Abstract:
PURPOSE:Automated detection of solitary pulmonary nodules using positron emission tomography (PET) and computed tomography (CT) images shows good sensitivity; however, it is difficult to detect nodules in contact with normal organs, and additional efforts are needed so that the number of false positives (FPs) can be further reduced. In this paper, the authors propose an improved FP-reduction method for the detection of pulmonary nodules in PET/CT images by means of convolutional neural networks (CNNs). METHODS:The overall scheme detects pulmonary nodules using both CT and PET images. In the CT images, a massive region is first detected using an active contour filter, which is a type of contrast enhancement filter that has a deformable kernel shape. Subsequently, high-uptake regions detected by the PET images are merged with the regions detected by the CT images. FP candidates are eliminated using an ensemble method; it consists of two feature extractions, one by shape/metabolic feature analysis and the other by a CNN, followed by a two-step classifier, one step being rule based and the other being based on support vector machines. RESULTS:The authors evaluated the detection performance using 104 PET/CT images collected by a cancer-screening program. The sensitivity in detecting candidates at an initial stage was 97.2%, with 72.8 FPs/case. After performing the proposed FP-reduction method, the sensitivity of detection was 90.1%, with 4.9 FPs/case; the proposed method eliminated approximately half the FPs existing in the previous study. CONCLUSIONS:An improved FP-reduction scheme using CNN technique has been developed for the detection of pulmonary nodules in PET/CT images. The authors' ensemble FP-reduction method eliminated 93% of the FPs; their proposed method using CNN technique eliminates approximately half the FPs existing in the previous study. These results indicate that their method may be useful in the computer-aided detection of pulmonary nodules using PET/CT images.
journal_name
Med Physjournal_title
Medical physicsauthors
Teramoto A,Fujita H,Yamamuro O,Tamaki Tdoi
10.1118/1.4948498subject
Has Abstractpub_date
2016-06-01 00:00:00pages
2821-2827issue
6eissn
0094-2405issn
2473-4209journal_volume
43pub_type
杂志文章相关文献
MEDICAL PHYSICS文献大全abstract::In intensity modulated radiation treatments (IMRT), the position of the field edges and the modulation within the beam are often achieved with a multileaf collimator (MLC). During the MLC calibration process, due to the finite accuracy of leaf position measurements, a systematic error may be introduced to leaf positio...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2335490
更新日期:2006-09-01 00:00:00
abstract:PURPOSE:Computational models are widely used during the design and characterization of microwave ablation (MWA) devices, and have been proposed for pretreatment planning. Our objective was to assess three-dimensional (3D) transient temperature and ablation profiles predicted by MWA computational models with temperature...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14318
更新日期:2020-09-01 00:00:00
abstract::Results of a human observer performance study using a new ultrasound contrast-detail (CD) phantom are reported. The new phantom allows estimates of the fundamental statistical uncertainties involved in CD analysis. Results of these experiments show that observers generally considered to be "trained" require experience...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.597147
更新日期:1993-01-01 00:00:00
abstract:PURPOSE:The segmentation accuracy of medical images was improved by increasing the number of training samples using a local image warping technique. The performance of the proposed method was evaluated in the segmentation of breast masses, prostate and brain tumors, and lung nodules. METHODS:We propose a simple data a...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14651
更新日期:2020-12-10 00:00:00
abstract:PURPOSE:Computed tomography (CT) is one of the most used imaging modalities for imaging both symptomatic and asymptomatic patients. However, because of the high demand for lower radiation dose during CT scans, the reconstructed image can suffer from noise and artifacts due to the trade-off between the image quality and...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12523
更新日期:2017-10-01 00:00:00
abstract::Proton beams offer several advantages over conventional radiation techniques for treating cancer and other diseases. These advantages might be negated if the leakage and scatter radiation from the beamline and patient are too large. Although the leakage and scatter radiation for the double scattering proton beamlines ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2805086
更新日期:2008-01-01 00:00:00
abstract::Current edge detection methods used to determine coronary artery dimensions from digital (DSA) images suffer a strong dependence on the system's modulation transfer function (MTF). The videodensitometric algorithms are less sensitive to MTF blurring, yet still result in an overestimation of the vessel size of 10% to 2...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.596370
更新日期:1989-03-01 00:00:00
abstract::With the increased sophistication of lasers used for patient positioning in radiotherapy comes increased possibilities for mistakes in installing the lasers, which can result in serious patient positioning errors. Two principles must be followed when mounting cross-projecting lasers: (1) the horizontal line must be on...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.594960
更新日期:1981-05-01 00:00:00
abstract::Imaging parameters associated with a clinical magnetic resonance imaging (MRI) system, evaluated with the use of simple and inexpensive phantoms, are described in evaluation of a clinical MRI system. Images, obtained with a Diasonics 0.35-T MRI system using an elliptical whole-body radio frequency coil, are presented ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.595894
更新日期:1986-07-01 00:00:00
abstract::Electron spectral reconstruction of medical accelerators from measured depth doses is a practical method for providing the input initial phase space distribution at the patient surface that is required by Monte Carlo treatment planning systems. The posed inverse problem of spectral reconstruction is ill conditioned an...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2161404
更新日期:2006-02-01 00:00:00
abstract:PURPOSE:To achieve more translatable preclinical research results, small animal irradiation needs to more closely simulate human radiotherapy. Although the clinical gold standard is intensity-modulated radiation therapy (IMRT), the direct translation of this method for small animals is impractical. In this study we des...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.13872
更新日期:2019-12-01 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:Real-time adaptive planning and treatment has been infeasible due in part to its high computational complexity. There have been many recent efforts to utilize graphics processing units (GPUs) to accelerate the computational performance and dose accuracy in radiation therapy. Data structure and memory access pat...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4895822
更新日期:2014-10-01 00:00:00
abstract::Respiration can cause tumors in the thorax or abdomen to move by as much as 3 cm; this movement can adversely affect the planning and delivery of radiation treatment. Several techniques have been used to compensate for respiratory motion, but all have shortcomings. Manufacturers of computed tomography (CT) equipment h...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2044427
更新日期:2006-01-01 00:00:00
abstract:PURPOSE:To investigate the accuracy of output factor measurements using a commercial (Exradin W1, SI) and a prototype, "in-house" developed, plastic scintillation dosimeter (PSD) in small photon fields. METHODS:Repetitive detector-specific output factor OFdet measurements were performed in water (parallel to the CAX) ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.12064
更新日期:2017-02-01 00:00:00
abstract::Age-related macular degeneration (AMD) is a leading cause for vision loss for people over the age of 65 in the United States and a major health problem worldwide. Research for new treatments of the wet form of the disease using kilovoltage stereotactic radiosurgery is currently underway at Oraya Therapeutics, Inc. In ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3168554
更新日期:2009-08-01 00:00:00
abstract::Multislice helical computed tomography (CT) is a promising noninvasive technique for coronary artery imaging. Various factors can cause inconsistencies in cardiac CT data, which can result in degraded image quality. These inconsistencies may be the result of the patient physiology (e.g., heart rate variations), the na...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2163247
更新日期:2006-02-01 00:00:00
abstract::The dissemination of scientific advances has changed little since the first peer-reviewed journal was published in 1665 - that is, until this past decade. The print journal, delivered by mail and stored on office shelves and in library reading rooms around the world, has been transformed by immediate, on-demand access...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4736173
更新日期:2012-06-01 00:00:00
abstract:PURPOSE:To generate hybrid VMAT-IMRT treatment plans by utilizing an IMRT beam-angle-optimality (BAO) search under a commercially available TPS without the aid of custom optimization software or high performance computing. METHODS:The high dose modulation provided by IMRT beams can be exploited to improve the quality ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4735712
更新日期:2012-06-01 00:00:00
abstract::Soft-tissue detectability in cone-beam computed tomography (CBCT) was evaluated via two-alternative forced-choice (2AFC) tests. Investigations included the dependence of detectability on radiation dose, the influence of the asymmetric three-dimensional (3D) noise-power spectrum (NPS) in axial and sagittal or coronal p...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2790586
更新日期:2007-11-01 00:00:00
abstract:PURPOSE:The purpose of this study was to investigate the potential of MR-guided pulsed focused ultrasound (pFUS) for the enhancement of drug uptake in prostate tumors in vivo using doxorubicin (Dox). METHODS:An antitumor drug Dox, an orthotopic animal prostate tumor model using human prostate cancer, LNCaP cell line, ...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4705346
更新日期:2012-05-01 00:00:00
abstract:PURPOSE:The need for an accurate lesion segmentation tool in 18FDG PET is a prerequisite for the estimation of lesion response to therapy, for radionuclide dosimetry, and for the application of 18FDG PET to radiotherapy planning. In this work, the authors have developed an iterative method based on a mathematical fit d...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3222732
更新日期:2009-10-01 00:00:00
abstract::The image display is an important component of the Picture Archiving and Communication System (PACS) and of digital imaging in general. In this paper, we assess the display performance of 32 different flat panel LCD devices, in terms of their reflection, luminance response, luminance uniformity, resolution, noise, vei...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1764946
更新日期:2004-07-01 00:00:00
abstract:PURPOSE:The number of pencil beam scanned proton therapy (PBS-PT) facilities equipped with cone-beam computed tomography (CBCT) imaging treating thoracic indications is constantly rising. To enable daily internal motion monitoring during PBS-PT treatments of thoracic tumors, we assess the performance of Motion-Aware Re...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1002/mp.14521
更新日期:2020-12-01 00:00:00
abstract::Use of dynamic multileaf collimation (DMLC) for intensity modulated radiation therapy (IMRT) is accelerating. Delivery systems have the ailment of interleaf leakage (IL). This is compounded by the inefficiency of IMRT delivery, estimated to be a factor of 5 for DMLC. With IL on the order of 4%, it is possible to deliv...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.1388216
更新日期:2001-08-01 00:00:00
abstract:PURPOSE:The nonlocal influence from distant magnetization will affect the magnetic field at a voxel in question. Existing reports on BOLD simulation only consider vasculature inside a single voxel, thus omitting the contribution from the surrounding regions. In this article, the authors study the effect of the surround...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3366251
更新日期:2010-04-01 00:00:00
abstract::Transthoracic electrical impedance Z consists of a constant baseline component Z0 and the time variable component delta Z such that Z = Z0 + delta Z. The first time derivative of Z has a negative peak, the magnitude of which is (dZ/dt)min. Measurements of 170 volunteers show that (dZ/dt)min is a function of the consta...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.594910
更新日期:1981-01-01 00:00:00
abstract:PURPOSE:Respiration-induced intrafraction target motion is a concern in liver cancer radiotherapy, especially in stereotactic body radiotherapy (SBRT), and therefore, verification of its motion is necessary. An effective means to localize the liver cancer is to insert metal fiducial markers to or near the tumor with si...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.3544369
更新日期:2011-02-01 00:00:00
abstract:PURPOSE:Radiochromic film provides dose measurement at high spatial resolution, but often is not preferred for routine evaluation of patient-specific intensity modulated radiation therapy (IMRT) plans owing to ease-of-use factors. The authors have established an efficient protocol that combines calibration and measurem...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.4754797
更新日期:2012-10-01 00:00:00
abstract::Mammography is the most effective method for breast cancer screening available today. However, the low positive predictive value of breast biopsy resulting from mammogram interpretation leads to approximately 70% unnecessary biopsies with benign outcomes. To reduce the high number of unnecessary breast biopsies, sever...
journal_title:Medical physics
pub_type: 杂志文章
doi:10.1118/1.2786864
更新日期:2007-11-01 00:00:00