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https://www.readbyqxmd.com/read/28441646/spontaneous-regression-of-possible-transcatheter-aortic-valve-thrombosis-without-additional-anticoagulant-two-year-follow-up
#1
Ryo Yanagisawa, Kentaro Hayashida, Masahiro Jinzaki, Keiichi Fukuda
An 84-year-old man with symptomatic severe aortic stenosis received transcatheter aortic valve implantation (TAVI). Dual-antiplatelet therapy was continued for 6 months post TAVI, and aspirin alone was used thereafter. Four-dimensional multidetector computed tomography revealed a new hypoattenuated leaflet thickening (HALT) with reduced leaflet motion at 1 year, considered to indicate leaflet thrombosis. At the 2-year follow-up, leaflet mobility had improved, with spontaneous regression of HALT. This is the first report of confirmed spontaneous regression of possible transcatheter heart valve thrombosis and recovery of leaflet mobility without the need for additional anticoagulant...
May 2017: Journal of Invasive Cardiology
https://www.readbyqxmd.com/read/28440669/can-multiphase-dynamic-ct-angiography-provide-a-better-assessment-of-aortic-dissection-compared-with-the-standard-triphasic-protocol
#2
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/28437565/relaxed-ordered-subset-preconditioned-alternating-projection-algorithm-for-pet-reconstruction-with-automated-penalty-weight-selection
#3
C Ross Schmidtlein, Yizun Lin, Si Li, Andrzej Krol, Bradley J Beattie, John L Humm, Yuesheng Xu
PURPOSE: Performance of the preconditioned alternating projection algorithm (PAPA) using relaxed ordered subsets (ROS) with a non-smooth penalty function was investigated in positron emission tomography (PET). A higher order total variation (HOTV) regularizer was applied and a method for unsupervised selection of penalty weights based on the measured data is introduced. METHODS: A ROS version of PAPA with HOTV penalty (ROS-HOTV-PAPA) for PET image reconstruction was developed and implemented...
April 24, 2017: Medical Physics
https://www.readbyqxmd.com/read/28437349/a-new-navigational-tool-for-pedicle-screw-placement-in-patients-with-severe-scoliosis-a-pilot-study-to-prove-feasibility-accuracy-and-identify-operative-challenges
#4
Michael Putzier, Patrick Strube, Riccardo Cecchinato, Claudio Lamartina, Eike K Hoff
STUDY DESIGN: Pilot study. OBJECTIVE: To develop and validate the feasibility and accuracy of a newly designed navigational spinal instrument guiding tool for patient-matched thoracic and lumbar pedicle screw placement in patients with severe scoliosis, and to identify intraoperative challenges that may be relevant. SUMMARY OF BACKGROUND DATA: Pedicle screw placement is challenging in severely rotated scoliotic spine with small diameters and asymmetrical shape of the pedicles and vertebrae...
May 2017: Clinical Spine Surgery
https://www.readbyqxmd.com/read/28436852/frequency-selective-computed-tomography-applications-during-periodic-thoracic-motion
#5
Jacob Herrmann, Eric A Hoffman, David W Kaczka
We seek to use computed tomography (CT) to characterize regional lung parenchymal deformation during highfrequency and multi-frequency oscillatory ventilation. Periodic motion of thoracic structures results in artifacts of CT images obtained by standard reconstruction algorithms, especially for frequencies exceeding that of the X-ray source rotation. In this study, we propose an acquisition and reconstruction technique for high resolution imaging of the thorax during periodic motion. Our technique relies on phase-binning projections according to the frequency of subject motion relative to the scanner rotation, prior to volumetric reconstruction...
April 18, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28430590/treatment-of-esophageal-cancer-with-radiation-therapy-a-pan-chinese-survey-of-radiation-oncologists
#6
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/28429371/design-of-a-short-non-uniform-acquisition-protocol-for-quantitative-analysis-in-dynamic-cardiac-spect-imaging-a-retrospective-123-i-mibg-animal-study
#7
Yunlong Zan, Yong Long, Kewei Chen, Biao Li, Qiu Huang, Grant T Gullberg
PURPOSE: Our previous works have found that quantitative analysis of (123) I-MIBG kinetics in the heart with dynamic single-photon emission computed tomography (SPECT) offers the potential to quantify the innervation integrity at an early stage of left ventricular hypertrophy. However, conventional protocols involving a long acquisition time for dynamic imaging reduce the animal survival rate and thus make longitudinal analysis difficult. The goal of this work was to develop a procedure to reduce the total acquisition time by selecting non-uniform acquisition times for projection views while maintaining the accuracy and precision of estimated physiologic parameters...
April 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28428149/local-control-and-toxicity-of-adaptive-radiotherapy-using-weekly-ct-imaging-results-from-the-lartia-trial-in-stage-iii-nsclc
#8
Sara Ramella, Michele Fiore, Sonia Silipigni, Maria Cristina Zappa, Massimo Jaus, Antonio Maria Alberti, Paolo Matteucci, Elisabetta Molfese, Patrizia Cornacchione, Carlo Greco, Lucio Trodella, Edy Ippolito, Rolando Maria D'Angelillo
INTRODUCTION: Anatomical change of tumor during radiotherapy contributes to target missing. However, in case of tumor shrinkage adaptation of volume could results in an increased incidence of recurrences in the area of target reduction. This study aims to investigate the incidence of failure of adaptive approach and in particular the risk of local recurrence in the area excluded after replanning. METHODS: In this prospective study, LA-NSCLC patients treated with concomitant chemoradiation underwent weekly chest-CT simulation during treatment...
April 17, 2017: Journal of Thoracic Oncology
https://www.readbyqxmd.com/read/28417054/three-dimensional-and-topographic-relationships-between-the-orbital-margins-with-reference-to-assessment-of-eyeball-protrusion
#9
Kang-Jae Shin, Shin-Hyo Lee, Ki-Seok Koh, Wu-Chul Song
This study investigated the topographic relationships among the eyeball and four orbital margins with the aim of identifying the correlation between orbital geometry and eyeball protrusion in Koreans. Three-dimensional (3D) volume rendering of the face was performed using serial computed-tomography images of 141 Koreans, and several landmarks on the bony orbit and the cornea were directly marked on the 3D volumes. The anterior-posterior distances from the apex of the cornea to each orbital margin and between the orbital margins were measured in both eyes...
March 2017: Anatomy & Cell Biology
https://www.readbyqxmd.com/read/28410754/finite-element-analysis-of-the-influence-of-anterior-talofibular-ligament-injury-on-hook-test-results
#10
Lin Zhou, Yongxin Lin, Xu Zhai, Bata Wang, Jiaming Lin
AIM: To determine whether the anterior talofibular ligament injury will influence the Hook test result. METHOD: A three-dimensional model of the ankle was established based on CT scan of a healthy volunteer and ligament attachment through references; Four groups (A-D) of operating conditions were set up. In group A, the anterior and posterior ligaments of the inferior tibiofibular joint were cut off and the anterior talofibular ligament was kept intact; in group B, all the anterior and posterior tibiofibular ligaments and the anterior talofibular ligament were cut off; in group C, the medial and lateral ligaments of the ankle joint and the inferior tibiofibular ligament were kept intact; in group D, only the talofibular ligament was cut off and other ligaments were kept intact...
March 31, 2017: Injury
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
#11
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/28396050/value-of-the-cumulative-sum-test-for-the-assessment-of-a-learning-curve-application-to-the-introduction-of-patient-specific-instrumentation-for-total-knee-arthroplasty-in-an-academic-department
#12
Marco De Gori, Benjamin Adamczewski, Jean-Yves Jenny
BACKGROUND: The purpose of the study was to use the cumulative summation (CUSUM) test to assess the learning curve during the introduction of a new surgical technique (patient-specific instrumentation) in total knee arthroplasty (TKA) in an academic department. METHODS: The first 50TKAs operated on at an academic department using patient-specific templates (PSTs) were scheduled to enter the study. All patients had a preoperative computed tomography scan evaluation to plan bone resections...
April 7, 2017: Knee
https://www.readbyqxmd.com/read/28390002/a-tool-for-validating-mri-guided-strategies-a-digital-breathing-ct-mri-phantom-of-the-abdominal-site
#13
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/28379667/laparoscopic-donor-nephrectomy-in-unusual-venous-anatomy-donor-and-recepient-implications
#14
Avinash Bapusaheb Patil, Tarun Dilip Javali, Harohalli K Nagaraj, S M L Prakash Babu, Arvind Nayak
OBJECTIVES: Laparoscopic donor nephrectomy is now a commonly performed procedure in most of renal transplantation centers. However, the suitability of laparoscopy for donors with abnormal venous anatomy is still a subject of debate. MATERIALS AND METHODS: Between August 2007 and August 2014, 243 laparoscopic donor nephrectomies were performed in our institution. All donors were evaluated with preoperative three-dimensional spiral computed tomography (CT) angiography Thirteen (5...
April 6, 2017: International Braz J Urol: Official Journal of the Brazilian Society of Urology
https://www.readbyqxmd.com/read/28377909/measuring-of-abdominal-aortic-aneurysm-with-three-dimensional-computed-tomography-reconstruction-before-endovascular-aortic-aneurysm-repair
#15
Yoona Chung, Jin Hyun Joh, Ho-Chul Park
PURPOSE: Conventional computed tomography (CT) is the gold standard method for case planning for endovascular aortic aneurysm repair (EVAR). However, aortography with a marking catheter is needed for measuring the actual length of an aneurysm. With advances in imaging technology, a 3-dimensional (3D) workstation can obviate the need for the aortography. The objective of this study was to determine whether a 3D workstation could obviate the need for aortography for EVAR. MATERIALS AND METHODS: One vascular surgeon and 1 interventional radiologist retrospectively assessed axial CT scans and reformatted the 3D CT scans by using the iNtuition workstation (TeraRecon Inc...
March 2017: Vascular Specialist International
https://www.readbyqxmd.com/read/28376780/kinematic-characteristics-of-lumbar-spinous-processes-during-axial-rotation-in-patients-with-lumbar-degenerative-disc-disease-lateral-lumbar-interbody-fusion-and-intervention
#16
BaoLiang Zhang, Wenhan Huang, Hong Xia, Xinglong Feng
BACKGROUND: Data about minimally invasive surgery for the treatment of patients with degenerative disc disease (DDD) has been reported. However, no quantitative knowledge about the biomechanical characteristics of the spinous processes in patients with DDD after operation was reported in the literature. METHODS: Fourteen adult patients with DDD at the L3-4 level were recruited and scanned using computed tomography (CT) to construct three-dimensional (3D) anatomical vertebral models of L2-5...
April 4, 2017: BMC Musculoskeletal Disorders
https://www.readbyqxmd.com/read/28372795/a-four-dimensional-computed-tomography-comparison-of-healthy-and-asthmatic-human-lungs
#17
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
#18
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/28371377/validation-of-a-gpu-based-3d-dose-calculator-for-modulated-beams
#19
Saeed Ahmed, Dylan Hunt, Jeff Kapatoes, Robert Hayward, Geoffrey Zhang, Eduardo G Moros, Vladimir Feygelman
A superposition/convolution GPU-accelerated dose computation algorithm (the Calculator) has been recently incorporated into commercial software. The algorithm requires validation prior to clinical use. Three photon energies were examined: conventional 6 MV and 15 MV, and 10 MV flattening filter free (10 MVFFF). For a set of IMRT and VMAT plans based on four of the five AAPM Practice Guideline 5a downloadable datasets, ion chamber (IC) measurements were performed on the water-equivalent phantoms. The average difference between the Calculator and IC was -0...
March 29, 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28369900/examination-of-a-deformable-motion-model-for-respiratory-movements-and-4d-dose-calculations-using-different-driving-surrogates
#20
Jens W├Âlfelschneider, 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
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