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Biomedical subjects

W Jaschke

Publications and source records attributed to W Jaschke.

At least 91 records · Page 5Linked to original sources
PubMed1988

[Angiographic detection of focal changes in the liver].

CT and ultrasound have completely replaced angiography in the diagnosis of focal liver lesions. However, angiography of the liver is still important for delineation of the vascular anatomy and enhancing diagnostic specificity, especially prior to hepatic surgery. CT angiography using water-soluble or oily contrast materials improves the diagnostic accuracy with regard to the number of lesions detected in patients with liver metastases or hepatoma. Both techniques reveal more lesions than do standard angiographic methods.

Adult↗
PubMed1987

Relative carotid blood flow measurements in dogs by high-speed CT. A preliminary study.

A high-speed computed tomography (CT) scanner was used for measuring flow in a phantom and in the common carotid arteries of six dogs. The general ability of the scanner to assess flow using contrast media boluses was tested with the phantom. The validated simple concept was then used in the animals. The carotid blood flow was varied with a distal occluder on one side and measured with electromagnetic flow probes in both vessels. The results are promising and demonstrate a good correlation between the high-speed CT findings and those measured with the flow probes.

Animals↗
PubMed1987

[Gunshot injuries of the skull. Computerized tomography findings and clinical course].

The clinical and computed tomographic findings in 22 civilian cases of craniocerebral gunshot injury are reported. Fifteen out of the 19 male cases were suicidal attempts; the 3 women were shot by their husbands. In 2 cases the injuries resulted from use of a slaughterer's gun. The level of consciousness is a valuable predictor of outcome from the clinical point of view. CT findings such as bihemispheric injury and detection of intraventricular blood or air were associated with a poor outcome. Surgical intervention appears to be justified only in patients with extensive subdural or epidural hematoma. The mortality rate in this study was 45%.

Adolescent↗
PubMed1986

Spatial resolution analysis of computed tomographic images.

Methods are presented for the quantification of spatial resolution in x-ray computed tomographic (CT) images. Model-dependent methods are derived and compared with model independent methods for computation of the Modulation Transfer Function (MTF). These techniques are applied to phantom images of point, line, edge, and ring discontinuities. The model-dependent methods utilize multiparameter fits of a two-dimensional model function to the image data. Model predictions are compared with results obtained in a model-independent way by numerical transformation of the data. Results of resolution measurements of an Imatron C-100 CT scanner at UCSF and a second experimental scanner at the UCSF Physics Research Laboratory are presented.

Humans↗
PubMed1985

Measurement of cardiac output by cine computed tomography.

High-speed computed transmission tomography (cine CT) is a new noninvasive technique that may be useful for the rapid, accurate quantitation of cardiac function. The capability of cine CT to assess cardiac output was examined 10 mongrel dogs as an initial step in validating this method. After the dogs were anesthetized, femoral arterial pressure and pulmonary artery thermodilution catheters were inserted. After intravenous injection of a bolus of contrast medium, cine CT scans were performed in the flow mode, in which 50-ms scans were triggered electrocardiographically at end-diastole at 8 levels during sequential cardiac cycles. Scans and thermodilution measurements of cardiac output were obtained at rest and during altered hemodynamic states induced by separate infusions of dobutamine and phenylephrine. Time-density analysis was performed over the left ventricular cavity and curves were fitted to the CT flow data by gamma-variate analysis. Using the Stewart-Hamilton equation established for indicator dilution techniques, the cardiac output was calculated. The results established a direct linear correlation (r = 0.92) between cine CT cardiac output and thermodilution cardiac output over a wide range of cardiac outputs (1.5 to 6.3 liters/min). This study demonstrates that cine CT can provide a reliable estimate of cardiac output noninvasively using contrast medium as an indicator in dogs.

Cardiac Output↗
PubMed1985

[Scheuthauer-Marie-Sainton syndrome. Differential diagnosis and treatment of clavicular deformity].

The genesis and clinical characteristics of Scheuthauer-Marie-Sainton's syndrome (dysostosis cleido-cranialis), of congenital pseudoarthrosis of the clavicula of post-traumatic clavicular pseudoarthrosis in childhood determine the differential diagnostic considerations of pseudoarthrosis in children in cases which are initially not clear. The therapy is, however, independent of the cause of the disease: Resection of the pseudoarthrotic bone, filling of the defect via a cortico-spongious block and stabilisation via plate osteosynthesis.

Adolescent↗
PubMed1985

Dynamic CT scanning of the normal canine liver: interpretation of time density curves resulting from an intravenous bolus injection of contrast material.

Seven adult male mongrel dogs were monitored by electromagnetic flow probes and string occluders around the hepatic artery and portal vein. Then, time density curves of the liver, aorta and portal vein were recorded using dynamic CT scanning following the bolus injection of contrast material into a peripheral vein (n = 7) and a mesenteric vein branch (n = 5). Information on total hepatic blood flow could not be obtained from the mesenteric vein injection. The hepatic time density curve could, however, be broken into its two components, hepatic arterial and portal venous flow contribution, by selective ligation of the hepatic artery or portal vein. It could be demonstrated that the arterial component of liver enhancement reached its peak at the end of the aortic wash-out of contrast material. Thus, the hepatic time-density curve could be broken in its two components by superimposing the aortic time density curve onto the hepatic curve. An attempt was made to estimate relative portal venous blood flow by using the slopes or the peaks of both components of the hepatic curve. Using the slopes of the hepatic curve resulted in a consistent underestimation of portal venous blood flow, whereas the peaks gave an estimate of portal venous flow with an accuracy within +/- 8%.

Animals↗
PubMed1984

[Achalasia in the neonatal period and early childhood].

Achalasia is a rare unusual lesion of the oesophagus in children under one year of age. The present report describes a boy of 2 months of age suffering from symptoms of oesophageal achalasia and pylorospasmus. Literature is reviewed in order to discuss frequency, pathogenesis and therapy. The infant underwent a successful Heller oesophago-cardio-gastric myotomy completed by fundoplicatio as a reflux barrier.

Esophageal Achalasia↗
PubMed1984

[Imaging of blood flow-dependent curve parameters in the course of sequential computed tomography of the kidneys following intravenous injection of a contrast bolus].

Since the introduction of fast CT scanners with short scanning times the early density changes observed during the first transit of a contrast bolus can be clearly demonstrated and quantified. A theoretical curve can be fit to the CT data describing the density changes in the kidney according to the indicator dilution principle. A curve parameter can be obtained which characterizes the shape of the curve. Then an image can be calculated which reflects the selected curve parameter rather than tissue densities. Such images have been termed "functional images". Using this type of imaging we were able to demonstrate acute changes in renal perfusion.

Animals↗
PubMed1984

[Appropriate management of penetrating thoracic stab injuries].

Knife-stab chest injuries require immediate adequate treatment according to an established pattern. Depending on the clinical findings, the requisite management is performed: Intubation, central vain catheter, tube drainage according to Bülau, thoracotomy. Stabbing weapons should be removed not before admission to a thoracic surgical clinic ready for immediate operation. One of our cases shows that schematic procedure enables adequate "minimal therapy" in spite of dramatic circumstances.

Adolescent↗
PubMed1984

[Lead fracture--a still frequent cardiac pacemaker complication?].

The frequency of pacemaker complications has decreased during later periods of observations. The rate of pacing lead fractures has been reported to amount to 6.2%. According to our experience and data based on 3607 pacemaker implantations for over 15 years this retrospective study examines the following parameters: patient's data, year of implantation, interval till fracture, implantation vena, localisation of the fracture and therapeutic measures. In 1% (36 cases) of our pacemaker patients repeating operations were necessary due to lead fractures. In electrodes implanted after 1977 no break could be observed. Tested material and production methods as well as save implantation modus, avoidance of bending, coiling with a short radius and also a tied fixation ligature, can improve the results.

Adult↗
PubMed1984

[Supine thoracic images with a mobile roentgen unit: comparison between the soft-ray and hard-ray technics].

To compare the influence of kilovoltage on the quality of supine chest roentgenograms obtained with a mobile x-ray unit, we examined the films of 50 patients on whom supine chest radiographs had been taken incidentally within a period of 24 hours both with high and with low-kVp technique. For evaluation of the image quality, a total of 11 criteria were compared and quantitated by 5 observers using a simple score method. The same advantages that have been attributed to the high-kVp technique on upright films were found on the corresponding supine examinations. These films showed a more balanced penetration and greater sharpness than those taken with low-kVp. The wider latitude of the high-kVp technique simplifies the exposure, and fewer repeat takes will therefore be necessary. The diagnostic gain outweights the few disadvantages, which are mostly coupled to the increase in scattered radiation. This, as well as the availability of more powerful and efficient mobile generators, should promote routine application of high-kVp technique for supine chest examinations.

Humans↗