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https://www.readbyqxmd.com/read/28079680/middle-ear-sound-transmission-under-normal-damaged-repaired-and-reconstructed-conditions
#1
Wei Dong, Ying Tian, Xin Gao, Timothy T K Jung
HYPOTHESIS: We hypothesize that current clinical treatment strategies for the disarticulated or eroded incus have the effect of combining the incus and stapes of the human middle ear (ME) into one rigid structure, which, while capable of adequately transmitting lower-frequency sounds, fails for higher frequencies. BACKGROUND: ME damage causes conductive hearing loss (CHL) and while great progress has been made in repairing or reconstructing damaged MEs, the outcomes are often far from ideal...
January 10, 2017: Otology & Neurotology
https://www.readbyqxmd.com/read/28079655/microarchitecture-of-schlemm-canal-before-and-after-selective-laser-trabeculoplasty-in-enhanced-depth-imaging-optical-coherence-tomography
#2
Alon Skaat, Michael S Rosman, Jason L Chien, Mark P Ghassibi, Jeffrey M Liebmann, Robert Ritch, Sung Chul Park
PURPOSE: To characterize the in vivo effect of selective laser trabeculoplasty (SLT) on the Schlemm canal (SC) in eyes with primary open-angle glaucoma (POAG). MATERIALS AND METHODS: Eighty-one serial horizontal enhanced depth imaging optical coherence tomograph B-scans (interval between B-scans, ∼35 μm) of the nasal corneoscleral limbus were obtained before and 4 weeks after SLT. Fifty B-scans in the overlapping regions before and after SLT were selected for analysis based on the structures of aqueous and blood vessels as landmarks...
January 10, 2017: Journal of Glaucoma
https://www.readbyqxmd.com/read/28079527/binary-moving-blocker-based-scatter-correction-in-cone-beam-computed-tomography-with-width-truncated-projections-proof-of-concept
#3
Ho Lee, Benjamin Fahimian, Lei Xing
This paper proposes a binary moving-blocker (BMB)-based technique for scatter correction in cone-beam computed tomography (CBCT). In concept, a beam blocker consisting of lead strips, mounted in front of the x-ray tube, moves rapidly in and out of the beam during a single gantry rotation. The projections are acquired in alternating phases of blocked and unblocked cone beams, where the blocked phase results in a stripe pattern in the width direction. To derive the scatter map from the blocked projections, one-dimensional B-Spline interpolation/extrapolation is applied by using the detected information in the shaded regions...
January 12, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28072657/assessment-of-cochlea-endolymphatic-hydrops-using-3-d-flair-and-3-d-real-ir-sequence-in-guinea-pigs-via-3t-mri-after-intratympanic-gadolinium-a-histopathological-comparison
#4
Feng Wang, Huiying Lyu, Menglong Zhao, Yan Sha, Fang Zhang, Yushu Cheng, Wenhu Huang, Wenlin Tang, Youzhou Xie, Ping Lu
OBJECTIVE: We assessed whether the three-dimensional fluid-attenuated inversion-recovery (3-D FLAIR) and three-dimensional inversion-recovery with real reconstruction (3-D real IR) sequences can be used to detect cochlea endolymphatic hydrops (EHs) in guinea pigs using 3 Tesla magnetic resonance imaging (3T MRI). The results of 3-D real IR imaging were compared with histopathological outcomes. MATERIALS AND METHODS: Fourteen healthy men and women albino guinea pigs were used in this study...
January 9, 2017: Otology & Neurotology
https://www.readbyqxmd.com/read/28072394/three-dimensional-cascaded-system-analysis-of-a-50-%C3%A2%C2%B5m-pixel-pitch-wafer-scale-cmos-active-pixel-sensor-x-ray-detector-for-digital-breast-tomosynthesis
#5
Chumin Zhao, Nikita Vassiljev, Anastasios Konstantinidis, Robert Speller, Jerzy Kanicki
High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 ��m pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30��...
January 10, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28068971/a-comparison-of-the-shaping-ability-of-three-nickel-titanium-rotary-instruments-a-micro-computed-tomography-study-via-a-contrast-radiopaque-technique-in-vitro
#6
Zhao Wei, Zhi Cui, Ping Yan, Han Jiang
BACKGROUND: Micro-CT (μCT) studies that combine simulated canals with meglucamine diatrizoate to evaluate the shaping ability of nickel-titanium (NiTi) rotary instruments are lacking in the literature. The purpose of this study was to evaluate the shaping ability of three new different nickel-titanium rotary instruments in simulated root canals using μCT. METHODS: Thirty simulated root canals with a curvature of 60° were randomly allocated into the following 3 groups (n = 10): Group 1, ProTaper Universal (PTU) rotary system; Group 2, Reciproc single-file system; and Group 3, K3XF rotary system...
January 9, 2017: BMC Oral Health
https://www.readbyqxmd.com/read/28063782/acceptable-clinical-outcomes-and-recommended-reconstructive-strategies-for-secondary-maxillary-reconstruction-with-vascularized-fibula-osteomyocutaneous-flap-a-retrospective-analysis
#7
Yi Shen, Jun Li, Andrew Ow, Liang Wang, Ming-Ming Lv, Jian Sun
BACKGROUND: We conducted a retrospective analysis of the clinical outcomes and evaluated the reconstructive strategies in patients who underwent secondary maxillary reconstruction with a vascularized fibula osteomyocutaneous flap (VFOF). METHODS: From May of 2001 to June of 2014, 34 patients who underwent secondary maxillary reconstruction with VFOF, with or without titanium mesh, were reviewed. The patients were divided into two groups of maxillary reconstruction, according to different planning and treatment strategies...
December 14, 2016: Journal of Plastic, Reconstructive & Aesthetic Surgery: JPRAS
https://www.readbyqxmd.com/read/28062122/airflow-behavior-changes-in-upper-airway-caused-by-different-head-and-neck-positions-comparison-by-computational-fluid-dynamics
#8
Wei Wei, Shi-Wei Huang, Lian-Hua Chen, Yang Qi, Yi-Min Qiu, Shi-Tong Li
The feasibility of computational fluid dynamics (CFD) to evaluate airflow characteristics in different head and neck positions has not been established. This study compared the changes in volume and airflow behavior of the upper airway by CFD simulation to predict the influence of anatomical and physiological airway changes due to different head-neck positions on mechanical ventilation. One awake volunteer with no risk of difficult airway underwent computed tomography in neutral position, extension position (both head and neck extended), and sniffing position (head extended and neck flexed)...
December 29, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/28060533/morphological-distribution-of-the-anterior-inferior-iliac-spine-in-patients-with-and-without-hip-impingement
#9
George C Balazs, Benjamin C Williams, Christopher M Knaus, Daniel I Brooks, Jonathan F Dickens, Michael P McCabe, Terrence D Anderson
BACKGROUND: Subspinous impingement of the anterior inferior iliac spine (AIIS) on the femoral head-neck junction is increasingly recognized as a source of hip impingement. A classification system of AIIS morphology has previously been proposed that correlates with reduced hip motion and may predispose patients to subspinous hip impingement. PURPOSE: To examine the morphological distribution of AIIS types in patients with and without diagnosed hip impingement and correlate AIIS morphology to intraoperative findings at the time of surgery...
December 1, 2016: American Journal of Sports Medicine
https://www.readbyqxmd.com/read/28059313/speckleless-holographic-display-by-complex-modulation-based-on-double-phase-method
#10
Yijun Qi, Chenliang Chang, Jun Xia
The purpose of this study is to implement speckle reduced three-dimensional (3-D) holographic display by single phase-only spatial light modulator (SLM). The complex amplitude of hologram is transformed to pure phase value based on double-phase method. To suppress noises and higher order diffractions, we introduced a 4-f system with a filter at the frequency plane. A blazing grating is proposed to separate the complex amplitude on the frequency plane. Due to the complex modulation, the speckle noise is reduced...
December 26, 2016: Optics Express
https://www.readbyqxmd.com/read/28056140/benefits-and-limitations-of-entry-level-3-dimensional-printing-of-maxillofacial-skeletal-models
#11
Alex T Legocki, Andrew Duffy-Peter, Andrew R Scott
Importance: A protocol for creating exceptionally low-cost 3-dimensional (3-D) maxillofacial skeletal models does not require proficiency with computer software or intensive labor. Small and less affluent centers can produce models with little loss in accuracy and clinical utility. Objectives: To highlight the feasibility and methods of introducing in-house, entry-level additive manufacturing (3-D printing) technology to otolaryngologic craniofacial reconstruction and to describe its clinical applications and limitations, including a comparison with available vendor models...
January 5, 2017: JAMA Otolaryngology—Head & Neck Surgery
https://www.readbyqxmd.com/read/28052404/perineal-reconstruction-with-multiple-perforator-flaps-based-on-anatomical-divisions
#12
Joon P Hong, Chang G Kim, Hyun S Suh, Hoon Kim, Chi S Yoon, Kyu N Kim
PURPOSE: Reconstruction of perineal defects remains a challenge because such defects can be extensive, complex, and three-dimensional. This report presents a retrospective review of our past 5 years of experience in perineal reconstruction, and suggests a simple algorithmic approach according to anatomical divisions with multiple pedicled perforator flaps for extensive perineal defects. METHODS: From January 2011 to December 2015, 16 patients, including 5 men and 11 women, underwent reconstruction of extensive perineal defects...
January 4, 2017: Microsurgery
https://www.readbyqxmd.com/read/28051883/hydrogels-for-precision-meniscus-tissue-engineering-a-comprehensive-review
#13
Ana Rey-Rico, Magali Cucchiarini, Henning Madry
The meniscus plays a pivotal role to preserve the knee joint homeostasis. Lesions to the meniscus are frequent, have a reduced ability to heal, and may induce tibiofemoral osteoarthritis. Current reconstructive therapeutic options mainly focus on the treatment of lesions in the peripheral vascularized region. In contrast, few approaches are capable of stimulating repair of damaged meniscal tissue in the central, avascular portion. Tissue engineering approaches are of high interest to repair or replace damaged meniscus tissue in this area...
January 4, 2017: Connective Tissue Research
https://www.readbyqxmd.com/read/28051019/hemodynamics-in-transplant-renal-artery-stenosis-and-its-alteration-after-stent-implantation-based-on-a-patient-specific-computational-fluid-dynamics-model
#14
Hong-Yang Wang, Long-Shan Liu, Hai-Ming Cao, Jun Li, Rong-Hai Deng, Qian Fu, Huan-Xi Zhang, Ji-Guang Fei, Chang-Xi Wang
BACKGROUND: Accumulating studies on computational fluid dynamics (CFD) support the involvement of hemodynamic factors in artery stenosis. Based on a patient-specific CFD model, the present study aimed to investigate the hemodynamic characteristics of transplant renal artery stenosis (TRAS) and its alteration after stent treatment. METHODS: Computed tomography angiography (CTA) data of kidney transplant recipients in a single transplant center from April 2013 to November 2014 were reviewed...
2017: Chinese Medical Journal
https://www.readbyqxmd.com/read/28050574/a-validation-study-of-a-novel-3-dimensional-mri-modeling-technique-to-identify-the-anatomic-insertions-of-the-anterior-cruciate-ligament
#15
Catherine Hui, Yeli Pi, Vimarsha Swami, Myles Mabee, Jacob L Jaremko
BACKGROUND: Anatomic single bundle anterior cruciate ligament (ACL) reconstruction is the current gold standard in ACL reconstructive surgery. However, placement of femoral and tibial tunnels at the anatomic center of the ACL insertion sites can be difficult intraoperatively. We developed a "virtual arthroscopy" program that allows users to identify ACL insertions on preoperative knee magnetic resonance images (MRIs) and generates a 3-dimensional (3D) bone model that matches the arthroscopic view to help guide intraoperative tunnel placement...
December 2016: Orthopaedic Journal of Sports Medicine
https://www.readbyqxmd.com/read/28048865/mo-de-207a-08-four-dimensional-cone-beam-ct-iterative-reconstruction-with-time-ordered-chain-graph-model-for-non-periodic-organ-motion-and-deformation
#16
M Nakano, A Haga, J Kotoku, T Magome, Y Masutani, S Hanaoka, K Nakagawa
PURPOSE: The purpose of this study is to propose a new concept of four-dimensional (4D) cone-beam CT (CBCT) reconstruction for non-periodic organ motion using the Time-ordered Chain Graph Model (TCGM), and to compare the reconstructed results with the previously proposed methods, the total variation-based compressed sensing (TVCS) and prior-image constrained compressed sensing (PICCS). METHODS: CBCT reconstruction method introduced in this study consisted of maximum a posteriori (MAP) iterative reconstruction combined with a regularization term derived from a concept of TCGM, which includes a constraint coming from the images of neighbouring time-phases...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048567/su-c-bra-07-variability-of-patient-specific-motion-models-derived-using-different-deformable-image-registration-algorithms-for-lung-cancer-stereotactic-body-radiotherapy-sbrt-patients
#17
S Dhou, D Ionascu, J Lewis, C Williams
PURPOSE: To study the variability of patient-specific motion models derived from 4-dimensional CT (4DCT) images using different deformable image registration (DIR) algorithms for lung cancer stereotactic body radiotherapy (SBRT) patients. METHODS: Motion models are derived by 1) applying DIR between each 4DCT image and a reference image, resulting in a set of displacement vector fields (DVFs), and 2) performing principal component analysis (PCA) on the DVFs, resulting in a motion model (a set of eigenvectors capturing the variations in the DVFs)...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048523/we-de-bra-09-fast-megavoltage-ct-imaging-with-rapid-scan-time-and-low-imaging-dose-in-helical-tomotherapy
#18
T Magome, A Haga, Y Takahashi, K Nakagawa, K Dusenbery, S Hui
PURPOSE: Megavoltage computed tomography (MVCT) imaging has been widely used for daily patient setup with helical tomotherapy (HT). One drawback of MVCT is its very long imaging time, owing to slow couch speed. The purpose of this study was to develop an MVCT imaging method allowing faster couch speeds, and to assess its accuracy for image guidance for HT. METHODS: Three cadavers (mimicking closest physiological and physical system of patients) were scanned four times with couch speeds of 1, 2, 3, and 4 mm/s...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047972/tu-fg-brb-05-a-3-dimensional-prompt-gamma-imaging-system-for-range-verification-in-proton-radiotherapy
#19
E Draeger, H Chen, D Mackin, S Peterson, S Avery, S Beddar, J Polf
PURPOSE: To report on the initial developments of a clinical 3-dimensional (3D) prompt gamma (PG) imaging system for proton radiotherapy range verification. METHODS: The new imaging system under development consists of a prototype Compton camera to measure PG emission during proton beam irradiation and software to reconstruct, display, and analyze 3D images of the PG emission. For initial test of the system, PGs were measured with a prototype CC during a 200 cGy dose delivery with clinical proton pencil beams (ranging from 100 MeV - 200 MeV) to a water phantom...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047564/su-f-j-221-adjusted-dose-and-its-relation-to-radiation-induced-liver-disease-during-hepatocellular-carcinoma-radiotherapy
#20
P Huang, H Li, J Chen, C Ma, Y Gang, S Qin, Y Yin, D Li
PURPOSE: Many patients with hepatocellular carcinoma (HCC) had hepatic anatomy variations as a result of inter-fraction deformation during fractionated radiotherapy, which may result in difference from the planned dose. This study aimed to investigate the relationship between adjusted dose and radiation induced liver disease (RILD) in HCC patients receiving three dimensional conformal radiotherapy (3DCRT). METHODS: Twenty-three HCC patients received conventional fractionated 3DCRT were enrolled in this retrospective investigation...
June 2016: Medical Physics
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