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Neuroradiology 16, 145-146 (1978)
© by Springer-Verlag1978
D o p p l e r U l t r a s o u n d E v a l u a t i o n o f E x t r a c r a n i a l C e r e b r o v a s c u l a r Disease W. Zwiebel, P. Turski, C. Strother, A. Crummy, J. Sackett, and P. Barriga University of Wisconsin Hospitals, Madison, Wisconsin, USA
Summary. Carotid Doppler examination was compared with arteriographic findings in 125 patients. The results demonstrated exact correlation in 87% of vessels studied. Clinically significant errors occurred at a rate of 4.5%. Clinically insignificant errors (8.5%) were usually the result of wall disease being mistaken for nonhemodynamically significant stenosis.
Doppler ultrasound provides an accurate, noninvasive method for evaluation of extracranial cerebrovascular disease. Hass et al. [3] estimated that 40% of patients with ischemic stroke had segmental arterial occlusions of the extracranial carotid system. Surgically accessible lesions were present in 75% of these patients. Doppler evaluation of the carotid vessels was first described by Spencer, Reid, and Thomas [5, 6]. To determine the accuracy of this method, the arteriographic findings were compared with Doppler results in 125 patients examined at the University of Wisconsin Hospitals.
Method The cervical carotid artery is mapped by a sharply focused, continuous-wave, Doppler ultrasound probe connected to a mechanical scanning arm. A two-dimensional image of the artery being examined is generated and photographed. Doppler audio frequency signals are simultaneously recorded on tape. Vessel caliber variations and velocity of blood flow are reflected in alterations of the audio signal. The direction of ophthalmic artery flow is determined by placing the probe over the closed eye. Results Doppler evaluation was compared with arteriography in 125 patients (250 carotid bifurcations). Sixty patients had symptoms or signs of cerebral ischemia without bruits. Asymptomatic bruits were present in 33 patients
and 30 patients had both symptoms and bruits. Two patients were examined for other reasons. The common carotid, and internal and external carotids were evaluated separately. The evaluations were categorized as normal, evidence of wall disease, nonhemodynamicaUy significant stenosis, hemodynamicaUy significant stenosis, or occluded. Exact correlation occurred in 218/250 bifurcations or 87%. Overestimates (15) and underestimates (18) occurred with similar frequency. In only 11/250 (4.5%) bifurcations was the magnitude of error such that inappropriate therapy would have been undertaken had the Doppler findings been considered definitive. The clinically insignificant errors 22/250 (8.5%) were usually the result of wall disease being mistaken for a nonhemodynamically significant stenosis (Table 1).
Discussion These results indicate that Doppler examination can provide an accurate assessment Of extracranial occlusive disease and support the findings of Barnes et al. [2]. Wall disease is not as accurately detected as stenosis. Audio signal changes are the most sensitive aspect of the examination. Turbulence and coarse tones are associated with nonobstmcting plaques. High frequency Doppler signals are associated with stenosis and are usuTable 1. Doppler correlation with angiography
Number Percent Overestimated lesions Underestimated lesions
Exact ClinicallysigCorrelation nificant error
Clinicallyinsignificant error
218/250 87%
22/250 8.5% 10
11/250 4.5% 5 6
12
0028-3940/78/0016/0145/$ 01.00
146 ally very characteristic. The higher the frequency the greater is the stenosis. Calcified plaques complicate the examination by producing nonsounding areas [1]. The images o f the carotid bifurcation are relatively gross but are very useful in locating the site of an abnormal audio frequency. Eighteen patients had reversed ophthalmic artery flow determined by pulse trace analysis over the eye. By arteriography, 13 o f these patients had complete occlusion o f the internal or c o m m o n carotid and four had hemodynamically significant sten0sis. Thus, reversed flow in the ophthalmic artery is highly suggestive of significant disease in the cervical vessels [4]. Doppler evaluation has proved useful in evaluating asymptomatic bruits. If the lesion is nonhemodynamically significant, it may be followed up in order to determine if there is progression and at what rate. Postendarterectomy evaluation determines flow and patency and assesses the possibility o f recurrence of stenosis. Patients with TIA's are more expediently evaluated with arteriography.
W. Zwiebel et al.: Doppler Evaluation of Vascular Disease
References 1. Baker, W.H., Barnes, R.W.: The cerebrovascular Doppler examination in patients with non-hemispheric symptoms. Ann. Surg. 186,190 (1977) 2. Barnes, R.W., Bone, G.E., et al.: Non-invasive ultrasonic carotid angiography: prospective Validation by contrast arteriography. Surgery 80, 328 (1976) 3. Hass, W.K., Field, S.W., North, P.R., et al.: Joint study of extracranial arterial occlusion II. Arteriography: techniques, sites and complications. JAMA 203,961 (1968) 4. Moore, W.S., Bean, B., Burton, R.: The use ofophthalmosonometry in the diagnosis of carotid stenosis. Surgery 82, 107 (1977) 5. Reid, J.M., Spencer, M.P.: Ultrasonic Doppler technique for imaging blood vessels. Science 176, 1235 (1972) 6. Thomas, G.I., Spencer, M.P., et al.: Non-invasive carotid bifurcation mapping. Its relation to carotid surgery. Am. J. Surg. 128,168 (1974) W. Zwiebel, MD Department of Radiology 1300 University Avenue Madison, W153706, USA
Neuroradiology 16, 145-146 (1978)
© by Springer-Verlag1978
D o p p l e r U l t r a s o u n d E v a l u a t i o n o f E x t r a c r a n i a l C e r e b r o v a s c u l a r Disease W. Zwiebel, P. Turski, C. Strother, A. Crummy, J. Sackett, and P. Barriga University of Wisconsin Hospitals, Madison, Wisconsin, USA
Summary. Carotid Doppler examination was compared with arteriographic findings in 125 patients. The results demonstrated exact correlation in 87% of vessels studied. Clinically significant errors occurred at a rate of 4.5%. Clinically insignificant errors (8.5%) were usually the result of wall disease being mistaken for nonhemodynamically significant stenosis.
Doppler ultrasound provides an accurate, noninvasive method for evaluation of extracranial cerebrovascular disease. Hass et al. [3] estimated that 40% of patients with ischemic stroke had segmental arterial occlusions of the extracranial carotid system. Surgically accessible lesions were present in 75% of these patients. Doppler evaluation of the carotid vessels was first described by Spencer, Reid, and Thomas [5, 6]. To determine the accuracy of this method, the arteriographic findings were compared with Doppler results in 125 patients examined at the University of Wisconsin Hospitals.
Method The cervical carotid artery is mapped by a sharply focused, continuous-wave, Doppler ultrasound probe connected to a mechanical scanning arm. A two-dimensional image of the artery being examined is generated and photographed. Doppler audio frequency signals are simultaneously recorded on tape. Vessel caliber variations and velocity of blood flow are reflected in alterations of the audio signal. The direction of ophthalmic artery flow is determined by placing the probe over the closed eye. Results Doppler evaluation was compared with arteriography in 125 patients (250 carotid bifurcations). Sixty patients had symptoms or signs of cerebral ischemia without bruits. Asymptomatic bruits were present in 33 patients
and 30 patients had both symptoms and bruits. Two patients were examined for other reasons. The common carotid, and internal and external carotids were evaluated separately. The evaluations were categorized as normal, evidence of wall disease, nonhemodynamicaUy significant stenosis, hemodynamicaUy significant stenosis, or occluded. Exact correlation occurred in 218/250 bifurcations or 87%. Overestimates (15) and underestimates (18) occurred with similar frequency. In only 11/250 (4.5%) bifurcations was the magnitude of error such that inappropriate therapy would have been undertaken had the Doppler findings been considered definitive. The clinically insignificant errors 22/250 (8.5%) were usually the result of wall disease being mistaken for a nonhemodynamically significant stenosis (Table 1).
Discussion These results indicate that Doppler examination can provide an accurate assessment Of extracranial occlusive disease and support the findings of Barnes et al. [2]. Wall disease is not as accurately detected as stenosis. Audio signal changes are the most sensitive aspect of the examination. Turbulence and coarse tones are associated with nonobstmcting plaques. High frequency Doppler signals are associated with stenosis and are usuTable 1. Doppler correlation with angiography
Number Percent Overestimated lesions Underestimated lesions
Exact ClinicallysigCorrelation nificant error
Clinicallyinsignificant error
218/250 87%
22/250 8.5% 10
11/250 4.5% 5 6
12
0028-3940/78/0016/0145/$ 01.00
146 ally very characteristic. The higher the frequency the greater is the stenosis. Calcified plaques complicate the examination by producing nonsounding areas [1]. The images o f the carotid bifurcation are relatively gross but are very useful in locating the site of an abnormal audio frequency. Eighteen patients had reversed ophthalmic artery flow determined by pulse trace analysis over the eye. By arteriography, 13 o f these patients had complete occlusion o f the internal or c o m m o n carotid and four had hemodynamically significant sten0sis. Thus, reversed flow in the ophthalmic artery is highly suggestive of significant disease in the cervical vessels [4]. Doppler evaluation has proved useful in evaluating asymptomatic bruits. If the lesion is nonhemodynamically significant, it may be followed up in order to determine if there is progression and at what rate. Postendarterectomy evaluation determines flow and patency and assesses the possibility o f recurrence of stenosis. Patients with TIA's are more expediently evaluated with arteriography.
W. Zwiebel et al.: Doppler Evaluation of Vascular Disease
References 1. Baker, W.H., Barnes, R.W.: The cerebrovascular Doppler examination in patients with non-hemispheric symptoms. Ann. Surg. 186,190 (1977) 2. Barnes, R.W., Bone, G.E., et al.: Non-invasive ultrasonic carotid angiography: prospective Validation by contrast arteriography. Surgery 80, 328 (1976) 3. Hass, W.K., Field, S.W., North, P.R., et al.: Joint study of extracranial arterial occlusion II. Arteriography: techniques, sites and complications. JAMA 203,961 (1968) 4. Moore, W.S., Bean, B., Burton, R.: The use ofophthalmosonometry in the diagnosis of carotid stenosis. Surgery 82, 107 (1977) 5. Reid, J.M., Spencer, M.P.: Ultrasonic Doppler technique for imaging blood vessels. Science 176, 1235 (1972) 6. Thomas, G.I., Spencer, M.P., et al.: Non-invasive carotid bifurcation mapping. Its relation to carotid surgery. Am. J. Surg. 128,168 (1974) W. Zwiebel, MD Department of Radiology 1300 University Avenue Madison, W153706, USA
