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Scrotal Imaging

The scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy is a sac hanging outside the body that contains parts of the male reproductive system. The scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy’s main function is to support testicles Testicles The testicles, also known as the testes or the male gonads, are a pair of egg-shaped glands suspended within the scrotum. The testicles have multiple layers: an outer tunica vaginalis, an intermediate tunica albuginea, and an innermost tunica vasculosa. The testicles are composed of testicular lobules and seminiferous tubules. Testicles: Anatomy outside the body so that spermatogenesis Spermatogenesis The process of germ cell development in the male from the primordial germ cells, through spermatogonia; spermatocytes; spermatids; to the mature haploid spermatozoa. Gametogenesis can be completed under optimal conditions. The scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy can be affected by various pathologic conditions, and imaging is a valuable tool in reaching the appropriate diagnosis. The most important imaging method is ultrasonography +/– Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) mode because scrotal structures are superficial with no intervening gas. MRI is useful when ultrasound is indeterminate.

Last updated: Sep 3, 2021

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Ultrasonography

Overview

Ultrasonography is often the best imaging method for the scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy.

  • Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) mode: 
    • Useful for assessing vasculature for altered blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure 
    • Minimizes radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma to preserve gametes
    • Particularly useful in diagnosis of testicular torsion Testicular torsion Testicular torsion is the sudden rotation of the testicle, specifically the spermatic cord, around its axis in the inguinal canal or below. The acute rotation results in compromised blood flow to and from the testicle, which puts the testicle at risk for necrosis. Testicular Torsion
  • Indications for scrotal ultrasonography: 
    • Mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast 
    • Hydrocele Hydrocele Accumulation of serous fluid between the layers of membrane (tunica vaginalis) covering the testis in the scrotum. Varicocele, Hydrocele, and Spermatocele
    • Testicular torsion Testicular torsion Testicular torsion is the sudden rotation of the testicle, specifically the spermatic cord, around its axis in the inguinal canal or below. The acute rotation results in compromised blood flow to and from the testicle, which puts the testicle at risk for necrosis. Testicular Torsion
    • Infertility Infertility Infertility is the inability to conceive in the context of regular intercourse. The most common causes of infertility in women are related to ovulatory dysfunction or tubal obstruction, whereas, in men, abnormal sperm is a common cause. Infertility
    • Scrotal or inguinal hernia Inguinal hernia An abdominal hernia with an external bulge in the groin region. It can be classified by the location of herniation. Indirect inguinal hernias occur through the internal inguinal ring. Direct inguinal hernias occur through defects in the abdominal wall (transversalis fascia) in hesselbach’s triangle. The former type is commonly seen in children and young adults; the latter in adults. Inguinal Canal: Anatomy and Hernias
    • Orchitis Orchitis Inflammation of a testis. It has many features of epididymitis, such as swollen scrotum; pain; pyuria; and fever. It is usually related to infections in the urinary tract, which likely spread to the epididymis and then the testis through either the vas deferens or the lymphatics of the spermatic cord. Epididymitis and Orchitis
    • Epididymitis Epididymitis Epididymitis and orchitis are characterized by acute inflammation of the epididymis and the testicle, respectively, due to viral or bacterial infections. Patients typically present with gradually worsening testicular pain and scrotal swelling along with systemic symptoms such as fever, depending on severity. Epididymitis and Orchitis
    • Varicocele Varicocele A condition characterized by the dilated tortuous veins of the spermatic cord with a marked left-sided predominance. Adverse effect on male fertility occurs when varicocele leads to an increased scrotal (and testicular) temperature and reduced testicular volume. Varicocele, Hydrocele, and Spermatocele

Normal scrotal ultrasonography

  • Homogeneous Homogeneous Imaging of the Spleen echotexture
  • Epididymis Epididymis The convoluted cordlike structure attached to the posterior of the testis. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of spermatozoa. Testicles: Anatomy can be seen with the head at the superior pole of the testicle, extending to the tail at the inferior pole.
  • Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) mode:
    • Color images show arterial and venous flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure to testicle.
    • Spectral images demonstrate: 
      • Arterial waveform: demonstrates peaks and downslopes
      • Venous waveform: nearly equal heights

Epididymitis Epididymitis Epididymitis and orchitis are characterized by acute inflammation of the epididymis and the testicle, respectively, due to viral or bacterial infections. Patients typically present with gradually worsening testicular pain and scrotal swelling along with systemic symptoms such as fever, depending on severity. Epididymitis and Orchitis and orchitis Orchitis Inflammation of a testis. It has many features of epididymitis, such as swollen scrotum; pain; pyuria; and fever. It is usually related to infections in the urinary tract, which likely spread to the epididymis and then the testis through either the vas deferens or the lymphatics of the spermatic cord. Epididymitis and Orchitis

Ultrasound findings include:

  • Enlarged epididymis Epididymis The convoluted cordlike structure attached to the posterior of the testis. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of spermatozoa. Testicles: Anatomy
  • Increased blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure to the epididymis Epididymis The convoluted cordlike structure attached to the posterior of the testis. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of spermatozoa. Testicles: Anatomy: focal or diffuse
  • Decreased echogenicity of the epididymis Epididymis The convoluted cordlike structure attached to the posterior of the testis. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of spermatozoa. Testicles: Anatomy: focal or diffuse
  • Hydrocele Hydrocele Accumulation of serous fluid between the layers of membrane (tunica vaginalis) covering the testis in the scrotum. Varicocele, Hydrocele, and Spermatocele and scrotal wall thickening are common.

Hydrocele Hydrocele Accumulation of serous fluid between the layers of membrane (tunica vaginalis) covering the testis in the scrotum. Varicocele, Hydrocele, and Spermatocele

Ultrasound findings include:

Varicocele Varicocele A condition characterized by the dilated tortuous veins of the spermatic cord with a marked left-sided predominance. Adverse effect on male fertility occurs when varicocele leads to an increased scrotal (and testicular) temperature and reduced testicular volume. Varicocele, Hydrocele, and Spermatocele

Ultrasound findings include:

  • Veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology (e.g., pampiniform plexus) with a diameter > 2 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma
  • Best seen when comparing Valsalva images to resting images: reversal in blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure with this maneuver

Testicular torsion Testicular torsion Testicular torsion is the sudden rotation of the testicle, specifically the spermatic cord, around its axis in the inguinal canal or below. The acute rotation results in compromised blood flow to and from the testicle, which puts the testicle at risk for necrosis. Testicular Torsion

Ultrasound findings:

  • Normal ultrasound does not exclude torsion: consider repeat ultrasound within 4 hours if there is continued suspicion of torsion.
  • Enlarged hypoechoic Hypoechoic A structure that produces a low-amplitude echo (darker grays) Ultrasound (Sonography) testicle in comparison to the normal testicle
  • Spermatic cord Spermatic Cord Either of a pair of tubular structures formed by ductus deferens; arteries; veins; lymphatic vessels; and nerves. The spermatic cord extends from the deep inguinal ring through the inguinal canal to the testis in the scrotum. Testicles: Anatomy twisting 
  • No color or spectral flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure on Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) evaluation: loss of venous → arterial flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure
  • A testicle that is diffusely hypoechoic Hypoechoic A structure that produces a low-amplitude echo (darker grays) Ultrasound (Sonography) and small is a sign of infarction.

Testicular carcinoma

Ultrasound findings include:

  • Abnormal echogenicity
  • Mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast with increased blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure

MRI

Normal scrotal MRI

Table: Normal scrotal MRI
Structure T1-weighted T2-weighted With contrast
Testicle ( homogeneous Homogeneous Imaging of the Spleen oval structure) Hypointense Hypointense Magnetic Resonance Imaging (MRI) to isointense Hyperintense Hyperintense Magnetic Resonance Imaging (MRI) Enhance
Epididymis Epididymis The convoluted cordlike structure attached to the posterior of the testis. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of spermatozoa. Testicles: Anatomy Isointense Hypointense Hypointense Magnetic Resonance Imaging (MRI) Enhance
Tunica albuginea Tunica albuginea Penis: Anatomy Hypointense Hypointense Magnetic Resonance Imaging (MRI) Hypointense Hypointense Magnetic Resonance Imaging (MRI) Not applicable

Testicular cancer Testicular cancer Testicular cancer is the most common solid malignancy affecting men 15-35 years of age. Most of the testicular cancers are of the germ cell tumor type, and they can be classified as seminomas and nonseminomas. The most common presentation of testicular cancer is a painless testicular mass. Testicular Cancer

MRI findings include:

  • Heterogeneous testicular mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast
  • Irregular borders
  • Contrast enhancement
Transverse t1-weighted image depicts a multilobular left scrotal mass

Transverse T1-weighted image depicts a multilobular left scrotal mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast (short arrow), located in the paratesticular space.
The lesion had similar signal intensity when compared with the normal testicular parenchyma (asterisk).
Left hydrocele Hydrocele Accumulation of serous fluid between the layers of membrane (tunica vaginalis) covering the testis in the scrotum. Varicocele, Hydrocele, and Spermatocele (long arrow)

Image: “Transverse T1-weighted image” by Tsili AC, Argyropoulou MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction, Giannakis D, Sofikitis N, Tsampoulas K. License: CC BY 2.0

Clinical Relevance

  • Testicular torsion Testicular torsion Testicular torsion is the sudden rotation of the testicle, specifically the spermatic cord, around its axis in the inguinal canal or below. The acute rotation results in compromised blood flow to and from the testicle, which puts the testicle at risk for necrosis. Testicular Torsion: medical emergency in which the spermatic cord Spermatic Cord Either of a pair of tubular structures formed by ductus deferens; arteries; veins; lymphatic vessels; and nerves. The spermatic cord extends from the deep inguinal ring through the inguinal canal to the testis in the scrotum. Testicles: Anatomy, along with the spermatic artery inside it, twists, cutting off the blood supply. If left untreated, torsion results in testicular infarction, necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage, and subsequent infertility Infertility Infertility is the inability to conceive in the context of regular intercourse. The most common causes of infertility in women are related to ovulatory dysfunction or tubal obstruction, whereas, in men, abnormal sperm is a common cause. Infertility. Presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor is with sudden severe unilateral scrotal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, swelling Swelling Inflammation, nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics, and vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia. On physical examination, the testis is usually very tender to touch and swollen, with no pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways relief on scrotal elevation. The cremasteric reflex Cremasteric Reflex Male Genitourinary Examination is absent. Color Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) may show decreased blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure to the testicle, and this is usually enough to perform surgery in which detorsion is done.
  • Epididymitis Epididymitis Epididymitis and orchitis are characterized by acute inflammation of the epididymis and the testicle, respectively, due to viral or bacterial infections. Patients typically present with gradually worsening testicular pain and scrotal swelling along with systemic symptoms such as fever, depending on severity. Epididymitis and Orchitis and orchitis Orchitis Inflammation of a testis. It has many features of epididymitis, such as swollen scrotum; pain; pyuria; and fever. It is usually related to infections in the urinary tract, which likely spread to the epididymis and then the testis through either the vas deferens or the lymphatics of the spermatic cord. Epididymitis and Orchitis: 2 conditions that are characterized by the acute inflammation Acute Inflammation Inflammation of the epididymis Epididymis The convoluted cordlike structure attached to the posterior of the testis. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of spermatozoa. Testicles: Anatomy or the testis caused by viral or bacterial infection. Viral orchitis Orchitis Inflammation of a testis. It has many features of epididymitis, such as swollen scrotum; pain; pyuria; and fever. It is usually related to infections in the urinary tract, which likely spread to the epididymis and then the testis through either the vas deferens or the lymphatics of the spermatic cord. Epididymitis and Orchitis is more common in prepubertal boys and young adolescents, whereas bacterial infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease are more commonly seen in older adolescents. Individuals usually present with acute scrotal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, swelling Swelling Inflammation, dysuria Dysuria Painful urination. It is often associated with infections of the lower urinary tract. Urinary tract infections (UTIs), urinary frequency, and urgency. Ultrasound can show scrotal wall thickening, and Doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) ultrasound will demonstrate increased blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure. Antibiotic treatment of orchitis Orchitis Inflammation of a testis. It has many features of epididymitis, such as swollen scrotum; pain; pyuria; and fever. It is usually related to infections in the urinary tract, which likely spread to the epididymis and then the testis through either the vas deferens or the lymphatics of the spermatic cord. Epididymitis and Orchitis and epididymitis Epididymitis Epididymitis and orchitis are characterized by acute inflammation of the epididymis and the testicle, respectively, due to viral or bacterial infections. Patients typically present with gradually worsening testicular pain and scrotal swelling along with systemic symptoms such as fever, depending on severity. Epididymitis and Orchitis is indicated when the cause is suspected to be bacterial in origin.
  • Varicocele Varicocele A condition characterized by the dilated tortuous veins of the spermatic cord with a marked left-sided predominance. Adverse effect on male fertility occurs when varicocele leads to an increased scrotal (and testicular) temperature and reduced testicular volume. Varicocele, Hydrocele, and Spermatocele: dilatation of the pampiniform venous plexus that is connected to the internal spermatic vein. Varicoceles are associated with impaired testicular hormonal function and infertility Infertility Infertility is the inability to conceive in the context of regular intercourse. The most common causes of infertility in women are related to ovulatory dysfunction or tubal obstruction, whereas, in men, abnormal sperm is a common cause. Infertility. Most men with varicoceles present with infertility Infertility Infertility is the inability to conceive in the context of regular intercourse. The most common causes of infertility in women are related to ovulatory dysfunction or tubal obstruction, whereas, in men, abnormal sperm is a common cause. Infertility issues, but some may have scrotal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and heaviness. Ultrasonography of the scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy usually shows a tubular lesion that increases in size when the individual performs the Valsalva maneuver Valsalva maneuver Forced expiratory effort against a closed glottis. Rectal Prolapse. When varicoceles are symptomatic or associated with infertility Infertility Infertility is the inability to conceive in the context of regular intercourse. The most common causes of infertility in women are related to ovulatory dysfunction or tubal obstruction, whereas, in men, abnormal sperm is a common cause. Infertility and abnormal seminal fluid analysis, the treatment is surgical correction.

References

  1. Wittenberg, A.F., Tobias, T., Rzeszotarski, M., Minotti, A.J. (2006). Sonography of the acute scrotum: the four T’s of testicular imaging. Curr Probl Diagn Radiol 35:12–21. https://pubmed.ncbi.nlm.nih.gov/16399236/
  2. Andipa, E., Liberopoulos, K., Asvestis, C. (2004). Magnetic resonance imaging and ultrasound evaluation of penile and testicular masses. World J Urol 22:382–391. https://pubmed.ncbi.nlm.nih.gov/15300391/
  3. Watanabe, Y. (2002). Scrotal imaging. Curr Opin Urol 12:149–152. https://pubmed.ncbi.nlm.nih.gov/11859263/

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