Comparison of Tissue Stiffness Using Shear Wave Elastography in Men with Normal Testicular Tissue, Testicular Microlithiasis and Testicular Cancer

Elastography of the Male Pelvic Region-Perspectives on Malignant Lesions

Ultrasound elastography is widely used to assess tissue stiffness for lesion characterization, including differentiation between benign and malignant lesions. This study focuses on the use of elastography in the male pelvis, including the prostate, testicles, and rectum, by comparing elastography types (shear wave and strain). This article provides a summary of the existing literature on the use of elastography in the male pelvic region and outlines the clinical perspective. Ultrasound elastography is a good technique for evaluating and monitoring lesions in the male pelvic region.

Imaging Techniques to Differentiate Benign Testicular Masses from Germ Cell Tumors

PURPOSE OF REVIEW

To discuss role of different diagnostic imaging modalities in differentiation of benign testicular masses from seminomatous germ cell tumors (SGCTs) and non-seminomatous GCTs (NSGCTs).

RECENT FINDINGS

New modalities of ultrasonography, including contrast enhancement and shear wave elastography, may help differentiate between benign and malignant intratesticular lesions. Ultrasonography remains the recommended imaging modality for initial evaluation of testicular masses. However, MRI can be used to better define equivocal testicular lesions on US.

Testicular Evaluation Using Shear Wave Elastography (SWE) in Patients with Varicocele

PURPOSE

To assess the possible influence of the presence of varicocele on the quantification of testicular stiffness.

METHODS

Ultrasound with shear wave elastography (SWE) was performed on 48 consecutive patients (96 testicles) referred following urology consultation for different reasons. A total of 94 testes were studied and distributed in three groups: testes with varicocele (group A, n = 19), contralateral normal testes (group B; n = 13) and control group (group C, n = 62). Age, testicular volume and testicular parenchymal tissue stiffness values of the three groups were compared using the Kruskal-Wallis test.

RESULTS

The mean age of the patients was 42.1 ± 11.1 years. The main reason for consultation was infertility (64.6%). The mean SWE value was 4 ± 0.4 kPa (kilopascal) in group A, 4 ± 0.5 kPa in group B and 4.2 ± 0.7 kPa in group C or control. The testicular volume was 15.8 ± 3.8 mL in group A, 16 ± 4.3 mL in group B and 16.4 ± 5.9 mL in group C. No statistically significant differences were found between the three groups in terms of age, testicular volume and tissue stiffness values.

CONCLUSION

Tissue stiffness values were higher in our control group (healthy testicles) than in patients with varicocele.

Sonoelastography for Testicular Tumor Identification: A Systematic Review and Meta-Analysis of Diagnostic Test Accuracy

The objective of this review was to summarize the applications of sonoelastography in testicular tumor identification and inquire about their test performances. Two authors independently searched English journal articles and full conference papers from CINAHL, Embase, IEEE Xplore®, PubMed, Scopus, and Web of Science from inception and organized them into a PIRO (patient, index test, reference test, outcome) framework. Eleven studies (n = 11) were eligible for data synthesis, nine of which (n = 9) utilized strain elastography and two (n = 2) employed shear-wave elastography. Meta-analyses were performed on the distinction between neoplasm (tumor) and non-neoplasm (non-tumor) from four study arms and between malignancy and benignity from seven study arms. The pooled sensitivity of classifying malignancy and benignity was 86.0% (95%CI, 79.7% to 90.6%). There was substantial heterogeneity in the classification of neoplasm and non-neoplasm and in the specificity of classifying malignancy and benignity, which could not be addressed by the subgroup analysis of sonoelastography techniques. Heterogeneity might be associated with the high risk of bias and applicability concern, including a wide spectrum of testicular pathologies and verification bias in the reference tests. Key technical obstacles in the index test were manual compression in strain elastography, qualitative observation of non-standardized color codes, and locating the Regions of Interest (ROI), in addition to decisions in feature extractions. Future research may focus on multiparametric sonoelastography using deep learning models and ensemble learning. A decision model on the benefits-risks of surgical exploration (reference test) could also be developed to direct the test-and-treat strategy for testicular tumors.

The Relationship of Testicular Sonoelastography with Gonadotropin Hormone Levels and Sperm Parameters

Background: Elastography is a non-invasive medical imaging technique that helps determine the stiffness of organs and other structures in our body. In this study, we investigated the effectiveness of elastography in the diagnosis of infertility. Aim

In this study, we aimed to examine the relationship between testicular elastography and hormonal parameters and sperm parameters.

Patients and Methods

The study included 136 patients, 272 testicles were examined, and the mean age of the study participants was 30.1 years. Testicular tissue stiffness was measured by scrotal ultrasonographic shear wave elastography. Gonadotropin and testosterone hormones were measured from blood samples. Spermiogram parameters were studied manually.

Results

The control group included 66 patients, and the varicocele group consisted of 70 patients. Testicular stiffness degrees of the control group were measured as 4.29 kPa for the right testis and 4.23 kPa for the left testis. The varicocele group was divided into grades 1, 2, and 3 according to physical examination. In group 1 (grade 1), the right testis was 4.07 ± 1.24 kPa and the left testis was 3.77 ± 0.98 kPa. In group 2 (grade 2), the right testis was 4.31 ± 1.40 kPa and the left testis was 3.98 ± 0.93 kPa. In group 3 (grade 3), the right testis was 4.73 ± 1.50 kPa and the left testis was 3.99 ± 1.68 kPa. Hormone and sperm parameters were not statistically significant when comparing the control and varicocele groups. There was no statistical significance between the testicular tissue stiffness degrees of the control and varicocele groups. Hormone and spermiogram findings were also similar in groups.

Conclusion

It is known that varicocele leads to histological tissue changes in the testes. These changes result in tissue softness and loss while affecting sperm parameters and testosterone levels in a negative way. Before varicocele surgery, there is a need for new imaging methods with more sensitivity that can detect tissue changes in the testes.

Association between testicular cancer and microlithiasis

INTRODUCTION

Currently, no evidence determines the relationship between testicular microlithiasis by itself, or in relation with other factors, as a risk factor for the development of testicular tumors. There are no clear recommendations regarding the follow-up of this medical condition. Therefore, this review aims to provide a guide to monitoring these patients, supported by the literature.

METHODOLOGY

A literature review was carried out in December 2021 in PubMed, Cochrane, and Trip databases, and the selection of the articles was made following the PRISMA 2020 recommendations.

RESULTS

Overall, the four systematic reviews chosen to conduct the final study determined that the combination of microlithiasis testicular with other risk factors further increased cancer development. However, the likelihood of testicular cancer risk is similar to that of the general population.

CONCLUSIONS

Patients at risk of developing testicular cancer should undergo personalized monitoring according to their age, associated risk factors, infertility, and testicular dysgenesis syndrome to determine their follow-up needs or perform a testicular biopsy.

Ultrasound and Magnetic Resonance Imaging of Burned-Out Testicular Tumours: The Diagnostic Keys Based on 48 Cases

The spontaneous regression of testicular germ-cell tumours is a rare event whose mechanisms have yet to be elucidated. In the majority of published cases, tumour regression is concomitant with the metastatic development of the disease. Residual lesions, often referred to as burned-out testicular tumours (BOTTs), are difficult to diagnose due to the paucity of published data, especially in the field of imaging. The aim of this article is to describe the radiological signs of BOTTs on multimodal ultrasound and multiparametric MRI from a series of 48 patients whose diagnosis was confirmed histologically. The demographic, clinical and laboratory characteristics of the patients are studied, as well as the data of the imaging examinations, including conventional scrotal ultrasound, shear-wave elastography, contrast-enhanced ultrasound (CEUS) and multiparametric MRI. A total of 27 out of 48 patients were referred for investigation of primary testicular lesion following the discovery of retroperitoneal metastases, 18/48 patients were referred because of lesions suspected on an ultrasound that was performed for an infertility work-up, and 3/48 were referred because of scrotal clinical signs. Of these last 21 patients (infertility work-up/scrotal clinical sign), 6 were found to be metastatic on the extension work-up. Of the 48 orchiectomy specimens, tumour involution was complete in 41 cases, and a small active contingent remained in 7 cases, with 6 suspected upon advanced US and MRI. Typically, BOTTs appear on a conventional ultrasound as ill-delineated, hypoechoic and hypovascular nodular areas. Clustered microliths (60.4%) and macrocalcifications (35.4%) were frequent. Shear-wave elastography showed areas of focal induration (13.5 ± 8.4 vs. 2.7 ± 1.2 kPa for normal parenchyma, p < 0.01) in 92.5% of the patients for whom it was performed, and contrast ultrasonography demonstrated hypoperfusion of these lesions. Of the 42 MRIs performed, BOTTs corresponded to nodules on T2-weighted sequences (hyposignal) with significantly increased ADC values compared with healthy parenchyma (2 ± 0.3 versus 1.3 ± 0.3 × 10−3 mm2/s, p < 0.01) and an enhancement defect after injection. This enhancement defect overlapped the lesions visible on T2-weighted sequences in most cases. In the case of predominant partial regression, an enhanced portion after contrast injection was visible on MRI in all seven patients of our series, and in six of them a focal diffusion restriction zone was also present. Spontaneously involuted testicular germ-cell tumours have specific radiological signs, and all of the mentioned examinations contribute to this difficult diagnosis, even histologically, because there is no tumour cell left. These signs are similar whether the patient is initially symptomatic metastatic or whether the discovery is fortuitous on the occasion of an infertility work-up, and whatever the seminomatous or non-seminomatous nature of the germ-cell tumour, when this can be determined. The appearance of regressed germ-cell tumours is often trivialized, which can lead to the wrong diagnosis of an extra gonadal germ-cell tumour (in metastatic patients) or of scarring from an acute event such as trauma or infection, which is not recognized or forgotten. In our series, two patients had an unrecognized diagnosis in their history, with local and/or distant recurrence. An improvement in diagnosing burned-out tumours, combining advanced US and MRI, is necessary in order to optimize patient management, with special attention paid to asymptomatic patients, to prompt extension screening and orchiectomy with analysis of the whole testis. This may reveal a persistent viable tumour or lesions of germinal neoplasia in situ, which are precursors of testicular germ-cell tumours.

Shear wave elastography for the evaluation of testicular salvage after testicular torsion

The aim of this study was to assess the utility of shear wave elastography in the follow-up of testicular detorsion, evaluate long-term outcomes, and explore its relationship with parameters such as tissue stiffness values, pain duration, and torsion type. Elastography examinations were independently performed by two radiologists to evaluate patients who presented to our hospital for follow-up after being diagnosed with testicular torsion and age-matched controls. Inter-observer variability of the mean testicular tissue elasticity was excellent (Intraclass correlation coefficient: 0.939, p < 0.001). Median time between testicular detorsion and follow-up ultrasound examination was 18 months (range, 11-36 months). Torsion side, torsion degree, and pain duration were recorded, and testicular volumes were calculated. The study population comprised 24 patients (48 testes) with a mean age of 21.1 ± 7.8 years. The mean testicular volume was measured as 12.3 ± 5.4 ml for the testicular salvage group, 13.9 ± 3.8 ml for the contralateral testes, and 13.7 ± 2.7 ml for the control group (p = 0.553). The mean testicular speed mode values were higher in the testicular salvage group (1.34 ± 1.21 m/s) compared with the contralateral testes group (1.00 ± 0.08 m/s), and the control group (1.01 ± 0.06 m/s), however there was no statistically significant difference between the three groups (p = 0.861). While testicular atrophy was detected in three patients, an intraparenchymal wedge-shaped focal hypoechoic area developed after torsion in a further three patients. The elastography examination for focal hypoechoic areas revealed an increase or decrease in tissue stiffness compared to the normal parenchyma. The tissue stiffness values of the testicular salvage group were higher in complete torsion compared to incomplete torsion. The elastography method contributes to other imaging methods in distinguishing focal lesion areas that can be seen after testicular torsion from malignant conditions. Elastography presents as a feasible and practical complementary modality for the follow-up of testicular salvage after torsion.

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.

Contemporary options and future perspectives: three examples highlighting the challenges in testicular cancer imaging

PURPOSE

One of the main issues in testicular germ cell tumors (TGCTs) management is to reduce the necessary amount of treatment to achieve cure. Excess treatment burden may arise from late diagnosis of the primary as well as from false positive or negative staging results. Correct imaging is of paramount importance for successful management of TGCT. The aim of this review is to point out the current state of the art as well as innovative developments in TGCT imaging on the basis of three common challenging clinical situations.

METHODS

A selective literature search was performed in PubMed, Medline as well as in recent conference proceedings.

RESULTS

Regarding small testicular lesions, recent studies using elastography, contrast-enhanced ultrasound or magnetic resonance imaging (MRI) showed promising data for differentiation between benign and malignant histology. For borderline enlarged lymph nodes FDG-PET-CT performance is unsatisfactory, promising new techniques as lymphotropic nanoparticle-enhanced MRI is the subject of research in this field. Regarding the assessment of postchemotherapeutic residual masses, the use of conventional computerized tomography (CT) together with serum tumor markers is still the standard of care. To avoid overtreatment in this setting, new imaging modalities like diffusion-weighted MRI and radiomics are currently under investigation. For follow-up of clinical stage I TGCTs, the use of MRI is non-inferior to CT while omitting radiation exposure.

CONCLUSION

Further efforts should be made to refine imaging for TGCT patients, which is of high relevance for the guidance of treatment decisions as well as the associated treatment burdens and oncological outcomes.

Ultrasonography of the scrotum: Revisiting a classic technique

Conventional US is the primary imaging modality for the evaluation of the scrotum, due to its high resolution, availability, cost-effectiveness and absence of ionizing radiation. Grayscale and color Doppler US provide a comprehensive assessment of scrotal diseases. The technique represents the mainstay for imaging of acute scrotum. US is highly accurate in the detection, localization and characterization of scrotal masses. Multiparametric US, including conventional US, contrast-enhanced US and tissue elastography has improved the diagnostic performance of the technique in the assessment of testicular diseases. MRI represents a valuable supplemental imaging tool for the investigation of scrotal pathology, mainly recommended in cases of indeterminate US findings. Recommendations recently issued by the European Society of Urogenital Radiology Scrotal and Penile Imaging Working Group (ESUR-SPIWG) refer to the use of scrotal sonography for the evaluation of pathologic entities, including testicular microlithiasis, small, non-palpable incidentally detected testicular masses, varicocele and scrotal trauma. In this review, the technical specifications for scrotal US and the normal sonographic findings are presented. Grayscale and color Doppler US findings of common acute scrotal diseases and scrotal masses are discussed. The complimentary role of multiparametric US and scrotal MRI is addressed. ESUR-SPIWG's guidelines are also reviewed.

Causal contributors to tissue stiffness and clinical relevance in urology

Mechanomedicine is an emerging field focused on characterizing mechanical changes in cells and tissues coupled with a specific disease. Understanding the mechanical cues that drive disease progression, and whether tissue stiffening can precede disease development, is crucial in order to define new mechanical biomarkers to improve and develop diagnostic and prognostic tools. Classically known stromal regulators, such as fibroblasts, and more recently acknowledged factors such as the microbiome and extracellular vesicles, play a crucial role in modifications to the stroma and extracellular matrix (ECM). These modifications ultimately lead to an alteration of the mechanical properties (stiffness) of the tissue, contributing to disease onset and progression. We describe here classic and emerging mediators of ECM remodeling, and discuss state-of-the-art studies characterizing mechanical fingerprints of urological diseases, showing a general trend between increased tissue stiffness and severity of disease. Finally, we point to the clinical potential of tissue stiffness as a diagnostic and prognostic factor in the urological field, as well as a possible target for new innovative drugs.

Role of multiparametric ultrasound in testicular focal lesions and diffuse pathology evaluation, with particular regard to elastography: Review of literature

BACKGROUND

Ultrasound is the main requested technique for the assessment of traumatic, vascular, neoplastic, and inflammatory testicular pathology. Moreover, the role of ultrasound has broadened over the years along with the introduction of new techniques, such as contrast enhanced ultrasound and ultrasound elastography.

OBJECTIVE

An updated representation of the pre-existing Literature evidence for multiparametric ultrasound imaging with particular regard to elastography, in the evaluation of focal and diffuse testicular pathologies, has been presented.

METHODS

The search was performed in PubMed, Cochrane, EMBASE, Web of Science and Scopus databases from the earliest available article (1977) until January 2021. Based on the evidence of the Literature, the current role of US imaging for focal and diffuse testicular pathologies has been reported and illustrated, with emphasis on examination technique, classification, and pitfalls.

RESULTS

Multiparametric Ultrasound has a recognized role for testicle focal and diffuse disease. Elastography is nowadays recognized as an essential part of the multiparametric ultrasound examination. However, in the setting of testicular pathology this method showed some promising results in the setting of varicocoele and for focal lesions characterization. In the remaining field its role is still under debate.

DISCUSSION

B-mode ultrasound and color Doppler ultrasound have been for a long time the diagnostic gold standard for testicular pathologies. The introduction of both contrast enhanced ultrasound and elastography in the last two decades has brought to the emergence of the multiparametric ultrasound concept. These methods are currently able to increase diagnostic confidence especially for testicular lesions characterization, with different relevance depending on the pathology under consideration.

CONCLUSION

Multiparametric ultrasound testis assessment, with specific regard to elastography is nowadays recommended for focal and diffuse disease evaluation. Further and larger studies are however needed to validate these results and to understand if the role of elastography in testicular pathology may be broadened.

Historical trends for the standards in scrotal ultrasonography: What was, what is and what will be normal

BACKGROUND

Ultrasonography is the gold standard imaging method for scrotal investigation. Colour Doppler ultrasonography, contrast-enhanced ultrasonography and sonoelastography allow sonographers to assess size, echotexture, vascular features and stiffness of the scrotal organs and abnormalities. Scrotal ultrasonography has been used to investigate male reproductive health, scrotal pain, masses and trauma. However, ultrasonography thresholds/classifications used to distinguish normal and pathologic features of the scrotal organs have changed over time, and have not yet been fully standardized.

OBJECTIVES

To evaluate historical trends for the standards in scrotal ultrasonography: what was, what is and what will be normal.

METHODS

An extensive Medline search was performed identifying the most relevant studies in the English language from inception to date.

RESULTS

We provide here (i) a brief overview of the history of ultrasonography, (ii) current indications for scrotal ultrasonography and (iii) previous and current normal values, cut-offs and classifications of the main colour-Doppler ultrasonography parameters/characteristics of the scrotal organs, as derived from recent guidelines and evidence-based studies. In addition, we report recommendations and the clinical utility of contrast-enhanced ultrasonography and sonoelastography. Finally, we discuss critical issues needing further evidence and future directions to fill in the current gaps.

DISCUSSION

Several studies on scrotal ultrasonography are available. However, guidelines/recommendations dealing with specific ultrasonography applications have been published only in recent years. More recently, the European Academy of Andrology published evidence-based scrotal colour-Doppler ultrasonography reference ranges/normative parameters derived from a cohort of healthy, fertile men. In addition, a standardization of the methodology to evaluate qualitative and quantitative colour-Doppler ultrasonography parameters was reported. Other international societies reported indications, methodological standards, clinical utility and limitations of contrast-enhanced ultrasonography and sonoelastography.

CONCLUSIONS

To date, colour-Doppler ultrasonography normative values for the scrotal organs are available. However, a wide international consensus on assessment and classification of several ultrasonography parameters is still lacking. An alignment of the world societies on these issues is advocated.

3D Printing Improved Testicular Prostheses: Using Lattice Infill Structure to Modify Mechanical Properties

Patients often opt for implantation of testicular prostheses following orchidectomy for cancer or torsion. Recipients of testicular prostheses report issues regarding firmness, shape, size, and position, aspects of which relate to current limitations of silicone materials used and manufacturing methods for soft prostheses. We aim to create a 3D printable testicular prosthesis which mimics the natural shape and stiffness of a human testicle using a lattice infill structure. Porous testicular prostheses were engineered with relative densities from 0.1 to 0.9 using a repeating cubic unit cell lattice inside an anatomically accurate testicle 3D model. These models were printed using a multi-jetting process with an elastomeric material and compared with current market prostheses using shore hardness tests. Additionally, standard sized porous specimens were printed for compression testing to verify and match the stiffness to human testicle elastic modulus (E-modulus) values from literature. The resulting 3D printed testicular prosthesis of relative density between 0.3 and 0.4 successfully achieved a reduction of its bulk compressive E-modulus from 360 KPa to a human testicle at 28 Kpa. Additionally, this is the first study to quantitatively show that current commercial testicular prostheses are too firm compared to native tissue. 3D printing allows us to create metamaterials that match the properties of human tissue to create customisable patient specific prostheses. This method expands the use cases for existing biomaterials by tuning their properties and could be applied to other implants mimicking native tissues.

Multiparametric ultrasonographic analysis of testicular tumors: a single-center experience in a collective of 49 patients

Purpose: The aim of the present retrospective single-center study is to evaluate the diagnostic performance of multiparametric ultrasonography for characterizing testicular tumors.Method: Forty-nine patients with testicular tumors, 36 of malignant vs 13 of benign entity, were included in this retrospective single-center study on whom multiparametric sonography, encompassing native B-mode, Color Doppler, contrast-enhanced ultrasound (CEUS) and elastography, was performed between 2011-2018. In 48 of 49 patients, findings from multiparametric analysis were correlated with histopathological results. The applied contrast agent for CEUS was a second-generation blood pool agent. Ultrasonography examinations were performed and interpreted by a single experienced radiologist with more than 15 years of experience (EFSUMB Level 3).Results: Multiparametric ultrasonography was successfully performed in all included patients without any adverse effects. Concomitant testicular microlithiasis, rapid arterial wash-in, elevated values for perfusion quantification - Peak Enhancement (PE), Wash-in Area Under the Curve (WiAUC) and Wash-in Perfusion Index (WiPI) - and higher shear wave velocities were significantly associated with malignancy.Conclusions: Multiparametric ultrasonography depicts a non-ionizing, directly accessible and cost-effective imaging modality that allows for the extensive characterization of testicular tumors, thereby helping to discriminate between malignant and benign entity of testicular tumors.

Using shear wave elastography method to evaluate testicular compartment syndrome after testicular torsion

The measurement of compartment pressure is a direct method to objectively evaluate suspected compartment syndrome. However, to evaluate the evolving compartment syndrome, one needs to measure the pressure repeatedly, which may aggravate the damage of tissue. Despite several suggested approaches, an effective, noninvasive and sustainable method to detect testicular compartment syndrome is still lacking. In this context, using the method of shear wave elastography, we assessed the correlation between the intratesticular pressure and the testicular compartment elasticity (Emean) after testicular torsion in rabbits. It was found that a strong correlation between the intratesticular pressure and the Emean in the testicular border area (p < .001) or the central area (p = .001) was present. This result suggests that shear wave elastography is a reliable method to evaluate intratesticular pressure in rabbits, and it may have further potential clinical application in detecting testicular compartment syndrome.

Shear-wave elastography of the testicle: potential role of the stiffness value in various common testicular diseases

AIM

To assess the value and efficacy of real-time shear-wave elastography (SWE) of normal testicular parenchyma and various common testicular diseases in clinical practice.

MATERIALS AND METHODS

SWE was undertaken in 338 patients (mean age: 43.2±17.2 years, range 17-78 years) comprising normal testicles (n = 358), testicular microlithiasis (n = 40), and various testicular diseases (n = 208) and the stiffness was recorded. The final diagnosis was correlated with the clinical context, long-term follow-up, or histopathology. Statistical evaluation was performed to provide a stiffness threshold for pathological diagnosis.

RESULTS

The mean size of testicular lesions was 2.6±1.5 cm (range: 10-42 mm). The mean Young's modulus value for normal testis was recorded at 4.55±2.54 kPa. Whatever the stage of microlithiasis, a higher statistically significant stiffness value was recorded. For acute orchitis, the mean stiffness value was slightly higher, but not statistically significantly. The testicular tumoural processes presented a median stiffness value of 21.02 kPa with a cut-off of 16.1 kPa. Fibrosis presented the highest median stiffness value of 30.03 kPa with a cut-off of 26.3 kPa. By analysing the distribution of the different pathological groups, the difference was statistically significant between fibrosis and tumoural processes (p = 0.001).

CONCLUSION

SWE is a feasible technique in the exploration of the testicular parenchyma. SWE values can be used to differentiate testicular fibrosis from a tumoural process with confidence.

[Testicular tumors: A diagnostic challenge of imaging]

OBJECTIVES

Reviewing the characterization and the follow-up imaging of testicular tumors.

MATERIAL AND METHODS

Literature review (PubMed, Medline) of urological and radiological studies dealing with testicular tumors using keywords: Testicular tumors; Color Doppler ultrasound; US elastography; Magnetic resonance imaging; Contrast enhanced sonography.

RESULTS

Ultrasound remains the basic exam for the tumor characterization. Among the other techniques, MRI, elastography, contrast enhanced ultrasound, although still in evaluation, will be increasingly used in the future. The frequency of benign Leydig cell tumors justifies a testicular preservation approach, through improvement of characterization, monitoring or tumorectomy. The follow-up of testicular lesions must be indicated on precise indications: follow-up of the contralateral testicle in the case of germi cell tumor, follow-up by of a supposed benign lesion, such as a small Leydig cell tumor in an infertile patient, follow-up when ultra-sound findings are not sufficiently worrying to require immediate diagnosis but which include pejorative criteria. The tumor markers and the extension screening remain systematic.

CONCLUSION

The era of total orchiectomy for any uncertain testicular lesion is over. We try the challenge of characterization, and define management's algorithms based on clinical biological data and suspected nature of the tumor at imaging.

Characterization of Testicular Masses in Adults: Performance of Combined Quantitative Shear Wave Elastography and Conventional Ultrasound

We prospectively evaluated the performance of combined shear wave elastography (SWE) and conventional ultrasound (US) for the characterization of 89 testicular focal masses. Testes were evaluated with B-mode, color Doppler and SWE measurements, locating a region of interest on the normal and pathologic parenchyma. Thirty-seven malignant tumors (MTs), 12 burned out tumors (BOTs), 28 Leydig cell tumors (LCTs), 2 dermoid cysts and other benign lesions were included. MTs + BOTs exhibited more microliths and macrocalcifications compared with benign lesions (p < 10^-4). LCTs manifested mostly a dominant peripheral vascularization pattern compared with other lesions. MTs + BOTs were stiffer compared with benign lesions (p < 2 × 10^-4) but with a moderate area under the receiver operating characteristic curve (AUROC) of 80%. By focusing on LCTs versus MTs + BOTs, diagnostic performance led to an AUROC of 89% for the best stiffness parameter. For combined conventional US and SWE, the diagnostic performance to differentiate all benign lesions versus MTs + BOTs and LCTs versus MTs + BOTs increased to AUROCs of 93% and 98%, respectively.

Elastography of focal testicular lesions: current concepts and utility

As a relatively new sonographic technique, tissue elastography has emerged as a qualitative and potentially quantitative adjunctive tool to provide additional information on tissue stiffness, aiming to further improve diagnostic confidence in discriminating benign from malignant focal testicular lesions. The purpose of this review is to provide an overview of the elastography techniques used to assess focal testicular lesions and their typical appearance on tissue elastography.