Penile sonography: technique, utilities and radiological findings

Transcription

1 Penile sonography: technique, utilities and radiological findings Poster No.: C-0494 Congress: ECR 2013 Type: Educational Exhibit Authors: U. Sobrino Castro, A. Fuentes Morán, V. Martinez Valderrabano, M. Tijerín Bueno, C. Antolín Pérez, S. Molnar Fuentes ; Leon/ES, Leonn/ES Keywords: Genital / Reproductive system male, Ultrasound, UltrasoundColour Doppler DOI: /ecr2013/C-0494 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 49

2 Learning objectives -The sonography is the gold standard for the initial penile study, and it is as useful as unknown for the general radiologist. Trough this presentation I would like to have a review on: The basic technique to perform the sonography. The main utilities and its characteristics. The sonographic findings. Background ANATOMICAL REVIEW The penis is part of the male reproductive system. It has a ventral and a dorsal surface. It consists of three erectile columns: two corpora cavernosa and the corpus spongiosum. The corpora cavernosa are placed in the dorsal side and are the only ones trully involved in the erection. They are made out of vascular sinusal venous spaces (erectile tissue) with the cavernosal artery irrigating the tissue. Those sinusal spaces are interconnected. They both (the corpora cavernosa) are surrounded by a connective tissue layer, called the tunica albunginea and they are freely connected through an incomplete medial septum. The corpus spongiosum is localted in the ventral side of the penis, in between both corpora cavernosa,and the main function is to support and protect the urethra. Both (the corpora cavernosa and the corpus spongiosum) are covered by a strong, deep, fibours tissue layer called the Buck`s fascia. See figure 2 Page 2 of 49

3 Fig. 2: Anatomy of the penis References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES The arterial supply comes from the superficial external pudendal arteries, that arises from the femoral artery, and it gives these branches (in order): Bulbar artery. Corpus spongiosum artery. Cavernosal arteries (their branches are named helical arteries). The dorsal penile artery (is located in between the albunginea and Buck s fascia) and it supplies the blood for the superficial layers of the penis. See figure 3. Page 3 of 49

4 Fig. 3: Arterial anatomy References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES The venous system has a double supply, with a superficial and a deep dorsal vein of the penis. The superficial dorsal vein is located outside Buck s fascia and underneath the skin, and is encharged for the superficial tissue.this system belongs to the external iliac vein. The deep dorsal vein of the penis runs between the albunginea and Buck s fascia and collects the blood from the sinusal spaces through the emissary veins to the circumflexes, and belongs to the internal iliac vein system. See figure 4. Page 4 of 49

5 Fig. 4: Venous anatomy References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES SONOGRAPHIC ANATOMY In the sonographic scan we have to main type of images, those seen in the transversal axis and those in the longitudinal one. In the transversal axis the corpus spongiosum is seen in the ventral side of the penis as a hyperechoic circular surface. The corpora cavernosa are placed dorsally, slightly hypoechoic, with the cavernosal artery in the middle of it (seen as a hyperechoic lineal structure, easier to see in colour doppler mode) and separate by a thin hyperechoic membrane, the tunica albunginea. See figure 5 Page 5 of 49

6 Fig. 5: Sonographic anatomy References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES In the longitudinal axis, the corpus spongiosum is identified superficially surrounded by a superficial hyperechoic membrane (Buck s fascia). Each corpus cavernosum is placed deeply from the corpus spongiosum and they are separate by the tunica albunginea. In this axis we can get to see the cavernosal artery all along its trail, and also its branches, the helical arteries. This is the optimal plane for the dynamic doppler sonography scan. See figure 6. Page 6 of 49

7 Fig. 6: Sonographic anatomy References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES SONOGRAPHIC TECHNIQUE: The ultrasonography is the first choice image study for the initial evaluation of the penile pathology, this is because this technique allows performing a functional and morphologic penile study. As we have seen in the previous lines, the sonographic study lets us visualize the anatomy of the erectile columns and the vascular anatomy; on top of that we can perform a dynamic doppler sonographic study in repose and activated status (after the use of vasodilators drugs). The main advantages compared to other techniques is its high availability, the fact that is easy to perform and train, versatility and that is is minimally invasive, and of course, it is low-cost. Page 7 of 49

8 The basic requirements for an standard and quality study are: The room should be conditioned: the privacy of the room is essential (making sure there is a lock and there will be no interruption), it has to be a quiet place, and we should have a low-light atmosphere. See figure 7. Fig. 7: The room References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES The patient should be place in supine position in the table. The penis has to be in dorsal flexion. We should scan the patient with the transducer laying on the ventral surface of the penis; this is important so that the study is reproducible after the erection for the dynamic doppler sonographic study. To scan the patient we need a high frequency transducer (7,5-10 MgHz). See figure 8. Page 8 of 49

9 Fig. 8: The transducer References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES First of all we do mode B sonographic study in the transversal axis from the base to the apex of the penis and afterwards in the longitudinal axis (this is the ideal plane to do the doppler sonographic study). It is important not do apply pressure on the transducer and we may need quite a lot of sonographic gel. Images for this section: Page 9 of 49

10 Fig. 2: Anatomy of the penis Page 10 of 49

11 Fig. 3: Arterial anatomy Page 11 of 49

12 Fig. 4: Venous anatomy Page 12 of 49

13 Fig. 5: Sonographic anatomy Page 13 of 49

14 Fig. 6: Sonographic anatomy Page 14 of 49

15 Fig. 7: The room Page 15 of 49

16 Fig. 8: The transducer Page 16 of 49

17 Imaging findings OR Procedure details UTILITIES: The ultrasonogrphy is the ideal technique for the diagnostic approach of the penile pathology. The main utilities of it can be divided in: 1. Erectile dysfunction 2. Painful penile induration 3. The penile Trauma 1. ERECTILE DYSFUNCTION To understand the physiopathology of the erection it is essential to go back and review the physiologic mechanism that makes erection possible. Relaxed status: the sinusal spaces are collapsed, and the emissary veins drain the content to the deep dorsal penile vein. In this status the arterial supply has a high resistance pattern due to epinefric tone. When there is some stimulus the parasympatic system gets activated (acetylcholine has an effect on the smooth muscle and endothelial cells). This produces the relaxation of the smooth muscle of cavernosal arterioles and sinusal spaces. Is in this moment when we have a low resistance flow pattern. The distention of the sinusal spaces produces the compression and partial occlusion of the emissary veins, and this causes a decrease in the venous drainage and penile engorgement, responsible of the erection that is maintained due to the parasympatic system. All this process is illustrated on figure 9. Page 17 of 49

18 Fig. 9: physiology of the erection References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES The erectile dysfunction is understood to be the inability to get or maintain the erection. There are many mechanism involved that can cause it, such as: Psychogenic cause Organic: Vascular: arterial or venous insufficiency Neurologic: parasympatic system affection Hormonal Trauma The dynamic doppler pulsed sonography study with local injection of vasodilator drugs (in the corpora cavernosa) help us diagnose those vascular disorders, and thus classifythe Page 18 of 49

19 patients in a nosological entity, which is mandatory for the management and prognosis of the patient. Dynamic doppler sonography with vasodilator drugs: Before starting the procedure the patient should sign an informed consent. The study needs to be performed in a quiet room, without interruptions. There are many vasodilator drugs available, the one we use and have at our institution, alprostadil 1% (E1 PG), that simulates the biochemical stimulus of the erection. The patient has to be placed supine on the exploring table, and we do a basal study in a relaxed status, where we should appreciate a high resistance pattern with a PSV (Peak Systolic Velocity) < 15 cm/ seg. With a compressor in the base of the penis we proceed to the injection of 5 ml of E1PG,ina corpus cavernosum (dorsal surface) with a fine needle. If it is injected in the corpus spongiosum or urethra that would have no effect, and be a false negative. 5 minutes later we will release the compressor. The pulsed doppler study of the cavernosal artery min after the injection (in the base of the penis in the longitudinal axis we have a 60 degree angle, optimal for the doppler study). Doppler study parameters The results of the cavernosal injection of vasodilators can be evaluated in three areas such as inspection, caliber change of the cavernosal artery and doppler parameters. Penile tumescence grades: I: no answer II: slight tumescence III: tumescence without stiffness IV: nearly complete answer V: complete erection Caliber change of the cavernosal artery: It is a normal answer if the caliber increases > 70%in the diameter of the vessel. Because the cavernosal artery is a vessel with a tiny caliber, so this is not very useful and no reproducible, so it leads to frquent pitfalls. Page 19 of 49

20 Pulsed doppler dynamic study: - To obtain an erection an increase of the PSV is needed, and the minimun PSV (peak systolic velocity) after the drug injection must be 25 cm/sec, which is meant to be enough supply to distend the sinusal spaces. -We also need to maintain that erection, through a decrease in the venous drainage, which is evaluated as an End Dyastolic Velocity (EDV) < 5 cm / seg, which would ensure enough blood accumulated in the sinusoids without early drainage. See figure 10 and 11 Fig. 10: Dynamic doppler sonography References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES Page 20 of 49

21 Fig. 11: Dynamic doppler sonography References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES A PSV < 25 cm /sec is diagnostic of arterial insufficiency. See figure 12. Page 21 of 49

22 Fig. 12: arterial insufficiency References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES An EDV > 5 cm/ sec represents una venous insufficiency. See figure 13. Page 22 of 49

23 Fig. 13: Venous insufficiency References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES If both parameter come together altered we call it combined or mixed insufficiency, as seen in figure 14. Page 23 of 49

24 Fig. 14: Combined insufficiency References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES The worst and most severe complication of this procedure is the low flow priapism, due to the absence of complete diastole, than can lead to a penile ischemia. If this last for longer than 3 hours a surgical venous drainage could be necessary. 2. PAINFUL PENILE INDURATION There are many causes for the penile painful induration, such as the presence of focal lesions, La Peyronie disease, inflammatory changes (in the context of diabetes, after PG self-injection), dorsal venous thrombosis, or corpus cavernosum thrombosis. The most frequent ones are la Peyronie disease and focal lesions. La Peyronie disease Page 24 of 49

25 It is the most frequent cause of painful penile induration. The cause of this disease is unknown, and it produces the formation of fibrous plaques in the tunica albunginea. The symptoms are pain, penile deformity, shortening and sexual impotence. The plaques change with the time and there are a few stages they would go across. Those different stages can be sonographically identified. -Soft plaques are isoechoic and they are identified as some slight alteration in the echoestructure (figure 15) with no deformity in the morphology. Those plaques are usually palpable, and thus recognizable. Fig. 15: Penile induration References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES -The fibrous plaques are hyperchoic and despite the alteration in the echoestructure there is albunginea s retraction associated. The penis adquires a concave morphology Page 25 of 49

26 due to this albunginea s retraction of the surface (figure 16). That s why the penile inspection prior to the scan is useful. Fig. 16: Penile induration References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES - The final stage of the plaques is the calcification. See figure 16. In the last two stages if the plaques affect the arteries (cavernosal, helical or arterioles) it can lead to erectile dysfunction, so when we are at these stages, so it would be necessary to perform a dynamic doppler sonography, as seen in figure 16. Focal lesions: This is the least frequent cause. It can be due to primary squamous tumors of the penis, that have a very low incidence (even less if circumcised). Page 26 of 49

27 A more frequent cause is the presence of hematogenous metastasis in the inside of the corpora cavernosa, and the main origin can be prostate and rectum cancer. See figure 17. Fig. 17: Penile induration- metastasis References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES In the case of unknown primary tumor, the sonography can also be a guide for interventional procedures, such as biopsy or fine-needle aspiration. 3.PENILE TRAUMA: The penile trauma can be due to a closed or penetrating trauma. Closed trauma is more common. The most frequent lesions are rupture of the erectile columns, vascular lesions and hematomas. Page 27 of 49

28 Hematomas Hematomas in the subcutaneous are unfrequent. They are due to indirect closed trauma with the penis in a relaxed status. It is prone to happen in patients with coagulation disease (figure 18). Fig. 18: Penile trauma References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES Hematomas can also occur in the inside of a corpus cavernosum in the case of a very focal trauma. See figure 19. The hematoma may have different echogenicity depending on the chronology and in the end stage it is an anechoic collection. A complication of this hematomas is a pseudoaneurism. Page 28 of 49

29 Fig. 19: Penile trauma References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES Postraumatic pseudoaneurism or sino-cavernosal fistula Postraumatic pseudoanerism are a very infrequent complication in the context of penile trauma. This happens in patients with a previous closed penile trauma that develop an intumescence 1 week to 1 month after the trauma. It is due to a lesion in the cavernosal artery that is leaking and communicated to the sinusal spaces. Afterwards the patient develops a high flow priapism (due to arterial supply into the sinusal spaces in the area of the lesion). In the doppler sonographic study a fluid collection is seen ( different echogenicity depending on the chronology of it) with high Peak Systolic Velocity, high resistance, aliasing, and mixed venous and arterial flow). Treatment: selective endovascular procedure to embolize the psedoaneurism. Page 29 of 49

30 Penile rupture This is a urologic emergency, due to a closed trauma in an erect penis, or a penetrating trauma. It is defined by the rupture of an erectile column (corpora cavernosa), produced by a tear in the albunginea, forming a hematoma. During erection, because the penis is engorged the albunginea gets thinner ( from 2mm to 0,5 mm), which makes it less distensible and so it has a higher risk for rupture. The most important prognostic factor is the integrity of the albunginea and the exact point of the tear. It usually only affects to one corpus cavernosum (if the spongiosum is affected we d later have to check the urethral integrity) in the distal 2/3 of it and affecting less than 50% of the circumference (figure 20). Page 30 of 49

31 Fig. 20: Penile rupture References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES In the sonographic study the first thing we will notice is a large hematoma surrounding the corpora cavernosa and the corpus spongiosum, and later we have to look for the heterogenicity of the affected corpus cavernosum, where we must find the albunginea s interruption (see figures 20, 21 and 22). Page 31 of 49

32 Fig. 21: Penile rupture References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES Page 32 of 49

33 Fig. 22: Penile rupture References: radiodiagnóstico, Complejo Asistencial Universitario de León - Leon/ES Symptoms: audible crack, immediate pain, sudden erection lost, swallowing, ecchymosis and penile deviation to the opposite side of the rupture (this is a clue on where to look for the rupture, and once again inspection before sonography is important). The treatment is an emergent surgical procedure: hematoma evacuation and albungineal repair. Images for this section: Page 33 of 49

34 Fig. 9: physiology of the erection Page 34 of 49

35 Fig. 10: Dynamic doppler sonography Page 35 of 49

36 Fig. 11: Dynamic doppler sonography Page 36 of 49

37 Fig. 12: arterial insufficiency Page 37 of 49

38 Fig. 13: Venous insufficiency Page 38 of 49

39 Fig. 21: Penile rupture Page 39 of 49

40 Fig. 20: Penile rupture Page 40 of 49

41 Fig. 19: Penile trauma Page 41 of 49

42 Fig. 18: Penile trauma Page 42 of 49

43 Fig. 17: Penile induration- metastasis Page 43 of 49

44 Fig. 16: Penile induration Page 44 of 49

45 Fig. 15: Penile induration Page 45 of 49

46 Fig. 22: Penile rupture Page 46 of 49

47 Fig. 14: Combined insufficiency Page 47 of 49

48 Conclusion CONCLUSION: Penile sonography is the first choice image technique for the initial study of the penile pathology, and every radiologist should be familiar with it. This is a simple, cheap, ubicuous, and of great utility technique, because it allows performing a morphological and functional study. The morphological scan has to be done in mode B sonography, with a high frequency transducer in the longitudinal and transversal axis. The functional study is done through a dynamic doppler sonographic study after the local injection of vasodilator drugs. The main utilities are the erectile dysfunction, the painful penile induration and the penile trauma. References Painful Penile Induration: Imaging Findings and Management. Michele Bertolotto, Pietro Pavlica, Giovanni Serafini, Emilio Quaia, and Roberta Zappetti.Radiographics MarchApril : MR Imaging of the Penis E. Scott Pretorius, Evan S. Siegelman, Parvati Ramchandani,and Marc P. Banner.Radiographics October :S283-S298 MR Imaging of Acute Penile Fracture.Moon-Hae Choi, Bohyun Kim, Jeong-Ah Ryu, Sung Won Lee, and Kyu Sung Lee.Radiographics September : Color Doppler US of the Postoperative Penis: Anatomy and Surgical Complications Michele Bertolotto, Giovanni Serafini, Gianfranco Savoca, Giovanni Liguori, Loretta Calderan, Cristiana Gasparini, and Roberto Pozzi Mucel. Radiographics May-June : Page 48 of 49

49 Color Doppler Imaging of Posttraumatic Priapism before and after Selective Embolization. Michele Bertolotto, Emilio Quaia, Fabio Pozzi Mucelli, Sandro Ciampalini, Balázs Forgács, and Ignazio Gattuccio.Radiographics March : Color Doppler sonography in the evaluation of erectile dysfunction. S W Fitzgerald, S J Erickson, W D Foley, E O Lipchik, and T L Lawson. Radiographics January :3-17 Diagnóstico por ecografía. Rumack, Wilson, Charboneau. 2º edicion. Editorial marban. Disgnóstico por imagen. Tomo 3: genitourinario. Pedrosa. 1ª edición. Editorial marbán. Personal Information Uxía Sobrino Castro Attending radiologist in Hospital Dr Jose Molina Orosa, Lanzarote, SPAIN Contact uxiarx@gmail.com Page 49 of 49