Color Doppler imaging method can describe the blood flow information two dimensionally in real time. Pulsed wave Doppler method is commonly used in the field of examination in neurosonology. Pulsed wave Doppler method detects the Doppler signal from a small volume (sampling volume) selected at a specific depth. Color Doppler imaging method expresses the date of each partial blood flow velocity for many points in color, and displays these color-coded data over the cross-sectional image. The color represents the average of flow velocity components that are included at each point. Because two dimensional blood flow information is obtained in the color Doppler imaging method, it is possible to detect an un-expected blood flow and to be aware of the spatial distribution of the blood flow. New display methods are now available for whole-body color Doppler applications. These new display methods are; “Color Persistence”: to display a persistent image of the blood flow. “Color-angio”: to display the power of the Doppler signal. “3D Color Perspective”: to display the continuity of the blood vessels three-dimensionally.
To clarify the significance of carotid plaques, 98 patients with cerebral thrombosis were studied to examine the infarcted area on computerized tomography (CT) and arteriosclerosis of the peripheral arteries. According to the ultrasonographic findings, the plaques were classified into three types: nodular, homogeneous mural, and mixed plaques. Arteriosclerosis of the limbs was estimated by determination of the ankle pressure index (API) and a low API (less than 0.9) was considered to indicate stenotic lesions of the peripheral arteries. The mean age was 73.3 years in 47 men and 78.1 years in 51 women. CT revealed lacunar infarction in 42, cortical infarction in 38, Binswanger type infarction in 9, and brain stem infarction in 9 cases. Compared to 40 age-matched controls, who had normal findings on CT and API, the incidence of carotid lesions was significantly higher in patients with cerebral thrombosis than that of the controls, especially in patients with Binswanger-type infarction. In 61 cases, there were 108 plaques, consisting of 54 nodular plaques, 41 homogeneous mural plaques, and 13 mixed plaques. Both homogeneous mural and mixed plaques were larger than the nodular plaques, though most plaques were seen in the carotid bifurcation. There was no significant correlation between the infarcted areas and plaque type. Cases of nodular plaque had an API similar to that of patients without plaques (1.00±0.16) . In contrast, homogeneous mural and mixed plaques showed low API values (0.80±0.20 and 0.74±0.23, respectively) . These findings suggest that carotid lesions were not only significantly associated with cerebral thrombosis, but both homogeneous mural and mixed plaques indicate the development of arteriosclerosis.
This phase-two clinical trial was designed to investigate the effectiveness, safety, and usefulness of galactose microparticles (SH/TA-508) as a new ultrasound transpulmonary contrast-enhancing agent for transcranial color flow imaging. Seventy-six patients with clinical indications for transcranial Doppler investigation were entered in this frial. Thirty-eight patients were given an intravenous injection of 8 ml at the concentration of 200 mg/ml, 5 ml at 300 mg/ml, and 4 ml at 400 mg/ml and the other 38 received a two-fold higher volume of the agent at each different concentration. We evaluated the adequacy of signal enhancement and the duration of appropriate signal enhancement on transcranial color-coded flow image after each injection. Safety was determined by clinical and laboratory monitoring for 24 hours. The concentrations of 300 mg/ml and 400 mg/ml were more effective in providing signal enhancement and a long duration of enhancement than 200 mg/ml, and there was no difference in effectiveness between the concentrations of 300 mg/ml and 400 mg/ml. No significant difference in effectiveness was shown between different volumes at the same concentration. Pain at the injection site as an adverse effect was observed in only one patient at injection of 8 ml of 400 mg/ml of the agent. SH/TA-508 was found to be a very useful ultrasound contrast-enhancing agent for transcranial color flow imaging. A suspension of 5 ml of 300 mg/ml seemed to be the optimum volume and concentration for intravenous administration.
The patient was a 52-year-old man, who suddenly developed a severe left hemiparesis. Using transcranial color-flow imaging (TC-CFI), we diagnosed him as having an embolic occlusion of the right MCA M1 segment. After treatment with t-PA, recanalization of the MCA M1 segment was demonstrated by TC-CFI. Two hours after t-PA infusion, his neurological signs were normal. We believe that TC-CFI is very useful in the evaluation of MCA M1 segment occlusion after a hyperacute embolic stroke and the effects of treatment with t-PA.
This study was conductede to evaluate changes of blood flow velocities at different positions in the same artery. The subjects were 12 normal neonates, aged 8 to 189 hours. We examined cerebral blood flow velocity at eight points (5 proximal and 3 distal regions) on the anterior cerebral artery (ACA) and four points on the basilar artery (BA) by pulsed Doppler sonography under color Doppler guiding, model Aloka SSD 870. The blood flow velocities and resistance indices (RI) at proximal ACA ranged from 39.33 to 42.42 cm/sec and from 0.71 to 0.73 respectively, and those at BA were from 40.83 to 47.42 cm/sec and from 0.71 to 0.74, respectively. These scores were not statistically different. There has been little atteation paid to positional differences in the blood flow velocities and RIs in measuring proximal ACA and BA. These arteries may be influenced mainly by the cardiac pump function. On the other hand, the velocities and RIs on distal ACA were lower than those on proximal ACA. Sampling scores were gradually decreased from the proximal to the distal portions on the distal ACA. Flow patterns of the distal portion of ACA may reflect peripheral vascular resistance.