Assessment of Testicular Resistivity Index by Color Doppler Ultrasonography as a Predictor of Male Spermatogenesis, with Semen Analysis as the Gold Standard
Dr Ahmad Mumtaz, Dr Furqan Ahmad, Dr Mehboob Ahmad, Dr Ujyara Meryem
Chugtai Labs Lahore
Vol: 16/02
Received: January 25, 2026 Accepted: May 02, 2026 Published: June 28, 2026
Abstract
Background: Color Doppler Ultrasonography (CDUS) with the testicular resistive index (RI) represents a non-invasive approach to testicular perfusion and its relationship with spermatogenesis.
Objective: To determine the diagnostic quality of testicular resistivity index assessed by Color Doppler Ultrasonography as a predictor of spermatogenesis based on semen analysis as the gold standard.
Methodology: This diagnostic validation cross-sectional study was carried out at the Department of Radiology, Chughtai Lab, Lahore, within a period of three months. The non-probability consecutive sampling method was used to include 257 males between 18 and 50 years with suspected infertility. Color Doppler Ultrasonography was used to measure testicular RI, where RI ≥ 0.6 is abnormal. Sperm count of <million/mL or <39 million per ejaculate defined infertility, and semen analysis was carried out. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were estimated. Analysis of ROC curves was conducted.
Results: Out of the 257 participants, 98 (38.1%) were found to be infertile in semen analysis. A RI ≥0.6 was detected in 95 (37.0) patients. Sensitivity, specificity, PPV, NPV, and diagnostic accuracy of RI were 86.7%, 93.7%, 89.5%, 92.0%, and 91.8%, respectively. ROC analysis indicated an AUC of 0.91 with an optimum RI cut-off of 0.6.
Conclusion: Testicular resistive index is a dependable non-invasive indicator of spermatogenesis, with a high diagnostic accuracy, and can be used as a useful complement to semen analysis in the diagnosis of male infertility.
Keywords: Male infertility, Testicular resistive index, Color Doppler Ultrasonography, Spermatogenesis.