Three-dimensional arterial spin labeling and diffusion kurtosis imaging in evaluating perfusion and infarct area size in acute cerebral ischemia

BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.

Reliability of Three Dimentional Pseudo-continuous Arterial Spin Labeling:A Volumetric Cerebral Perfusion Imaging with Different Post-labeling Time and Functional State in Health Adults

Objective To evaluate the reliability of three dimensional spiral fast spin echo pseudo-continuous arterial spin labeling(3 D pc-ASL) in measuring cerebral blood flow(CBF) with different post-labeling delay time(PLD) in the resting state and the right finger taping state.Methods 3 D pc-ASL and three dimensional T1-weighted fast spoiled gradient recalled echo(3 D T1-FSPGR) sequence were applied to eight healthy subjects twice at the same time each day for one week interval. ASL data acquisition was performed with post-labeling delay time(PLD) 1.5 seconds and 2.0 seconds in the resting state and the right finger taping state respectively. CBF mapping was calculated and CBF value of both the gray matter(GM) and white matter(WM) was automatically extracted. The reliability was evaluated using the intraclass correlation coefficient(ICC) and Bland and Altman plot.Results ICC of the GM(0.84) and WM(0.92) was lower at PLD 1.5 seconds than that(GM, 0.88; WM, 0.94) at PLD 2.0 seconds in the resting state, and ICC of GM(0.88) was higher in the right finger taping state than that in the resting state at PLD 1.5 seconds. ICC of the GM and WM was 0.71 and 0.78 for PLD 1.5 seconds and PLD 2.0 seconds in the resting state at the first scan, and ICC of the GM and WM was 0.83 and 0.79 at the second scan, respectively.Conclusion This work demonstrated that 3 D pc-ASL might be a reliable imaging technique to measure CBF over the whole brain at different PLD in the resting state or controlled state.

Arterial spin labeling in neuroimaging

Arterial spin labeling(ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer.As compared with other perfusion techniques,ASL offers several advantages and is now available for routine clinical practice in many institutions.Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies.Recent technical advances have increased its sensitivity and also extended its potential applications.This review focuses on some basic knowledge of ASL perfusion,emerging techniques and clinical applications in neuroimaging.

Three-dimensional-arterial spin labeling perfusion correlation with diabetes-associated cognitive dysfunction and vascular endothelial growth factor in type 2 diabetes mellitus rat

BACKGROUND Type 2 diabetes mellitus(T2DM) has been strongly associated with an increased risk of developing cognitive dysfunction and dementia.The mechanisms of diabetes-associated cognitive dysfunction(DACD) have not been fully elucidated to date.Some studies proved lower cerebral blood flow(CBF) in the hippocampus was associated with poor executive function and memory in T2DM.Increasing evidence showed that diabetes leads to abnormal vascular endothelial growth factor(VEGF) expression and CBF changes in humans and animal models.In this study,we hypothesized that DACD was correlated with CBF alteration as measured by three-dimensional(3D) arterial spin labeling(3D-ASL) and VEGF expression in the hippocampus.AIM To assess the correlation between CBF(measured by 3D-ASL and VEGF expression) and DACD in a rat model of T2DM.METHODS Forty Sprague-Dawley male rats were divided into control and T2DM groups.The T2DM group was established by feeding rats a high-fat diet and glucose to induce impaired glucose tolerance and then injecting them with streptozotocin to induce T2DM.Cognitive function was assessed using the Morris water maze experiment.The CBF changes were measured by 3D-ASL magnetic resonance imaging.VEGF expression was determined using immunofluorescence.RESULTS The escape latency time significantly reduced 15 wk after streptozotocin injection in the T2DM group.The total distance traveled was longer in the T2DM group;also,the platform was crossed fewer times.The percentage of distance in the target zone significantly decreased.CBF decreased in the bilateral hippocampus in the T2DM group.No difference was found between the right CBF value and the left CBF value in the T2DM group.The VEGF expression level in the hippocampus was lower in the T2DM group and correlated with the CBF value.The escape latency negatively correlated with the CBF value.The number of rats crossing the platform positively correlated with the CBF value.CONCLUSION Low CBF in the hippocampus and decreased VEGF expression might be crucial in DACD.CBF measured by 3D-ASL might serve as a noninvasive imaging biomarker for cognitive impairment associated with T2DM.

Advances in arterial spin labeled cerebral perfusion imaging in cerebrovascular diseases

Cerebrovascular disease is a disease with high morbidity,disability and mortality rates,which seri-ously affects the daily life of patients and is a heavy burden on families and society.Arterial spin labeling(ASL)is a magnetic resonance imaging(MRI)technology that uses the magnetic labeling of hydrogen atoms in arterial blood as tracers to noninvasively evaluate brain blood flow.ASL does not require injection of an exogenous contrast agent,and has the advantages of no radiation,simplicity and low cost.In cerebrovascular diseases,ASL can evaluate the collateral cerebrovascular circulation and abnormal perfusion of brain tissue,which can provide a reliable basis for early diagnosis and clinical decision-making.This study reviewed ASL and its application in the diagnosis,treatment and prognosis of cerebrovascular diseases.

Hyperperfusion of Multiple Sclerosis Plaques Characterized by 3D FSE Arterial Spin Labelling

MULTIPLE sclerosis （MS） is a common inflammatory demyelinating disorder of central nervous system, and the disease burder could be well evaluated by conven-tional magnetic resonance imaging （MRI）,1 including T2-weighted, fluid-attenuatd inversion recovery, and postcontrast Tl-weighted sequences. 2 We investigated the perfusion state of MS plaques using brain perfusion imaging in a 12-year-old boy with MS.

Current and future applications of magnetic resonance imaging and spectroscopy of the brain in hepatic encepha-lopathy

Hepatic encephalopathy （HE） is a common neuropsychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestations of HE are widely variable and involve a spectrum from mild subclinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging （MRI） techniques provide a non-invasive means of assessment of changes in brain volume （coregistered MRI） and impaired brain function （fMRI）, while proton magnetic resonance spectroscopy （^1H MRS） detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens.

The neuroimaging of neurodegenerative and vascular disease in the secondary prevention of cognitive decline

Structural brain changes indicative of dementia occur up to 20 years before the onset of clinical symptoms. Efforts to modify the disease process after the onset of cognitive symptoms have been unsuccessful in recent years. Thus, future trials must begin during the preclinical phases of the disease before symptom onset. Age related cognitive decline is often the result of two coexisting brain pathologies: Alzheimer's disease(amyloid, tau, and neurodegeneration) and vascular disease. This review article highlights some of the common neuroimaging techniques used to visualize the accumulation of neurodegenerative and vascular pathologies during the preclinical stages of dementia such as structural magnetic resonance imaging, positron emission tomography, and white matter hyperintensities. We also describe some emerging neuroimaging techniques such as arterial spin labeling, diffusion tensor imaging, and quantitative susceptibility mapping. Recent literature suggests that structural imaging may be the most sensitive and cost-effective marker to detect cognitive decline, while molecular positron emission tomography is primarily useful for detecting disease specific pathology later in the disease process. Currently, the presence of vascular disease on magnetic resonance imaging provides a potential target for optimizing vascular risk reduction strategies, and the presence of vascular disease may be useful when combined with molecular and metabolic markers of neurodegeneration for identifying the risk of cognitive impairment.

Computer-aided differential diagnosis system for Alzheimer’s disease based on machine learning with functional and morphological image features in magnetic resonance imaging

Alzheimer’s disease (AD) is a dementing disorder and one of the major public health problems in countries with greater longevity. The cerebral cortical thickness and cerebral blood flow (CBF), which are considered as morphological and functional image features, respectively, could be decreased in specific cerebral regions of patients with dementia of Alzheimer type. Therefore, the aim of this study was to develop a computer-aided classification system for AD patients based on machine learning with the morphological and functional image features derived from a magnetic resonance (MR) imaging system. The cortical thicknesses in ten cerebral regions were derived as morphological features by using gradient vector trajectories in fuzzy membership images. Functional CBF maps were measured with an arterial spin labeling technique, and ten regional CBF values were obtained by registration between the CBF map and Talairach atlas using an affine transformation and a free form deformation. We applied two systems based on an arterial neural network (ANN) and a support vector machine (SVM), which were trained with 4 morphological and 6 functional image features, to 15 AD patients and 15 clinically normal (CN) subjects for classification of AD. The area under the receiver operating characteristic curve (AUC) values for the two systems based on the ANN and SVM with both image?features were 0.901 and 0.915, respectively. The AUC values for the ANN-and SVM-based systems with the morphological features were 0.710 and 0.660, respectively, and those with the functional features were 0.878 and 0.903, respectively. Our preliminary results suggest that the proposed method may have potential for assisting radiologists in the differential diagnosis of AD patients by using morphological and functional image features.

Morphological and functional evaluation of chronic kidney disease using magnetic resonance imaging

X-ray computed tomography(CT),ultrasonography(US)and radionuclide scanning are important clinical methods for evaluating morphology of the kidney.These modalities are also applicable for estimating kidney function with time lapse analysis using proper contrastmedia as may be necessary.In the case of US,it can estimate kidney function based on the measurement of blood flow using the Doppler effect.Formerly,magnetic resonance imaging(MRI)was an inappropriate diagnostic imaging technique for abdominal organs because of their respiratory displacements.However,MRI is now actively used for kidney as well as liver or other parenchymal organs,in tandem with the technological advances.Unlike unenhanced X-ray CT,"conventional"MRI can distinguish the border between cortex and medulla in T1 or T2 weighted images.It was known that the border blurred with decreasing kidney function.Moreover,several other particular imaging methods were introduced in recent years,and these could be called"functional"MRI.In this review,the following are discussed:functional MRI for chronic kidney disease,which include blood oxygenation level-dependent MRI for evaluation of hypoxia,diffusion-weighted imagingfor evaluation of fibrosis,diffusion tensor imaging for evaluation of microstructure,and arterial spin labeling to evaluate the amount of organ perfusion,accompanied with several related articles.The ultimate goal of functional MRI is to provide useful in vivo information repeatedly for daily medical treatment non-invasively.

动脉自旋标记成像观察帕金森病患者纹状体-丘脑-皮层环路的代谢网络连接属性

目的 从代谢网络连接的角度探讨帕金森病(Parkinson’s disease, PD)患者纹状体-丘脑-皮层(striatal-thalamo-cortical,STC)环路紊乱的影像学特征。材料与方法 采用动脉自旋标记成像技术,获取62名PD患者以及65名健康对照(healthy control,HC)受试者的脑血流量(cerebral blood flow, CBF)数据。基于CBF信息计算两组STC环路代谢网络的连接属性,包括种子点-连接、皮层-连接及模块-连接。随后使用置换检验分别进行三种网络连接的组间比较。结果 两组的年龄、性别、受教育程度及认知量表评分差异均无统计学意义(P>0.05)。相较于HC受试者,PD患者其种子点-连接值在双侧颞下回、双侧梭状回、双侧额中回、左侧枕中回以及右侧中央后回等脑区显著增高,而在双侧颞中回、左侧额直回、左侧颞上回、双侧额下回、双侧楔前叶、右侧辅助运动区以及双侧顶下回等脑区显著减低(P<0.05);其与感觉运动皮层存在显著增强的皮层-连接、而与运动皮层及顶-枕叶皮层存在显著减弱的皮层-连接(P<0.05);模块-连接于额叶模块与运动模块、感觉运动模块与顶-枕叶模块以及顶-枕叶模块与颞叶模块之间呈现显著升高;而于额叶模块与颞叶模块、运动模块与顶-枕叶模块以及感觉运动模块与颞叶模块之间呈现显著降低(P<0.05)。结论 PD患者存在代谢层面的神经网络紊乱,涉及到STC环路内以基底节区为枢纽的广泛性连接异常。

基于动脉自旋标记成像技术探讨坏死性小肠结肠炎对早产儿脑血流量的影响

目的:基于动脉自旋标记成像技术(ASL)探讨坏死性小肠结肠炎(NEC)对早产儿脑血流量的影响。方法:选取2022年1月至2023年6月在郑州大学第三附属医院新生儿重症监护室住院治疗的37例NEC早产儿,按胎龄(±3 d)、出生体重(±300 g)1∶1匹配同期未患NEC的早产儿作为对照;所有早产儿均于纠正胎龄35~40周完善头颅常规MRI及ASL检查,获取脑血流值。应用线性回归分析NEC对不同脑功能区脑血流值的影响。2组患儿均于矫正胎龄40~44周时进行NBNA评分。结果:控制混杂因素后,NEC可升高早产儿右侧额叶、双侧颞叶、右侧枕叶、双侧基底神经节及双侧丘脑的脑血流值[β′(95%CI)分别为0.281(0.267~6.117)、0.234(0.055~4.088)(左侧)、0.318(0.601~5.736)(右侧)、0.272(0.234~8.523)、0.386(1.702~8.032)(左侧)、0.377(1.690~8.755)(右侧)、0.389(2.297~10.890)(左侧)、0.318(0.919~8.884)(右侧),P<0.05]。纠正胎龄40~44周,NEC组和对照组NBNA评分分别为36(34,37)、37(35,38)分,差异无统计学意义(P=0.187)。结论:早产儿发生NEC后脑血流值增高。

DWI联合3D动脉自旋标记技术对鞍旁脑膜瘤与海绵状血管瘤的鉴别诊断价值

目的:探讨DWI联合3D-ASL技术在鞍旁脑膜瘤与海绵状血管瘤的鉴别诊断价值。方法:回顾性分析经手术病理证实的鞍旁脑膜瘤与海绵状血管瘤各20例的MRI资料,分析平扫、增强扫描、DWI、3D-ASL图像特点,并测量最小ADC值及最大相对脑血流量(rCBF)。结果:鞍旁脑膜瘤多呈类圆形,T_(2)WI多呈等信号,增强扫描以早期中等程度强化常见,常见瘤周水肿及脑膜尾征;DWI多呈等高信号,最小ADC值(0.67~1.12)×10^(-3)mm^(2)/s,平均(0.76±0.13)×10^(-3)mm^(2)/s;多呈中高灌注,rCBF为5.072~9.683,平均7.062±3.571。海绵状血管瘤多呈哑铃状,T_(2)WI多呈高信号,增强扫描以充填式显著强化为主,未见瘤周水肿及脑膜尾征;DWI多呈低信号,最小ADC值(1.48~1.83)×10^(-3)mm^(2)/s,平均(1.56±0.25)×10^(-3)mm^(2)/s;多呈低灌注,rCBF为1.356~3.014,平均1.696±1.028。2组肿瘤形态、T_(2)WI信号、DWI信号、最小ADC值、强化方式、灌注信号及rCBF的差异均有统计学意义(均P<0.05)。结论:DWI联合3D-ASL技术在鞍旁脑膜瘤与海绵状血管瘤的鉴别诊断中具有较高的应用价值。

难治性癫痫患者海马灌注的3D-ASL成像评估

目的探讨难治性癫痫患者采用磁共振动脉自旋标记(ASL)技术评估海马灌注情况的价值。方法筛选2019-11-2021-11郴州市第一人民医院的105例受试者,均行海马3D-ASL检查,分为3组(单侧颞叶异常放电组、单侧海马硬化组、健康对照组),分析海马脑血流量(CBF)值与难治性颞叶癫痫的关系。结果健康对照组、单侧颞叶异常放电组患侧与健侧海马、单侧海马硬化组患侧与健侧海马的CBF值分别为(52.13±0.95)mL/(100 g·min)、(49.03±5.28)mL/(100 g·min)、(54.97±1.63)mL/(100 g·min)、(39.41±2.01)mL/(100 g·min)、(48.03±1.69)mL/(100 g·min),除健康对照组与单侧颞叶异常放电组健侧、单侧颞叶异常放电组健侧与单侧海马硬化组健侧比较无统计学差异外,其余组间比较差异均有统计学意义(P<0.00625)。对比健康对照组与单侧颞叶异常放电组患侧得出cut-off值,ROC曲线的最佳临界点为45.81。结论ASL技术在全身及系统性疾病中有一定的诊断价值,难治性颞叶癫痫患者的海马灌注量变化相较于影像学改变更早,有利于临床早期诊断和治疗。

MR动脉自旋标记成像技术在脑血管病及相关认知障碍疾病中的应用进展

动脉自旋标记(ASL)为无需对比剂的MR脑灌注成像技术,与金标准对比剂灌注成像具有良好的相关性。随着ASL在中枢神经系统重大疾病中的广泛应用,尤其是多延迟ASL、4D ASL和超选择单支血管标记技术在脑血管病及相关认知障碍疾病中的应用,大幅提升了ASL的应用效能。就ASL的技术进展及其在脑血管病和相关认知障碍疾病中的应用进行评述,以期在临床上进一步推广ASL新技术,为病人提供简便易行和经济的影像检查方法,为个体化诊断及治疗决策提供支持。

乳腺癌患者化疗后脑血流灌注异常的临床应用研究

目的应用磁共振成像中的动脉自旋标记(ASL)技术来探讨乳腺癌患者化疗后脑血流灌注变化及其与认知功能之间的相关性。方法前瞻性的收集43名自2020年1月至2022年12月经过手术病理证实的女性单侧乳腺癌患者(BC组),且所有患者在术后接受标准的化疗方案进行治疗。同时招募37名健康对照组(HC组),两组均采用西门子3.0T磁共振扫描仪进行常规头颅平扫及全脑ASL扫描,采用双样本t检验对各脑区脑血流量(CBF)值进行统计学分析。之后应用spearman相关性分析,探索存在血流灌注差异脑区的CBF值与神经量表之间的相关性。结果与HC组相比,BC组左侧小脑CrusII区、双侧颞中回CBF值降低,双侧豆状壳核CBF值增加(P<0.05,FWE校正)。相关性分析结果显示左侧小脑CrusII区、左侧颞中回、右侧颞中回CBF值与神经心理学量表MMSE呈正相关(r=0.429,P<0.01;r=0.413,P<0.01;r=0.405,P<0.01)。结论乳腺癌患者化疗后大脑存在多个脑区的脑血流灌注异常且存在与化疗相关的认知功能障碍。

三维动脉自旋标记成像序列与弥散加权成像在急性脑梗死鉴别诊断中的价值研究

目的研究在急性脑梗死鉴别诊断中三维动脉自旋标记成像(3D-ASL)序列与弥散加权成像(DWI)的应用价值。方法选定本院2020年11月至2023年12月收治的108例高度疑似急性脑梗死患者,所有入院患者均接受磁共振成像(MRI)扫描,分析患者的3D-ASL、DWI图像表现,以临床综合诊断为金标准,评估3D-ASL序列与DWI的诊断效能。结果108例疑似患者临床综合诊断,确诊阳性100例,而3D-ASL序列确诊急性脑梗死者97例,DWI确诊急性脑梗死者78例,诊断符合率、灵敏度、特异度3D-ASL高于DWI(P<0.05);3D-ASL、DWI成像参数值对比,病灶侧局部脑血流量(rCBF)、表观弥散系数(ADC值)低于健侧,差异有统计学意义(P<0.05);急性期、亚急性期、慢性期患者三维D-ASL、DWI成像参数值对比差异有统计学意义(P<0.05)。结论在急性脑梗死鉴别诊断中,3D-ASL诊断符合率与灵敏度要高于DWI,可为临床提供一定的参考依据,有重要的参考价值。

常规磁共振序列联合ASL在儿童局灶性皮层发育不良中的诊断价值

目的:分析局灶性皮质发育不良(FCD)患儿常规MRI序列及动脉自旋标记(ASL)的扫描图像,探讨其对FCD的诊断价值。方法:回顾性分析2021年7月至2023年8月经病理确诊为FCD的30例患儿MRI图像,包括常规MRI T1WI、T2WI、FLAIR序列及ASL扫描序列,分析FCD不同分型的MRI影像学特点,并对ASL图像经后处理获得病变区脑血流量(CBF)值及同水平对侧正常区CBF值进行比较,计算常规MRI序列及常规MRI序列联合ASL扫描序列诊断FCD的准确率。结果:常规MRI序列评估结果阳性21例,准确率为70%。FCD I型6例,主要表现为局部脑组织容积偏小,灰白质模糊;FCD II型7例,以皮层增厚,皮层及皮层下片状T1WI稍低信号,T2WI高信号,T2-FAIR高信号为主,典型者呈Tansmantle征;FCD III型8例,合并海马硬化、肿瘤、血管畸形。常规MRI序列及ASL联合扫描示27例灌注异常,准确率为90%,27例病灶区CBF值[(48.15±6.00)mL/(100g·min)]低于对侧正常区CBF值[(79.66±6.53)mL/(100g·min)](t=18.458,P<0.001)。结论:不同分型FCD具有特征性影像表现,但I型病灶较隐匿,II型典型表现出现概率少,容易漏诊,III型容易被合并病灶掩盖,ASL扫描序列有助于FCD病灶的检出及定位,与常规MRI序列联合检查可进一步提高诊断FCD的准确率。

Quantitative assessment of acute kidney injury by noninvasive arterial spin labeling perfusion MRI:a pilot study

The kidneys are essential for maintaining homeostasis,are responsible for the reabsorption of water,glucose and amino acids,and filter the blood by removing waste.Acute kidney injury(AKI) is a syndrome characterized by the rapid loss of renal excretory function and the accumulation of end metabolic products of urea and creatinine.AKI is associated with the later development of chronic kidney disease and end-stage kidney disease,and may eventually be fatal.Early diagnosis of AKI and assessments of the effects of treatment,however,are challenging.The pathophysiological mechanism of AKI is thought to be the imbalance between oxygen supply and demand in the kidneys.We have assessed the ability of arterial spin labeling(ASL) perfusion magnetic resonance imaging(MRI),without the administration of contrast media,to quantify renal blood flow(RBF) non-invasively.We found that RBF was significantly lower in AKI patients than in healthy volunteers.These results suggest that ASL perfusion MRI,a noninvasive measurement of RBF,may be useful in the early diagnosis of AKI.

多模态MRI功能成像在脑胶质瘤术后复发与治疗后反应评估中的价值

目的比较MR扩散加权成像(DWI)、三维动脉自旋标记成像(3D ASL)在鉴别脑胶质瘤术后复发与治疗后反应的诊断价值,为临床精准治疗提供客观依据。方法回顾分析我院2019年1月-2023年7月间行脑胶质瘤手术,术后放化疗1月以上,随访过程中首次出现异常强化病灶者47例,进行MRI平扫、DWI、3D ASL、增强扫描检查,分别测量DWI的表观扩散系数(ADC)值和相对ADC(rADC)值、3D ASL的血流动力学参数CBF值和相对CBF(rCBF)值。利用两样本t检验、受试者工作特征曲线(ROC)分析来评估研究参数在鉴别治疗后反应方面的诊断与胶质瘤术后复发效能。结果47例患者中,30例为脑胶质瘤复发,17例为治疗后反应,1.脑胶质瘤复发强化区CBF值为(119.16±18.58)mL/100g/1min,治疗后反应区的CBF值为(72.06±22.77)mL/100g/1min,差异有统计学意义(P<0.05);脑胶质瘤复发强化区rCBF值为3.56±1.13,放射损伤区的rCBF值为1.18±0.39,差异有统计学意义(P<0.05);2.ADC在脑胶质瘤复发和治疗后反应之间没有明显差异(P=0.235);rADC(P<0.05)在脑胶质瘤复发和治疗后反应之间差异有统计学意义;3.3D ASL(rCBF)诊断脑胶质瘤复发曲线下面积约0.971,ADC诊断脑胶质瘤复发曲线下面积约为0.675。结论与DWI序列相比,3D ASL成像技术在鉴别胶质瘤复发和治疗后反应方面显示出更好的诊断效能。