Screening for intracranial stenosis with transcranial doppler

The accuracy of mean flow velocity thresholds

Robert A. Felberg, Ioannis Christou, Andrew M. Demchuk, Marc Malkoff, Andrei Alexandrov

Research output: Contribution to journalArticle

75 Citations (Scopus)

Abstract

Background. Patients with 50% intracranial arterial stenosis may require more intensive therapies for stroke prevention. Transcranial Doppler (TCD) is a convenient noninvasive screen for intracranial stenosis. The accuracy of different mean flow velocity (MFV) thresholds for determining the degree of stenosis remains uncertain. Methods. The authors prospectively compared the accuracy of TCD criteria and MFV thresholds to magnetic resonance, computed tomography, and digital subtraction angiography in patients with symptoms of recent or remote stroke or transient ischemic attack. Stenosis on angiography was measured as 0%, <50%, or ≥50% diameter reduction. Results. Of 136 consecutive patients, 33 (24%) had distal internal carotid artery (ICA), middle cerebral artery (MCA), posterior cerebral artery, or basilar artery stenosis on angiography (14 patients [10%] were excluded due to incomplete TCD examinations, mainly from a lack of temporal windows). TCD showed 31 true-positive, 9 false-positive, 2 false-negative, and 94 true-negative studies. For all vessels, TCD had a sensitivity of 93.9% (confidence interval [CI] = 89%-98%), a specificity of 91.2% (Cl = 87%-96%), a positive predictive value (PPV) of 77.5%, and a negative predictive value (NPV) of 97.9%. The trade-off in sensitivity and specificity for MCA MFV thresholds was as follows: MFV≥ 80 cm/s had a sensitivity of 100%, a specificity of 96.9% (Cl = 94%-99%), a PPV of 84%, and an NPV of 100%. MFV ≥ 100 cm/s had a sensitivity of 100%, a specificity of 97.9% (Cl = 96%-99%), a PPV of 88.8%, and an NPV of 94.9%. MFV≥ 120 cm/s had a sensitivity of 68.7% (Cl = 61%-78%), a specificity of 100%, a PPV of 100%, and an NPV of 94.9%. Reasons for false-positive findings include collateralization of flow in the presence of proximal ICA stenosis and prestenotic to stenotic MCA velocity ratios of 1:≤2. Conclusion. TCD is both sensitive and specific in identifying ≥50% intracranial arterial stenosis. A MFV threshold cutoff of 100 cm/s has an optimal sensitivity and specificity trade-off for ≥50% MCA stenosis. To help avoid false-positive results, a prestenotic to stenotic MCA velocity ratio of 1:≥2 should be used in addition to the MFV threshold.

Original languageEnglish (US)
Pages (from-to)9-14
Number of pages6
JournalJournal of Neuroimaging
Volume12
Issue number1
DOIs
StatePublished - Jan 1 2002
Externally publishedYes

Fingerprint

Middle Cerebral Artery
Pathologic Constriction
Angiography
Stroke
Vertebrobasilar Insufficiency
Posterior Cerebral Artery
Sensitivity and Specificity
Digital Subtraction Angiography
Carotid Stenosis
Transient Ischemic Attack
Internal Carotid Artery
Magnetic Resonance Spectroscopy
Tomography
Confidence Intervals

All Science Journal Classification (ASJC) codes

  • Radiology Nuclear Medicine and imaging
  • Clinical Neurology

Cite this

Screening for intracranial stenosis with transcranial doppler : The accuracy of mean flow velocity thresholds. / Felberg, Robert A.; Christou, Ioannis; Demchuk, Andrew M.; Malkoff, Marc; Alexandrov, Andrei.

In: Journal of Neuroimaging, Vol. 12, No. 1, 01.01.2002, p. 9-14.

Research output: Contribution to journalArticle

@article{2db831d1f0eb4e46a547bc5c03090688,
title = "Screening for intracranial stenosis with transcranial doppler: The accuracy of mean flow velocity thresholds",
abstract = "Background. Patients with 50{\%} intracranial arterial stenosis may require more intensive therapies for stroke prevention. Transcranial Doppler (TCD) is a convenient noninvasive screen for intracranial stenosis. The accuracy of different mean flow velocity (MFV) thresholds for determining the degree of stenosis remains uncertain. Methods. The authors prospectively compared the accuracy of TCD criteria and MFV thresholds to magnetic resonance, computed tomography, and digital subtraction angiography in patients with symptoms of recent or remote stroke or transient ischemic attack. Stenosis on angiography was measured as 0{\%}, <50{\%}, or ≥50{\%} diameter reduction. Results. Of 136 consecutive patients, 33 (24{\%}) had distal internal carotid artery (ICA), middle cerebral artery (MCA), posterior cerebral artery, or basilar artery stenosis on angiography (14 patients [10{\%}] were excluded due to incomplete TCD examinations, mainly from a lack of temporal windows). TCD showed 31 true-positive, 9 false-positive, 2 false-negative, and 94 true-negative studies. For all vessels, TCD had a sensitivity of 93.9{\%} (confidence interval [CI] = 89{\%}-98{\%}), a specificity of 91.2{\%} (Cl = 87{\%}-96{\%}), a positive predictive value (PPV) of 77.5{\%}, and a negative predictive value (NPV) of 97.9{\%}. The trade-off in sensitivity and specificity for MCA MFV thresholds was as follows: MFV≥ 80 cm/s had a sensitivity of 100{\%}, a specificity of 96.9{\%} (Cl = 94{\%}-99{\%}), a PPV of 84{\%}, and an NPV of 100{\%}. MFV ≥ 100 cm/s had a sensitivity of 100{\%}, a specificity of 97.9{\%} (Cl = 96{\%}-99{\%}), a PPV of 88.8{\%}, and an NPV of 94.9{\%}. MFV≥ 120 cm/s had a sensitivity of 68.7{\%} (Cl = 61{\%}-78{\%}), a specificity of 100{\%}, a PPV of 100{\%}, and an NPV of 94.9{\%}. Reasons for false-positive findings include collateralization of flow in the presence of proximal ICA stenosis and prestenotic to stenotic MCA velocity ratios of 1:≤2. Conclusion. TCD is both sensitive and specific in identifying ≥50{\%} intracranial arterial stenosis. A MFV threshold cutoff of 100 cm/s has an optimal sensitivity and specificity trade-off for ≥50{\%} MCA stenosis. To help avoid false-positive results, a prestenotic to stenotic MCA velocity ratio of 1:≥2 should be used in addition to the MFV threshold.",
author = "Felberg, {Robert A.} and Ioannis Christou and Demchuk, {Andrew M.} and Marc Malkoff and Andrei Alexandrov",
year = "2002",
month = "1",
day = "1",
doi = "10.1111/j.1552-6569.2002.tb00083.x",
language = "English (US)",
volume = "12",
pages = "9--14",
journal = "Journal of Neuroimaging",
issn = "1051-2284",
publisher = "Wiley-Blackwell",
number = "1",

}

TY - JOUR

T1 - Screening for intracranial stenosis with transcranial doppler

T2 - The accuracy of mean flow velocity thresholds

AU - Felberg, Robert A.

AU - Christou, Ioannis

AU - Demchuk, Andrew M.

AU - Malkoff, Marc

AU - Alexandrov, Andrei

PY - 2002/1/1

Y1 - 2002/1/1

N2 - Background. Patients with 50% intracranial arterial stenosis may require more intensive therapies for stroke prevention. Transcranial Doppler (TCD) is a convenient noninvasive screen for intracranial stenosis. The accuracy of different mean flow velocity (MFV) thresholds for determining the degree of stenosis remains uncertain. Methods. The authors prospectively compared the accuracy of TCD criteria and MFV thresholds to magnetic resonance, computed tomography, and digital subtraction angiography in patients with symptoms of recent or remote stroke or transient ischemic attack. Stenosis on angiography was measured as 0%, <50%, or ≥50% diameter reduction. Results. Of 136 consecutive patients, 33 (24%) had distal internal carotid artery (ICA), middle cerebral artery (MCA), posterior cerebral artery, or basilar artery stenosis on angiography (14 patients [10%] were excluded due to incomplete TCD examinations, mainly from a lack of temporal windows). TCD showed 31 true-positive, 9 false-positive, 2 false-negative, and 94 true-negative studies. For all vessels, TCD had a sensitivity of 93.9% (confidence interval [CI] = 89%-98%), a specificity of 91.2% (Cl = 87%-96%), a positive predictive value (PPV) of 77.5%, and a negative predictive value (NPV) of 97.9%. The trade-off in sensitivity and specificity for MCA MFV thresholds was as follows: MFV≥ 80 cm/s had a sensitivity of 100%, a specificity of 96.9% (Cl = 94%-99%), a PPV of 84%, and an NPV of 100%. MFV ≥ 100 cm/s had a sensitivity of 100%, a specificity of 97.9% (Cl = 96%-99%), a PPV of 88.8%, and an NPV of 94.9%. MFV≥ 120 cm/s had a sensitivity of 68.7% (Cl = 61%-78%), a specificity of 100%, a PPV of 100%, and an NPV of 94.9%. Reasons for false-positive findings include collateralization of flow in the presence of proximal ICA stenosis and prestenotic to stenotic MCA velocity ratios of 1:≤2. Conclusion. TCD is both sensitive and specific in identifying ≥50% intracranial arterial stenosis. A MFV threshold cutoff of 100 cm/s has an optimal sensitivity and specificity trade-off for ≥50% MCA stenosis. To help avoid false-positive results, a prestenotic to stenotic MCA velocity ratio of 1:≥2 should be used in addition to the MFV threshold.

AB - Background. Patients with 50% intracranial arterial stenosis may require more intensive therapies for stroke prevention. Transcranial Doppler (TCD) is a convenient noninvasive screen for intracranial stenosis. The accuracy of different mean flow velocity (MFV) thresholds for determining the degree of stenosis remains uncertain. Methods. The authors prospectively compared the accuracy of TCD criteria and MFV thresholds to magnetic resonance, computed tomography, and digital subtraction angiography in patients with symptoms of recent or remote stroke or transient ischemic attack. Stenosis on angiography was measured as 0%, <50%, or ≥50% diameter reduction. Results. Of 136 consecutive patients, 33 (24%) had distal internal carotid artery (ICA), middle cerebral artery (MCA), posterior cerebral artery, or basilar artery stenosis on angiography (14 patients [10%] were excluded due to incomplete TCD examinations, mainly from a lack of temporal windows). TCD showed 31 true-positive, 9 false-positive, 2 false-negative, and 94 true-negative studies. For all vessels, TCD had a sensitivity of 93.9% (confidence interval [CI] = 89%-98%), a specificity of 91.2% (Cl = 87%-96%), a positive predictive value (PPV) of 77.5%, and a negative predictive value (NPV) of 97.9%. The trade-off in sensitivity and specificity for MCA MFV thresholds was as follows: MFV≥ 80 cm/s had a sensitivity of 100%, a specificity of 96.9% (Cl = 94%-99%), a PPV of 84%, and an NPV of 100%. MFV ≥ 100 cm/s had a sensitivity of 100%, a specificity of 97.9% (Cl = 96%-99%), a PPV of 88.8%, and an NPV of 94.9%. MFV≥ 120 cm/s had a sensitivity of 68.7% (Cl = 61%-78%), a specificity of 100%, a PPV of 100%, and an NPV of 94.9%. Reasons for false-positive findings include collateralization of flow in the presence of proximal ICA stenosis and prestenotic to stenotic MCA velocity ratios of 1:≤2. Conclusion. TCD is both sensitive and specific in identifying ≥50% intracranial arterial stenosis. A MFV threshold cutoff of 100 cm/s has an optimal sensitivity and specificity trade-off for ≥50% MCA stenosis. To help avoid false-positive results, a prestenotic to stenotic MCA velocity ratio of 1:≥2 should be used in addition to the MFV threshold.

UR - http://www.scopus.com/inward/record.url?scp=0036140744&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036140744&partnerID=8YFLogxK

U2 - 10.1111/j.1552-6569.2002.tb00083.x

DO - 10.1111/j.1552-6569.2002.tb00083.x

M3 - Article

VL - 12

SP - 9

EP - 14

JO - Journal of Neuroimaging

JF - Journal of Neuroimaging

SN - 1051-2284

IS - 1

ER -