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Biomedical subjects

M Rath

Publications and source records attributed to M Rath.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Digital radiography--methods and clinical application].

The term "Digital Radiography" covers all x-ray techniques which produce a projected image with the help of digital imaging techniques, which are very similar to a conventional x-ray film image. The advantage of "Digital Radiography" is the possibility of digital image processing, like the subtraction technique, the selective material filtering technique and the quantitative image plotting technique. With the equipments now in use, the digital projected image is produced by the line or on an even level. One example of the in-line projected image is the so-called "topogram", produced via computed tomography equipment. With the help of an x-ray video chain, it is possible to produce digital images on an even level. This technique is used, for example, for "digital video subtraction angiography" (DVSA). Today, digital radiography is clinically used only in the "DVSA" and the "topogram" systems. A survey of the clinical use and the improved future possibilities of digital radiography is given, and the special features of the method are discussed.

Analog-Digital Conversion↗
PubMed1985

[NMR tomography in urology. Principles--technics--risks--areas of use].

NMR tomography is a new imaging method based on nuclear magnetic resonance. It is possible to obtain sectional views of the human body in all three planes without ionizing radiation. NMR can differentiate soft tissue better than CT, and large blood vessels can be simultaneously evaluated without using contrast medium. The pathological process could be imaged exactly in every examination. Due to the lack of image clarity caused by breathing movement, NMR is not superior to CT when using contrast medium in the epigastrium. Calculation of relaxation times T1 and 2 shows clear differences between tumor and normal tissue. However, contrary to initial expectations. NMR did not permit a type-specific diagnosis to be made. Three-dimensional images improve the process of staging tumors, especially in the retroperitoneal space and in the pelvis. As with CT, metastatic lymph nodes can only be demonstrated when they have reached a size of at least 1 cm. Further studies will be necessary to evaluate the validity of this new imaging method.

Contrast Media↗
PubMed1984

[Clinical significance of nuclear magnetic resonance tomography in urology. Initial experiences].

NMR tomography, which is based on nuclear magnetic resonance, enables the production of sectional images of the human body without ionising radiation. In particular, the field of urology places great hopes on this new procedures, since the contrast in soft tissue is considerably better than that of computer tomography. Our first clinical results confirm the advantages of the soft tissue differentiation as well as the possibility to judge the large vessels safely and simultaneously without contrast medium, which is advantageous in the detection of tumours in the retroperitoneum and in the region of the kidneys. An improvement of the preoperative staging of urological tumours can be achieved by means of primary three-dimensional images. Only after several years of experience with NMR tomography and all its variations will it be able to evaluate properly, to what extent clinically relevant diagnostic possibilities are offered by the analysis of relaxation values.

Diagnosis, Differential↗
PubMed1984

[Digital radiography. Equipment technology and initial clinical results of digital angiography with an electronic universal work station].

Using a prototype of an electronic, universal examination unit equipped with a special x-ray TV installation, spotfilm exposures and digital angiographies with high spatial resolution and wide-range contrast could be made in the clinic for the first time. With transvenous contrast medium injection, the clinical results of digital angiography show excellent image quality in the region of the carotids and renal arteries as well as the arteries of the extremities. The electronic series exposures have an image quality almost comparable to the quality obtained with cutfilm changers in conventional angiography. There are certain limitations due to the input field of the 25 cm x-ray image intensifier used. In respect of the digital angiography imaging technique, the electronic universal unit is fully suitable for clinical application.

Angiography↗
PubMed1984

Digital subtraction angiography in the diagnosis of arterial complications after renal transplantation.

Digital subtraction angiography (DSA) was used to study arterial complications following renal transplantation in 33 patients. The results were compared with clinical follow-up and in three cases with conventional angiography. In 9 per cent using DSA (3 cases) we experienced inadequate visualization of the renal arteries of the graft; in 91 per cent, the visualization was diagnostically sufficient. In 53 per cent, we discovered an arterial stenosis of the main artery or segmental artery and in one case an AV-fistula. No morbidity resulted during the procedure. We consider DSA to be the best non-invasive method in the evaluation of patients with suspected renal artery stenosis following kidney transplantation.

Adolescent↗
PubMed1984

[Nuclear magnetic resonance in the Hallervorden-Spatz syndrome].

Two patients (mother and son) with Hallervorden-Spatz's syndrome were examined both via CT and Nuclear Magnetic Resonance (NMR), using different measuring modes. In the patient with progressing disease pathological findings were seen in the right and left putamen with CT and NMR. All examinations in the mother with a less progressive syndrome were without any result. Information obtained via NMR did not yield significantly more relevant data than computed tomography.

Adolescent↗
PubMed1984

[New possibilities of radiologic diagnostic methods for diseases of the spinal column using spinal computer tomography].

During the last there years (from May 1981 to March 1984) we performed 1368 CT examinations of the spine, 447 of the cervical, 264 of the thoracic and 657 of the lumbar vertebral column. 30% of the CT examination of the lumbar spine revealed a prolapse of an intervertebral disk. In 38% of the cases involving the thoracic spine metastases were seen. We diagnosed fractures in 10% of the cervical spine and 11% of the thoracic spine examinations. Posttraumatic or postoperative intravertebral haemorrhage was hardly ever diagnosed in our patients (1.9% of the cases). Spinal trauma: The anterior-posterior and lateral plain films continue to be the mainstay of radiographic screening in spinal injury. Nevertheless, the degree of injury is underestimated in a significant number of patients with spinal trauma if conventional radiography is the only diagnostic approach. For further clarification CT proved to be the fastest and best method to recognise the causes and extent of compression of the vertebral canal. CT has attained a high degree of accuracy in the diagnosis of prolapse of intervertebral disks, replacing myelography if the findings are unequivocally established. CT should also be preferred to myelography in suspected recurrent prolapse. Localisation, shape and density are criteria for differentiating between scarification and prolapse via CT. The results show that CT has opened up new possibilities in the diagnosis of spinal diseases and has resulted in a reorientation of the diagnostic approach.

Humans↗
PubMed1984

[Nuclear magnetic tomography in cervical lymph node swellings].

Magnetic Resonance Imaging (MRI) and CT were performed in a patient suffering from carcinoma of the larynx with swollen cervical lymph nodes. MRI images in coronal planes give new diagnostic information about the spatial extension of pathologic findings and about the question of compression or infiltration of vessels. Exact topographic knowledge will be necessary. A subject of research is the differentiation between scar formation and tumour relapses.

Aged↗
PubMed1983

[Control of reconstructive vascular surgery using digital subtraction angiography (DSA)].

100 patients were evaluated by DSA after vessel reconstructions by surgery or percutaneous transluminal angioplasty (PTA). The visualization of the proved vessels was very good or good in 92%, sufficient in 6% and without diagnostic value in 2%. Patency of grafts and postoperative vascular abnormalities like stenoses, occlusions or aneurysms were well demonstrated. According to our results, DSA is an excellent semi-invasive method with a high accuracy for postoperative evaluation of vascular reconstructions.

Adult↗
PubMed1983

[Digital subtraction phlebography].

The usefulness of digital subtraction angiography of the venous system, which we have termed "digital subtraction phlebography (DSP)" was demonstrated in the region of the vena cava, the pelvic veins and the veins of the arms. DSP is especially of diagnostic value in the region of the vena cava and pelvic veins and offers no advantage in the veins of the lower extremities compared to conventional phlebography. DSP is a time--and cost--saving method, furthermore minor concentrations of contrast media are needed.

Aorta, Thoracic↗
PubMed1983

[Computer tomography evaluation of tumor-induced bladder wall changes].

25 patients in whom a carcinoma of the urinary bladder had been confirmed, were examined preoperatively by means of computerised tomography, and the local size of the tumour was determined. These findings were compared postoperatively with the histopathological staging. The degree of tumour spread was verified exclusively via cystectomy. CT does not yield very relevant data in respect of the therapeutically important differentiation of the low tumour stages. However, CT is very well suited in the diagnosis of tumours which have penetrated the bladder wall; however, diagnostic relevance in respect of organ infiltration can be definitely limited by the overlapping of other organs.

Carcinoma, Transitional Cell↗
PubMed1982

Indication for, and valuation of computed tomography following anterior resection of the rectum.

During a controlled study, 55 patients who had an anterior resection of the rectum were thoroughly examined, including by computed tomography. The results verified the following statements: 1. The use of CT as a screening-method for early detection of local tumour recurrence following anterior resection of the rectum appears not to be justified. 2. CT is indicated: a) if there is a laboratory or clinical suspicion of recurrence, despite normal findings on proctoscopy; b) to clarify the question of extramural extension if recurrence has been established by proctoscopy. 3. Following anterior resection of the rectum, CT normally demonstrates no remarkable development of scar tissue, unless the anastomosis is inadequate. 4. Following anterior rectal resection every indefinable tissue thickening in the pelvis must be considered a possible tumour recurrence and must be further investigated by needle biopsy.

Carcinoma↗