Abstract:
:The Newton-Raphson (N-R) with two different regularization methods: the Levenberg-Marquardt (N-R-LM) and the Hachtel's Augmented Matrix (N-R-HAM), were used to reconstruct images of conductivity changes in a cylindrical medium by Induced Current Electrical Impedance Tomography (ic-EIT). Experimental data were obtained from an 8-cm high, 19.2-cm diameter tank with 16 electrodes on the boundary surface and surrounded by eight 50-cm diameter coils. The coils were angularly displaced by 45 degrees and offset 12.4 cm from the center of the tank. They were driven by a 150-mA (peak) 20-kHz sine wave. Potential differences between adjacent electrodes were measured with phase-sensitive demodulators. The scalar potential field in the electrode plane of the conducting medium, resulting from eddy currents generated by each coil, was computed by the Finite Element Method. Image reconstruction by the N-R-HAM method was found to provide higher resolution and better noise immunity than the N-R-LM method. Two 2.2-cm diameter nonconducting rods located 3.9 cm from the center of the tank, 180 degrees from each other, were clearly resolved. Spatial resolution is estimated at 15% of the tank diameter and is comparable to the resolution obtained by conventional EIT using the Sheffield protocol. Higher resolution could be achieved with more coils and/or electrodes. A 16-coil system should present no construction problems. However, voltages induced by stray magnetic flux through the electrode leads and measurement circuits are significant and may limit the ability of ic-EIT to perform static imaging of conductivity distributions.
journal_name
IEEE Trans Med Imagingjournal_title
IEEE transactions on medical imagingauthors
Ruan W,Guardo R,Adler Adoi
10.1109/42.491419subject
Has Abstractpub_date
1996-01-01 00:00:00pages
180-7issue
2eissn
0278-0062issn
1558-254Xjournal_volume
15pub_type
杂志文章abstract::In in-utero MRI, motion correction for fetal body and placenta poses a particular challenge due to the presence of local non-rigid transformations of organs caused by bending and stretching. The existing slice-to-volume registration (SVR) reconstruction methods are widely employed for motion correction of fetal brain ...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2020.2974844
更新日期:2020-09-01 00:00:00
abstract::The automatic diagnosis of various retinal diseases from fundus images is important to support clinical decision-making. However, developing such automatic solutions is challenging due to the requirement of a large amount of human-annotated data. Recently, unsupervised/self-supervised feature learning techniques recei...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2020.3008871
更新日期:2020-12-01 00:00:00
abstract::In this paper a psychophysical experiment and a multidimensional scaling (MDS) analysis are undergone to determine the physical characteristics that physicians employ to diagnose a burn depth. Subsequently, these characteristics are translated into mathematical features, correlated with these physical characteristics ...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2013.2254719
更新日期:2013-06-01 00:00:00
abstract::With the widespread use of positron emission tomography (PET) crystals with greatly improved energy resolution (e.g., 11.5% with LYSO as compared to 20% with BGO) and of list-mode acquisitions, the use of the energy of individual events in scatter correction schemes becomes feasible. We propose a novel scatter approac...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2010.2095025
更新日期:2011-03-01 00:00:00
abstract::A novel approach to correcting for intensity nonuniformity in magnetic resonance (MR) data is described that achieves high performance without requiring a model of the tissue classes present. The method has the advantage that it can be applied at an early stage in an automated data analysis, before a tissue model is a...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/42.668698
更新日期:1998-02-01 00:00:00
abstract::Optical Diffusion Tomography (ODT) is a modern non-invasive medical imaging modality which requires mathematical modelling of near-infrared light propagation in tissue. Solving the ODT forward problem equation accurately and efficiently is crucial. Typically, the forward problem is represented by a Diffusion PDE and i...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2016.2641500
更新日期:2017-04-01 00:00:00
abstract::Ultrasonography and photoacoustic tomography provide complementary contrasts in preclinical studies, disease diagnoses, and imaging-guided interventional procedures. Here, we present a video-rate (20 Hz) dual-modality ultrasound and photoacoustic tomographic platform that has a high resolution, rich contrasts, deep pe...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2020.3017815
更新日期:2020-12-01 00:00:00
abstract::Image textures in computed tomography colonography (CTC) have great potential for differentiating non-neoplastic from neoplastic polyps and thus can advance the current CTC detection-only paradigm to a new level with diagnostic capability. However, image textures are frequently compromised, particularly in low-dose CT...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2016.2518958
更新日期:2016-06-01 00:00:00
abstract::An automatic method has been developed for segmentation of abdominal computed tomography (CT) images for virtual colonoscopy obtained after a bowel preparation of a low-residue diet with ingested contrast solutions to enhance the image intensities of residual colonic materials. Removal of the enhanced materials was pe...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/42.897814
更新日期:2000-12-01 00:00:00
abstract::In Soares et al. (2000), the ensemble statistical properties of the rescaled block-iterative expectation-maximization (RBI-EM) reconstruction algorithm and rescaled block-iterative simultaneous multiplicative algebraic reconstruction technique (RBI-SMART) were derived. Included in this analysis were the special cases ...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/tmi.2004.836876
更新日期:2005-01-01 00:00:00
abstract::In magnetic resonance imaging (MRI), it is well-known that patient motion plays a significant role in the degradation of image quality. Although the case of translational in-plane motion (x-y-motion) has been studied by several researchers, the effect of rigid, translational out-of-plane motion (z-motion) has not yet ...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/42.414611
更新日期:1995-01-01 00:00:00
abstract:PURPOSE:Demonstration of a technique for three-dimensional (3-D) assessment of tracheal-stenoses, regarding site, length and degree, based on spiral computed tomography (S-CT). PATIENTS AND METHODS:S-CT scanning and automated segmentation of the laryngo-tracheal tract (LTT) was followed by the extraction of the LTT me...
journal_title:IEEE transactions on medical imaging
pub_type: 临床试验,杂志文章
doi:10.1109/42.996344
更新日期:2002-03-01 00:00:00
abstract::The success of prostate brachytherapy critically depends on delivering adequate dose to the prostate gland. Intraoperative localization of the implanted seeds provides potential for dose evaluation and optimization during therapy. A reduced-dimensionality matching algorithm for prostate brachytherapy seed reconstructi...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2010.2059709
更新日期:2011-01-01 00:00:00
abstract::Online acquisition of Cherenkov and portal imaging data was combined with a reconstruction scheme called EC3-D, providing a full 3-D dosimetry of megavoltage X-ray beams in a water tank. The methodology was demonstrated and quantified in a single static beam. Furthermore, the dynamics and visualization of the 3-D dose...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2017.2717800
更新日期:2017-10-01 00:00:00
abstract::We present a new approach to anisotropic diffusion based on a multidirectional diffusion flux. The diffusion flux is decomposed in an orthogonal basis, effectively enabling enhancement of contours as well as diffusion along the contours. To this end, we have selected a three-dimensional basis that depicts the directio...
journal_title:IEEE transactions on medical imaging
pub_type: 信件
doi:10.1109/TMI.2002.806403
更新日期:2002-11-01 00:00:00
abstract::Electromagnetic brain imaging is the reconstruction of brain activity from non-invasive recordings of the magnetic fields and electric potentials. An enduring challenge in this imaging modality is estimating the number, location, and time course of sources, especially for the reconstruction of distributed brain source...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2019.2932290
更新日期:2020-03-01 00:00:00
abstract::Optoacoustic (photoacoustic) dermoscopy offers two principal advantages over conventional optical imaging applied in dermatology. First, it yields high-resolution cross-sectional images of the skin at depths not accessible to other non-invasive optical imaging methods. Second, by resolving absorption spectra at multip...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2017.2664142
更新日期:2017-06-01 00:00:00
abstract::Most strain imaging techniques follow a pipeline strategy: in the first step, tissue displacement is estimated from radio-frequency (RF) frames, and in the second step, a spatial derivative operation is applied. There are two main issues that arise from this framework. First, the gradient operation amplifies noise, an...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2017.2685522
更新日期:2017-06-01 00:00:00
abstract::Spatial normalization is frequently used to map data to a standard coordinate system by removing intersubject morphological differences, thereby allowing for group analysis to be carried out. The work presented in this paper is motivated by the need for an automated cortical surface normalization technique that will a...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2008.925080
更新日期:2008-12-01 00:00:00
abstract::Computed ultrasound tomography in echo mode (CUTE) is a promising ultrasound (US) based multi-modal technique that allows to image the spatial distribution of speed of sound (SoS) inside tissue using hand-held pulse-echo US. It is based on measuring the phase shift of echoes when detected under varying steering angles...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2020.3029286
更新日期:2020-10-07 00:00:00
abstract::The response characteristics of two tomographic systems were compared for imaging of positron emitters: a) a SPECT system with a 3/8 in crystal and 511 keV detector shielding, equipped with a specially designed 511 keV collimator, and b) a PET V system using coincidence detection. SPECT transverse plane resolution was...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.1986.4307776
更新日期:1986-01-01 00:00:00
abstract::Many segmentation methods for thoracic volume data require manual input in the form of a seed point, initial contour, volume of interest etc. The aim of the work presented here is to further automate this segmentation initialization step. In this paper an anatomical modeling and matching method is proposed to coarsely...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/42.764893
更新日期:1999-03-01 00:00:00
abstract::Look-up tables (LUTs) are a common method for increasing the speed of many algorithms. Their use can be extended to the reconstruction of nonuniformly sampled k-space data using either a discrete Fourier transform (DFT) algorithm or a convolution-based gridding algorithm. A table for the DFT would be precalculated arr...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/42.918471
更新日期:2001-03-01 00:00:00
abstract::Atherosclerosis at the carotid bifurcation resulting in cerebral emboli is a major cause of ischemic stroke. Most strokes associated with carotid atherosclerosis can be prevented by lifestyle/dietary changes and pharmacological treatments if identified early by monitoring carotid plaque changes. Registration of 3-D ul...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2008.918326
更新日期:2008-10-01 00:00:00
abstract::We have developed a general-purpose registration algorithm for medical images and volumes. This method models the transformation between images as locally affine but globally smooth. The model also explicitly accounts for local and global variations in image intensities. This approach is built upon a differential mult...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2003.815069
更新日期:2003-07-01 00:00:00
abstract::In this paper, we propose a robust wavelet domain method for noise filtering in medical images. The proposed method adapts itself to various types of image noise as well as to the preference of the medical expert; a single parameter can be used to balance the preservation of (expert-dependent) relevant details against...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2003.809588
更新日期:2003-03-01 00:00:00
abstract::A convenient way to analyze blood-oxygen-level-dependent functional magnetic resonance imaging data consists of modeling the whole brain as a stationary, linear system characterized by its transfer function: the hemodynamic response function (HRF). HRF estimation, though of the greatest interest, is still under invest...
journal_title:IEEE transactions on medical imaging
pub_type: 临床试验,杂志文章
doi:10.1109/TMI.2004.831221
更新日期:2004-08-01 00:00:00
abstract::The comment of Stig Steenstrup on the use of gray level entropy function in our paper' has been addressed. The entropy measure has not been used in the procedure of enhancement, but it has only been used to show statistically that the enhanced images have larger gray level entropy, and therefore better utilize the gra...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.1987.4307802
更新日期:1987-01-01 00:00:00
abstract::Strategies for improvement of blood flow by promoting new vessel growth in ischemic tissue are being developed. Recently, contrast-enhanced ultrasound (CEU) imaging has been used to assess tissue perfusion in models of ischemia-related angiogenesis, growth-factor mediated angiogenesis, and tumor angiogenesis. In these...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/tmi.2006.877442
更新日期:2006-08-01 00:00:00
abstract::In this paper, we present a novel technique based on nonrigid image registration for myocardial motion estimation using both untagged and 3-D tagged MR images. The novel aspect of our technique is its simultaneous usage of complementary information from both untagged and 3-D tagged MR images. To estimate the motion wi...
journal_title:IEEE transactions on medical imaging
pub_type: 杂志文章
doi:10.1109/TMI.2012.2188104
更新日期:2012-06-01 00:00:00