Utility of Real-Time Shear Wave Elastography in the Assessment of Testicular Torsion

Non-invasive evaluation of testicular torsion using ultrasound shear wave elastography: an experimental study

PURPOSE

The goal of this study was to examine changes in testicular stiffness at various intervals after the induction of testicular torsion, as well as to assess the predictive value of testicular stiffness for testicular spermatogenesis after torsion.

METHODS

Sixty healthy male rabbits were randomly assigned to one of three groups: complete testicular torsion, incomplete testicular torsion, or control. All rabbits underwent preoperative and postoperative scrotal ultrasonography, including shear wave elastography (SWE), at predetermined intervals. Changes in SWE values were analyzed and compared using repeatedmeasures analysis of variance. To assess the diagnostic performance of SWE in determining the degree of spermatogenic function impairment, the areas under the receiver operating characteristic curves (AUCs) were calculated.

RESULTS

SWE measurements in both central and peripheral zones of the testicular parenchyma affected by torsion demonstrated significant negative correlations with spermatogenesis, with coefficients of r=-0.759 (P<0.001) and r=-0.696 (P<0.001), respectively. The AUCs of SWE measurements in the central or peripheral zones of the torsed testicular parenchyma were 0.886 (sensitivity, 83.3%; specificity, 100%) and 0.824 (sensitivity, 83.3%; specificity, 73.3%) for distinguishing between hypospermatogenesis and spermatogenic arrest, respectively (P=0.451, DeLong test).

CONCLUSION

Variations in the stiffness of both central and peripheral regions of the testicular parenchyma correlate with the extent and duration of torsion, exhibiting a specific pattern. The "stiff ring sign" is the characteristic SWE finding associated with testicular torsion. SWE appears to aid in the non-invasive determination of the extent of spermatogenic damage in torsed testes.

The value of multimodal ultrasonography in the evaluation of late presenting testicular torsion in a rat experimental model

OBJECTIVE

To evaluate the value of multimodal ultrasonography (US) in a rat experimental torsion model after 6 h of torsion with different degrees.

METHODS

Twenty-one male rats were divided into three groups. Left testes of the rats were twisted around their vascular pedicle 360 degrees in group 1, 720 degrees in group 2, and 1080 degrees in group 3 and intact right testes of the rats were accepted as control group. Grey-scale US, superb microvascular imaging (SMI), colour Doppler ultrasonography (CDUS), strain elastography (SE), and two-dimensional (2-D) shear wave elastography (SWE) examinations were applied 6 h after torsion procedure and testes were removed for pathological evaluation.

RESULTS

Short-axis dimensions and volumes of the torsion side were higher than control testes. Lengths of the testes in the 3rd torsion group were smaller than the testes in groups 1 and 2 (P < 0.002). SMI was better than CDUS in recognizing blood flow in testicular tissue. Strain ratios were higher in group 1 and decreased with the increasing torsion degree. Emean and standard deviation (SD) measurements increased in the torsion side. Pathologically the mean testicular damage scores were statistically significant between torsion and control testes in all groups.

CONCLUSION

Our results showed that short-axis and volume measurements, SMI, 2D-SWE, and SE are effective in the evaluation and diagnosis of testicular torsion (TT).

ADVANCES IN KNOWLEDGE

Evaluation of affected testis and intact testis with multiparametric US in late presenting TT cases is more reliable than being dependent on a single sonographic modality.

Diagnostic role of gray-scale and shear-wave elastography in pediatric patients with undescended testes: a prospective controlled study

Aim

Ultrasound elastography is a simple non-invasive method for measuring tissue elasticity in relation to tissue fibrosis. The aim of this study was to compare echogenicity, volume and shear wave velocities of undescended vs normally descended testes.

Material and methods

Sixty-six boys with undescended testes were included in this study. The median age range was 35.5 (10-118) months old. The cases included in this prospective study consisted of 66 patients with non-operated undescended testes, with 51 of them being affected unilaterally and 15 affected bilaterally, as diagnosed by physical examination. The control group consisted of 31 healthy boys without any particular health problems. This prospective study was performed by gray-scale ultrasonography and shear wave elastography in boys with undescended testes and healthy testes. The testicular volumes were established by ultrasound measurement, the echogenicity and shear wave elastography values were measured in boys with unilateral and bilateral undescended testes, and the results were compared with healthy boys' testes and their contralateral testes. The stiffness values were recorded for speed (m/s) and elasticity (kPa), and the stiffness values of undescended testes were compared with the healthy control group.

Results

Echogenicity values were lower in the bilateral undescended testes group than in the healthy group, and the healthy group's echogenicity was normal (p <0.001). The ROC curve was used to identify a cut-off shear wave elastography value for predicting decreased testicular echogenicity by using average shear wave elastography values. The area under the curve for the undescended testes was 0.78 (95% CI: 0.70-0.85, sensitivity 83.7%, specificity 68.7%, p <0.001), with an average shear wave elastography value of 2.32 (m/s) for above the cut-off point indicates. This was found to be significantly associated with reduced echogenicity on gray-scale ultrasonography, suggesting that it may be correlated with fibrosis developing in patients with undescended testes.

Conclusion

The study provides interesting findings in that it proposes an alternative non-invasive method for the assessment of testicular tissue in undescended testes. We used shear wave elastography to compare the stiffness of normal testes in both heathy patients and in the contralateral healthy testes of boys with undescended testes, with the values obtained for the undescended testes reflecting the level of fibrosis of the parenchyma. Another outcome of this study was observed in patients with unilateral undescended testes, where the normally descended testes showed increased shear wave elastography values, which could be an early indication of parenchymal change.

Effects of acetylsalicylic acid and ultrasound elastography on testicular torsion in rats

Background/aim

To investigate the effects of acetylsalicylic acid (ASA) and the use of ultrasound elastography on testicular torsion.

Materials and methods

Herein, 6 equal groups of rats were formed (n: 48): control group, sham group, torsion/detorsion (T/D)-1 h group, T/D-1 h + ASA group, T/D-8 h group, and T/D-8 h + ASA group. Testicular torsion was created by rotating the left testis 720° clockwise. At 30 min before torsion, 100 mg/kg of ASA was injected intraperitoneally. Elastography was performed at 8 and 24 h. After orchiectomy, specimens were collected for histopathological evaluation.

Results

When comparing the left testicular volume (LV) parameters obtained from the elastography applied at 8 h, significant differences were observed between the following group pairs: the sham and T/D-8 h groups, T/D-1 h and T/D-8 h groups, and T/D-1 h + ASA and T/D-8 h groups (p = 0.004, p = 0.023, and p = 0.026, respectively). The mean LVS (velocity) (stiffness assessment) of the groups was similar at 8 h. When comparing the LV parameters at 24 h, significant differences were found between the T/D-1 h and T/D-8 h groups and between the T/D-8 h and T/D-8 h + ASA groups (p = 0.008 and p = 0.004, respectively). For the LVS mean values at 24 h, significant differences were found between the control and sham groups, sham and T/D-1 h groups, sham and T/D-8 h groups, and sham and T/D-8 h + ASA groups (p = 0.009, p = 0.021, p = 0.027, and p = 0.009, respectively).Histopathological evaluation showed a decrease in the morphological grades and an increase in the mean testicular injury scores in the T/D-1 h + ASA group compared to the T/D-1 h group. The T/D-8 h + ASA group had a higher morphological grade than the T/D-8 h group, whereas their mean testicular injury scores were similar.

Conclusion

ASA treatment for testicular torsion was shown to be ineffective. Elastography can be a complementary method to Doppler ultrasonography in the diagnosis of testicular torsion and can guide surgeons in their approach to surgery.

Exploring the anatomical factors influencing testes elasticity via ultrasound shear wave elastography: Preliminary results

PURPOSE

The aim of this study is to evaluate the anatomical factors influencing elasticity values of normal testicular parenchyma using shear wave elastography (SWE).

METHODS

This study examined 68 healthy male volunteers (117 testes in which standard transverse axis ultrasonography views could be obtained) via conventional scrotal ultrasonography and SWE. Both the mean (EMean) and standard deviation (ESD) elasticity values were acquired.

RESULTS

In the standard transverse axis view of the rete testis at the mid-lateral edge of the testes, the EMean values in 2mm the testicular parenchyma from the rete testis and the testicular capsule at the same level as the rete testis were all significantly larger than in the central zone (P<0.001, P<0.001, respectively). The EMean value in the testicular parenchyma 2mm from the testicular capsule on the line formed approximately 45° below the horizontal line of the rete testis was significantly larger than in the rete testis approximately 45° above the horizontal line (P<0.001). In two standard transverse axis views, the ESD values in other regions were significantly larger than those in the central zones (all P<0.001). Also, the EMean values in the transmediastinal arteries were larger than those of the surrounding normal testicular parenchyma (P<0.001).

CONCLUSION

Based on SWE, factors including the testicular capsule, the density of testicular fibrous septa, the depth of the Q-Box™, and the transmediastinal artery may influence the testes elasticity measurement.

Radiological Evidence of Testicular Damage in Severe Acute Respiratory Syndrome Coronavirus 2 Infection: A Sonoelastography's Potential Role

ABSTRACT

This preliminary study aimed to evaluate the possible damage to the male reproductive system that the severe acute respiratory syndrome coronavirus 2 virus causes by quantitatively measuring and comparing the tissue stiffness of the testis and epididymis with acoustic radiation force impulse sonoelastography in patients who have COVID-19 with a healthy control group. This prospective study was conducted between February and July 2021 with 65 cases. We used sonoelastography to evaluate male patients 18 years or older, who had applied to the urology clinic with nontesticular complaints, and were found to not have any underlying testicular pathology after a clinical-laboratory evaluation. The clinical-laboratory imaging findings and reverse transcription-polymerase chain reaction test results of all patients diagnosed with COVID-19 were reviewed from the hospital database. We measured the shear wave velocity values of the epididymis and the testes of 31 proven severe acute respiratory syndrome coronavirus 2 patients and 34 healthy subjects and compared them with an independent t test. For the patient and control group subjects, the mean age was 37.55 ± 13.08 (23-71) and 40.5 ± 16.25 (18-81) years, respectively. The mean shear wave velocity values of the left-right and bilateral testes and epididymis of the patient group were statistically substantially higher ( P ˂ 0.05) than in the control group. In the receiver operating characteristic analysis, when the cutoff values for the bilateral testes and epididymis were determined as 1.39 and 1.64 m/s, respectively, the AUC was 77% to 73.4%, the sensitivity was 87% to 74%, and the specificity was 65% to 62%. Our findings show that testicular and epididymal tissue stiffness increased in patients with COVID-19. We recommend adding sonoelastography to urogenital examinations of male reproductive system in patients who are recovering from COVID-19.

Variability, Validity and Operator Reliability of Three Ultrasound Systems for Measuring Tissue Stiffness: A Phantom Study

Introduction

Ultrasound elastography is a method of measuring soft tissue stiffness to detect the presence of pathology. There are several ultrasound elastography devices on the market. The aim of this study was twofold. Firstly, to determine the validity of three different ultrasound systems used to measure tissue stiffness. Secondly, to determine the operator reliability and repeatability when using these three systems.

Materials and methods

Two observers undertook multiple stiffness measurements from a phantom model using three different ultrasound systems; the LOGIQ E9, the Aixplorer, and the Acuson S2000. The phantom model had four cylindrical-shaped inclusions (Type 1-4) of increasing stiffness values and diameter embedded within. The background phantom stiffness was fixed. The mean, standard deviation, and coefficient of variation (CV) were calculated from measured stiffness readings per diameter per inclusion. Intra-observer variability was assessed. The validity of the measured stiffness value was assessed by calculating the difference between the measured elasticities and actual phantom elasticities. Bland-Altman plots with limits of agreement were used to display the inter-observer agreement. The intraclass correlation coefficients (ICC) were used to measure intra-observer, inter-observer, and inter-system reliability.

Results

Each observer undertook 1020 measurements. All three systems generally underestimated the stiffness values for the inclusions; the higher the actual stiffness value, the more significant the underestimation. The percentage difference between measured stiffness and actual stiffness varied from -79.1% to 12.7%. The intra-observer variability was generally less than 5% for observers using the LOGIQ E9 and the Aixplorer systems but more than 10% over the stiffer inclusions (Types 3 and 4) for the Acuson system. There was 'almost perfect' intra-observer reliability and repeatability for both the LOGIQ E9 and the Aixplorer systems; this was 'moderate' for the Acuson system over specific inclusions. For all systems, there was 'almost perfect' inter-observer reliability and repeatability between Observer A and Observer B. The inter-system reliability and repeatability were 'almost perfect' between the LOGIQ E9 system and the Aixplorer system but 'poor' and 'moderate' when the Acuson system was matched with the LOGIQ E9 system and the Aixplorer system, respectively.

Conclusion

This study has demonstrated that the Acuson, LOGIQ E9, and Aixplorer ultrasound systems have low variability, high reproducibility, and good intra-observer and inter-observer reliability when used to measure tissue stiffness. However, they all underestimated the stiffness values during this in vitro study. This study also revealed that not all ultrasound systems are comparable when measuring tissue stiffness, with some having better inter-system reliability than others. Ongoing standardization of technology is required at the manufacturer level.

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.

Ultrasound elastography in children - nice to have for scientific studies or arrived in clinical routine?

Ultrasound elastography (USE) is a modality that in addition to fundamental B-mode, Doppler, and contrast-enhanced sonography is suitable to make qualitative and quantitative statements about the stiffness of tissues. Introduced more than 20 years ago in adults, USE becomes now a diagnostic tool also in children. The aim of this paper is to describe current available techniques for USE in children. The significance for routine use in children is shown, and further interesting applications are reported.

Ultrasound shear-wave elastography applicability in estimation of post-mortem time

Introduction

Post-mortem rigidity of the tissues is one of the basic principles in forensic medicine to estimate the time of death. Qualitative methods to determine the stiffness of the corpse may have some limitations. Methods that provide quantitative values may be useful. We intended to evaluate the applicability of ultrasound shear-wave elastography of the tissues to estimate the post-mortem interval (PMI).

Methods

For 80 corpses, shear-wave elastography of the liver, sartorius muscle, testis, thyroid and parotid was performed before autopsy. Based on the forensic reports as the reference method to define post-mortem interval, the corpses were divided into four groups: group 0 (PMI < 24 hours), group 1 (PMI ≥24 hours and <48 hours), group 2 (PMI ≥ 48 hours and <72 hours), and group 3 (PMI ≥ 72 hours). There were 24, 38, 13, and 5 corpses, respectively, in groups 0, 1, 2, and 3.

Results

A significant rise in the elasticity values in comparison to elasticity of normal tissues in live adults was seen very early in the post-mortem period. Between-group comparisons showed that a significant difference in the liver elasticity was present among the groups. The mean (SD) liver elasticity was 10.29 (±0.83) in group 0, 14.98 (±1.56) in group 1, 12.49 (±1.09) in group 2, and 15.64 (±1.68) kilopascals (kPa) in group 3 (P = 0.035). Nevertheless, elasticity measurements in other tissues were not helpful in distinguishing post-mortem interval groups.

Conclusion

It is possible to use liver quantitative shear-wave elastography to estimate the time of death.

Neonatal testicular torsion

Rotation of the testis around the axis of the spermatic cord results in tissue ischaemia and testicular torsion (TT). TT in the newborn infant in the 1st month of life is referred to as neonatal TT (NTT) or perinatal TT and occurs in 6.1/100, 000 live births. The true incidence could be higher as some of these occur prenatally and can be asymptomatic. TT can be extravaginal, intravaginal and mesorchial and NTT is usually extravaginal. Physical examination can be adequate for the diagnosis, and utility of ultrasound (US) is mainly to exclude other conditions. If the timing of the torsion is prenatal, the testicle may not be salvageable. But, in certain situations, these could be asymptomatic bilateral TT. When the timing of torsion is not simultaneous (asynchronous torsion) early contralateral orchiopexy done at the time of exploration would prevent the occurence of asynchronous torsion. Non.operative maneuvres to detorse in NTT are not successful and not recommended. This review focuses on the diagnostic approach and management.

Shear-wave elastography for the assessment of testicular involvement of hematologic malignancies in children and young adults: a feasibility study

Purpose

This study aimed to assess the feasibility of shear-wave elastography (SWE) for assessing the testicular involvement of hematologic malignancies in children and young adults.

Methods

Eight patients (mean age, 11.0 years; range, 0.8 to 20 years) with biopsy-confirmed testicular involvement of hematologic malignancy between January 2018 and December 2020 were retrospectively evaluated. Multiparametric ultrasound examinations, including grayscale, color Doppler ultrasonography (CDUS), and SWE, were performed. Stiffness was measured in the involved testicular area and contralateral normal parenchyma. If there was bilateral testicular involvement, the stiffness of the involved area and the adjacent normal echoic parenchyma was measured on one testis. The Mann-Whitney U test was used to compare stiffness values.

Results

On grayscale, the testicular lesions were noted as a solitary mass in one patient, multiple lesions in four patients, and diffuse involvement in three patients. On CDUS and SWE, all patients demonstrated increased vascularity, and the stiffness of the involved area was higher than the values of normal parenchyma (the involved area vs. normal parenchyma, 11.6 kPa [3.9-20.2 kPa] vs. 2.9 kPa [1.1-3.7 kPa], P=0.003). The ratio of stiffness between the involved area and normal parenchyma was 3.4, ranging from 1.9 to 5.1. One patient showed decreased stiffness on follow-up SWE after treatment (affected testis vs. normal testis: initial, 13.8 vs. 3.2 kPa; 1 year later, 2.2 vs. 2.4 kPa).

Conclusion

Increased testicular stiffness on SWE in children and young adults with hematologic malignancies suggests the possibility of testicular involvement.

Testicular shear wave elastography in oligo-astheno-teratozoospermic individuals: a prospective case-control study

Purpose

The primary objective of this study was to evaluate the testicular stiffness by ultrasound shear wave elastography (SWE) both in men with oligo-astheno-teratozospermia (OAT) and in control group. The secondary objective was to identify a possible correlation between semen quality with testicular stiffness.

Methods

This was a prospective case-control study. We divided the sample in two groups; Group A (case group) included men with OAT, and Group B (control group) men with normal sperm parameters. All participants had at last two semen analysis in the past 180 days (at last 90 days apart), using performed ultrasound and SWE elastography.

Results

We analyzed 100 participants, 50 patients in Group A and 50 controls in Group B. There were statistically significant differences in term of testicular volume and testicular stiffness between two groups. Men with OAT had the testicular stiffness value higher than the controls in both sides (left testicular stiffness 21.4 ± 5.4 kPa vs 9.9 ± 1.6 kPa, p < 0.0001; right testicular stiffness 22.9 ± 4.8 kPa vs 9.5 ± 2.4 kPa, p < 0.0001). Men with abnormal semen parameters showed an inverse correlation between the mean value of testicular stiffness and total sperm count (22.15 ± 3.38 kPa, r = − 0.387, p = 0.005), sperm concentration (22.15 ± 3.38 kPa, r = − 0.244, p = 0.04), and progressive motility (22.15 ± 3.38 kPa, r = − 0.336, p = 0.01), while the correlation was not evident in controls group.

Conclusion

SWE is able to differentiate between testicles with spermatogenic changes from a healthy testicle. For this reason, it could be used to evaluate, in a non-invasive way, the tissue alterations of the organ.

Ultrasound evaluation of long-term outcome in boys operated on due to testicular torsion

We aimed at verifying the usefulness of spectral Doppler ultrasonography in determining development of the testis after torsion in boys.The study involved 28 patients and 30 control cases divided into 3 developmental groups: pre-pubertal, early pubertal, and pubertal. It presented surgical management in testicular torsion (TT), volume, and echogenicity of testes, as well as peak-systolic velocity (PSV), end-diastolic velocity (EDV), and vascular resistance index (RI) in the capsular and intra-testicular arteries, regarding developmental groups, detorsed testes, uninvolved ones, and testes in the control group.Orchiectomy was performed in 13 boys with complete TT, in 11 lasting for over 24 hours, and in 2 lasting for 9 and 10 hours, respectively. Orchiectomy mainly involved patients aged up to 6 years, who at the time of the follow-up ultrasound belonged to the pre-pubertal group.There is no clear correlation between the type of testicular torsion, its duration, and the echogenicity of the testis. Testicular torsion has a negative effect on the volume of detorsed testis with compensatory hypertrophy of the uninvolved testis. The study represents a new approach to the issue of long-term gonadal blood supply abnormalities after treatment of testicular torsion in childhood.

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.

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.

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

BACKGROUND AND OBJECTIVES

Testicular sperm extraction (TESE) has been a useful diagnostic and therapeutic tool with sperm retrieval opportunity varying according to the pathological finding in azoospermic patients. Sonoelastography (SE) is an exciting radiologic method that can measure relative elasticity of different tissues in a selected region of interest (ROI) by depending on fast cross-correlation technique and a combined autocorrelation method. Real-time elastography (RTE) can be used for structural analysis of testicular tissue to detect pathological tissue alterations. We aimed in the current study to evaluate the efficacy of shear wave elastography (SWE) in predicting sperm retrieval in non-obstructive azoospermic (NOA) patients undergoing TESE.

PATIENTS AND METHODS

This prospective study included 50 NOA patients who did two successive semen analyses with normal or elevated gonadotrophic hormones. All participants were subjected to SWE imaging on the testes by a radiologist. The measurements were recorded in terms of kPa using the SWE mode. They were done on each testis in the longest longitudinal plane. SWE images were viewed using dual mode: elasticity mode (kPa) and propagation (arrival time contour) mode then patients underwent TESE.

RESULTS

A significant difference in SWE values was observed between patients with successful sperm retrieval and those with negative sperm retrieval providing 94.7% negative predictive value and 50.0% positive predictive value for sperm retrieval in NOA patients undergoing TESE with 75.0% sensitivity and 85.71% specificity (p  =  0.0001). Mean stiffness index measured by SWE correlated significantly with the histopathological types as 8 patients only were diagnosed as having severe hypospermatogenesis.

DISCUSSION AND CONCLUSION

These prime data suggest that SWE as a non-invasive, easily applicable, and repeatable imaging method has a promising potential to be one of the reliable sonographic modalities that can be used as one of the predictors for sperm retrieval in NOA patients.

THE ROLE OF ULTRASOUND ELASTOGRAPHY IN THE DIAGNOSIS OF PATHOLOGIC CONDITIONS OF TESTICLES AND SCROTUM

Several years ago, elastography emerged as a potentially very useful ultrasound technique that is currently used in diagnostic workup of the breast, liver and some other organ systems, whereas for other ones it is still mainly in the phase of research. The aim of the study was to compare elasticity index (EI) of testicles using strain elastography in healthy subjects and those with pathologic changes of testicles/scrotum. A total of 117 patients were included in the study. Measurements were performed on a Logiq E9 ultrasound system using strain elastography. In healthy subjects, the mean EI value was 1.34±0.35 for right testis and 1.49±0.47 for left testis. Increased mean EI values were found in the following six conditions: patients with varicocele, infertile patients, solitary testis after orchidectomy of the other testicle because of tumor, patients with testicular tumors, patients after orchidopexy of undescended testicle, and patients with congenitally smaller testicle. There is a paucity of literature data on the use of elastography in testes, as well as on normal elastography values in testicular tissue. Strain elastography was demonstrated to be a valuable method to acquire additional information in patients with pathologic changes in testicles/scrotum. These data provide reference values for further research in a larger sample of subjects.

Perinatal testicular torsion

Testicular torsion (TT) occurs when the testis rotates around the axis of the spermatic cord attachments and prevents blood flow to the testis, resulting in tissue ischemia. If this occurs in the first month of life it is referred to as "perinatal TT" (PTT) or "neonatal TT" (NTT). PTT has an incidence of 6.1 per 100,000 live births. Some of these cases occur prenatally. It can be missed on the initial newborn examination, as it can be asymptomatic. Hence, the true incidence is much higher since it is underdiagnosed. The types of TT include extravaginal, intravaginal, and mesorchial. Most cases of PTT are extravaginal. The diagnosis can generally be made on physical examination. Ultrasonography (US) can help exclude other rare diagnoses as long as surgical intervention is not delayed. There has been some debate regarding the timing of surgery. Although the torsed testicle may not be salvageable, the likelihood of asymptomatic bilateral TT has to be borne in mind and contralateral orchiopexy done at the time of exploration would prevent an asynchronous torsion. Nonoperative maneuvers to detorse in PTT are not recommended. The evaluation, diagnostic approach, and management of this relatively rare condition are described.

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.

Management of testicular torsion <360° in children: a single-center, retrospective study

Objective

This study aimed to summarize clinical manifestations, and physical examination, laboratory examination, and ultrasound results of children with testicular torsion <360°.

Methods

We performed a retrospective study of children who were diagnosed with testicular torsion <360° between October 2007 and October 2017.

Results

There were 11 (19.2%) patients with testicular torsion of 90°, 33 (58.0%) with 180°, and 13 (22.8%) with 270°. The median age of onset was 5.7 years (range, 1–14 years) and the median duration of symptoms was 4.2 days (range, 0.5–5 days). Ultrasound showed low blood flow in 46 (80.8%) patients. The testis was retained in 41 (72.0%) patients and resected in 16 (28.0%). The testes appeared necrotic at 2 to 3 days after onset for patients with 270° torsion, appeared necrotic at 3 to 4 days after onset for those with 180° torsion, and were not necrotic at 4 to 5 days after onset for those with 90° torsion. The duration of symptoms in children decreased as the torsion angle increased.

Conclusion

Children with testicular torsion <360° are relatively young, while the duration of symptoms is relatively long. A high postoperative testicular survival rate is one of the clinical features in this study.

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

Objectives

To compare elastography measurements in men with normal testicular tissue, testicular microlithiasis and testicular cancer.

Methods

A total of 248 consecutive patients were included. All men provided written informed consent. Testicular stiffness was assessed using shear wave elastography (SWE). Three SWE velocity measurements were assessed in each testicle. The patients were divided into three groups; men with normal testicular tissue (n=130), men with testicular microlithiasis (n=99) and men with testicular cancer (n=19).

Results

We found a higher mean velocity in the group of patients with testicular cancer (1.92 m/s (95% CI 1.82-2.03)) compared to both the group with normal tissue (0.76 m/s (95% CI: 0.75-0.78)) (p<0.001) and the group with testicular microlithiasis 0.79 m/s (95% CI: 0.77-0.81) (p<0.001).

Conclusion

The presence of testicular microlithiasis increased stiffness slightly, but within the range of variation in normal testicles. Increased stiffness may indicate testicular malignancy in testicular lesions. Ultrasound elastography could be a very useful tool when investigating scrotum.

Comparison of shear wave velocities on ultrasound elastography between different machines, transducers, and acquisition depths: a phantom study

OBJECTIVES

To investigate consistency in shear wave velocities (SWVs) on ultrasound elastography using different machines, transducers and acquisition depths.

METHODS

The SWVs were measured using an elasticity phantom with a Young's modulus of 16.9 kPa, with three recently introduced ultrasound elastography machines (A, B and C from different vendors) and two transducers (low and high frequencies) at four depths (2, 3, 4 and 5 cm). Mean SWVs from 15 measurements and coefficient of variations (CVs) were compared between three machines, two transducers and four acquisition depths.

RESULTS

The SWVs using the high frequency transducer were not acquired at 5 cm depth in machine B, and a high frequency transducer was not available in machine C. The mean SWVs in the three machines were different (p ≤ 0.002). The CVs were 0-0.09 in three machines. The mean SWVs between the two transducers were different (p < 0.001) except at 4 and 5 cm depths in machine A. The SWVs were affected by the acquisition depths in all conditions (p < 0.001).

CONCLUSION

There is considerable difference in SWVs on ultrasound elastography depending on different machines, transducers and acquisition depths. Caution is needed when using the cutoff values of SWVs in different conditions.

KEY POINTS

• The shear wave velocities (SWVs) are different between different ultrasound elastography machines • The SWVs are also different between different transducers and acquisition depths • Caution is needed when using the cutoff SWVs measured under different conditions.