Abstract：
:An automated technique for the alignment of right and left breast images has been developed for use in the computerized analysis of bilateral breast images. In this technique, the breast region is first identified in each digital mammogram by use of histogram analysis and morphological filtering operations. The anterior portions of the tracked breast border and computer-identified nipple positions are selected as landmarks for use in image registration. The paired right and left breast images, either from mediolateral oblique or craniocaudal views, are then registered relative to each other by use of a least-squares matching method. This automated alignment technique has been applied to our computerized detection scheme that employs a nonlinear bilateral-subtraction method for the initial identification of possible masses. The effectiveness of using bilateral subtraction in identifying asymmetries between corresponding right and left breast images is examined by comparing detection performances obtained with various computer-simulated misalignments of 40 pairs of clinical mammograms. Based on free-response receiver operating characteristic and regression analyses, the detection performance obtained with the automated alignment technique was found to be higher than that obtained with simulated misalignments. Detection performance decreased gradually as the amount of simulated misalignment increased. These results indicate that automatic alignment of breast images is possible and that mass-detection performance appears to improve with the inclusion of asymmetric anatomic information but is not sensitive to slight misalignment.
journal_name
Med Physjournal_title
Medical physicsauthors
Yin FF,Giger ML,Doi K,Vyborny CJ,Schmidt RAdoi
10.1118/1.597307subject
Has Abstractpub_date
1994-03-01 00:00:00pages
445-52issue
3eissn
0094-2405issn
2473-4209journal_volume
21pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract：:Effective radioimmunotherapy may depend on a priori knowledge of the radiation absorbed dose distribution obtained by trace imaging activities administered to a patient before treatment. A new, fast, and effective treatment planning approach is developed to deal with a heterogeneous activity distribution. Calculation ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.598422
更新日期：1998-11-01 00:00:00
abstract：:Radiographic magnification is often employed in mammography to improve detection of small anatomical details of clinical interest, such as microcalcifications. The image size depends on the conventional magnification factor, on the focal spot size, and on the x-ray angulation. In this paper magnification effects are i...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597288
更新日期：1994-02-01 00:00:00
abstract：:Scanning film densitometry routinely used for obtaining dosimetric information about therapy treatment beams is subject to several sources of inaccuracies. The most significant of these are described and appropriate methods of testing are presented. This establishes the need for adequate acceptance testing followed by...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595407
更新日期：1983-09-01 00:00:00
abstract：:Variations in the atomic composition, and mass and electron densities of polystyrene and polymethylmethacrylate (PMM) plastics were assessed from experimentally determined mass attenuation coefficients for 125I and 137Cs gamma rays. The means and standard deviations in the mass densities of 16 samples of PMM and 10 sa...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.594528
更新日期：1979-03-01 00:00:00
abstract：:Deionized water is commonly used to couple microwave applicators to the patient surface in the administration of local hyperthermia. Profiles of the specific absorption rate (SAR) at 1-cm depth show that deionized water coupling significantly distorts the SAR distributions of the Clini-Therm 915-MHz 10 X 10 and 15 X 1...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595881
更新日期：1986-05-01 00:00:00
abstract：PURPOSE:To evaluate the replacement of Cerrobend by copper for electron beam cutouts. METHODS:The dosimetric comparisons for circular copper-and Cerrobend-cutouts with diameters (1.0, 2.0, 3.0, 5.0, 7.5, 10.0, and 12.5 cm) were made using electron beams with energies (6, 9, 12, 16, and 20 MeV) from 3 Varian accelerato...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735336
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:This study developed and validated a Motion Artifact Quantification algorithm to automatically quantify the severity of motion artifacts on coronary computed tomography angiography (CCTA) images. The algorithm was then used to develop a Motion IQ Decision method to automatically identify whether a CCTA dataset ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13243
更新日期：2018-12-01 00:00:00
abstract：PURPOSE:Bilateral filters have been substantially exploited in numerous magnetic resonance (MR) image restoration applications for decades. Due to the deficiency of theoretical basis on the filter parameter setting, empirical manipulation with fixed values and noise variance-related adjustments has generally been emplo...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.12157
更新日期：2017-04-01 00:00:00
abstract：:Amorphous selenium (a-Se) based real-time flat-panel imagers (FPIs) are finding their way into the digital radiology department because they offer the practical advantages of digital x-ray imaging combined with an image quality that equals or outperforms that of conventional systems. The temporal imaging characteristi...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2042248
更新日期：2005-10-01 00:00:00
abstract：:As a potentially important technology for medical x-ray computed tomography (CT), lambda tomography (LT) is to reconstruct a gradient-like image only from local projection data. Based on our recently derived exact fan-beam LT formula, [H. Y. Gu and G. Wang, Int. J. Biomed. Imaging 2006(1), 1-9 (2006)] here we propose ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2348767
更新日期：2006-10-01 00:00:00
abstract：PURPOSE:To describe an efficient method for verifying the size and centering of the radiation field from the Cyberknife IRIS variable collimator with sub-millimeter accuracy using a general purpose commercially available diode array. METHODS:We present a technique using a conventional diode array (Sun Nuclear Profiler...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735220
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:Megavoltage grid therapy is currently delivered with step-and-shoot multisegment techniques or using a high attenuation block with divergent holes. However, the commercial availability of grid blocks is limited, their construction is difficult, and step-and-shoot techniques require longer treatment times and ar...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4801902
更新日期：2013-05-01 00:00:00
abstract：:The variance in the number of x-ray photons absorbed by a detector is derived from theoretical considerations. The distributions in the number of x-ray photons produced by the x-ray tube, transmitted through the patient, and absorbed by the detector are described. These distributions are compounded to yield a distribu...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595393
更新日期：1983-07-01 00:00:00
abstract：PURPOSE:Computerized liver extraction from hepatic CT images is challenging because the liver often abuts other organs of a similar density. The purpose of this study was to develop a computer-aided measurement of liver volumes in hepatic CT. METHODS:The authors developed a computerized liver extraction scheme based o...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3395579
更新日期：2010-05-01 00:00:00
abstract：PURPOSE:Mega-voltage cone-beam CT (MVCBCT) imaging can be used to monitor changes in neck flexion and calculate the true spinal cord dose during radiotherapy. To sum the dose over multiple fractions and compare with the planned dose requires deformable image registration. This study investigates the accuracy of deforma...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4734919
更新日期：2012-06-01 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：:As different types of radionuclides (e.g., 131Cs source) are introduced for clinical use in brachytherapy, the question is raised regarding whether a relatively simple method exists for the derivation of values of the half value layer (HVL) or the tenth value layer (TVL). For the radionuclide that has been clinically ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2905356
更新日期：2008-06-01 00:00:00
abstract：:The use of Kumakhov capillary optics will significantly enhance the performance of near-monochromatic, Compton backscattered x-ray programs. The Vanderbilt University Medical Free-Electron Laser Center is developing the capability to create these tunable x rays for medical imaging. The present transport has only refle...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.597218
更新日期：1994-11-01 00:00:00
abstract：PURPOSE:Image guidance is crucial for percutaneous tumor ablations, enabling accurate needle-like applicator placement into target tumors while avoiding tissues that are sensitive to injury and/or correcting needle deflection. Although ultrasound (US) is widely used for image guidance, magnetic resonance (MR) is prefer...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13958
更新日期：2020-03-01 00:00:00
abstract：:Simultaneous rest 99mTc-Sestamibi/ 123I-BMIPP cardiac SPECT imaging has the potential to replace current clinical 99mTc-Sestamibi rest/stress imaging and therefore has great potential in the case of patients with chest pain presenting to the emergency department. Separation of images of these two radionuclides is diff...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3063544
更新日期：2009-02-01 00:00:00
abstract：PURPOSE:Intracavitary accelerated partial breast irradiation (APBI) has become a popular treatment for early stage breast cancer in recent years due to its shortened course of treatment and simplified treatment planning compared to traditional external beam breast conservation therapy. However, the exit dose to the ski...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3429089
更新日期：2010-06-01 00:00:00
abstract：PURPOSE:Imaging the knee under realistic load-bearing conditions can be carried out in a horizontal plane using a C-arm CT scanner. Human subjects can be scanned in a standing position and acquired data successfully reconstructed. However, reconstructing this data is a challenge due to significant artifacts that are in...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4736213
更新日期：2012-06-01 00:00:00
abstract：:A nondestructive and noninvasive method for numeric characterization (quantification) of the structural composition of human bone tissue has been developed and tested. In order to quantify and to compare the structural composition of bones from 2D computed tomography (CT) images acquired at different skeletal location...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.2336501
更新日期：2006-10-01 00:00:00
abstract：PURPOSE:To measure the calibration curves of EBT3 dosimetry films in photon and proton beams and to quantify the related uncertainties from one beam type to another. METHODS:EBT3 Gafchromic films have similar properties than EBT2 with a symmetric construction and a matte polyester substrate to prevent Newton's ring ar...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4735176
更新日期：2012-06-01 00:00:00
abstract：PURPOSE:The purpose of this paper was to present a method of determining the dose profile of the beam bow-tie filter (BTF) without the need for fixing the x ray tube in a position or using special instruments or dosimeters other than the ordinary types of ion chambers used for CT dosimetry (e.g., Farmer chamber). METH...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.13203
更新日期：2018-11-01 00:00:00
abstract：PURPOSE:As radiation therapy evolves toward more adaptive techniques, image guidance plays an increasingly important role, not only in patient setup but also in monitoring the delivered dose and adapting the treatment to patient changes. This study aimed to validate a method for evaluation of delivered intensity modula...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.4903292
更新日期：2015-01-01 00:00:00
abstract：:Monte Carlo calculations have been made to determine the energy delivered to a phantom by neutrons escaping from the head of a Varian Clinac 35 medical accelerator at an SSD of 1 m. The energy was sorted into two regions: inside and outside a volume defined by a circular beam of area 100 and 600 cm2. For the two beam ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.595067
更新日期：1982-01-01 00:00:00
abstract：:The focal spot of a linear accelerator is often considered to have a fully stable position. In practice, however, the beam control loop of a linear accelerator needs to stabilize after the beam is turned on. As a result, some motion of the focal spot might occur during the start-up phase of irradiation. When acquiring...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.1576229
更新日期：2003-06-01 00:00:00
abstract：PURPOSE:To develop an automatic knot placement algorithm to enable the use of NonUniform Rational B-Splines (NURBS) in deformable image registration. METHODS:The authors developed a two-step approach to fit a known displacement vector field (DVF). An initial fit was made with uniform knot spacing. The error generated ...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1118/1.3609416
更新日期：2011-08-01 00:00:00
abstract：PURPOSE:A dosimetry evaluation model for treatment planning of esophageal radiation therapy is developed using a deep learning model. The model predicts dose volume histogram (DVH) from distance to target histogram (DTH) based on stacked de-noise auto-encoder (SDAE) and one-dimensional convolutional network (1D-CN). M...
journal_title：Medical physics
pub_type： 杂志文章
doi：10.1002/mp.14434
更新日期：2020-10-01 00:00:00
