Search results for "Ultrasound"
showing 10 items of 1259 documents
Color-coded duplex ultrasonography of the origin of the vertebral artery: normal values of flow velocities.
2000
The introduction of color-coded duplex ultrasonography has improved the ease of performing ultrasound investigations of the vertebral arteries. So far, normal values of flow velocities have been reported only for the intertransverse region of the vertebral artery (V2 segments). Atherosclerotic disease at the origin of the vertebral arteries (V0 segment) is frequent and is one of the risk factors for vertebrobasilar ischemic disease. Normal values of flow velocities of the vertebral artery origin are needed to assess pathologic findings, such as vertebral artery origin stenosis or dissection. The aim of this study was to describe the normal flow velocities of vertebral artery origin (V0 segm…
'Prefrontal' cognitive performance of healthy subjects positively correlates with cerebral FDOPA influx: an exploratory [18F]-fluoro-L-DOPA-PET inves…
2006
Dopamine neurotransmission influences those cognitive processes, which are generally regarded as prefrontal cortical functions. In previous positron‐emission‐tomography (PET) studies, net blood‐brain clearance of [(18)F]‐fluoro‐l‐DOPA (FDOPA) correlated with impaired cognitive performance in patients with Parkinson's disease or schizophrenia. We hypothesized that FDOPA influx also correlates with performance of cognitive tasks associated with prefrontal functioning in healthy volunteers. The net blood‐brain clearance of FDOPA (K [Formula: see text]) was mapped in a group of 11 healthy volunteers and calculated in striatal volumes‐of‐interest. The Wisconsin‐Card‐Sorting‐Test (WCST), Stroop‐T…
Enteroscopy and its relationship to radiological small bowel imaging
2009
The field of radiological small bowel imaging is changing rapidly, as is small bowel enteroscopy. New techniques allow the depiction of intraluminal, mural, and extraintestinal features of various small bowel disorders, such as Crohn disease, small bowel polyposis syndromes, small intestinal malignancies, and celiac disease. For patients requiring repeated small bowel imaging, modalities that do not use ionizing radiation, such as ultrasound or magnetic resonance imaging, should be considered.
Echogenicity of the substantia nigra in relatives of patients with sporadic Parkinson’s disease
2003
Increased echogenicity of the substantia nigra (SN) on ultrasound is a typical sonographic finding in Parkinson's disease (PD). Sonographic signal intensity of the SN is related to tissue iron content with higher iron level being associated with increased echogenicity. Recent findings indicate that hyperechogenicity of the SN represents an important susceptibility factor for nigrostriatal degeneration. In this study we determined the prevalence of a characteristic ultrasound sign of Parkinson's disease in first-degree relatives of PD patients. Fourteen patients with sporadic PD and 58 of their relatives underwent neurological, neuropsychological, and ultrasound examination. In addition, fou…
Real-time spatial compound sonography of Achilles tendon in patients with heterozygous familial hypercholesterolaemia and normal physical examination
2007
This study was undertaken to assess the prevalence and ultrasound features of Achilles tendon xanthomas (ATX) in patients with heterozygous familial hypercholesterolemia (HFH) and normal physical examination studied with high-resolution ultrasonography (HRUS) and, secondarily, to evaluate the role of real-time spatial compound sonography (CS) in terms of image quality.Both Achilles tendons of 40 patients with HFH were studied with HRUS and CS. Two experienced radiologists evaluated by consensus the presence of ATX described as (1) tendon thickening and/or (2) focal hypoechoic areas and the quality of images obtained with the two techniques.Ten out of 80 tendons showed thickening (mean: 11.2…
In vivo ultrasound real-time motion of the cervical spine during intubation under manual in-line stabilization: a comparison of intubation methods
2007
Background and objectiveIn emergency trauma situations, manual in-line stabilization of the cervical spine is recommended to reduce cervical spine movement during intubation. The aim of this study was to compare the effect of manual in-line stabilization during different intubation techniques on three-dimensional cervical spine movements and times to intubation.MethodsForty-eight subjects without any history of trauma, inflammatory or degenerative disorder of the cervical spine were randomly grouped, regardless of gender or age. All underwent elective surgery under general anaesthesia. Under manual in-line stabilization, laryngeal intubation with Macintosh laryngoscope, intubating laryngeal…
Muscle tone in different joint positions and at submaximal isometric torque levels
2007
The aim was to evaluate the tone and electric activity of the quadriceps muscle at rest and different torque levels. The second aim was to study whether thickness of soft tissues and change in the joint position would affect muscle tone. Eighteen healthy subjects participated. Computerized muscle tonometer (CMT) and surface electromyography (sEMG) measurements were performed: seated, first at rest with leg straight and then with the knee at 60 degrees . Thereafter measurements were obtained at levels of 80, 60, 40 and 20% of the maximum isometric torque at the same knee angle. Thickness of skin, subcutis and muscle was measured by ultrasound. The CMT values taken were the depth the indenter…
Transthoracic three-dimensional echocardiographic volumetry of distorted left ventricles using rotational scanning
1997
The purpose of this study was to evaluate the relation of transthoracic three- and two-dimensional echocardiographic left ventricular volumetry to cineventriculographic volumetry. Twenty-five patients with distorted left ventricles were included in the study. To demonstrate the impact of acquiring data by rotational scanning, we performed three- and two-dimensional echocardiography in 36 latex ventricles with data acquisition in different areas of the ultrasound sectors. Interobserver and intraobserver variability were calculated to test for reproducibility. The three-dimensional imaging system consisted of a rotation motor device, a transthoracic 2.5 MHz transducer, a conventional ultrasou…
Dynamic angular three-dimensional measurement of multisegmental thoracolumbar motion in vivo.
2008
Study design Method validation and in vivo motion segment study. Objective To determine in healthy subjects in vivo intervertebral segmental kinematics and coupled motion behavior in all 3 planes simultaneously for 3 segments and to evaluate whether these results differ from those in the normal population according to the literature. Summary of background data Few studies have provided a direct invasive approach to investigate segmental kinematics in vivo. Dynamic recordings of 3-dimensional segmental motion patterns of adjacent segments have rarely been reported. To date, no studies have examined the 3-dimensional segmental movements of the thoracolumbar junction in vivo in detail. Methods…
Autism is a prenatal disorder: Evidence from late gestation brain overgrowth.
2018
This retrospective study aimed to specify the critical period for atypical brain development in individuals with autism spectrum disorder (ASD) using prenatal and postnatal head growth parameters. The sample consisted of 80 Caucasian, unrelated, idiopathic patients with ASD born after 1995. Fetal ultrasound parameters (head circumference [HC], abdominal circumference, and femur length) were obtained during the second and third trimesters of gestation. HC at birth and postnatal parameters at 12 and 24 months of age were also collected. Head overgrowth, assessed by HC, was highlighted during the second (20-26 weeks of amenorrhea) and third (28-36 weeks of amenorrhea) trimesters. Normal growth…