Varicocele Imaging 

Updated: May 31, 2019
  • Author: Ali Nawaz Khan, MBBS, FRCS, FRCP, FRCR; Chief Editor: Eugene C Lin, MD  more...
  • Print

Practice Essentials

Varicoceles develop as a result of dilatation and tortuosity of veins of the pampiniform plexus secondary to retrograde flow into the internal spermatic vein (ISV). A varicocele is a common abnormality, occurring in approximately 15% of men. Some patients may have scrotal pain and swelling, but more importantly, a varicocele is considered to be a potential cause of male infertility. [1, 2, 3]  The prevalence of varicocele increases with advancing age (approximately 10% per decade of life), probably because of the aging of venous valves. [4, 5, 6]

The relationship between a varicocele and male infertility is controversial, but improved fertility and sperm quality have been reported after treatment, including occlusive treatment for varicoceles. On physical examination, large varicoceles are easily identified as the classic "bag of worms" surrounding the testis. Ultrasonography, particularly Doppler ultrasonography, allows accurate diagnosis of varicoceles, even subclinical varicoceles. Ultrasonography is the examination of choice for investigating varicoceles, and it remains the most practical and most accurate noninvasive technique. Ultrasonography does not always show reflux into the spermatic veins or pampiniform plexus. In addition, an ultrasonographic diagnosis of varicocele does not always indicate that such a lesion is the cause of the patient's symptoms and/or infertility. [1, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]

The existence of veins larger than 2 mm is a commonly used ultrasound criterion for diagnosing varicocele, with a sensitivity of 95%. [4, 18]

Functional MRI techniques, such as diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) MRI, and MR spectroscopy have been shown to provide important diagnostic information for diagnosing testicular diseases. [19, 20, 21]  The ionizing radiation of computed tomography (CT) scanning limits its use. Measurement of fractional anisotropy by 1.5 T diffusion tensor imaging (DTI) MRI was found, in a study by Tsili et al, to be useful for diagnosis of testes in infertile men with varicocele. FA was significantly lower in testes with varicocele compared to age-matched controls (P< 0.001). An optimal cut-off of FA 0.08 was found for the diagnosis of varicocele (sensitivity 88%, specificity 93.5%, positive predictive value  91.6%, and negative predictive value  90.6%). [22, 4, 19]

Venography is the most reliable modality for the detection of subclinical varicoceles, because the findings demonstrate abnormal retrograde flow into the spermatic veins or pampiniform plexus. However, the procedure remains invasive, as well as exposing the patient to ionizing radiation, and is usually reserved for patients undergoing sclerotherapy.

(See the images below.)

Longitudinal sonogram through the left testicle. T Longitudinal sonogram through the left testicle. This image shows several large anechoic tubes (2.4-6 mm in diameter) lying behind the upper and middle poles of the testicle. The diameter of these tubes increased by 1.5-2 mm with a Valsalva maneuver (not shown). T = testicle; v = varicocele.

Upper image: Longitudinal sonogram through the pa Upper image: Longitudinal sonogram through the pampiniform plexus of the left testis. The image shows several anechoic tubes. Lower image: The application of color Doppler imaging in the same patient shows bidirectional flow within the anechoic tubes.
Left testicular venogram. This image shows a left Left testicular venogram. This image shows a left testicular varicocele before embolization. Note: radiographs of varicoceles should be avoided to restrict radiation exposure.

The Dubin and Amelar classification is commonly used for varicocele clinical diagnosis, as follows [23] :

  • Grade 1. Varicocele detectable by palpation only during the Valsalva maneuver.
  • Grade 2. Varicocele detectable by simple palpation.
  • Grade 3. Varicocele visible on inspection and palpation.

Although the diagnosis and management of varicoceles have not been standardized, there are many published guidelines available, such as those by the American Society of Reproductive Medicine, American Urological Association, European Association of Urology, and World Health Organization. [24, 25, 26, 27, 28, 29, 30]

Next:

Computed Tomography

CT scanning with increased intra-abdominal pressure can be used as a noninvasive method to detect a varicocele and to show proximal extension of the lesion into the inguinal canal. However, exposure to radiation is a disadvantage. The sample of patients in whom the use of CT scanning has been reported is small. [31]

In one study, 2 transverse scans were obtained with the patient in a supine position during quiet breathing and during Valsalva maneuver. [32] The transsectional area of the spermatic cord was 80-100 mm2 on the side without the varicocele and 100-200 mm2 on the affected side. Increased intra-abdominal pressure dilated the veins of the pampiniform plexus, increasing the transsectional area by 40-80% on the side without varicocele and by 100-200% on the side with the varicocele. [32] The authors noted that a spermatic cord area (measured at the root of the scrotum) of greater than 100 mm2 without an increased intra-abdominal pressure and an area greater than 200 mm2 with an increased intra-abdominal pressure is indicative of a varicocele.

 

Previous
Next:

Magnetic Resonance Imaging

On MRIs, a varicocele is demonstrated as a mass of dilated serpiginous vessels, usually adjacent to the epididymal head. The spermatic canal is widened, and the intrascrotal spermatic cord and/or pampiniform plexus are prominent. Abdominal compression over the sacral promontory may exaggerate the serpiginous vessels. [22, 33, 4, 19, 20, 21]

The spermatic cord has a heterogeneous signal intensity. It contains serpiginous high signal intensity structures, which are presumably due to phase-shift artifact from slow blood flow.

Flow-related enhancement secondary to slow flow may result in an increased intraluminal signal intensity on images obtained with all MRI sequences.

Three-dimensional (3-D) phase-contrast magnetic resonance angiography (MRA) has been described in a series of 4 patients with recurrent varicoceles. The scrotal part of the varicocele was demonstrated in 3 patients, and the spermatic vein was shown in 2 patients. Some have suggested that this technique can provide an alternative to spermatic venography in the radiologic mapping of dilatated spermatic veins. [34]

In a study by Emad-Eldin et al, diffusion-weighted MRI sequence has been shown to be useful in evaluating the sequel of varicocele, with decreased apparent diffusion coefficient  (ADC) values being significantly correlated with abnormal semen parameters. [33]

Previous
Next:

Ultrasonography

Ultrasonographic findings of varicoceles include tortuous anechoic tubular structures adjacent to the testis. With the patient in an upright position, the diameter of the dominant vein at the inguinal canal measures more than 2.5 mm and is associated with an increase in diameter of at least 1 mm during a Valsalva maneuver. Varicoceles can be found anywhere in the scrotum (ie, medial, lateral, anterior, posterior, or inferior to the testis). They can be small to very large, with some enlarged vessels as large as 8 mm in diameter. Intratesticular varicoceles may appear as a vague hypoechoic area in the testis. They appear tubular or oval shaped and usually lie near the mediastinum testis. [4, 14]

Ultrasonography has been reported to have a 97% sensitivity and 94% specificity for the diagnosis of clinical varicocele. [22, 35, 14, 18, 15, 16]

Color Doppler ultrasonographic imaging can be helpful in differentiating venous channels from epidermoid cysts or spermatoceles when doubt exists. Bidirectional Doppler ultrasonography performed with the patient in the upright position with quiet respiration shows a shunt type of flow in 86% of patients in whom insufficient distal valves allow spontaneous and continuous reflux from the ISV into the cremasteric vein and the vein of the vas deferens. Bidirectional Doppler ultrasonography performed with the patient in the upright position with quiet respiration shows a stop type of flow in 14% of patients in whom intact valves allow only sporadic reflux from the spermatic vein into the pampiniform plexus with a Valsalva maneuver. [36]  Doppler ultrasonography can be used to grade venous reflux as static (grade I), intermittent (grade II), or continuous (grade III). [37, 15, 16, 17]

Using the diameter as the criteria of venous channel dilatation, Hamm et al found that ultrasonography had a sensitivity of 92.2%, a specificity of 100%, and an accuracy of 92.7%. [38]  Ultrasonography is capable of demonstrating both palpable and subclinical varicoceles.

Epidermoid cysts and spermatoceles may mimic varicoceles. If in doubt, color Doppler ultrasonographic findings are diagnostic. Intratesticular varicoceles may mimic tubular ectasia.

Effective sclerotherapy is indicated when venous dilatation resolves and the overall diameter of the veins decreases.

Tissue elastography ultrasound measures the stiffness of tissue. According to Dede et al, acoustic radiation force impulse (ARFI) elastography can measure early damage of testicular structure by varicoceles. In the study, mean elastography was significantly lower in testes with varicoceles [17, 39, 40, 41]

(Ultrasonographic characteristics of varicoceles are demonstrated in the images below.)

Longitudinal sonogram through the left testicle. T Longitudinal sonogram through the left testicle. This image shows several large anechoic tubes (2.4-6 mm in diameter) lying behind the upper and middle poles of the testicle. The diameter of these tubes increased by 1.5-2 mm with a Valsalva maneuver (not shown). T = testicle; v = varicocele.
Transverse ultrasonography scan through the left t Transverse ultrasonography scan through the left testicle. This image shows several cystic structures (2.4-4 mm in diameter) behind the testis. Color flow Doppler image demonstrates flow within these cystic structures (not shown).

Upper image: Longitudinal sonogram through the pa Upper image: Longitudinal sonogram through the pampiniform plexus of the left testis. The image shows several anechoic tubes. Lower image: The application of color Doppler imaging in the same patient shows bidirectional flow within the anechoic tubes.
Line diagram of a typical bidirectional Doppler re Line diagram of a typical bidirectional Doppler recording of a stop-type varicocele (red) in which flow is stopped by a competent valve in the pampiniform plexus above the level of communicating veins. The shunt-type of varicocele is depicted in blue. Because the valves in the pampiniform plexus contiguous to the testicular veins are incompetent or absent, venous flow is shunted via communicating veins into orthograde draining veins; these are shown to represent deferential and cremasteric veins at contrast venography. On bidirectional Doppler sonograms, steady flow is recorded in both retrograde and orthograde fashions. Note: Several factors affect the flow, including the position of the patient, Valsalva maneuvers, and the position of the probe.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Sonogram depicting a combination of an intratestic Sonogram depicting a combination of an intratesticular and extratesticular right-sided varicocele.
Patient with bilateral microcalcification and vari Patient with bilateral microcalcification and varicocele, also some intratesticular varicocele. Courtesy of Shlomo Gobi, Sonographer.
Varicocele and color-flow mapping. Courtesy of Shl Varicocele and color-flow mapping. Courtesy of Shlomo Gobi, Sonographer.
Varicocele with reflux during Valsalva maneuver on Varicocele with reflux during Valsalva maneuver on spectral Doppler. Courtesy of Shlomo Gobi, Sonographer.
Varicocele with reflux during Valsalva maneuver on Varicocele with reflux during Valsalva maneuver on spectral Doppler. Courtesy of Shlomo Gobi, Sonographer.

 

Previous
Next:

Nuclear Imaging

Technetium-99m (99mTc)–labeled red blood cells are the radiopharmaceutical agent of choice for the evaluation of varicoceles, although other radionuclides have been used as well. Images are obtained with the patient in both the supine and erect positions. Static images reveal moderate to intense intrascrotal accumulation of the labeled red cells; this accumulation may be discrete or patchy. Palpable and nonpalpable varicoceles have been identified on blood-pool images, but cases of reflux without increased blood pool usually cannot be identified on static images. [42]

A Valsalva maneuver during image acquisition may be helpful in detecting subclinical cases. The importance of detecting subclinical cases is related to the proposed association of varicoceles to infertility.

The use of dynamic scanning is controversial. A reduction in early blood flow on the affected side has been observed. Dynamic images allow calculation of the difference in arrival time of radioactivity between the iliac artery and the pampiniform plexus; this time is believed to shorten with increasing grades of varicoceles.

As with most scrotal pathologies, bilateral disease is difficult to confirm on scrotal radionuclide imaging. The sensitivity for clinically apparent varicoceles has been reported to be 90%. The specificity is difficult to determine.

Previous
Next:

Angiography

Venography is the most reliable modality for the detection of small or subclinical varicoceles, because findings demonstrate abnormal venous blood reflux in a retrograde fashion into the internal spermatic vein (ISVs) and the pampiniform plexus. Because of the invasive nature of venography, the technique is usually reserved for use in patients undergoing occlusive therapy for mapping of the venous anatomy. Occasionally, it is used in symptomatic patients when the diagnosis is equivocal with other methods. Testicular veins often spasm, and rarely, opacification of the vein with contrast medium may be difficult. Moreover, problems may be encountered in cannulating the right testicular vein.

(See the images below.)

Left testicular venogram. This image shows a left Left testicular venogram. This image shows a left testicular varicocele before embolization. Note: radiographs of varicoceles should be avoided to restrict radiation exposure.
Digital subtraction angiogram. This image shows se Digital subtraction angiogram. This image shows several coils (arrows) overlying the left of the fifth lumbar vertebral body after embolization of the left testicular vein.

 

Previous