madman
Super Moderator
Abstract
Background: Because it is a superficial structure, the penis is ideally suited to ultrasound imaging. A number of disease processes, including Peyronie’s disease, penile fractures, and tumors, are clearly visualized with ultrasound. Baseline and dynamic assessment of cavernosal arterial changes after pharmaco-stimulation with alprostadil allows standardized diagnosis of arterial and venogenic causes of erectile dysfunction (ED).
Objective: to illustrate how to correctly perform flaccid and dynamic penile duplex ultrasound (D-PDU) and in which patients to recommend it.
Materials/Methods: An extensive search of the literature was carried out on Pubmed with the insertion of the following Medical Subjects Headings (MeSH) terms and keywords "penile color Doppler ultrasound" "peak systolic velocity" "end-diastolic velocity", "acceleration time", "resistance index”.
Evidence: In our experience, arterial erectile dysfunction is identified after standardized intracavernous injection (ICI) of alprostadil (10 mcg) when values of peak systolic velocity (PSV) are <35 cm/sec and, in the most severe forms, for values <25 cm/sec. Arterial insufficiency can also be identified by increased acceleration time (AT) values (>110 msec) and/or by a lack of visualization of helicine arteries at power doppler mode along with the incomplete achievement of penile rigidity. The veno-occlusive incompetence is determined when end-diastolic velocity (EDV) values are > 4.5-5 cm/sec or in the case of resistance index (RI) values <0.75. The assessment of additional surrogate markers of endothelial dysfunction, i.e. intima-media thickness, mean platelet volume (MPV), endothelial progenitor cells (EPC), endothelial cell-specific molecule-1(endocan) is also useful in assessing the patient's cardiovascular risk but is still considered investigational in the interpretation of D-PDU results.
Conclusion: D-PDU scan after ICI with vasoactive drugs is a safe procedure and represents the gold standard for the diagnostics of penile pathologies and should be performed in men with ED not responding to oral conventional therapies and/or in those requiring accurate stratification of cardiovascular risk.
1. Introduction
Penile anatomical pathology is a frequent cause of erectile dysfunction (ED) and penile blood flow studies are important in discriminating vascular incompetence that is relevant for the patient (1). Arteriopathy causes ED through a decrease of blood flow in the penile arteries; also, vascular impairments when associated with alteration of cavernous smooth muscle cells, represent the major cause of ED in men over 50. Atherosclerosis may be considered the most important disease linked to ED and Leriche’s syndrome, defined by aortic-iliac atherosclerosis along with “claudication-intermittens” (2). Dyslipidemia, hypertension, diabetes mellitus, obesity, smoking, and sedentary lifestyle should be considered as independent risk factors for atherosclerosis and consequently, may contribute to the pathogenesis of ED (3). Moreover, if present in combination with each other, they may influence the severity of DE leading to less or more severe forms (4). High-resolution grey-scale imaging, especially in combination with color and pulsed-wave Doppler, forms the basis of modern penile ultrasound evaluation. In this pictorial review, we will summarize the state-of-the-art regarding the most appropriate technique for dynamic- Penile duplex ultrasound (D-PDU), analysis of the spectral Doppler waveform, and different imaging related to most common normal and pathological cases in clinical practice.
3. Technique
4. Ponderated analysis of the spectral Doppler waveform
4.1 Qualitative analysis
4.2 Quantitative analysis
5. Dynamic penile duplex ultrasound: normal patterns
5.1 Grey-scale ultrasound
5.2 Color Doppler
5.3 Power Doppler
5.4 Pulsed Doppler
6. Dynamic penile duplex ultrasound: correlation with other markers of endothelial dysfunction
7. Conclusions
D-PDU is an important diagnostic tool even in the era of oral drugs. We believe that the D-PDU has a fundamental diagnostic role even in the young patient with primary ED or secondary to trauma of the pelvis, perineum, and penis. Remarkably, young patients with severe anxiety show a “late-responder” penile hemodynamic pattern. In these patients, although PSV in the flaccid state may be below 13 cm/s, a normal PSV value (>35 cm/s) may be reached late (20 min) after ICI. Therefore, a D-PDU scan after ICI with vasoactive drugs should be considered a safe and accurate diagnostic test in patients with ED of any origin, while PSV in the flaccid state may not be able to investigate between different causes of vascular ED. Also, the importance of recognizing the etiology of ED has must be reinforced even in the elderly (48). In this regard, we want to remember how performing a D-PDU before the prescription of oral drugs can often be a predictor of their effectiveness (49). In fact, the data indicate that there is a correlation between the nature and severity of penile vascular damage and the response to oral drugs such as sildenafil, with a lower response observed in the presence of severe venous occlusive dysfunction or mixed ED (50).
*Finally, we want to emphasize that ED can be the first sentinel symptom for patients at vascular risk (51). The correct performance of a D-PDU is able to recognize various forms of arterial ED (52) and may be mandatory for patients’ referral to the most inclusive morphological examination of the aorta, iliac vessels, femoral and carotid bifurcations, coronary arteries in search of lesions unrecognized that could save the patient's life.
Background: Because it is a superficial structure, the penis is ideally suited to ultrasound imaging. A number of disease processes, including Peyronie’s disease, penile fractures, and tumors, are clearly visualized with ultrasound. Baseline and dynamic assessment of cavernosal arterial changes after pharmaco-stimulation with alprostadil allows standardized diagnosis of arterial and venogenic causes of erectile dysfunction (ED).
Objective: to illustrate how to correctly perform flaccid and dynamic penile duplex ultrasound (D-PDU) and in which patients to recommend it.
Materials/Methods: An extensive search of the literature was carried out on Pubmed with the insertion of the following Medical Subjects Headings (MeSH) terms and keywords "penile color Doppler ultrasound" "peak systolic velocity" "end-diastolic velocity", "acceleration time", "resistance index”.
Evidence: In our experience, arterial erectile dysfunction is identified after standardized intracavernous injection (ICI) of alprostadil (10 mcg) when values of peak systolic velocity (PSV) are <35 cm/sec and, in the most severe forms, for values <25 cm/sec. Arterial insufficiency can also be identified by increased acceleration time (AT) values (>110 msec) and/or by a lack of visualization of helicine arteries at power doppler mode along with the incomplete achievement of penile rigidity. The veno-occlusive incompetence is determined when end-diastolic velocity (EDV) values are > 4.5-5 cm/sec or in the case of resistance index (RI) values <0.75. The assessment of additional surrogate markers of endothelial dysfunction, i.e. intima-media thickness, mean platelet volume (MPV), endothelial progenitor cells (EPC), endothelial cell-specific molecule-1(endocan) is also useful in assessing the patient's cardiovascular risk but is still considered investigational in the interpretation of D-PDU results.
Conclusion: D-PDU scan after ICI with vasoactive drugs is a safe procedure and represents the gold standard for the diagnostics of penile pathologies and should be performed in men with ED not responding to oral conventional therapies and/or in those requiring accurate stratification of cardiovascular risk.
1. Introduction
Penile anatomical pathology is a frequent cause of erectile dysfunction (ED) and penile blood flow studies are important in discriminating vascular incompetence that is relevant for the patient (1). Arteriopathy causes ED through a decrease of blood flow in the penile arteries; also, vascular impairments when associated with alteration of cavernous smooth muscle cells, represent the major cause of ED in men over 50. Atherosclerosis may be considered the most important disease linked to ED and Leriche’s syndrome, defined by aortic-iliac atherosclerosis along with “claudication-intermittens” (2). Dyslipidemia, hypertension, diabetes mellitus, obesity, smoking, and sedentary lifestyle should be considered as independent risk factors for atherosclerosis and consequently, may contribute to the pathogenesis of ED (3). Moreover, if present in combination with each other, they may influence the severity of DE leading to less or more severe forms (4). High-resolution grey-scale imaging, especially in combination with color and pulsed-wave Doppler, forms the basis of modern penile ultrasound evaluation. In this pictorial review, we will summarize the state-of-the-art regarding the most appropriate technique for dynamic- Penile duplex ultrasound (D-PDU), analysis of the spectral Doppler waveform, and different imaging related to most common normal and pathological cases in clinical practice.
3. Technique
4. Ponderated analysis of the spectral Doppler waveform
4.1 Qualitative analysis
4.2 Quantitative analysis
5. Dynamic penile duplex ultrasound: normal patterns
5.1 Grey-scale ultrasound
5.2 Color Doppler
5.3 Power Doppler
5.4 Pulsed Doppler
6. Dynamic penile duplex ultrasound: correlation with other markers of endothelial dysfunction
7. Conclusions
D-PDU is an important diagnostic tool even in the era of oral drugs. We believe that the D-PDU has a fundamental diagnostic role even in the young patient with primary ED or secondary to trauma of the pelvis, perineum, and penis. Remarkably, young patients with severe anxiety show a “late-responder” penile hemodynamic pattern. In these patients, although PSV in the flaccid state may be below 13 cm/s, a normal PSV value (>35 cm/s) may be reached late (20 min) after ICI. Therefore, a D-PDU scan after ICI with vasoactive drugs should be considered a safe and accurate diagnostic test in patients with ED of any origin, while PSV in the flaccid state may not be able to investigate between different causes of vascular ED. Also, the importance of recognizing the etiology of ED has must be reinforced even in the elderly (48). In this regard, we want to remember how performing a D-PDU before the prescription of oral drugs can often be a predictor of their effectiveness (49). In fact, the data indicate that there is a correlation between the nature and severity of penile vascular damage and the response to oral drugs such as sildenafil, with a lower response observed in the presence of severe venous occlusive dysfunction or mixed ED (50).
*Finally, we want to emphasize that ED can be the first sentinel symptom for patients at vascular risk (51). The correct performance of a D-PDU is able to recognize various forms of arterial ED (52) and may be mandatory for patients’ referral to the most inclusive morphological examination of the aorta, iliac vessels, femoral and carotid bifurcations, coronary arteries in search of lesions unrecognized that could save the patient's life.
