Stroke, Vol 24, 1922-1924, Copyright © 1993 by American Heart Association
DG Grosset, D Georgiadis, AW Kelman and KR Lees
BACKGROUND AND PURPOSE: The use of Doppler ultrasound to detect arterial
emboli has major implications for the classification and treatment of
stroke. Experimental studies indicate that embolic materials produce
different ultrasound signals, depending on their acoustic properties. To
examine the possibility of characterizing emboli of different sources in
the clinical setting, we compared the emboli signals of patients with
cardiac embolic sources with those of patients with signals of carotid
embolic sources. METHODS: Transcranial Doppler monitoring (30 minutes per
patient) of the middle cerebral arteries was performed in 80 patients with
prosthetic cardiac valves and 20 patients with internal carotid artery
stenosis. The signal power of emboli was calculated in relation to the
background Doppler signal. RESULTS: In patients who were embolizing from
prosthetic heart valves, the frequency of embolus signals was greater than
in patients with carotid stenosis who were embolizing (mean +/- SEM: 58.2
+/- 11 versus 8.2 +/- 3 signals per hour; P < .0001, two-sample t test),
and total signal power and duration also were higher (power, 2231 +/- 63
versus 455 +/- 109 power units; duration, 55.9 +/- 0.8 versus 29.9 +/- 1.4
milliseconds; both P < .001). The majority of emboli signals were seen
during cardiac systole, especially in patients with carotid stenosis (89%
in the first half of the cardiac cycle versus 72% in prosthetic valve
patients). In 19 patients with prosthetic valves, embolus signals were also
recorded from the anterior cerebral artery; the signal count was not
significantly different from the middle cerebral artery (43.2 +/- 12.5
versus 64.3 +/- 16 per hour), but anterior cerebral artery signals were of
higher power (3306 +/- 148 versus 2441 +/- 109 power units, P < .001).
CONCLUSIONS: There is promise of being able to distinguish emboli on the
basis of power measurements. Emboli of different sources (eg, carotid and
cardiac) appear to have different ultrasonic characteristics, which are
likely to be based on composition and size.
ARTICLES
Quantification of ultrasound emboli signals in patients with cardiac and carotid disease
Acute Stroke Unit, Western Infirmary, Glasgow, UK.
This article has been cited by other articles:
 |
|
 |
|
  S. Sarkar, S. Ghosh, S. K. Ghosh, and A. Collier Role of transcranial Doppler ultrasonography in stroke Postgrad. Med. J., November 1, 2007; 83(985): 683 - 689. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. S. Markus and M. Punter Can Transcranial Doppler Discriminate Between Solid and Gaseous Microemboli?: Assessment of a Dual-Frequency Transducer System Stroke, August 1, 2005; 36(8): 1731 - 1734. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. W. Baumgartner, A. Frick, C. Kremer, E. Oechslin, E. Russi, J. Turina, and D. Georgiadis Microembolic signal counts increase during hyperbaric exposure in patients with prosthetic heart valves J. Thorac. Cardiovasc. Surg., December 1, 2001; 122(6): 1142 - 1146. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Omae, O. Mayzel-Oreg, F. Li, C. H. Sotak, M. Fisher, and E. C. Haley Jr Inapparent Hemodynamic Insufficiency Exacerbates Ischemic Damage in a Rat Microembolic Stroke Model Editorial Comment Stroke, October 1, 2000; 31(10): 2494 - 2499. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Cullinane, G. Reid, R. Dittrich, Z. Kaposzta, R. Ackerstaff, V. Babikian, D. W. Droste, D. Grossett, M. Siebler, L. Valton, et al. Evaluation of New Online Automated Embolic Signal Detection Algorithm, Including Comparison With Panel of International Experts Stroke, June 1, 2000; 31(6): 1335 - 1341. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Markus, M. Cullinane, and G. Reid Improved Automated Detection of Embolic Signals Using a Novel Frequency Filtering Approach Stroke, August 1, 1999; 30(8): 1610 - 1615. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Geiser, M. Sturzenegger, U. Genewein, A. Haeberli, and J. H. Beer Mechanisms of Cerebrovascular Events as Assessed by Procoagulant Activity, Cerebral Microemboli, and Platelet Microparticles in Patients With Prosthetic Heart Valves Stroke, September 1, 1998; 29(9): 1770 - 1777. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Deklunder, M. Roussel, J.-L. Lecroart, A. Prat, and C. Gautier Microemboli in Cerebral Circulation and Alteration of Cognitive Abilities in Patients With Mechanical Prosthetic Heart Valves Stroke, September 1, 1998; 29(9): 1821 - 1826. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. L. Smith, D. H. Evans, P. R. F. Bell, and A. R. Naylor A Comparison of Four Methods for Distinguishing Doppler Signals From Gaseous and Particulate Emboli Stroke, June 1, 1998; 29(6): 1133 - 1138. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Georgiadis, A. Wenzel, H. R. Zerkowski, S. Zierz, and A. Lindner Automated Intraoperative Detection of Doppler Microembolic Signals Using the Bigate Approach Stroke, January 1, 1998; 29(1): 137 - 139. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Sliwka and D. Georgiadis Clinical Correlations of Doppler Microembolic Signals in Patients With Prosthetic Cardiac Valves : Analysis of 580 Cases Stroke, January 1, 1998; 29(1): 140 - 143. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Specker, A. Perniok, U. Brauckmann, M. Siebler, and M. Schneider Review : Detection of cerebral microemboli in APS-- Introducing a novel investigation method and implications of analogies with carotid artery disease Lupus, January 1, 1998; 7(2_suppl): S75 - S80. [Abstract] [PDF]
|
|
|
|
|
|
D. Georgiadis, A. Wenzel, D. Lehmann, A. Lindner, H.R. Zerkowski, S. Zierz, and M.P. Spencer Influence of Oxygen Ventilation on Doppler Microemboli Signals in Patients With Artificial Heart Valves Stroke, November 1, 1997; 28(11): 2189 - 2194. [Abstract] [Full Text]
|
|
|
|
|
|
H. S. Markus and J. Molloy Use of a Decibel Threshold in Detecting Doppler Embolic Signals Stroke, April 1, 1997; 28(4): 692 - 695. [Abstract] [Full Text]
|
|
|
|
|
|
M. Kaps, J. Hansen, M. Weiher, K. Tiffert, I. Kayser, and D. W. Droste Clinically Silent Microemboli in Patients With Artificial Prosthetic Aortic Valves Are Predominantly Gaseous and Not Solid Stroke, February 1, 1997; 28(2): 322 - 325. [Abstract] [Full Text]
|
|
|
|
|
|
U. Sliwka, A. Lingnau, W.-D. Stohlmann, P. Schmidt, M. Mull, R. R. Diehl, and J. Noth Prevalence and Time Course of Microembolic Signals in Patients With Acute Stroke: A Prospective Study Stroke, February 1, 1997; 28(2): 358 - 363. [Abstract] [Full Text]
|
|
|
|
|
|
M. Daffertshofer, S. Ries, U. Schminke, and M. Hennerici High-Intensity Transient Signals in Patients With Cerebral Ischemia Stroke, October 1, 1996; 27(10): 1844 - 1849. [Abstract] [Full Text]
|
|
|
|
|
|
J. Molloy and H. S. Markus Multigated Doppler Ultrasound in the Detection of Emboli in a Flow Model and Embolic Signals in Patients Stroke, September 1, 1996; 27(9): 1548 - 1552. [Abstract] [Full Text]
|
|
|
|
|
|
H. Markus, J. M. Bland, G. Rose, M. Sitzer, and M. Siebler How Good Is Intercenter Agreement in the Identification of Embolic Signals in Carotid Artery Disease? Stroke, July 1, 1996; 27(7): 1249 - 1252. [Abstract] [Full Text]
|
|
|
|
|
|
H. Markus Importance of Time-Window Overlap in the Detection and Analysis of Embolic Signals Stroke, November 1, 1995; 26(11): 2044 - 2047. [Abstract] [Full Text]
|
|
|
|
|
|
H. S. Markus and M. J. Harrison Microembolic Signal Detection Using Ultrasound Stroke, September 1, 1995; 26(9): 1517 - 1519. [Full Text]
|
|
|
|
|
|
L. Valton, V. Larrue, P. Arrue, G. Geraud, and A. Bes Asymptomatic Cerebral Embolic Signals in Patients With Carotid Stenosis : Correlation With Appearance of Plaque Ulceration on Angiography Stroke, May 1, 1995; 26(5): 813 - 815. [Abstract] [Full Text]
|
|
|
|
|
|
M. Sturzenegger, J. H. Beer, and F. Rihs Monitoring Combined Antithrombotic Treatments in Patients With Prosthetic Heart Valves Using Transcranial Doppler and Coagulation Markers Stroke, January 1, 1995; 26(1): 63 - 69. [Abstract] [Full Text]
|
|