Biomed Tech (Berl)
March 2003
This article discusses the diagnostic benefit of methods for the compensation of motion artefacts in dynamic MRT-Mammography with a contrast agent. Our algorithms for motion compensation perform a locally rigid registration of cubic sub-volumes and a locally affine deformation of tetrahedral sub-volumes from a Delaunay-Triangulation. Within an extensive clinical study, these fast, automatic, and robust algorithms have been applied to 64 MRT-Mammography datasets from the radiological practice of Dr.
View Article and Find Full Text PDFDNA content, ploidy level, cell size and nuclear number were investigated in 54 mammalian hearts from nine species. DNA content was determined biochemically and ploidy level of cells was studied by the means of Feulgen cytophotometry. Nuclear number was calculated by a new method, while cell size was determined by using ocular micrometry.
View Article and Find Full Text PDFCommon manifestations of the von Hippel-Lindau syndrome, an autosomally dominant inherited cancer-prone disorder, include retinal angiomatosis, hemangioblastoma of the central nervous system, renal cysts, renal cancer, pheochromocytoma, and epididymal cystadenoma. Multiple cysts and microcystic (serous) cystadenomas of the pancreas have also been reported occasionally in patients afflicted with this syndrome. In the large Freiburg study of the von Hippel-Lindau syndrome composed of 66 affected individuals, pancreatic lesions were systematically studied.
View Article and Find Full Text PDFFifty-six patients with traumatic and 117 patients with inflammatory lesions of the knee and ankle were examined with a 2 T (69 examinations) or 0.23 T (104 examinations) MR system. The quality of all images was assessed by the consensus of three radiologists on a scale of diagnostic (3+, 2+) and nondiagnostic (1+) image quality.
View Article and Find Full Text PDFSixty-four examinations of the wrist in patients with rheumatoid arthritis by magnetic resonance imaging using a 0.23 TESLA magnet showed a great sensitivity in detecting proliferative partly exudative or destructive synovialitis, as is common in rheumatoid arthritis. In accordance to the Larsen system for grading rheumatoid arthritis lesions by conventional x-ray, we establish a clinically relevant magnetic resonance grading system which is able to diversify the stages of destruction and inflammative activity in rheumatoid arthritis.
View Article and Find Full Text PDFAlterations of magnetic resonance imaging (MRI) relaxation time and intensity can be helpful in the diagnosis of rheumatoid arthritis (RA) lesions like synovial infiltration, local inflammation and exudation. Fast low angle shot magnetic resonance imaging (FLASH-MRI) is a rapid method showing anatomy and inflammatory pathology of the examined joint comparable to late spin echo T2 images. The following study presents our results of FLASH-MRI wrist examinations of 15 patients suffering from RA according the ARA criteria and 10 healthy volunteers compared to T1 and T2 weighted MR-images and conventional X-rays.
View Article and Find Full Text PDFIn the Department of Urology, University of Freiburg, West Germany extracorporeal piezoelectric shock wave lithotripsy (EPL) has been used in the treatment of urinary and biliary stones since November 1987. The first 85 treatments (in 71 patients) for renal stones were evaluated with regard to complications and side effects. There was no need for any anesthesia.
View Article and Find Full Text PDFA fast MR sequence based on the RARE-myelographic technique allows the determination of cerebrospinal fluid (CSF) flow with a flow sensitivity below 1 mm/sec. The method averages flow over the ECG cycle and consequently measures net flow rather than ECG-dependent flow variations. The noninvasivity of this technique and the very short acquisition time of about 5 sec make this sequence a very useful diagnostic tool for a variety of CSF-flow dependent disorders like the determination of different types of hydrocephalus, the control of shunt operations and the assessment of communication pathways between CSF and cysts.
View Article and Find Full Text PDFNMR Biomed
December 1989
It is demonstrated that it is possible to acquire two volume selective 1H NMR spectra of human brain in vivo, consisting of voxels of 1.5 X 1.5 X 1.
View Article and Find Full Text PDFThe exact radiographic localisation of supraganglionic lesions of the brachial plexus provides important information for the prognosis and clinical management of these injuries. The authors report on the results of enhanced CT scanning and MRI of the cervical spine in five patients with surgically proven root avulsions caused by traction injuries. All lesions were correctly diagnosed by enhanced CT scanning.
View Article and Find Full Text PDFThe findings of a 10-year study (1976 to 1986) conducted in southwest Germany on hemangioblastomas (HBL's) of the central nervous system (CNS) are presented. During that period, 47 HBL's were diagnosed and surgically removed in 44 patients, with a good postoperative survival rate and prognosis. The majority (83%) of these tumors were located in the cerebellum.
View Article and Find Full Text PDFMarked portosystemic venous anastomosis of the parumbilical veins is referred to as the Cruveilhier-Baumgarten syndrome. Opening of these vessels has been described mainly in the sonographic literature. In this case report CT and MR findings are presented, which have been confirmed by angiography.
View Article and Find Full Text PDFUltrasonography and computed tomography are widely used for the diagnosis of focal lesions of the liver. However, the possibilities for tumor characterization and determination of potential malignancy are limited in many cases. Evaluation by magnetic resonance imaging shows a good correlation of relaxation time with the amount of stroma as a proportion of the total cell content of a lesion.
View Article and Find Full Text PDFMagn Reson Imaging
November 1988
The RARE technique is an extremely useful tool for clinical diagnosis, since it delivers images comparable to those produced by X-ray myelography and X-ray urography. Contrary to these methods, RARE does not use the application of contrast agents. A low-flip-angle variant called FLARE (fast low angle refocused echo imaging) makes this technique accessible for high-field systems.
View Article and Find Full Text PDFMagn Reson Imaging
November 1988
The fast Fourier flow technique offers a convenient way for extremely exact flow measurements. In combination with ECG gating, arterial flow can be studied. The total acquisition time for a single measurement is about 10 s, an ECG-gated cine sequence can be acquired in about 4 min.
View Article and Find Full Text PDFThe fast Fourier flow method of magnetic resonance (MR) imaging offers a fast and efficient way of measuring quantitative flow for velocities within the range from several millimeters per second to more than 1 m/sec. When fast Fourier flow imaging is used in combination with echocardiographic gating, arterial flow can be determined and velocity versus time profiles can be generated. Because of the high spatial resolution, down to 0.
View Article and Find Full Text PDFPotentials and limitations of a new, facultative non-tomographic Fast-Imaging sequence "RARE-MR-Urography" are presented. Its results in urological diseases are discussed on the basis of a pilot study of 35 patients. The images (4 s-32 s acquisition time) are extremely T2-weighted and display unbounded free water (urine).
View Article and Find Full Text PDFThe RARE method is based on the principle of echo imaging to generate images with high T2 contrast. Since RARE is a fast imaging method, it can be used to acquire a high-resolution three-dimensional data set in less than 15 min. Thin slices from such a three-dimensional data set provide detailed information about the ventricular system.
View Article and Find Full Text PDFA report on the application of standard 2D-FT MR combined with RARE-MR-Urography in a pregnant woman with right sided abdominal pain, dilated upper urinary tract and possible stone or inflammatory disease. This technique visualised the complete obstructed ureter in relation to the surrounding organs (uterus, vessels), allows precise diagnosis of the cause of the obstruction and avoids ionising radiation.
View Article and Find Full Text PDFJ Comput Assist Tomogr
November 1987
The steady state selective saturation method is a fast and efficient technique to study flow with magnetic resonance imaging. The pulse sequence used generates no signal from stationary matter and simultaneously optimizes signal flowing into a predetermined volume. The method can be used to generate three-dimensional angiography in less than 5 min.
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