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Biomedical subjects

G Friedmann

Publications and source records attributed to G Friedmann.

At least 55 records · Page 3Linked to original sources
PubMed1986

Use of surface coils in magnetic resonance imaging of orbit and knee.

Surface coils are specially designed radio-frequency receiver coils used for magnetic resonance imaging (MRI) of special anatomical regions, for instance, orbit and knee joint, with a higher spatial resolution than that obtained with conventional MRI techniques. They are designed to fit the anatomical part to be imaged, thus enabling a coil to be placed in close proximity to relevant structures. Surface coils can take these different shapes because they are only used for detecting the MR signal and thus do not need to meet particular design specifications for optimal radio-frequency homogeneity. We report our clinical experience with nearly 100 patients in the first year in the special surface-coil approach of orbit and knee joint.

Cranial Nerve Neoplasms↗
PubMed1985

[MR of the knee joint. Imaging of the normal anatomy and pathological findings using surface coils].

A special surface coil was developed with the intention of producing optimal resolution and signal-to-noise ratio for the examination of the knee joint by MRI. Eight volunteers and 25 patients with various abnormalities of the knee have been examined. Normal anatomical structures can be differentiated and there is high diagnostic reliability for lesions of the meniscus, as confirmed by arthroscopy and surgery. Cartilage lesions are less well demonstrated. Total rupture of cruciate ligaments is clearly shown, but partial rupture can often be recognised on the basis of indirect signs only. Good diagnostic results were obtained in cases of osteochondritis dissecans and chondropathia of the patella.

Adolescent↗
PubMed1985

Indications for intravenous and intraarterial digital subtraction angiography (DSA) in the diagnosis of cerebrovascular insufficiency. A new diagnostic concept including ultrasound.

For screening of arteriosclerotic lesions of the carotid bifurcation duplex scanning (B-mode imaging plus doppler flow analysis) is the method of first choice, because it is really noninvasive and offers the same results as intravenous DSA (IV DSA). IV DSA should not be performed as a screening procedure unless ultrasound examinations are not available or are inadequate. Except for patients with isolated unilateral stenosis of the internal carotid artery near the bifurcation confirmed with both duplex scanning and IV DSA, arteriography is required for therapy planning. Aortic arch angiogram, selective extra- and intracranial carotid arteriography and--if necessary--vertebral and subclavian arteriography can be performed with intraarterial DSA (IA DSA). The application of DSA to catheter arteriography will help to reduce further the potential risk of adverse reactions related to high intravasal contrast doses specially in the cerebral circulation, but will not turn arteriography into a risk-free procedure. Postoperative examinations of the carotid bifurcation can be performed with ultrasound as well as with IV DSA. Extracranial bypasses are best demonstrated with IV DSA. Extraintracranial bypasses can be demonstrated only with IA DSA.

Angiography↗
PubMed1985

[Diagnostic problems in recurrences of lymphogranulomatosis].

Report on the incidence of recurrences, the time necessary for complete remission, and the sites of recurrences in 333 patients with demonstrated lymphogranulomatosis. Suggestion of an examination scheme considering clinical data and laboratory findings for early diagnosis of recurrences. Among the image-producing methods, sonography and CT are of special importance besides thorax examination, lymphography, and bone scintigraphy.

Adult↗
PubMed1984

[Sonographic diagnosis of peritoneal carcinosis].

Based on the sonographic findings in 107 cases with proven peritoneal carcinomatosis (PCA) by either gynaecological or gastrointestinal tumors the diagnostic value of ultrasonography and its limitations in differentiation of peritoneal fluid accumulations and masses are presented.

Adult↗
PubMed1984

[Meaningful application of imaging technics in acute appendicitis].

Acute appendicitis is primarily not a radiologically established diagnosis. In atypical abdominal symptoms plain radiographs and additive real-time ultrasonography may often show typical findings especially in complications of acute appendicitis (perforation, abscess formation and ileus). In these cases the differential diagnosis is narrowed and further therapeutic steps may be modified considerably.

Abscess↗
PubMed1984

[Localization of cerebrospinal fluid fistulas with CT cisternography].

Positive CT cisternography has proved a useful method for the accurate pre-operative localisation of liquor fistulae from the skull base. In this way, planning of surgery can be improved with respect to the operative approach and the area to be covered. The risk of a recurrence is also reduced. It is necessary, however, to have a clinically recognisable leak at the time of the examination, since it is otherwise difficult to indicate the flow during the examination. We regard persistent or recurrent liquorrhoea as an indication for this examination, irrespective of its cause, provided it is intended to proceed to surgery after a positive finding. The method has few complications, is easy to perform and, in case of recurrence, can be repeated.

Adult↗
PubMed1984

[Aortic arch angiography in the preoperative diagnosis of cerebrovascular diseases. Comparison of the conventional technic and intra-arterial DSA].

Demonstration of the aortic arch is necessary in the investigation of cerebrovascular insufficiency for showing the origins and course of the cerebral arteries and for detecting steal syndromes and anatomical variations. Intra-arterial DSA is comparable in this respect with the traditional film technique; it has the advantage of reducing contrast doses by 75% and of reducing film costs and the examination time. Reliable evaluation of the carotid bifurcations is possible in less than half the cases. Selective carotid angiography cannot be replaced, therefore, by this technique. Selective angiography is also necessary for the pre-operative study of the intracranial vessels.

Aorta, Thoracic↗
PubMed1984

[Fibromuscular dysplasia of the internal carotid artery].

Various types of fibromuscular dysplasia of the extracranial portion of the internal carotid artery are described; morphologically, the common group shows abnormality of the media. The distribution, with sparing of the carotid bifurcation and of the artery in the carotid canal, as well as the sex and age of the patient, are typical. Possible treatment is discussed.

Adult↗
PubMed1984

[Initial findings with magnetic resonance tomography of mediastinal and hilar tumors].

Twenty-six tumours of the mediastinum and hilar regions were examined by magnetic resonance; the technique and initial experience in distinguishing normal from pathological appearances are described. ECG triggering has proved essential, whereas respiratory triggering was found to be unnecessary. Spin-echo images were found to be best for tumour delineation but, for further characterisation, the inversion recovery mode and multi-echo technique were most satisfactory. In general, the space-occupying lesion was seen as well as it would be with CT. The advantages of the new method are the excellent differentiation of vascular structures and the ability to image in multiple planes, whereas CT possesses better resolution which, in some cases, may be of diagnostic advantage.

Adult↗
PubMed1984

[Morphology of atypical and metastatic pheochromocytoma in computed tomography].

14 cases of pheochromocytoma were investigated by CT including two of them in full detail. The morphology of pheochromocytoma and the changing CT picture with increasing tumor size are discussed. Diagnostic procedure and usefulness of CT as well as differential diagnosis of adrenal tumors are pointed out. Adrenal and extra-adrenal localization of pheochromocytoma and signs of their malignant degeneration are demonstrated.

Adolescent↗
PubMed1983

[Limits of differentiation of focal splenic lesions by sonography and computed tomography].

Based on the results of sonographic and CT-findings in 192 patients the advantages and disadvantages of ultrasonography and CT in the diagnosis of splenic lesions are presented with particular emphasis on anatomy and topography. The relatively uniform presentation of various focal lesions in ultrasonography and CT is demonstrated and the limits of differentiation are discussed. The importance of angiography and scintigraphy is also mentioned.

Abscess↗
PubMed1983

[Indications for intra-arterial digital subtraction angiography (DSA) in vascular disease].

Digital subtraction angiography (DSA), using a direct arterial route, diminishes the risk of the examination by reducing the contrast dose by about 75%, making the examination more rapid and making it less likely that catheters will have to be changed. At the same time superimposition is avoided, one of the advantages of selective catheterisation. In view of the low contrast dose, it is possible to carry out several examinations at one time and to use additional projections for intracranial and peripheral disease, thereby improving the diagnostic value of the examination. For certain problems, intra-arterial DSA is already able to replace conventional angiography. The small field size and poor spatial resolution still make conventional angiography necessary as the basic form of investigation in most other circumstances.

Angiography↗