Role of Strain Elastography in the Evaluation of Testicular Torsion: An Experimental Study

A review of multiparametric ultrasound imaging in the clinical setting: scrotal contents

The innovative techniques in ultrasound have added a new dimension to investigating superficially located areas such as the contents of the scrotal sac. High frequency transducers, improved technology with the addition of elastography, contrast enhanced ultrasound and microvascular imaging has resulted in a further improvement in diagnostic capabilities. The ability to clearly demonstrate the presence or absence of vascularity within the area under investigation adds an additional dimension to operator confidence in establishing the presence of infarction, global or segmental, or the walls and cavity of an abscess in the testis or epididymis. Increased vascularity of a tumor aids the differential diagnosis based on the flow dynamics of the microbubble contrast, benign lesions likely to retain contrast. Elastography has the ability to ascertain the stiffness of tissue, and when used in conjunction with other ultrasound methods adds to the understanding of the likelihood of a malignant abnormality being present. All the different techniques come under the umbrella term 'multiparametric ultrasound', with the application in the scrotal sac detailed in this article.

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.

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.

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.

Estimating the time of onset of testicular torsion using ultrasonography in an experimental rat model

Purpose

We aimed to document the time of onset of ultrasonographic and histologic changes in the testes of a rat model following testicular torsion.

Methods

Twenty-five Sprague-Dawley rats were divided into four groups. All animals underwent preoperative Doppler ultrasonography. Groups 1, 2, and 3 underwent unilateral surgical torsion of the testis lasting for 72, 24, and 6 hours, respectively. Group 4 underwent a sham operation. The animals were followed with Doppler ultrasonography at 6, 24, 48, and 72 hours postoperatively. Histologic examinations were performed at the designated final time point for each group.

Results

After torsion, enlargement of the epididymal head and thickening of the spermatic cord over time were noted. Based on the ultrasonographic dimensions, the ratio of the epididymal volume increased with time following torsion (p=0.002). The torsed testes had an average weight gain of 0.27 g at 6 hours compared to the control testes, but an average weight loss of 0.22 g at 72 hours (P=0.006). Changes in testicular echotexture were noted as soon as 6 hours after torsion, but there was no consistent pattern of echotexture change thereafter. Histologically, viable tubules were seen 6 hours after torsion, while extensive hemorrhagic necrosis was found at 72 hours.

Conclusion

In evaluating testicular torsion, the enlargement ratio of the epididymis and thickening of the spermatic cord on Doppler ultrasonography may be useful for determining the urgency of immediate surgery. Changes in testicular echotexture may not be a reliable indicator of the time of onset.

Accuracy of real-time shear wave elastography in staging hepatic fibrosis: a meta-analysis

Background

Chronic liver disease (CLD) is an important cause of morbidity and mortality and can lead to hepatic fibrosis. This study was conducted to evaluate the diagnostic value of real-time shear wave elastography (SWE) in the assessment of hepatic fibrosis.

Methods

A systematic search of databases was performed for publications on SWE during the period between 2010 and 2017. The identified studies were analyzed using Meta-disc 1.4 software to integrate and analyze the data.

Results

Eleven studies comprising 1560 patients were included for analysis. The pooled sensitivity, specificity and diagnostic odds ratio were 0.85 (95% CI: 0.82–0.87), 0.79 (95% CI: 0.76–0.82) and 30.81 (95% CI: 16.55–57.34), respectively for patients with a Metavir-score of ≥ F2; 0.87 (95% CI: 0.84–0.91), 0.84 (95% CI: 0.82–0.87), 41.45 (95% CI:18.25–94.45), respectively for patients with ≥ F3; 0.88(95% CI: 0.83–0.91), 0.91 (95% CI: 0.89–0.92), 67.18 (95% CI:30.02–150.31), respectively for patients with ≥ F4. The areas under the receiver operating characteristic curve of the three groups were 0.9147, 0.9223 and 0.9520, respectively.

Conclusions

Our work demonstrates that SWE is highly accurate for detecting and staging hepatic fibrosis.

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.

Diagnostic Accuracy of Virtual Touch Quantification and Virtual Touch Imaging Quantification Sonoelastography Techniques in Pediatric Undescended Testes Patients

The purpose of this study was to determine the usefulness of virtual touch quantification (VTQ) and virtual touch imaging quantification (VTIQ) techniques for assessing undescended testes stiffness, by age and location. One testicle from each of 84 participants (31 of whom were healthy volunteers) was assessed by the point shear-wave elastography (p-SWE) method, using both VTQ and VTIQ techniques. The patients were grouped by location of assessment (intra-abdominal, inguinal, and scrotal) and age (group 1, healthy patients; group 2, patients age one and younger; and group 3, patients older than age one). Although the VTQ and VTIQ methods for group 2 showed similar results in the Bland-Altman plot, for group 3, the VTIQ method was more effective than the VTQ method. The use of p-SWE with VTIQ may be an appropriate technique for determining the tissue stiffness of testes located in the inguinal canal and for patients over one year of age.

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.

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.

Ultrasonography of pediatric urogenital emergencies: review of classic and new techniques

Urogenital emergencies are fairly common in the pediatric population, and a timely and correct diagnosis is necessary to avoid possible future infertility. In this field, ultrasonography is essential, as it has the advantages of being radiation-free and readily accessible. In particular, a high-frequency transducer allows precise evaluation of the morphology and vascularity of the scrotum, which is on the surface of the body. Beyond conventional techniques, new advanced imaging techniques have been developed, including elastography and contrast-enhanced ultrasonography. However, several pitfalls remain in the diagnosis of urogenital diseases using ultrasonography. Thus, accurate knowledge and sufficient experience with the technique are essential for making a correct diagnosis. This review provides an overview of pediatric urogenital emergency pathologies and recent ultrasonography techniques.