| Abstract: | A radionuclide, when injected intrathecally, normally does not enter into the ventricle system. In our three cases of intra cerebral-ventricular pneumocephalus the radionuclide entered into the ventricle and concentrated in the cyst. Such an abnormal movement of the radionuclide was generally caused by the obstruction of subarachnoid space and the increased C.S.F. absorption in the enlarged ventricle. Under consideration of the pre-and post-operative cisternograms of our three cases we examined the principal factor which brought on the abnormal movement of a radionuclide. Each principal factor was the excessive C.S.F. rhinorrohea in the first case, the increased C.S.F. absorption in the enlarged ventricle and the cyst in the third case. An analysis of our three cases shows that the accumulation of radionuclide into the ventricle system is not necessarily due to the obstruction of subarachnoid space, but also due to more C.S.F. absorption in the ventricle system than that in the subarachnoid space. |
