Magneticaly labeled stem cells and magnetic resonance imaging(MRI) technology is an effective tracking method in vivo study, which has high spatial-temporal resolution. Gadolinium, which shows positive T1 signals and iron oxide showing negative T2 signals are the two often used contrast agents. The latter also include superparamagnetic iron oxide particle and ultrasmall superparamagnetic iron oxide particle. Transfection agents, e.g. poly-L-lysine and protamine sulfate，can enhance magnetical nanoparticles labeling stem cells. The biological characteristics of labeled stem cells did not seem to be altered. MRI can detect the labeled stem cells’ signals and also can track changes of signal in intensity and size with time past. In conclusion, MRI tracking magneticaly labeled stem cells represents a method for noninvasivly monitoring the existence and migration of engrafts.
目的 探讨常规注射速率下单倍剂量对比剂在颈部三维对比增强磁共振血管成像（3D-CEMRA）中的可行性及临床应用价值。 方法 2011年8月－11月，连续纳入30例临床怀疑颈动脉或椎动脉狭窄并要求颈部磁共振血管成像检查的患者，随机分成A、B两组（每组各15例）。使用西门子Magnetom Avanto 1.5 T磁共振成像仪及其配备的颈部线圈和头部线圈进行CEMRA成像。A组使用双倍剂量对比剂（0.2 mmol/kg），B组使用单倍剂量对比剂（0.1 mmol/kg）。用三维快速小角度激发序列进行颈部血管成像。由2位有丰富经验的高年资医生对两组原始图像的信噪比以及最大密度投影（MIP）图像的质量进行评价，并对结果进行统计学分析和处理。 结果 A、B两组的所颈动脉信噪比分别为189.95 ± 71.31、175.07 ± 68.61，差异无统计学意义（t=?0.566，P=0.576）；所得的MIP图像质量均达到优良，差异无统计意义（χ2=0.180，P=0.671）。 结论 与双倍剂量相比，单倍剂量对比剂获得颈部血管的图像清晰，能够满足临床诊断要求。
【摘要】 目的 在实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)模型中,比较常规T2加权成像(T2weighted imaging,T2WI)、钆二乙三胺五醋酸(gadoliniumdiethylenetriamine pentaacetic acid,GdDTPA)和超顺磁性氧化铁(superparamagnetic iron oxide,SPIO)增强图像之间的差异,探讨巨噬细胞在多发性硬化(multiple sclerosis,MS)炎性活动病灶中的细胞学标志。方法 在EAE模型临床症状的亚临床期、初发期、高峰期,13只复发缓解(relapsingremitting,RR)EAE大鼠模型组和13只正常对照组大鼠在注入对比剂之前均行常规T2WI扫描,接着分别在其尾静脉注入GdDTPA后5 min行T1加权成像(T1weighted imaging,T1WI),再注入SPIO,24 h后行T2WI扫描。扫描完毕后立即处死大鼠取脑,行脑组织切片的ED1免疫组织化学染色和Prussian blue染色。结果 EAE模型组大鼠在第11天出现临床症状(初发期),第14天达到高峰期;MRI检查:SPIO增强图像对EAE病灶的显示较常规T2WI和GdDTPA增强图像好。病理学检查:ED1染色,在SPIO显示为低信号的区域内出现了炎症细胞(以巨噬细胞为主)浸润;Prussian blue染色示病灶内巨噬细胞胞质内出现了蓝染颗粒,沉积部位与T2WI上低信号区对应。对照组大鼠均无异常。结论 SPIO较GdDTPA更好地显示EAE模型中炎性活动性病灶内血管周围以巨噬细胞为主的浸润。
目的:探讨64层螺旋CT冠状动脉成像(64-slice CTA)检查中护理工作的重要性及获得最佳图像的影响因素。材料与方法:对462例行64-slice CTA检查的患者进行有效的护理措施和细致的前期准备工作。结果:462例检查者中96%的病例达到诊断标准。结论:经过细致准备和护理,可以提高图像质量和冠脉疾病的诊断率。
ObjectiveTo assess the image quality and radiation dose of gemstone CT coronary angiography (CCTA) with low tube voltage and low concentration contrast medium. MethodsSixty-nine patients who underwent CCTA from January to March 2014 were randomly divided into group A and B. CCTA was performed in thirty-four patients in group A with tube voltage of 100 kV and concentration of contrast medium of 300 mgI/mL. And thirty-five patients in group B underwent CCTA with 120 kV and 370 mgI/mL. According to upgrading American Heart Association standard all segments and all vessels were evaluated. We measured the CT value of ascending aortic root, left main coronary artery, and the initial segment of left anterior descending branch, left circumflex, right coronary artery, and also adjacent tissues. Besides, we recorded CT dose volume index (CTDIvol) and the dose length product (DLP) and calculated effective radiation dose. ResultsThe image quality scores were not significantly different between two groups (P>0.05). The density in the contrast enhanced vessel lumens in group A were signifcantly higher than that in group B (P<0.05). There was no significant difference in signal to noise ratio and carrier to noise ratio between the two groups (P>0.05). Noise in group A was higher than that in group B (P<0.05). The CTDIvol and effective radiation dose in group A were significantly lower than those in group B (P<0.05). ConclusionThe combination of 100 kV with low concentration contrast medium (300 mgI/mL) still maintains the image quality, as well as significantly lowers the radiation dose and the dose of iodine.
ObjectiveTo explore the influence of different concentrations of iodinated contrast agent on image quality of galactography. MethodsBetween June 2008 and October 2009, 50 non-pregnancy and non-lactation patients with mammary papilla discharge underwent breast galactography with digital mammography. All the patients' left breasts were in group L, and right breasts were in group R. The iohexol concentration of iopamidol injection was 370 mg/mL in group L and 300 mg/mL in group R. The image quality and the evaluation of average density of the two groups was analyzed and compared. ResultsThe image quality score of group L and R was 2.8±0.2 (P>0.05). The mean density of main duct of breast axial view in two groups was (4 020.25±96.26) and (3 984.75±117.67) HU, respectively; the mean density of the lateral oblique view was (4 067.13±24.69) and (3 971.25±167.32) HU, respectively; the mean density of the lateral view was (4 058.88±52.07) and (4 034.75±67.54) HU, respectively. There was no significant difference between the two groups (P>0.05). ConclusionNo obvious difference between the two concentrations of non-ionic iodinated contrast agents (300 and 370 mg/mL) in galactography diagnosis is found.
ObjectiveTo explore the clinical value of low-dose contrast agnet in CT angiography (CTA) for head and neck by SOMATOM Definition Flash CT.MethodsSixty consecutive patients with head and neck vessel diseases examined by CTA in the head and neck were chosen from West China Hospital of Sichuan University from March to July 2015, and then were randomly divided into two groups (the experimental group: n=30, 30 mL contrast medium; the control group: n=30, 50 mL contrast medium). Imaging post processing techniques included curved plannar reconstruction, volume rendering, and maximal intensity projection. CT values of the different level of carotid arteries (aortic arch, carotid bifuracation, and M1 segment of middle cerebral artery) were measured. The artifact of the remaining contract in the jugular vein and overall quality of the image were observed by two senior doctors using double blind method.ResultsAll the patients in the two groups completed CTA for head and neck successfully. The image qualities of the two groups satisfid clinical diagnostic requirements, and there was no difference in the image qualities between the two groups (P>0.05). The evaluation of venous pollution in the experimental group was lighter than that in the control group (P<0.05). The CT values of aortic arch, carotid bifuracation, and M1 segment of middle cerebral artery in the experimental group [(341.3±89.5), (391.0±103.7), (305.0±62.0) HU] were slightly lower than those in the control group [(437.3±83.7), (532.5±113.3), (396.6±93.1) HU], which were statistically significant (P<0.05).ConclusionLow-dose contrast in CTA for head and neck by SOMATOM Definition Flash CT can satisfy the clinical diagnostic requirements, and reduce the dose of contrast agent and venous pollution, with a good clinical value.
ObjectivesTo evaluate the association between high homocysteine (Hcy) levels and risk of contrast-induced nephropathy (CIN).MethodsCNKI, VIP, WanFang Data, PubMed, The Cochrane Library and Web of Science databases were electronically searched to collect the case-control studies on the association between Hcy and risk of CIN from inception to November 30th, 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was performed by using Stata 12.0 software.ResultsTen case-control studies involving 6 124 subjects were included. Meta-analysis showed that the high Hcy level was associated with an increased risk of CIN (OR=1.59, 95%CI 1.33 to 1.89, P<0.001), and the homocysteine level in CIN group was higher than that in non-CIN group (WMD=8.74, 95%CI 6.18 to 11.31,P<0.001).ConclusionsAccording to the current evidence, the high Hcy level is a risk factor for CIN. Due to limited quality and quantity of the included studies, more high quality studies are required to verify the above conclusion.