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Biomedical subjects

M Lenz

Publications and source records attributed to M Lenz.

At least 109 records · Page 6Linked to original sources
PubMed1986

Temporal bone region: high-resolution MR imaging using surface coils.

Specially designed surface coils for the region of the temporal bone enable high-resolution magnetic resonance (MR) imaging of the structures of the inner ear. Eight healthy volunteers and 21 patients (six with cholesteatomas, five with acoustic neuromas, five with glomus tumors, and five with mastoiditis) were examined using a 0.5-T MR imager. The demarcation of tumor extent with MR imaging was better than with computed tomography because of improved soft-tissue contrast and because the surrounding bony tissue did not generate any signal. High-resolution MR imaging is particularly useful for small acoustic neuromas because of its higher specificity compared with gas cisternography.

Brain Neoplasms↗
PubMed1985

[Nuclear spin tomography of the petrous bone and cerebellopontiLe angle. Methods and normal anatomy].

Proton nuclear resonance tomography, also called magnetic resonance imaging, is a new imaging procedure which makes it possible to obtain tomographic cuts of the petrous bone in three planes. It is complementary to CT and is able to demonstrate the small structures of the inner ear and of the cerebello-pontine angle, without bone artefacts and without overlap or distortion. By using special surface coils combined with thin sections and a gradient-zoom technique, it is possible to obtain high resolution images which equal those of modern CT. By choosing suitable exposure parameters and a multi-echo technique, one can obtain excellent tissue contrast without using positive or negative contrast media.

Cerebellopontine Angle↗
PubMed1985

[Nuclear spin tomography of the male pelvis. Methods, anatomy and initial clinical results].

A pilot study of MRI was carried out on three normal male volunteers and 15 patients with tumours in the prostate or bladder. One advantage of the method is the ability to obtain images in three planes, without moving the patient. It is therefore possible for the first time to demonstrate lesions in the base of the bladder in their cranio-caudal extent. Tissue contrast of MRI, using long sequences with suitable proton or T2-weighted images is better than with CT and provides more accurate diagnosis. Even non-expansive tumours within the gland can be differentiated from normal glandular tissue. It has been noted that carcinoma of the prostate in the T2-mode provides an increased signal, whereas tumours of the bladder look dark. Up to a point, tissue characterisation may be possible.

Aged↗
PubMed1985

[Proton spin tomography in diseases in the petrous bone region].

Magnetic resonance tomography (MRI = magnetic resonance imaging) can provide sectional images of the petrous bones in all planes. It is complementary to computed tomography (CT) and can demonstrate inflammatory changes in the petrous bones and mastoids, and cholesteatomas, with accuracy and without artifacts. MRI is inferior to CT for the demonstration of bone destruction and this this limits its use in the diagnosis of glomus tumours. The use of special surface coils combined with thin sections and a gradient-zoom technique provides high resolution images which approach the quality of modern CT examinations. This opens new possibilities for the diagnosis of small acoustic neuromas; because of the excellent tissue contrast, they can be well demonstrated without using intravenous contrast media or intrathecal air (CT-air meatography).

Adult↗
PubMed1984

[Prevention, clinical aspects and therapy of the side-effects of lidocaine].

In 134 patients with an acute myocardial infarction a prolonged lidocaine infusion was performed. In 6.7% of the patients severe side effects occurred. They appeared with central-nervous and haemodynamic symptomatology. In 6 patients with a high degree of severity of the side effect a determination of the plasma content could be performed, which in every case showed contents during the process above the therapeutic region. It was confirmed that side effects of lidocaine are to be apprehended, when the therapeutic region (2-6 mg/l-1) of the antiarrhythmic drugs is transgressed. On the basis of own experiences and reports from literature the therapeutic approach in lidocaine side effects is concerned and possibilities are shown to avoid them.

Arrhythmias, Cardiac↗
PubMed1984

[Arteriographic diagnosis of erectile impotence].

The complex interactions of psychological, neurological, hormonal and vascular aspects of erectile dysfunctions require a standardised multidisciplinary diagnostic evaluation. The recent establishment of new noninvasive and invasive investigative procedures has led to a fundamental change in the assessment of erectile dysfunctions. Selective angiography of the internal pudendal artery and its branches represents the crucial diagnostic step before treatment can start. Indication, technique and results of 26 bilaterally performed pudendal angiographies on impotent patients are described.

Adult↗
PubMed1984

[Selective embolization of the internal iliac artery in life-threatening hemorrhaging prostatic cancer].

The catheter embolization of the a. iliaca interna is a quick, little straining and effective method in order to control bleedings threatening life in the region of the organs of the small pelvis. It is superior to surgical ligature because of the better result and the less straining intervention. With the illustration of a case report the method will be demonstrated again and indications and complications will be discussed.

Adenocarcinoma↗
PubMed1984

[Nuclear spin tomographic study of the facial skeleton. I. Nuclear spin and computed tomographic anatomy].

The resolution of NMR and CT was compared using axial sections of the normal anatomic structures of the facial skeleton. It was shown that NMR was superior in differentiating muscles, tonsils, mucosa, lymph nodes and blood vessels. The demonstration of bone and its differentiation from air-containing spaces is often difficult. Metallic, non-ferromagnetic dental fillings, which cause serious artefacts on CT, do not affect NMR.

Adult↗
PubMed1984

Percutaneous sclerotherapy of varicoceles--an alternative to conventional surgical methods.

Between May 1981 and October 1982, 259 varicoceles were identified by phlebography. It was possible to occlude 217 with Varicocid using a percutaneous Seldinger catheterisation technique under local anaesthesia. This method is an alternative to standard surgical techniques and has several advantages. It is cheap, it can be carried out on an out-patient basis, it lacks the risks associated with general anaesthesia and there are few complications.

Adult↗
PubMed1984

[Value of computer tomography in the detection of regional lymph node metastases, of malignant tumors in the area of the head and neck].

CT is very suitable for showing cervical lymphatic spread in malignant tumors of the head and neck. The regional lymph-node areas of 123 patients with histologically proven malignant tumours of the oral cavity, hypopharynx and larynx were evaluated in a prospective study. Clinical examination, CT-findings and pathological work up of the surgical specimens were comparatively analysed in 53 patients. The proportion of false negative lymph-nodes on palpation was 21%. This error could be reduced by the use of CT to 7.5%.

Carcinoma↗
PubMed1983

[Case report of a choroidal osteoma].

Choroidal osteoma caused blurred vision in a 45-year-old man. Ophthalmoscopy showed a characteristic tumor with irregular elevation and of a yellowish color with a vascular network on the surface. Ultrasonic A-scan findings, hyperfluorescence in angiograms and visibility on computer tomograms confirmed the diagnosis, even though the patient's age and sex, and the location of the tumor, were unusual.

Choroid Neoplasms↗