keyword
MENU ▼
Read by QxMD icon Read
search

Four dimensional ct

keyword
https://www.readbyqxmd.com/read/28822316/improved-middle-ear-soft-tissue-visualization-using-synchrotron-radiation-phase-contrast-imaging
#1
Mai Elfarnawany, Seyed Alireza Rohani, Soroush Ghomashchi, Daniel G Allen, Ning Zhu, Sumit K Agrawal, Hanif M Ladak
High resolution images are used as a basis for finite-element modeling of the middle-ear structures to study their biomechanical function. Commonly used imaging techniques such as micro-computed tomography (CT) and optical microscopy require extensive sample preparation, processing or staining using contrast agents to achieve sufficient soft-tissue contrast. We compare imaging of middle-ear structures in unstained, non-decalcified human temporal bones using conventional absorption-contrast micro-CT and using synchrotron radiation phase-contrast imaging (SR-PCI)...
August 5, 2017: Hearing Research
https://www.readbyqxmd.com/read/28817381/advanced-radiation-dosimetry-phantom-ardos-a-versatile-breathing-phantom-for-4d-radiation-therapy-and-medical-imaging
#2
Natalia Kostiukhina, Dietmar Georg, Sofia Rollet, Peter Kuess, Andrej Sipaj, Piotr Andrzejewski, Hugo Furtado, Ivo Rausch, Wolfgang Lechner, Elisabeth Steiner, Hunor Kertesz, Barbara Knaeusl
A novel breathing phantom was designed for being used in conventional and ion-beam radiotherapy as well as for medical imaging. Accurate dose delivery and patient safety are aimed to be verified for four-dimensional (4D) treatment techniques compensating for breathing-induced tumor motion. The phantom includes anthropomorphic components representing an average human thorax. It consists of real tissue equivalent materials to fulfill the requirements for dosimetric experiments and imaging purposes. The different parts of the torso (lungs, chest wall, and ribs) and the tumor can move independently...
August 17, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28816159/consensus-guidelines-for-implementing-pencil-beam-scanning-proton-therapy-for-thoracic-malignancies-on-behalf-of-the-ptcog-thoracic-and-lymphoma-subcommittee
#3
REVIEW
Joe Y Chang, Xiaodong Zhang, Antje Knopf, Heng Li, Shinichiro Mori, Lei Dong, Hsiao-Ming Lu, Wei Liu, Shahed N Badiyan, Stephen Both, Arturs Meijers, Liyong Lin, Stella Flampouri, Zuofeng Li, Kikuo Umegaki, Charles B Simone, Xiaorong R Zhu
Pencil-beam scanning (PBS) proton therapy (PT), particularly intensity modulated PT, represents the latest advanced PT technology for treating cancers, including thoracic malignancies. On the basis of virtual clinical studies, PBS-PT appears to have great potential in its ability to tightly tailor the dose to the target while sparing critical structures, thereby reducing treatment-related toxicities, particularly for tumors in areas with complicated anatomy. However, implementing PBS-PT for moving targets has several additional technical challenges compared with intensity modulated photon radiation therapy or passive scattering PT...
September 1, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28816147/evaluating-which-dose-function-metrics-are-most-critical-for-functional-guided-radiation-therapy
#4
Austin M Faught, Tokihiro Yamamoto, Richard Castillo, Edward Castillo, Jingjing Zhang, Moyed Miften, Yevgeniy Vinogradskiy
PURPOSE: Four-dimensional (4D) computed tomography (CT) ventilation imaging is increasingly being used to calculate lung ventilation and implement functional-guided radiation therapy in clinical trials. There has been little exhaustive work evaluating which dose-function metrics should be used for treatment planning and plan evaluation. The purpose of our study was to evaluate which dose-function metrics best predict for radiation pneumonitis (RP). METHODS AND MATERIALS: Seventy lung cancer patients who underwent 4D CT imaging and pneumonitis grading were assessed...
September 1, 2017: International Journal of Radiation Oncology, Biology, Physics
https://www.readbyqxmd.com/read/28815587/beveled-posteromedial-corner-of-the-radial-head-a-three-dimensional-micro-computed-tomography-modeling-study
#5
Arnold Adikrishna, Young-Ho Shin, Rizki F Zulkarnain, Hanpyo Hong, Yucheng Sun, In-Ho Jeon
The posteromedial quadrant of the radial head is known to be different from the other quadrants. However, the explanation of this unique anatomical feature remains elusive. Hence, this study was designed to address this unique anatomical variance using three-dimensional μCT (micro-computed tomography) analysis. Nine fresh cadaveric radial heads were scanned using μCT. Three-dimensional subchondral bone and cartilage models were rendered. Both models were separated into the four quadrants at both the periphery (rim) and the articulating dish (fovea): anteromedial (AM), posteromedial (PM), posterolateral (PL), and anterolateral (AL)...
August 15, 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/28810162/standardized-anthropological-measurement-of-postcranial-bones-using-three-dimensional-models-in-cad-software
#6
Mikaela S Reynolds, Donna M MacGregor, Mark D Barry, Nicolene Lottering, Beat Schmutz, Lance J Wilson, Matthew Meredith, Laura S Gregory
This study introduces a standardized protocol for conducting linear measurements of postcranial skeletal elements using three-dimensional (3D) models constructed from post-mortem computed tomography (PMCT) scans. Using femoral DICOM datasets, reference planes were generated and plane-to-plane measurements were conducted on 3D surface rendered models. Bicondylar length, epicondylar breadth, anterior-posterior (AP) diameter, medial-lateral (ML) diameter and cortical area at the midshaft were measured by four observers to test the measurement error variance and observer agreement of the protocol (n=6)...
July 26, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28800569/surgery-for-refractory-coccygodynia-operative-versus-nonoperative-treatment
#7
John P Kleimeyer, Kirkham B Wood, Greger Lønne, Tyler Herzog, Kevin Ju, Lisa Beyer, Christine Park
STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: To evaluate the long-term outcomes for patients with refractory coccygodynia treated with coccygectomy compared to a nonsurgical regimen of sitting aids, physical therapy, medications, and injections. SUMMARY OF BACKGROUND DATA: The surgical treatment of coccygodynia remains controversial. To date, there has only been one small comparative study of surgical versus nonsurgical treatment...
August 15, 2017: Spine
https://www.readbyqxmd.com/read/28794161/how-pigeons-couple-three-dimensional-elbow-and-wrist-motion-to-morph-their-wings
#8
Amanda K Stowers, Laura Y Matloff, David Lentink
Birds change the shape and area of their wings to an exceptional degree, surpassing insects, bats and aircraft in their ability to morph their wings for a variety of tasks. This morphing is governed by a musculoskeletal system, which couples elbow and wrist motion. Since the discovery of this effect in 1839, the planar 'drawing parallels' mechanism has been used to explain the coupling. Remarkably, this mechanism has never been corroborated from quantitative motion data. Therefore, we measured how the wing skeleton of a pigeon (Columba livia) moves during morphing...
August 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28790813/asynchrony-in-respiratory-movements-between-the-pulmonary-lobes-in-patients-with-copd-continuous-measurement-of-lung-density-by-4-dimensional-dynamic-ventilation-ct
#9
Tsuneo Yamashiro, Hiroshi Moriya, Shin Matsuoka, Yukihiro Nagatani, Maho Tsubakimoto, Nanae Tsuchiya, Sadayuki Murayama
PURPOSE: Four-dimensional dynamic-ventilation CT imaging demonstrates continuous movement of the lung. The aim of this study was to assess the correlation between interlobar synchrony in lung density and spirometric values in COPD patients and smokers, by measuring the continuous changes in lung density during respiration on the dynamic-ventilation CT. MATERIALS AND METHODS: Thirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during free breathing...
2017: International Journal of Chronic Obstructive Pulmonary Disease
https://www.readbyqxmd.com/read/28765804/integrated-fixation-cage-loosening-under-fatigue-loading
#10
Srinidhi Nagaraja, Vivek Palepu
BACKGROUND: Screw loosening is a well-known adverse event in traditional spinal fusion instrumentation. This phenomenon may hinder segmental stability of the spine leading to bony non-union. In recent years numerous lumbar integrated fixation cages (IFC) have been introduced that offer a low profile alternative to a standard cage with an anterior plate (AP+C). The fixation approach for IFCs is different than a traditional anterior approach; therefore, it is unclear whether IFCs may loosen from the surrounding bone over time...
2017: International Journal of Spine Surgery
https://www.readbyqxmd.com/read/28765192/four-dimensional-ct-guided-transcatheter-removal-of-a-fractured-migrated-catheter-of-a-totally-implantable-venous-access-port
#11
Kazushi Fujimoto, Hajime Kasai, Toshihiko Sugiura, Koichiro Tatsumi
Patients undergoing chemotherapy usually undergo placement of a totally implantable venous access port (TIVAP), but TIVAP catheter fracture is rare. We encountered a case where flushing the TIVAP catheter became impossible because of resistance. A 61-year-old-woman underwent TIVAP placement. Although a chest X-ray revealed the fractured catheter had migrated into the right hilar area, the timing of the fracture was unclear. Four-dimensional computed tomography (4D-CT) showed that the tip of the fractured catheter was located at the anterior segmental artery of the right upper lobe and was immobile, with the remaining portion flapping with the blood flow...
August 1, 2017: BMJ Case Reports
https://www.readbyqxmd.com/read/28762166/accuracy-and-specific-value-of-cardiovascular-3d-models-in-pediatric-ct-angiography
#12
Matthias Hammon, Oliver Rompel, Hannes Seuss, Sven Dittrich, Michael Uder, Andrè Rüffer, Robert Cesnjevar, Nicole Ehret, Martin Glöckler
Computed tomography (CT)-angiography is routinely performed prior to catheter-based and surgical treatment in congenital heart disease. To date, little is known about the accuracy and advantage of different 3D-reconstructions in CT-data. Exact anatomical information is crucial. We analyzed 35 consecutive CT-angiographies of infants with congenital heart disease. All datasets are reconstructed three-dimensionally using volume rendering technique (VRT) and threshold-based segmentation (stereolithographic model, STL)...
July 31, 2017: Pediatric Cardiology
https://www.readbyqxmd.com/read/28753247/take-away-body-parts-an-investigation-into-the-use-of-3d-printed-anatomical-models-in-undergraduate-anatomy-education
#13
Claire F Smith, Nicholas Tollemache, Derek Covill, Malcolm Johnston
Understanding the three-dimensional (3D) nature of the human form is imperative for effective medical practice and the emergence of 3D printing creates numerous opportunities to enhance aspects of medical and healthcare training. A recently deceased, un-embalmed donor was scanned through high-resolution computed tomography. The scan data underwent segmentation and post-processing and a range of 3D-printed anatomical models were produced. A four-stage mixed-methods study was conducted to evaluate the educational value of the models in a medical program...
July 28, 2017: Anatomical Sciences Education
https://www.readbyqxmd.com/read/28748855/clinical-characteristics-and-endoscopic-endonasal-removal-of-foreign-bodies-within-sinuses-orbit-and-skull-base
#14
Yi-Hui Wen, Wei-Jian Hou, Wen-Bin Lei, Feng-Hong Chen, Xiao-Lin Zhu, Zhang-Feng Wang, Ren-Qiang Ma, Wei-Ping Wen
BACKGROUND: Foreign bodies within the sinuses, orbit, and skull base (FBSOS) are rare; hence, diagnosis and management guidelines are lacking. Endoscopic sinus surgery (ESS) removal is preferred because of the less invasiveness and minimal morbidity. This study was designed to summarize clinical experience with ESS management of FBSOS. METHODS: We retrospectively reviewed clinical manifestations, imaging findings, treatment, and outcomes in consecutive patients with ESS removal of FBSOS between 2004 and 2015 at a tertiary academic medical center...
August 5, 2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28744552/macular-vascular-fractal-dimension-in-the-deep-capillary-layer-as-an-early-indicator-of-microvascular-loss-for-retinopathy-in-type-2-diabetic-patients
#15
Qi Chen, Qingkai Ma, Chaoming Wu, Fan Tan, Feng Chen, Qiuyan Wu, Rong Zhou, Xiran Zhuang, Fan Lu, Jia Qu, Meixiao Shen
Purpose: To determine the ability of fractal dimension to detect early changes in the retinal microvascular network imaged by optical coherence tomography angiography (OCT-A) in type 2 diabetic patients. Methods: Sixty-seven patients with type 2 diabetic mellitus (DM) (48 with no diabetic retinopathy [DR], 19 with minimal DR) and 40 control subjects. Macular OCT-A images of the superficial and deep retinal capillary layers in a 2.5-mm diameter concentric annular zone (excluding the foveal avascular zone) were subdivided into six annular rings and four quadrants...
July 1, 2017: Investigative Ophthalmology & Visual Science
https://www.readbyqxmd.com/read/28742788/computer-assisted-corrective-osteotomy-of-malunited-pediatric-radial-neck-fractures-three-dimensional-postoperative-accuracy-and-clinical-outcome
#16
Lizzy Weigelt, Philipp Fürnstahl, Andreas Schweizer
Neglected or incorrect treatment of pediatric radial neck fractures may lead to symptomatic malunions. Computer-assisted corrective osteotomies with patient-specific guides have been proposed as a promising technique for the reconstruction of malunited long bone deformities. The aim of this study was to evaluate the accuracy and clinical outcome of this technique in children with malunited fractures of the radial neck. Four children (two male, two female; mean age 12 (10-16) years) underwent computer-assisted closing wedge osteotomy of the radial neck...
July 24, 2017: Journal of Orthopaedic Trauma
https://www.readbyqxmd.com/read/28740918/impact-of-moving-target-on-measurement-accuracy-in-3d-and-4d-pet-imaging-a-phantom-study
#17
Yunfeng Cui, James Bowsher, Jing Cai, Fang-Fang Yin
PURPOSE: The purpose of this study was to evaluate the impact of tumor motion on maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) measurements in both 3-dimensional and respiratory-correlated, 4-dimensional positron emission tomography (PET) imaging. We also evaluated the effect of implementing different attenuation correction methods in 4-dimensional PET image reconstruction on SUVmax and MTV. METHODS AND MATERIALS: An anthropomorphic thorax phantom with a spherical ball as a surrogate for a tumor was used...
January 2017: Advances in Radiation Oncology
https://www.readbyqxmd.com/read/28738005/accuracy-and-repeatability-of-long-bone-replicas-of-small-animals-fabricated-by-use-of-low-end-and-high-end-commercial-three-dimensional-printers
#18
Jamie A Cone, Thomas M Martin, Denis J Marcellin-Little, Ola L A Harrysson, Emily H Griffith
OBJECTIVE To assess the repeatability and accuracy of polymer replicas of small, medium, and large long bones of small animals fabricated by use of 2 low-end and 2 high-end 3-D printers. SAMPLE Polymer replicas of a cat femur, dog radius, and dog tibia were fabricated in triplicate by use of each of four 3-D printing methods. PROCEDURES 3-D renderings of the 3 bones reconstructed from CT images were prepared, and length, width of the proximal aspect, and width of the distal aspect of each CT image were measured in triplicate...
August 2017: American Journal of Veterinary Research
https://www.readbyqxmd.com/read/28726056/interobserver-variability-of-patient-positioning-using-four-different-ct-datasets-for-image-registration-in-lung-stereotactic-body-radiotherapy
#19
Markus Oechsner, Barbara Chizzali, Michal Devecka, Stefan Münch, Stephanie Elisabeth Combs, Jan Jakob Wilkens, Marciana Nona Duma
PURPOSE: To assess the impact of different reference CT datasets on manual image registration with free-breathing three-dimensional (3D) cone beam CTs (FB-CBCT) for patient positioning by several observers. METHODS: For 48 patients with lung lesions, manual image registration with FB-CBCTs was performed by four observers. A slow planning CT (PCT), average intensity projection (AIP), maximum intensity projection (MIP), and midventilation CT (MidV) were used as reference images...
July 19, 2017: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
https://www.readbyqxmd.com/read/28724752/the-fluid-mechanics-of-transcatheter-heart-valve-leaflet-thrombosis-in-the-neo-sinus
#20
Prem A Midha, Vrishank Raghav, Rahul Sharma, Jose F Condado, Ikechukwu U Okafor, Tanya Rami, Gautam Kumar, Vinod H Thourani, Hasan Jilaihawi, Vasilis Babaliaros, Raj R Makkar, Ajit P Yoganathan
Background -Transcatheter heart valve (THV) thrombosis has been increasingly reported. In these studies, thrombus quantification has been based on 2D assessment of a 3D phenomenon. Methods -Post-procedural four-dimensional, volume-rendered CT (4DCT) data of CoreValve, Evolut R, and SAPIEN 3 transcatheter aortic valve replacement (TAVR) patients enrolled in the RESOLVE trial were included in this analysis. Patients on anticoagulation were excluded. SAPIEN 3 and CoreValve/Evolut R patients with and without hypo-attenuated leaflet thickening (HALT) were included in order to study differences between groups...
July 19, 2017: Circulation
keyword
keyword
42072
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"