Search results for "Image"
showing 10 items of 6818 documents
Multiple Somatotopic Representations of Heat and Mechanical Pain in the Operculo-Insular Cortex: A High-Resolution fMRI Study
2010
Whereas studies of somatotopic representation of touch have been useful to distinguish multiple somatosensory areas within primary (SI) and secondary (SII) somatosensory cortex regions, no such analysis exists for the representation of pain across nociceptive modalities. Here we investigated somatotopy in the operculo-insular cortex with noxious heat and pinprick stimuli in 11 healthy subjects using high-resolution (2 × 2 × 4 mm) 3T functional magnetic resonance imaging (fMRI). Heat stimuli (delivered using a laser) and pinprick stimuli (delivered using a punctate probe) were directed to the dorsum of the right hand and foot in a balanced design. Locations of the peak fMRI responses were c…
Activation of the cortical pain network by soft tactile stimulation after injection of sumatriptan.
2006
The anti-migraine drug sumatriptan often induces unpleasant somatosensory side effects, including a dislike of being touched. With a double-blind cross-over design, we studied the effects of sumatriptan and saline on perception (visual analogue scale) and cortical processing (functional magnetic resonance imaging) of tactile stimulation in healthy subjects. Soft brush stroking on the calf (n = 6) was less pleasant (p < 0.04) and evoked less activation of posterior insular cortex in the sumatriptan compared to the saline condition. Soft brushing activated pain processing regions (anterior insular, lateral orbitofrontal, and anterior cingulate cortices, and medial thalamus) only in the sumatr…
Central opioidergic neurotransmission in complex regional pain syndrome
2010
Objective: Complex regional pain syndrome (CRPS) is a chronic pain condition characterized by sensory, motor, and autonomic symptoms. It develops after limb trauma and may be associated with relevant psychiatric comorbidity. As there is evidence for central pathophysiology which might be related to an altered opioidergic neurotransmission, we investigated the cerebral opioid receptor status under resting conditions in this patient population.Methods: In this case-control study, 10 patients with CRPS and 10 age- and gender-matched healthy subjects underwent a PET scan using the subtype-nonselective opioidergic radioligand [18F]fluoroethyl-diprenorphine. As a surrogate for regional cerebral o…
A comparative study of the pharyngeal airway space, measured with cone beam computed tomography, between patients with different craniofacial morphol…
2014
Abstract Purpose The present study aims to determine any existing association between airway dimensions, measured with cone beam computed tomography (CBCT), and the different patient craniofacial morphologies. Material and methods Sixty CBCT (Dental Picasso Master 3D) images, from patients treated at the Orthodontics Master at Valencia University were selected. The program InVivoDental 5.1 was used to visualize sections, analyze three-dimensional images, and perform airway measurements in the three planes of the space. Intra- and interobserver error methods were recorded. After that, measurements at three different levels of the airway (upper, medium, lower) were taken, in both the anteropo…
Voxel based analyses of diffusion tensor imaging in Fabry disease
2007
Background: Fabry disease (FD) is a lysosomal storage disorder that is associated with marked cerebrovascular disease. Conventional MRI shows an extensive load of white matter lesions (WMLs) already at an early stage in FD. Objective: Investigator independent and sensitive quantification of brain structural changes in clinically affected men and women with FD. Methods: The authors performed a voxel-based analysis of diffusion tensor images (DTI) in 25 FD patients and 20 age-matched normal controls. Results: DTI revealed significant increases of cerebral white matter diffusivity (MD) in FD patients that were pronounced in the periventricular white matter. Even the subgroup of patients withou…
High-b-Value Diffusion-weighted MR Imaging of Benign Hepatocellular Lesions: Quantitative and Qualitative Analysis
2012
PURPOSE:To analyze the signal intensity (SI) of benign hepatocellular lesions in high-b-value diffusion-weighted (DW) magnetic resonance (MR) images and to compare the apparent diffusion coefficient (ADC) values of focal nodular hyperplasias (FNHs) with those of hepatocellular adenomas (HCAs). MATERIALS AND METHODS: This retrospective study was approved by institutional review board, with waiver of informed consent. Inclusion criteria were consecutive patients with diagnosed FNH or HCA who underwent MR imaging with a DW sequence of the liver at three b values, 0, 150, and 600 sec/mm2. The final study population included 67 patients (seven men, 60 women) with 90 hepatocellular lesions (54 FN…
Topodiagnostic implications of hemiataxia: An MRI-based brainstem mapping analysis
2007
The topodiagnostic implications of hemiataxia following lesions of the human brainstem are only incompletely understood. We performed a voxel-based statistical analysis of lesions documented on standardised MRI in 49 prospectively recruited patients with acute hemiataxia due to isolated unilateral brainstem infarction. For statistical analysis individual MRI lesions were normalised and imported in a three-dimensional voxel-based anatomical model of the human brainstem. Statistical analysis revealed hemiataxia to be associated with lesions of three distinct brainstem areas. The strongest correlation referred to ipsilateral rostral and dorsolateral medullary infarcts affecting the inferior ce…
The effect of cigar smoking on the lingual microcirculation
2005
The aim of this study was to analyze the lingual microcirculation in vivo and to evaluate the effects on it of cigar smoking, using computerized videocapillaroscopy. Twenty-five healthy nonsmokers and 25 healthy smokers were examined. For each subject we evaluated the visibility, course, tortuosity, and any images characteristic of capillary loops, as well as the possible presence of microhemorrhages, the average caliber of the capillary loops, and the number of capillary loops visible per square millimeter. The investigation of the lingual mucosa revealed capillary loops with a course parallel to the surface. In smokers, capillary loops had a smaller caliber (P < 0.001) and there was a hig…
DNA image cytometry
1992
In 68 patients the DNA content of tumor cells was measured by image cytometry after resection of the rectum because of cancer. In the DNA histogram a differentiation between diploid (n = 19), polyploid (n = 24), hypotriploid (n = 17), and hypertriploid (n = 8) tumors was possible. The best relapse-free survival time was found in patients with diploid tumors. The prognosis worsened from polyploid to hypotriploid and was worse in hypertriploid tumors. Testing for a prognostic advantage of diploid over aneuploid tumors without adjustment for additional factors simply by means of the log-rank statistic gave a (one-sided) P of 0.1013. In a multivariate analysis the degree of differentiation turn…
Image cytometric DNA analysis of mucosal biopsies in patients with primary achalasia.
2006
(P < 0.0001), and 9c- (P = 0.0001) exceeding rate with progredient DNA alterations in the respective order. CONCLUSION: The finding that DNA aneuploidy was identifi ed by image cytometry in esophageal specimens of patients with achalasia, which may be due to specifi c chromosomal alterations presenting as precancerous lesions in 27% of patients, leads us to conclude that image cytometry represents a valuable screening tool. Abstract AIM: To determine DNA aneuploidy in mucosal biopsies of achalasia patients for subsequent rapid diagnosis. METHODS: Biopsies from the middle third of the esophagus were obtained in 15 patients with achalasia. Immunohistochemical staining was carried out with mon…