Digitale Bilddiagnostik最新文献

Sialography is at present performed either by the subtraction mode or conventional technique only. We utilised a high-resolution digital radiography system with a 1024 x 1024 matrix in 17 patients with diseases of the salivary glands. Digital subtraction ductography in lateral projection was followed by digital radiography in adequate projections. In that way advantages of both methods could be combined in one. Additional advantages are possibilities of storage and communication of the digital data.

A Turbo FLASH sequence consisting of an initial non-selective 180 degree inversion pulse followed by an ultrafast FLASH sequence with very short repetition and echo times (TR = 7 ms, TE = 4 ms) was used to study 20 patients with focal liver lesions. The results were compared to T1-weighted gradient-echo (108/5/80 for TR/TE/flip angle) and T2-weighted spin-echo sequences (TR/TE/excitations = 2500 ms/40 ms, 90 ms, 140 ms/2). Liver-spleen contrast of the fast scans was superior to T1- and T2-weighted images for TI = 300 ms (0.59 +/- 0.12 vs 0.33 +/- 0.07 and 0.42 +/- 0.14 respectively). Liver-lesion contrast of the fast scans for TI = 300-700 ms was superior to the T1-weighted gradient echo sequence (0.49 +/- 0.21 vs 0.23 +/- 0.09), equal to the T2-weighted spin echo sequence for TE = 90 ms (0.54 +/- 0.17) but inferior to the 140 ms echo (0.63 +/- 0.18). On Turbo FLASH scans, there were no flow or motion artifacts and lesions borders and structures were better delineated than on the spin-echo images. Imaging time for the whole liver is less than a minute.

15 patients with asymptomatic abdominal aortic aneurysms were evaluated with magnetic resonance imaging. The results were compared to the sonographic findings in 12, the computed tomographic in 14 and the angiographic findings in 14 cases. 14 patients were operated and the diagnostic results were verified. The advantage of MRI in comparison with the other diagnostic methods is the visualization of an infrarenal segment on the coronal images, which can be anastomized with the vascular prosthesis. The evidence of this segment is important to know for the vascular surgeon to plan the operation technique. The disadvantage of MRI ist that thrombotic material and arteriosclerotic plaques were bad or not visualized. We try to estimate, which importance the MRI will get in further times in the preoperative diagnosis of abdominal aortic aneurysms.

Generation, transfer and reception of sensory information in the human body is established by electric events, a multitude of current pulses propagating electric events, a multitude of current pulses propagating through the nervous system and muscles. Today, medical diagnosis is based on recording the electric potentials created by these pulses--ECG or EEG--with electrodes on the skin or invasively with catheters. In addition, the magnetic field generated simultaneously allows a sufficiently precise localisation of single events as well as current trains. By fusion with three dimensional anatomic images, sources and propagation of electrical activity can be visualised in biomagnetic images with resolution in space as well as in time. These prospects resulted in a continuing interest in biomagnetism (BM) even though specific equipment for the detection of magnetic field patterns was not available. Technological progresses recently allowed systems containing many, integrated, highly sensitive sensors to be developed. These are quite large enough to cover the area over the human skull and heart. The registration of magnetic field patterns in one shot allows localisation of sporadic events and reduces the time for data acquisition to a few minutes. In addition to explaining the characteristics of BM fields and modern techniques for their registration this paper focuses on the results of pilot studies, performed during the last 2 years with multichannel systems. It was shown that sufficient correlation exists to normal physiology. Pathology was studied mainly in heart diseases and in epilepsy.

In an attempt to optimize renal artery angiography we performed a CT-study. In 500 patients we determined the angle at which the arteries arise from the aorta and their course. Both renal arteries are in one plane, which is tilted 13 degrees ventrally on the right and 13 degrees dorsally on the left. More distally we found an angle of 35 degrees on the right and an angle of 29 degrees on the left in the dorsal direction. These findings were independent of age and sex of the patient.

Our study includes 15 posttransplant angiographies in 10 patients after liver transplantation and 3 cases with embolisation of the splenic artery because of a splenohepatic steal syndrome. The results of the angiographies are demonstrated and discussed. In cases with non-conclusive ultrasound or CT findings, angiography is the method of choice, if an arterial anastomotic complication or a chronical rejection is suspected.

Eleven patients after liver transplantation underwent 17 radiological interventions. Most of the cases were encapsulated fluid collections with episodes of fever. Radiological interventions make re-operations unnecessary in the majority of the cases. Our data are compared with those of other publications.