Stiffness of the Central Corpus Cavernosum on Shear-Wave Elastography Is Inversely Correlated with the Penile Rigidity Score in Patients with Erectile Dysfunction

The usefulness of shear wave elastography in evaluating erectile dysfunction severity before and after prostaglandin E1 test

Prostaglandin E1 intracavernous injection test is an established method for diagnosing erectile dysfunction. However, the evaluation is non-objective and often influenced by the evaluator's subjectivity. Herein, we measured and objectively evaluated shear wave elastography results of the corpus cavernosum before and after injection in 16 patients who underwent prostaglandin E1 testing. The response score of prostaglandin E1 tests were "1" in 2 cases, "2" in 2 cases, and "3" in 12 cases. The average transmission velocity before the injection and at the time of maximum erection after the injection were 2.21 m/s and 1.57 m/s, respectively. Transmission velocity decreased during erection in 14 of 16 cases (87.5%). The overall rate of change in transmission velocity due to injection was -26.7% and was significantly different between the poor (responses 1 and 2: -16.1%) and good erection (response 3: -30.2%) groups. To the best of our knowledge, this is the first attempt to evaluate erectile phenomenon using percutaneous ultrasonic elastography in Japan. Rate of change in shear wave transmission velocity due to prostaglandin E1 injection in the corpus cavernosum penis was associated with the degree of erection. Therefore, the rate of change in shear wave transmission velocity in the corpus cavernosum penis could be used as an objective index of erectile phenomenon. Percutaneous ultrasonic elastography is a non-invasive and useful test method for diagnosing erectile dysfunction, determining the therapeutic effect, and predicting prognosis.

Role of Shear Wave Elastography in the Diagnosis of Peyronie Disease

OBJECTIVES

The present study aims to explore the role of shear wave elastography (SWE) in the diagnosis of Peyronie disease (PD).

METHODS

A total of 59 PD patients and 59 age-matched healthy adult men were included in this study. The B-mode ultrasound (US) and SWE were performed for all subjects, and the Young modulus (YM) values of the corresponding regions of the penis in the PD and control groups were recorded and compared.

RESULTS

The mean age of the included PD patients and age-matched controls was 53.81 years (SD 9.52, range 32-73). On B-mode US evaluation, 41 (69.5%) of 59 included PD patients were found to have penile plaques, and the remaining 18 (30.5%) patients had no evidence of penile plaque. After evaluation using SWE, the YM values in the penile plaque region of these 41 patients with penile dysplasia were found to be significantly higher (60.29 kPa ± 19.95) than those outside the plaque (in the same patient) (21.05 kPa ± 4.58) and in the same penile region of the control group (20.59 kPa ± 4.65) (P < .001). In the remaining 18 PD patients, the results showed that the YM value of the abnormal penile region in the PD patients (56.67 kPa ± 13.52) was significantly higher than the YM value outside the abnormal penile region in the same patients (22.79 kPa ± 4.31) and in the same penile region in the control group (19.87 kPa ± 3.48) (P < .001; P < .001).

CONCLUSIONS

In conclusion, this study showed that SWE as a non-invasive technique is useful in identifying and differentiating penile plaques in PD patients and is a simple, rapid and complementary method to B-mode US.

Factors affecting the shear wave elastic quantitative measurement of penile tissue in rats

Background

As a new ultrasound technology, 2-dimensional shear wave elastography (2D-SWE) can evaluate the elastic characteristics of penile tissue. However, no studies have reported the main factors affecting the shear wave elastic quantitative measurement (SWQ) in penile tissue.

Objectives

To analyze the main factors affecting the SWQ reflecting the elastic characteristics of penile tissue by 2D-SWE.

Methods

Twenty healthy male Sprague-Dawley rats (5-60 weeks old) were selected for this study. We performed the 2D-SWE examination on the penis using the Aixplorer ultrasound system, with SWQ as the measurement index. We performed penile immunohistochemistry analysis with the positive area proportion (PAP) of alpha-smooth muscle actin (PAPS) and type III collagen fiber (PAPC) as the outcomes. Then, we conducted multiple linear regression analysis to explore the correlation of SWQ with PAPS and PAPC and established the regression equation.

Results

The multiple linear regression analysis showed that the linear regression equation (SWQ = 10.376 - 0.05 PAPS - 0.07 PAPC) was statistically significant (F = 21.153, P < 0.001). The content of smooth muscle cells (SMCs) and collagen fibers was negatively correlated with SWQ, affecting 42.6% of the total variation in SWQ (R2 = 0.426).

Conclusions

SMCs and collagen fibers are the main factors affecting the SWQ value of penile tissue and the primary tissue components determining the SWQ when using 2D-SWE to quantitatively evaluate the elastic characteristics of penile tissue.

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.

Assessment of the Rigidity Changes of Corpus Cavernosum Penis in Vasculary Erectile Dysfunction (ED) Subtypes by Shear Wave Elastography (SWE)

INTRODUCTION

Erectile dysfunction (ED) is a condition that is very common all over the world, concerns about men and causes very important social problems. The aim of this study is to perform quantitative penile corpus cavernosum (CC) stiffness measurements by using SWE for patients with both types of vascular ED.

METHODS

In our study, we handled the data of 101 participants in total. The average age of the participants was 56.36. We divided the participants after color Doppler US (CDUS) into three groups: normal group (n = 30), arterial insufficiency (n = 51), and venous insufficiency (n = 20). SWE measurements were made in both groups in the CC flaccid (f) and rigid (r) positions, and the results were noted. International Index of Erectile Function (IIEF-5) questionnaire and Erection score (ES) were evaluated.

RESULTS

The mean CC f SWE and r SWE measurement values were 20.2 ± 0.8 and 17.15 ± 0.54 kPa, 3.84 ± 0.13 and 2.78 ± 0.11 m/s in the arterial insufficiency group; 15.72 ± 0.58 and 12.52 ± 0.33 kPa, 2.88 ± 0.06 and 2.09 ± 0.11 m/s in the venous insufficiency group; 14.75 ± 0.51 and 13.41 ± 0.36 kPa, 2.63 ± 0.1 and 2.34 ± 0.11 m/s in the control group, respectively. The CC measurement of f SWE and r SWE values as kPa showed significant differences between the groups (P < .001).

CONCLUSION

SWE can provide quantitative data with high specificity and sensitivity while evaluating CC penile stiffness noninvasively. It seems to contribute to the radiological evaluation of ED cases with useful data.

Role of shear wave elastography (SWE) in erectile dysfunction patients for evaluation of daily tadalafil treatment outcome

The purpose of this study was to evaluate and anticipate the outcome of daily use of tadalafil in patients with erectile dysfunction using elastography. 183 volunteers and 183 patients with erectile dysfunction were included. Pretreatment SWE readings for our patients were calculated with a linear probe. IIEF score Q was measured once at the start of the study for volunteers and twice for patients, one prior to the start of tadalafil administration and the other on one year of 5 mg daily tadalafil after the second post-washout (one month post-treatment stopped). There was no significant difference between patients and volunteers in mean age or risk factors except in SWE values as mean SWE of volunteers was 14.03 ± 1.54 kpasc, while mean SWE of patients was 21.278 ± 8.228 kpasc. The presence of comorbid diabetes, severe disease and pre-SWE ≥23.635 was significantly associated with poor outcome. We conclude that penile SWE could be useful to select probable good responders for a continuous tadalafil use, thus avoiding the unnecessary cost and time in non-responders.