J Stroke Cerebrovasc Dis
1992;2:209-212
© 1992 National Stroke Association
Identification of Stenosis of the Opercular Segment of the Middle Cerebral Artery Trunk by Transcranial Color Flow Duplex Doppler },2Jesse Weinberger, M.D., 2Deborah R. Horowitz, M.D., and 3Michael Sacher, M.D.
Transcranial color flow duplex Doppler sonographywas able to identify a stenosis of the middle cerebral artery documented by angiography to be just proximal to the start of the sylvian triangle in a 50-year-old woman with progressive aphasia. The lesion was too distal to be detected by traditional transcranial Doppler sonography. Transverse and longitudinal color flow images of the opercular segment of the middle cerebral artery are shown with identification of the branches of the middle cerebral artery trifurcation. Key Words: Transcranial color flow Doppler sonography-Middle cerebral artery-Stenosis.
Transcranial Doppler sonography of the intracranial arteries was developed by Aaslid in 1982 (1) and has been documented to be useful in detecting stenosis of the M1 and M2 segments of the middle cerebral artery trunk (2). We report a case of a 50year-old woman with progressive aphasia who had angiographically documented stenosis of the distal M2 segment just proximal to the origin of the sylvian triangle. The lesion was located too far distally to be detected by indirect transcranial Doppler sonography performed both before and after the anglographic demonstration of the lesion. Transcranial color flow Doppler sonography was able to demonstrate the origin of the sylvian portion of the middle cerebral artery, and duplex-pulsed Doppler confirmed high-velocity turbulent flow originating from the middle cerebral stenosis.
From the lDivision of Neurology, North General Hospital, and Departments of 2Neurology and 3Radiology, The Mount Sinai School of Medicine, New York, NY, U.S.A. Address correspondence and reprint requests to Dr. ]. Weinberger at Department of Neurology, Box 1139, The Mount Sinai School of Medicine, 1 Gustav Levy Place, New York, NY 10029, U.S.A.
Case Report A 50-year-old woman was admitted to the Acute Stroke Unit at The Mount Sinai Hospital because of progressive difficulty expressing herself. Two days previously, she had suddenly lost the ability to calculate at her job. Seven months previously, she had had a mild stroke with word-finding difficulty, right facial droop, and slight drift of the right arm, which resolved almost completely. A patent foramen ovale was documented by transesophageal echocardiography with contrast enhancement, and she had been started on warfarin. After 6 months of anticoagulation with warfarin, aspirin was substituted. The recurrent event occurred 1 month after aspirin therapy was initiated. On neurological examination, the patient had fluent but halting speech with word-finding difficulty and occasional paraphasic errors similar to her initial event. She had a mild right facial droop and drift of the right arm. Computed tomography of the brain demonstrated a left parietal infarction. The patient was started on heparin anticoagulation with resolution of her neurological deficits except for difficulty with calculations and occasional word-finding deficits.
J STROKE CEREBROVASC DIS, VOL. 2, NO.4,
1992
209
t. WEINBERGERIT AL The patient was brought to North General Hospital to undergo color flow duplex transcranial Doppler sonography to identify the middle cerebral artery stenosis so that it could be followed noninvasively.
Materials and Methods
Figure 1. Direct intra-arterial angiograplly of leftmiddle cerebral artery stenosis (arrow) in the patient described uiith progressive aphasia .
Carotid duplex ultrasonography and transcranial Doppler (EME TC2-64B, Carolina Medical Electronics, Mountain View, CA) were normal. Because of the recurrent and progressive nature of the patient's stroke, cerebral angiography was performed. A moderate stenosis of the distal M2 segment of the middle cerebral artery was identified (Fig. 1).
Color flow transcranial duplex Doppler sonography was performed with an Acuson 128 XP/10 V219 2.25-MHz pulsed Doppler sector transducer (Acuson, Mountain View, CA) using 1.28 W/cm 2 power and 125-Hz wall filter. The probe was placed over the preauricular region and rotated until the bifurcation of the internal carotid artery into the middle and anterior cerebral arteries could be visualized. Pulsed Doppler signals were recorded at various depths along the course of the anterior and middle cerebral arteries and waveforms displayed with a fast Fourier transform analysis.
Results The bifurcation of the intracerebral internal carotid artery into the anterior and middle cerebral arteries could be visualized at a depth of 65 mm in both the asymptomatic right and symptomatic left cerebral hemisphere (Fig. 2). Flow velocity in the proximal left middle cerebral artery was slightly '
Figure 2. Color flowduplexDoppler images oftileinternal carotid arterybifurcation, anterior cerebral artery, middle cerebral arterytrunk, andopercular middle cerebral arteryin transverse view fromthenonnalrigllt andabnormallejt cerebral hemispheres in the patient described Witll progressive aphasia . Tilesolid whitearrow points tothe M1 segment oftJle middle cerebral arteryfrom65-I/Iln to55-mmdepth toith' ti,e in/emalcarotid totherightofthearrow (illrigllt hemisphere only)andtheanterior cerebral arteryflowillgawayfrom thearrow. Thearrowhead points to the opercular division of the middle cerebral artery visualized in the transverse view at 30-35-mm depth. 210
/ STROKE CEREBROVASCDIS, VOL. 2, NO.4, 1992
MCA STENOSISIDENTIFIED BY COLOR FLOW TCD
Figure 3. Spectral analysis ofpulsedwaveduplexDoppler signals from theproximal middlecerebral arteries andopercular middlecerebral arteries fromthenormal riglzt andabnonnalleftcerebral hemispheres ofthepatientdescribed withprogressiveaphasia. Peak flowvelocities in the proximal leftmiddle cerebral artery (C) arelowerilion 011 the right (D), but botharetouhin normallimits, and there is no reduction in diastolic runoff. Peak flowvelocitiesin theopercularportioll ofthemiddle cerebral arteryat 33 mmareelevated on theleft(A)compared tothe right(B) with spreadofhigh-velocityflowintodiastole. Flowis beingmeasuredilla transverse projection of theascendingopercular port ion ofthemiddlecerebral arteryandis biphasic onboththenormaland abnormal sides. TIle location ofthemeasurement isjustdistal tothestenosis seen on allgiography.
lower than the right, but both were in the normal range, and there was no attenuation of diastolic runoff in the waveform on the left (Fig. 3). The distal middle cerebral trunk, as it approached the opercular division, could be visualized in the
same plane at a depth of 33 mm in both the asymptomatic right and symptomatic left cerebral hemisphere (Fig. 2). Although the color pattern on the left appeared to be irregular compared to the right, it could not definitely be determined just by visual-
c
Figure 4. Demonstration oftheopercular branches ofthe middlecerebral arteryin alongitudinalprojection withatleast two branches seen simultaneously (B) from30-11l1n to35-mmdepth. TIle relationship tothe M1 segment is shoum(A) from55-11l1n to 65-m11/ depth. TIle recording is madefrom a normal subject 0.W.). Flow velocities (e) are recorded from the large bran cn of the middle cerebral artery (D).
JSTROKECEREBROVASCDIS, VOL.2, NO.4, 1992 211
i WEINBERGERETAL ization that this was the area of stenosis. However, by insonation with the pulsed Doppler in this region, there was increased flow velocity with spread of high-velocity flow into diastole on the left in the region corresponding to the stenosis seen on angiography (Fig. 3). Both flow velocity waveforms were biphasic because the origin of the opercular portion of the middle cerebral artery was being insonated in a transverse projection, and flow both toward and away from the probe was being detected. At least two branches of the middle cerebral artery can also be seen in the longitudinal view of the opercular portion of the middle cerebral artery. The accompanying longitudinal view is from a normal volunteer (l.W.) (Fig. 4). Flow in the longitudinal view of an opercular branch of the middle cerebral artery is monophasic, away from the probe (Fig. 4).
Discussion Aaslid was the first to insonate flow from intracranial arteries at the base of the brain by Doppler ultrasonography using a technique that demonstrated velocity waveforms but did not show corresponding images of the vessels (1). Ringelstein was able to demonstrate angiographical1y documented stenoses of the middle cerebral artery employing this technique (2). Color coding of these transcranial Doppler signals has been employed to construct three-dimensional flow maps (3). This technique has enhanced identification of middle cerebral artery stenosis but is arduous and timeconsuming and does not provide direct visualization of the vessel being insonated (2). Visualization of the vessels of the base of the brain by transcranial color-coded duplex Doppler ultrasonography has been achieved by several authors (4-8). In addition to imaging Doppler flow in real time, the wal1s of the vessels can be imaged (7) and some brain structures identified (5). This technique has the advantage of imaging the vessel directly, providing precise anatomical localization of the origin of duplex-pulsed Doppler signals from the middle cerebral, anterior cerebral, and internal carotid arteries. The present case corroborates with angiography that flow insonated at 33-mm depth, 30mm distal to the internal carotid bifurcation, represents flow in the opercular portion of the middle cerebral artery. Flow in the middle cerebral artery can sometimes be obtained at 35-mm depth by indirect transcranial Doppler ultrasonography (2), but not very often
212
] STROKECEREBROVASCDIS, VOL.2, NO.4, 1992
because of the change in the angle of insonation. It was not possible in the present case .
Transcranial color flow duplex Doppler sonography can also be employed to measure flow in opercular branches of the middle cerebral artery along the sylvian fissure. The anatomical localization of this portion of the vessel becomes clear because of the curvature of th e vessel away from the middle cerebral trunk and the identification of multiple branches. Detecting flow in branches of the middle cerebral artery was not possible previously (2). This technique may be particularly useful in patients with embolic occlusive disease of the distal middle cerebral artery, which may be the etiology in the current patient, who had a history of patent foramen ovale, With the advent of magnetic resonance imaging angiography, the role of transcranial Doppler sonography has been brought into question. However, it is not clear that magnetic resonance imaging angiography would be able to detect a stenosis of the moderate degree seen in the present case . Transcranial color duplex Doppler sonography also has the advantage of delineating flow in real time for physiological measurements under a variety of conditions.
References 1. Aaslid R, Markwalder T-M, Nornes H. Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries. ] Neurosurg 1982; 52:769-74. 2. Ringelstein EB. A practical gu ide to transcranial Doppler sonography. In: Weinberger J, ed. Noninvasive imagingofcerebrovascular disea se. New York: Uss,1989: 75-122. 3. Aaslid R. Transcranial Doppler examination technique. In: AasIid R,ed. Transcranial Dopplersonography. Wein: Springer 1986:39-59. 4. Schoning M, Grunert D, Stier B. TranscranieIIe duplexconographie durch den intakten Knochen: Ein nues diagnotisches Verfahren. Outrascha1l1989;10:66-71. 5. Bogdahn V, Becker G, Winkler J. Tran scranial colorcod ed real-time sonography in adults. Stroke 1990; 21:1680-8. 6. Tsuchiya T, Yasaka M, Yamaguchi T. Imaging of the basal cerebral arteries and measurement of blood velocity in adults by using transcranial real-time color flow Doppler sonography. A]NR 1991;12:497-502. 7. Montefusco-von Kleist CM, Rhodes BA. Duplex ultrasonographic insonation and visualization of intracerebral arteries. Angiology 1991;42:812-8 . 8. Hashimoto BE, Hallrick CWo New method of adult transcranial Doppler. ] Ultra sound Med 1991;10:34953.
1992;2:209-212
© 1992 National Stroke Association
Identification of Stenosis of the Opercular Segment of the Middle Cerebral Artery Trunk by Transcranial Color Flow Duplex Doppler },2Jesse Weinberger, M.D., 2Deborah R. Horowitz, M.D., and 3Michael Sacher, M.D.
Transcranial color flow duplex Doppler sonographywas able to identify a stenosis of the middle cerebral artery documented by angiography to be just proximal to the start of the sylvian triangle in a 50-year-old woman with progressive aphasia. The lesion was too distal to be detected by traditional transcranial Doppler sonography. Transverse and longitudinal color flow images of the opercular segment of the middle cerebral artery are shown with identification of the branches of the middle cerebral artery trifurcation. Key Words: Transcranial color flow Doppler sonography-Middle cerebral artery-Stenosis.
Transcranial Doppler sonography of the intracranial arteries was developed by Aaslid in 1982 (1) and has been documented to be useful in detecting stenosis of the M1 and M2 segments of the middle cerebral artery trunk (2). We report a case of a 50year-old woman with progressive aphasia who had angiographically documented stenosis of the distal M2 segment just proximal to the origin of the sylvian triangle. The lesion was located too far distally to be detected by indirect transcranial Doppler sonography performed both before and after the anglographic demonstration of the lesion. Transcranial color flow Doppler sonography was able to demonstrate the origin of the sylvian portion of the middle cerebral artery, and duplex-pulsed Doppler confirmed high-velocity turbulent flow originating from the middle cerebral stenosis.
From the lDivision of Neurology, North General Hospital, and Departments of 2Neurology and 3Radiology, The Mount Sinai School of Medicine, New York, NY, U.S.A. Address correspondence and reprint requests to Dr. ]. Weinberger at Department of Neurology, Box 1139, The Mount Sinai School of Medicine, 1 Gustav Levy Place, New York, NY 10029, U.S.A.
Case Report A 50-year-old woman was admitted to the Acute Stroke Unit at The Mount Sinai Hospital because of progressive difficulty expressing herself. Two days previously, she had suddenly lost the ability to calculate at her job. Seven months previously, she had had a mild stroke with word-finding difficulty, right facial droop, and slight drift of the right arm, which resolved almost completely. A patent foramen ovale was documented by transesophageal echocardiography with contrast enhancement, and she had been started on warfarin. After 6 months of anticoagulation with warfarin, aspirin was substituted. The recurrent event occurred 1 month after aspirin therapy was initiated. On neurological examination, the patient had fluent but halting speech with word-finding difficulty and occasional paraphasic errors similar to her initial event. She had a mild right facial droop and drift of the right arm. Computed tomography of the brain demonstrated a left parietal infarction. The patient was started on heparin anticoagulation with resolution of her neurological deficits except for difficulty with calculations and occasional word-finding deficits.
J STROKE CEREBROVASC DIS, VOL. 2, NO.4,
1992
209
t. WEINBERGERIT AL The patient was brought to North General Hospital to undergo color flow duplex transcranial Doppler sonography to identify the middle cerebral artery stenosis so that it could be followed noninvasively.
Materials and Methods
Figure 1. Direct intra-arterial angiograplly of leftmiddle cerebral artery stenosis (arrow) in the patient described uiith progressive aphasia .
Carotid duplex ultrasonography and transcranial Doppler (EME TC2-64B, Carolina Medical Electronics, Mountain View, CA) were normal. Because of the recurrent and progressive nature of the patient's stroke, cerebral angiography was performed. A moderate stenosis of the distal M2 segment of the middle cerebral artery was identified (Fig. 1).
Color flow transcranial duplex Doppler sonography was performed with an Acuson 128 XP/10 V219 2.25-MHz pulsed Doppler sector transducer (Acuson, Mountain View, CA) using 1.28 W/cm 2 power and 125-Hz wall filter. The probe was placed over the preauricular region and rotated until the bifurcation of the internal carotid artery into the middle and anterior cerebral arteries could be visualized. Pulsed Doppler signals were recorded at various depths along the course of the anterior and middle cerebral arteries and waveforms displayed with a fast Fourier transform analysis.
Results The bifurcation of the intracerebral internal carotid artery into the anterior and middle cerebral arteries could be visualized at a depth of 65 mm in both the asymptomatic right and symptomatic left cerebral hemisphere (Fig. 2). Flow velocity in the proximal left middle cerebral artery was slightly '
Figure 2. Color flowduplexDoppler images oftileinternal carotid arterybifurcation, anterior cerebral artery, middle cerebral arterytrunk, andopercular middle cerebral arteryin transverse view fromthenonnalrigllt andabnormallejt cerebral hemispheres in the patient described Witll progressive aphasia . Tilesolid whitearrow points tothe M1 segment oftJle middle cerebral arteryfrom65-I/Iln to55-mmdepth toith' ti,e in/emalcarotid totherightofthearrow (illrigllt hemisphere only)andtheanterior cerebral arteryflowillgawayfrom thearrow. Thearrowhead points to the opercular division of the middle cerebral artery visualized in the transverse view at 30-35-mm depth. 210
/ STROKE CEREBROVASCDIS, VOL. 2, NO.4, 1992
MCA STENOSISIDENTIFIED BY COLOR FLOW TCD
Figure 3. Spectral analysis ofpulsedwaveduplexDoppler signals from theproximal middlecerebral arteries andopercular middlecerebral arteries fromthenormal riglzt andabnonnalleftcerebral hemispheres ofthepatientdescribed withprogressiveaphasia. Peak flowvelocities in the proximal leftmiddle cerebral artery (C) arelowerilion 011 the right (D), but botharetouhin normallimits, and there is no reduction in diastolic runoff. Peak flowvelocitiesin theopercularportioll ofthemiddle cerebral arteryat 33 mmareelevated on theleft(A)compared tothe right(B) with spreadofhigh-velocityflowintodiastole. Flowis beingmeasuredilla transverse projection of theascendingopercular port ion ofthemiddlecerebral arteryandis biphasic onboththenormaland abnormal sides. TIle location ofthemeasurement isjustdistal tothestenosis seen on allgiography.
lower than the right, but both were in the normal range, and there was no attenuation of diastolic runoff in the waveform on the left (Fig. 3). The distal middle cerebral trunk, as it approached the opercular division, could be visualized in the
same plane at a depth of 33 mm in both the asymptomatic right and symptomatic left cerebral hemisphere (Fig. 2). Although the color pattern on the left appeared to be irregular compared to the right, it could not definitely be determined just by visual-
c
Figure 4. Demonstration oftheopercular branches ofthe middlecerebral arteryin alongitudinalprojection withatleast two branches seen simultaneously (B) from30-11l1n to35-mmdepth. TIle relationship tothe M1 segment is shoum(A) from55-11l1n to 65-m11/ depth. TIle recording is madefrom a normal subject 0.W.). Flow velocities (e) are recorded from the large bran cn of the middle cerebral artery (D).
JSTROKECEREBROVASCDIS, VOL.2, NO.4, 1992 211
i WEINBERGERETAL ization that this was the area of stenosis. However, by insonation with the pulsed Doppler in this region, there was increased flow velocity with spread of high-velocity flow into diastole on the left in the region corresponding to the stenosis seen on angiography (Fig. 3). Both flow velocity waveforms were biphasic because the origin of the opercular portion of the middle cerebral artery was being insonated in a transverse projection, and flow both toward and away from the probe was being detected. At least two branches of the middle cerebral artery can also be seen in the longitudinal view of the opercular portion of the middle cerebral artery. The accompanying longitudinal view is from a normal volunteer (l.W.) (Fig. 4). Flow in the longitudinal view of an opercular branch of the middle cerebral artery is monophasic, away from the probe (Fig. 4).
Discussion Aaslid was the first to insonate flow from intracranial arteries at the base of the brain by Doppler ultrasonography using a technique that demonstrated velocity waveforms but did not show corresponding images of the vessels (1). Ringelstein was able to demonstrate angiographical1y documented stenoses of the middle cerebral artery employing this technique (2). Color coding of these transcranial Doppler signals has been employed to construct three-dimensional flow maps (3). This technique has enhanced identification of middle cerebral artery stenosis but is arduous and timeconsuming and does not provide direct visualization of the vessel being insonated (2). Visualization of the vessels of the base of the brain by transcranial color-coded duplex Doppler ultrasonography has been achieved by several authors (4-8). In addition to imaging Doppler flow in real time, the wal1s of the vessels can be imaged (7) and some brain structures identified (5). This technique has the advantage of imaging the vessel directly, providing precise anatomical localization of the origin of duplex-pulsed Doppler signals from the middle cerebral, anterior cerebral, and internal carotid arteries. The present case corroborates with angiography that flow insonated at 33-mm depth, 30mm distal to the internal carotid bifurcation, represents flow in the opercular portion of the middle cerebral artery. Flow in the middle cerebral artery can sometimes be obtained at 35-mm depth by indirect transcranial Doppler ultrasonography (2), but not very often
212
] STROKECEREBROVASCDIS, VOL.2, NO.4, 1992
because of the change in the angle of insonation. It was not possible in the present case .
Transcranial color flow duplex Doppler sonography can also be employed to measure flow in opercular branches of the middle cerebral artery along the sylvian fissure. The anatomical localization of this portion of the vessel becomes clear because of the curvature of th e vessel away from the middle cerebral trunk and the identification of multiple branches. Detecting flow in branches of the middle cerebral artery was not possible previously (2). This technique may be particularly useful in patients with embolic occlusive disease of the distal middle cerebral artery, which may be the etiology in the current patient, who had a history of patent foramen ovale, With the advent of magnetic resonance imaging angiography, the role of transcranial Doppler sonography has been brought into question. However, it is not clear that magnetic resonance imaging angiography would be able to detect a stenosis of the moderate degree seen in the present case . Transcranial color duplex Doppler sonography also has the advantage of delineating flow in real time for physiological measurements under a variety of conditions.
References 1. Aaslid R, Markwalder T-M, Nornes H. Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries. ] Neurosurg 1982; 52:769-74. 2. Ringelstein EB. A practical gu ide to transcranial Doppler sonography. In: Weinberger J, ed. Noninvasive imagingofcerebrovascular disea se. New York: Uss,1989: 75-122. 3. Aaslid R. Transcranial Doppler examination technique. In: AasIid R,ed. Transcranial Dopplersonography. Wein: Springer 1986:39-59. 4. Schoning M, Grunert D, Stier B. TranscranieIIe duplexconographie durch den intakten Knochen: Ein nues diagnotisches Verfahren. Outrascha1l1989;10:66-71. 5. Bogdahn V, Becker G, Winkler J. Tran scranial colorcod ed real-time sonography in adults. Stroke 1990; 21:1680-8. 6. Tsuchiya T, Yasaka M, Yamaguchi T. Imaging of the basal cerebral arteries and measurement of blood velocity in adults by using transcranial real-time color flow Doppler sonography. A]NR 1991;12:497-502. 7. Montefusco-von Kleist CM, Rhodes BA. Duplex ultrasonographic insonation and visualization of intracerebral arteries. Angiology 1991;42:812-8 . 8. Hashimoto BE, Hallrick CWo New method of adult transcranial Doppler. ] Ultra sound Med 1991;10:34953.
