Background: Three-dimensional ultrasonography (3D-US) has been recently developed and used mainly in the gynecological field. We have performed 3D-US examination of carotid artery lesions. Here we present an analysis of comparison with 2D-US. Materials and methods: We used three kinds of 3D-US machines (TOSHIBA SSA-700A, ALOKA SSD-5500 EX-3D5500 EX-3D, and PHILIPS HDI-5000 SONO CT) to examine atherosclerotic lesions of the carotid artery in 47 patients (37 men and 10 women; average age 70). Moreover, pathological findings of carotid endarterectomy specimens were also analyzed and compared with the 3D-US image in four cases. Results: We were able to visualize the lesions from multiple directions by 3D-US by a technical procedure after detecting each lesion in an axial view. 3D-US was particularly effective for recognizing ulceration by multidirectional view. The image corresponded to pathological findings in the carotid endarterectomy specimen. Conclusion: It is usually difficult to detect carotid lesions from all directions by usual 2D-US, because of the many tissues that surround and mask the carotid artery. 3D-US is useful for recognizing carotid lesions. The most diagnostically useful lesion is ulceration, which cannot be seen by axial view alone. 3D-US is considered to contribute to the diagnosis of carotid lesions.
Arteriosclerosis of the vertebral artery preferentially affects the area near its origin, and sometimes can become a cause of embolism. The purpose of this study was assess the validity of conventional color Doppler sonography compared to selective angiography for evaluating the origin of the vertebral artery. A retrospective study of 120 vertebral arteries was undertaken. Sixty patients with cerebrovascular disorders were studied by conventional color Doppler sonography and selective arterial angiography. The lesions were classified into 6 groups morphologically on the basis of angiography: normal, hypoplastic, occluded, kinked, coiled and stenosed. Color Doppler imaging enabled good documentation of vertebral artery flow on the right in 93% and on the left in 97%, and of the vertebral artery wall on the right in 70% and on the left in 52 (<0.05). Occlusion and hypoplasty were detected in all 15 vessels with a specificity of 94.3%, but false positive results were obtained in one vessel due to technical difficulties. Thirteen of these 15 vessels were kinked and coiled. Moderate stenosis (<70%) could not be evaluated, but stenosis exceeding 80% was diagnosed in two cases with a specificity of 100%. Diagnosis of moderate stenosis of the origin of the vertebral artery remains difficult. Duplex sonography seems a viable option for evaluation of the vertebral artery, and for quantifying vertebro-basilar stroke.
We attempted to evaluate the function of ophthalmic artery (OA) flow as the collateral pathway in cases of internal carotid artery occlusion (ICAO). Methods. We examined 18 patients having symptomatic ICAO who underwent OA color Doppler flow imaging (CDFI) and quantitative SPECT regional cerebral blood flow (rCBF)study. Results. (1) The OA CDFI findings were reversed OA flow in 10 patients and antegrade flow in 8. (2) The mean resting rCBF was 25.2ml/100 g/min in the patients with reversed OA flow, and 26.7 ml/100 g/min in the patients with antegrade OA flow. The mean cerebral blood flow reserve capacity with acetazolamide was 8.68% in the former and 28.3% in the latter. This difference was statistically significant (p<0.05). (3) In eight patients with severe hemodynamic compromise with a cerebral blood flow reserve capacity of less than 10% and a resting rCBF of less than 80%, the reversed OA flow was visualized significantly frequently (p<0.05). Conclusion. In ICAO patients, OA CDFI findings are well correlated with the hemodynamic stage and development of other collateral pathways. Reversed OA flow indicates severe intracranial hemodynamic compromise.
Four-dimensional reconstructions of power flow Doppler images disclosed the differences in pulsatility patterns between normal neonates and neonates with asphyxia. The differences could not be explained by conventional quantative analysis, including blood velocity, resistance index and pulsatility index. There was a minor difference in pulsatility patterns by four-dimensional analysis of PF between two normal neonates. Wavelet analysis disclosed a difference between the two neonates in signal intensity at levels 5 and 6 by use of the Gabor 8 function. There was a positive correlation between the signal intensity in end-diastolic phase at levels 5 and 6 by Gabor 8 and the intensity of the pulsatility patterns in four-dimensional analysis. There were strong bands at levels 5 and 6 in twelve normal neonates, but weak bands in four neonates with asphyxia.
Subclavian steal syndrome is a phenomenon arising from stenosis or obstruction of the subclavian artery proximal to the vertebral artery. Carotid ultrasonography has long been used for the identification of this phenomenon. However, the efficacy of transesophageal echocardiography (TEE) for the identification of subclavian steal syndrome has not been established. We present a case in which TEE was used for the identification of subclavian steal syndrome confirmed by angiography in a patient with transient ischemic attack. A 63-year-old man with a history of untreated hypertension was transferred for evaluation of transient right arm weakness. Neither brain CT nor MRI identified any acute ischemic lesion. A carotid ultrasound and cerebral angiographic examination revealed retrograde flow in the left vertebral artery, and subclavian steal syndrome was suspected. TEE was done to evaluate the left subclavian artery and to rule out any embolic source in the heart and aortic arch. TEE revealed occlusion of a long segment of the proximal left subclavian artery by isoechoic intramural plaque, and color/pulse wave Doppler examination of the proximal left vertebral artery revealed reversal of flow suggestive of steal syndrome. TEE represents an additional ultrasound approach for noninvasive assessment of subclavian steal syndrome.
A 75-year-old male patient presented with sluggish speech and left hemiparesis. Brain magnetic resonance imaging (MRI) revealed acute multiple brain infarctions adjacent to both lateral ventricles. Although the patient received anticoagulant therapy, he exhibited fluctuations in his level of consciousness and hemiparesis. Carotid ultrasonography revealed severe stenoses and diffuse smooth-surfaced plaque in the bilateral common carotid artery, with laminated but relatively homogeneous, low-level internal echoes. These observations suggested dissecting aortic aneurysm. A diagnosis of Stanford type A dissection was made based on the results of contrast-enhanced computed tomography (CT) scans from the neck to the pelvis, and therefore emergency surgery was performed. Although rare, central nervous system symptoms can be the initial manifestation of this disease without typical chest pain, causing a delay in diagnosis. In the present case of dissecting aortic aneurysm, the initial symptom was left hemiparesis without chest pain, and the diagnosis was made successfully by carotid ultrasonography.