testicular and scrotal ultrasound
Acute scrotal
ultrasound: a practical guide. Normal scrotal US. Longitudinal US image of the right testis in an asymptomatic 23-year-old shows a normal-appearing testis. The central echogenic band (arrow) represents the mediastinum testis. Note a small, physiologic amount of peri-testicular fluid (arrowhead)
Acute scrotal
ultrasound: a practical guide. Scrotal trauma. a Testicular rupture. Longitudinal US of the right testis in a 19-year-old male following jet ski accident. There is disruption of the tunica albuginea (arrowheads) and extrusion of a large amount of the inferior pole of the testis (annotated by letter E); the normal tunica albuginea is noted more superiorly (arrow). Also note surrounding hematocele (asterisk). The patient underwent debridement and repair with preservation of the superior aspect of the right testis. b Testicular fracture. Longitudinal US of the left testis in a 47-year-old who sustained a traumatic scrotal injury after being struck by a baseball traveling at high velocity. The thin hypoechoic band (arrows) corresponds to the testicular fracture line. Orchiectomy was performed due to extent of injury. c Penetrating testicular trauma with intrascrotal gas. Transverse US of the left testis in a 25-year-old who sustained a traumatic scrotal injury after a hand gun discharged while in the patient’s pants pocket. A focal defect (arrow) along the lateral aspect of the left testis corresponds to a site of tunica albuginea rupture and tubule extrusion. A cluster of amorphous echogenic foci with mild posterior shadowing in the testicular parenchyma are due to intratesticular gas. The patient was treated with orchiectomy
Acute scrotal
ultrasound: a practical guide. Epididymo-orchitis and complications. a Epididymo-orchitis. Longitudinal color Doppler US in a 31-year-old with acute left scrotal pain and recent diagnosis of Chlamydia trachomatis. There is extensive hyperemia of the epididymal head (arrowhead) and testis (arrow) compared to the contralateral side (not shown). The patient’s symptoms resolved after treatment with doxycycline. b Scrotal abscess. Transverse US image of the left testis in a 59-year-old paraplegic patient with recurrent epididymo-orchitis and scrotal abscesses. The left testis is nearly replaced by a heterogeneous fluid collection (small arrows). In the medial aspect, there is a cluster of echogenic foci (arrowheads) which result in reverberation artifact/‘dirty shadowing’ (large arrow) due to a gas component. Cultures following surgical drainage grew Pseudomonas aeruginosa and Enterobacter cloacae. c Vasitis. Longitudinal US image of the left inguinal canal in a 46-year-old with left scrotal and pelvic pain. There is hyperemia of the epididymal head and spermatic cord (arrow) as it traverses the inguinal canal. Note the normal-appearing superior aspect of the testis (arrowheads). d Vasitis. Axial CT image of the pelvis (same patient as in part c) shows an enlarged and inflamed left vas deferens (arrows). The right vas deferens is normal (arrowheads). The patient’s symptoms resolved after treatment with Ciprofloxacin
Acute scrotal
ultrasound: a practical guide. Massive scrotal edema. Longitudinal US in a 55-year-old with cirrhosis and anasarca shows extensive thickening of the scrotal wall (asterisk). The testis is normal-appearing (arrowhead). The scrotal wall is noted (arrow). The patient was treated conservatively and edema eventually resolved
Acute scrotal
ultrasound: a practical guide. Inguinal hernia resulting in acute scrotal pain. a Longitudinal US image of the right inguinal canal in a 39-year-old with right scrotal pain shows an elongated heterogeneous structure in the right inguinal canal (arrowheads); hyperechoic regions corresponded to fat while hypoechoic, serpiginous structures corresponded to vessels. The right testis (arrow) was normal. b Corresponding coronal T2 weighted MR image shows bilateral inguinal hernias containing fat (arrows) and vessels (arrowheads), but no bowel. Note normal-appearing testes (asterisks). The patient underwent herniorrhaphy
Acute scrotal
ultrasound: a practical guide. Perineal abscess presenting as scrotal pain. a Transverse color Doppler US image in a 33-year-old patient with scrotal pain and history of suppurativa hidradenitis shows an encapsulated heterogeneous fluid collection (arrowheads) in the perineum. b Corresponding CT image (same patient as in part a) shows the low attenuation fluid collection posterior to the base of the penis. The patient was treated with incision and drainage. Cultures were consistent with a polymicrobial infection, mostly due to Staphylococcus aureus
Acute scrotal
ultrasound: a practical guide. Testicular infarction due to torsion. Longitudinal US image in an 18-year-old presenting with pain approximately 30 h after onset of symptoms. Despite use of power Doppler and technique optimization, there is no flow in the testis. The testis is hypoechoic centrally (arrowhead) consistent with infarction. Orchiectomy yielded an infracted testis
Acute scrotal
ultrasound: a practical guide. Acute scrotal pain due to segmental testicular infarction following aortic graft placement. a Longitudinal US image of the testis with shows a geographic region of decreased echogenicity at the superior aspect of the right testis. There was no color Doppler flow shown in this segment. b Corresponding (same patient as in part a) post-contrast T1 weighted image with fat saturation shows lack of enhancement at in a geographic region at the superior pole of the right testis. The findings were presumably due to an embolic event in the peri-procedural period. The patient was treated conservatively and symptoms resolved
Testicular and scrotal ultrasound is the primary modality for imaging most of the male reproductive system. It is relatively quick, relatively inexpensive, can be correlated quickly with the patient's signs and symptoms, and, most importantly, does not employ ionizing radiation.
MRI is occasionally used for problem solving if the diagnosis is unclear on ultrasound. CT is only rarely needed, and is avoided because of its ionizing radiation. Nuclear medicine studies (e.g. Tcm-pertechnetate) have also fallen out of favor because of their ionizing radiation.
Normal ultrasound anatomy
Testis
- homogeneous echogenicity
- a prepubertal testis has a slightly decreased echogenicity relative to an adult
- mildly coarse echotexture
- adult diameter measures between 3-5 cm, with a volume of ~20 mL
- the tunica (vaginalis/albuginea) appears as an echogenic outline of the testicle:
- the tunica invaginates to form the linear echogenic testicular mediastinum (a.k.a. mediastinum testis)
- the rete testis can be identified in ~20% of patients
- hypoechoic region near the mediastinum
- more noticeable if dilated
- appendix testis: attached to upper pole of testicle, near the epididymis
- not usually seen unless torsion is present
- spectral Doppler: the testis demonstrates a low-resistance arterial waveform
Epididymis
- epididymal head: round or oblong structure located near the superior pole of the testicle
- isoechoic or mildly hyperechoic relative to the testicle
- measures 5-12 mm
- epididymal body: extends down the posterior aspect of the testicle
- measures 2-4 mm
- epididymal tail: curved structure at the inferior pole of the testicle and becomes the proximal ductus deferens
- measures 2-5 mm
- appendix epididymis: attached at the epididymal head
- not normally seen unless torsion present
- spectral Doppler: epididymis demonstrates a low-resistance arterial waveform
Scrotum
- normal scrotal skin thickness varies between 2-8 mm
Technique
A high-frequency transducer (9-15 MHz) is usually used for evaluation of the testes and scrotum, except in certain circumstances (e.g. massive hydrocele), when a lower MHz transducer is used.
- patient is supine
- patient may be upright when looking for an inguinal hernia
- scrotum is supported on a towel laid over the thighs
- testicles should be evaluated in both long and short axes
- if a scrotal mass is found, one of the primary roles of ultrasound is to determine if it is intratesticular or extratesticular
- intratesticular mass: generally malignant
- extratesticular mass: 3-6% malignant
- if a scrotal mass is found, one of the primary roles of ultrasound is to determine if it is intratesticular or extratesticular
- color and spectral Doppler parameters should be set for low flow
- low wall filter and low pulse repetition frequency
- power Doppler may be necessary to prove testicular torsion
- important: both a short axis grayscale and a color Doppler image should be obtained, in which both testicles are imaged side-by-side ("buddy shot" or "sunglasses view"), to compare the size, relative echogenicity and blood flow
- scrotum should be examined for extratesticular masses or processes
Tips:
- use enough gel to eliminate gas trapped in the skin folds of the scrotum
- do not change the setting when moving from one testicle to the other
See also
Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Sonographie des Skrotums und Hodens:
