Search results for "Sound"
showing 10 items of 1845 documents
Ultrasonic evaluation with second harmonic imaging and SonoVue in the assessment of cerebral perfusion in diabetic patients: a case-control study
2004
The purpose was to compare human brain tissue perfusion in diabetic patients and healthy subjects with second harmonic imaging ultrasound and SonoVue to test the hypothesis that brain tissue perfusion differences are present in these two groups of patients. In a prospective case-control study, second harmonic examinations performed in 20 patients with type II diabetes mellitus and in 20 matched control patients were compared. After administration of 2.5 ml of SonoVue, 60 time-triggered images were recorded. Time-intensity curves, including peak intensity and positive gradient normalized to the middle cerebral artery, were calculated to quantify ultrasound intensity in a region of interest. …
Plantar fascia evaluation with a dedicated magnetic resonance scanner in weight-bearing position: our experience in patients with plantar fasciitis a…
2010
Purpose. This study assessed the usefulness of upright weight-bearing examination of the ankle/hind foot performed with a dedicated magnetic resonance (MR)imaging scanner in the evaluation of the plantar fascia in healthy volunteers and in patients with clinical evidence of plantar fasciitis. Materials and methods. Between January and March 2009, 20 patients with clinical evidence of plantar fasciitis (group A) and a similar number of healthy volunteers (group B) underwent MR imaging of the ankle/hind foot in the upright weight-bearing and conventional supine position. A 0.25-Tesla MR scanner (G-Scan, Esaote SpA, Genoa, Italy) was used with a dedicated receiving coil for the ankle/hind foot…
Comparison of the sympathetic skin response and continuous wave Doppler sonography of the radial artery.
1999
The value of neurophysiological tests of the autonomic nerve system is limited. One of the clinically most commonly applied test is the skin sudomotor response, frequently referred to as 'sympathetic skin response' (SSR). However, the SSR is a more qualitative than quantitative evaluation technique. Continuous wave (cw) Doppler sonography of the radial artery may be an alternative quantitative approach. We studied 41 age matched volunteers (23 female, 18 male; 16-82 years (mean age 53 years)). The stimulus was a loud and unexpected acoustic signal, alternatively a cough. SSR evaluation included the latency of onset, the duration and the amplitude of the response. Doppler evaluation also inc…
A comparison of the temporal weighting of annoyance and loudness
2009
The influence of single temporal portions of a sound on global annoyance and loudness judgments was measured using perceptual weight analysis. The stimuli were 900-ms noise samples randomly changing in level every 100 ms. For loudness judgments, Pedersen and Ellermeier [J. Acoust. Soc. Am. 123, 963-972 (2008)] found that listeners attach greater weight to the beginning and ending than to the middle of a stimulus. Qualitatively similar weights were expected for annoyance. Annoyance and loudness judgments were obtained from 12 listeners in a two-interval forced-choice task. The results demonstrated a primacy effect for the temporal weighting of both annoyance and loudness. However, a signific…
Automatic processing of rare versus novel auditory stimuli reveal different mechanisms of auditory change detection
2012
Automatic detection of rare stimuli or changes in an auditory stimulation can distract ongoing task processing by attracting attention away from task relevant information. Typically, the effectiveness of auditory change detection is tested by rare and unpredictable deviations (compared with an otherwise regular auditory presentation) or by rare environmental sounds. The present study demonstrates that both types of stimuli are capable of triggering automatic orientation of attention and that rare environmental sounds are more effective than deviations in distraction of attention. This finding suggests different mechanisms underlying the detection of auditory change. Moreover, novelty as con…
Centrifugal (inside-out) enhancement of liver hemangiomas: a possible atypical appearance on contrast-enhanced US.
2007
Abstract Objective To report the prevalence and to describe the atypical centrifugal (inside-out) appearance of contrast-enhancement of liver hemangiomas on contrast-enhanced sonography. Materials and methods Baseline and SonoVue ® -enhanced ultrasonography of 92 patients with 158 liver hemangiomas – considered atypical at grey-scale examination and confirmed by computed tomography, magnetic resonance imaging and ultrasound follow-up – were reviewed in consensus by two experienced radiologists, who evaluated baseline echogenicity and the dynamic enhancement pattern of each lesion looking for the presence of central enhancing foci in the arterial phase followed by a centrifugal (inside-out) …
Focused ultrasound to diagnose HIV-associated tuberculosis (FASH) in the extremely resource-limited setting of South Sudan: a cross-sectional study
2019
ObjectiveOur cross-sectional study aimed at evaluating the diagnostic performance of Focused Assessment with Sonography for HIV-associated tuberculosis (FASH) to detect extrapulmonary tuberculosis in extremely resource-limited settings, with visceral leishmaniasis as a differential diagnosis with overlapping sonographic feature.DesignCross-sectional study.SettingVoluntary Counselling and Testing Centre (VCT) of Yirol Hospital, South Sudan.ParticipantsFrom May to November 2017, 252 HIV-positive patients out of 624 newly admitted to VCT Centre were registered for antiretroviral treatment. According to the number of trained doctors available to practise ultrasound (US) scan, a sample of 100 pa…
Nephron-sparing surgery of renal cell carcinoma with a normal opposite kidney: long-term outcome in 180 patients
2000
Abstract Objectives. To investigate the long-term outcome of an organ-saving approach for renal cell carcinoma (RCC) with a normal opposite kidney (elective indication). Methods. Since 1979, 180 patients have undergone nephron-sparing surgery at our institution for RCC in the presence of a normal contralateral kidney. The mean age was 56 years (range 23 to 83), and the mean follow-up was 4.7 years (maximum 14.8). Most of these tumors were found incidentally, with a mean tumor diameter on ultrasound of 3.3 cm (range 1.0 to 8.6). Results. The postoperative course was unremarkable in 173 patients. Postoperative bleeding was encountered in 4 patients and urinary extravasation in an additional 3…
Intraoperative imaging findings in transcranial MR imaging-guided focused ultrasound treatment at 1.5T may accurately detect typical lesional finding…
2020
To assess the intraoperative neuroimaging findings in patients treated with transcranial MR-guided focused ultrasound (tcMRgFUS) thalamotomy using 1.5T equipment in comparison with the 48-h follow-up.Fifty prospectively enrolled patients undergoing unilateral tcMRgFUS thalamotomy for either medication-refractory essential tremor (n = 39) or Parkinson tremor (n = 11) were included. Two radiologists evaluated the presence and size of concentric lesional zones (zone I, zone II, and zone III) on 2D T2-weighted sequences acquired intraoperatively after the last high-energy sonication and at 48 h. Sonication parameters including number of sonications, delivered energy, and treatment temperatures …
Multisensorial Perception in Chronic Migraine and the Role of Medication Overuse.
2020
Multisensory processing can be assessed by measuring susceptibility to crossmodal illusions such as the Sound-Induced Flash Illusion (SIFI). When a single flash is accompanied by 2 or more beeps, it is perceived as multiple flashes (fission illusion); conversely, a fusion illusion is experienced when more flashes are matched with a single beep, leading to the perception of a single flash. Such illusory perceptions are associated to crossmodal changes in visual cortical excitability. Indeed, increasing occipital cortical excitability, by means of transcranial electrical currents, disrupts the SIFI (ie, fission illusion). Similarly, a reduced fission illusion was shown in patients with episod…