Evaluation of the potential role of shear wave elastography as a promising predictor of sperm retrieval in non-obstructive azoospermic patients: A prospective study

Prediction of testicular histology in azoospermia patients through deep learning-enabled two-dimensional grayscale ultrasound

ABSTRACT

Testicular histology based on testicular biopsy is an important factor for determining appropriate testicular sperm extraction surgery and predicting sperm retrieval outcomes in patients with azoospermia. Therefore, we developed a deep learning (DL) model to establish the associations between testicular grayscale ultrasound images and testicular histology. We retrospectively included two-dimensional testicular grayscale ultrasound from patients with azoospermia (353 men with 4357 images between July 2017 and December 2021 in The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China) to develop a DL model. We obtained testicular histology during conventional testicular sperm extraction. Our DL model was trained based on ultrasound images or fusion data (ultrasound images fused with the corresponding testicular volume) to distinguish spermatozoa presence in pathology (SPP) and spermatozoa absence in pathology (SAP) and to classify maturation arrest (MA) and Sertoli cell-only syndrome (SCOS) in patients with SAP. Areas under the receiver operating characteristic curve (AUCs), accuracy, sensitivity, and specificity were used to analyze model performance. DL based on images achieved an AUC of 0.922 (95% confidence interval [CI]: 0.908-0.935), a sensitivity of 80.9%, a specificity of 84.6%, and an accuracy of 83.5% in predicting SPP (including normal spermatogenesis and hypospermatogenesis) and SAP (including MA and SCOS). In the identification of SCOS and MA, DL on fusion data yielded better diagnostic performance with an AUC of 0.979 (95% CI: 0.969-0.989), a sensitivity of 89.7%, a specificity of 97.1%, and an accuracy of 92.1%. Our study provides a noninvasive method to predict testicular histology for patients with azoospermia, which would avoid unnecessary testicular biopsy.

The feasibility study of shear wave elastography in the diagnosis of erectile dysfunction

The aim of this study was to explore the value of Shear wave elastography (SWE) in evaluating vascular and nonvascular erectile dysfunction. In this study, erectile dysfunction (ED) patients enrolled (n = 114) received SWE and Doppler ultrasonography (PCDU) exams. The peak systolic velocity (PSV) and end-diastolic velocity (EDV) were used as the classification standard. The performance of the SWE was assessed with the receiver operating characteristic curve, sensitivity and specificity. The rigidity alterations of corpus cavernosum penis with age was also investigated. SWE values of corpus cavernosum penis (CCP) before intracavernosal injection (ICI) negatively correlated with age of patients in vascular ED group (r = -0.288, P < 0.05). In erectile or flaccid state, the SWE value of vascular ED was significantly larger than non-vascular ED. When the cut-off value for SWE values of CCP 0.88 m/s in erectile state and 2.32 m/s in flaccid state, the areas under the receiver operating characteristic (ROC) curve were 0.700 (sensitivity: 77.78%, specificity: 60.00%) and 0.612(sensitivity: 68.52%, specificity: 51.67%) in erectile or flaccid state, respectively. This study provides preliminary evidence that SWE in flaccid state could be non-invasive methods used to moderate predict vascular ED.

Comparison of Testicular Sonography and Elastography Findings With Semen Parameters in Cases Investigated for Infertility

OBJECTIVES

This study aimed to investigate the correlation between testicular shear wave elastography (SWE) values and semen analysis results in men with infertility.

METHODS

This was a retrospective case-control study. Patients were categorized as normal, abnormal, or azoospermic based on sperm analysis results. Testicular volume was measured using B-mode ultrasonography using the Lambert formula. Subsequently, 40-80 regions of interest measuring 1.5 × 1.5 mm were manually positioned in both testicles based on their size, and two-dimensional SWE was applied through virtual touch imaging quantification software.

RESULTS

The patients had a mean age of 33.79 ± 6.3 years, with semen analysis revealing normal results in 15 patients (22.4%), pathological findings in 35 patients (52.2%), and azoospermia in 17 patients (25.4%). Right, left, total, and mean testicular volumes were significantly lower in patients with azoospermia compared to those in both normal and impaired semen parameters (P < .05). Conversely, testicular elastography scores were higher in patients with azoospermia than in the other groups (P < .05). The significant negative correlation between volume and elastographic findings remained independent of age (r = 0.4, P < .001). The accuracy rates for detecting impaired semen parameters and azoospermia were 94.3% and 94.1%, respectively, after considering factors such as age, testicular volume (right/left/total), and elastography (right/left/total). Notably, the total mean elastography score ranked first, with 100% in the independent normalized importance distribution of these variables.

CONCLUSION

SWE can be used effectively alone or in combination with other diagnostic tools to evaluate histopathological changes in the testicles of male patients with infertility.

Elastography in the Urological Practice: Urinary and Male Genital Tract, Prostate Excluded—Review

The aim of this article is to review the utility of elastography in the day-to-day clinical practice of the urologist. An electronic database search was performed on PubMed and Cochrane Library with a date range between January 2000 and December 2021. The search yielded 94 articles that passed the inclusion and exclusion criteria. The articles were reviewed and discussed by organ, pathology and according to the physical principle underlying the elastographic method. Elastography was used in the study of normal organs, tumoral masses, chronic upper and lower urinary tract obstructive diseases, dysfunctions of the lower urinary tract and the male reproductive system, and as a pre- and post-treatment monitoring tool. Elastography has numerous applications in urology, but due to a lack of standardization in the methodology and equipment, further studies are required.

Application of real-time shear wave elastography in the assessment of male infertility

BACKGROUND

Shear wave elastography (SWE) is recognized as a suitable imaging modality for identifying and characterizing testicular diseases. Recent exploration of SWE has focused on its feasibility in evaluating histopathological changes in the testicular parenchyma, with researchers increasingly focusing on the relationship between testicular stiffness and male fertility. In this study, we aimed to investigate the diagnostic value of SWE for distinguishing the relationship between spermatogenic defects and testicular stiffness in males of reproductive age.

METHODS

This was a single center, cross-sectional study conducted from July 2017 to December 2019. A total of 1,116 consecutive patients who were voluntarily participating in in-vitro fertilization (IVF)-assisted conception at our hospital were recruited to the study. The cohort included 497 normozoospermia patients (Group I), 335 with normozoospermia and decreased motility and agglutination (Group II), 138 with oligozoospermia (Group III), 105 with non-obstructive azoospermia (Group-NOA), and 41 with obstructive azoospermia (Group-OA). We conducted SWE of each participant's testes and the testicular elastic modulus was calculated. The differences of testicular elastic modulus were compared among groups. Linear regression analysis was conducted to determine the correlation between sperm concentration and either testicular volume or testicular elastic modulus. Receiver operating characteristic (ROC) curves were drawn to evaluate the diagnostic efficiency of the maximum elastic modulus (Emax), mean elastic modulus (Emean), and maximum minus the minimum elastic modulus {E[max-min]}.

RESULTS

The Emax, Emean, and E[max-min] increased gradually in groups I, II, III, and Group-NOA, with statistical differences between groups (P<0.01). Testicular volume was shown to be positively correlated with sperm concentration (r=0.476; P<0.01), while the Emax, Emean, and E[max-min] were negatively correlated with sperm concentration (r=-0.511, -0.357, and -0.524, respectively; P<0.01). The ROC curves were established based on the Emax, Emean, and E[max-min] and were used to distinguish Group-OA from Group-NOA. The areas under the ROC curve (AUCs) were 0.910, 0.863, and 0.900, respectively. We also used ROC curves to distinguish the severe oligozoospermia subgroup and Group-NOA from other groups, for which the AUCs were 0.877, 0.791, and 0.878, respectively.

CONCLUSIONS

The SWE is an effective supplement to routine ultrasound examination and can be used to diagnose and differentiate spermatogenetic dysfunction.