RESUMO
PURPOSE: The aim of this study was to compare testicular volumes measured by Prader orchidometer and scrotal ultrasound. MATERIALS AND METHODS: The volumes of 467 adult male testes were measured by Prader orchidometer and scrotal ultrasound. The testicular volumes on ultrasound were calculated by the formula: length x width x height x 0.71. The testicular volumes of the Prader orchidometer were divided into two groups: 15 ml or less, and over 15 ml. The two measurements were compared for each group. RESULTS: In the group with testicular volumes of 15 ml or less, the testicular volumes measured by orchidometer(13.29+/-1.94 ml) were significantly smaller than those measured by ultrasound(14.83+/-2.76 ml). In contrast, the group with over 15 ml did not show any significant difference in the volumes measured by orchidometer(21.21+/-2.58 ml) versusultrasound(20.77+/-4.26 ml). Mean paired differences of the testicular volumes between the orchidometer and ultrasound were 1.54+/-2.65 ml for the group with 15 ml or less and -0.44+/-3.38 ml for the group over15 ml these values are significantly different. CONCLUSIONS: In cases of testicular volume of 15 ml or less measured by Prader orchidometer, scrotal ultrasound is necessary for an accurate measurement of the volume.