Biomedical subjects
Publications and source records attributed to P Amundsen.
An acute traumatic epidural hematoma extending from the odontoid process to the dorsum sella is described. The mechanism for the formation of an extradural hematoma in this unusual location seems to be related to age and a severe hyperflexion injury.
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The interpretation of cervical metrizamide myelography requires specific anatomic considerations, particularly when the lateral C1-2 puncture technique is employed. Fresh unfixed cervical spine specimens were injected with a mixture of metrizamide and methylene blue. Radiologic examinations of these specimens were compared with a retrospective analysis of 100 consecutive unselected cervical myelograms obtained by lateral C1-2 puncture during the years 1979-1980. Epidural, subdural, subpial, dentate ligament, and spinal cord injections may be encountered when the lateral C1-2 puncture for myelography is employed; possible artifacts from such injection are discussed.
An open multicentre clinical trial with the new non-ionic contrast medium iohexol is reported. A total of 38 adult patients were included in the series. No serious side effects or complications occurred. The impression was that subjective reactions were less marked with iohexol than what is usually observed with conventional ionic contrast media.
The excretion of metrizamide through the kidneys and intestinal tract was determined in 10 patients submitted to myelography because of sciatica, for a period of 7 days following the examination. In the faeces, less than 5 per cent of the injected contrast medium was recovered during this period. Total recovery in the urine varied considerably from patient to patient, but most of the contrast medium was excreted during the first 48 hours. From the fourth day on, only small amounts were excreted, but even on the 7th day 3 to 11 mg iodine remained, which corresponds to 6 to 22 mg of metrizamide.
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Amipaque 280 mg I/ml was compared to Isopaque Cerebral 280 mg I/ml for common carotid injection in twenty patients in a double blind trial. Simple comparison was also performed in examinations with selective external carotid injections. The reaction of the patients to the common carotid injection was mild on the whole but Amipaque caused significantly less discomfort than Isopaque. Selective external carotid injection of Amipaque caused very little discomfort while most patients complained of severe pain when Isopaque was used. No serious side-effect was observed.
The CT characteristics were studied in a series of 90 tumours, and the diagnostic criteria were determined for meningiomas glioblastomas, other gliomas and metastases. These criteria were then employed in another group of 46 tumours in which the histological diagnosis was not known at the time of examination. The over-all diagnostic accuracy was 85%, and it was largely the same for the various sub-groups. Careful combination of the CT characteristics, perfect techniques, and increased experience may further improve the diagnostic accuracy.
The total number of patients examined with metrizamide (Amipaque) for cervical myelography up to 31 December 1976, exceeds 2,000. Review of this series under more detailed analysis of the 365 examinations performed at the Ullevål Sykehus indicate that such examinations can be performed safely and with excellent diagnostic results, provided the technique is satisfactory. Various techniques may be adequate. The injection of the contrast medium via a lateral C1-C2 puncture with the patient prone ensures optimum control of the contrast column to avoid intracranial flow, and therefore to give the lowest rate of side effects.
A survey is made of the development of water-soluble contrast media and of the experimental and preliminary clinical investigations of the new water-soluble contrast medium metrizamide. The experiences with the medium indicate that its use in the subarachnoid space is safe and reliable.
Two cases of pontine vascular malformation with a characteristic venous angiographic appearance are reported. Both patients had a slowly progressive clinical course, normal spinal fluid, and evidence of a pontine mass. In the late venous phase, large abnormal vessels were seen to coverage towards the midline from each cerebellar hemisphere. The abnormal vessels were microscopically identified as teleangiectases in one of the cases. Both cases had pontine hematomas, originating from a cavernous angioma in one of them; in the other the exact origin of the bleeding could not be determined. It is concluded that in cases with a progressive pontine syndrome the characteristic appearance of the venous phase of angiography may indicate a bleeding pontine vascular malformation.
Six hundred lumbar radiculographies were performed with metrizamide in 581 patients. Excellent radiographs were obtained in almost all cases. The adverse effects were minor and no serious complications occurred. The authors consider metrizamide superior to other water-soluble contrast media in present use from both toxicological and radiological points of view.
One hundred cervical and thoracic myelographies were performed with the non-ionic, water-soluble contrast medium metrizamide. Good myelograms were obtained in almost all cases, adverse effects were minor, no serious complications occurred, and no convulsions were seen. Metrizamide is better than gas or isophendylate for demonstrating intraspinal expansive lesions of affections of the root sleeves.
Angiographic abnormalities of the lower hindbrain seen in 13 cases of Chiari Type I and Type II malformations are described. Previously reported findings are assessed, particularly deformities of the posterior inferior cerebellar artery (PICA). Caudal displacement of the cerebellar tonsils without other angiographic localizing signs of an expanding intracranial mass suggest a Chiari malformation. In such cases it is helpful to demonstrate a low cephalic loop of the PICA, reflecting caudal displacement of the fourth ventricle. Associated angiographic demonstration of significant intraspinal localization of the brainstem is pathognomonic of Chiari malformation.
Seventeen ventriculograms with the non-ionic water-soluble contrast medium, metrizamide, were performed in 15 patients, with neglibible adverse effects. Visualization of the ventricular system was good in most of the patients. A combined technique, using both metrizamide and gas, increased the diagnostic value of the procedure in some cases.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.