Potential role of imaging in assessing harmful effects on spermatogenesis in adult testes with varicocele

Dynamic contrast-enhanced MRI in the assessment of testicular perfusion in infertile men with clinical varicocele

BACKGROUND

Varicocele represents the most common correctable cause of male infertility. The presence of non-invasive imaging parameters providing evidence as to which patients with varicocele are at risk for infertility would be important.

PURPOSE

To explore the role of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) using semi-quantitative parameters in the assessment of testicular perfusion in infertile men with clinical varicocele.

MATERIAL AND METHODS

The study cohort included 11 infertile men with clinical varicocele and six controls, with prior paternity. Subtraction DCE-MRI was performed after gadolinium administration, using a three-dimensional fast field-echo sequence. Time-signal intensity curves were created and semi-quantitative parameters were calculated. The independent samples t-test was used to compare basic T1 perfusion parameters between infertile testes with clinical varicocele and normal testes. Logistic regression analysis was performed to assess the most significant predictor of the diagnosis of clinical varicocele.

RESULTS

Both testes with clinical varicocele and normal testes enhanced moderately and homogeneously, with a linear increase of enhancement throughout the examination. Higher mean values of maximum enhancement (P = 0.026), maximum relative enhancement (P = 0.024), and wash-in rate (P = 0.013) were detected in the testes of infertile men with clinical varicocele, compared to the normal population. The wash-in rate proved the most significant predictor of the diagnosis of clinical varicocele (P = 0.013).

CONCLUSION

DCE-MRI may provide a valuable insight into the testicular perfusion of infertile men with clinical varicocele. The wash-in rate proved a strong and independent predictor of the diagnosis of clinical varicocele.

Shear Wave Elastography for Assessment of Testicular Stiffness in Patients with Varicocele: A Prospective Comparative Study

Background

The purpose of this study was to use ultrasonography and shear wave elastography (SWE) to assess stiffness and volume of testes in adult patients with varicocele, to compare the results with those of normal contralateral testes of the same patients and healthy testes of control subjects.

Methods

In this IRB-approved prospective comparative study, 58 patients with varicocele (116 testes) and 58 control patients (116 testes) were enrolled. A total of 66 testes with varicocele were added to group A, their 50 healthful contralateral testes were added to Group B, and 116 healthy control testes were added to Group C. Analysis of variance (one way ANOVA) test was used to compare groups and Student's t-test was used for their binary comparisons. The correlation between the testicular stiffness and volume was studied using Pearson's correlation test.

Results

There was not a significant difference in the mean SWE values between three groups and also, between two-group comparisons (P < 0.05). In the mean testicular volumes, a significant difference was observed between Groups A and C (P = 0.028). Conversely, there was not a significant difference between Groups A and B (P = 0.907) or Groups B and C (P = 0.094). A meaningful correlation between testicular stiffness and volume was not detected for each group.

Conclusion

A significant correlation was not determined between SWE values and varicocele, and also between SWE values and testicular volume. We advise that more studies with larger populations of patients are required to verify the effectiveness of SWE in predicting testicular parenchymal damage.

Minocycline can reduce testicular apoptosis related to varicocele in male rats

The current research aimed to assess the impacts of Minocycline on varicocele-induced regulation of apoptotic-related genes and oxidative stress in the testis of adult Wistar rats. Thirty-two rats were divided into 4 groups: sham, varicocele (VcI), varicocele treated with Minocycline (VcI + Mno) for 56 days and healthy rats treated with minocycline (Mno). After 8 weeks, the oxidative stress markers levels in serum were investigated, afterwards, the level of Bax and Bcl-2 expression were assessed through 'immunocytochemistry' and RT-qPCR assays. Also, the rate of apoptosis was evaluated through the TUNEL method. Johnson's score, 'the width of epithelium' and 'seminiferous tubules diameter' were ameliorated in the VcI + Mno group in comparison with the Vcl group. Administration of Minocycline raised the 'Glutathione peroxidase' and 'Superoxide dismutase' levels in serum and declined the Malondialdehyde level in serum (p = 0.001). Furthermore, current study represented that minocycline reduced Bax and enhanced the expression of Bcl-2 gene and protein in comparison with the Vcl group (p < 0.05). In addition, Minocycline administration significantly declined the rate of apoptosis in germ cells (p < 0.05). Our study demonstrated that the administration of Minocycline could improve testicular injury in varicocele-induced rats by its antioxidant activity.

The usefulness of elastography in the evaluation and management of adult men with varicocele: A systematic review

Objective

To review the role of elastography in the evaluation and decision-making of adult, infertile men with varicocele.

Methods

A systematic search using the terms (Elastography) AND (Varicocele), (Stiffness) AND (Varicocele), (Elastography) AND (Male infertility) was performed in Pubmed/Medline. Studies reporting a) elastographic characteristics in varicocele-bearing comparing to normal testicles, and b) the correlation of elastography with varicocele grading, parameters of spermatogenesis, and outcomes of varicocele treatment were selected. Exclusion criteria were animal, adolescents, abstracts, and non-English language studies.

Results

In total, 453 articles were identified; 11 eligible studies were selected. Several modalities were used (shear wave elastography, strain elastography, quasistatic ultrasound elastography, acoustic radiation force impulse). Varicocele-bearing testicles have significantly different stiffness and elasticity in comparison to normal and non-varicocele testicles. Although not in full agreement, elastography readings are correlated with semen parameters. Conflicting results were reported regarding grading as most of the studies failed to demonstrate a significant correlation. Shear wave elastography showed a significant correlation with the improvement in semen parameters after varicocelectomy, but the association with pregnancy rates is unknown. Finally, no studies were identified comparing elastography with other modalities.

Conclusions

Elastography can detect changes in the architecture of varicocele-bearing testicles. Although the role of the modality in grading is uncertain, elastography showed a meaningful correlation with spermatogenesis parameters. Importantly, elastography readings could predict the improvement in semen parameters after varicocelectomy which is useful in terms of decision-making in infertile men with varicocele.

Abbreviations

ARFI: acoustic radiation force impulse; CDUS: colour Doppler ultrasonography; DWI: diffusion-weighted imaging; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; SWE: shear wave elastography; VC: varicocele.

A preliminary study of shear-wave elastography for the evaluation of varicocele in adolescents and young adults

PURPOSE

The purpose of this study was to use shear-wave elastography (SWE) to assess testicular stiffness changes during the Valsalva maneuver in adolescents and young adults with varicocele, to compare these changes according to clinical severity, and to evaluate the role of SWE in the diagnosis of varicocele.

METHODS

This study included patients undergoing testicular ultrasonography for the diagnosis of varicocele or for post-varicocelectomy follow-up between June 2016 and February 2017. Fifty-four testicles of 27 consecutive patients (mean age, 15.9 years) were classified by clinical grade (grade 0-3). Using SWE, mean testicular stiffness (Emean) was measured at rest and during the Valsalva maneuver. The correlations between multiple ultrasonographic parameters (volume asymmetry, Emean at rest, and absolute and percentage changes in Emean during the Valsalva maneuver) and clinical grade were assessed using the Spearman correlation test.

RESULTS

The Emean at rest was similar across clinical grades. During the Valsalva maneuver, increased testicular stiffness was frequently observed in patients with grade 2 or 3 varicocele but rarely observed in those with grade 0 or 1 varicocele. The changes in Emean were positively correlated with the clinical grade (all P<0.001), whereas the Emean at rest and volume asymmetry were not (all P>0.05).

CONCLUSION

A transient, reversible increase in testicular stiffness during the Valsalva maneuver was observed in adolescents with high-grade varicocele, and the degree of stiffness change was correlated with the clinical grade. Stiffness change identified using SWE during the Valsalva maneuver is a potential surrogate indicator of venous congestion.

When to ask for an MRI of the scrotum

Background

Multiparametric MRI (mpMRI) of the scrotum has been established as a useful second‐line diagnostic tool for the investigation of scrotal diseases. Recently, recommendations on clinical indications for scrotal MRI were issued by the Scrotal and Penile Imaging Working Group of the European Society of Urogenital Radiology.

Objective

To update current research on when to ask for an MRI of the scrotum.

Methods

PubMed database was searched for original articles and reviews published during 2010–2021.

Results

Eighty‐three articles fulfilled the search criteria. Scrotal MRI is mainly recommended after inconclusive US findings or inconsistent with the clinical examination and should be asked in the following cases: differentiation between intratesticular and paratesticular lesions (in rare cases of uncertain US findings), characterization of paratesticular and intratesticular lesions (when US findings are indeterminate), discrimination between germ cell and sex cord‐stromal testicular tumors, local staging of testicular malignancies (in patients planned for testis‐sparing surgery), differentiation between seminomas and non‐seminomatous tumors (when immediate chemotherapy is planned and orchiectomy is delayed), assessment of acute scrotum and scrotal trauma (rarely needed, in cases of non‐diagnostic US findings) and detection and localization of undescended testes (in cases of inconlusive US findings). Although preliminary data show promising results in the evaluation of male infertility, no established role for mpMRI still exists.

Conclusion

Multiparametric MRI of the scrotum, by assessing morphologic and functional data represents a valuable problem‐solving tool, helping to improve our understanding on the nature of scrotal pathology and the process of spermatogenesis. The technique may improve patient care and reduce the number of unnecessary surgical procedures.

Proton MR Spectroscopy in Assessing the Biochemical Milieu of Human Testes

Proton magnetic resonance spectroscopy (MRS), considered a connection between metabolism and anatomic and functional information provided by standard MRI, gives information on various tissue metabolites and their pathologic changes. Recently, proton MRS has been added as an adjunct tool to the multiparametric protocol of scrotal MRI, providing a new insight into the extremely complex biochemical milieu of normal and abnormal testes. This article reviews proton MR spectra of normal testes, showing age and bilateralism dependence. Disturbances of various metabolic pathways in testes of infertile men resulting in alterations of metabolite peaks are discussed. Preliminary data on proton MR spectra of testicular mass lesions are presented. LEVEL OF EVIDENCE: 5. TECHNICAL EFFICACY STAGE: 5.

Ultrasensitive Doppler as a tool for the diagnosis of testicular ischemia during the Valsalva maneuver: a new way to explore varicoceles?

Background

Varicocele is among the most common causes of male infertility because of various mechanism, including hypoxia.

Purpose

To evaluate testicular vascularization (TV) with ultrasensitive Doppler before and during the Valsalva maneuver (VM) and correlate TV changes to varicocele’s spermatic venous reflux graduated by color Doppler.

Material and Methods

From January to February 2016, 69 men (135 testis) referred for scrotal ultrasound were prospectively enrolled. An institutional review board approved the study. As gold standard, the spermatic venous reflux in the supratesticular region was assessed with color Doppler ultrasound and graded from 0 to III. A new ultra-sensitive Doppler (USD) sequence was performed on testicular parenchyma in an axial view. The TV changes before and during the VM were qualitatively graded from 0 to 2 using a visual scale by consensus. The vessels surface was quantified using customized MATLAB® software, and compared to the testicular delineated surface, resulting in a vessels surface ratio (VSR). The absolute and relative VSR difference before and during the VM was calculated. The qualitative scale and the quantitative VSR changes were compared with the spermatic venous reflux grade using an analysis of variance.

Results

A strong correlation has been found between the spermatic venous reflux grade and TV decrease during the VM using USD, for qualitative graduation as well as for quantitative measurement ( P < 0.0001).

Conclusion

TV assessed by USD decreased significantly during the VM in patients with varicocele; this decrease was significantly associated with spermatic venous reflux grade.

Normal Changes and Ranges of Pediatric Testicular Volume and Shear Wave Elasticity

To determine normal ranges for pediatric testicular volume and stiffness values (SV) on ultrasonography (US) and shear wave elastography (SWE) with respect to age and weight, testicular US scans (including SWE) of children (<10 y old) performed from February 2015 to January 2017 were retrospectively reviewed; grossly normal testes or testes with small hydroceles were included. Correlations between age weight, and testicular volume or SV were evaluated. Among a total of 52 boys (1-92 mo, median = 23.5 mo), there were positive correlations between testicular volume and age (R² = 0.451, p < 0.001) and weight (R² = 0.515, p < 0.001). Testicular SV was negatively correlated with age (R² = 0.166, p = 0.051) and weight (R² = 0.372, p = 0.049). Therefore, SV decreases while volume increases with increasing weight in testes of healthy children. Normal ranges for testicular volume and SV in children younger than 10 y are reported.

Correlation between Testicular Hemodynamic and Semen Quality Indices in Clinical Varicocele Patients in Pakistan

Varicocele, a vascular event, is associated with infertility due to testicular damage that causes abnormal spermatogenesis in males. The goal of this study is to ascertain the diagnostic significance of scrotal color Doppler ultrasonography (CDUS) by measuring peak systolic value (PSV) and resistive index (RI) of the arteries supplying blood to the testis and their association with semen quality attributes. Sixty prospective patients (age: 20-50 years) undergoing microsurgical varicocelectomy at a teaching hospital were included in the study. Semen parameters and CDUS were recorded and testicular blood flow was determined as PSV and RI of subcapsular artery and intraparenchymal artery of the testes. Nonparametric statistics was applied to test the correlation/association of the semen quality with the PSV, RI, and other variables. Results revealed a significant negative correlation (r = -0.28; p < 0.05) between progressive motility of spermatozoa and resistive index of the intraparenchymal arterial blood flow. Furthermore, it was noticed that the progressive motility of spermatozoa was tended to be negatively correlated (r = -0.236) with resistive index of subcapsular arterial blood flow. In conclusion, this study has revealed that progressive motility of sperms has correlation with the intraparenchymal blood flow of testes. The progressive motility of sperms could be correlated with RI of testicular blood flow. The apparent lack of association between diameter of varicocele vein and semen quality signifies the need of investigating some other factors that may be involved in pathogenicity of varicocele. The diagnostic value of CDUS may be carefully interpreted and clinically correlated in assessment of severity of varicocele.

Protective effect of ghrelin on testicular damages caused by chronic hypoxia in rats: A histopathological study

Hypoxia can lead to changes in the blood flow, nutrition and oxygenation of male germ cells and results in fertility reduction through the increase in oxidative stress. This study aims to evaluate the effect of ghrelin on testicular damage induced by hypoxia in rats. In this experimental study, 24 male rats were randomly divided into four groups: control, hypoxia, hypoxia + ghrelin and ghrelin. Animals in the control and ghrelin groups were kept in room air with 21% oxygen. The animals in the groups of hypoxia and hypoxia + ghrelin were subjected to 11% oxygen for 14 consecutive days in the hypoxia chamber. At the end of the study, the testes were removed and histological changes, as well as the apoptotic index, were investigated. Morphometrical analysis showed that hypoxia caused a significant decrease in the seminiferous tubules diameter, the germinal epithelium thickness and main Johnson's score compared to the control group (p < .05). In addition, statistical comparisons revealed a significant increase in the apoptotic index in the hypoxia group (p < .05). Administration of ghrelin + hypoxia improved the parameters mentioned above (p < .05). The results of this study indicated that ghrelin decreases the testicular damages caused by hypoxia in the rats by antioxidative activity.