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1.
目的研究脑膜血管型神经梅毒的影像学特征,指导与脑梗死的鉴别诊断。方法对神经梅毒患者进行头部MRI平扫+增强、磁共振血管成像(Magnetic Resonance Angiography,MRA)、灌注加权成像(perfusion weighted imaging,PWI)和磁敏感加权成像(Susceptibility weighted imaging,SWI)检查,PWI得出4种参数:局部脑血流量(regional cerebral blood flow,rCBF)、局部脑血容量(regional cerebral blood volume,rCBV)、平均通过时间(mean transit time,MTT)、达峰时间(time to peak,TTP)。将患者病灶侧PWI 4种参数和病灶对侧参数进行对比。结果7例患者行头部MRI检查共发现责任病灶9个:2个在脑桥、1个在放射冠区、1个在丘脑、1个枕叶、2个在顶叶、1个在岛叶、1个在额叶。1个放射冠区病灶边缘有增强。6例均有血管狭窄。通过对7例神经梅毒患者行PWI检查发现,与对侧相比,责任病灶区域rCBV值[(72.47±46.51)vs.(130.68±38.92)]降低,t=4.172,P=0.002;rCBF值[(111.10±37.89)vs.(153.43±50.81)]降低,t=2.804,P=0.025。责任病灶区域MTT值、TTP值无变化(P=0.569、0.171)。结论神经梅毒患者颅内病灶的PWI表现可能具有不同于脑梗死的影像学特征。  相似文献   
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ObjectiveTo investigate imaging biomarkers of microperfusion in contrast-induced nephropathy (CIN) using contrast-enhanced ultrasound (CEUS).Materials and MethodsThe CIN model was fabricated by administering indomethacin (10 mg/kg), L-NAME (15 mg/kg), and iopamidol (10 mL/kg) to Sprague-Dawley rats. After 24 hours, CEUS was performed on CIN (n = 6) and control (n = 6) rats with sulphur hexafluoride microbubbles (SonoVue). From time-intensity curves obtained from the kidney arriving time (AT), acceleration time (AC), time to peak (TTP), and peak enhancement (PE) were measured and compared between the groups. After CEUS, the rats were sacrificed, and cell apoptosis markers were evaluated to confirm the development of CIN.ResultsAmong CEUS parameters, AT (7.8 ± 1.6 vs. 4.2 ± 0.5 s, p = 0.002), AC (4.7 ± 1.4 vs. 2.0 ± 0.4 s, p = 0.002), and TTP (12.5 ± 2.9 vs. 6.2 ± 0.6 s, p = 0.002) were significantly prolonged in the CIN group compared to controls. PE was significantly higher in the control group than in the CIN group (17.1 ± 1.9 vs. 12.2 ± 2.0 dB, p = 0.004). In kidney tissue, mRNA and protein levels of the apoptotic makers were significantly higher in the CIN group than in the control group (p = 0.003 and p = 0.002).ConclusionCEUS parameters can be used as imaging biomarkers for microperfusion in CIN. In rats with CIN, AT, AC, and TTP were significantly prolonged, while PE was significantly lower compared to controls.  相似文献   
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Dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a powerful tool for cancer diagnosis by estimation of perfusion and dispersion parameters reflecting angiogenic vascular changes. This work was aimed at identifying which vascular features are reflected by the estimated perfusion and dispersion parameters through comparison with acoustic angiography (AA). AA is a high-resolution technique that allows quantification of vascular morphology. Three-dimensional AA and 2-D DCE-US bolus acquisitions were used to monitor the growth of fibrosarcoma tumors in nine rats. AA-derived vascular properties were analyzed along with DCE-US perfusion and dispersion to investigate the differences between tumor and control and their evolution in time. AA-derived microvascular density and DCE-US perfusion exhibited good agreement, confirmed by their spatial distributions. No vascular feature was correlated with dispersion. Yet, dispersion provided better cancer classification than perfusion. We therefore hypothesize that dispersion characterizes vessels that are smaller than those visible with AA.  相似文献   
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《Alzheimer's & dementia》2019,15(9):1172-1182
IntroductionDual-biomarker positron emission tomography (PET), providing complementary information on cerebral blood flow and amyloid-β deposition, is of clinical interest for Alzheimer's disease (AD). The purpose of this study was to validate the perfusion components of early-phase 18F-florbetapir (eAV45), the 18F-AV45 delivery rate (R1), and 18F-FDG against 15O-H2O PET and assess how they change with disease severity.MethodsThis study included ten controls, 19 amnestic mild cognitive impairment, and 10 AD dementia subjects. Within-subject regional correlations between modalities, between-group regional and voxel-wise analyses of covariance per modality, and receiver operating characteristic analyses for discrimination between groups were performed.ResultsFDG standardized uptake value ratio, eAV45 (0–2 min) standardized uptake value ratio, and AV45-R1 were significantly associated with H2O PET (regional Pearson r = 0.54–0.82, 0.70–0.94, and 0.65–0.92, respectively; P < .001). All modalities confirmed reduced cerebral blood flow in the posterior cingulate of patients with amnestic mild cognitive impairment and AD dementia, which was associated with lower cognition (r = 0.36–0.65, P < .025) and could discriminate between patient and control groups (area under the curve > 0.80). However, eAV45 was less sensitive to reflect the disease severity than AV45-R1 or FDG.DiscussionR1 is preferable over eAV45 for accurate representation of brain perfusion in dual-biomarker PET for AD.  相似文献   
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The current standard approach to manage circulatory insufficiency is inappropriately simple and clear: respond to low blood pressure to achieve higher values. However, the evidence for this is limited affecting all steps within the process: assessment, decision making, therapeutic options, and treatment effects. We have to overcome the ‘one size fits all’ approach and respect the dynamic physiologic transition from fetal to neonatal life in the context of complex underlying conditions. Caregivers need to individualize their approaches to individual circumstances. This paper will review various clinical scenarios, including managing transitional low blood pressure, to circulatory impairment involving different pathologies such as hypoxia-ischemia and sepsis. We will highlight the current evidence and set potential goals for future development in these areas. We hope to encourage caregivers to question the current standards and to support urgently needed research in this overlooked but crucial field of neonatal intensive care.  相似文献   
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目的比较单光子发射型计算机断层(SPECT)心肌灌注显像和冠脉CT血管成像(CCTA)对冠心病心肌缺血的诊断价值。方法选取2017年6月-2018年10月因冠心病或疑似冠心病而进行冠脉造影(CAG)、CCTA和SPECT心肌灌注显像患者34例为研究对象,以CAG为金标准,评价CCTA和SPECT心肌灌注显像对冠心病心肌缺血的诊断效能。结果CCTA检出患者24例(70.59%),检出主要冠脉50支(49.02%);SPECT心肌灌注显像检出可逆性缺损者20例(冠脉36支)。以CAG为金标准,根据患者例数,CCTA诊断灵敏度95.65%,特异度81.82%,SPECT心肌灌注显像诊断灵敏度82.61%,特异度90.91%;根据冠脉支数,CCTA诊断灵敏度88.37%,特异度79.66%,SPECT心肌灌注显像诊断灵敏度72.09%,特异度91.52%。结论CCTA诊断冠心病心肌缺血具有较高的灵敏度和阴性预测值,SPECT心肌灌注显像诊断冠心病心肌缺血具有较高特异性和阳性预测值,两者互为补充,综合判断可提高诊断准确性。  相似文献   
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目的探讨18F-FDG PET/CT联合320容积CT双入口灌注成像(DI-CTP)肺动脉灌注指数(PPI)对单发性肺结节的鉴别诊断价值。方法搜集经病理证实40例单发性肺结节患者的18F-FDG PET/CT及320排CT灌注成像影像资料(恶性结节24例、良性结节16例),PET/CT以结节18F-FDG摄取值SUV≥2.5为诊断恶性结节阈值,18F-FDG PET/CT联合PPI则在SUV≥2.5诊断阈值的基础上综合PPI<50%判定,并分析SUV与PP均值在良恶性结节间差异性及相关性。结果PET/CT联合PPI正确诊断38例,其中恶性结节22例、良性结节16例,误诊2例。18F-FDG PET/CT联合PPI诊断肺单发结节的敏感性91.6%,特异性100%,准确性95.0%;18F-PDG摄取值SUV在良、恶性结间差异无统计学意义(t=1.66,P>0.05),而PPI均值在良、恶性结节间差异有统计学意义(t=-3.14,P<0.01);SUV与PPI间相关性无统计学意义(r=0.20,P>0.05)。结论18F-FDG PET/CT联合PPI可以提高诊断肺单发肺结节敏感性、特异性和准确性,减少误诊率。  相似文献   
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