Transcranial Doppler evaluation of middle cerebral artery stenosis.

Abstract

Symptomatic stenoses of the middle cerebral artery (MCA) are not uncommon, although Corston observed the occurrence of stroke in 24% of patients with MCA stenoses during a 6-year follow-up study. We tried to use transcranial Doppler (fCD) sonography for the detection and evaluation of MCA stenoses.Intra-arterial angiography demonstrated 16 MCA stenoses of more than 30% diameter reduction in 15 patients (14 atheromatous stenoses, 2 dysplasias). Severe as· sedated lesions were present in 2 cases (more than 75% internal carotid artery stenosis). These 15 patients with MCA stenosis were examined with TCD in a blind study.A Doppler signal from the MCA was obtained through the temporal bone and was recognized on the result of common carotid artery compression test. We ascertained MCA stenosis when TCD demonstrated 1) segmental Oow acceleration with peak systolic frequency of more than 3 KHz. with or without high en-T ranscranial Doppler sonography is able to detect and measure blood velocity in the first part of the middle cerebral artery (MCA) in 96% of nor· mal subjects.u However, its accuracy in the detection of MCA stenosis remains to be determined. As reported in x-ray contrast angiographic studies, MCA stenosis is un· common. Hass 3 reported 7.6% "isolated plaques" in more than 4000 intra-arterial contrast angiographies, while Resch' reported 14% MCA plaques in anatomical Received October 13, 1987, from the Cerebral Vascular Investiga~ ergy low frequency direct or reverse components; or 2) segmental increase in systolic peak frequency of more than 20%.Using these criteria, we confirmed through TCD the presence of MCA stenosis in nine out of 12 cases with diameter reduction of at least 50%, and one among four cases with less than 50% diameter reduction.Although our results are consistent with Aaslid and von Reutern's figures, methodological problems and diagnostic criteria have to be improved. Nevertheless, TCD seems to be a useful tool for the detection of stenosis with at least 50% diameter reduction, where it proved to offer a 75% sensitivity. Further studies are necessary to improve sensitivity and specificity. KEY WORDs: transcranial pulsed Doppler sonography, middle cerebral artery stenosis, Intra-arterial angiography. (/ Ultrasound Med 7:6ll, 1988) study on a similar number of cases. MCA stenosis appears to be seldom symptomatic. According to statistical evaluations, s-7 symptoms were found in 2% to 5.7% of cases. Nevertheless, an annual stroke occurrence was reported respectively in 4.2% 1 and 7.8% 9 of patients with MCA stenosis.We attempted to evaluate, in a blind study, the accuracy of transcranial Doppler sonography (TCD) in the detection of angiographically proven MCA stenosis with diameter reduction of more than 30%.

Consensus Recommendations for Transcranial Color-Coded Duplex Sonography for the Assessment of Intracranial Arteries in Clinical Trials on Acute Stroke

“…40 Angle correction reduces the inaccuracy in flow velocity measurements and allows defining diagnostic criteria with a higher sensitivity to detect intracranial arterial narrowing (ie, stenosis, vasospasm). [41][42][43] Angle corrected measurements do not decrease intrarater or interrater reproducibility as compared to noncorrected measurements. 44 -47 …”

Guidelines for the Early Management of Patients With Acute Ischemic Stroke

“…TCD accuracy is less than that of CTA and MRA for steno-occlusive disease, with a sensitivity and specificity of TCD ranging from 55% to 90% and from 90% to 95%, respectively. [269][270][271][272][273][274][275][276] TCD can detect microembolic signals, which are seen with extracranial or cardiac sources of embolism. [277][278][279] In an attempt to better define the accuracy rate of TCD for intracranial stenoses (a common cause of stroke), the Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA) Trial was designed to evaluate the controlled patient population in the Warfarin-Aspirin Symptomatic Intracranial by guest on http://stroke.ahajournals.org/…”

Assessment: Transcranial Doppler ultrasonography: [RETIRED]

“…13,14 Stenosis and occlusion of the ICA siphon, proximal (M1) segment of the MCA, intracranial vertebral artery (VA), proximal basilar artery (BA), and proximal (P1) segment of the posterior cerebral artery (PCA) can be reliably detected by TCD. 1,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] The relative performance of TCD vs MRA, conventional angiography, or DSA varies by center, characteristics and prevalence of disease in the study population, diagnostic criteria, and technical expertise. Sensitivity, specificity, positive predictive value, and negative predictive value of TCD are generally higher in the anterior circulation than in the vertebrobasilar circulation owing to more variable anatomy and technical difficulties in insonation of the vertebrobasilar circulation.…”