Amide proton transfer (APT) magnetic resonance imaging (MRI) is an important molecularimaging technique at the protein level in tissue. Neurodegenerative diseases have a highlikelihood of causing abnormal protein accu...Amide proton transfer (APT) magnetic resonance imaging (MRI) is an important molecularimaging technique at the protein level in tissue. Neurodegenerative diseases have a highlikelihood of causing abnormal protein accumulation in the brain, which can be detectedby APT MRI. This article briefly introduces the principles and image processing technologyof APT MRI, and reviews the current state of research on Alzheimer's disease and Parkinson's disease using this technique. Early applications of this approach in these twoneurodegenerative diseases are encouraging, which also suggests continued technicaldevelopment and larger clinical trials to gauge the value of this technique.展开更多
目的对比磁共振酰胺质子转移(Amide Proton Transfer,APT)成像、扩散加权成像(Diffusion Weighted Imaging,DWI)和动态增强(Dynamic Contrast-Enhanced,DCE)成像以及3者联合应用在鉴别乳腺良恶性病变中的诊断价值。方法纳入55例乳腺疾...目的对比磁共振酰胺质子转移(Amide Proton Transfer,APT)成像、扩散加权成像(Diffusion Weighted Imaging,DWI)和动态增强(Dynamic Contrast-Enhanced,DCE)成像以及3者联合应用在鉴别乳腺良恶性病变中的诊断价值。方法纳入55例乳腺疾病患者,均进行APT、DWI以及DCE扫描,测量非对称磁化转移(Magnetization Transfer Asymmetry,MTRasym)率和表观扩散系数(Apparent Diffusion Coefficient,ADC)值,并记录乳腺影像报告和数据系统的分类。分析乳腺良恶性病变各参数之间的差异,使用Logistic回归建立联合诊断模型,采用受试者工作特征曲线(Receive Operating Characteristic,ROC)计算各诊断模型在乳腺良恶性病变中的诊断价值,并比较恶性病变中不同病理因素组间的差异以及各病理因素与APT之间的相关性。结果恶性组中MTRasym和ADC值均小于良性组,差异具有统计学意义(均P<0.05),DWI、APT、DCE以及APT+DCE、APT+DWI、DCE+DWI、DWI+APT+DCE联合模型鉴别乳腺良恶性病变的曲线下面积(Area Under Curve,AUC)分别为0.804、0.723、0.741以及0.782、0.895、0.897、0.970;DWI+APT+DCE联合诊断模型的AUC显著大于DWI、APT、DCE以及任意两者联合诊断模型(均P<0.05)。Ki-67高表达组的MTRasym值较低表达组高[(3.934%±0.883%)v s.(3.192%±0.949%)],乳腺癌浸润程度组织学分级Ⅲ级组的M T R a s y m值较Ⅱ级组高[(4.225%±0.932%)vs.(3.451%±0.873%)],差异均有统计学意义(均P<0.05),并且APT与两者均呈中度正相关(r=0.627、0.537,均P<0.05)。结论APT成像技术在乳腺良恶性病变的鉴别中具有较好的诊断价值,与常规DWI、DCE成像无显著差异,并且三者联合应用的诊断价值更高。展开更多
The purpose of this study was to demonstrate a simple and fast method for solving the time-dependent Bloch-McConnell equations describing the behavior of magnetization in magnetic resonance imaging (MRI) in the presen...The purpose of this study was to demonstrate a simple and fast method for solving the time-dependent Bloch-McConnell equations describing the behavior of magnetization in magnetic resonance imaging (MRI) in the presence of multiple chemical exchange pools. First, the time-dependent Bloch- McConnell equations were reduced to a homogeneous linear differential equation, and then a simple equation was derived to solve it using a matrix operation and Kronecker tensor product. From these solutions, the longitudinal relaxation rate (R1ρ) and transverse relaxation rate in the rotating frame (R2ρ) and Z-spectra were obtained. As illustrative examples, the numerical solutions for linear and star-type three-pool chemical exchange models and linear, star- type, and kite-type four-pool chemical exchange models were presented. The effects of saturation time (ST) and radiofrequency irradiation power (ω1) on the chemical exchange saturation transfer (CEST) effect in these models were also investigated. Although R1ρ and R2ρ were not affected by the ST, the CEST effect observed in the Z-spectra increased and saturated with increasing ST. When ω1 was varied, the CEST effect increased with increasing ω1 in R1ρ, R2ρ, and Z-spectra. When ω1 was large, however, the spillover effect due to the direct saturation of bulk water protons also increased, suggesting that these parameters must be determined in consideration of both the CEST and spillover effects. Our method will be useful for analyzing the complex CEST contrast mechanism and for investigating the optimal conditions for CEST MRI in the presence of multiple chemical exchange pools.展开更多
目的探讨酰胺质子转移加权(APTw)成像联合mDixon-Quant序列鉴别Ⅰ期子宫内膜癌(EC)与子宫内膜息肉(EP)的价值。方法回顾性分析2019年5月至2021年5月经手术病理证实的37例Ⅰ期EC和27例EP的患者资料,所有患者术前均行3.0 T MR检查,扫描序...目的探讨酰胺质子转移加权(APTw)成像联合mDixon-Quant序列鉴别Ⅰ期子宫内膜癌(EC)与子宫内膜息肉(EP)的价值。方法回顾性分析2019年5月至2021年5月经手术病理证实的37例Ⅰ期EC和27例EP的患者资料,所有患者术前均行3.0 T MR检查,扫描序列包括T_(1)WI、T_(2)WI、APTw和mDixon-Quant。由两位观察者分别测量病灶APTw成像的APT值,mDixon-Quant成像的R_(2)^(*)值及脂肪分数(FF)值。采用组内相关系数(ICC)对两位观察者各参数测量结果的一致性进行检验;根据数据符合正态分布与否,采用独立样本t检验或Mann-Whitney秩和检验比较各参数值的差异,采用受试者工作特征(ROC)曲线评估有统计学差异的参数对早期EC与EP的鉴别诊断的曲线下面积(AUC)。采用Logistic回归计算APTw联合mDIXON-Quant鉴别早期EC与EP的AUC。采用Delong检验比较AUC间的差异性。结果两位观察者测得两组病灶各参数值的一致性良好(ICC>0.75)。早期EC的APT值(3.03±1.03)%及R_(2)^(*)值(21.73±8.19)Hz大于EP的APT值(2.02±0.53)%与R_(2)^(*)值(16.72±3.82)Hz,差异均具有统计学意义。APT值、R_(2)^(*)值以及二者联合鉴别早期EC与EP的AUC、阈值、敏感度、特异度分别为0.829、0.691、0.848;2.775%、21.783 Hz;56.40%、41.00%、71.80%;100.00%、96.40%、96.40%。APT值鉴别早期EC与EP的AUC与R_(2)^(*)值的AUC、APT值的AUC与二者联合的AUC以及R_(2)^(*)值与二者联合的AUC之间的差异的P值分别为0.07、0.45、0.01。结论 APT值、R_(2)^(*)值可定量鉴别早期EC与EP,二者联合诊断效能得到了提升,具有一定的临床应用价值。展开更多
文摘Amide proton transfer (APT) magnetic resonance imaging (MRI) is an important molecularimaging technique at the protein level in tissue. Neurodegenerative diseases have a highlikelihood of causing abnormal protein accumulation in the brain, which can be detectedby APT MRI. This article briefly introduces the principles and image processing technologyof APT MRI, and reviews the current state of research on Alzheimer's disease and Parkinson's disease using this technique. Early applications of this approach in these twoneurodegenerative diseases are encouraging, which also suggests continued technicaldevelopment and larger clinical trials to gauge the value of this technique.
文摘目的对比磁共振酰胺质子转移(Amide Proton Transfer,APT)成像、扩散加权成像(Diffusion Weighted Imaging,DWI)和动态增强(Dynamic Contrast-Enhanced,DCE)成像以及3者联合应用在鉴别乳腺良恶性病变中的诊断价值。方法纳入55例乳腺疾病患者,均进行APT、DWI以及DCE扫描,测量非对称磁化转移(Magnetization Transfer Asymmetry,MTRasym)率和表观扩散系数(Apparent Diffusion Coefficient,ADC)值,并记录乳腺影像报告和数据系统的分类。分析乳腺良恶性病变各参数之间的差异,使用Logistic回归建立联合诊断模型,采用受试者工作特征曲线(Receive Operating Characteristic,ROC)计算各诊断模型在乳腺良恶性病变中的诊断价值,并比较恶性病变中不同病理因素组间的差异以及各病理因素与APT之间的相关性。结果恶性组中MTRasym和ADC值均小于良性组,差异具有统计学意义(均P<0.05),DWI、APT、DCE以及APT+DCE、APT+DWI、DCE+DWI、DWI+APT+DCE联合模型鉴别乳腺良恶性病变的曲线下面积(Area Under Curve,AUC)分别为0.804、0.723、0.741以及0.782、0.895、0.897、0.970;DWI+APT+DCE联合诊断模型的AUC显著大于DWI、APT、DCE以及任意两者联合诊断模型(均P<0.05)。Ki-67高表达组的MTRasym值较低表达组高[(3.934%±0.883%)v s.(3.192%±0.949%)],乳腺癌浸润程度组织学分级Ⅲ级组的M T R a s y m值较Ⅱ级组高[(4.225%±0.932%)vs.(3.451%±0.873%)],差异均有统计学意义(均P<0.05),并且APT与两者均呈中度正相关(r=0.627、0.537,均P<0.05)。结论APT成像技术在乳腺良恶性病变的鉴别中具有较好的诊断价值,与常规DWI、DCE成像无显著差异,并且三者联合应用的诊断价值更高。
文摘The purpose of this study was to demonstrate a simple and fast method for solving the time-dependent Bloch-McConnell equations describing the behavior of magnetization in magnetic resonance imaging (MRI) in the presence of multiple chemical exchange pools. First, the time-dependent Bloch- McConnell equations were reduced to a homogeneous linear differential equation, and then a simple equation was derived to solve it using a matrix operation and Kronecker tensor product. From these solutions, the longitudinal relaxation rate (R1ρ) and transverse relaxation rate in the rotating frame (R2ρ) and Z-spectra were obtained. As illustrative examples, the numerical solutions for linear and star-type three-pool chemical exchange models and linear, star- type, and kite-type four-pool chemical exchange models were presented. The effects of saturation time (ST) and radiofrequency irradiation power (ω1) on the chemical exchange saturation transfer (CEST) effect in these models were also investigated. Although R1ρ and R2ρ were not affected by the ST, the CEST effect observed in the Z-spectra increased and saturated with increasing ST. When ω1 was varied, the CEST effect increased with increasing ω1 in R1ρ, R2ρ, and Z-spectra. When ω1 was large, however, the spillover effect due to the direct saturation of bulk water protons also increased, suggesting that these parameters must be determined in consideration of both the CEST and spillover effects. Our method will be useful for analyzing the complex CEST contrast mechanism and for investigating the optimal conditions for CEST MRI in the presence of multiple chemical exchange pools.
文摘目的探讨酰胺质子转移加权(APTw)成像联合mDixon-Quant序列鉴别Ⅰ期子宫内膜癌(EC)与子宫内膜息肉(EP)的价值。方法回顾性分析2019年5月至2021年5月经手术病理证实的37例Ⅰ期EC和27例EP的患者资料,所有患者术前均行3.0 T MR检查,扫描序列包括T_(1)WI、T_(2)WI、APTw和mDixon-Quant。由两位观察者分别测量病灶APTw成像的APT值,mDixon-Quant成像的R_(2)^(*)值及脂肪分数(FF)值。采用组内相关系数(ICC)对两位观察者各参数测量结果的一致性进行检验;根据数据符合正态分布与否,采用独立样本t检验或Mann-Whitney秩和检验比较各参数值的差异,采用受试者工作特征(ROC)曲线评估有统计学差异的参数对早期EC与EP的鉴别诊断的曲线下面积(AUC)。采用Logistic回归计算APTw联合mDIXON-Quant鉴别早期EC与EP的AUC。采用Delong检验比较AUC间的差异性。结果两位观察者测得两组病灶各参数值的一致性良好(ICC>0.75)。早期EC的APT值(3.03±1.03)%及R_(2)^(*)值(21.73±8.19)Hz大于EP的APT值(2.02±0.53)%与R_(2)^(*)值(16.72±3.82)Hz,差异均具有统计学意义。APT值、R_(2)^(*)值以及二者联合鉴别早期EC与EP的AUC、阈值、敏感度、特异度分别为0.829、0.691、0.848;2.775%、21.783 Hz;56.40%、41.00%、71.80%;100.00%、96.40%、96.40%。APT值鉴别早期EC与EP的AUC与R_(2)^(*)值的AUC、APT值的AUC与二者联合的AUC以及R_(2)^(*)值与二者联合的AUC之间的差异的P值分别为0.07、0.45、0.01。结论 APT值、R_(2)^(*)值可定量鉴别早期EC与EP,二者联合诊断效能得到了提升,具有一定的临床应用价值。
