F. C. Crezee

Imaging of brain metastases

SummaryFor the demonstration of brain metastases both CT and MRI are available as diagnostic modalities. To compare both imaging methods as to their sensitivity in detecting brain metastases CT scans and MR images of 60 patients with suspected brain metastases were evaluated. Comparing contrast-enhanced CT and plain MRI neither modality was found to be clearly superior in this respect.

Contrast Enhanced Magnetic Resonance Imaging of the Brain Using Gadolinium-DTPA

This report concerns a clinical trial with gadolinium-DTPA (Gd-DTPA) as an intravenous contrast medium for magnetic resonance imaging (MRI) in patients with disorders of the central nervous system. Fifty patients, 30 females and 20 males, were examined without and with Gd-DTPA. The contrast medium was well tolerated by all patients. The results of MRI scanning without and with Gd-DTPA and those obtained with computed tomography (CT) using intravenous contrast enhancement were compared. This investigation comprised mainly patients with intracranial tumors, multiple sclerosis, and nasopharyngeal tumors. The results may be summarized as follows: 1) MRI with Gd-DTPA (MRI+) gave better results than MRI without Gd as regards delineation of the lesion, blood vessels and edema in cerebral tumors, pituitary adenomas and acute forms of multiple sclerosis (MS). 2) MRI+ was better than CT in 32 of the 50 cases examined; with intracerebral tumors it was better in 15 out of 18 cases. 3) MRI+ was always better than CT in patients with MS. In 3 out of 7 cases MRI demonstrated the acute MS lesions. 4) MRI+ seemed to have advantages also in nasopharyngeal tumors as ascertained from this limited experience.

Iohexol 300 mg I/ml versus Iopamidol 300 mg I/ml for cervical myelography double blind trial

Omnipaque (Iohexol) is the 2nd non-ionic contrast medium developed and marketed by Nycomed AS, Oslo. Experimental studies have shown that the toxicological and pharmacological properties of Omnipaque are closely related to those of Amipaque (Metrizamide) (Lindgren 1985; Bryan et al. 1985). However, when administered intrathecally, Omnipaque has less excitative and depressive effect upon the cerebral nervous system than Amipaque. Iopamidol is another 2nd generation non ionic monomeric contrast agent. It was considered of interest to compare those 2 media in the CNS. The main objective of this phase III trial in cervical myelography was to compare the safety, tolerance and image quality of Iopamidol and Iohexol by monitoring: clinical examinations adverse reactions (with attention to psychological disorders) diagnostic information

Comparison of iohexol 300 mg I/ml and Hexabrix 320 mg I/ml in central angiography

SummaryIohexol 300 mg I/ml and Hexabrix 320 mg I/ml have been compared in a randomized, double blind, parallel study, to evaluate hemodynamic parameters, diagnostic information and adverse reactions. A total of 55 patients entered the study, one of them was later excluded, bacause both contrast media were given by mistake. In the included material, 21 patients were given iohexol 300 mg I/ml in 55 selective injections and 23 patients Hexabrix 320 mg I/ml in 65 selective injections. The median total dose was 52 (12–88) ml in the iohexol group and 51 (13–118) ml in the Hexabrix group. No changes in heart rate were seen. Angiograms of good or excellent quality were obtained, and no difference between the two media was shown. No serious adverse reaction accured, and no statistical significant difference was found between the two media with respect to subjective patient reactions. The results indicate that the non-ionic, low-osmotic contrast medium iohexol is well tolerated in cerebral angiography with respect to the parameters tested. No statistical significant difference was found in any of these parameters between iohexol and Hexabrix.

Ultrasound in follow-up of the postoperative brain

SummaryThe authors report on their early results in the ultrasound (US) follow-up of postoperative brain pathology, both supra-and infratentorial. The use of US is dependent on the presence of an acoustic window in the skull after craniotomy. Five patients were investigated via a suboccipital craniotomy and one patient via a temporal skull defect. In the patients with a suboccipital craniotomy the greatest part of the posterior fossa, the 3rd and lateral ventricle could be made visible. In a patient with a temporal craniotomy the involved parts of the brain were demonstrated satisfactorily. If a skull defect persists after surgery US may be of value in the follow-up of postoperative conditions, such as the assessment of tumour residue or recurrence, hydrocephalus, postoperative complications and response to radio- or chemotherapy.

Comparative Study of MRI Versus CT for the Diagnostic Work up of Lesions in the Nose and Paranasal Sinuses

Staging of malignant tumours of the nasal cavity and paranasal sinuses was studied in a total of 36 patients using Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). Areas affected by the tumour were studied and clinical staging was carried out using CT and MRI separately. For most cases, surgical findings were also available and could be used for comparison. In a number of cases (n=13) in which the lesions were due to benign lesions, the results of MRI and CT were also compared with one another and if possible with surgical findings. The results of CT and MRI were compared by statistical analysis.