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Biomedical subjects

J Lissner

Publications and source records attributed to J Lissner.

At least 73 records · Page 4Linked to original sources
PubMed1987

[Contrast enhancement of the nipple in nuclear magnetic resonance tomography of the breast with Gd-DTPA].

Contrast enhancement around the nipple has been evaluated retrospectively in 51 of 70 patients in respect of the underlying breast disease. 2 of the patients had to be considered separately because of malignant disease of the nipple or areola itself. The remaining 49 patients showed no close relation between the underlying breast disease and the amount of contrast enhancement in the nipple. This phenomenon of a non-pathological significant contrast enhancement of the nipple appears important to avoid false positive diagnoses in MRI of the breast with Gd-DTPA.

Breast↗
PubMed1987

[Radioimmunoscintigraphy with monoclonal antibodies].

Radioimmunoscintigraphy is presented as a new imaging modality in nuclear medicine, using specific antigen-antibody interactions. Monoclonal antibodies to tumor-associated antigens facilitate the characterization of molecular differences between tumors and normal cells. Labelled with gamma-emitting radioisotopes like I-131, I-123, In-111, and Tc99M, these antibodies can be used for in-vivo imaging. Radioimmunoscintigraphy does not compete with morphological modalities like CT and ultrasound, but provides additional information based on its functional principle. Hidden lesions may be detected. Target-to-background ratios, however, are still rather low hampering scintigraphic imaging. The use of Single Photon Emissions Computed Tomography (SPECT) in addition to planar scintigraphy resolves background activities thus providing better visualization and localization of tumors, and increasing sensitivity. The high cost of these time-consuming studies is still a limiting factor to its wider use. Its preliminary indication is founded on the suspicion of tumor progression, based on clinical findings and/or increasing serum tumor markers (CEA, CA 19-9, CA 12-5). This paper provides an overview over possible applications of radioimmunoscintigraphy. Its clinical use is demonstrated by studies of malignant melanoma, colorectal cancer and ovarian cancer.

Antibodies, Monoclonal↗
PubMed1987

[Imaging of the Achilles tendon using magnetic resonance tomography].

The Achilles tendon and pre-achillean space of 30 patients was studied by MRI. A surface coil (Helmholtz' principle) was applied and all patients were examined with a superconducting magnet operating at 1.0 Tesla field strength. The purpose of the study was to illustrate pathological changes of the tendon and the surrounding soft tissue. In 3 cases MRI diagnosed a total rupture of the Achilles tendon. Furthermore, the strain of the tendon and side effects of an inflammatory process could be demonstrated. The use of a surface coil yields a high resolution of the normal anatomy of the region and of the pathological changes of the tendon and the surrounding soft tissue structures. The advantages of MRI for Achilles tendon diagnostics against competitive modalities are excellent soft tissue contrast, multiplanar imaging, as well as exact delineation and visualisation of the lesion.

Achilles Tendon↗
PubMed1986

[Effect of types of field used in nuclear magnetic resonance tomography on core and surface temperature in the human body. Results of in vitro and in vivo experiments].

Deep and superficial body temperature was measured by in vitro and in vivo experiments, using a fluoro-optic procedure and a variety of magnetic and electromagnetic fields in the course of magnetic resonance tomography. The in vitro experiments had shown that measured temperature changes resulting from a static magnetic field were reversible and could be reproduced readily. Temperature measurements in the human body were carried out centrally (oesophageal and rectal measurements) and at the periphery (intravascular). In vivo experiments on 30 experimental subjects showed no significant changes (p = 0.05) in central or surface temperatures as a result of static or dynamic magnetic fields or electromagnetic high frequency fields.

Body Temperature↗
PubMed1986

[Use of Gd-DTPA in the nuclear magnetic resonance study of the breast].

55 patients with altogether 60 breast masses have been examined postoperatively by plain MR, MR with Gd-DTPA and mammography at our institution. All breast carcinomas and fibroadenomas did enhance significantly. Non-proliferative dysplasia, normal breast tissue and scar tissue did not enhance significantly. Borderline enhancement has been found in cases of proliferative dysplasia. The diagnostic accuracy has been improved by MR with Gd-DTPA. Advantages have been an improved visualization of tumors in dense breasts, an improved differentiation between irregular dysplasia and carcinoma and an improved differentiation between post-therapeutic changes (after radiation, surgery or silicon implants) and carcinoma. Nevertheless both technical improvements and further clinical experience is necessary.

Breast↗
PubMed1986

[Magnetic resonance tomography in suspected acoustic neurinoma: technic and differential diagnosis].

Sixty-five patients with suspected acoustic neuromas were examined by CT and MR; the optimal diagnostic procedures are discussed. Extrameatal acoustic neuromas (11 cases) were all diagnosed by CT and MR, but only 82% of intrameatal tumours could be diagnosed by CT combined with air cisternography. Using special surface coils and the paramagnetic contrast medium Gd-DTPA, the accuracy of MR was 100%. All tumours greater than 4 mm were demonstrated. Following clinical and neurological examination, MR is the primary diagnostic method in the investigation of acoustic neuromas.

Diagnosis, Differential↗
PubMed1986

Magnetic resonance imaging compared with computed tomography and myelography in the diagnosis of spinal masses.

Magnetic resonance imaging (MRI) is superior to computed tomography (CT) and myelography in the demonstration and delineation of the extent of syringomyelia. In the detection of intramedullary tumors MRI is more sensitive than CT and myelography. MRI provides additional information on the sagittal and frontal planes regarding the extent of tumors. In the diagnosis of disc prolapse MRI seems to be as accurate as CT or myelography. Additional information is available with MRI in the diagnosis of degenerated disc tissue. Spinal stenosis is easily recognizable. CT was superior in the differentiation of bony and disc protrusion. The results show that MR has opened up new possibilities in the diagnosis of spinal diseases and will lead to a reorientation of the diagnostic approach.

Diagnosis, Differential↗
PubMed1986

[Computed tomography in endocrine orbitopathy: the effects of varying gantry tilt and patient positioning on the measurement of eye muscle thickness and the possibilities for correction].

Thickening of eye muscles in endocrine orbitopathy can be demonstrated particularly impressively in coronary computed tomograms. However, when measuring the height and width of rectus eye muscles manifesting pathologic changes, the measurement is increased by a deviation from the coronary section plane; this is due to different tilting of the gantry. This often leads to an incorrect stage classification and makes objective observation of the course (e.g., under therapy) impossible. By converting the measured values into the actual extent of the muscles by means of the cosine set, appreciable changes in the pattern and frequency of affection of the rectus eye muscles were found in 121 patients examined.

Adult↗
PubMed1986

[Two-year clinical experience with Mevamatic 3--development of a verification and protocol system for irradiation units].

Since 1983 the computerized record and verify system Mevamatic 3 was tested in connection with the linear accelerator Mevatron 77 (Siemens Company). In consequence of the software development the handling of the system was improved for the clinical routine with the result of a fully utilizable system. The topics of this report are the description of the hardware, the functions of the system, the software development and some possibilities for improvements in the future.

Germany, West↗
PubMed1986

[Radiotherapy of seminoma: small-volume irradiation at the stage pT1N0M0--prophylactic irradiation of the mediastinum].

122 patients suffering from seminoma were irradiated between 1971 and 1981 at the Radiotherapy Department of the University of Munich. 113 patients were available for retrospective analysis. The ten year actuarial survival for all patients was 93%. The survival rate in stage pT1N0M0 (UICC classification) was 100%, in stage pT2-4-xN0M0 97%, in stage pT1-4-xN1-3M0 93%, and in stage pT1-xN4M0/pT1-xN1-4M1 69%. Using a stage adapted target volume, the exclusive irradiation of the paraaortic nodes in the stage pT1N0M0 led to a cure-rate of 100%. Because of this result, and due to the improved tolerance and lower exposure to the remaining testis we recommend this method. The effectiveness of radiotherapy, also in advanced seminomas, the benefit of prophylactic mediastinal irradiation and the therapeutic modalities for treatment of extragonadal seminomas are discussed.

Cobalt Radioisotopes↗
PubMed1985

Constrictive pericardial disease: prognostic significance of a nonvisualized left ventricular wall.

Twenty-six patients with pericardial constriction confirmed by catheterization were studied by dynamic computed tomography (CT). The posterolateral wall of the left ventricular myocardium was not detected in five patients (19.2%). None had evidence of previous myocardial infarction on electrocardiogram or levocardiogram. In 16 patients, a pericardiectomy was performed to remove pericardial constriction. All five patients with nondetectable posterolateral walls of the left ventricle died at or immediately following surgery because of acute myocardial failure. Nonvisualization of the posterolateral wall of the left ventricle in patients with constrictive pericarditis suggests the presence of myocardial fibrosis or atrophy. Surgery is an extremely high risk in these patients.

Adult↗
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

[Nuclear magnetic resonance tomography in breast cancer diagnosis--present status and future outlook].

Due to its high soft tissue contrast MR appears particularly well suited for the examination of the breast. However, it was only after the development of breast coils and the concomitant improvement of the image quality that examinations regarding the potentials of MR in breast cancer diagnosis became interesting. Thus, MR of the breast is still in the initial stage. First results indicate that at present the expected tissue differentiation by MR parameters T1, T2 ...) is not possible MR proved nevertheless advantageous for selected cases. Further research is necessary.

Breast Neoplasms↗
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↗