Search results for "RESONANCE"
showing 10 items of 6625 documents
VBM-DTI correlates of verbal intelligence: a potential link to Broca's area.
2012
Abstract Human brain lesion studies first investigated the biological roots of cognitive functions including language in the late 1800s. Neuroimaging studies have reported correlation findings with general intelligence predominantly in fronto-parietal cortical areas. However, there is still little evidence about the relationship between verbal intelligence and structural properties of the brain. We predicted that verbal performance is related to language regions of Broca's and Wernicke's areas. Verbal intelligence quotient (vIQ) was assessed in 30 healthy young subjects. T1-weighted MRI and diffusion tensor imaging data sets were acquired. Voxel-wise regression analyses were used to correla…
Functional MRI of galvanic vestibular stimulation with alternating currents at different frequencies.
2004
Abstract Functional MRI was performed in 28 healthy volunteers to study the effects of galvanic vestibular stimulation with alternating currents (AC-GVS) of different frequencies on brain activation patterns. The aims of this study were (1) to identify specific areas within the vestibular cortical network that are involved in the processing of frequency-specific aspects by correlation analyses, (2) to determine the optimal frequency for stimulation of the vestibular system with respect to perception, and (3) to analyze whether different frequencies of AC-GVS are mediated in different cortical areas or different sites within the vestibular cortex. AC-GVS was performed using sinusoidal stimul…
Cortical representation of saccular vestibular stimulation: VEMPs in fMRI
2006
Short tone bursts trigger a vestibular evoked myogenic potential (VEMP), an inhibitory potential which reflects a component of the vestibulocollic reflex (VCR). These potentials arise as a result of activation of the sacculus and are expressed through the vestibulo-collic reflex (VCR). Up to now, the ascending projections of the sacculus are unknown in humans, only the representation of the semicircular canals or the entire vestibular nerve has been demonstrated. The aim of this study was to determine whether a sacculus stimulus that evoked VEMPs could activate vestibular cortical areas in fMRI. To determine this, we studied the differential effects of unilateral VEMP stimulation in 21 heal…
Modulating phonemic fluency performance in healthy subjects with transcranial magnetic stimulation over the left or right lateral frontal cortex.
2017
Abstract A growing body of evidence have suggested that non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), can improve the performance of aphasic patients in language tasks. For example, application of inhibitory rTMS or tDCs over the right frontal lobe of dysphasic patients resulted in improved naming abilities. Several studies have also reported that in healthy controls (HC) tDCS application over the left prefrontal cortex (PFC) improve performance in naming and semantic fluency tasks. The aim of this study was to investigate in HC, for the first time, the effects of inhibitory repetitive TMS (rTMS…
Colorectal Polyps: Detection with Dark-Lumen MR Colonography versus Conventional Colonoscopy
2005
To prospectively compare dark-lumen magnetic resonance (MR) colonography with conventional colonoscopy in the detection of colorectal polyps.Local ethical committee approval and informed consent were obtained. One hundred consecutive patients (56 men, 44 women; mean age +/- standard deviation, 67.7 years +/- 14.7; range, 25-82 years) who were referred for conventional colonoscopy from January 2003 to January 2004 underwent MR colonography and conventional colonoscopy after standard precolonoscopic bowel cleansing. Colonoscopy was performed immediately after MR colonography. For MR colonography, the colon was filled with approximately 2000 mL of tap water. Imaging was performed with a 1.5-T …
Solitary rectal ulcer: ultrasonographic and magnetic resonance imaging patterns mimicking rectal cancer.
2011
The objective of this study was to analyze a series of solitary rectal ulcer syndrome (SRUS) cases initially diagnosed as rectal cancer. We analyzed all the patients (1996-2008) initially referred to our colorectal unit with a diagnosis of rectal cancer but with a final diagnosis of SRUS. Demographic data, the diagnostic work-up, and treatment details were collected in a prospective database and analyzed retrospectively. Out of the 5035 patients registered in the colorectal unit database, 14 (0.28%) had a final diagnosis of SRUS. Nine of them had an initial diagnosis of rectal cancer. Out of these, six were preoperatively staged with endorectal ultrasound and/or magnetic resonance and were …
Evaluation of Mesorectal Fascia in Mid and Low Anterior Rectal Cancer Using Endorectal Ultrasound Is Feasible and Reliable
2014
Accuracy of MRI in assessing mesorectal fascia and predicting circumferential resection margin decreases in low anterior rectal tumors.The purpose of this work was to evaluate the accuracy of endorectal ultrasound in predicting the pathologic circumferential resection margin in low rectal anterior tumors and to compare it with MRI findings.This was a prospective series comparing the preoperative circumferential resection margin assessed by endorectal ultrasound and MRI with pathologic examination.The study was conducted by a specialized colorectal multidisciplinary team at a tertiary teaching hospital.Between 2002 and 2008, 76 patients with mid to low rectal cancer were preoperatively evalu…
Modified Wong's Classification Improves the Accuracy of Rectal Cancer Staging by Endorectal Ultrasound and MRI
2013
BACKGROUND: Douglas Wong proposed a new classification of tumor penetration in the rectal wall (T stage) in an attempt to incorporate the prognostic heterogeneity of T3 rectal cancers into the preoperative staging. OBJECTIVE: This study aimed to evaluate if the accuracy of endorectal ultrasound and MRI in predicting rectal cancer T staging improves when using a modified Wong's classification. DESIGN: This prospective series compares local standard TN staging and a modified Wong's classification. SETTINGS: This study was conducted by a specialized Colorectal Multidisciplinary Team at a tertiary teaching hospital. PATIENTS: Seventy patients underwent surgery for middle or low rectal cancer be…
Avoidance of Overtreatment of Rectal Cancer by Selective Chemoradiotherapy: Results of the Optimized Surgery and MRI-Based Multimodal Therapy Trial.
2020
Background Neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer carries a high risk of adverse effects. The aim of this study was to examine the selective application of nCRT based on patient risk profile, as determined by MRI, to find the optimal range between undertreatment and overtreatment. Study Design In this prospective multicenter observational study, nCRT before total mesorectal excision (TME) was indicated in high-risk patients with involved or threatened mesorectal fascia (≤1 mm), or cT4 or cT3 carcinomas of the lower rectal third. All other patients received primary surgery. Results Of the 1,093 patients, 878 (80.3%) were treated according to the protocol, 526 pat…
A multicenter, site-independent, blinded study to compare the diagnostic accuracy of contrast-enhanced magnetic resonance angiography using 1.0M gado…
2007
Abstract Purpose Prospective evaluation of diagnostic accuracy of single field-of-view contrast-enhanced MR Angiography (ceMRA) with 1.0 M gadobutrol compared to intraarterial DSA in body arteries. Materials and methods In an European multicenter study 179 patients underwent ceMRA and DSA. For each indication five prospectively defined vessel segments were evaluated by local investigators onsite and by three site-independent blinded readers (BR) independently. Results The agreement between ceMRA and DSA diagnosis was statistically significant in the onsite (96.6%) and blinded reader (86.6–90.2%) evaluation. Sensitivity, specificity, accuracy, positive (PPV) and negative predictive values (N…