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Notes: Summary Sixty-eight patients with malignant melanoma were examined by CCT and the findings analyzed. Cerebral metastases were detected in 19 patients. Meningiomas were found in three patients, one with neurological symptoms and two without. Typical metastases less than 10 mm in diameter were located superficially in the grey matter, regular, homogenous, hyperdense, with no edema. Extensive peripheral edema was often associated with metastases measuring more than 10 mm. CCT revealed cerebral metastases in 6 (13%) of 46 asymptomatic patients. The metastases measured less than 10 mm in four and less than 20 mm in two of these patients. Scintigraphy was falsly negative in six patients with metastases smaller than 10 mm. Therefore, CCT is the method of choice for screening asymptomatic patients. Angiography may be of value in the differentiation between meningioma and melanoma metastases.

Notes: Summary The MRI examinations of seven patients with acute transverse myelopathy (ATM) were analysed. The patients were examined 2–5 times during the course of their disease with short and long TR/TE spin-echo sequences in the sagittal projection. A previous history of autoimmune disorder and/or signs of infection at the onset of ATM were present in all cases. Cerebrospinal fluid analysis showed local synthesis of immunoglobulin in the nervous system in three cases and signs of infectious myelitis in one. During the acute phase four patients had local enlargement of the cord and all had increased signal on long TR/TE sequences. The outcome was grave in the majority of patients and there seemed to be a correlation between the degree of cord enlargement, persistence of increased signal intensity and limited recovery. Atrophy and remaining high signal intensity were noted on late MRI in patients with poor outcome. In one patient with probable anterior spinal artery occlusion, cavitation of the cord was seen.

Notes: Abstract The radiological findings in six patients fulfilling the criteria of neurofibromatosis type 2 (NF2) were reviewed. Subtle cutaneous lesions were found in three. All patients had bilateral acoustic schwannomas; two had small acoustic tumours and normal hearing. In these patients the presenting symptoms were caused by multiple intracranial meningiomas and spinal neurofibromas, respectively, whereas the remaining four patients presented with hearing loss. Two patients had other cranial nerve tumours. Three patients had rapidly growing multiple intracranial meningiomas; two had multiple spinal neurofibromas and one a spinal meningioma. NF2 is a rare disease with few cutaneous but frequent, typical radiological findings in the central nervous system. The presenting symptom is most commonly hearing loss due to acoustic schwannomas, although symptoms emanating from other intracranial or tumours are not uncommon. The discovery of multiple meningiomas or multiple spinal neurofibromas without cutaneous lesions should initiate a search for acoustic schwannomas even when the patient has normal hearing.

Notes: Abstract Gadodiamide injection, a new nonionic, MRI contrast medium, was compared with the ionic agent gadolinium (Gd)-DTPA at 0.1 mmol/kg body weight in a double-blind, randomised trial in 60 patients, 30 receiving each substance, with known or suspected lesions of the central nervous system. The patients were closely questioned about adverse events. In the Gadodiamide injection group, four patients reported six adverse advents, three of which were judged to be related to the contrast medium. In the Gd-DTPA group, two patients each reported one adverse event, both of which had an uncertain relation to the contrast medium. All events were mild and no medical treatment was needed. No significant change in neurological findings, blood pressure, pulse rate or blood parameters were noted in any patient. Both contrast media were effective; no difference in overall efficacy or safety was observed.

Notes: Summary The commonly used contrast medium metrizoate (isopaque Cerebral®) or the new nonionic iohexol were injected intravenously for enhancement of cranial CT in a randomized double blind study. Each group consisted of 105 patients. No serious reactions occurred. Ten patients receiving metrizoate had minor reactions of mainly allergic type, whereas only one patient receiving iohexol reacted. No differences in enhancement efficiency could be observed.

Notes: Abstract Purpose To compare chemotherapy treatment monitoring in astrocytoma by 201thallium single photon emission computed tomography (SPECT) and photon magnetic resonance spectroscopy (1H-MRS) with magnetic resonance imaging (MRI), and to evaluate the influence of morphological tumor changes on cerebral 201thallium uptake and metabolic changes in 1H-MRS. Materials and methods Six patients with highly malignant astrocytomas were followed with quantitative 201thallium SPECT, MRI, and 1H-MRS during chemotherapy. Maximum follow-up included six examinations per patient by either method during 18 months. Criteria were set for: (1) regression (≥ 25% tumor reduction), (2) status quo (〈 25% reduction and 〈 25% increase), and (3) progression of disease (≥ 25% tumor increase). Results were compared with the clinical state of disease. Changes of tumor volume, contrast enhancement, necrosis, hemorrhage and edema on MRI were compared to changes in 201thallium uptake volumes and 1H-MRS metabolite ratios. Results Six patients were followed with a total of twenty-four examinations with 201thallium SPECT, MRI and 1H-MRS, respectively, between February 1997 and October 1998. Five patients developed clinical progression of disease, 4 out of 5 cases showed SPECT progression, 4 out of 5 cases MRI progression, and 1 out of 2 interpretable cases 1H-MRS progression at final assessment before clinical deterioration. During the phase of clinically stable disease; (A) the criterion for regression or status quo was met in 10 out of 13 assessments with SPECT, 11 out of 13 with MRI, and 8 out of 9 interpretable 1H-MRS; (B) the criterion for progression was met in 3 out of 13 with SPECT, 2 out of 13 with MRI, and 1 out of 9 interpretable 1H-MRS. The accuracy of SPECT, MRI, and 1H-MRS in identifying changes of tumor burden concordant with patients' clinical course was 78%, 83%, and 82%, respectively. SPECT regression was associated with MRI decrease of tumor size, contrast enhancement, edema and hemorrhage. SPECT progression was associated with MRI increase of the same parameters and the increase of necrosis. 1H-MRS regression was associated with decrease of edema. 1H-MRS progression was associated with increase of tumor size, hemorrhage, and increase or decrease of contrast enhancement. Conclusions Both 201thallium SPECT and 1H-MRS evaluation showed sensitivity for detection of astrocytoma progression. We did not find a higher accuracy of SPECT or MRS than of MRI in astrocytoma chemotherapy monitoring. Treatment induced MRI changes were associated with 201thallium uptake variations. 1H-MRS was difficult to apply for astrocytoma treatment monitoring. Improvements regarding size of measurement area such as multivoxel MRS and fat suppression pulses appeared desirable, and also the use of functional techniques with superior resolution such as dual isotope SPECT. However, our results suggest that 201thallium SPECT and 1H-MRS can provide additional information to MRI for chemotherapy efficacy evaluation in selected cases.