The Value of Sonoelastography Scores and the Strain Ratio in Differential Diagnosis of Azoospermia

Abstract

We evaluated the diagnostic performance of real-time elastography for differentiating nonobstructive from obstructive azoospermia. We evaluated 1,192 testes, including 584 with nonobstructive azoospermia, 408 with obstructive azoospermia and 200 controls, from men with a mean ± SD age of 30 ± 5 years. Two radiologists evaluated the testes using a 5-degree elastography score system. The strain ratio was calculated on line. Of 156 azoospermic testes 78 were diagnosed by bilateral testicular biopsy for diagnostic purposes or sperm harvesting. In our software system a score of 3 indicated average strain, and scores 4 and 5 indicated low strain. Average or low strain (score 3 to 5) was seen in 477 of 584 testes with nonobstructive azoospermia (81.7%). This rate was significantly higher than the rate in obstructive azoospermic and control testes (68 of 408 or 16.3% and 30 of 200 or 15.0%, p <0.001). The strain ratio significantly differed for nonobstructive and obstructive azoospermia (median 0.490 and 0.340, Z = -20.560, p <0.001). Real-time elastography is a promising imaging method with great potential for the differential diagnosis of azoospermia.