Section for residents

Section for residents ULTRASOUND IN ACUTE SCROTAL PATHOLOGY Luciana C. Della Rosa, Sabrina Trezzo, David Ortiz, Martín Broguet, Norberto O. Sánchez, Roberto L. Villavicencio. Abstract Acute scrotal pathology is a clinical emergency that requires rapid diagnosis to install an early treatment. The most frequent causes of acute scrotal pathology are traumatic, infectious and vascular. Because all these conditions have similar symptoms characterized by pain and swelling, the ultrasound is a safe and accessible method that provides a great advantage for the accurate diagnosis and subsequent therapeutic management. Resumen La patología escrotal aguda constituye una situación clínica de urgencia que requiere un rápido diagnóstico para instalar un tratamiento precoz. Las causas más frecuentes de patología escrotal aguda son traumáticas, infecciosas y vasculares. Debido a que todas estas patologías tienen una sintomatología similar, caracterizada por el dolor y la tumefacción, el uso de la ecografía como método de imagen, inocuo y accesible, proporciona una gran ventaja para el diagnóstico preciso y posterior manejo terapéutico. key words: scrotal, acute, ultrasound Palabras claves: escroto, agudo, ecografía Introduction Ultrasound is a technique highly sensitive and specific not only for diagnosis but for the characterization of the different acute scrotal pathologies (ASP). During the last decades, it has become an essential tool to study patients with these pathologies, as it provides an accurate diagnosis in most cases, determining the decision for the appropriate treatment. Therefore, the objective of this iconographic essay is to present ultrasound findings associated with the different acute scrotal alterations and demonstrate the usefulness of the Doppler study as a complementary technique in the determination of the testicular stage and perfusion and of the differential diagnosis (1-5). Acute Pathology Acute scrotal alterations can be classified as traumatic, infectious and vascular (Table 1) (1-5). Traumatic Causes Scrotal trauma is present in less than 1% of a trauma injuries and it is determined mainly by anatomic (localization) and physiological (scrotal mobility) factors. Scrotal traumatic lesions often present a maximum incidence in patients of between 10 and 30 years of age. There are two types of trauma: direct kick to the groin and penetrating injuries. The main cause of testicular trauma is associated with sports. Ultrasound is indicated for the search of a lesion needing early surgery. A delay or an inadequate diagnosis can result in consequences and complications such as reduced fertility, infections, ische- Contact information: Luciana C. Della Rosa. Sanatorio Parque. Oroño 860. Grupo Oroño - Fundación Villavicencio. Rosario (2000) - Santa Fe - Argentina. e-mail: lucianadellarosa@gmail.com Recibido: 8 de Agosto de 2012 / Aceptado: 10 de Febrero de 2013 Received: August 8, 2012 / Accepted: February 10, 2013 Vol. 2 / Nº5 - Agosto, 2013. 49

mia, infarction and testicular atrophy (1). Testicular lesions associated with trauma are varied and they include hematoma, hydrocele, hematocele, testicular fracture or rupture. Sometimes, these pathologies can appear simultaneously. Hematomas may have an intra-testicular localization (Fig. 1 and 2) or they can be located in the extratesticular soft tissue (scrotal wall or epididymis). Lesions are generally focal and single or rarely multiple, appearing hyperechogenic (acute hematomas) or heterogeneous hypoechogenic (chronic hematomas) in ultrasound, according to their chronological stage (1, 2). Doppler study is essential for the assessment of the vascular suffering resulting from pedicle compression due to the hematoma. The hematoma in the scrotal wall manifests itself as a focal thickening or as liquid formations seen in the haemal sinus of the wall. Hematocele is a complex set which divide the visceral and parietal layers of the tunica vaginalis. They are similar to hematomas since they appear hyperechogenic but become hypoechogenic with time (Fig. 3). The diagnosis of testicular fracture is considered when there is a visualization of a hypoechogenic belt dividing the testicle in two or more parts. Generally, with this pathology, the testicular edges are smooth and the tunica albuginea is intact. In the testicular rupture, there can be an external protrusion of the testis parenchyma or of the hemorrhage inside the scrotal sac; therefore, the identification of a segmentary interruption of the echogenic line corresponding to the albuginea is decisive for this diagnosis. The testicular rupture is considered a surgical emergency. The ultrasound shows poorly defined testicular edges, heterogeneous testicular echo-structure of the parenchyma with focal hyper- and hypo-echogenic areas corresponding to hemorrhages, and vascular alterations (1, 2). Some authors have reported a sensitivity of 100% and a specificity of 93.5% for the diagnosis of rupture, in the presence of a testicle with a heterogeneous parenchyma, poorly defined edges and associated disrupted albuginea (3). Tab. 1: 50 Revista Argentina de Diagnóstico por Imágenes

Fig. 1: Subcapsular Hematoma. Right testicle, longitudinal view: Alterations of the testicular echo-structure with peripheral hyperechogenicity and central hypoechogenicity are seen, compatible with intratesticular subcapsular evolved after a certain time (arrows). Fig. 2: Testicular Trauma. Marked alteration of the testicular parenchyma with areas of different blood flow echogenicity, some slightly perfused and others with an absence of irrigation (closed trauma). Fig. 3: Hematocele. Presence of blood in the scrotal sac because of trauma. The hyperechogenicity of the hematic content represents the acute characteristic. Vascular Causes Testicular torsion of the spermatic cord may limit the flow to and from the testicle. It commonly affects children and adolescents. The most frequent subtype is the intravaginal torsion, associated with a predisposing anatomic factor, the "bell-clapper" testicle (4). This is due to an anomaly in the development of the vaginal process, and therefore, the testis is inadequately affixed to the inguinal canal, allowing it to move in an abnormal way. The testicle and the spermatic cord are allowed to rotate 360 or more with the consequential decrease of artery contribution and venous return responsible for an ischemic necrosis. In these cases, the importance and promptness of initial symptoms depend on the number of rotations and the degree of arterial compression. The extravaginal testicular torsion is more frequent in perinatal stages (4). This type of torsion is produced at the level of the internal inguinal ring, affecting the entire scrotal content. Whatever type of early diagnosis is essential since it determines the testicular viability rate (100% during the first 6 hours, 70% during the first 6 to 12 hours and 20% during the first 12 to 24 hours). Therefore, ultrasound and Doppler evaluation are essential (5). After 24 hours, testicular impairment is irreversible, so it becomes a true emergency and the ultrasound study may delay, in no case, surgical treatment. Clinical features and examinations are characteristic. Generally, the torsion is spontaneous although there may be a history of trauma, exposition to cold weather, exercising or sexual stimuli. Before it becomes an acute pathology, it is frequent to experience slight or moderate testicular pain due to minor rotation that did not come to produce a complete torsion. Clinically, it is characterized by acute pain and increasing tension of the affected testicle with redness and scrotal edema, which can be accompanied with a neurovegetative disorder (sweating, nausea, vomiting). There is no micturition syndrome and fever is rare, appearing only in evolved cases where there is an associated testicular necrosis. The physical exam shows a hard and very sensitive testicle retracted to the inguinal canal. The ultrasound aspect varies with time: During the first hours (2-4 hours), the B-mode ultrasonography Vol. 2 / Nº5 - Agosto, 2013. 51

shows a normal testicle. After 4-6 hours, the testicle has increased volume with diffuse or focal hypoechogenicity due to the edema (Fig. 4). Several hours later, the parenchyma is heterogeneous due to irreversible lesions. Testicular atrophy evolves later. Generally, it is associated with a minor hydro-hematocele. Doppler mode is more sensitive than B-mode, showing perfusion anomalies prematurely. Color Doppler clearly shows the absence of intratesticular vascularization compared to the contralateral testicle (Fig. 5 and 6). After 24 hours of complete torsion, a hypervascular ring around avascular testicle due to the development of peri-testicular collateral circulation (3-6). On the other hand, the testicular appendix is a remnant of the mesonephric and paramesonephric Müllerian duct. They are sessile structures with certain predisposition to torsion allowing for the definition of an acute scrotal syndrome. The Hydatid of Morgagni has a higher frequency of torsion (90% of cases). Clinically, it can simulate a testicular torsion, although the pain is localized specifically in the upper portion of the testis. Ultrasound evidences a small hypo- and hyperechogenic paratesticular or epididymal mass, frequently surrounded by a reactive hydrocele. In color-flow Doppler ultrasound the hypo- and hyperechogenic formation indicating infarcted appendix does not show internal flow while the testicle shows normal flow since its vascular structures are not compromised by the process (Fig. 7) (4). The treatment for the hydatid torsion is medical with analgesics and in some cases antibiotic prescription. Fig. 4: Testicular Torsion. Ultrasound study, longitudinal view: increased size of the left testicle, showing a dotted aspect due to ischemia. The tunica albuginea is intact and a slight reactive hydrocele is observed. Fig. 5: Testicular Torsion. Comparative ultrasound of both testicles: evidence of increased size of the left testicle, with poorly defined hypoechoic intraparenchymatous areas. The left testicle shows absence of blood flow in color Doppler mode. Fig. 6: Testicular Torsion and Doppler. Image acquired on an axial view with Power Doppler mode, showing absence of testicular blood flow. Fig. 7: Hydatid Torsion. Ultrasound exam shows normal epididymis (EPIDIZQ). Next to it, an appendix of increased size is observed, with absence of blood flow (HIDAT). Note the hydrocele with a reaction to torsion (HI- DROC). 52 Revista Argentina de Diagnóstico por Imágenes

Infectious Causes Acute bacterial infection is the most frequent scrotal pathology in young and adult men. It mainly affects the epididymis, later spreading to the testicle in approximately 25%-40% of the cases (5). It is caused by sexually transmitted diseases or retrograde propagation of bacterial infections, generally resulting from the urinary system. In most cases, primitive orchitis has a viral origin and it is generally associated with parotitis. Affection in these cases is bilateral, as opposed to bacterial orchiepididymitis, where inflammation is often unilateral. Independently from the pathogen involved, ultrasound often shows a focal or global increase in size of the epididymis, with a decrease of its echogenicity. These findings are generally related to the thickening of scrotal coverings (more than 5 mm) and reactive hydrocele. The affected testicle shows increased echogenicity, alternating with hypoechogenic areas (Fig. 8-11). Doppler mode is more sensitive than B-mode, clearly showing the hypervascularization of the compromised testicle epididymis, which should be evaluated in relation to the contralateral testicle. The sensitivity of the Doppler mode is close to 100%. Even though ultrasound is routinely performed when there are clinical symptoms of orchiepididymitis (to confirm the diagnosis), the real interest of the ultrasound should be limited to the atypical forms when there are severe symptoms, resistance to appropriate antibiotic therapy or when there is a suspicion of associated complications such as abscess (epididymal or testicular), which is generally presented as a hypoechogenic liquid area of slightly irregular edges with hypo-isoechogenic halo, often with sediments (Fig. 12). Ultrasound and Doppler mode play a decisive role in the differentiation between testicular infectious process and torsion (in its subacute form) (3-5). Finally, funiculitis is the inflammatory affection of the spermatic cord and it is generally associated with epididymitis. When an ultrasound study is performed, the spermatic cord is seen with an increase in size, with ectatic and serpiginous vessels of the pampiniform plexus (Fig. 13). Fig. 8: Acute Orchitis. Ultrasound study of both testicles, axial view: prominent increase in irrigation of the left testicle, especially in the caudal region. The right testicle has normal vascular flow. Fig. 9: Focal Orchitis. The study shows an intraparenchymatous hypoechoic area in the upper portion of the right testicle, corresponding to focal acute orchitis. The patient evolved favorably with antibiotic therapy. Vol. 2 / Nº5 - Agosto, 2013. 53

Fig. 10: Acute Epididymitis. Ultrasound image, axial view of the epididymis tail: increased in volume and heterogeneous signal because of parenchymatous inflammatory changes. Fig. 11: Acute Epididymitis and Doppler. Longitudinal image: increase in diameter of the left epididymis at the level of the head, which is heterogeneous with an increase of flow in Doppler mode. Fig. 12: Testicular Abscess. Ultrasound image: heterogeneous mass (ABSC), with an increase of the perilesional flow, corresponding to an intratesticular abscess. Fig. 13: Funiculitis. The study shows a clear increase in the thickness of the right spermatic cord, which is hyperechogenic (arrows) and has increased flow in color Doppler at spectral analysis. Summary The testicular ultrasound constitutes a useful technique for the diagnosis, characterization and differentiation of acute scrotal pathologies (traumatic, infectious and vascular). Color Doppler and colorflow Doppler are essential tools in the study of patients who are suspected to suffer from an acute scrotal vascular pathology and in the differentiation of such pathology from scrotal infectious alterations. Bibliography 1- Deurdulian C, Mittelstaedt CA, Chong WK, Fielding JR. US of acute scrotal trauma: optimal technique, imaging findings and management. Radiographics 2007; 27:357-369. 2- Bhatt S, Dogra VS. Role of US in Testicular and Scrotal Trauma. Radiographics 2008; 28:1617-1629. 3- Buckley JC, McAninch JW. Use of ultrasonography for the diagnosis of testicular injuries in blunt scrotal trauma. J Urol 2006; 175:175 178 4- Aso C, Enríquez G, Fité M, et al. Gray-Scale and Color Doppler Sonography of Scrotal Disorders in Children: An Update. Radiographics 2005; 25:1197-1214. 5- Roy C, Tuchman C. Echographie Scrotale: pathologies non tumorales courantes. J Radiol 2003; 84:581-595. 6- Cassar S, Bhatt S, Paltiel HJ, Dogra VS. Role of Spectral Doppler Sonography in the Evaluation of Partial Testicular Torsion. J Ultrasound Med 2008; 27:1629-1638. 54 Revista Argentina de Diagnóstico por Imágenes