[Method of superimposing the angiographically located supratentorial lesion on the scalp prior to craniotomy].

One of the important points in operation of the intracranial supratentorial lesion is appropriate site and size of bony window made by craniotomy and this matter is also important first step in procedure of craniotomy. On the other hand, the site and size of bony window made in craniotomy for supratentorial lesion has relationship with perfectibility of operation. The detail intracranial situation and extent of supratentorial lesion is decided from the datas of various examinations and the findings in cerebral angiogram give a most important and valuable information to the neurosurgeon at present. The neurosurgeons used to decide the area of craniotomy from the findings of cerebral angiogram but there are some difficulty in transfer of findings related with situation of supratentorial lesion in angiogram to the patient's scalp, because the film of cerebral angiography is a projected picture of spheric head by X-ray to the plane. The author devised the planning method of site and size of bony window in craniotomy by transfer the location and extent of supratentorial lesion in cerebral angiogram to the patient's scalp and the author have been recognized for the past five years that this method is simple one and has clinical accuracy. The principle of the author's method are as follows. The film of cerebral angiography in lateral projection and the patient's scalp are divided into nine parts by same manner and the relation of the site and extent of lesion in cerebral angiogram with divided parts transfer to the division of the patient's scalp under special care to make minimize errors due to use the cerebral angiogram which is picture made by projection in a plane from spheric intracranial supratentorial space. Five points and seven lines are used to divide the film of cerebral angiography and the patient's scalp. Five divide points are most upper part of margin of external acoustic meatus, most posterior edge of auricle, upper, lower and lateral edge of orbit. The following divide lines are drawn by use of these five divide points. Two horizontal lines are eye-ear horizontal line and superior eye horizontal line. Three vertical line are external acoustic meatus vertical line, auricular vertical line and temporal orbital margine vertical line. Two oblique lines are anterior and posterior oblique lines. The film of lateral cerebral angiography and patient's scalp are divided into nine parts by these seven divide lines. In the areas above the superior eye horizontal line, following procedure for correction of error due to transfer the point of X-ray film to the patient's scalp is needed because of strong curved brain surface. One end of celluloid or steel scale place closely with the scalp below the superior eye horizontal line and the other end of scale make freely from curved scalp surface. The point of lesion on the divide line of X-ray film marks at correspond point on the scale...