The Use of a Stand-of Device in High Pulse Repetition Frequeny Doppler Echocardiography

Abstract

An interesting case of severe mitral stenosis in which Doppler echocardiographic evaluation was greatly enhanced by use of a stand-off pad is discussed. When employing high pulse repetition frequency (HPRF) Doppler, it may be difficult to place the sample volume at the area of interest while remaining in HPRF mode, because it is not always clear that there is a certain minimum sample volume depth below which a system will not operate in HPRF. This and other related technical constraints vary from machine to machine. This case illustrates that sample volumes can be manipulated by using a stand-off pad, thereby making use of HPRF possible. The specifications of the HPRF mode on the Acuson 128XP (Acuson, Mountain View, CA) are examined in detail, and possible applications of this technique in similar difficult situations that may arise in clinical practice are discussed.

Keywords

high pulse repetition frequency high PRF stand-off pad pressure half-time mitral stenosis Doppler echocardiography

References

1. Pearson J . Thyroid, parathyroids, and neck, in Kawamura DM , Berman MC , Craig M (eds). Diagnostic Medical Sonography, Volume 3: Abdomen. Philadelphia: JB Lippincott, 1992;521-540.

2. Carr-Hoefer C . Breast, in Kawamura DM , Berman MC , Craig M (eds). Diagnostic Medical Sonography, Volume 3: Abdomen. Philadelphia: JB Lippincott, 1992;541-578.

3. Walter JP . Physics of high-resolution ultrasound: practical aspects. Radiol Clin North Am 1985;23:3-12.

4. Topper LW , Sanders RC . Neck mass, in Sanders RC , Miner NS (eds). Clinical Sonography: A Practical Guide. Second Edition. Boston: Little Brown and Co., 1991;369-376.

5. Delemarre BJM , Bot H , Pearlman AS , et al. Diastolic flow characteristics of severely impaired left ventricles: a pulsed Doppler study. J Clin Ultrasound 1987;15:115-119.

6. Hatle L : Doppler measurements of high velocity with pulsed Doppler, in Hatle L (ed). Doppler Ultrasound in Cardiology, Second Edition. Philadelphia: Lea & Febiger, 1982;293-305.

7. Nishimura RA , Abel MD , Hatle LK , et al. Assessment of diastolic function of the heart: background and current applications of Doppler echocardiography, Part II. Clinical studies. Mayo Clin Proc 1989;64:181-204.

8. Appleton CP , Hatle I . The natural history of left ventricular filling abnormalities: assessment by two-dimensional and Doppler echocardiography. Echocardiography 1992;9:437-457.

9. Voelker W , Regele B , Dittman H , et al. Effect of heart rate on transmitral flow velocity and Doppler measurements of mitral valve area in patients with mitral stenosis. Eur Heart J 1992;13:152-159.

10.

10. Drinkovic N , Smith MD , Wisenbaugh T , et al. Influence of sampling site upon the ratio of atrial to early diastolic transmitral flow velocities by Doppler. J Am Coll Cardiol 1987;9(suppl): 16A-16A. Abstract.

11.

11. Ding Z , Oh J , Klein A , Tajik J . Effect of sample volume location on Doppler-derived transmitral inflow velocity values. J Am Soc Echo 1991;4:451-456.