scrotal doppler

scrotal doppler

1. SCROTAL DOPPLER Dr. Pradeep Patil Professor Dept of Radiodiagnosis DY Patil Medical college and Hospital Kolphapur

2. Arterial supply of testis T esticular artery arises from -- aorta E xtends directly to the testicle and epididymis, following the course of the spermatic cord and the body of the epididymis. Structures other than the testicle and epididymis receive arterial supply from cremasteric artery – origin from inferior epigastric deferential branches – origin from internal iliac arteries Although the testicular arteries provide the principal arterial supply to the testicle and epididymis, anastomotic channels exist among all of the scrotal arteries, permitting collateral flow.

3. The testicular (or spermatic) artery follows the course of the epididymal body through the mediastinum testis Then gives off capsular branches that circle the periphery of the testicle, beneath the tunica albuginea. The capsular arteries give off centripetal arteries that course through the testicle toward the mediastinum and then loop back for a short distance as the recurrent rami. The venous drainage parallels the arterial distribution.

4. The venous drainage of each testicle and epididymis is via a network of tiny veins called the pampiniform plexus. This network gradually coalesces to form two or three veins that follow the spermatic cord and unite as the spermatic (testicular) vein. On the left, the spermatic vein drains into the ipsilateral renal vein O n the right , the spermatic vein drains into the inferior vena cava.

5. Normal colour and spectral doppler of testis Spectral Doppler Arterial flow to the testicle and epididymis -exhibits a low-resistance pattern with continuous flow during diastole In contrast, a high-resistance blood flow pattern is seen in extragonadal arteries example-cremasteric system. These arteries are occasionally visualized along the course of the spermatic cord. It is important not to mistake extragonadal Doppler flow signals for testicular flow C olor Doppler P ostpubertal boys and adults, blood are seen within and at the periphery of the testicle.

6. Peak systolic velocity in testicular arteries ranges from 4 to 19 cm/s (mean 9.7 cm/s). E nd-diastolic velocity ranges from 1.6 to 6.9 cm/s (mean 3.6 cm/s). Prerequisite for quantitative assesment Sufficiently long arterial segment shoul d be visualized with color doppler imaging allowing for angle correction of the doppler signal. When angle correction is not possible, spectral doppler features are evaluated qualitatively. Uses of quantitative assesment Assessment of arterial pulsatility patterns Measurement of blood flow velocities and velocity ratios Comparison of testicular blood flow from one side to the other quantitatively.

7. Sonographic technique TRANSDUCER A linear-array transducer with a frequency of10 MHz or higher is used. A lower frequency setting may be needed if the scrotum is severely swollen. COLOUR DOPPLER SETTINGS Color velocity scale must be set to a low setting to detect very low velocity blood flow signals. A relatively high color Doppler gain setting is needed. Use an appropriate spectral display scale to maximize the size of the doppler waveform display. One method to improve the visualization of blood flow signals is to increase the color Doppler gain until artifacts appear in the image and then decrease the gain slightly

8. In some normal individuals, one or more large artery/vein pair(s) may traverse the testicle obliquely from the mediastinum. These transmediastinal vessels may be visible on gray-scale imaging and should not be mistaken for pathology.

9. Epididymitis and orchitis Infection is the most common cause of acute scrotal pain and tenderness Most common cause - infection caused by sexually transmitted organisms (principally Neisseria gonorrhoeae and Chlamydia trachomatis) They ascend through the genital tract tail of the epididymis infection spreads throughout the epididymis (epididymitis). testicle ( epididymo -orchitis) scrotal cavity, generating an infected hydrocele

10. Ultrasound features Enlargement of involved structures. Decreased echogenicity of the affected structures. Increased blood flow (hyperemia) on color or power doppler examination. A hydrocele (excess scrotal fluid) is often present Scrotal wall may become edematous and/ or inflamed.

11. In some cases findings are less obvious and are based solely on side-to-side comparison of epididymal size, echogenicity, and blood flow patterns. Obviously, side-by-side comparison is not helpful in cases of symmetrical, bilateral infection; nevertheless, hyperemia of the scrotal contents may still be evident in such cases. .

12. Focal orchitis- It is noteworthy that focal orchitis may be seen as a focal, hypoechoic area of inflammation at the periphery of the testicle, adjacent to an infected epididymal head This should not be mistaken for a testicular tumor but should be followed to resolution after antibiotic treatment.

13. The epididymis and testicle usually return to a normal sonographic appearance following an episode of infection Complications of epidydimoorchitis - Chronic epididymitis ( untreated or incompletely treated cases ). Abscesses. Severe cases, testicular atrophy or infarction may occur. Atrophy is a noteworthy complication of mumps orchitis.

14. Chronic epidydimitis Diffuse thickening and heterogeneity of the epididymis Or focal, heterogeneous epididymal mass. Increased blood flow may not be a feature of chronic epididymitis. Hydrocele may also be present, and this may be septated or contain echogenic material.

15. Epidydimal abscess These appear as complex fluid collections with irregular walls,sometimes containing diffuse or dependent debris. Increased blood flow caused by hyperemia may be apparent in the surrounding tissues, either focally or diffusely. If an epididymal abscess becomes chronic, hyperemia may no longer be evident.

16. Varicocele Common cause of a palpable scrotal mass and pelvic discomfort. In some individuals, a varicocele contributes to low sperm count, decreased sperm motility, and infertility. These problems have been attributed to persistent hyperemia-induced elevation of testicular temperature

17. The veins of the pampiniform plexus, which drain the testicle and epididymis, are normally quite small, but these may dilate and become tortuous forming a tangle of enlarged veins along the course of the spermatic cord and epididymis Causes- Valvular incompetence Elevated venous pressure

18. Why are varicoceles MC on left? Varicoceles are more common on the left side of the scrotum than the right because of elevated pressure in the left spermatic vein. Cause- The left spermatic (testicular) vein inserts into the left renal vein, which drapes across the aorta and may be compressed between the aorta and superior mesenteric artery, raising venous pressure. Higher hydrostatic pressure than the right because of its longer course. Spermatic vein obstruction as a result of an intra-abdominal mass should be considered whenever an isolated right scrotal varicocele is diagnosed.

19. Diagnosis Color doppler ultrasound when numerous veins of unusually large size(>3mm) are seen along the spermatic cord or epididymis. The extent of the varicosities should be documented, and the largest veins should be measured. The presence of reflux within the veins can be investigated by having the patient perform the valsalva maneuver during color doppler imaging.( The demonstration of reflux in the veins during a Valsalva maneuver is further evidence of potential clinical significance of a varicocele )

20. Grading of varicocele grade I : reflux at the level of groin only during the Valsalva maneuver , grade II : reflux at the level of the proximal segment of the pampiniform plexus only during the Valsalva maneuver grade III : reflux in the distal vessels at the level of lower scrotum only during the Valsalva maneuver grade IV : spontaneous reverse flow, increasing during the Valsalva maneuver , with scrotal deformation and possible testicular hypotrophy. grade V : resting reflux in the dilated pampiniform plexus, possibly increasing during the Valsalva maneuver , always accompanied by testicular hypotrophy.

21. Testicular torsion Definition- Torsion refers to twisting of the testicle within the scrotal sac, such that the arteries and veins are compressed and blood flow is compromised. Torsion usually occurs in children or young adults, and two peaks of incidence have been noted: the neonatal period and puberty. Torsion in neonates is typically extravaginal . Torsion during puberty and in young adults is virtually always intravaginal

22. Intravaginal torsion- Where the parietal tunica vaginalis remains intact, while the scrotal contents inside the parietal tunica twist. Extravaginal torsion- That is, the entire contents of the scrotum twist on the spermatic cord, including the parietal and visceral layers of the tunica vaginalis.

23. Bare area of testicle- Normally, the parietal layer of the tunica vaginalis lines the inner wall of the scrotal sac until it reaches the edge of the testicle, where it reflects over the testicle, forming the visceral layer of the tunica vaginalis The portion of the testicle that is not covered by the visceral layer of the tunica vaginalis is closely held against the scrotal wall and called the bare area. Vessels and tubules from the spermatic cord enter and leave the testicle across the bare area.. When the bare area is abnormally small (bell clapper deformity), the attachment of the testicle to the scrotal wall is narrow and the testicle is at risk of torsion because of twisting at this attachment.

24. Pathological sequence Spermatic cord twists, with a rotation of at least 360 degrees, at the bare area. Venous obstruction- swelling and increased pressure(inside testis and spermatic cord) Arterial flow becomes occluded Testicular ischemia results Progressing to infarction If detorsion does not occur surgically or spontaneously.

25. ACUTE TORSION- (first 6 to 10hrs) During which the testicle suffers ischemia without permanent injury if detorsion occurs. MISSED TORSION-(after 24hrs) The stage after which testicular infarction has occurred to the point that the testicle cannot be saved even if detorsed

26. B- mode and color doppler ultrasound is the imaging method of choice for diagnosing testicular torsion. Soon after torsion occurs- Testicle may appear normal in echotexture Spermatic cord and epididymis may appear as a thick echogenic structure with acoustic shadowing caused by twisting and the knot. On doppler imaging blood flow will appear diminished or absent in the testicle and the knotted cord and epididymis. If blood flow is still present on the affected side, spectral waveforms typically demonstrate high-resistance flow( resistive index  (RI >0.75))  , compared with the low resistance flow in the normal testicle

27. As the torsion persists- Testicle becomes enlarged and hypoechoic due to swelling and edema A small hydrocele may be seen. With color doppler imaging, Blood flow remains diminished or absent in the testicle and epididymis.

28. If there is further progression- Testicular necrosis occurs. Testicle becomes mottled and heterogeneous with hypoechoic areas. Scrotal wall becomes thickened and hypervascular . If detorsion of the testicle occurs- In such cases, the affected testicle may be hyperemic compared with the normal testicle In these cases, the knot of the twisted cord and epididymis will not be present. If the testicle is examined during the hyperemic period, increased blood flow may be mistaken for orchitis.

29. Neonatal or extravaginal torsion- Swelling of the testicle with generalized decreased echogenicity and absence of blood flow in the affected testicle The swollen testicle and epididymis maintain their anatomic relationship because both the parietal and visceral layers of the tunica vaginalis have torsed with the testicle . Sometimes, fluid is seen in two spaces surrounding the testicle, an inner collection within the parietal tunica vaginalis and a rim of fluid outside the parietal tunica.

30. Scrotal masses Testicular cysts Epididymal cysts Testicular neoplasms

31. Testicular cysts Most intratesticular cyst are located near the mediastinum testicle. Cysts located on the testicular surface are almost always tunical cysts, arising in the tunica albuginea.

32. Sonographic features:- Anechoic contents. Sharply defined borders and an invisible wall. Enhanced through transmission of ultrasound. No blood flow within or surrounding the cyst (other than normal testicular vessels).

33. Epididymal cysts More common than testicular cysts. Most common location - epididymal head. They may be single, multiple, unilateral, or bilateral. Unlike testicular cysts, epididymal cysts may be septated or even multilocular and occasionally they may be several centimeters. Have same sonographic features as testicular cysts Epididymal cysts have no solid components, have exquisitely thin walls, and show no internal blood flow on color doppler examination.

34. Testicular neoplasms Ultrasound can distinguish intratesticular from extratesticular pathology with extremely high accuracy. Nevertheless, ultrasound generally cannot differentiate between different histologic types of testicular tumors, nor can it generally differentiate between malignant (common) and benign (uncommon) neoplasms.

35. B- mode ultrasound features- Most testicular tumors - are well-defined hypoechoic intratesticular masses Some may be poorly marginated or grossly infiltrating. They may exhibit some degree of internal heterogeneity because of hemorrhage and/or necrosis, and calcifications are occasionally present.

36. Colour doppler- Internal vascularity is evident within testicular neoplasms on the color doppler flow examination. Large avascular areas may be present in a testicular tumor when necrosis or hemorrhage is present. Most malignant tumors are hypervascular .

37. Spectral doppler – Shows low-resistance blood flow within tumor vessels, a typical finding seen in malignant neoplasms . Blood flow velocities may be substantially elevated in markedly hypervascular tumors.

38. Mimics of neoplasms Inflamed areas (without frank abscess formation)- focal orchitis Infarcts Abscesses Contusions Hematomas Color and spectral doppler features are of considerable importance in differentiating these etiologies. No flow is present in abscesses, infarcts, and hematomas,but hypervascularity may be present in the periphery of these lesions.

39. Focal testicular infarction Causes Trauma(testicular contusion or testicular fracture compromising blood flow) Infection Vascular compromise(vasculitis or other causes of vascular compromise) Infarction following an infection(compromised blood flow - secondary to edema compressing venous flow) The affected area is usually at the periphery of the testicle near the epididymal head or tail, common sites of focal orchitis.

40. On ultrasound and doppler examinations, The infarct may appear as a discrete, wedge-shaped or round testicular lesion that is heterogeneous and hypoechoic. Little or no blood flow on color doppler imaging The surrounding parenchyma may appear normal. The infarct may contain cystic areas if necrosis has occurred. In some cases, a testicular infarct may be indistinguishable from a testicular tumor and the diagnosis is only made at pathology after orchiectomy If an infarct is suspected on the basis of the patient’s history, age, and sonographic appearance, close sonographic and Doppler follow-up is indicated, to be certain the lesion decreases in size with time, proving that it is not a tumor.