Non-invasive external regional measurement of cerebral circulation time changes in supratentorial infarctions using pertechnetate.

Abstract

SUMMARY A method for measuring regional cerebral circulation time (rCCT) between the hemispheres using intravenous pertechnetate and a multidetector system is presented. Interhemlspheric differences of rCCT Instead of absolute values were selected because of the variation of pertechnetate bolus dispersion due to changes In tbe systemic circulation and injection technique Inter-and intraindividually. Time activity curves over one minute were analyzed by a modified gamma function fitting method. The results are printed as a brain map which snows reference values and abnormal findings. Abnormal rCCT asymmetry was observed hi 10 out of 77 controls (13%) and 58 out of 65 patients with cerebral infarction (89%). Within 2 weeks after a stroke shorter circulation time values on the side of the lesion than on the contralateral side were found in 5 patients. In the severe infarction cases and in the acute stages of Infarction circulatory changes could be found In a great number of areas. In patients with manifest diabetes abnormal circulatory findings occurred in larger regions and hi a greater number of the patients than hi those without that disease. Although the luxury perfusion and diaschisis phenomena, as well as the influence of cross-over of the count rates between tbe hemispheres, reduce circulatory time differences, use of the present pertechnetate method allows detection of subtle regional circulatory changes in patients with brain infarction.Stroke 18 Although many regional cerebral perfusion studies using a brain helmet type of multi-detector device have been made, hardly any regional circulation time measurements have been From the Departments of Clinical Chemistry and Neurology, Oulu University Central Hospital, SF-90220 Oulu 22, Finland performed using pertechnetate. Previously the detectors were placed in 2 opposite planes in multiprobe devices but recent developments show a clear tendency towards helmet-type instruments. We have developed our own multidetector device for measurement of regional cerebral circulation time (rCCT) changes in various brain disturbances. In this study quantitative interhemispheric differences of regional Technetium circulation time was examined in patients with brain infarction and in controls. We present distribution of the pathological findings in patients with infarction and the correlation of the results with clinical signs, the time elapsed since infarction, the severity of infarction and the electroencephalographic findings. MethodsThe examination was carried out on 65 patients (26 women, 39 men) with cerebral supratentorial infarctions in Oulu University Central Hospital. Patients ranged from 22 to 82 (mean 55) years of age. The control group consisted of 90 subjects (57 women, 33 men) who did not have structural brain disease and whose age ranged from 15 to 84 years (mean 40). The mean interval between stroke and examination was 2.5 months ranging from one day to 2 years except for one patient who was examined 14 years after stroke.Infarctions were localized on the basi...

The development of nuclear medicine in Finland: a review on the occasion of the 40th anniversary of the Finnish Society of Nuclear Medicine

“…Together with the company Medi‐Valmet a multidetector system (Kefut) was developed. This system was applied to lung function measurements (Holli, 1979), and later in Oulu to brain circulation studies (Ahonen et al ., 1981).…”

Assessment of Cortical Hemodynamics by Multichannel Near-Infrared Spectroscopy in Steno-Occlusive Disease of the Middle Cerebral Artery

“…[5][6][7][8] Among these, time-to-peak (TTP) as a measure for delayed perfusion is sensitive to hypoperfusion and collateral flow as verified in previous studies. 9 In the present study it was evaluated to which extent multichannel NIRS can detect spatial patterns of TTP characteristic for steno-occlusive disease of the MCA.…”