For the intraoperative ultrasound monitoring, we have investigated to minimize the size of a sector type probe and have clinically applied it in several neurosurgical procedures, particularly in cases of deep-seated-brain tumors. The ultrasound monitoringwith our newly developed sector probe can provide many useful informations in real time during the operation for deep-seated lesions. The sector probe is 14mm in outer diameter and is working in 5 MHz. Combined use of the ISEKI-stereotactic apparatus and the ultrasonography with this sector probe provided beneficial informations for stereotactic biopsy or deep brain surgery, since it has the potential to identify anatomical localization of a tumor or other lesions at any time during surgical manipulations. We have also developed a rotating ultrasound probe turning around by a computer-controled stepping motor. By using this rotating ultrasound probe, it was possible to visualize intracerebral lesions tangentially and it's surrounding anatomical structures in round-shaped area, approximately 2 cm in diameter along one trajectory of the probe. Our newly developed intraoperative monitoring system is an useful tool for stereotactic biopsy or neurosurgery of deep-seated brain tumors or other lesions.
Cerebral blood flow changes during the mastication were measured by the transcranial Doppler ultrasound (TCD) . The mean blood flow velocities (Vm) of the middle cerebral artery (MCA) in 17 normal subjects were measured before and during the mastication of cooked cleaned rice, uncleaned rice, softbread and French bread. Moreover, the blood flow during continuous grasping of both hands was measured to compare with the blood flow during mastication. The Vm during the load (Vm (during) ) was compared with the prevalue (Vm (pre) ) and the rates of the changes were calculated as [Vm (during) /Vm (pre) ] ×100 (%) . In 10 normal subjects, the Vm of the basilar artery (BA) was measured before and during mastication. In 5 patients, the diameters of the MCA were measured on the angiogram before and during mastication. The rate of flow velocity change during the mastication increased to 124-133%. The flow velocity of the BA did not show significant changes, therefore the increase of the Vm of the MCA was not caused simply by a regular cardiovascular response to increased activity but a more focal effect caused by the brain itself. The diameter of the MCA also showed no significant changes during the mastication. It means not only the flow velocity but also the blood flow volume increased during mastication. The close relationship between cerebral blood flow and mastication was recognized.
A study to determine the safety and usefulness of a ultrasonic contrast agent SH/TA-508 was made at 11 institutions across the country in 108 patients who needed the diagnosis of cerebrovascular disorders by means of the transcranial Doppler method. The patients first received SH/TA-508 in a volume of 5 ml at a concentration of 300 mg/ml. When the first dose failed to yield a good effect, they further received 4 ml at a concentration of 400 mg/ml as a second dose, followed by, if necessary, 10 ml at the concentration of 300 mg/ml or 8 ml at the concentration of 400 mg/ml. The signal enhancement was evaluated in four grades: - (no effect), + (poor), 2+ (adequate), and 3+ (excessive) . A response rate (the percentage of“2+”or more) was obtained in 79.0% with the first injection. The cumulative response rate with the second and the third injection amounted to 83.9% and 86.2%, respectively. The duration of the signal enhancement was assessed as “good” in 67.0% with the first injection, increasing to 78.5% after the second injection and to 83.9% after the third injection. In short, a good signal enhancement lasting long enough could be obtained with SH/TA-508 in an initial volume of 5 ml at a concentration of 300 mg/ml. When this first dose failed to yield a good effect, the signal enhancement was found improved to some extent with an additional 4 ml at a concentration of 400 mg/ml. The diagnosis with the use of SH/TA-508 was assessed as “obviously improved” in 78.8%. Further, SH/TA-508 was assessed as safe in 92.3% of the patients as there were no serious side effects observed. One patient complained of malaise as a moderate side effect, but it was not a serious one and spontaneously disappeared without special treatment. This patient also suffered aggravation of liver function; as the causal association with SH/TA-508 could not be totally denied, the patient was classified into “safety questionable” in safety evaluation. There were several other patients who complained of pain or burning sensation; the incidence of side effects was eventually concluded as 7.7%. Based on all of these results together, SH/TA-508 was concluded as either “very useful” or “useful” in 82.2%. In conclusion, SH/TA-508 may be expected as a clinically useful ultrasonic contrast agent since the agent has no significant safety problem and may be expected to yield a good signal enhancement and a more reliable diagnosis when used in the transcranial Doppler method for cerebrovascular disorders.