Search results for "Circulation"
showing 10 items of 1137 documents
Assessment of tumor microcirculation with dynamic contrast-enhanced MRI in patients with esophageal cancer: initial experience.
2008
PURPOSE: To investigate the feasibility and impact of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) on tumor characterization and response to radiochemotherapy (RCT) in patients with esophageal cancer. MATERIALS AND METHODS: A total of 48 patients underwent DCE-MRI to assess tumor microcirculation based on a two-compartment model function. Effects of RCT on kinetic parameters were studied in 12 patients with squamous cell carcinoma. RESULTS: Tumor microcirculation differs with respect to histological subtype: squamous cell carcinomas showed lower values of amplitude A (leakage space, P = 0.015) and higher contrast agent exchange rates (k(21), P = 0.225) compared with adenoc…
Dynamic contrast-enhanced myocardial perfusion imaging using saturation-prepared TrueFISP.
2002
Purpose To develop and test a saturation-recovery TrueFISP (SR-TrueFISP) pulse sequence for first-pass myocardial perfusion imaging. Materials and Methods First-pass magnetic resonance imaging (MRI) of Gd-DTPA (2 mL) kinetics in the heart was performed using an SR-TrueFISP pulse sequence (TR/TE/α = 2.6 msec/1.4 msec/55°) with saturation preparation TD = 30 msec before the TrueFISP readout. Measurements were also performed with a conventional saturation-recovery TurboFLASH (SRTF) pulse sequence for comparison. Results SR-TrueFISP images were of excellent quality and demonstrated contrast agent wash-in more clearly than SRTF images. The signal increase in myocardium was higher in SR-TrueFISP …
Correlation of " in vivo" microcirculation and degeneration of the basal cells of the epithelium in lingual lichen planus
2010
Background: Oral lichen planus is an inflammatory chronic disease with an autimmune pathogenesis and unknown etiology that affects oral mucosa, with or without the involvement of the skin and other mucous membranes. The principal histological characteristics are the degeneration of the basal cell layer and the abnormal infiltration of inflammatory cells into the subepithelial layer of connective tissue. Objectives: This study is aimed to appraise if lingual lichen planus (LLP) is sustained by alteration of the oral microcirculation and if this abnormal vascularisation increases the degeneration of basal keratinocytes and the disruption of the basement membrane. Materials and Methods: Fiftee…
Short- and long-term effects of the transjugular intrahepatic portosystemic shunt on portal vein thrombosis in patients with cirrhosis
2011
Background and aims Portal vein thrombosis (PVT) negatively impacts the prognosis in patients with cirrhosis. The aim of our study was to evaluate the effects of transjugular intrahepatic portosystemic shunt (TIPS) placement in patients with cirrhosis complicated by PVT. Methods Seventy consecutive cirrhotic patients with non-tumoural PVT treated with TIPS for portal hypertension complications from January 2003 to February 2010 in a tertiary-care centre were followed until last clinical evaluation, liver transplantation, or death. Results TIPS was successfully placed without major procedure-related complications. After TIPS, the portal venous system was completely recanalised in 57% of pati…
Correlation of cerebral blood flow and MCA flow velocity measured in healthy volunteers during acetazolamide and CO2 stimulation
1995
Abstract The assessment of the cerebrovascular reserve capacity (RC) has become a widely used tool in the management of cerebrovascular disease. Discrepancies become obvious, however, if results obtained with different methods are compared. Aim of the present study, therefore, was to compare blood velocity and cerebral perfusion data in the same group of healthy test persons. In 32 volunteers regional cerebral blood flow (rCBF) was measured with the 133 Xe-inhalation method. F1 as grey matter flow and the initial slope index (ISI) were computed. Simultaneously flow velocity in the middle cerebral artery (V MCA ) was assessed by transcranial Doppler sonography (TCD). Measurements were perfor…
The Effects of Isoflurane and Desflurane on Intracranial Pressure, Cerebral Perfusion Pressure, and Cerebral Arteriovenous Oxygen Content Difference …
2003
Background Desflurane is a volatile anesthetic agent with low solubility whose use in neurosurgery has been debated because of its effect on intracranial pressure and cerebral blood flow. The purpose of this study was to determine the variations on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) as well as on cerebral arteriovenous oxygen content difference (AVDo(2)) in normocapnic patients scheduled to undergo removal of supratentorial brain tumors with no evidence of mass effect during anesthesia with isoflurane or desflurane. Methods In 60 patients scheduled to undergo craniotomy and removal of supratentorial brain tumors with no evidence of midline shift, anesthesia w…
Cerebral blood flow velocities after subarachnoid haemorrhage in relation to the amount of blood clots in the initial computed tomography.
1998
In 72 patients with acute subarachnoid haemorrhage (SAH) the relationship between the amount of subarachnoid blood clots detected by initial cranial computed tomography (CCT) up to 48 hours after bleeding and the later development of vasospasm, established by blood flow velocity measurement with transcranial Doppler ultrasound (TCD) was investigated. The serial Doppler examinations started within the first 72 hours after SAH and were carried out every second day up to three weeks. Each Doppler recording was accompanied by a neurological examination. Patients classified as Hunt and Hess grade V were excluded from the study. All patients with remarkable brain oedema in CCT or with intracrania…
Mitral and aortic regurgitation in 84 patients with mucopolysaccharidoses
1995
In echocardiographic and necropsy studies nodular thickening of the mitral valve and, less frequently, of the aortic valve has been found in 60%-90% of patients with mucopolysaccharidoses (MPS). Little is known about the haemodynamic consequences of these morphological changes. In this study 84 unselected patients with different enzymatically proven MPS and 84 age and sex matched, healthy persons were studied prospectively by colour Doppler flow mapping. The patients' age ranged from 1 to 47 years (median 8.1 years). Mitral and aortic regurgitation were defined as a holosystolic or holodiastolic jet originating from the valve into the left atrium or the left ventricular outflow tract, respe…
Tc-99m HMPAO Cerebral Scintigraphy A Reliable, Noninvaslve Method for Determination of Brain Death
1993
To determine the usefulness of cerebral blood flow imaging for the diagnosis of brain death, 4 female and 12 male patients, aged 19 to 69 years and suffering from various intracranial lesions, were studied. In addition to neurologic examination, electroencephalographic recording, and cerebral angiography, tomographic brain scintigraphy was performed using a SPECT system with a LEAP collimator after the intravenous administration of 555 MBq Tc-99m HMPAO. The radioisotopic scanning procedure revealed no intracranial perfusion in 14 of the 16 patients. Only minimal cerebellar blood flow was seen in one patient. In another, residual right-sided supratentorial flow was initially present but abse…
Contrast-enhanced transcranial Doppler ultrasonography in the diagnosis of brain death
2013
The diagnosis of brain death (BD) is based on clinical criteria including deep coma, brain stem areflexia and apnoea. Depending on different local guidelines, confirmatory technical tests are sometimes mandatory.1 Since the 1990s, transcranial Doppler sonography (TCD) has found its place in these circumstances and fulfils most of the criteria of an ‘ideal test’ in confirming BD. To confirm intracranial circulatory arrest (CA) with Doppler sonography, typical flow patterns must be recorded in bilateral intracranial and extracranial brain-supplying arteries.2 A completely absent intracranial flow signal is not a reliable sign to determine CA because this can be due to transmission problems. I…