Intraoperative spinal sonography was used in 95 spinal lesions including 44 spinal cord tumors and 37 syringomyelias. Syrinxes and cysts were anechoic and as a result the septum in the syrinxes could be detected, but the small cysts could not be detected. Intradural extramedullary tumors were hyperechoic and were visualized clearly because the contrast with the anechoic CSF around them was clear. Central echoes in these cases were observed near the tumors. But the central echoes of intramedullary tumors could not be obtained over the wide tumor area. Ependymoma and hemangioblastoma were hyperechoic because the rostral or caudal cysts were anechoic. But in some cases of hemangioblastoma, they were not so hyperechoic and not well-demarcated because their cysts were small. Astrocytoma was irregularly hyperechoic and the boundary of the tumor was not clear. In order to demonstrate the lesions more clearly, a high frequency probe is needed, and a smaller probe is needed so that it can be used through a small incision.
The quantitative blood velocity of MCA (Ml and M2) and BA was noninvasively measured by utilizing the color capture method (CC method) for the transcranial color flow images (TC-CFI) . This CC technique, which was supplied by ATL Ultramark 9, featured a display of one projected image of the CFIs which were memorized in one cine-loop during the displacement of the probe along the axis perpendicular to the horizontal image of the brain. This projected image indicating cerebral arteries and veins was very useful in setting the Doppler sample volume for the desired artery. Also the image could be used to determine the Doppler beam angle for the velocity calculation which could not be actualized in the TCD application. The velocity of Ml was measured at a distal location 3 cm from the ACA-MCA bifurcation through the temporal bone. Also M2 velocity was measured at a distal location 2 cm from the M1-M2 bifurcation. The BA velocity was measured at 1.5 cm from the junction of both vertebral arteries. The data obtained from 13 young subjects (mean age : 20.7 y.o.) were mean M 1 velocity : 42.7 ±6.7 cm/s mean M2 velocity : 24.9± 8.8 cm/s mean BA velocity : 18.6±4.1 cm/s The mean velocity was calculated by multiplying 0.5 to the mean velocity of the peak velocity pattern over one cardiac cycle of the Doppler sonogram, in order to compensate the parabolic velocity profile in the vessel lumen. It was also verified through TC-CFI and CC methods that the Doppler beam angular correction technique was indispensable in the velocity measurement of MCA on the temporal bone. On the contrary, this angular corection technique was not necessary in the BA measurement in the occipital region, because the velocity error due to the beam angle was minimal. Accordingly it was noticed that previous data concerning BA could be used as the true blood velocity within a permissible error. The above data can be used as the standard value of MCA and BA flow velocity of young adults.
Using transcranial Doppler sonography (TCD) and angiography, we studied the hemodynamics of basal cerebral arteries of one patient with a carotid-cavernous sinus fistula (CCF) after internal carotid artery (ICA) embolization. The patient suffered traumatic left CCF and was treated with complete ICA embolization. The results of TCD using commom carotid artery compression in measuring the blood flow velocity of vertebral, ophthalmic and middle cerebral arteries were mostly in accordance with those of the angiography. However, comparing TCD with angiography, TCD is noninvasive and involves only a simple physiologi-cal examination, so by using TCD we can accurately diagnose and follow up cases such as this patient, easily and frequently.