良恶性前列腺疾病肿瘤血管形成的MR灌注加权成像评价

Objective: To explore the application of MR perfusion-weighted imaging (PWI) in the benign and malignant prostate diseases, and evaluate the correlations of PWI features with vascular endothelial growth factor (VEGF) and microvessel density (MVD). Methods: Seventy-four consecutive patients who were diagnosed clinically for the prostate diseases, including forty-four cases with benign prostate hyperplasia and thirty cases with prostatic cancer proved pathologically, were examined by PWI. MVD and VEGF were stained with immunohistochemical methods. Some parameters of PWI, including the steepest slope of signal intensity-time curve (SSmax) and the change in relaxation rate (△R2* peak) at lesions, were analyzed.Correlation analysis was used to determine the relationship between the results of PWI and immunohistochemistry. Results:(1) In the benign prostate hyperplasia (BPH), SSmax and △R2* peak of perfusion curve were 34.2 2.9 and 1.49±0.11,respectively; however, in the prostatic cancer (Pca), they were 58.6±4.8 and 3.18 0.49 respectively; there were statistical differences (t = 2.16 and 2.31, P ＜ 0.05). (2) The VEGF and MVD expressions of thirty Pca patients were significantly higher than those of forty-four BPH patients (X2 = 28.64, P＜0.01; t = 21.2, P＜0.01). MVD expressions of Pca and BPH groups showed positive associations with VEGF expressions (P＜0.01). On MR perfusion-weighted imaging, SSmax and △R2* peak showed associations with MVD and VEGF expressions (P＜0.01). Conclusion: On MR perfusion-weighted imaging, SSmax and △R2* peak can reflect MVD and VEGF expression levels in the benign and malignant prostate diseases and might be implied the tumor angiogenesis so as to distinguish benign from malignant and provide the important information for the surgeon to diagnose and treat the prostatic diseases.     

Relationship of pre-surgery metabolic and physiological MR imaging parameters to survival for patients with untreated GBM

Glioblastoma Multiforme (GBM) are heterogeneous lesions, both in terms of their appearance on anatomic images and their response to therapy. The goal of this study was to evaluate the prognostic value of parameters derived from physiological and metabolic images of these lesions. Fifty-six patients with GBM were scanned immediately before surgical resection using conventional anatomical MR imaging and, where possible, perfusion-weighted imaging, diffusion-weighted imaging, and proton MR spectroscopic imaging. The median survival time was 517 days, with 15 patients censored. Absolute anatomic lesion volumes were not associated with survival but patients for whom the combined volume of contrast enhancement and necrosis was a large percentage of the T2 hyperintense lesion had relatively poor survival. Other volumetric parameters linked with less favorable survival were the volume of the region with elevated choline to N-acetylaspartate index (CNI) and the volume within the T2 lesion that had apparent diffusion coefficient (ADC) less than 1.5 times that in white matter. Intensity parameters associated with survival were the maximum and the sum of levels of lactate and of lipid within the CNI lesion, as well as the magnitude of the 10th percentile of the normalized ADC within the contrast-enhancing lesion. Patients whose imaging parameters indicating that lesions with a relatively large percentage with breakdown of the blood brain barrier or necrosis, large regions with abnormal metabolism or areas with restricted diffusion have relatively poor survival. These parameters may provide useful information for predicting outcome and for the stratification of patients into high or low risk groups for clinical trials.     

磁共振DWI及灌注加权成像对不同时期脑梗死临床诊断的应用价值研究

目的分析磁共振DWI及灌注加权成像对不同时期脑梗死临床诊断的应用价值。方法回顾分析本院2017年1月至2019年5月收治的112例脑梗死患者的临床资料;对患者所得图像进行分析,对比不同时期梗死区与健侧对照区ADC值,PWI各灌注参数(rCBV、rCBF、MTT、TTP)表现,以及DWI、PWI在不同分期脑梗死中表现关系。结果不同时期梗死区与健侧对照区ADC值比较差异有统计学意义(P<0.05);在超急性期25例患者中,rCBV、rCBF降低,MTT、TTP升高;急性期44例患者中以rCBV、rCBF降低, MTT、 TTP升高为主;亚急性期33例患者中以rCBV、rCBF正常,MTT、TTP升高为主;慢性期10例患者中均为rCBV、rCBF降低,1例患者MTT、TTP表现为升高,其余为降低。超急性期患者68.00%(17/25)为DWIPEI;亚急性期78.78%(26/33)为DWI=PWI;慢性期患者均表现为DWI=PWI。结论 PWI、DWI序列联合诊断可识别早期梗死病灶,并对患者血流灌注情况进行评价,可鉴别半暗带缺血区,并为不同时期临床诊断和梗死分期提供可靠影像学参考依据。     

Combined diffusion- and perfusion-weighted imaging: a new way for the assessment of hemispheric transient ischemic attack patients

Abnormalities in diffusion-weighted and perfusion-weighted magnetic resonance images not only occur in stroke patients but also in transient ischemic attack patients. We found magnetic resonance images were abnormal in 28 patients (68%): 15 had diffusion-weighted imaging abnormalities, 7 had both diffusion-weighted imaging and perfusion-weighted imaging defects and 6 had an isolated perfusion-weighted imaging abnormality. Patients with shorter onset to magnetic resonance imaging, large artery atherothrombosis, coronary artery disease, hyperlipidemia and hemiparesis were more likely to show perfusion-weighted imaging abnormalities. Compared with patients who had a good prognosis, in poor prognosis patients, the relative cerebral blood flow and relative cerebral blood volume was significantly higher. The data suggest that transient ischemic attack patients are more likely to have a poor prognosis when white matter of the symptomatic side shows hyperperfusion within 24 h of symptom onset; however, patients are more likely to have a good prognosis when white matter of the symptomatic side shows hypoperfusion.     

Performance assessment of pulse wave imaging using conventional ultrasound in canine aortas ex vivo and normal human arteries in vivo

The propagation behavior of the arterial pulse wave may provide valuable diagnostic information for cardiovascular pathology. pulse wave imaging (PWI) is a noninvasive, ultrasound imaging-based technique capable of mapping multiple wall motion waveforms along a short arterial segment over a single cardiac cycle, allowing for the regional pulse wave velocity (PWV) and propagation uniformity to be evaluated. The purpose of this study was to improve the clinical utility of PWI using a conventional ultrasound system. The tradeoff between PWI spatial and temporal resolution was evaluated using an ex vivo canine aorta (n = 2) setup to assess the effects of varying image acquisition and signal processing parameters on the measurement of the PWV and the pulse wave propagation uniformity r². PWI was also performed on the carotid arteries and abdominal aortas of 10 healthy volunteers (24.8 ± 3.3 y.o.) to determine the waveform tracking feature that would yield the most precise PWV measurements and highest r² values in vivo. The ex vivo results indicated that the highest precision for measuring PWVs ∼2.5–3.5 m/s was achieved using 24–48 scan lines within a 38 mm image plane width (i.e. 0.63–1.26 lines/mm). The in vivo results indicated that tracking the 50% upstroke of the waveform would consistently yield the most precise PWV measurements and minimize the error in the propagation uniformity measurement. Such findings may help establish the optimal image acquisition and signal processing parameters that may improve the reliability of PWI as a clinical measurement tool.     

MR弥散张量成像和灌注成像对鼠脑C6胶质瘤模型的量化分析

目的：探讨 MR 弥散张量成像和灌注成像在大鼠 C6脑胶质瘤模型诊断中的意义。方法：构建大鼠 C6脑胶质瘤模型,选择肿瘤最大层面分别获取 Ktrans、Kep、Ve、MD 和 FA 图。结果：Ktrans、Kep、Ve、MD 和 FA 值在肿瘤区域、坏死区域和正常脑组织均存在统计学差异（P〈0.001）。 Ktrans 值与 Kep 值呈高度正相关（肿瘤区域：0.932,P〈0.001;坏死区域：0.921,P〈0.001;正常组织：0.071,P ＝0.676）;扣除 Ktrans值的影响,Kep 值和 Ve 值呈负相关（肿瘤区域：-0.602,P〈0.001;坏死区域：-0.617,P〈0.001;正常组织：0.084,P＝0.626）;扣除 Kep 值的影响,Ktrans 值和 Ve 值呈正相关（肿瘤区域：0.406,P ＝0.014;坏死区域：0.582,P〈0.001;正常组织：0.275,P＝0.105）。 FA 值和 MD 值呈现负相关（肿瘤区域：-0.898,P〈0.001;坏死区域：-0.782,P〈0.001;正常组织：-0.478,P＝0.003）。结论：MR 弥散张量成像和灌注成像有助于胶质瘤模型中肿瘤区域、坏死区域和正常脑组织的鉴别。     

PWI对胶质瘤术后复发与放射性脑损伤的鉴别诊断价值

脑胶质瘤术后放疗后的病人,一旦脑内出现新的异常强化灶时常需要考虑肿瘤复发或放射性脑损伤,常规磁共振检查较难鉴别。磁共振灌注加权成像（PWI）是反映组织微观血流动力学信息的一项新技术,可对二者鉴别提供更多信息,本文就近年PWI在诊断肿瘤复发及放射性脑损伤中的应用加以综述。     

前列地尔注射液对急性脑梗死患者MR脑灌注水平的影响

目的 观察前列地尔注射液对急性脑梗死(acute cerebral infarction,ACI)患者的临床疗效及对患者脑灌注水平的影响.方法 83例ACI患者随机分为前列地尔组(n=43)和常规治疗组(n=40)及健康对照组(n=40).采用全脑磁共振灌注成像(PWI),观察患者在治疗后48 h,7d的脑灌注水平,并在治疗后7d进行临床疗效的判定.结果 两组患者治疗7d后,前列地尔组在相对脑血流量(rCBF),相对脑血容积(rcBV),均较常规治疗组显著增加(P＜0.01).结论 前列地尔注射液可能通过改善脑灌注水平发挥治疗ACI的有效性.     

大鼠肝肿瘤放疗及酒精治疗MRI动态灌注表现

目的 研究大鼠肝肿瘤放疗及无水酒精注射治疗后MRI动态灌注表现及其半定量指标最大相对信号强度增减率(MRSI)与免疫组织化学指标增殖细胞核抗原(PCNA)、血管内皮细胞生成因子(VEGF)及CD34的相关性. 材料与方法 (1)选取45只肝肿瘤大鼠,随机分成放疗组、酒精注射组及未治疗组,每组15只,分1天、3天、7天共3个时间点观察;(2)每组大鼠每个时间点均采集MRI动态灌注图像, 后处理得到灌注曲线及MRSI;(3)MRI检查后取标本送病理及免疫组织化学(PCNA,VEGF,CD34)检查;(4)将免疫组织化学结果与MRI图像对照分析. 结果 (1)放疗组PCNA染色增殖指数较未治疗组下降, VEGF染色阳性率稍减低, CD34染色阳性表达的微血管数减少及MRSI下降; 且MRSI与PCNA染色增殖指数、CD34染色阳性表达微血管数及VEGF表达阳性率呈正相关.(2)酒精注射组PCNA染色增殖指数较未治疗组下降明显,并见CD34染色阳性表达的微血管数显著减少,VEGF染色阳性率及MRSI明显减低;MRSI与PCNA、VEGF及CD34呈正相关. 结论 放疗及酒精注射治疗对大鼠肝肿瘤新生血管有抑制作用,MRI动态增强能反映肿瘤的血供情况.