Method: To elucidate the predictive factors of high intensity transient signals(HITS), we analyzed 88patients with cerebral infarction or transient ischemic attack(TIA). We performed transcranial Doppler monitoring from the middle cerebral artery(MCA) or basilar artery for 30 min. Results: HITS were detected in 9 (13%) of 67 patients with cereberal infarction, and in 8(38%) of 21 patients with TIA. Overall HITS prevalence was 19%. Multivariate logistic regression analysis revealed that only the infarct/TIA subtype was a significant predictive factor of HITS (p=0.047), and that neither age, sex, TIA, high intensity signals (HIS) found on diffusion-weighted MR imaging (DWI), risk factors for atherosclerosis, the timing of HITS detection, nor medication was significantly linked to HITS. Among the infarct/TIA subtypes, HITS were detected more frequently in patients with hemodynamic/arteriogenic embolic ischemia caused by stenosis in the carotid artery or MCA than in those with cardiogenic embolic and intracranial thrombotic ischemia. Affected patients were significantly young, and cortical/subcortical spotty HIS found on DWI were more frequent in the HITS-positive group. Conclusion: Cerebral ischemia of the hemodynamic/arteriogenic embolic subtype, an age of < 70yr, and cortical/subcortical spotty HIS found on DWI may be predictive factors of HITS.

View full abstract

Purpose: Intima-media thickness (IMT) is widely measured for the evaluation of early atherosclerosis of the carotid artery. However, the accuracy of IMT measurement depends on technical skill and the mechanical resolution of each ultrasonographic device. Thus, development of automatic-measurement software might permit objective assessments and aid comparative evaluations among various examiners or institutes. In this study, we measured IMT using automatic-measurement software and compared the results with those obtained by manual measurement. Methods: The selected subjects were 153 consecutive patients with varying degrees of IMT on the far wall of the common carotid arteries. IMT was determined using the following three measurement procedures: manually, using automatic-measurement software, and manual correction after using the software. Results: A statistically significant correlation was observed between manual and automatic measurements in clear horizontal artery images and plaque images. Manual correction after automatic measurements improved the accuracy for measurements in images of indistinct, diagonal, or serpentine arteries. Conclusion: As long as clear visualization can be achieved, automatic-measurement software can provide accurate IMT values.

View full abstract

The vertebral arterial (VA) pulsed Doppler waveform can indicate the presence of stenosis of the proximal subclavian artery. Systolic dimple sign (SDS), characterized by a sharp decline in velocity at mid systole, is observed when antegrade flow in the VA is preserved. Once subclavian steal occurs, SDS is no longer evident and retrograde flow appears during at systole. Here we report a 65-year-old man suffering from numbness in the left arm and dizziness during left arm activity, in whom serial monitoring of VA flow was performed during percutaneous transluminal angioplasty (PTA). The blood pressure difference between the two upper extremities was 45mmHg, and SDS was documented on pulsed wave Doppler examination. CTA revealed 80% stenosis with calcification in the left subclavian artery. After obtaining informed consent, the left VA flow pattern was monitored (1)before and (2)after predilatation, (3)stenting, and (4)after dilatation of the proximal subclavian artery. The lesion was successfully dilated by balloon angioplasty with stenting. The VA flow pattern gradually normalized as the PTA procedure progressed, showing (1)SDS, (2)normal but slow acceleration time, (3)increased systolic velocity, and (4)normal with rapid acceleration time. VA flow pattern monitoring during PTA is useful for evaluation of hemodynamics in real time.

View full abstract