Erectile dysfunction: the role of penile Doppler ultrasound in diagnosis

음경 응급 상황-초음파 영상의 스펙트럼 이해

Penile emergencies are uncommon and can be categorized as having infectious, vascular, traumatic, or multifactorial etiologies. To facilitate early diagnosis and treatment during emergency, US and color Doppler imaging are imperative. US depicts hypoechoic collections regardless of the presence of air foci in infections like abscess and Fournier's gangrene. Color Doppler imaging is conducted to evaluate vascular conditions such as penile Mondor disease (PMD) and priapism. PMD is indicated by the absence of color flow and non-compressibility of dorsal penile vein. Priapism can be categorized based on cavernosal artery flow: high flow and low flow. In traumatic injuries like penile fracture, US reveals breach in tunica albuginea with hematoma. Peyronie's disease can be multifactorial in origin and the imaging is commonly visualized as thickening of the tunica albuginea and echogenic calcified plaques. Urethral injuries are urethral discontinuity with adjacent collection. Urethral calculus is visualized as echogenic focus with posterior acoustic shadowing. Therefore, effective collaboration between radiologists and urologists is required for appropriate initial diagnosis and prompt treatment.

Penile Evaluation: An Illustrated Review

ABSTRACT

High-frequency ultrasound is the imaging modality of choice for evaluating penile pathology because of its easy access, low cost, and patient tolerance ( The Penis, Diagnostic Ultrasound, second edtion . Boca Raton: CRC Press; 2007:957-978). This pictorial review will illustrate the sonographic features of emergent and nonemergent penile conditions such as penile fracture, spongial tear, urethral injury, various types of priapism, erectile dysfunction, penile abscess, and Mondor disease.

Therapeutic outcomes and analysis of Doppler findings in 25 patients with non-ischemic priapism

Non-ischemic priapism (NiP) is painless partial tumescence caused by genital trauma and the formation of intracorporal arterio-venous fistula. This is a retrospective study of 25 men with NiP and reports the long-term erectile function and colour doppler ultrasound (CDUS) findings after treatment for NiP. Unstimulated CDUS was performed at diagnosis, 1 week and at last follow-up after treatment. CDUS traces were analysed: peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI) and mean velocity (MV) were calculated. Erectile function was assessed using the IIEF-EF questionnaire. At the last follow-up (median 24 months), 16 men had normal erectile function (64%): median IIEF-EF score 29 (IQR 28.5-30; σ2 2.78) and nine had erectile dysfunction (36%): median IIEF-EF score 17 (IQR 14-22; σ2 33.6). MV and EDV were statistically higher in those patients with erectile dysfunction at last follow-up compared to patients with normal erectile function: median MV 5.3 cm/s (IQR 2.4-10.5 cm/s; σ2 34) vs 2.95 cm/s (IQR 1.03-3.95; σ2 3.4) p < 0.002 and median EDV 4.0 cm/s (IQR 1.5-8.0; σ2 14.7) vs 0 cm/s (IQR 0-1.75; σ2 2.21) p < 0.004. Erectile dysfunction was observed in 36% of men treated for NiP and was associated with abnormal low resistance resting CDUS waveforms. Further investigation for persistent arteriovenous fistulation should be considered in these patients.

Imaging in Male Infertility

Infertility is defined as inability to conceive despite regular unprotected sexual intercourse for greater than 1 year. Conditions involving the male partner accounts for the infertility in approximately 50% of cases. The goals of imaging in male infertility are to detect treatable/ reversible causes, imaging for sperm retrieval from testis or epididymis for assisted reproductive techniques like in vitro fertilization or intracytoplasmic sperm injection and to provide appropriate genetic counselling for prevention of occurrence of disease in future offspring. The purpose of this article is to describe imaging features in various causes of male infertility to acquaint radiologists with various imaging appearances of causes of male infertility to avoid missing these pathologies.

Comparison of preoperative penile elastographic ultrasound findings and pathological tissue results of patients implemented with penile prosthesis

OBJECTIVE

Histopathological analysis of the relationship between penile elastography and erectile dysfunction.

MATERIAL AND METHOD

12 patients who applied to our clinic for erectile dysfunction in the last 1 year and accepted this study were included. Preoperative two-dimensional shear wave elastography imaging was performed in 12 patients and recorded in the Pascal (kPa) unit. Approximately 0.5 × 0.5 × 0.5 cm tissue samples were taken from the right and left cavernous tissue during penile prosthesis implantation operation. Tissue samples were sent to the pathology department. The percentage of the area covered by muscle fibers and elastic fibers in the corpus cavernosum was noted semi-quantitatively (ratio of muscle fibers and cavernous body elastic fiber score). All data obtained were compared with each other.

RESULTS

Cavernous body elastic fiber score data(Grouped Score 1, 2 and 3) and percentage of cavernous body muscle fibers data (Grouped %10, %20, %30… %100) were compared with Shear wave elastography data (kPa). The results were not statistically significant according to the Kruskal Wallis Test. Cavernous body elastic fiber score and the percentage of cavernous body muscle fibers were also compared, it was not statistically significant according to the Kruskal Wallis test and Spearman's correlation test.

CONCLUSIONS

Penile shear wave elastography can be used clinically to quantitatively assess the amount of smooth muscle cells and elastic fibers in the penis, but it deserves to be studied with a larger number of patients and a more specific interpretation of the pathology preparation.

The flow index provides a comprehensive assessment of erectile dysfunction by combining blood flow velocity and vascular diameter

Dynamic duplex sonography (DUS) is not comprehensive in the evaluation of arteriogenic erectile dysfunction (ED). We introduced a new parameter, the flow index (FI), into the assessment of arteriogenic ED. A retrospective review of a prospective database was conducted. Patients undergoing DUS and pelvic computed tomography angiography for the evaluation of ED were included. The FI was calculated from peak systolic velocity (PSV) and the percentages of pelvic arterial (PLA) stenosis. Correlations between PSV, PLA stenosis, the FI, and erectile function were calculated. Eighty-three patients were included. Compared with PSV, the FI had better correlations with the erection hardness score (EHS) (r_s = 0.405, P < 0.001 for FI; r_s = 0.294, P = 0.007 for PSV). For EHS < 3, the areas under the ROC curve of FI and PSV were 0.759 and 0.700, respectively. In patients with normal DUS but EHS < 3, PLA stenosis was more severe (62.5% vs. 10.0%, P = 0.015), and the FI was lower (8.35 vs. 57.78, P = 0.006), while PSV was not different. The FI is better than PSV in the evaluation of arteriogenic ED. On the other hand, assessment of the pelvic arterial system should be included in the evaluation of ED.

Current Techniques for the Objective Measures of Erectile Hardness

INTRODUCTION

One of the most discussed topics in the urology provider's office is that of the male penile erection. Moreover, this is also a frequent basis for consultation by primary care practitioners. As such, it is essential that urologists are familiar with the various means by which the male erection may be evaluated.

OBJECTIVES

This article describes several techniques presently available that may serve to objectively quantify the rigidity and hardness of the male erection. These techniques are meant to bolster information gathered from the patient interview and physical examination to better guide patient management.

METHODS

An extensive literature review was performed examining publications in PubMed on this subject, including corresponding contextual literature.

RESULTS

While validated patient questionnaires have been routinely employed, the urologist has many additional means available to uncover the extent of the patient's pathology. Many of these tools are noninvasive techniques that involve virtually no risk to the patient and take advantage of pre-existing physiologic properties of the phallus and its blood supply to estimate corresponding tissue stiffness. Specifically, Virtual Touch Tissue Quantification which precisely quantifies axial and radial rigidity, can provide continuous data on how these forces change over time, thus providing a promising comprehensive assessment.

CONCLUSION

Quantification of the erection allows for the patient and provider to assess response to therapy, aids the surgeon in choice of appropriate procedure, and guides effective patient counseling regarding expectation management. Rohrer GE, Premo H, Lentz AC. Current Techniques for the Objective Measures of Erectile Hardness. Sex Med Rev 2022;XX:XXX-XXX.

Application of Superb Microvascular Imaging in the Diagnosis of Vascular Erectile Dysfunction

To compare the difference between superb microvascular imaging (SMI) and color doppler flow imaging (CDFI) on vascular grading and blood flow display rate of the penile cavernous artery of vascular erectile dysfunction (ED), and to evaluate the length of time to obtain blood flow spectrum. 68 patients with ED were preformed for the examination of SMI and CDFI. The difference between the two techniques on vascular grading and blood flow display rate were compared. Hemodynamic parameters, namely peak systolic velocity (PSV), end diastolic velocity (EDV), and resistant index (RI) and the length of time obtained blood flow spectrum were compared. SMI was more sensitive to assess vascular grading and blood flow display rate than CDFI (P < 0.05). Hemodynamic parameters (PSV, EDV, and RI) measured by SMI and CDFI were well correlated (r = 0.981, P < 0.001; r = 0.879, P < 0.001; r = 0.937, P < 0.001). The duration of time necessary obtained the spectrums of grade 3 and grade 4 blood flow was shorter than that of grade 1 and grade 2, and SMI was comparatively shorter than CDFI (P < 0.05). In conclusion, SMI detected the blood flow of the penile cavernous artery better and maked the examination time shorter than CDFI, which can be considered as a more effective technique to diagnose vascular ED.

Erectile dysfunction in patients undergoing multiple attempts at hypospadias repair: Etiologies and concerns

INTRODUCTION

One-third of adult patients presenting for the repair of persistent penile defects after failing multiple hypospadias repair attempts during childhood will complain of erectile dysfunction (ED). The goal of this paper is to identify possible etiological causes of its onset.

MATERIALS AND METHODS

Five selection criteria were used for entrance into the study: 1) Patients had to have failed ≥ three prior hypospadias repair attempts. 2) Present for evaluation between 18 and 40 years of age. 3) No known congenital or medical anomaly could be present that could have predisposed to erectile dysfunction. 4) Sexual history inventory for men (SHIM-5 score) completed. 5) All patients with moderate to severe ED (SHIM scores ≤ 16) underwent psychological screening; individuals with good quality spontaneous or self-stimulated erections, experiencing major life events, or had documented psychological problems were excluded from the study. One hundred consecutive patients meeting these criteria were assessed. We evaluated multiple factors to discern if they were associated with the onset of ED: the initial location of the urethral meatus, if a corporoplasty was performed, the type of corporoplasty used, if the urethral plate was divided or resected, the use of a ventral corporal graft, the total number of open reparative procedures performed before referral, the number of direct visual internal urethrotomies (DVIU) performed, the length of a urethral stricture at the time of the referral and whether lichen sclerosus was present. Statistical evaluations used chi-square analysis, two-tailed t-tests, or a logistic regression model where indicated, p-values < 0.05 were considered significant.

RESULTS

37% (37/100) of our patients complained of moderate to severe ED (SHIM score ≤16). Statistical analysis comparing patients with ED to those without ED (63%:63/100), revealed patients with ED were older, median age 34 yrs (range 20-40) vs 26 yrs (range 18-40) p = 0.0212, had undergone division of the urethral plate 70.3% (26/37) vs 47.6% (30/63), p = 0.0276, had placement of a ventral corporal graft, 24% (8/33) vs 1.5% (1/67), p = 0.0003 or had undergone repetitive DVIU's to manage urethral stricture disease, median number 4 (range 0-15) vs 0 (range 0-6), p < 0.0001, see table.

CONCLUSIONS

The early onset of ED in patients that failed multiple attempts at hypospadias repair in childhood is associated with advancing age, division of the urethral plate, and prior ventral corporal grafting. Especially significant is the association of ED to the use of repetitive internal urethrotomy to manage urethral stricture disease.

A novel method for hemodynamic analysis of penile erection

Measurement of blood flow velocity through the cavernosal arteries via penile color Doppler ultrasound (PDUS) is the most common objective method for the assessment of erectile function. However, in some clinical cases, this method needs to be augmented via the invasive intracavernosal pressure (ICP) measurement, which is arguably a more direct index for erectile function. The aim of this study is to develop a lumped parameter model (LPM) of the penile circulation mechanism integrated to a pulsatile, patient-specific, bi-ventricular circulation system to estimate ICP values non-invasively. PDUS data obtained from four random patients with erectile dysfunction are used to develop patient-specific LPMs. Cardiac output is estimated from the body surface area. Systemic pressure is obtained by a sphygmomanometer. Through the appropriate parameter set determined by optimization, patient-specific ICP values are predicted with only using PDUS data and validated by pre- and post-papaverine injection cavernosometry measurements. The developed model predicts the ICP with an average error value of 3 mmHg for both phases. Penile size change during erection is predicted with a ~15% error, according to the clinical size measurements. The developed mathematical model has the potential to be used as an effective non-invasive tool in erectile function evaluation, expanding the existing clinical decision parameters significantly.

Effect of Intracavernosal Injection of Prostaglandin E1 on Duration and Rigidity of Erection in Patients With Vasculogenic Erectile Dysfunction: Is It Dose Dependent?

OBJECTIVE

To assess if the effect of intracavernosal injection of prostaglandin E1 (PGE1) on duration and rigidity of erection is dose dependent in patients with different types of vasculogenic erectile dysfunction (ED)?

METHODS

A hundred patients with ED were assigned into 4 groups (n = 25/each); group (A) patients with arteriogenic ED, group (B) patients with veno-occlusive ED, group (C) patients with mixed (arteriogenic and veno-occlusive) ED, and group (D) patients who have only psychogenic ED (control). After intracavernosal injection of PGE1, patients were assessed using penile Doppler ultrasonography and erection hardness score together with calculation of erection duration. The starting dose of PGE1 was 5 μg which was increased to 10 µg and 20 µg as a maximal dose when needed.

RESULTS

The mean PSV of patients in groups A, B, C, and D were 24.38 ± 3.3, 37.74 ± 8.28, 22.24 ± 3.85, and 47.76 ± 6.27, respectively. In group D, 88% have achieved the best response at dose of 5 µg while 5.3%, 21.7%, and 0% have achieved the best response at dose of 5 µg in groups A, B, and C, respectively (P < .05 for each). The rest of patients have required either 10 or 20µg to achieve the best response. Patients in group C have required the highest dose of PGE1 to achieve the best response (P < .05).

CONCLUSION

Intracavernosal injection of PGE1 in escalating doses have improved the rigidity and duration of erection in patients with different types of vasculogenic ED. Patients with mixed arteriogenic and veno-occlusive ED have required the highest dose of PGE1 to achieve the best response.

Imaging Modalities in Genitourinary Emergencies

Emergency physicians rely on a multitude of different imaging modalities in the diagnosis of genitourinary emergencies. There are many considerations to be taken into account when deciding which imaging modality should be used first, as oftentimes several diagnostic tools can be used for the same pathologic condition. These factors include radiation exposure, sensitivity, specificity, age of patient, availability of resources, cost, and timeliness of completion. In this review, the strengths and weaknesses of different imaging tools in the evaluation of genitourinary emergencies are discussed.

Association between penile dynamic contrast-enhanced MRI-derived quantitative parameters and self-reported sexual function in patients with newly diagnosed prostate cancer

INTRODUCTION

The high incidence of prostate cancer, coupled with excellent prostate cancer control rates, has resulted in growing interest in nononcological survivorship issues such as sexual function. Multiparametric magnetic resonance imaging (MRI) is increasingly being performed for local staging of prostate cancer, and due to the close anatomical relationship to the prostate, penile enhancement is often depicted in prostate MRI.

AIM

To evaluate the associations between quantitative perfusion-related parameters derived from dynamic contrast-enhanced (DCE)-MRI of the penis and self-reported sexual function in patients with newly diagnosed prostate cancer.

METHODS

This retrospective study included 50 patients who underwent DCE-MRI for prostate cancer staging before prostatectomy. The following perfusion-related parameters were calculated: volume transfer constant (K(trans)), rate constant (k(ep)), extracellular-extravascular volume fraction (v(e)), contrast enhancement ratio (CER), area under the gadolinium curve after 180 seconds (AUC180), and slope of the time/signal intensity curve of the corpora cavernosa. Associations between perfusion-related parameters and self-reported sexual function were evaluated using the Wilcoxon Rank-Sum test.

MAIN OUTCOME MEASURES

Patient responses to the sexual function domain of the Prostate Quality of Life survey.

RESULTS

Five of the six DCE-MRI parameters (K(trans), v(e), CER, AUC180, and slope) were significantly associated with the overall score from the sexual domain of the survey (P = 0.0020-0.0252). CER, AUC180, and slope were significantly associated with the answers to all six questions (P = 0.0020-0.0483), ve was significantly associated with the answers to five of six questions (P = 0.0036-0.1029), and K(trans) was significantly associated with the answers to three of six questions (P = 0.0252-0.1023). k(ep) was not significantly associated with the overall survey score (P = 0.7665) or the answers to any individual questions (P = 0.4885-0.8073).

CONCLUSION

Penile DCE-MRI parameters were significantly associated with self-reported sexual function in patients with prostate cancer. These parameters are readily available when performing prostate MRI for staging and may be relevant to the management of patients considering prostate cancer therapies.

Office-based management of impotence and Peyronie's disease

Erectile dysfunction (ED) impacts more than 50% of men older than 40 years; Peyronie disease (PD) affects up to 10% of men, with an adverse impact on normal sexual function and overall well-being. ED can also be the first sign of other underlying disease. The office-based evaluation of ED and PD is the first step in the management of these devastating conditions of men's health. New and exciting nonsurgical therapies are now available to help treat these conditions and restore sexual function and quality of life.

Priapism: pathophysiology and the role of the radiologist

Priapism is defined as a penile erection that persists for 4 h or longer and is unrelated to sexual activity. Its identification is important as lack of timely treatment (particularly of the low flow/ischaemic subgroup) can result in persisting erectile dysfunction as a consequence of irreversible corporal fibrosis. This review describes the physiology and anatomy of the normal erection, the aetiology and pathophysiology of the different types of priapism, and the role of the radiologist in the management of the condition. The treatment of iatrogenic priapism following intracavernosal injection of pharmacostimulant is discussed.

Male infertility: the role of imaging in diagnosis and management

The investigation of male infertility is assuming greater importance, with male factors implicated as a causal factor in up to half of infertile couples. Following routine history, examination and blood tests, imaging is frequently utilised in order to assess the scrotal contents for testicular volume and morphology. Additionally, this may give indirect evidence of the presence of possible reversible pathology in the form of obstructive azoospermia. Further imaging in the form of transrectal ultrasound and MRI is then often able to categorise the level of obstruction and facilitate treatment planning without resort to more invasive imaging such as vasography. Ultrasound guidance of therapy such as sperm or cyst aspiration and vasal cannulation may also be performed. This article reviews the imaging modalities used in the investigation of male infertility, and illustrates normal and abnormal findings that may be demonstrated.

Predictive Value of Penile Dynamic Colour Duplex Doppler Ultrasound Parameters in Patients with Post-Traumatic Urethral Stricture

This study evaluated dynamic colour duplex Doppler ultrasound (D-CDDU) for the assessment of erectile function in patients with post-traumatic urethral stricture. In total, 44 patients with urethral stricture secondary to trauma were recruited between January 2009 and June 2010. Peak systolic velocity of the cavernosal artery was measured before and after intracavernosal injection (ICI) of 20 mg papaverine and 1 mg phentolamine. Cavernosal artery end-diastolic velocity and resistance index (RI) were evaluated after ICI. Patients with RI ≥ 0.8 had significantly shorter strictures than those with RI < 0.8 after ICI only in cases of posterior urethral stricture. Patients with RI ≥ 0.8 were significantly younger than those with RI < 0.8. Urethral stricture length was negatively correlated with RI ( r = −0.375). Cavernosal artery RI after ICI is a reliable predictor of erectile function in patients with urethral stricture, especially posterior stricture. The patient's age should be considered when using this parameter.

Penile arterial waveform analyzer for assessing penile vascular function in young adults

Not only does erectile dysfunction (ED) reflect penile vascular disorder in the majority of patients, but it also implicates their high systemic cardiovascular risk. Based on the principle of reactive hyperemia after a brief period of penile ischemia, in this study, we tested the validity of a new Penile Arterial Waveform Analyzer (PAWA) in assessing the relative increase in post-ischemic penile perfusion. Twenty young adult males (mean age 24.24 ± 2.45) without known history of cardiovascular diseases were recruited, whose anthropometric characteristics were recorded and their serum testosterone levels as well as biochemical profiles were determined. A penile cuff was applied to each subject, with cuff pressure being increased from 80 to 250 mmHg, each for 4 min, followed by reperfusion for 7 min. By dividing the area under waveform contour of hyperemic and baseline signals after Ensemble Empirical Mode Decomposition (EEMD), a Penile Perfusion Index (PPI) was calculated. Penile Brachial Index (PBI) was also obtained for comparison. The results not only showed a significant agreement between PPI and serum testosterone levels, but also a superiority of PPI to PBI in distinguishing the high- and low-risk groups for potential ED (PPI: p = 0.039 vs. PBI: p = 0.147). PPI was also demonstrated to show significant correlations with waist circumference (p < 0.001), body mass index (p = 0.005), body weight, total triglyceride, high-density lipoprotein, and systolic and diastolic pressures (all p < 0.05). In conclusion, we proposed a portable and easy-to-operate system in assessing the relative increase in penile perfusion after brief ischemia. The PPI thus obtained correlated significantly with serum testosterone levels as well as key anthropometric and serum biochemical parameters even in apparently healthy young adults, suggesting its potential as a sensitive tool in monitoring penile vascular function and risk for ED.