Abstract：
:The purposes of this research are to investigate the effectiveness of our novel image features for segmentation of anatomic regions such as the lungs and the mediastinum in chest radiographs and to develop an automatic computerized method for image processing. A total of 85 screening chest radiographs from Johns Hopkins University Hospital were digitized to 2 K by 2.5 K pixels with 12 bit gray scale. To reduce the amount of information, the images were smoothed and subsampled to 256 by 310 pixels with 8 bit. The determination approach consists of classifying each pixel into two anatomic classes (lung and others) on the basis of several image features: (1) relative pixel address (Rx, Ry) based on lung edges extracted through image processing using profile, (2) density normalized from lungs and mediastinum density, and (3) histogram equalized entropy. The combinations of image features were evaluated using an adaptive-sized hybrid neural network consisting of an input, a hidden, and an output layer. Fourteen images were used for the training of the neural network and the remaining 71 images for testing. Using four features of relative address (Rx, Ry), normalized density, and histogram equalized entropy, the neural networks classified lungs at 92% accuracy against test images following the same rules as for the training images.
journal_name
Med Physjournal_title
Medical physicsauthors
Tsujii O,Freedman MT,Mun SKdoi
10.1118/1.598277subject
Has Abstractpub_date
1998-06-01 00:00:00pages
998-1007issue
6eissn
0094-2405issn
2473-4209journal_volume
25pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:Nuclear Magnetic Resonance (NMR) permits the noninvasive measurement of blood flow signals unimpaired by clothes, bandages, casts, etc. The cylindrical crossed-coil NMR blood flowmeter was used to measure blood flow through a cross-section of the human forearm. Two calibration procedures are described: one for pulsati...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594989
更新日期：1981-07-01 00:00:00
abstract：PURPOSE:To Validate Brainlab-ExacTrac IGRT with Dot-Decimal electron compensator(BolusECT) for accurate patient positioning. METHODS:Dot-Decimal electron compensators(BolusECT) are used to achieve conformal dose distributions and greater sparing to normal structures for cases with varying patient contours and treated ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734881
更新日期：2012-06-01 00:00:00
abstract：:The fast imaging method named skipped phase encoding and edge deghosting (SPEED) has been demonstrated to reduce scan time considerably with typical magnetic resonance imaging data. In this work, SPEED is simplified with improved efficiency to accelerate the scan of sparse objects; we refer to this method as S-SPEED. ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2750966
更新日期：2007-08-01 00:00:00
abstract：:Conventional chest radiography is limited by the presence of scattered radiation and the small useful exposure range of radiographic film. A computer-assisted scanning system to minimize these two effects is outlined. The system uses a small beam of radiation swept over the patient's chest in a raster pattern to expos...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595327
更新日期：1983-09-01 00:00:00
abstract：PURPOSE:Current on-board imaging systems commonly used by modern linear accelerators (LINACs) have a limited field of view (FOV) for a cone-beam CT (CBCT) scan, which is typically less than 50 cm. Consequently, truncation artifacts often occur for large patients. The goal of this work is to investigate a novel method t...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3514130
更新日期：2010-12-01 00:00:00
abstract：PURPOSE:To determine the feasibility and potential utility of cone beam CT on breast biopsies. METHODS:CBCT simulations were done with a setup which emulates an MX-20 digital specimen radiography system (Faxitron X-Ray Corporation, Chicago, IL), albeit a DQE = 1 was assumed. The phantom consisted of a 5mm diameter cyl...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4740191
更新日期：2012-07-01 00:00:00
abstract：:Manganese (Mn) is an essential nutrient for growth and development. Unfortunately, overexposure can lead to neurological damage, which is manifested as a movement disorder marked by tremors. Preclinical symptoms have been found in populations occupationally exposed to the element, and it is suggested that in late stag...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1517613
更新日期：2002-11-01 00:00:00
abstract：PURPOSE:To automatically and efficiently segment the lesion area of the colonoscopy polyp image, a polyp segmentation method has been presented. METHODS:An ensemble model of pretrained convolutional neural networks was proposed, using Unet-VGG, SegNet-VGG, and PSPNet. Firstly, the Unet-VGG is obtained by the first 10 ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13865
更新日期：2019-12-01 00:00:00
abstract：:The validity of conclusions drawn from multi-institutional radiotherapy studies is dependent upon the degree to which participating hospitals adhere to study requirements. A major effort undertaken by the Quality Assurance Review Center (QARC) assesses whether or not patient data which are deemed evaluable actually co...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595221
更新日期：1982-03-01 00:00:00
abstract：:A combination of Monte Carlo, convolution, and experimental techniques have been used to investigate bremsstrahlung production at 50 MeV in full-range targets to produce narrow elementary photon beams for scanning. Calculations using the ITS 3.0 Monte Carlo system for various target designs, including particle transpo...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597681
更新日期：1996-04-01 00:00:00
abstract：PURPOSE:To develop a hypothesis-generating framework for automatic extraction of dose-outcome relationships from an in-house, analytic oncology database. METHODS:Dose-volume histograms (DVH) and clinical outcomes have been routinely stored to the authors' database for 684 head and neck cancer patients treated from 200...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4922686
更新日期：2015-07-01 00:00:00
abstract：PURPOSE:Statistical modeling of an ultrasound backscattered echo envelope is used for tissue characterization. However, in the presence of complex structures within the analyzed area, estimation of parameters is disturbed and unreliable, e.g., in the case of breast tumor classification. In order to improve the differen...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4962928
更新日期：2016-10-01 00:00:00
abstract：:Interchange or transfer of radiographic techniques through measurement of penetration quality is discussed. The usefulness of this achievement is verified using an aluminum step wedge. Also, the procedure described provides a method for performance evaluation of kVp compensation on diagnostic x-ray installations. ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594156
更新日期：1975-01-01 00:00:00
abstract：:The customization of brachytherapy dose distributions for gynecologic malignancies is limited by the spatial positioning of the applicators. We tested the hypothesis that applicator-guided intensity modulated radiation therapy (AGIMRT) has the potential to deliver highly conformal dose distributions to cervical tumors...
journal_title：Medical physics
pub_type： 临床试验,杂志文章
doi：10.1118/1.1645678
更新日期：2004-04-01 00:00:00
abstract：PURPOSE:In this article, the authors studied the feasibility of estimating regional mechanical properties in cerebral aneurysms, integrating information extracted from imaging and physiological data with generic computational models of the arterial wall behavior. METHODS:A data assimilation framework was developed to ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3355933
更新日期：2010-04-01 00:00:00
abstract：:In order to use negative pions for the treatment of large deep-seated tumors in radiotherapy, it is necessary to produce depth-dose distributions tailored to specific shapes. We present here a method of beam shaping which utilizes a fluid-filled piston having a programmable, computer-controlled, time-dependent thickne...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594313
更新日期：1977-09-01 00:00:00
abstract：:A simple noninvasive method is described for determining the backscatter to a monitor chamber of a medical accelerator based on the measurement of charge deposited in the target. This method is compared quantitatively to the more elaborate telescopic method for photon beams of 6 MV and 15 MV on linear accelerators hav...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598203
更新日期：1998-03-01 00:00:00
abstract：:The purpose of this work is to compare the efficacy of mathematical models in predicting the occurrence of radiotherapy-induced left ventricular perfusion defects assessed using single-photon emission computed tomography (SPECT). The basis of this study is data from 73 left-sided breast/ chestwall patients treated wit...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1823571
更新日期：2005-01-01 00:00:00
abstract：:The authors are investigating the concept of a direct-conversion flat-panel imager with avalanche gain for low-dose x-ray imaging. It consists of an amorphous selenium (a-Se) photoconductor partitioned into a thick drift region for x-ray-to-charge conversion and a relatively thin region called high-gain avalanche rush...
journal_title：Medical physics
pub_type： 杂志文章,评审
doi：10.1118/1.3002314
更新日期：2008-12-01 00:00:00
abstract：:Three-dimensional water phantoms are routinely used when acquiring the data necessary to commission medical linear accelerators. A new water phantom controller has been developed at our institution that is unique in several aspects. The water phantom controller is based on an IBM XT compatible computer. This has been ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.596414
更新日期：1989-01-01 00:00:00
abstract：PURPOSE:Intensity-modulated proton therapy (IMPT) is known to be sensitive to patient setup and range uncertainty issues. Multiple robust optimization methods have been developed to mitigate the impact of these uncertainties. Here, we propose a new robust optimization method, which provides an alternative way of robust...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13276
更新日期：2019-01-01 00:00:00
abstract：PURPOSE:The purpose of this work is twofold: First, to characterize the artifacts occurring in helical 4D-CT imaging; second, to propose a method that can automatically identify the artifacts in 4D-CT images. The authors have designed a process that can automatically identify the artifacts in 4D-CT images, which may be...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3553556
更新日期：2011-04-01 00:00:00
abstract：PURPOSE:The Imaging and Radiation Oncology Core Houston (IROC-H) (formerly the Radiological Physics Center) has reported varying levels of agreement in their anthropomorphic phantom audits. There is reason to believe one source of error in this observed disagreement is the accuracy of the dose calculation algorithms an...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12426
更新日期：2017-09-01 00:00:00
abstract：PURPOSE:The treatment of moving targets with scanned proton beams is challenging. For motion mitigation, an Active Breathing Coordinator (ABC) can be used to assist breath-holding. The delivery of pencil beam scanning fields often exceeds feasible breath-hold durations, requiring high breath-hold reproducibility. We ev...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13195
更新日期：2018-12-01 00:00:00
abstract：PURPOSE:Scatter is a major factor degrading the image quality of cone beam computed tomography (CBCT). Conventional scatter correction strategies require handcrafted analytical models with ad hoc assumptions, which often leads to less accurate scatter removal. This study aims to develop an effective scatter correction ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13583
更新日期：2019-07-01 00:00:00
abstract：:Current generation electronic portal imaging devices (EPID) contain a 1.0 mm copper conversion plate to increase detection efficiency of a therapeutic megavoltage spectrum. When using these EPIDs for low-Z target imaging, the conversion plate largely attenuates the large populations of diagnostic energy photons, there...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4740105
更新日期：2012-07-01 00:00:00
abstract：PURPOSE:The purpose of the present study was to perform an analysis of the changes in the dynamic seroma cavity based on fiducial markers in early stage breast cancer patients treated with accelerated partial breast irradiation (APBI) using three-dimensional conformal external beam radiotherapy (3D-CRT). METHODS:A pro...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4788644
更新日期：2013-02-01 00:00:00
abstract：PURPOSE:Repeated brain MRI scans are performed in many clinical scenarios, such as follow up of patients with tumors and therapy response assessment. In this paper, the authors show an approach to utilize former scans of the patient for the acceleration of repeated MRI scans. METHODS:The proposed approach utilizes the...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4928148
更新日期：2015-09-01 00:00:00
abstract：:A study of the objective imaging characteristics of a new asymmetric screen-film system is presented herein. The system is characterized by high x-ray absorption asymmetric screens, and a low-noise, high-contrast asymmetric film having near-zero crossover. Comparisons are made with the imaging characteristics of two w...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597407
更新日期：1994-09-01 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
