Surgical Endoscopy

, Volume 11, Issue 10, pp 1040–1044

The sensitivity of new color systems in blood-flow diagnosis

The maximum entropy method and angio-color-comparative in vitro flow measurements to determine sensitivity
  • C.  Sohn
  • H. P.  Weskott

DOI: 10.1007/s004649900522

Cite this article as:
Sohn, C. & Weskott, H. Surg Endosc (1997) 11: 1040. doi:10.1007/s004649900522


Background: Two new blood-flow-diagnosis techniques have recently been developed as supplements to the established color techniques: the MEM (maximum entropy method) technique and color flow amplitude (power Doppler). These are capable of representing blood flow in distinctly more slowly flowing areas than is possible with the conventional Doppler technique.

Methods: Both methods make use of the Doppler technique in part, yet analyze the reflected signal in a different manner, in so doing optimizing the relation between the noise and the signal. Measurements were obtained on two anatomic flow models to test the sensitivity of both techniques under slow flow conditions.

Results: The slowest flow the MEM technique was capable of recording was 0.5 mm/s, whereas the angiotechnique was able to detect 0.4 mm/s, albeit utilizing a 5-MHz transducer for the MEM technique and a 10-MHz transducer for the angio technique. One may thus assume that the MEM technique would be still more sensitive when utilizing a 10-MHz transducer. The advantage of the MEM technique is its real-time flow representation: The angio technique requires a few seconds of acquisition time. This could have serious consequences during clinical utilization. Doppler sonography was merely capable of detecting a minimum flow velocity of 15 mm/s. The angio technique is less dependent on the angle during flow representation than the MEM technique.

Conclusions: The distinctly higher sensitivity of these two new color techniques offers new possibilities in the clinical sector as far as the perfusion diagnosis of organs and tumors is concerned.

Key words: MEM technique — Color flow amplitude — Sensitivity to slow blood velocities 

Copyright information

© Springer-Verlag New York Inc. 1997

Authors and Affiliations

  • C.  Sohn
    • 1
  • H. P.  Weskott
    • 2
  1. 1.Department for Prenatal and Gynecological Ultrasound Diagnosis and Therapy, Clinic of Gynecology, University of Heidelberg, GermanyDE
  2. 2.Medical Clinic II, Siloah City Hospital, Hannover, GermanyDE

Personalised recommendations