keyword
MENU ▼
Read by QxMD icon Read
search

4D CT

keyword
https://www.readbyqxmd.com/read/28440669/can-multiphase-dynamic-ct-angiography-provide-a-better-assessment-of-aortic-dissection-compared-with-the-standard-triphasic-protocol
#1
Chun-Yan Lu, Yi-Ke Diao, Ying-Qiang Guo, Xiao-Hui Zhang, Hong-Li Bai, Zhen-Lin Li
Background Acute aortic dissection (AD) is a life-threatening medical emergency. It has been debated whether the multiphase dynamic computed tomography angiography (CTA) protocol is superior to the standard triphasic protocol for revealing the characteristics of AD. Purpose To examine two multiphase dynamic protocols, Dynamic four-dimensional (4D) CTA using the shuttle mode and Flash 4D CTA using the high-pitch mode for the assessment of AD and to compare them with the standard triphasic protocol. Material and Methods A total of 54 consecutive patients were randomly and equally assigned to three groups and scanned with a second-generation DSCT scanner...
January 1, 2017: Acta Radiologica
https://www.readbyqxmd.com/read/28430590/treatment-of-esophageal-cancer-with-radiation-therapy-a-pan-chinese-survey-of-radiation-oncologists
#2
Yun Zhang, Jing Liu, Wencheng Zhang, Weiye Deng, Jinbo Yue
Lots of controversies were found about the treatment in relation to radiation therapy (RT) for esophageal squamous cell carcinoma (ESCC). We designed a questionnaire of these controversies to do a pan-Chinese survey of radiation oncologists (ROs). For operable ESCC, 53% ROs chose surgery plus postoperative chemoradiotherapy (CRT), while 40% chose preoperative CRT plus surgery. For target volume of postoperative RT, most ROs (92%) would delineate tumor bed plus involved lymph nodes region before surgery. For definitive RT, most ROs (81%) would give patients higher RT dose to 60-65Gy...
April 5, 2017: Oncotarget
https://www.readbyqxmd.com/read/28410685/evaluation-of-mesh-and-binary-based-contour-propagation-methods-in-4d-thoracic-radiotherapy-treatments-using-patient-4d-ct-images
#3
Yuanyuan Ma, Xinguo Liu, Zhongying Dai, Pengbo He, Yuanlin Yan, Guosheng Shen, Ping Yuan, Qiang Li
Based on four dimensional (4D) computed tomography (CT) images, mesh- and binary-based contour propagation algorithms for 4D thoracic radiotherapy treatments were evaluated. Gross tumor volumes (GTVs), lungs, hearts and spinal cords on the CT images at the end-exhale and end-inhale phases for six patients were delineated by the physician. All volumes of interest (VOIs) were automatically propagated from the end-exhale phase to the end-inhale phase using two propagation methods. The propagated VOIs were quantitatively compared with the VOIs contoured at the end-inhale phase by the physician using Dice Similarity Coefficient (DSC), Mean Slicewise Hausdorff Distance (MSHD), Center Of Mass (COM) displacement and volume difference...
April 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28408632/4d-dsa-for-dynamic-visualization-of-cerebral-vasculature-a-single-center-experience-in-26-cases
#4
S Lang, P Gölitz, T Struffert, J Rösch, K Rössler, M Kowarschik, C Strother, A Doerfler
BACKGROUND AND PURPOSE: 4D DSA allows acquisition of time-resolved 3D reconstructions of cerebral vessels by using C-arm conebeam CT systems. The aim of our study was to evaluate this new method by qualitative and quantitative means. MATERIALS AND METHODS: 2D and 4D DSA datasets were acquired in patients presenting with AVMs, dural arteriovenous fistulas, and cerebral aneurysms. 4D DSA was compared with 2D DSA in a consensus reading of qualitative and quantitative parameters of AVMs (eg, location, feeder, associated aneurysms, nidus size, drainage, Martin-Spetzler Score), dural arteriovenous fistulas (eg, fistulous point, main feeder, diameter of the main feeder, drainage), and cerebral aneurysms (location, neck configuration, aneurysmal size)...
April 13, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28390002/a-tool-for-validating-mri-guided-strategies-a-digital-breathing-ct-mri-phantom-of-the-abdominal-site
#5
Chiara Paganelli, Paul Summers, Chiara Gianoli, Massimo Bellomi, Guido Baroni, Marco Riboldi
Dynamic magnetic resonance imaging (MRI) is emerging as the elected image modality for organ motion quantification and management in image-guided radiotherapy. However, the lack of validation tools is an open issue for image guidance in the abdominal and thoracic organs affected by organ motion due to respiration. We therefore present an abdominal four-dimensional (4D) CT/MRI digital phantom, including the estimation of MR tissue parameters, simulation of dedicated abdominal MR sequences, modeling of radiofrequency coil response and noise, followed by k-space sampling and image reconstruction...
April 8, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28384187/target-localization-of-3d-versus-4d-cone-beam-computed-tomography-in-lipiodol-guided-stereotactic-radiotherapy-of-hepatocellular-carcinomas
#6
Mark Chan, Chi Leung Chiang, Venus Lee, Steven Cheung, Ronnie Leung, Matthew Wong, Frankle Lee, Oliver Blanck
BACKGROUND: Aim of this study was to comparatively evaluate the accuracy of respiration-correlated (4D) and uncorrelated (3D) cone beam computed tomography (CBCT) in localizing lipiodolized hepatocellular carcinomas during stereotactic body radiotherapy (SBRT). METHODS: 4D-CBCT scans of eighteen HCCs were acquired during free-breathing SBRT following trans-arterial chemo-embolization (TACE) with lipiodol. Approximately 1320 x-ray projections per 4D-CBCT were collected and phase-sorted into ten bins...
2017: PloS One
https://www.readbyqxmd.com/read/28372795/a-four-dimensional-computed-tomography-comparison-of-healthy-and-asthmatic-human-lungs
#7
Nariman Jahani, Sanghun Choi, Jiwoong Choi, Babak Haghighi, Eric A Hoffman, Alejandro P Comellas, Joel N Kline, Ching-Long Lin
The purpose of this study was to explore new insights in non-linearity, hysteresis and ventilation heterogeneity of asthmatic human lungs using four-dimensional computed tomography (4D-CT) image data acquired during tidal breathing. Volumetric image data were acquired for 5 non-severe and one severe asthmatic volunteers. Besides 4D-CT image data, function residual capacity and total lung capacity image data during breath-hold were acquired for comparison with dynamic scans. Quantitative results were compared with the previously reported analysis of five healthy human lungs...
March 18, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/28371774/a-novel-method-of-cone-beam-ct-projection-binning-based-on-image-registration
#8
Seonyeong Park, Siyong Kim, Byongyong Yi, Geoffrey Hugo, H Michael Gach, Yuichi Motai
Accurate sorting of beam projections is important in four-dimensional Cone Beam Computed Tomography (4D CBCT) to improve the quality of the reconstructed 4D CBCT image by removing motion-induced artifacts. We propose Image Registration-based Projection Binning (IRPB), a novel marker-less binning method for 4D CBCT projections, which combines Intensity-based Feature Point Detection (IFPD) and Trajectory Tracking using Random sample consensus (TTR). IRPB extracts breathing motion and phases by analyzing tissue feature point trajectories...
March 31, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28369900/examination-of-a-deformable-motion-model-for-respiratory-movements-and-4d-dose-calculations-using-different-driving-surrogates
#9
Jens Wölfelschneider, Matteo Seregni, Aurora Fassi, Marc Ziegler, Guido Baroni, Rainer Fietkau, Marco Riboldi, Christoph Bert
PURPOSE: The aim of this study is to evaluate a surrogate-driven motion model based on four-dimensional computed tomography that is able to predict CT volumes corresponding to arbitrary respiratory phases. Further, the comparison of three different driving surrogates is examined and the feasibility of using the model for 4D dose re-calculation will be discussed. METHODS: The study is based on repeated 4DCTs of twenty patients treated for bronchial carcinoma and metastasis...
March 30, 2017: Medical Physics
https://www.readbyqxmd.com/read/28366753/the-position-and-role-of-4d-cta-in-the-diagnosis-and-treatment-of-spinal-arteriovenous-fistulas
#10
Satoshi Yamaguchi, Kohei Takemoto, Masaaki Takeda, Yosuke Kajihara, Takafumi Mitsuhara, Manish Kolakshyapati, Kazutoshi Mukada, Kaoru Kurisu
BACKGROUND: Localization of the arteriovenous fistula (AVF) is a crucial step in the diagnosis and treatment of spinal vascular malformations (VMs). Non-invasive angiographic techniques such as dynamic magnetic resonance angiography (MRA) and 3-dimensional computed tomography angiography (3D-CTA) have been used as standard modalities to localize AVF. With the increasing prevalence of high-spec CT scanner, 4D-CTA is being increasingly utilized in the evaluation of cerebrovascular disorders...
March 30, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28366054/advanced-imaging-in-acute-ischemic-stroke
#11
REVIEW
Craig Kilburg, J Scott McNally, Adam de Havenon, Philipp Taussky, M Yashar S Kalani, Min S Park
The evaluation and management of acute ischemic stroke has primarily relied on the use of conventional CT and MRI techniques as well as lumen imaging sequences such as CT angiography (CTA) and MR angiography (MRA). Several newer or less-established imaging modalities, including vessel wall MRI, transcranial Doppler ultrasonography, and 4D CTA and MRA, are being developed to complement conventional CT and MRI techniques. Vessel wall MRI provides high-resolution analysis of both extracranial and intracranial vasculature to help identify previously occult lesions or characteristics of lesions that may portend a worse natural history...
April 2017: Neurosurgical Focus
https://www.readbyqxmd.com/read/28363893/osseous-impingement-occurs-early-in-flexion-in-cam-type-femoroacetabular-impingement-a-4d-ct-model
#12
S Fernquest, C Arnold, A Palmer, J Broomfield, J Denton, A Taylor, S Glyn-Jones
AIMS: The aim of this study was to examine the real time in vivo kinematics of the hip in patients with cam-type femoroacetabular impingement (FAI). PATIENTS AND METHODS: A total of 50 patients (83 hips) underwent 4D dynamic CT scanning of the hip, producing real time osseous models of the pelvis and femur being moved through flexion, adduction, and internal rotation. The location and size of the cam deformity and its relationship to the angle of flexion of the hip and pelvic tilt, and the position of impingement were recorded...
April 2017: Bone & Joint Journal
https://www.readbyqxmd.com/read/28359341/monitoring-of-breathing-motion-in-image-guided-pbs-proton-therapy-comparative-analysis-of-optical-and-electromagnetic-technologies
#13
Giovanni Fattori, Sairos Safai, Pablo Fernández Carmona, Marta Peroni, Rosalind Perrin, Damien Charles Weber, Antony John Lomax
BACKGROUND: Motion monitoring is essential when treating non-static tumours with pencil beam scanned protons. 4D medical imaging typically relies on the detected body surface displacement, considered as a surrogate of the patient's anatomical changes, a concept similarly applied by most motion mitigation techniques. In this study, we investigate benefits and pitfalls of optical and electromagnetic tracking, key technologies for non-invasive surface motion monitoring, in the specific environment of image-guided, gantry-based proton therapy...
March 31, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/28358668/evolution-of-18-f-fluorodeoxyglucose-and-18-f-fluoroazomycin-arabinoside-pet-uptake-distributions-in-lung-tumours-during-radiation-therapy
#14
Dario Di Perri, John A Lee, Anne Bol, François-Xavier Hanin, Guillaume Janssens, Daniel Labar, Annie Robert, Edmond Sterpin, Xavier Geets
BACKGROUND: Dose painting (DP) aims to improve radiation therapy (RT) outcome by targeting radioresistant tumour regions identified through functional imaging, e.g., positron emission tomography (PET). Importantly, the expected benefit of DP relies on the ability of PET imaging to identify tumour areas which could be consistently targeted throughout the treatment. In this study, we analysed the spatial stability of two potential DP targets in lung cancer patients undergoing RT: the tumour burden surrogate [(18)F]fluorodeoxyglucose (FDG) and the hypoxia surrogate [(18)F]fluoroazomycin arabinoside (FAZA)...
April 2017: Acta Oncologica
https://www.readbyqxmd.com/read/28341317/target-volume-and-artifact-evaluation-of-a-new-data-driven-4d-ct
#15
Rachael Martin, Tinsu Pan
PURPOSE: Four-dimensional computed tomography (4D CT) is often used to define the internal gross target volume (IGTV) for radiation therapy of lung cancer. Traditionally, this technique requires the use of an external motion surrogate; however, a new image, data-driven 4D CT, has become available. This study aims to describe this data-driven 4D CT and compare target contours created with it to those created using standard 4D CT. METHODS AND MATERIALS: Cine CT data of 35 patients undergoing stereotactic body radiation therapy were collected and sorted into phases using standard and data-driven 4D CT...
February 2, 2017: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28335780/considerable-interobserver-variation-in-delineation-of-pancreatic-cancer-on-3dct-and-4dct-a-multi-institutional-study
#16
Eva Versteijne, Oliver J Gurney-Champion, Astrid van der Horst, Eelco Lens, M Willemijn Kolff, Jeroen Buijsen, Gati Ebrahimi, Karen J Neelis, Coen R N Rasch, Jaap Stoker, Marcel van Herk, Arjan Bel, Geertjan van Tienhoven
BACKGROUND: The delineation of pancreatic tumors on CT is challenging. In this study, we quantified the interobserver variation for pancreatic tumor delineation on 3DCT as well as on 4DCT. METHODS: Eight observers (radiation oncologists) from six institutions delineated pancreatic tumors of four patients with (borderline) resectable pancreatic cancer. The study consisted of two stages. In the 3DCT-stage, the gross tumor volume (GTV) was delineated on a contrast-enhanced scan...
March 23, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/28300367/4d-vmat-planning-and-verification-technique-for-dynamic-tracking-using-a-direct-aperture-deformation-dad-method
#17
Yongqian Zhang, Yong Yang, Weihua Fu, Xiang Li, Tianfang Li, Dwight E Heron, M Saiful Huq
We developed a four-dimensional volumetric modulated arc therapy (4D VMAT) planning technique for moving targets using a direct aperture deformation (DAD) method and investigated its feasibility for clinical use. A 3D VMAT plan was generated on a reference phase of a 4D CT dataset. The plan was composed of a set of control points including the beam angle, MLC apertures and weights. To generate the 4D VMAT plan, these control points were assigned to the closest respiratory phases using the temporal information of the gantry angle and respiratory curve...
March 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297341/assessment-of-monte-carlo-algorithm-for-compliance-with-rtog-0915-dosimetric-criteria-in-peripheral-lung-cancer-patients-treated-with-stereotactic-body-radiotherapy
#18
Damodar Pokhrel, Sumit Sood, Rajeev Badkul, Hongyu Jiang, Christopher McClinton, Christopher Lominska, Parvesh Kumar, Fen Wang
The purpose of the study was to evaluate Monte Carlo-generated dose distributions with the X-ray Voxel Monte Carlo (XVMC) algorithm in the treatment of peripheral lung cancer patients using stereotactic body radiotherapy (SBRT) with non-protocol dose-volume normalization and to assess plan outcomes utilizing RTOG 0915 dosimetric compliance criteria. The Radiation Therapy Oncology Group (RTOG) protocols for non-small cell lung cancer (NSCLC) currently require radiation dose to be calculated using tissue density heterogeneity corrections...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297332/impact-of-incorporating-visual-biofeedback-in-4d-mri
#19
David T To, Joshua P Kim, Ryan G Price, Indrin J Chetty, Carri K Glide-Hurst
Precise radiation therapy (RT) for abdominal lesions is complicated by respiratory motion and suboptimal soft tissue contrast in 4D CT. 4D MRI offers improved contrast although long scan times and irregular breathing patterns can be limiting. To address this, visual biofeedback (VBF) was introduced into 4D MRI. Ten volunteers were consented to an IRB-approved protocol. Prospective respiratory-triggered, T2-weighted, coronal 4D MRIs were acquired on an open 1.0T MR-SIM. VBF was integrated using an MR-compatible interactive breath-hold control system...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297304/evaluation-of-kidney-motion-and-target-localization-in-abdominal-sbrt-patients
#20
Marcus Sonier, William Chu, Nafisha Lalani, Darby Erler, Patrick Cheung, Renee Korol
The purpose of this study was to evaluate bilateral kidney and target translational/rotational intrafraction motion during stereotactic body radiation therapy treatment delivery of primary renal cell carcinoma and oligometastatic adrenal lesions for patients immobilized in the Elekta BodyFIX system. Bilateral kidney motion was assessed at midplane for 30 patients immobilized in a full-body dual-vacuum-cushion system with two patients immobilized via abdominal compression. Intrafraction motion was assessed for 15 patients using kilovoltage cone-beam computed tomography (kV-CBCT) datasets (n=151) correlated to the planning CT...
November 2016: Journal of Applied Clinical Medical Physics
keyword
keyword
92855
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"