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Biomedical subjects

W Dewes

Publications and source records attributed to W Dewes.

At least 37 records · Page 2Linked to original sources
PubMed1989

[NMR tomography of the brain in patients on long-term dialysis].

24 patients on long-term dialysis, aged between 20 and 78 years, were examined by brain MRT and CT. Both methods showed equally atrophic changes in the brain; in particular, cortical atrophy appears to increase with increasing duration of dialysis. MRT shows small hyperintensive areas in the white matter which cannot be seen on CT. Hypointensive areas on MRT are not due to calcification, but pathological deposition of metals, such as iron, must be considered.

Adult↗
PubMed1989

[Relaxation time measurements in the differential magnetic resonance tomographic diagnosis of liver tumors].

T1-weighted IR sequences and T2-weighted SE sequences and combined SE/IR sequences were carried out in 62 patients with malignant and 50 patients with benign liver tumours and the T1 and T2 relaxation times were measured. IR sequences proved the most sensitive method for imaging focal liver lesions and providing good contrast between liver tissue and tumour. For lesions above 1.5 cm, quantitative MRI achieved an accuracy better than 95% in distinguishing between haemangiomas and malignant lesions. Routine quantitative measurements of relaxation times were sufficiently reproducible for clinical use.

Carcinoma, Hepatocellular↗
PubMed1989

[Bone marrow scintigraphy and magnetic resonance tomography in plasmacytoma].

In 17 patients suffering from plasmocytoma bone marrow scintigraphy (BMS), and magnetic resonance tomography (MRT) was performed. RES expansion in the extremities was found by both methods, MRT also visualized a diffuse infiltration of the marrow. In that location, cold lesions in BMS correspond to yellow marrow. In the pelvis, however, cold lesions are due to tumor involvement. Both methods offer additional diagnostic opportunities and may in the future allow to expand the time intervals between routinely performed iliac crest biopsies.

Aged↗
PubMed1988

[MR tomography of non-tumor diseases of the brain and cervical cord].

118 examinations were carried out for non-tumorous diseases of the brain and cervical cord. The sensitivity of MRT was analysed and compared with 77 cases where CT had been performed or with sonography in children. MRT showed an abnormality in 80%, whereas CT or sonography lead to a diagnosis in only 43%. Because of the significantly higher sensitivity of MRT, this should be the primary means of examination for this type of case.

Acquired Immunodeficiency Syndrome↗
PubMed1988

[MR tomography of the temporomandibular joint using T1-weighted multislice-gradient echo-sequences].

31 examinations of temporo-mandibular joints, using T1-weighted multislice gradient echo sequences have been performed. The short scan time of one minute and 50 seconds ensured that there were no movement artefacts in 28 cases. The position of the disc was visible in more than 90% of examinations. Degenerative changes in the cartilage and arthroses of the joint cannot be demonstrated adequately by the rapid sequences.

Adult↗
PubMed1988

[Artifact reduction via motion-compensating gradient shifting in MR tomography].

In 62 patients spinecho or gradientecho sequences compensated for motion were compared with corresponding non-compensated sequences. Compensation during MRT reduces those artifacts which are caused by regular motion. This is particularly effective during examination of the brain stem, spinal canal and the heart. The improved demonstration of the morphology of normal and diseases organs simplifies the analysis of the types of movement.

Brain↗
PubMed1988

[Use of a homomorphic filter in combination with surface coils in MR tomography].

A new method for correcting the signal intensity from surface coil (homomorphic filters) was evaluated in 40 examinations. With this filter it is possible to compensate for signal loss when using surface coils for deep tissues and to avoid excessive signals from the surface. The method does not, however, provide any additional information. Properly used, there were no false positive findings, nor was there any loss of abnormal findings. The use of homomorphic filters is therefore safe and sensible.

Filtration↗
PubMed1988

[Phlebography of the upper extremity--examination technic, indications and results].

Three radiological methods of examination can be used in phlebography of the upper extremity: screening (fluoroscopy) combined with on-target x-ray film examination; sheet film angiography; digital subtraction phlebography (DSP). Phlebography of the veins of the forearm performed preoperatively for selecting suitable veins for a dialysis shunt, should be done by screening with on-target x-ray film takes in several planes. DSP should be given preference if there is suspicion of thrombosis of the shoulder veins and the superior vena cava.

Arm↗
PubMed1987

[Bronchography during flexible bronchoscopy. Indications and results in bronchiectasis].

The radiological imaging of the respiratory tract by bronchography has apparently lost in importance since the introduction of newer imaging methods. Indications for and results of bronchography, performed after bronchoscopy with a flexible bronchoscope under local anesthesia, were analysed in 115 patients. In 68 the bronchography had been performed because of suspected bronchiectasis, in the others because of hemoptysis, cough or infiltration of unclear etiology. In 43% of patients who had undergone bronchography bronchiectasis was indeed found, in 47% there were isolated or additional changes in the bronchial system. In 70% the examination had furthered the diagnosis. The described method of bronchography was not significantly more uncomfortable than flexible bronchoscopy alone. Combined bronchoscopy and bronchography is thus a valuable procedure in the diagnosis of pneumonological abnormalities.

Adolescent↗
PubMed1987

[Magnetic resonance tomography (MRT) of the adrenals].

Thirty-eight MRT examinations were carried out in 35 patients who, between them, had 19 abnormalities in the adrenal glands. These included ten adenomas, three metastases, two carcinomas, two phaeochromocytomas, and two primary retroperitoneal tumours. MRT provides images of normal and abnormal adrenal glands which are equivalent to those of CT, with the exception that it cannot demonstrate calcification. Using a ratio of signal intensity from the adrenal tumours and the liver on T2-weighted images, it is usually possible to differentiate adenomas from metastases, carcinomas or phaeochromocytomas. The increased specificity of MRT is valuable in the investigation of patients with asymptomatic enlargement of the adrenal glands.

Adrenal Gland Neoplasms↗
PubMed1987

[Diagnosis of sarcoidosis using MR tomography].

One hundred and thirty-three patients with lymph node enlargement from various causes were examined by MR tomography, using 0.5 and 1.5 Tesla. Amongst these, there were 27 patients with chronically enlarged lymph nodes and histologically confirmed sarcoidosis; these showed characteristic T1 intervals. Enlarged lymph nodes due to chronic inflammatory conditions can be differentiated from lymph nodes with malignant lymphoma, or from lymph node metastases from carcinomas. Although there are problems with the determination of relaxation times on MR tomography, this may be a valuable method for the differential diagnosis of sarcoid.

Adult↗
PubMed1987

[Lung parenchymatous changes following mustard gas poisoning].

The authors present a late sequel of poisoning with dichlorodiethyl sulphide, also known as mustard gas or Ypérite, in a patient of 22 years of age--a late sequel not described in the literature to date. After the poisoning, a severe pulmonary fibrosis with pulmonary artery hypertension developed. A mediastinal emphysema that had so far been observed only during the acute intoxication phase, was evident even two years after the intoxication. Perivascular collections of air in the left lung communicating via the left hilus with the mediastinal air point to the existence of bronchus or lung parenchyma fistulas.

Adult↗
PubMed1987

[MR tomography of Kallmann's syndrome].

MR tomography is the only imaging method that can demonstrate atrophy of the olfactory lobe of the brain in olfacto-genital dysplasia (Kallmann's syndrome). The MRT findings in five patients with Kallmann's syndrome are described. The MRT criterion for the presence of Kallmann's syndrome appears to be an interruption or total absence of the olfactory sulcus.

Adult↗
PubMed1987

[MR tomography in the control of chemonucleolytic therapy].

MR tomography can be used for the diagnosis of lumbar disc prolapse and provide information concerning the indications and the follow-up of injection treatment with chymopapain. It is able to distinguish various parts of the disc from their varying signal intensity. Examination of 26 patients showed the effect of chymopapain on intradiscal fluid shift based on shifts in signal intensity. The use of T2-weighted gradient echo sequences over a period of seven to ten minutes is sufficient to show significant changes in the disc following chemonucleolysis.

Female↗
PubMed1987

[MR tomography in lymphatic and leukemic bone marrow infiltrations. A comparison with scintigraphy and conventional x-ray diagnosis].

MR is the only noninvasive procedure that can demonstrate changes in the medullary space. If it is combined with bone marrow scintigraphy and conventional x-ray film diagnostics, it can yield a comprehensive diagnosis of bone marrow infiltrations in the regions of the pelvis, thighs and lumbar vertebral column in leukaemia or malignant lymphomas. The T1 relaxation times of the malignant infiltrations are enhanced compared with normal fatty marrow. MR tomography of the bone marrow is particularly suitable for determining the therapy or follow-up control of a malignant systemic disease.

Bone Marrow↗