Search results for "aging"
showing 10 items of 10496 documents
Third nerve palsy as the sole manifestation of midbrain ischemia
1995
Thirty-seven patients with risk factors for the development of cerebrovascular diseases had sudden onset isolated third nerve palsy and abnormal masseter reflex and/or electro-oculographic findings indicating a causative midbrain lesion. Improvement or recovery of the third nerve palsies was accompanied by improvement or recovery of the abnormal electrophysiologic findings pointing to their functional significance. Magnetic resonance imaging (MRI) in 29 of these patients demonstrated corresponding ischemic midbrain lesions in eight, ipsilateral in five patients, bilateral in three. In another three patients with MRI proven midbrain lesions (ipsilateral in two, bilateral in one) electrophysi…
Focal liver lesions hyperintense on T1-weighted magnetic resonance images.
2009
This article reviews focal liver lesions hyperintense on T1-weighted magnetic resonance (MR) images and describes the underlying etiologies associated with their T1 signal intensity. Although focal liver lesions are commonly detected because of their iso- or hypointensity on T1-weighted images, lesions (benign or malignant) may present with T1 hyperintensity when they contain T1 shortening elements--such as fat, hemorrhage, copper, melanin, and highly concentrated proteins. Our discussion includes the description of state-of-the-art T1-weighted MR sequences and the imaging features of lesions on pre- and postcontrast MR images that are characteristic for lesion composition and useful for ma…
Liver intravoxel incoherent motion (IVIM) magnetic resonance imaging: a comprehensive review of published data on normal values and applications for …
2017
A comprehensive literature review was performed on liver intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) technique and its applications. Heterogeneous data have been reported. IVIM parameters are magnetic field strength dependent to a mild extent. A lower Dslow (D) value at 3 T than at 1.5 T and higher perfusion fraction (PF) value at 3 T than at 1.5 T were noted. An increased number of b values are associated with increased IVIM parameter measurement accuracy. With the current status of art, IVIM technique is not yet capable of detecting early stage liver fibrosis and diagnosing liver fibrosis grades, nor can it differentiate liver tumors. Though IVIM parameters show p…
Messung des Gefäßdurchmessers zur Bestimmung von Stent- und Ballongröße bei perkutanen Eingriffen an der Beckenstrombahn
1995
AIM Should the sizes of balloons and stents used in the pelvic circulation be determined by the size of the ipsilateral or contralateral vessel? STUDY DESIGN The angiographic findings in 31 patients were analysed; in 10 an occlusion and in 21 a high grade stenosis (greater than 75%) of the common iliac artery had been treated by stenting (26) or simple PTA (5). RESULTS In 26 of the 31 patients there was marked reduction in the lumen distal to the lesion up to 40%. In 17 patients this was reversed immediately after the procedure and in five others the lumen increased but a difference between the two sides remained. The changes on the two sides following treatment were statistically significa…
Lung ventilation- and perfusion-weighted Fourier decomposition magnetic resonance imaging: In vivo validation with hyperpolarized3He and dynamic cont…
2012
The purpose of this work was to validate ventilation-weighted (VW) and perfusion-weighted (QW) Fourier decomposition (FD) magnetic resonance imaging (MRI) with hyperpolarized (3)He MRI and dynamic contrast-enhanced perfusion (DCE) MRI in a controlled animal experiment. Three healthy pigs were studied on 1.5-T MR scanner. For FD MRI, the VW and QW images were obtained by postprocessing of time-resolved lung image sets. DCE acquisitions were performed immediately after contrast agent injection. (3)He MRI data were acquired following the administration of hyperpolarized helium and nitrogen mixture. After baseline MR scans, pulmonary embolism was artificially produced. FD MRI and DCE MRI perfus…
Delayed MRI Hyperenhancement in Noncompaction: Sign of Fibrosis Correlated with Clinical Severity
2008
N.A.
Whole-body MRI, FDG-PET/CT, and bone marrow biopsy, for the assessment of bone marrow involvement in patients with newly diagnosed lymphoma
2016
Purpose To compare whole-body MRI (WB-MRI) with diffusion-weighted imaging (DWI), FDG-PET/CT, and bone marrow biopsy (BMB), for the evaluation of bone marrow involvement (BMI) in patients with newly diagnosed lymphoma. Materials and Methods This retrospective study was approved by our Institutional Review Board. Two independent radiologists and one nuclear medicine specialist reviewed all WB-MRI and FDG-PET/CT scans prospectively performed on 104 patients with newly diagnosed lymphoma (53 males; 47 Hodgkin; mean age: 44 years; range, 15–86 years) between 2013 and 2015. The delay between imaging scans and BMBs was up to 10 days. The diagnostic accuracy of WB-MRI (1.5 Tesla MR scanner, with T…
Differentiation between brain metastases and glioblastoma multiforme based on MRI, MRS and MRSI
2009
Brain metastases and glioblastoma multiforme are the most aggressive and common brain tumours in adults and they require a different clinical management. Anatomical magnetic resonance imaging (MRI) or clinical history, cannot always clearly distinguish between them. This study describes and verifies the use of magnetic resonance spectroscopy (MRS) and magnetic resonance spectroscopic imaging (MRSI) in combination with MRI for differential diagnosis of glioblastomas and metastases. Feature selection methods are applied to the magnetic resonance (MR) spectra of 121 patients and relevant features are detected. Different classification methods are used to distinguish glioblastoma multiforme and…
Spiral-Computertomographie der Mamma
1994
Aim To evaluate the use of spiral CT in the diagnosis of breast lesions. Material and methods 93 female patients with suspicious or uncertain mammographic findings were examined by CT before and after contrast enhancement according to the following practical method: table movement, 6 mm/s, slice thickness 6 mm, increment 4 mm, contrast 200 ml, injection rate 3 ml/s, scan start 50 s after the beginning of the injection. Histological confirmation was present in 85 patients. Results All 44 invasive carcinomas were recognised. They were characterised by intensive focal contrast uptake. Only 2 out of 7 intraductal carcinomas were not shown by CT. 36 out of 38 benign lesions were correctly diagno…
Gegenwärtiger Stellenwert der perkutanentranshepatischen Cholangiodrainage
2002
Percutaneous transhepatic biliary drainage (PTBD) is a well established method in the treatment of obstructive jaundice. Major indications are malignant diseases. PTBD may be necessary preoperatively in cases with severe jaundice or cholangitis or as part of palliative treatment concepts. In the past, it has been proposed that a period of preoperative PTBD may improve the morbidity rates of surgery. Various studies could not prove this theory. The significance of preoperative PTBD has changed, as observed during a 15 years period in our own institution, the indications for preoperative PTBD have decreased by half. At present, the majority of treatments with PTBD are palliative (almost 70 % …