Abstract:
:Continuous arterial spin labeling (CASL) is a technique for performing quantitative perfusion measurements without the need for exogenous contrast agent administration. This technique has seen limited use in the clinic due to problems of poor sensitivity and the potential for artifacts. In addition, CASL requires the application of long-duration radiofrequency pulses and the acquisition of a large number of images, which can cause difficulties when implemented on commercial MR scanners. This work details our experience in implementing CASL on a commercial MR scanner for the measurement of cerebral blood flow, including pitfalls regarding hardware, radiofrequency energy deposition, and practical application in human subjects. Results of studies to determine the optimal acquisition procedures are also presented.
journal_name
J Appl Clin Med Physjournal_title
Journal of applied clinical medical physicsauthors
Steger TR,Jackson EFdoi
10.1120/jacmp.v6i1.2068keywords:
subject
Has Abstractpub_date
2005-01-01 00:00:00pages
94-100issue
1issn
1526-9914journal_volume
6pub_type
临床试验,杂志文章abstract:INTRODUCTION:Aim of this study is to dosimetrically characterize a new inorganic scintillator designed for magnetic resonance-guided radiotherapy (MRgRT) in the presence of 0.35 tesla magnetic field (B). METHODS:The detector was characterized in terms of signal to noise ratio (SNR), reproducibility, dose linearity, an...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13012
更新日期:2020-09-01 00:00:00
abstract:PURPOSE:Multiple metrics are proposed to characterize and compare the complexity of helical tomotherapy (HT) plans created for different treatment sites. METHODS:A cohort composed of 208 HT plans from head and neck (105), prostate (51) and brain (52) tumor sites was considered. For each plan, 14 complexity metrics wer...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12895
更新日期:2020-07-01 00:00:00
abstract:PURPOSE:To evaluate the quality of patient-specific complicated treatment plans, including commercialized treatment planning systems (TPS) and commissioned beam data, we developed a process of quality assurance (QA) using a Monte Carlo (MC) platform. Specifically, we constructed an interface system that automatically c...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12718
更新日期:2019-10-01 00:00:00
abstract::Radiochromic film has become an important tool to verify dose distributions in highly conformal radiation therapy such as IMRT. Recently, a new generation of these films, EBT3, has become available. EBT3 has the same composition and thickness of the sensitive layer of the previous EBT2 films, but its symmetric layer c...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i2.4111
更新日期:2013-03-04 00:00:00
abstract:PURPOSE:To establish a streamlined end-to-end test of a 6 degrees-of-freedom (6DoF) robotic table using a 3D printed phantom for periodic quality assurance. METHODS:A 3D printed phantom was fabricated with translational and rotational offsets and an imbedded central ball-bearing (BB). The phantom underwent each step o...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12227
更新日期:2018-01-01 00:00:00
abstract::In Winston-Lutz (WL) tests, the isocenter of a linear accelerator (linac) is determined as the intersection of radiation central axes (CAX) from multiple gantry, collimator, and couch angles. It is well known that the CAX can wobble due to mechanical imperfections of the linac. Previous studies suggested that the wobb...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i1.5792
更新日期:2016-01-08 00:00:00
abstract::The objectives of this project are to quantify the dose reduction effect provided by a lead shield for patients with cardiac implantable electronic devices (CIED) during a clinically realistic radiation treatment on phantom and to provide a simple model of dose estimation to predict dose received by CIED in a wide ran...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i6.5317
更新日期:2015-11-08 00:00:00
abstract::Increasingly, the advent of multislice CT scanners, volume CT scanners, and total body spiral acquisition modes has led to the use of Multi Planar Reconstruction and 3D datasets. In considering 3D resolution properties of a CT system it is important to note that both the in-plane (x,y) and z-axis (slice thickness) inf...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i5.6294
更新日期:2016-09-08 00:00:00
abstract::This study details the generation, verification, and implementation of a treatment planning system (TPS) couch top model for patient support system used in conjunction with a dedicated stereotactic linear accelerator. Couch top model was created within the TPS using CT simulation images of the kVue Calpyso-compatible ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i4.5441
更新日期:2015-07-08 00:00:00
abstract::The purpose was to study correlations amongst IMRT DVH evaluation points and how their relaxation impacts the overall plan. 100 head-and-neck cancer cases, using the Eclipse treatment planning system with the same protocol, are statisti-cally analyzed for PTV, brainstem, and spinal cord. To measure variations amongst ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i6.6411
更新日期:2016-11-08 00:00:00
abstract::In this work, leakage radiation from EA200 series electron applicators on Siemens Primus accelerators is quantified, and its penetration ability in water and/or the shielding material Xenolite-NL established. Initially, measurement of leakage from 10 x 10 - 25 x 25 cm2 applicators was performed as a function of height...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v11i3.3105
更新日期:2010-06-15 00:00:00
abstract::The purpose of this study was to implement full/half bowtie filter models in a com-mercial treatment planning system (TPS) to calculate kilovoltage (kV) cone-beam CT (CBCT) doses of Varian On-Board Imager (OBI) kV X-ray imaging system. The full/half bowtie filter models were created as compensators in Pinnacle TPS usi...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v17i2.5988
更新日期:2016-03-08 00:00:00
abstract:PURPOSE:Prescription practice in SRS plans for brain tumors differs significantly for different modalities. In this retrospective study, the strategies to optimize SRS plans for brain tumors with volumetric arc therapy (VMAT) were presented. METHODS:Fifty clinically treated cases were stratified by the maximum target ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12818
更新日期:2020-03-01 00:00:00
abstract::We have investigated the combined effect of tissue heterogeneity and its variation associated with geometric error in stereotactic body radiotherapy (SBRT) for lung cancer. The treatment plans for eight lung cancer patients were calculated using effective path length (EPL) correction and Monte Carlo (MC) algorithms, w...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i5.5397
更新日期:2015-09-08 00:00:00
abstract::We report on initial patient studies to evaluate the performance of a commercial respiratory gating radiotherapy system. The system uses a breathing monitor, consisting of a video camera and passive infrared reflective markers placed on the patient's thorax, to synchronize radiation from a linear accelerator with the ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v2i4.2596
更新日期:2001-10-01 00:00:00
abstract::True 3D CT dataset for treatment planning of an oversized patient is difficult to acquire due to the bore size and field of view (FOV) reconstruction. This project aims to provide a simple approach to reconstruct true CT data for oversize patients using CT scanner with limited FOV by acquiring double partial CT (left ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i2.3629
更新日期:2012-03-08 00:00:00
abstract::A custom-made computer program, SWIMRT, to construct "multileaf collimator (MLC) machine" file for intensity-modulated radiotherapy (IMRT) fluence maps was developed using MATLAB and the sliding window algorithm. The user can either import a fluence map with a graphical file format created by an external treatment-pla...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v7i2.2231
更新日期:2006-05-25 00:00:00
abstract::The QFix EncompassTM stereotactic radiosurgery (SRS) immobilization system consists of a thermoplastic mask that attaches to the couch insert to immobilize patients treated with intracranial SRS. This study evaluates the dosimetric impact and verifies a vendor provided treatment planning system (TPS) model in the Ecli...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12387
更新日期:2018-07-01 00:00:00
abstract::Documentation is a required component of a residency program, but can be difficult to collect and disseminate, resulting in minimal utilization by residents and faculty. The purpose of this work is to adapt a commercially-available Web-based medical residency management system to improve the learning experience by eff...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i6.4866
更新日期:2014-11-08 00:00:00
abstract::A method to evaluate the electron beam energy constancy by employing the computed radiography (CR) system has been developed. In this method, a right triangular plastic wedge is used to produce a curve of the CR storage phosphor plate signal versus the wedge thickness. The curve, which resembles the percentage depth i...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i4.2911
更新日期:2009-10-15 00:00:00
abstract:PURPOSE:To investigate the differences between internal target volumes (ITVs) contoured on the simulation 4DCT and daily 4DCBCT images for lung cancer patients treated with stereotactic body radiotherapy (SBRT) and determine the dose delivered on 4D planning technique. METHODS:For nine patients, 4DCBCTs were acquired ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13041
更新日期:2020-10-12 00:00:00
abstract::The image-guided radiotherapy technique (IGRT) makes use of imaging devices to verify the positions of the target volume and organs at risk during the treatment sessions. In this work we evaluate the image quality provided by an imaging system based on a kilovoltage cone-beam CT, and explore its ability to perform IGR...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v14i1.3888
更新日期:2013-01-07 00:00:00
abstract::Intraoperative electron radiation therapy (IOERT) cannot usually benefit, as conventional external radiotherapy, from software systems of treatment planning based on computed tomography and from common dose verify procedures. For this reason, in vivo film dosimetry (IVFD) proves to be an effective methodology to evalu...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v16i1.5065
更新日期:2014-01-08 00:00:00
abstract::The increasing popularity of intensity-modulated arc therapy (IMAT) treatments requires specifically designed linac quality assurance (QA) programs. Gantry angle is one of the parameters that has a major effect on the outcome of IMAT treatments since dose reconstruction for patient-specific QA relies on the gantry ang...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v13i6.3981
更新日期:2012-11-08 00:00:00
abstract::A new calculation algorithm has been developed for independently verifying doses calculated by the TomoTherapy Hi.Art treatment planning system (TPS). The algorithm is designed to confirm the dose to a point in a high dose, low dose-gradient region. Patient data used by the algorithm include the radiological depth to ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i1.2772
更新日期:2009-02-05 00:00:00
abstract:PURPOSE:The purpose of this study was to introduce a new algorithm for automated measurement of the modulation transfer function (MTF) using an edge of a readily available phantom and to evaluate the effect of reconstruction filter and field of view (FOV) on the spatial resolution in the CT images. METHODS:Our automat...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12476
更新日期:2018-11-01 00:00:00
abstract::Traditional quality assurance checks of a patient's radiation therapy plan involve printing out treatment parameters from the treatment planning system and the "record and verify" (R&V) system and visually checking the information for one-to-one correspondence. In a paperless environment, one can automate this process...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v10i1.2905
更新日期:2009-01-27 00:00:00
abstract::Using a plane-parallel advanced Markus ionization chamber and a stack of water-equivalent solid phantom blocks, percentage surface and build-up doses of Elekta 6 MV flattening filter (FF) and flattening-filter-free (FFF) beams were measured as a function of the phantom depth for field sizes ranging from 2 × 2 to 10 × ...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.13094
更新日期:2020-12-01 00:00:00
abstract::Breast treatments are becoming increasingly complex as the use of modulated and partial breast therapies becomes more prevalent. These methods are predicated on accurate and precise positioning for treatment. However, the ability to quantify intrafraction motion has been limited by the excessive dose that would result...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1120/jacmp.v15i6.4957
更新日期:2014-11-08 00:00:00
abstract::This work describes the use of 3D printing technology to create individualized boluses for patients treated with electron beam therapy for skin lesions of the eye canthi. It aimed to demonstrate the effectiveness of 3D-printed over manually fabricated paraffin boluses. The study involved 11 patients for whom the const...
journal_title:Journal of applied clinical medical physics
pub_type: 杂志文章
doi:10.1002/acm2.12013
更新日期:2017-01-01 00:00:00