Absent Middle Cerebral Artery Signal in Transcranial Color-Coded Sonography: A Reliable Indicator of Occlusion?

Chen, Yi Chun; Chen, Sien Tsong; Chen, Chi Jen; Lee, Tsong Hai

doi:10.1159/000087707

Cited by 14 publications

(11 citation statements)

References 52 publications

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“…Moreover, critical carotid stenosis may result in the absence of any MCA signal intensity. 39 Hence, transcranial Doppler sonography is not a very practical tool in assessing CVR in patients with critical carotid stenosis. Measurement of increased CBF by SPECT analysis after administration of vasodilating agents remains the most popular method to interpret CVR.…”

Section: Discussionmentioning

confidence: 99%

Change in Cerebral Perfusion after Carotid Angioplasty with Stenting Is Related to Cerebral Vasoreactivity: A Study Using Dynamic Susceptibility-Weighted Contrast-Enhanced MR Imaging and Functional MR Imaging with a Breath-Holding Paradigm

Chang¹,

Liu²,

Lee³

et al. 2009

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:Carotid angioplasty with stent placement (CAS) is an optional treatment for significant carotid stenosis. Cerebral vasoreactivity (CVR), representing the reserve capacity of cerebral perfusion, usually decreases in patients with severe carotid stenosis. This study aimed to investigate the relationship between the baseline CVR assessed by functional MR imaging (fMRI) and the changes in cerebral blood flow (CBF) after CAS.

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Section: Discussionmentioning

confidence: 99%

Change in Cerebral Perfusion after Carotid Angioplasty with Stenting Is Related to Cerebral Vasoreactivity: A Study Using Dynamic Susceptibility-Weighted Contrast-Enhanced MR Imaging and Functional MR Imaging with a Breath-Holding Paradigm

Chang¹,

Liu²,

Lee³

et al. 2009

AJNR Am J Neuroradiol

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“…Unfavorable conditions of acoustic windows, such as the skull eburnation in some patients, especially in women in the climacteric or menopausal period, caused unclear or absent visualization, and thus contributed to misdiagnosis. Therefore, vascular visualization and consideration of clinical symptoms should both be performed before making a vascular occlusion diagnosis [11]. The location of the stenosed artery played a role in the diagnostic accuracy: foci on MCA are more easily detected.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Transcranial Color-Coded Duplex Sonography for Cerebral Artery Stenosis or Occlusion

Hou

Liu²,

Duan³

et al. 2009

Cerebrovasc Dis

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Backgroundand Purpose: Cerebral artery stenosis or occlusion is the most common etiological factor in patients with acute cerebral ischemia, but the rate of early diagnosis is low. The purpose of the study is to evaluate the diagnostic accuracy of transcranial color-coded sonography (TCCS) for cerebral artery stenosis with digital subtraction angiography used as the gold standard of reference. Methods: Seventy-eight patients who were suspected of cerebrovascular disease were involved in the study. Major cerebral arteries were observed through the transcranial echo window by TCCS. The course, shape of the color blood beam and velocity were given special attention. The hemodynamic parameter was measured and analyzed. The findings of TCCS were compared with the results of digital subtraction angiography, according to a double-blind design. A 4-fold table was used as the statistical analysis method to evaluate TCCS. The indexes included sensitivity, specificity, accuracy and false-positive rate. Results: Imaging of TCCS revealed that the blood flow beam narrowed where the artery had stenosis and looked like girdling. The velocity of the foci increased abnormally, while the velocity before and after the foci decreased. Severe stenosis and the long stenotic segment may show discontinuity of the blood flow beam. The velocity of the foci did not noticeably increase or decrease. The blood flow beam of the occlusive artery cannot be seen and the frequency spectrum cannot be obtained, but the other artery was well visualized at the same time. Analysis of the diagnostic value of TCCS according to the 4-fold table included the validity index, with a sensitivity, specificity, false-positive rate, false-negative rate, accuracy, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio and Youden index of 72.9%, 82.9%, 17.1%, 27.0%, 78.2%, 79.4%, 77.3%, 4.3, 0.3 and 0.56, respectively. The reliability index included the agreement rate and κ value, which were 78.2% and 0.56, respectively. Conclusions: TCCS could be considered a valuable method for the screening diagnosis of cerebral artery stenosis or occlusion.

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“…The benefits of TCCS in detecting MCA stenosis or occlusion have been widely demonstrated [4,7,8,9], particularly when contrast enhancement is used [10, 11]. Similarly, because TCCS is a bedside tool that can be used easily and as needed, it has become the test of choice for evaluating recanalization of the M1 segment after thrombolysis [10, 11].…”

Section: Discussionmentioning

confidence: 99%

Assessment of the Course and Division Patterns of the Middle Cerebral Artery M1 Segment

et al. 2008

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Background and Purpose: The present study was undertaken to assess the ability of bedside transcranial color-coded sonography (TCCS) to define the course and the patterns of the division of the middle cerebral artery (MCA) M1 segment compared with 3D time-of-flight magnetic resonance angiography (MRA) at 3 T. Methods: Because MRA is considered as a reliable noninvasive technique to depict the normal anatomy of the intracranial artery, we prospectively defined the course and the patterns of division of 100 MCA M1 segments using bedside TCCS and compared the results with MRA findings. Results: In 68/85 cases (80%), the sonographer was able to define the division of the M1 segment, and classified these as bipode for 50/68 (73.5%), monopode for 16/68 (23.5%) and tripode for 2/68 (3%). A comparison of the TCCS and MRA findings showed a perfect correlation (100%) for the course of the M1 segment. As for the type of division, the correlation was good in 45/68 of cases (67%). TCCS had a sensitivity of 78%, a specificity of 67%, a positive predictive value of 87% and a negative predictive value of 52%, when used to determine whether the division was bipode or not. Conclusions: Our results show that bedside TCCS can now provide anatomical information on the M1 segment of the MCA.

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Absent Middle Cerebral Artery Signal in Transcranial Color-Coded Sonography: A Reliable Indicator of Occlusion?

Cited by 14 publications

References 52 publications

Change in Cerebral Perfusion after Carotid Angioplasty with Stenting Is Related to Cerebral Vasoreactivity: A Study Using Dynamic Susceptibility-Weighted Contrast-Enhanced MR Imaging and Functional MR Imaging with a Breath-Holding Paradigm

Change in Cerebral Perfusion after Carotid Angioplasty with Stenting Is Related to Cerebral Vasoreactivity: A Study Using Dynamic Susceptibility-Weighted Contrast-Enhanced MR Imaging and Functional MR Imaging with a Breath-Holding Paradigm

Evaluation of Transcranial Color-Coded Duplex Sonography for Cerebral Artery Stenosis or Occlusion

Assessment of the Course and Division Patterns of the Middle Cerebral Artery M1 Segment

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