Comparative study of standard and small transrectal transducers for prostate ultrasonography.

Purpose: The objective of this study was to evaluate pain and image quality associated with the use of two different ultrasound transducers.

Methods: Fifty healthy male participants aged 30 years or older were prospectively enrolled. All ultrasound procedures were performed using a V8 machine (Samsung Medison, Seoul, Korea) equipped with EA2-11 (conventional) and miniER7 (small-caliber) transrectal transducers, operated by a single genitourinary radiologist. To minimize bias, one group of volunteers underwent ultrasonography with the conventional transducer first, followed by the small transducer. For the remaining participants, the examinations were performed in the opposite order. Ultrasonography, including the measurement of total prostate and transitional zone volumes, was conducted in accordance with standard practice. After testing with both probes, participants were asked to rate their pain on a 10-point numerical rating scale (NRS). A radiologist then evaluated the quality of the images acquired with each probe using a 5-point numeric scale and compared the prostate volume measurements obtained by each method.

Results: The mean NRS scores associated with the conventional and small transducers were 4.7±1.8 and 2.7±1.2, respectively (P<0.05). The mean ultrasound image qualities from the two transducers were statistically similar (4.78 and 4.74, P>0.05). The whole prostate gland volume as measured with the conventional transducer (mean±standard deviation, 24.2±9.1 mL) was greater than the measurement (22.1±8.7 mL) obtained with the small-caliber transducer (P<0.05). However, only two of the 50 whole gland volume measurements differed by more than two standard deviations.

Conclusion: The use of a small transrectal probe significantly reduced pain without compromising image quality.