Abstract：
PURPOSE:This article presents a computer-aided diagnosis technique for improving the accuracy of the early diagnosis of Alzheimer's disease (AD). Two hundred and ten 18F-FDG PET images from the ADNI initiative [52 normal controls (NC), 114 mild cognitive impairment (MCI), and 53 AD subjects] are studied. METHODS:The proposed methodology is based on the selection of voxels of interest using the t-test and a posterior reduction of the feature dimension using factor analysis. Factor loadings are used as features for three different classifiers: Two multivariate Gaussian mixture model, with linear and quadratic discriminant function, and a support vector machine with linear kernel. RESULTS:An accuracy rate up to 95% when NC and AD are considered and an accuracy rate up to 88% and 86% for NC-MCI and NC-MCI,AD, respectively, are obtained using SVM with linear kernel. CONCLUSIONS:Results are compared to the voxel-as-features and a PCA- based approach and the proposed methodology achieves better classification performance.
journal_name
Med Physjournal_title
Medical physicsauthors
Salas-Gonzalez D,Górriz JM,Ramírez J,Illán IA,López M,Segovia F,Chaves R,Padilla P,Puntonet CGdoi
10.1118/1.3488894subject
Has Abstractpub_date
2010-11-01 00:00:00pages
6084-95issue
11eissn
0094-2405issn
2473-4209journal_volume
37pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:Spectrally resolved bioluminescence optical tomography is an approach to recover images of, for example, Luciferase activity within a volume using multiwavelength emission data from internal bioluminescence sources. The underlying problem of uniqueness associated with nonspectrally resolved intensity-based bioluminesc...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2982138
更新日期：2008-11-01 00:00:00
abstract：:Breast-conserving surgery combined with subsequent radiation therapy is a standard procedure in breast cancer treatment. The disadvantage of whole-breast beam irradiation is that it requires 20-25 treatment days, which is inconvenient for patients with limited mobility or who reside far from the treatment center. Howe...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3243865
更新日期：2009-11-01 00:00:00
abstract：:Deformable image registration is an important tool for image-guided radiotherapy. Physics-model-based deformable image registration using finite element analysis is one of the methods currently being investigated. The calculation accuracy of finite element analysis is dependent on given boundary conditions, which are ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1774131
更新日期：2004-09-01 00:00:00
abstract：PURPOSE:To perform a comprehensive and systematic comparison of fixed-beam IMRT and volumetric modulated arc therapy (VMAT) patient-specific QA measurements for a common set of geometries using typical measurement methods. METHODS:Fixed-beam IMRT and VMAT plans were constructed for structure set geometries provided by...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4729738
更新日期：2012-07-01 00:00:00
abstract：:Recently, the clinical application of electronic portal imaging devices has enabled more frequent verification of patient setup for radiation treatment. However, the image quality has sometimes proven to be inadequate, motivating the investigation of alternative sensors with better image quality. Amorphous selenium (a...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598219
更新日期：1998-04-01 00:00:00
abstract：:Recent work has shown that there is significant uncertainty in measuring build-up doses in mega-voltage photon beams especially at high energies. In this present investigation we used a phantom-embedded extrapolation chamber (PEEC) made of Solid Water to validate Monte Carlo (MC)-calculated doses in the dose build-up ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1829401
更新日期：2005-01-01 00:00:00
abstract：PURPOSE:Micro-CT is widely used for small animal imaging in preclinical studies of cardiopulmonary disease, but further development is needed to improve spatial resolution, temporal resolution, and material contrast. We present a technique for visualizing the changing distribution of iodine in the cardiac cycle with du...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4736809
更新日期：2012-08-01 00:00:00
abstract：:Neutron energy spectra and spectra of dose deposition in tissue-equivalent material have been measured for neutron sources produced by 16-, 22-, 35-, and 45.5-MeV deuterons and 22.5-, 35-, 45-, and 65.5-MeV protons incident upon a thick beryllium target. Neutron spectra were measured using time-of-flight techniques an...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594392
更新日期：1977-05-01 00:00:00
abstract：PURPOSE:To present a system for robotic 4D ultrasound (US) imaging concurrent with radiotherapy beam delivery and estimate the proportion of liver stereotactic ablative body radiotherapy (SABR) cases in which robotic US image guidance can be deployed without interfering with clinically used VMAT beam configurations. M...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4964454
更新日期：2016-11-01 00:00:00
abstract：:For radiation dosimetry calculations of radiolabeled monoclonal antibodies, (MAB), pharmacokinetics are critical. Specifically, pharmacokinetic modeling is a useful component of estimation of cumulated activity in various source organs in the body. It is thus important to formulate general methods of pharmacokinetic m...
journal_title：Medical physics
pub_type： 杂志文章,评审
doi：10.1118/1.597047
更新日期：1993-03-01 00:00:00
abstract：:This study presents experimental results about the effective depth of penetration and about the radiofrequency (rf) power absorption in humans as a function of frequency. The frequency range investigated covers 10 up to 220 MHz. For the main part, the results were derived from bench measurements of the quality factor ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595995
更新日期：1987-11-01 00:00:00
abstract：PURPOSE:Transcranial focused ultrasound is an emerging therapeutic modality that can be used to perform noninvasive neurosurgical procedures. The current clinical transcranial phased array operates at 650 kHz, however the development of a higher frequency array would enable more precision, while reducing the risk of st...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4829510
更新日期：2013-12-01 00:00:00
abstract：:A simple method to measure the line spread function of computed tomographic scanners has been developed. The line spread function of the EMI-Scanner was measured and the MTF of the scanner was calculated. The reproducibility of the method indicated this technique could be utilized to compare the spatial resolution of ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594283
更新日期：1976-07-01 00:00:00
abstract：:A new high dose rate 20 mm 32P intravascular brachytherapy (IVB) beta source used with automated stepping has recently been introduced. The AAPM Task Group 60 recommends that beta IVB sources should have well characterized dosimetric parameters in water. In this study, Monte Carlo simulations (MCNPX v 2.4) were used t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1646651
更新日期：2004-03-01 00:00:00
abstract：PURPOSE:The purpose of this study was to investigate the impact of transverse magnetic fields on the dose response of a radiophotoluminescent glass dosimeter (RGD) in megavoltage photon beams. METHODS:The RGD relative response (i.e., RGD dose per absorbed dose to water at the midpoint of the detector in the absence of...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14054
更新日期：2020-04-01 00:00:00
abstract：PURPOSE:The Nakagami statistical model and Nakagami shape parameter m have been widely used in linear tissue characterization and preliminarily characterized the envelope distributions of nonlinear encapsulated microbubbles (EMBs). However, the Nakagami distribution of nonlinear scattering EMBs lacked a systematical in...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13833
更新日期：2019-12-01 00:00:00
abstract：:The purpose of this work is to calculate the dose perturbations due to the presence of iodine contrast media in catheter-based intravascular brachytherapy (IVBT). The EGSnrc Monte Carlo system was used to perform the calculation for the two most commonly used beta and gamma sources (90Sr and 192Ir as well as for a var...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1367279
更新日期：2001-05-01 00:00:00
abstract：:The commonly used Blunck and Leisegang electron energy-loss distribution falls off too rapidly with increasing energy loss. Also, for large thicknesses and/or low-Z media, where their distribution should approach Landau's, it normalizes to 0.92 rather than 1.0, it overestimates the number of very small energy-loss eve...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595500
更新日期：1984-05-01 00:00:00
abstract：:The objective of this work is to assess the suitability and performance of a new dosimeter system with a novel geometry for the quality assurance (QA) of volumetric modulated arc therapy (VMAT). The new dosimeter system consists of a hollow cylinder (15 and 25 cm inner and outer diameters) with 124 diodes embedded in ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3117563
更新日期：2009-05-01 00:00:00
abstract：PURPOSE:To reduce the potential of late toxicity (tissue necrosis and cognitive function loss) from brain radiotherapy, we studied a novel planning technique for MLC-equipped linear accelerators (LINACS) that reduces the high doses delivered outside the PTV, enhancing radiation dose conformity. METHODS:The feasibility...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735656
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Brachytherapy is a treatment modality which delivers large doses of radiation in a reduced number of visits. Since a small number of large dose-per-fraction is administered in high dose rate brachytherapy, ensuring the right dose is delivered is highly critical. In this work, a scintillation detector is coupled...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13508
更新日期：2019-05-01 00:00:00
abstract：PURPOSE:The aim of this study was to evaluate the suitability of several detectors for the determination of absorbed dose in bone. METHODS:Three types of ultrathin LiF-based thermoluminescent dosimeters (TLDs)-two LiF:Mg,Cu,P-based (MCP-Ns and TLD-2000F) and a (7)Li-enriched LiF:Mg,Ti-based (MTS-7s)-as well as EBT2 Ga...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4886760
更新日期：2014-08-01 00:00:00
abstract：:In patients with lymphoma, identification and quantification of the tumor extent on serial CT examinations is critical for assessing tumor response to therapy. In this paper, we present a computer method to automatically match and segment lymphomas in follow-up CT images. The method requires that target lymph nodes in...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2404617
更新日期：2007-01-01 00:00:00
abstract：PURPOSE:Intraoperative electron radiation therapy (IOERT) involves the delivery of a high radiation dose during tumor resection in a shorter time than other radiation techniques, thus improving local control of tumors. However, a linear accelerator device is needed to produce the beam safely. Mobile linear accelerators...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12482
更新日期：2017-10-01 00:00:00
abstract：PURPOSE:The authors describe a design for prepatient region of interest attenuators (ROIAs) to reduce dose area product (DAP) for clinical use. The authors describe a model to predict DAP values from x-ray technique parameters recorded during a clinical procedure for image sequences obtained in the presence or absence ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4903898
更新日期：2015-01-01 00:00:00
abstract：PURPOSE:Primary goal of this study is to select optimal registration schemes in the framework of interstitial lung disease (ILD) follow-up analysis in CT. METHODS:A set of 128 multiresolution schemes composed of multiresolution nonrigid and combinations of rigid and nonrigid registration schemes are evaluated, utilizi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4923170
更新日期：2015-08-01 00:00:00
abstract：PURPOSE:The variable resolution x-ray (VRX) CT scanner provides substantial improvement in the spatial resolution by matching the scanner's field of view (FOV) to the size of the object being imaged. Intercell x-ray cross-talk is one of the most important factors limiting the spatial resolution of the VRX detector. In ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3555035
更新日期：2011-03-01 00:00:00
abstract：PURPOSE:The absolute dose rate of the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter. The calorimetry results were compared to measurements from the existing free-air chamber, to provide a robust determination of the absolute dose in the synchrotron beam and p...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4870387
更新日期：2014-05-01 00:00:00
abstract：:The purpose of this study was to investigate the effect of z overscanning on eye lens dose and effective dose received by pediatric patients undergoing head CT examinations. A pediatric patient study was carried out to obtain the exposure parameters and data regarding the eye lens position with respect to imaged volum...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2207212
更新日期：2006-07-01 00:00:00
abstract：:The gamma index is a tool that compares a dose distribution with a reference distribution by combining dose-difference and distance-to-agreement criteria. It has been widely used for ten years despite its high computational cost. This cost is due to both a search process for each reference point and the necessity to r...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3070546
更新日期：2009-03-01 00:00:00
