Twelve healthy volunteers underwent ECG-triggered non-contrast-enhanced magnetic resonance venography(NCE-MRV)of lower extremities on a 1.5T MR scanner.Image quality was assessed quantitatively and qualitatively with a 17-segment model.ECG-triggered (NCE-MRV) was successfully performed in all patients.Mean signal to noise ratio and contrast to noise ratio of lower extremities were 66 ± 23 and 53 ± 22 respectively.Excellent and good image qualities were achieved in 62％ and 31％ of all segments respectively without non-evaluable segment.Thus ECG-triggered NCE-MRV of lower extremities is feasible with reliable image quality.

Objective To evaluate the feasibility of 320-row volume CT myocardial perfusion imaging (CT-MPI) in detecting myocardial perfusion defect.MethodsFourteen patients with positive single-positron emission computed tomography myocardial perfusion imaging (SPECT-MPI)findings underwent both rest and adenosine stress 320-row volume CT-MPI.Rest and stress CT perfusion images were analyzed by employing dedicated software in 320-row CT workstation.Both SPECT-MPI and CT-MPI were evaluated for fixed and reversible perfusion defects using a 16-segment model (apex was excluded).The sensitivity,specificity of 320-row volume CT-MPI in detecting myocardial perfusion defect were evaluated by taking SPECT-MPI as a reference standard.ResultsBoth rest and stress 320-row volume CT-MPI were successfully performed in all patients.Thirty nine segments with fixed or reversible perfusion defects in all patients were depicted by SPECT-MPI,while 34 perfusion defects in 12 patients were identified by CT-MPI.The sensitivity,specificity of 320-row volume CT-MPI for detection of perfusion defects were 87.2％(34/39),91.4％ ( 169/185 ),respectively.Conclusion320-row volume CT-MPI has high sensitivity and specificity for detection of myocardial perfusion defects.

Objective To verify the feasibility of eryoablation on rabbit brain tumor under interventional MRI guidance.Methods The procedures were performed under general anaesthesia.Twenty-two New Zealand white rabbit'S brains were inoculated with VX,tumor tissue through cranial holes. MR-guided cryoablation were conducted as preliminary experiment when diameter of brain tumor grew up to 0.8 cm in size.Cryoablation lasted two cycles of 5 minutes freezing, in 2 rabbits.and of 10 minutes freezing in another 2 rabbits.After procedure and MR scanning.rabbits were executed.Specimens of rabbit'S brain showed complete necrosis pathologically after cryoablation of cycles of 10 minutes freezing.The optimal parameters of eryoablation were defined.Except for the two rabbits that died of infection,the other 16 rabbits were divided into control group and therapeutic group.According to the optimal parameters of cryoablation,cryoablation of 10 minutes freezing were performed for rabbit brain tumors in therapeutic group.Venous injeetion of 20%mannitol and subcutaneous injection of dexamethasone were used for dehydration.None of rabbit brain tumors in the control group were treated.After cryoablation,MRI scanning Was performed immediately,7 days later,14 days later and 60 days later,to observe the ablative area and the pathologic changes.The survival time wag recorded.Resuits Brain tumors could be found in all New Zealand white rabbits after inoculation except two died of inflammation.The maximum diameter of brain tumors Was from 0.7 to 1.0 elEL The tumors showed slight low signal on T1WI and slight high signal on T2WI as well as comrast enhancement after injection of Gd-DTPA.Pathologically coagulative necrosis were observed after cryoablation immediately,7 days and 14 days later,and liquefactive necrosis was found 60 days later.The correlation between MRI and pathologic appearance of tmnors are consistent.The therapeutic area ranged from 1.0 to 1.5 em.,The maximium diameter of ice ball ranged from 1.5 to 2.0 cm Conclusion CiToablation for brain tumor iS a safe and feasible therapy.

Background and Objectives: Chronic periodontitis can lead to alveolar bone resorption and eventually tooth loss. Stem cells from exfoliated deciduous teeth (SHED) are appropriate bone regeneration seed cells. To track the survival, migration, and differentiation of the transplanted SHED, we used super paramagnetic iron oxide particles (SPIO) Molday ION Rhodamine-B (MIRB) to label and monitor the transplanted cells while repairing periodontal bone defects. Methods: and Results: We determined an appropriate dose of MIRB for labeling SHED by examining the growth and osteogenic differentiation of labeled SHED. Finally, SHED was labeled with 25 μg Fe/ml MIRB before being transplanted into rats. Magnetic resonance imaging was used to track SHED survival and migration in vivo due to a low-intensity signal artifact caused by MIRB. HE and immunohistochemical analyses revealed that both MIRB-labeled and unlabeled SHED could promote periodontal bone regeneration. The colocalization of hNUC and MIRB demonstrated that SHED transplanted into rats could survive in vivo. Furthermore, some MIRB-positive cells expressed the osteoblast and osteocyte markers OCN and DMP1, respectively. Enzyme-linked immunosorbent assay revealed that SHED could secrete protein factors, such as IGF-1, OCN, ALP, IL-4, VEGF, and bFGF, which promote bone regeneration. Immunofluorescence staining revealed that the transplanted SHED was surrounded by a large number of host-derived Runx2- and Col II-positive cells that played important roles in the bone healing process. Conclusions SHED could promote periodontal bone regeneration in rats, and the survival of SHED could be tracked in vivo by labeling them with MIRB. SHED are likely to promote bone healing through both direct differentiation and paracrine mechanisms.

OBJECTIVETo explore the diagnostic value of magnetic resonance (MR) diffusion tensor imaging (DTI) in detecting brain white matter (WM) damage of patients with delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) and evaluating their cognitive dysfunction.

METHODSThirteen patients with DEACMP and thirteen age- and sex-matched volunteers underwent DTI using 1.5T MR scanner. FA and ADC values of 16 WM regions of interests (ROIs) were measured on DTI by two experienced radiologists independently with double blind methods, cognitive functions were evaluated by another experienced neurologist blinded to patient's medical history using the Montreal cognitive assessment (MoCA). ADC and FA values in DEACMP patients, and their correlations with cognitive dysfunction were analyzed.

RESULTSADC values of DEACMP patients increased significantly in all ROIs (P < 0.05) in comparison with the corresponding ROIs of healthy controls, whereas FA values were significantly decreased in all ROIs (P < 0.05) in comparison with that in controls except the bilateral optic radiations, anterior and posterior internal capsules. MoCA scores were positively correlated with FA values of bilateral lower frontal (r(L) = 0.736, P = 0.011; r(R) = 0.762, P = 0.003) lobe, temporal lobe (r(L) = 0.605, P = 0.016; r(R) = 0.559, P = 0.021) and total average WM (r(A) = 0.688, P = 0.001), however it inversely correlated with ADC values of bilateral lower frontal WM (r(L) = -0.674, P = 0.007; r(R) = -0.681, P = 0.019).

CONCLUSIONDTI can quantitatively reveal WM microstructure damage of DEACMP patients, indicate the severity of cognitive dysfunctions, and provide important information for pathogenesis and pathological study for DEACMP.

Brain ; pathology ; Brain Diseases ; diagnosis ; etiology ; Carbon Monoxide Poisoning ; complications ; Cognition ; Cognition Disorders ; Diffusion Magnetic Resonance Imaging ; Diffusion Tensor Imaging ; Double-Blind Method ; Humans ; White Matter ; pathology

Abstract: Objective To investigate the impacts of blood pressure (BP) variability on neurological deterioration in patients with acute ischemic stroke after intravenous thrombolysis (IVT). Methods The clinical data of 134 patients after IVT in Department of Neurology, Affiliated jinhua Hospital, Zhejiang University School of Medicine from January 2020 to September 2020 were retrospectively analyzed, including hour-to-hour BP measurements. BP variability profiles, including average squared difference between successive measurements (sv), standard deviation (sd) were calculated. Early neurological deterioration (END) was defined as the National Institutes of Health Stroke Scale > 4 or death within 24 hour after IVT. The binary logistic-regression model was performed to determine the independent risk factors of END. Results Among134 patients, with mean age 67 year and median NIHSS 5,11 (8. 2%) patients achieved END. Compared with non-END group, END group has higher systolic BP sd (18 vs 14, t=-2.567,P=0.011),systolic BP sv (22 vs 17, t= -1.988, P=0.049). diastolic BP sd (13 vs 9.8.t= -2.431, P=0.016). Systolic BP sd, systolic BP sv and diastolic BP sd were related to the occurring of END independently. Conclusions SP variability is negatively associated with neurological deterioration occurring within 24h following ischemic stroke with intravenous thrombolysis.