthy volunteers underwent 3-dimensional (3D) fast spoiled gradient echo (FSPGR) sequence scanning on 3.0 Tesla MR systen. Raw data was processed and analyzed using statistical parametric mapping (SPM) 5. Whole brain volumes included grey matter volume (GMV), white matter volume (WMV), total intracranial volume (TIV), grey matter fraction (GMF), white matter fraction (WMF),brain tissue fraction (BTF) and regional brain volumes between the two groups were compared by independent samples t-test and an Pearson were performed to compare the regional brain volumes and the ages. Results GMV of NMO group[(610. 2 ± 55.0) ml] was significantly decreased comparing to healthy control group[(657. 2 ± 36. 3) ml] (t = - 2. 915, P ＜ 0. 05). The age of NMO patients [(40 ± 9) years old] showed negative correlation with GMF [(42. 5 ± 2. 6) %] (r = - 0. 673, P ＜ 0. 05). Regional brain volume analysis showed decreased GMV in left insula and bilateral posterior cingutates in NMO patients,while decreased WMV was found in left frontal and left parietal white matter. Conclusion VBM could detect brain volume changes sensitively. Total grey matter volume in NMO patients was decreased comparing to HC group. Regional grey matter atrophy in NMO patients occurred in left insular and bilateral posterior cingutates, regional white matter atrophy occurred in left frontal and left parietal lobe.

Objective To explore changes of gray matter volume in patients with obsessivecompulsive disorder (OCD) in Chinese Han population using optimized voxel-based morphometry (VBM) ,and investigate its relationship with clinical symptoms. Methods Twenty patients with OCD and 20 age,sex and handedness matched healthy controls were scanned using 3D-T1 images on a 3.0 T MR system. The high resolution T1WI was preprocessed according to the optimized VBM protocol in Statistical Parametric Mapping (SPM5). Two-sample t test was performed to characterize the differences of the gray matter volume (GMV) between the OCD patients and healthy controls, and the correlations between the GMV and symptom severity and cumulative illness duration were examined using Pearson correlation in SPSS 16. 0, respectively.Results Compared to controls, OCD patients demonstrated increased GMV in left thalamus, right thalamus and left cerebellum after false discovery rate (FDR) correction. No areas of significantly decreased GMV was observed in OCD patients in relative to healthy controls. The mean eigenvalue ranged from 0. 5782 to 0. 889 representing the left thalamus volume of OCD patients was 0. 6813 ± 0. 0718, and that ranged from 0. 5546 to 0. 9062 was 0. 6869 ± 0. 0808 tor right thalamus. The mean eigenvalues were positively correlated in bilateral thalamus (r = 0. 94, P ＜ 0. 01). Conclusion Using optimized VBM, the current research indicates that the pathophysiology of OCD is associated with GMV abnormalities not only in corticostriato-thalamo-cortical (CSTC) circuit, but also in the cerebellum.