Measurement of the speed of sound in follicular fluid.

Journal article

BACKGROUND: Measurement of ovarian follicles by ultrasound is common practice in fertility treatment. However, the effect of the speed of sound is not taken into account. We present results from a study aimed at measuring this. METHODS: The speed of sound was measured in samples of follicular fluid aspirated from patients undergoing fertility treatment. The transmitted and received pulses from a single element ultrasound transducer were recorded using a digital oscilloscope for a pulse passed through a sample of the fluid. The distance over which the pulse travelled was known from calibration with pure water. Variation with temperature was investigated in the range 25-45 degrees C. Dependence on ultrasound frequency, patient and time from aspiration were also investigated. RESULTS: The speed of sound in follicular fluid was found to be 1550+/-3 m/s at 37.3 degrees C using 5.0 MHz ultrasound. The speed varied from 1528+/-3 m/s at 24.8 degrees C to 1561+/-3 m/s at 44.8 degrees C. Variation with patient, time and frequency were not detected. CONCLUSION: The speed of sound in follicular fluid at body temperature is 1550 m/s. This small difference from the speed assumed by the ultrasound machine corresponds to the systematic bias in volume measurement evident in previously published results.

Authors: Gooding, M; Barber, D; Kennedy, S; Noble, J

• Publication status: Published
• Journal: Human reproduction (Oxford, England) More from this journal
• Volume: 20
• Issue: 2
• Pages: 497-500
• Publication date: 2005-02-01
• DOI: 10.1093/humrep/deh591
• EISSN: 1460-2350
• ISSN: 0268-1161
• Language: English
• Keywords: Ultrasonography; Infertility, Female; Female; Calibration; Follicular Fluid; Fertilization in Vitro; Humans; Temperature; Reference Values; Biopsy, Needle