Ο διά ραδιενεργού 133Xe προσδιορισμός της εγκεφαλικής αιματικής ροής

Abstract

The object of the present investigation has been the determination of the rCBF on 34 cases with normal hemisphere and on 71 cases with intracranial tumors (34 gliomas, 21 metastases, 16 meningiomas). The patients of the first category were admitted in our Hospital with suspected cerebral lesion, but the radio-isotopical and neuroradiological examinations proved to be normal. The blood flow study in all the patients was performed a few days after the γ - encephalography and immediately before the arteriography. In the patients of the second categoty the localization of the tumor was obrtained with γ - encephalography. The patients of both categories received only a local anaesthetic of 1% procaine Hydrochloride for the carotid puncture and all (except a few cases of tumors with somnolence) were awakened and relaxed during the period of our measurements. For this aim we used the interacarotid injection method with radioactive Xenon The 133Xe (2mc in5ml normal saline) was introduced in the internal carotid artery via a thin polyethelen catheter. Thereafter the clearance of 133Xe from the cerebral hemisphere has been observed by 6 collimated detectors placed in the lateral aspect of the skull and was monitored for ten minutes. From the extracranialy recorded curves we have calculated the rCBF1 0 , according to principle of stochastic analysis as modified by Zierler (1965). We have also calculated the rCBF by analysis (the first two minutes) of the 133Xe clearance curves logarithmically recorded. The results of our study are the following I. On the 34 cases proved as normal : (a) A mean value rCBF 49,6±8,1 ml/100 g/min was obtained. This value was correlated by statistical analysis based on 117 cases of 11 samples from an equal number of investigators. The above value proved to be the outcome of symmetrical partial values and includes the limits between 47,6 - 50.6 which are the average of 117 cases in all. (b) Regional differences of cerebral blood flow in the hemisphere were observed. High values were found in the insular and precentrai regions and low valueswere obtained in the inferior temporal and callosal regions. (c) The Hypercapnia test was applied in 15 out of 34 cases and was found a mean value of increase 33.2%. Π. On the 71 cases with intracranial tumors.We have originally measured the rCBF of the pathological hemisphere on three groups of the tumors (gliomas, metastases, menigiomas) and we found a mean value 38,5±7,4 ml/100 g/min. Therafter measurements on each group of the tumors, were attained as follows : A. GLIOMAS (a) We have calculated the rCBF on 34 cases of gliomas and we found a mean value 34,9±7,1 ml/100 g/'in. (b) The rCBF on glioblastomas (12 cases) and astrocytomas (21 cases) was eventually measured. The mean'value, found to be 33,6±5,8ml/100 g/min and 35,9 ±7, 4 respectively. (c) The gliomas with and without papilledema were also investigated. The mean value was 30.7±5,6 ml/100 g/min in the first and 36,8±11,4 ml/100 g/min for the latter. (d) A fourth measurement of this group of tumors has been attained, namely : The separated calculations of the rCBF over the tumor, in the peritumoral tissue and in regions of some distance from the tumors. The following mean values were found : over the tumor 33,7±6,5 ml/100 g/min inperitumoral tissue 32,5±5,9 ml/100 g/min in the tissue of some distance from the tumor 38,2±6,3 ml/100 g/min. (c) Finally an estimation of the reaction in C02 of all pathological hemisphere as well as of the regions lied away from the tumor has been obtained. A mean value of increase 16,1% and 18,0% was found respectively. B. METASTASES (a) On this group of the metastatic tumors (21 cases) a mean valve rCBF 33,5±5,2 ml/100 g/min was found. (b) The rCBF on the tumor in the peritumoral tissue and in the regions of some distance from the tumor was also measured. The following mean values were found 32,8±3,2— 31,3±4,5,—37,2±6,8 ml/100 g/min respectively. (c) The metastatic tumors in the brain, those with papelledema and without were measured. The mean value was 30,1 ±4,3 in the first and 35,5±4,9 ml/100 g/min for the latter. (d) The mean value of the increase rCBF after administration C02 found to be : 15,4% for all pathological hemisphere and 16,1% for the regions of some distance from the tumor. C. MENINGIOMAS (a) The mean value of rCBF on this group of the tumors (16 cases) found to be higher than the mean values of other two groups of the tumors, namely 47,1 ± 13 ml/ 100 g/min. (b) The separated measurements of rCBF over the tumor in the peritumoral tissue and in the regions of some distance from the tumor were perfomed. The following mean values were given 51,4±14,4 — 45,4±10;3 — 47,2±10,8 respectively. (c) The mean value of the increase rCBF after administration C02 found to be also higher than the other two groups of the tumors. Namely 18,1% for all patholog cal hemisphere and 19,8% in the regions of some distance from the tumor. Therefore, according to our measurements the lower values of rCBF were observed in the glioblastomas and in the metastases and the higher in meningiomas. From the separated measurements over the tumor in the peritumoral tissue and in the regions of some distance from the tumor was found that the more injured tissue is the peritumoral one, in which was measured the lower value of rCBF.

Έ κ της όλης μελέτης προκύπτουν τά ακόλουθα συμπεράσματα : 1. Ή ευρεθείσα ύφ' ημών μέση τιμή rCBF 49,6±8,1 ml/100 g/min, επί των θεωρηθέντων ώς· φυσιολογικών περιπτώσεων προέρχεται έκ συμμετρικών έπί , μέρους τιμών. Ωσαύτως δέ περιέχεται μεταξύ των ορίων 47,6 και 50,6, εις τα όποια,ευρίσκεται ή μέση τιμή ενός πλήθους 117 περιπτώσεων εξ ένδεκα δειγμάτων. 2. "Ολαι αί περιοχαί τοΰ ημισφαιρίου δεν έχουν τήν αυτήν τιμήν αιματικής ροής. Αί μεγαλύτεραι τιμαί εμφανίζονται εις τήν ΐνσουλαν καί προκεντρικήν χώραν, αί δέ μικρότεραι είς τήν περιοχήν τοΰ μεσολοβ'.ου και τήν κάτω κροταφικήν χώραν. 3. Κατά τήν δοκιμασίαν της ύπερκαπνίας προεκλήθη αυξησις του rCBF εις το ήμισφαίριον ίση περίπου προς το τρίτον της μέσης φυσιολογικής τιμής rCBF. 1. Tò rCBF επί τών όγκων εν γένει είναι χαμηλότερον αύτοϋ του φυσιολογικού εγκεφαλικού ίστοϋ. 2. Ή χαμηλότερα τιμή rCBF παρατηρείται είς τάς μεταστάσεις καί τα γλοιοβλαστώματα. 3. Ή υψηλότερα τιμή rCBF εμφανίζεται είς τά μηνιγγιώματα. 4. Κατά τάς κεχωρισμένας μετρήσεις του rCBF έπί του όγκου πέριξ του όγκου καί μακράν αύτοϋ απεδείχθη ότι ό πλέον βεβλαμμένος ίστος είναι ό περιογκικός, ένθα ευρέθη καί ή μικρότερα τιμή rCBF. 5. Tò rCBF είναι μικρότερο ν εις τά περιστατικά εκείνα τών εγκεφαλικών όγκων, τά όποια εμφανίζουν ενδοκράνιον ύπέρτασιν. 6. Ή άντίδρασις τών εγκεφαλικών αγγείων εις τό C0 2 επί όλων τών περιπτώσεων ένδοκρανιακών όγκων είναι διάφορος αυτής τών φυσιολογικών περιπτώσεων.