High-frequency ultrasound for penile evaluation in ED diagnosis

[madman]

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 edition. 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.




Ultrasound is the first-line imaging modality in the evaluation of penile pathology. Although uncommon, penile trauma and vascular emergencies require a prompt diagnosis to guide appropriate management and should be considered an emergency. Patients may seek an emergent evaluation with minor injuries, and diagnostic assessment must distinguish acute from nonacute pathologies.1 This can be challenging because of the presence of overlapping sonographic features. This pictorial review will illustrate the ultrasound findings of various penile pathologies, including penile fracture, post traumatic or postsurgical changes in the absence of fracture, and low- and high-flow priapism. Typical results of erectile dysfunction will also be reviewed.




*PENILE ANATOMY

*SONOGRAPHIC TECHNIQUE

*PENILE TRAUMA
-Penile Fracture

*Mimic of Penile Fracture
-Post–Collagenase Treatment of Peyronie Disease
-Intracavernosal Hematoma Without Penile Fracture
-Corpora Spongiosal Hematoma
-Urethral Rupture

*Infections
-Penile Abscess

*Penile Abscess Mimics
-Penile Prosthesis Explant

*Vascular Diseases
-Low-Flow Priapism
-High-Flow Priapism
-Mondor Disease
-Erectile Dysfunction




Erection Physiology

The penile artery is a branch of the internal pudendal artery, and it trifurcates into the dorsal penile artery, cavernosal artery, and bulbourethral artery.20,21 The excitement of the parasympathetic nervous system releases nitrous oxide, which results in vasodilation of the cavernosal penile arteries and their helical branches. Vasodilation of these vessels results in swelling of the corpus cavernosum and collapse of the penile veins. There are 2 prominent penile veins, both running along the dorsal aspect of the penis, the superficial dorsal vein and the deep dorsal vein. There are 4 stages of erection: flaccid state, filling phase, tumescent phase, and rigid phase (Table 2, Fig. 11).


-Imaging Protocol
-Arterial Inflow Disease
-Venous Leakage
-Peyronie Disease




CONCLUSIONS

In summary, penile ultrasound has many applications. The portability and ease of rapid image acquisition and assessment make ultrasound the imaging modality for the initial evaluation of penile pathology. This pictorial review highlights some key sonographic findings that can direct surgical or nonsurgical management in the acute setting and the pertinent findings in characterizing nonemergent pathology such as erectile dysfunction.

 

[madman]

FIGURE 1. A, The penis consists of 2 corpora cavernosa (asterisk) and 1 corpus spongiosum (arrow head). The corpus cavernosum issurrounded by the tunica albuginea (arrow). B, Line drawing demonstrating detailed penile anatomy.

 

[madman]

FIGURE 2. Fracture of the penis in a 24-year-old man. After sexual activity, the patient had a loss of penile rigidity, pain, and hematuria. A Transverse, and (B) sagittal grayscale images of the penis demonstrate a defect in the right tunica albuginea (asterisk) with accompanying hematoma (arrowhead). C, Retrograde urethrogram reveals associated rupture of the penile urethra (arrow). The patient subsequently underwent surgical exploration and repair.

 

[madman]

FIGURE 3. A 52-year-old man presents with a painful erection after treatment with an injection of collagenase. A Transverse grayscale sonogram of the penis shows a heterogeneous collection (arrowhead) along the dorsal surface of the penis which represents a postprocedural hematoma. B, Transverse gray-scale sonogram of the base of the penis which shows a large homogenous hypoechoic collection along the dorsal surface of the penis (arrowhead). The tunica albuginea of the lateral left surface of the cavernosum is intact(arrow). Findings were consistent with a postprocedural hematoma.

 

[madman]

FIGURE 4. A 26-year-old man presents with penile pain during intercourse without loss of rigidity. A Transverse grayscale image of the penis demonstrates a heterogeneous hypoechoic collection within the corpus spongiosum representing a penile hematoma (asterisk). The tunica albuginea is seen to be intact.

 

[madman]

FIGURE 5. Cavernosal hematoma in a 44-year-old man presenting with pain after intercourse. A, Sagittal and (B) transverse grayscaleimages demonstrating a heterogeneous collection along the right cavernosum representing a hematoma (asterisk). The adjacent tunicaalbuginea is intact (arrow).

 

[madman]

FIGURE 6. A 52-year-old man presents with a red, inflamed, and painful penis. A Transverse grayscale image demonstrates a large collection (asterisk) within the corpora cavernosa with multiple echogenic foci (arrows) representing air. B, Sagittal grayscale image showing the same fluid collection, compatible with penile abscess.

 

[madman]

FIGURE 7. Penile prosthesis explant in a 72-year-old man. Axial contrast-enhanced CT of the pelvis at the level of the base of the penis demonstrates extensive air (arrow) within the penile parenchyma, mimicking penile abscess.

 

[madman]

Cocaine-induced priapism!


FIGURE 8. A 40-year-old man with cocaine-induced priapism. A Transverse grayscale of the penis demonstrates engorged corpora cavernosal with no flow in the cavernosal arteries (arrow). The longitudinal view shows absences of flow in the cavernosal after confirming hypoxic changes.

 

[madman]

FIGURE 9. A 27-year-old man with painless persistent erection after a recent penile injury from bull riding. The longitudinal color flow sonogram of the penis shows an area of color flow aliasing (arrow) within the left corpus cavernosum near the tip of the penis. B, Spectral waveform demonstrates a high-velocity, low-resistance blood flow pattern confirming the presence of a fistula. Images used with permission from the Journal of Ultrasound in Medicine.

 

[madman]

FIGURE 10. A 72-year-old man presents with Mondor disease of the penis. Sagittal color Doppler image hypoechoic clot and absent color flow in the deep dorsal vein (arrow) of the penis.

 

[madman]

FIGURE 11. Line drawing demonstrating the expected cavernosal artery spectral Doppler waveforms before and after prostaglandin injection. A, Flaccid, before injection (monophasic waveform). B, Filling, 5 minutes after injection, increase in peak systolic velocity and end-diastolic velocity. C, Tumescence, 10 minutes after injection(decrease in end-diastolic velocity). D, Full erection 15 minutes after injection (with reversal of flow in diastole). E, Rigidity, 20 minutes after injection (decrease in peak systolic velocity).

 

[madman]

FIGURE 12. A 57-year-old man presents with erectile dysfunction. A–F, Sagittal spectral Doppler images from 5 to 30 minutes after prostaglandin injection show a maximum velocity within the cavernosal artery of 24 cm/s at 20 minutes, which is consistent with arterial inflow disease. In addition, an increased end-diastolic velocity greater than 5 cm/s is present, indicating accompanying venous leak.

 

[madman]

FIGURE 13. A 63-year-old man with erectile dysfunction. Sagittal spectral Doppler images from 25 (A) and 30 (B) minutes after prostaglandin injection showing an end-diastolic velocity within the corpus cavernosal artery of 7.6 and 11.5 cm/s, respectively, consistent with venous leakage.

 

[madman]

FIGURE 14. A 58-year-old man with Peyronie disease. Patient presents with a compliant of erectile dysfunction and an irregular curvature of the penis. A, Transverse grayscale sonogram demonstrating a calcified plaque (arrow) along the tunica albuginea. B, Sagittal gray scale sonogram of the same patient.

 

[madman]

TABLE 1. Criterion Standard for Diagnosing Low-Flow PriapismIs Arterial Blood Gases

 

[madman]

TABLE 2. Diagnostic Criteria of Erectile Dysfunction Caused by Venous Leakage and Arterial Inflow Disease

 

[madman]

*Erectile dysfunction is a common condition, defined as the inability to attain or maintain penile erections of sufficient quality to allow satisfactory sexual activity. Approximately half of the men between ages 40 and 70 years experience erectile dysfunction, with physical or organic, psychologic, and pharmacologic etiologies.18 The most common cause of erectile dysfunction is a vascular disease resulting in endothelial dysfunction; comorbidity with cardiovascular disease, diabetes mellitus, hyperlipidemia, and hypertension is frequent.19 Duplex ultrasound can evaluate for vascular causes of erectile dysfunction and distinguish between arterial inflow and venous leakage.