The present study was designed to examine the effect of ultrasound application to the middle cerebral artery (MCA) using transcranial Doppler (TCD) on regional cerebral blood flow (CBF) in ten normal human subjects. We used 99mTc-HMPAO continuous infusion employing the dynamic SPECT method for chronological measurement of regional CBF 10 successive SPECTs in 20 minutes at 2-minute intervals). From the various laminagrams obtained, we divided the regions of interest into ipsilateral cerebral cortices and basal ganglia, and observed the chronological changes in blood flow as well as the changes caused by 2-MHz pulse Doppler ultrasound stimulation of the MCA as a time-activity curve (TAC). ¶Effective increases of rCBF were observed in the temporal lobe (8% increase) and cerebral basal ganglia (12% increase). It was concluded that 2-MHz pulse Doppler ultrasound stimulation of the MCA increased the local cerebral blood flow. These findings indicate the potential usefulness of this approach not only for measurement but also for future therapy.
In an attempt to evaluate the relationship of M1-M2 blood flow velocity to symptomatic vasospasm in the M1-M2 region, transcranial color-coded duplex sonography (TCCS) was performed on patients undergoing craniotomy for anterior circulation aneurysm neck clipping before day 2. During the period from September 2001 to Februarr 2004, TCCS was carried out on 27 SAH patients, who were assigned Hunt & Hess grades 1 to 3. There were 5 men and 16 women, ranging in age from 40 to 81 years (mean 60 years). M2 was identified in 21 patients (77%) by TCCS, and two branches of M2 were identifiable in only 10 of them. Five female patients, aged 51 to 57 years, had symptomatic vasospasm of M2 branches during days 6 to 10. Their Hunt&Hess grades were 2 in four patients and 3 in one. One had a middle cerebral artery aneurysm, 2 had internal carotid-posterior communicating artery aneurysms, and 2 had anterior communicating artery aneurysms. At symptomatic vasospasm their mean peak systolic (PSV) and mean flow velocities (Vm) of M2 were 176±17.3 and 132.6±17.9 cm⁄s, respectively. These were significantly higher than in the other 16 patients without symptomatic vasospasm (PSV: 109.6±109.6±8.5, Vm: 66.9±6.9±5.4 cm⁄s, respectively, p‹0.05). Two patients had M2 vasospasm only, and their PSV and Vm of M2 were higher than those of M1. TCCS is a useful examination for monitoring vasospasm of M2 after SAH. If PSV and Vm of M2 are higher than those of M1, vasospasm of M2 is highly likely.
Achieving tumor resection with as few neurological deficits as possible is the primary goal of brain tumor surgery. Using navigation systems, it is now possible to approach brain tumors more accurately and less invasively, and to resect the tumors more safely using electro-neurophysiological monitoring methods such as SEP, MEP, and ABR. We describe the use of a synchronized navigation system (SonoNavTM), which combines ultrasonography and a navigation system, for real-time monitoring of intraoperative brain shift in addition to the use of these techniques for brain tumor surgery. Before the dural incision after craniotomy, fence post tubes were inserted into the target. The fence post tubes were useful not only for determining the margin of resection, but also for brain shift monitoring. The synchronized navigation system was effective for real-time monitoring of brain shift. The electro-neurophysiological monitoring was effective for preventing neurological deficits after surgery. We conclude that use of a navigation system, ultrasonography and neurophysiological monitoring together contribute to safe, accurate and minimally invasive brain tumor surgery.
This paper describes the detection of microembolism in the ophthalmic artery during carotid artery stenting (CAS). Methods: During the CAS procedure, the ophthalmic artery was examined by color Doppler flow imaging (CDFI) in 18 patients with internal carotid artery stenosis. Ophthalmic artery CDFI provided high intensity transient signals (HITS) and flow direction. Results: Fifteen patients (83%) showed HITS, and HITS was seen in every CAS phase. During the post-dilatation phase with a distal protection system, HITS was significantly more frequent in patients who underwent saline irrigation than in patients who did not (p<0.05). The ophthalmic artery flow direction was abnormal in 10 patients before the CAS procedure. During CAS, the ophthalmic artery flow direction changed in relation to the CAS phase. After CAS, the ophthalmic artery flow direction was normalized significantly in all patients (p<0.05). Conclusion: The presence of microemboli in the ophthalmic artery was proved during the CAS procedure as HITS, and it was clarified that the microemboli entered the intracranial or retinal circulation via the ophthalmic artery. During the post-dilatation phase, saline irrigation was a significant risk factor for embolism even with a distal protection system.
A 37-year-old woman with Takayasu′s arteritis (aortitis syndrome) presented with an absent pulse in her left radial artery. A floating thrombus moving to and fro at the bifurcation of the left common carotid artery was demonstrated by duplex ultrasonography, and was treated successfully by stenting. In this case, ultrasonography proved useful for both diagnosis and follow-up.
We report a 73-year-old woman with antiphospholipid antibody syndrome (APS) complication by systemic sclerosis. She was admitted to our hospital because of sudden onset of right hemiplegia and disturbance of consciousness. On admission, she had right hemiplegia, moderate disturbance of consciousness and global aphasia. Brain MRI and MRA showed high signal intensities in the anterior and posterior watershed areas on diffusion-weighted imaging (DWI) and left internal carotid artery (ICA) occlusion. Carotid ultrasonography (CU), B-mode scan performed on the following day demonstrated a thrombus oscillating with the cardiac cycle on the proximal site of the ICA. No other embolic sources were detected even by echocardiography. Our final diagnosis was embolic stroke with arterial thrombi accompanied by APS. After 6 weeks, CU showed that the thrombus was organized and immobilized. Embolic stroke with APS may be complicated by oscillating thrombus, and CU is thought to be useful for thrombus detection and follow-up.
IMT measurement is useful of the evaluation of early arteriosclerotic change. Using images preserved on IMT equipment, we made a comparison of measurements carried out by three independent examiners. We also carried out measurements using the IMT measurement software installed in the equipment. Two of the three examiners showed good correlation of their measurement values, and a high correlation with the results of automatic analysis was also recognized. Automatic measurement provided a very high correlation with usual measurement when there was no hard plaque. Areas where there was hard plaque or bending did not show a high correlation among the three examiners. These findings highlight the need to improve IMT assessments made by examiners.