Search results for "Sound"
showing 10 items of 1845 documents
Audiovisual Integration of Time-to-Contact Information for Approaching Objects.
2018
Previous studies of time-to-collision (TTC) judgments of approaching objects focused on effectiveness of visual TTC information in the optical expansion pattern (e.g., visual tau, disparity). Fewer studies examined effectiveness of auditory TTC information in the pattern of increasing intensity (auditory tau), or measured integration of auditory and visual TTC information. Here, participants judged TTC of an approaching object presented in the visual or auditory modality, or both concurrently. TTC information provided by the modalities was jittered slightly against each other, so that auditory and visual TTC were not perfectly correlated. A psychophysical reverse correlation approach was us…
Intraoperative ultrasound-assisted approach for endoscopic treatment of vesicoureteral reflux in children
2017
Purpose Despite minimal invasiveness and high success rate, guidelines still prescribe voiding Cystourethrogram (VCUG) after endoscopic treatment for vesicoureteral reflux (VUR) in children. The aim of this paper was to analyze whether intraoperative ultrasound (IO-US) could improve surgical accuracy and perioperative counseling, thus potentially decreasing the need for postoperative VCUG. Methods We selected children treated for moderate to high grade VUR, renal scarring or repeated infections under antibiotic prophylaxis from January to December 2015. Endoscopic injection was combined with IO-US to detect optimal needle placement and to guide mound formation. IO-US findings were compared …
A Survey of Prostate Segmentation Methodologies in Ultrasound, Magnetic Resonance and Computed Tomography Images
2012
Prostate segmentation is a challenging task, and the challenges significantly differ from one imaging modality to another. Low contrast, speckle, micro-calcifications and imaging artifacts like shadow poses serious challenges to accurate prostate segmentation in transrectal ultrasound (TRUS) images. However in magnetic resonance (MR) images, superior soft tissue contrast highlights large variability in shape, size and texture information inside the prostate. In contrast poor soft tissue contrast between prostate and surrounding tissues in computed tomography (CT) images pose a challenge in accurate prostate segmentation. This article reviews the methods developed for prostate gland segmenta…
Cardiovascular dysfunction and vitamin D status in childhood acute lymphoblastic leukemia survivors
2018
Vitamin D (25-OHD) has a role in bone health after treatment for cancer. 25-OHD deficiency has been associated with risk factors for cardiovascular disease, but no data focusing on this topic in childhood cancer survivors have been published. We investigated the 25-OHD status in children treated for acute lymphoblastic leukemia (ALL), and evaluated its influence on vascular function. 25-OHD levels were evaluated in 52 ALL survivors and 40 matched healthy controls. Patients were grouped according to 25-OHD level (< 20 ng/m or ≥ 20 ng/ml). Auxological parameters, biochemical and hemostatic markers of endothelial function (AD, HMW-AD, ET-1, vWFAg, TAT, D-dimers, Fbg, and hs-CRP), ultrasound ma…
Effect of large positioning holes on capsule fixation of plate-haptic intraocular lenses
2000
Abstract Purpose To compare the centration and fixation of silicone plate-haptic intraocular lenses (IOLs) with different-sized positioning holes. Setting Eye Clinic of the Johannes Gutenberg-University Mainz, Mainz, Germany. Methods In a prospective randomized study, 51 Chiroflex C10 and 56 Chiroflex C11 IOLs were implanted under standardized conditions by the same surgeon. The IOL position was documented at the end of surgery and by retroillumination on the first day and 5 months postoperatively. The positioning-hole area was evaluated by ultrasound biomicroscopy (50 MHz) 5 months postoperatively. Results One day postoperatively, no IOL in either group was decentered more than 1.0 mm. Aft…
Echocardiographic and lung ultrasound characteristics in ambulatory patients with dyspnea or prior heart failure.
2013
Purpose Lung ultrasound (LUS) represents a novel, noninvasive method in the assessment of extravascular lung water. We investigated the utility of LUS in ambulatory subjects with dyspnea or prior heart failure (HF). Methods We studied 81 ambulatory subjects with HF history or dyspnea who underwent transthoracic echocardiography (TTE) with LUS of 8 zones. Subjects with heart transplantation or pulmonary conditions known to interfere with LUS were excluded. A reviewer blinded to the clinical data performed echocardiographic measurements and quantified B-lines (reverberation artifacts arising from the pleural line). Results Of 81 subjects, 74 (91%) (median age 66 years, 39% men, median left ve…
Diagnostic accuracy of 64-slice CT in the assessment of coronary stents
2007
PURPOSE: The purpose of this study was to assess the diagnostic accuracy of 64-slice computed tomography (64-CT) coronary angiography in the detection of coronary in-stent restenosis. MATERIALS AND METHODS: Ninety-five patients (72 men and 23 women, mean age 58+/-8 years) with previous percutaneous coronary intervention with stenting and suspected restenosis underwent 64-CT (Sensation 64, Siemens). The mean time between stent deployment and 64-CT was 6.1+/-4.2 months. The scan parameters were: slices 32 x 2, individual detector width 0.6 mm, rotation time 0.33 s, feed 3.84 mm/rotation, 120 kV, 900 mAs. After the intravenous administration of iodinated contrast material (Iomeprol 400 mgI/ml,…
Acute coronary artery closure following intracoronary ultrasound examination
1995
Two patients undergoing intracoronary ultrasound examination were complicated by acute coronary artery closure. One of the complications was thought to be caused by intimal dissection and thrombus formation and the other was thought to be caused by intimal dissection and subsequent embolization. The complications were successfully managed conservatively in both cases. © 1995 Wiley-Liss, Inc.
In vitro and in vivo porphyrin accumulation by C6 glioma cells after exposure to 5-aminolevulinic acid
1998
Several malignant tissues synthesize endogenous porphyrins after exposure to 5-aminolevulinic acid (5-ALA). The present experiments have been designed to elucidate whether the C6 glioma cell, a model cell for human malignant glioma, similarly synthesizes porphyrins when exposed to 5-ALA, and whether specific synthesis occurs when C6 cells are inoculated into rat brains to form a tumor. In this situation the blood-brain barrier may interfere with 5-ALA availability, and spreading of porphyrins with edema outside the tumor may occur. Flow cytometry is used to determine the course of cell volume and porphyrin fluorescence intensities in cultured C6 cells which are incubated in 1 mM 5-ALA. For …
Transcranial magnetic resonance-guided focused ultrasound surgery at 1.5T: a technical note.
2019
Magnetic resonance-guided focused ultrasound is one of the emerging non-invasive technologies offering both image guidance and thermal monitoring. In recent years transcranial application of this technology is starting to impact heavily the neuroscience field. We present here the imaging protocol and the technological methods successfully used with a transcranial magnetic resonance-guided focused ultrasound system certified for clinical treatments of functional neurological disorders, integrated for the first time with a 1.5T magnetic resonance scanner. Compared to the body radiofrequency coil (the one commonly used with transcranial magnetic resonance-guided focused ultrasound system integ…