The concept of region of sensitivity is central to the field of diffuse optics and is closely related to the Jacobian matrix used to solve the inverse problem in imaging.It is well known that,in diffuse reflectance,th...The concept of region of sensitivity is central to the field of diffuse optics and is closely related to the Jacobian matrix used to solve the inverse problem in imaging.It is well known that,in diffuse reflectance,the region of sensitivity associated with a given source-detector pair is shaped as a banana,and features maximal sensitivity to the portions of the sample that are closest to the source and the detector.We have recently introduced a dual-slope(DS)method based on a special arrangement of two sources and two detectors,which results in deeper and more localized regions of sensitivity,resembling the shapes of different kinds of nuts.Here,we report the regions of sensitivity associated with a variety of source-detector arrangements for DS measurements of intensity and phase with frequency-domain spectroscopy(modulation frequency:140 MHz)in a medium with absorption and reduced scattering coefficients of 0.1 and 12 cm^(-1),respectively.The main result is that the depth of maximum sensitivity,considering only cases that use source-detector separations of 25 and 35 mm,progressively increases as we consider single-distance intensity(2.0mm),DS intensity(4.6mm),single-distance phase(7.5mm),and DS phase(10.9 mm).These results indicate the importance of DS measurements,and even more so of phase measurements,when it is desirable to selectively probe deeper portions of a sample with diffuse optics.This is certainly the case in non-invasive optical studies of brain,muscle,and breast tissue,which are located underneath the superficial tissue at variable depths.展开更多
近红外漫射光相关断层成像技术(Diffuse Correlation Tomography,DCT)是一种乳腺微血管血流成像的新技术,但成像的空间分辨率不足,高密度光源探测器(Source and Detector,S-D)阵列的布置方式是否可以有效提高DCT空间分辨率目前尚不清楚...近红外漫射光相关断层成像技术(Diffuse Correlation Tomography,DCT)是一种乳腺微血管血流成像的新技术,但成像的空间分辨率不足,高密度光源探测器(Source and Detector,S-D)阵列的布置方式是否可以有效提高DCT空间分辨率目前尚不清楚。为了研究S-D阵列密度对于DCT血流重建图像空间分辨率的影响,设计了3种S-D阵列,密度分别为24、48和96。结合蒙特卡洛仿真和DCT血流图像重建方法,研究了S-D阵列对于2种含有高血流异质物(模拟乳腺恶性肿瘤)的乳腺组织血流重建效果的影响。结果表明,高密度的SD阵列交错排布可以提高DCT血流重建的空间分辨率,可提升临床早期筛查时乳腺恶性肿瘤成像的精确性和稳定性。展开更多
Transcranial magnetic stimulation(TMS)has been established as an important and effective treatment for various psychiatric disorders.However,its effectiveness has likely been limited due to the dearth of neuronavigati...Transcranial magnetic stimulation(TMS)has been established as an important and effective treatment for various psychiatric disorders.However,its effectiveness has likely been limited due to the dearth of neuronavigational tools for targeting purposes,unclear ideal stimulation parameters,and a lack of knowledge regarding the physiological response of the brain to TMS in each psychiatric condition.Modern optical imaging modalities,such as functional near-infrared spectroscopy and diffuse optical tomography,are promising tools for the study of TMS optimization and functional targeting in psychiatric disorders.They possess a unique combination of high spatial and temporal resolutions,portability,real-time capability,and relatively low costs.In this mini-review,we discuss the advent of optical imaging techniques and their innovative use in several psychiatric conditions including depression,panic disorder,phobias,and eating disorders.With further investment and research in the development of these optical imaging approaches,their potential will be paramount for the advancement of TMS treatment protocols in psychiatry.展开更多
基金This research was supported by NIH Grant No.R01-NS095334.
文摘The concept of region of sensitivity is central to the field of diffuse optics and is closely related to the Jacobian matrix used to solve the inverse problem in imaging.It is well known that,in diffuse reflectance,the region of sensitivity associated with a given source-detector pair is shaped as a banana,and features maximal sensitivity to the portions of the sample that are closest to the source and the detector.We have recently introduced a dual-slope(DS)method based on a special arrangement of two sources and two detectors,which results in deeper and more localized regions of sensitivity,resembling the shapes of different kinds of nuts.Here,we report the regions of sensitivity associated with a variety of source-detector arrangements for DS measurements of intensity and phase with frequency-domain spectroscopy(modulation frequency:140 MHz)in a medium with absorption and reduced scattering coefficients of 0.1 and 12 cm^(-1),respectively.The main result is that the depth of maximum sensitivity,considering only cases that use source-detector separations of 25 and 35 mm,progressively increases as we consider single-distance intensity(2.0mm),DS intensity(4.6mm),single-distance phase(7.5mm),and DS phase(10.9 mm).These results indicate the importance of DS measurements,and even more so of phase measurements,when it is desirable to selectively probe deeper portions of a sample with diffuse optics.This is certainly the case in non-invasive optical studies of brain,muscle,and breast tissue,which are located underneath the superficial tissue at variable depths.
文摘近红外漫射光相关断层成像技术(Diffuse Correlation Tomography,DCT)是一种乳腺微血管血流成像的新技术,但成像的空间分辨率不足,高密度光源探测器(Source and Detector,S-D)阵列的布置方式是否可以有效提高DCT空间分辨率目前尚不清楚。为了研究S-D阵列密度对于DCT血流重建图像空间分辨率的影响,设计了3种S-D阵列,密度分别为24、48和96。结合蒙特卡洛仿真和DCT血流图像重建方法,研究了S-D阵列对于2种含有高血流异质物(模拟乳腺恶性肿瘤)的乳腺组织血流重建效果的影响。结果表明,高密度的SD阵列交错排布可以提高DCT血流重建的空间分辨率,可提升临床早期筛查时乳腺恶性肿瘤成像的精确性和稳定性。
文摘Transcranial magnetic stimulation(TMS)has been established as an important and effective treatment for various psychiatric disorders.However,its effectiveness has likely been limited due to the dearth of neuronavigational tools for targeting purposes,unclear ideal stimulation parameters,and a lack of knowledge regarding the physiological response of the brain to TMS in each psychiatric condition.Modern optical imaging modalities,such as functional near-infrared spectroscopy and diffuse optical tomography,are promising tools for the study of TMS optimization and functional targeting in psychiatric disorders.They possess a unique combination of high spatial and temporal resolutions,portability,real-time capability,and relatively low costs.In this mini-review,we discuss the advent of optical imaging techniques and their innovative use in several psychiatric conditions including depression,panic disorder,phobias,and eating disorders.With further investment and research in the development of these optical imaging approaches,their potential will be paramount for the advancement of TMS treatment protocols in psychiatry.
