Abstract：
:We present a general wavelet-based denoising scheme for functional magnetic resonance imaging (fMRI) data and compare it to Gaussian smoothing, the traditional denoising method used in fMRI analysis. One-dimensional WaveLab thresholding routines were adapted to two-dimensional (2-D) images, and applied to 2-D wavelet coefficients. To test the effect of these methods on the signal-to-noise ratio (SNR), we compared the SNR of 2-D fMRI images before and after denoising, using both Gaussian smoothing and wavelet-based methods. We simulated a fMRI series with a time signal in an active spot, and tested the methods on noisy copies of it. The denoising methods were evaluated in two ways: by the average temporal SNR inside the original activated spot, and by the shape of the spot detected by thresholding the temporal SNR maps. Denoising methods that introduce much smoothness are better suited for low SNRs, but for images of reasonable quality they are not preferable, because they introduce heavy deformations. Wavelet-based denoising methods that introduce less smoothing preserve the sharpness of the images and retain the original shapes of active regions. We also performed statistical parametric mapping on the denoised simulated time series, as well as on a real fMRI data set. False discovery rate control was used to correct for multiple comparisons. The results show that the methods that produce smooth images introduce more false positives. The less smoothing wavelet-based methods, although generating more false negatives, produce a smaller total number of errors than Gaussian smoothing or wavelet-based methods with a large smoothing effect.
journal_name
IEEE Trans Med Imagingjournal_title
IEEE transactions on medical imagingauthors
Wink AM,Roerdink JBdoi
10.1109/TMI.2004.824234subject
Has Abstractpub_date
2004-03-01 00:00:00pages
374-87issue
3eissn
0278-0062issn
1558-254Xjournal_volume
23pub_type
杂志文章abstract：:Magnetic Resonance-Electrical Properties Tomography (MR-EPT) is an imaging modality that maps the spatial distribution of the electrical conductivity and permittivity using standard MRI systems. The presence of a body within the scanner alters the RF field, and by mapping these alterations it is possible to recover th...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2015.2466082
更新日期：2016-01-01 00:00:00
abstract：:Psoriasis is a chronic inflammatory skin disease that affects over 3% of the population. Various methods are currently used to evaluate psoriasis severity and to monitor therapeutic response. The PASI system of scoring is widely used for evaluating psoriasis severity. It employs a visual analogue scale to score the th...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2012.2236349
更新日期：2013-04-01 00:00:00
abstract：:A true three-dimensional cone-beam reconstruction (TTCR) algorithm for direct volume image reconstruction from 2-D cone-beam projections is developed for the complete sphere geometry. The algorithm is derived from the parallel-beam true three-dimensional reconstruction (TTR) algorithm and is based on the modified filt...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.41483
更新日期：1989-01-01 00:00:00
abstract：:Functional magnetic resonance imaging (fMRI) provides a window on the human brain at work. Spontaneous brain activity measured during resting-state has already provided many insights into brain function. In particular, recent interest in dynamic interactions between brain regions has increased the need for more advanc...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2017.2755369
更新日期：2018-01-01 00:00:00
abstract：:Microwave radar imaging is promising as a complementary medical imaging modality. However, the unique nature of the images means interpretation can be difficult. As a result, it is important to understand the sources of image differences, and how much variability is inherent in the imaging system itself. To address th...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2018.2806878
更新日期：2018-08-01 00:00:00
abstract：:Detecting tools in surgical videos is an important ingredient for context-aware computer-assisted surgical systems. To this end, we present a new surgical tool detection dataset and a method for joint tool detection and pose estimation in 2d images. Our two-stage pipeline is data-driven and relaxes strong assumptions ...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2015.2450831
更新日期：2015-12-01 00:00:00
abstract：:Magnetic resonance (MR) tagging has been shown to be a useful technique for noninvasively measuring the deformation of an in vivo heart. An important step in analyzing tagged images is the identification of tag lines in each image of a cine sequence. Most existing tag identification algorithms require user defined myo...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.768842
更新日期：1999-04-01 00:00:00
abstract：:The aim of this study was to provide mathematical descriptors for the border of pigmented skin lesion images and to assess their efficacy for distinction among different lesion groups. New descriptors such as lesion slope and lesion slope regularity are introduced and mathematically defined. A new algorithm based on t...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2003.815901
更新日期：2003-08-01 00:00:00
abstract：:The feasibility of K-edge imaging using energy-resolved, photon-counting transmission measurements in X-ray computed tomography (CT) has been demonstrated by simulations and experiments. The method is based on probing the discontinuities of the attenuation coefficient of heavy elements above and below the K-edge energ...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2011.2142188
更新日期：2011-09-01 00:00:00
abstract：:We investigate using dual time-point PET data to perform Patlak modeling. This approach can be used for whole body dynamic PET studies in which we compute voxel-wise estimates of Patlak parameters using two frames of data for each bed position. Our approach directly uses list-mode arrival times for each event to estim...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2014.2298868
更新日期：2014-04-01 00:00:00
abstract：:We propose a joint information approach for automatic analysis of 2D echocardiography (echo) data. The approach combines a priori images, their segmentations and patient diagnostic information within a unified framework to determine various clinical parameters, such as cardiac chamber volumes, and cardiac disease labe...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2016.2593900
更新日期：2017-01-01 00:00:00
abstract：:Image guided interventions have seen growing interest in recent years. The use of X-rays for the procedure impels limiting the dose over time. Image sequences obtained thereby exhibit high levels of noise and very low contrasts. Hence, the development of efficient methods to enable optimal visualization of these seque...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2014.2349034
更新日期：2015-01-01 00:00:00
abstract：:A minimalist numerical model of white matter is presented, the objective of which is to help provide a biological basis for improved diffusion tensor imaging (DTI) analysis. Water diffuses, relaxes, and exchanges in three compartments-intracellular, extracellular, and myelin sheath. Exchange between compartments is de...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2007.906787
更新日期：2007-11-01 00:00:00
abstract：:This paper introduces and evaluates a block-iterative Fisher scoring (BFS) algorithm. The algorithm provides regularized estimation in tomographic models of projection data with Poisson variability. Regularization is achieved by penalized likelihood with a general quadratic penalty. Local convergence of the block-iter...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2008.918355
更新日期：2008-08-01 00:00:00
abstract：:A computationally efficient mixed feature based neural network (MFNN) is proposed for the detection of microcalcification clusters (MCCs) in digitized mammograms. The MFNN employs features computed in both the spatial and spectral domain and uses spectral entropy as a decision parameter. Backpropagation with Kalman fi...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.538936
更新日期：1996-01-01 00:00:00
abstract：:This paper presents a new variational method for the segmentation of a moving object against a still background, over a sequence of [two-dimensional or three-dimensional (3-D)] image frames. The method is illustrated in application to myocardial gated single photon emission computed tomography (SPECT) data, and incorp...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.932748
更新日期：2001-07-01 00:00:00
abstract：:Synthesizing a CT image from an available MR image has recently emerged as a key goal in radiotherapy treatment planning for cancer patients. CycleGANs have achieved promising results on unsupervised MR-to-CT image synthesis; however, because they have no direct constraints between input and synthetic images, cycleGAN...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2020.3015379
更新日期：2020-12-01 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：:The duration of a positron emission tomography (PET) imaging scan can be reduced if the transmission scan of one patient which is used for emission correction can be synthesized by using the reference transmission scan of another patient. In this paper, we propose a new intersubjects PET emission scan registration met...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.640744
更新日期：1997-10-01 00:00:00
abstract：:The analysis of MR images is evolving from qualitative to quantitative. More and more, the question asked by clinicians is how much and where, rather than a simple statement on the presence or absence of abnormalities. The authors present a study in which the results obtained with a semiautomatic, multispectral segmen...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.363096
更新日期：1994-01-01 00:00:00
abstract：:Reconstructing images of large high-contrast objects with microwave methods has proved difficult. Successful images have generally been obtained by using a priori information to constrain the image reconstruction to recover the correct electromagnetic property distribution. In these situations, the measured electric f...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.913177
更新日期：2001-02-01 00:00:00
abstract：:Dynamic contrast-enhanced magnetic resonance imaging (MRI) is a promising tool in the evaluation of tumor physiology. From rapidly acquired images and a model for contrast agent pharmacokinetics, physiological parameters are derived. One pharmacokinetic model, the tissue homogeneity model, enables estimation of both b...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2009.2016212
更新日期：2009-09-01 00:00:00
abstract：:For wrist complaints related to motion, a 2-D radiograph or CT scan of the static wrist may not always be considered diagnostic. 3-D motion imaging, i.e., multiple 3DCT scans in time (4DCT), enables quantifying carpal motion and comparing motion patterns of the affected wrist with those of the healthy contralateral si...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2018.2877503
更新日期：2019-04-01 00:00:00
abstract：:To reconstruct electrical activity in the heart from body-surface electrocardiograms (ECGs) is an ill-posed inverse problem. Electrophysiological models have been found effective in regularizing these inverse problems by incorporating a priori knowledge about how the electrical potential in the heart propagates over t...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2019.2906600
更新日期：2019-11-01 00:00:00
abstract：:The watershed transform has interesting properties that make it useful for many different image segmentation applications: it is simple and intuitive, can be parallelized, and always produces a complete division of the image. However, when applied to medical image analysis, it has important drawbacks (oversegmentation...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2004.824224
更新日期：2004-04-01 00:00:00
abstract：:The classification of 3 common breast lesions, fibroadenomas, cysts, and cancers, was achieved using computerized image analysis of tumor shape in conjunction with patient age. The process involved the digitization of 69 mammographic images using a video camera and a commercial frame grabber on a PC-based computer sys...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/42.251116
更新日期：1993-01-01 00:00:00
abstract：:Our primary motivator is the need for screening HIV+ populations in resource-constrained regions for exposure to Tuberculosis, using posteroanterior chest radiographs (CXRs). The proposed method is motivated by the observation that radiological examinations routinely conduct bilateral comparisons of the lung field. In...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2017.2775636
更新日期：2018-05-01 00:00:00
abstract：:Spectral computed tomography (CT) is a promising technique with the potential for improving lesion detection, tissue characterization, and material decomposition. In this paper, we are interested in kVp switching-based spectral CT that alternates distinct kVp X-ray transmissions during gantry rotation. This system can...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2014.2380993
更新日期：2015-03-01 00:00:00
abstract：:Segmentation-based scores play an important role in the evaluation of computational tools in medical image analysis. These scores evaluate the quality of various tasks, such as image registration and segmentation, by measuring the similarity between two binary label maps. Commonly these measurements blend two aspects ...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2012.2216281
更新日期：2012-12-01 00:00:00
abstract：:Contrast source inversion-electrical properties tomography (CSI-EPT) is an iterative reconstruction method to retrieve the electrical properties (EPs) of tissues from magnetic resonance data. The method is based on integral representations of the electromagnetic field and has been shown to allow EP reconstructions of ...
journal_title：IEEE transactions on medical imaging
pub_type： 杂志文章
doi：10.1109/TMI.2018.2816125
更新日期：2018-09-01 00:00:00
