The purpose of this study was to determine the efficacy of using an ultrasound contrast agent(levovist)to enhance the color Doppler imaging of liver neoplasms.Thirty patients with hepatic tu...The purpose of this study was to determine the efficacy of using an ultrasound contrast agent(levovist)to enhance the color Doppler imaging of liver neoplasms.Thirty patients with hepatic tumors were enrolled in this study.After intravenous administration of levovist,the color Doppler signals of normal hepatic vessels were enhanced.In various hepatic tumors,the different patterns of tumor vascularity were observed,which had not been demonstrated in conventional non contrast color Doppler imaging.In 11 of 16 patients with hepatocarcinoma,additional color Doppler signals were observed in the central part of the tumors.On the contrary,3 patients with metastatic liver lesions the enhanced color Doppler signals appear only at the peripheral of tumors.A typical rim like color enhancement was seen in 2 of the 3 cases.In six patients with hepatic hemangiomas contrast enhanced color Doppler imaging demonstrated the blood vessels at the margin of the neoplasms.Contrast enhanced color Doppler imaging improves the visualization of the hepatic neoplasm vascularity.This technique holds great promise for detecting small liver tumors and differentiating hepatic neoplasms.展开更多
Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using ...Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using TCD ultrasound to detect the flow velocity and waveform patterns of middle cerebral artery (MCA) and basilar artery (BA) in patients with PVS, locked in syndrome and brain death. Results. The mean velocities of middle cerebral artery (Vmca) and basilar artery (Vba) were 30.0cm/s and 24.3cm/s in PVS patients respectively, which decreased 45.0% and 14.4% in comparing with normal value. For patients with locked in syndrome, Vmca and Vba were 49.7cm/s and 9.8cm/s, which decreased 5.0% and 61.7% than the normal value respectively. These results showed that the decrease of anterior circulation was predominant in PVS, and the decrease of posterior circulation was predominant in locked in syndrome. A unique diastolic reverse flow, short peak systolic wave or undetectable flow signal in middle cerebral artery were predominant in brain death patients, which was completely different from that of either PVS or locked in syndrome. Conclusion. TCD was a valuable tool in distinguishing PVS, locked in syndrome and brain death patients according to the differences in velocities and patterns of anterior and posterior cerebral arteries.展开更多
Objective. To evaluate the diagnostic criteria for the localization of acquired arteriovenous fistulas (AVFs) by color Doppler flow imaging (CDFI) based on the features of their hemodynamic changes. Methods. The shape...Objective. To evaluate the diagnostic criteria for the localization of acquired arteriovenous fistulas (AVFs) by color Doppler flow imaging (CDFI) based on the features of their hemodynamic changes. Methods. The shape and hemodynamic changes of involved vessels which could be helpful to localize the sites of fistulas were studied according to the observation of 10 cases of acquired AVFs. Results. The sites of the fistulas could be shown by two dimensional ultrasonography and color flow imaging in 40%and 80%cases, respectively. In all cases, turbulent high velocity flow was present at the sites of the fistulas, low resistant flow was present in the arteries proximal to the fistulas, and artery like flow was detected in the veins. Conclusion. CDFI was accurate for the localization of acquired AVFs, which were mainly localized by their hemodynamic changes shown by pulse Doppler ultrasound.展开更多
文摘The purpose of this study was to determine the efficacy of using an ultrasound contrast agent(levovist)to enhance the color Doppler imaging of liver neoplasms.Thirty patients with hepatic tumors were enrolled in this study.After intravenous administration of levovist,the color Doppler signals of normal hepatic vessels were enhanced.In various hepatic tumors,the different patterns of tumor vascularity were observed,which had not been demonstrated in conventional non contrast color Doppler imaging.In 11 of 16 patients with hepatocarcinoma,additional color Doppler signals were observed in the central part of the tumors.On the contrary,3 patients with metastatic liver lesions the enhanced color Doppler signals appear only at the peripheral of tumors.A typical rim like color enhancement was seen in 2 of the 3 cases.In six patients with hepatic hemangiomas contrast enhanced color Doppler imaging demonstrated the blood vessels at the margin of the neoplasms.Contrast enhanced color Doppler imaging improves the visualization of the hepatic neoplasm vascularity.This technique holds great promise for detecting small liver tumors and differentiating hepatic neoplasms.
文摘Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using TCD ultrasound to detect the flow velocity and waveform patterns of middle cerebral artery (MCA) and basilar artery (BA) in patients with PVS, locked in syndrome and brain death. Results. The mean velocities of middle cerebral artery (Vmca) and basilar artery (Vba) were 30.0cm/s and 24.3cm/s in PVS patients respectively, which decreased 45.0% and 14.4% in comparing with normal value. For patients with locked in syndrome, Vmca and Vba were 49.7cm/s and 9.8cm/s, which decreased 5.0% and 61.7% than the normal value respectively. These results showed that the decrease of anterior circulation was predominant in PVS, and the decrease of posterior circulation was predominant in locked in syndrome. A unique diastolic reverse flow, short peak systolic wave or undetectable flow signal in middle cerebral artery were predominant in brain death patients, which was completely different from that of either PVS or locked in syndrome. Conclusion. TCD was a valuable tool in distinguishing PVS, locked in syndrome and brain death patients according to the differences in velocities and patterns of anterior and posterior cerebral arteries.
文摘Objective. To evaluate the diagnostic criteria for the localization of acquired arteriovenous fistulas (AVFs) by color Doppler flow imaging (CDFI) based on the features of their hemodynamic changes. Methods. The shape and hemodynamic changes of involved vessels which could be helpful to localize the sites of fistulas were studied according to the observation of 10 cases of acquired AVFs. Results. The sites of the fistulas could be shown by two dimensional ultrasonography and color flow imaging in 40%and 80%cases, respectively. In all cases, turbulent high velocity flow was present at the sites of the fistulas, low resistant flow was present in the arteries proximal to the fistulas, and artery like flow was detected in the veins. Conclusion. CDFI was accurate for the localization of acquired AVFs, which were mainly localized by their hemodynamic changes shown by pulse Doppler ultrasound.
