Shear wave elastography in erectile dysfunction

Could shear wave elastography (SWE) become a new radiologic approach to diagnose and differentiate erectile dysfunction (ED) from other potential pathologies? A research study conducted in Turkey shows evidence that SWE can provide valuable data in the radiologic assessment of ED patients and may provide additional data in the selection of treatment options.

Radiologists and urologists at the University of Health Sciences Istanbul Bakirkoy Dr. Sadi Konuk Training and Research Hospital conducted a comparative study of 70 men to determine the effectiveness of SWE in the diagnosis of ED and to discuss its potential contributions to the management of ED.

The patient cohort consisted of 35 healthy volunteers and 35 patients who experienced ED for 12 months or less and had a score of 17 or lower from the International Index of Erectile Function (IIEF) questionnaire. The men ranged from 39 to 71 years, with the mean age of patients with ED being 53 and healthy volunteers 54.

Each participant had a SWE examination in which they were asked to hold the glans penis gently and put the penile shaft on their pubic region. Measurements were performed from the middle portion of the penis with the probe held in a transverse plane, and the ROI circle was placed 1 cm deep on the corpus cavernosum penis. A total of five measurements were performed for each patient.

Lead author Rustu Turkay, MD, of the department of radiology, reported that the differences in the mean corpus cavernosum SWE measurement values were statistically significant. These values were 20.94 in the patient group and 24.63 in the control group. The authors calculated a cut-off value using ROC analysis. Using a cut-off value of 17.1 kPa to determine the presence of ED, they also calculated sensitivity (94.29%), specificity (34.29%), PPV (85.71%), and NPV (58.93%). This cut-off value for the corpus cavernosum SWE measurement showed statistically significant association with ED.

Compared to Doppler ultrasonography, the current imaging modality of choice for case of ED that require thorough investigation and determination of treatment methods, SWE, which measures tissue stiffness quantitatively, is a rapid and practical radiological method. In their article published in Ultrasound, the authors cited several published studies and case reports in which SWE was used to image the penis. To their knowledge, no published research exists explaining how ED may alter SWE measurement values in humans. They hypothesize that the disease and the length of its duration may affect the proportion of smooth muscle cells and collagen in the tissue, and that decreased SWE measurement differences may be caused by the change in the amount of collagen, despite the reduction in the number of smooth muscle cells.

The authors continue to research the use of SWE in penile imaging. In an unrelated study published in the European Journal of Radiology, they investigated the change of rigidity of the penis with age in a group of healthy volunteers ranging from 20 to 71 years.¹ The authors recommend that additional research studies be conducted to further investigate and validate the use of SWE in the diagnosis and treatment planning for ED.

REFERENCES

1. Inci E, Turkay R, Nalbant MO, et al. The value of shear wave elastography in the quantification of corpus cavernosum penis rigidity and its alteration with age. Eur J Radiol. 89; 4: 106-110.
2. Turkay R, Inci E, Yenice MG, et al. Shear wave elastography: Can it be a new radiologic approach for the diagnosis of erectile dysfunction. Ultrasound. Published online January 1, 2017.