Imaging and Procedure details:
In this article we reviewed urethral normal anatomy,
pathologies on different imaging modalities.
Cross-sectional imaging modalities,
including ultrasonography,
magnetic resonance (MR) imaging,
and computed tomography,
are useful for evaluating urethral pathalogies.
*Female normal urethral imaging features
Fluoroscopy
-Micturating cystourethrogram (MCU):
- This study will reveal a "spinning-top" appearance with normal 'wavy' walls caused by the pelvic floor muscles
Fig. 3: MCU female urethra shows spinning top configuration
References: (https://anatomy-library.com/img/bladder-neck-anatomy-mri-11.htm)l
-Retrograde urethrogram:
- Proves troublesome because the balloon will almost completely fill the urethra but special equipment can be used
Ultrasound
- Transvaginal,
transperineal or transurethral approach can all be used
- Imaged as as tubular structure anterior to the vagina,
coursing between the bladder and the vestibule of the vagina
Fig. 4: Ultrasound imaging by 3D US, coronal section of a normal intact IUS in a normal continent woman; notice two echoes, muscle overlying collagen, and the muscle is connected above with the detrusor muscle
References: (El Hemaly AK, Kandil IM, Kurjak A, Kamel LA, Serour AG. Ultrasonic Assessment of the Urethra and the Vagina in Normal Continent Womenand Women Suffering from Stress Urinary Incontinence and Vaginal Prolapse. Donald School Journal ofultrasound in Obstetrics and Gynecology. 2011 Apr 25;5(4):330-8.)
MRI
The use of an endovaginal coil has been shown to significantly improve SNR and image quality.
On T1C+ or T2 axial images the female urethra appears "target-like" with four layers
- Lower signal outer ring
- Higher intensity outer zone
- Low signal inner ring
- High signal inner zone
Fig. 5: Normal MR imaging anatomy of the female urethra: Axial T2-weighted image shows that the urethra has a characteristic target like appearance with four concentric rings: an outer ring of low signal intensity (O), a middle layer of higher signal intensity (M), an inner ring of low signal intensity (I), and a high signal-intensity zone in the center (C).
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Fig. 6: Normal MR imaging anatomy of the female urethra :Sagittal T2-weighted image shows similar zonal anatomy. C center zone, I - inner ring, M-middle layer, O -outer ring.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
*Male urethra normal imaging features
-Fluoroscopy
- The division into anterior and posterior urethras is important in terms of pathology and in imaging the urethra:
- The anterior urethra being visualized by performing a retrograde (ascending) urethrogram and
- The posterior urethra with an antegrade (descending or micturating) urethrogram.
Fig. 7: MCU male urethra
References: https://anatomy-library.com/img/anatomy-male-urethra-urethrogram-31.html
Ultrasound of male urethra
-Ascending urethra ultrasound technique
- Ultrasound was performed using a high-frequency linear array transducer with direct skin contact along the ventral surface of the penis.
Fig. 8: Normal urethral anatomy as seen on ultrasound normal bulbar urethra.
References: (Shaida N, Berman LH. Ultrasound of the male anterior urethra. The British journal of radiology. 2012 Nov;85(special_issue_1):S94-101)
-Descending urethral ultrasound technique
- The patient attends with a full bladder and voids into a receptacle.
Urethral distension is achieved with the urine stream,
which is interrupted by the patient gently clamping the penis between thumb and forefinger during voiding,
approximately 2 cm proximal to the tip after retraction of the foreskin.
Fig. 9: Normal navicular fossa seen during voiding descending urethral ultrasound
References: (Shaida N, Berman LH. Ultrasound of the male anterior urethra. The British journal of radiology. 2012 Nov;85(special_issue_1):S94-101)
Fig. 10: Normal urethra in transverse section. CC, corpus cavernosum; S, spongiosum surrounding urethra; U, urethral lumen.
References: (Shaida N, Berman LH. Ultrasound of the male anterior urethra. The British journal of radiology. 2012 Nov;85(special_issue_1):S94-101)
MRI
-T2
- Axial: membranous urethra is a low-intensity outer ring surrounding a high-intensity inner epithelium
- Sagittal and coronal images may show the course of the anterior and posterior urethra but often the proximal prostatic and penile urethra are not well seen unless there is an in-dwelling (foley) catheter
Fig. 11: Normal MR imaging anatomy of the male urethra Axial T2-weighted image obtained through the midprostate shows the prostatic urethra (P) in the posterior prostate as a small round structure of high signal intensity.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Fig. 12: Normal MR imaging anatomy of the male urethra Midline sagittal T2-weighted image shows the course of the urethra from the bladder neck to the proximal bulbous urethra (B). The anterior penile urethra is not well seen. M -membranous urethra, P - prostatic urethra.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
*IMAGING IN URETHRAL PATHOLOGIES
Congenital Anomalies
Congenital anomalies of the urethra include
-Anomalies of number
-Anomalies of form
- Posterior urethral valves
- Congenital stricture,
- Congenital polyp,
- Congenital diverticulum
-Malformations of the urethral groove
*Female Urethral pathologies
-Urethral duplication
-Congenital urethral polyp and diverticulum
- Occur most commonly in male patients and are rare in female patients.
-Ectopic ureteral orifice
- In about 15% of cases,
the ectopic ureter opens caudal to the normal orifice,
anywhere in the posterior wall of the urethra,
in a urethral diverticulum,
or in the urethrovaginal septum.
- In female patients,
the urethra and vestibule are the most common sites.
Fig. 13: MCU study of an adult female shows urinary bladder descent and herniation consistent with cystocele and bladder diverticulae (arrow a).
References: (Jain A, Setia V, Agnihotri S. Spectrum of Micturating Cystourethrogram Revisited: A Pictorial Assay. International Journal of Collaborative Research on Internal Medicine & Public Health. 2016 Nov 1;8(11):603)(Jain A, Setia V, Agnihotri S. Spectrum of Micturating Cystourethrogram Revisited: A Pictorial Assay. International Journal of Collaborative Research on Internal Medicine & Public Health. 2016 Nov 1;8(11):603)
Fig. 14: MCU study of a female child demonstrates ectopic insertion of left ureter into the proximal urethra (arrow a) with vesicoureteric reflux on left.
References: (Jain A, Setia V, Agnihotri S. Spectrum of Micturating Cystourethrogram Revisited: A Pictorial Assay. International Journal of Collaborative Research on Internal Medicine & Public Health. 2016 Nov 1;8(11):603)
Fig. 15: Ectopic ureter in a 35-year-old woman. Axial T2-weighted image shows a dilated right distal ureter (UR) located between the vagina (V) and urethra (arrowhead), a position that is lower than normal. Insertion of the right distal ureter into the urethra is not well demonstrated on this view
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Fig. 16: Three-dimensional ultrasound pictures of normal continent woman:the IUS(arrow) is torn mainly in the lower part showing a ‘flask-shape’ appearance
References: (El Hemaly AK, Kandil IM, Kurjak A, Kamel LA, Serour AG. Ultrasonic Assessment of the Urethra and the Vagina in Normal Continent Womenand Women Suffering from Stress Urinary Incontinence and Vaginal Prolapse. Donald School Journal ofultrasound in Obstetrics and Gynecology. 2011 Apr 25;5(4):330-8.)
Fig. 17: MCU study of a female child demonstrates corkscrew urethra (arrow a).
References: (Jain A, Setia V, Agnihotri S. Spectrum of Micturating Cystourethrogram Revisited: A Pictorial Assay. International Journal of Collaborative Research on Internal Medicine & Public Health. 2016 Nov 1;8(11):603).
*Male Urethra
-Epispadias
- It is a rare congenital anomaly that is almost always associated with exstrophy of the bladder.
- The roof of the urethra is absent,
and the urethra opens anywhere between the base and the glans of the penis.
-Hypospadias
- It is a congenital defect of the anterior urethra,
which opens anywhere along the ventral aspect of the penile shaft.
Fig. 18: Descending urethral ultrasound in hypospadias assessment demonstrating (a) a pinhole ventrally placed meatus and (b) a distal post-operative irregularity. The penile tip is to the left of the images.
References: (Shaida N, Berman LH. Ultrasound of the male anterior urethra. The British journal of radiology. 2012 Nov;85(special_issue_1):S94-101)
Fig. 19: Hypospadias in a male patient who demonstrated penoscrotal transposition and a hypoplastic penis and prostate at MR imaging Sagittal T2-weighted image shows a high-signal-intensity tubular structure between the urethra and the rectum, which may represent a urogenital sinus (UG). The distal urethra opens into the perineum in the ventral aspect of the corpus spongiosum (arrow). P - prostatic urethra, UT -utricle
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
*Posterior urethral valves
- It is also referred as congenital obstructing posterior urethral membranes (COPUM),
are the most common congenital obstructive lesion of the urethra and a common cause of obstructive uropathy in infancy.
-Ultrasound
- Bladder is typically thick-walled and trabeculated with an elongated and dilated posterior urethra (keyhole sign)
Fig. 20: Ultrasound demonstrates a markedly distended bladder and prostatic urethra (keyhole sign) with a degree of prominence of the renal collecting systems-Features are consistent with posterior urethral valves.
References: (https://radiopaedia.org/articles/posterior-urethral-valves?lang=us)
-Voiding cystourethrogram (VCUG)
- Dilatation and elongation of the posterior urethra (the equivalent of the ultrasonographic keyhole sign)
- Linear radiolucent band corresponding to the valve (only occasionally seen)
- Vesicoureteral reflux
- Bladder trabeculation / diverticula
Fig. 21: Micturating cystourethrogram reveals marked dilatation of the prostatic portion of the urethra consistent with posterior urethral valves.
References: (https://radiopaedia.org/cases/posterior-urethral-valves-with-pyonephrosis?lang=us)
*Hinman Syndrome
- A small number of children demonstrate persistent incontinence,
repeated febrile UTI,
VUR,
high bladder storage pressures,
and very poor emptying.
- This appears to be a deeply ingrained ‘learned’ disorder of severe voluntary DSD.
- In these patients,
the urinary tract has the appearance of a patient with a neurogenic bladder.
There is hydronephrosis,
a trabeculated bladder,
reflux,
and sometimes progressive loss of renal function
Fig. 22: This cystogram shows the typical findings in a patient with Hinman syndrome: trabeculated bladder and severe reflux. (B) This voiding study in the same patient demonstrates dilation of the posterior urethra (asterisk) as a result of chronic contraction of the external sphincter during voiding.
References: (https://obgynkey.com/bladder-and-urethra/)
*Urethral diverticulum
- Urethral diverticula, or urethroceles,
are focal outpouchings of the urethra
- Acquired urethral diverticulum occurs more frequently in female patients and is rare in male patients.
- Most commonly,
it occurs in the midurethra and on the posterolateral wall rather than on the anterior wall.
-Radiographic features
- A urethral diverticulum is a cystic lesion that typically arises from the posterolateral mid/distal urethra.
It often wraps around the urethra.
It can be multilocular.
Fluoroscopy
-Voiding cystourethrography (VCUG)
Fig. 23: On this VCUG a small diverticulum fills around the urethra with voiding. It has a “saddlebag” morphology, wrapping around the urethra posteriorly, but the larger component in on the right.
References: Https://radiopaedia.org/articles/urethral-diverticulum
Fig. 24: MCU study of a male child demonstrates a cleft like filling defect at bulbomembranous junction (arrow a) suggestive of posterior urethral valve, with prominent proximal urethra (arrow b) and presence of bladder diverticulae (arrow c).
References: (Jain A, Setia V, Agnihotri S. Spectrum of Micturating Cystourethrogram Revisited: A Pictorial Assay. International Journal of Collaborative Research on Internal Medicine & Public Health. 2016 Nov 1;8(11):603).
-Double-balloon catheter urethrography (DBU)
-Ultrasound
- Ultrasound may be of particular benefit in differentiating a septated urethral diverticulum from multiple urethral diverticula when compared with MRI.
Fig. 25: Urethral diverticulum seen on ultrasound with layering of debris within it and (b) urethrogram correlate.
References: (Shaida N, Berman LH. Ultrasound of the male anterior urethra. The British journal of radiology. 2012 Nov;85(special_issue_1):S94-101)
-CT
- A urethral diverticulum may be visualized at CT as a cystic mass with wall thickening and enhancement at the level of the pubic symphysis
Fig. 26: Axial C + delayed confirms presence of contrast filled sac posterior to the urinary bladder, which tapers toward the prostatic urethra
References: Https://radiopaedia.org/cases/urethral-diverticulum-6?Lang=us
-MRI
Phased-array endoluminal MR imaging is the most accurate method for identifying and characterizing female urethral diverticula
T1
- A diverticulum or urethrocele is hypointense
T2: preferred pulse sequence
- Hyperintense fluid in a diverticulum
- Diverticulum with circumferential involvement is described as "saddle bag diverticulum"
- It may also demonstrate fluid-fluid levels
T1 c+ (gd)
- It can also aid in the diagnosis of the rare diverticular adenocarcinoma
- Malignancy can be visualized as enhancing soft tissue within the diverticulum
Fig. 27: MRI Sag T2 Fat sat images of the pelvis demonstrates on the posterior side of the urethra a fluid-filled thin-walled structure. It appears to communicate the the lumen of the urethra (best seen on the axial T2 images). The base of the bladder and the adjacent urethra are displaced.(Urethrocoele U)
References: (https://radiopaedia.org/articles/urethral-diverticulum)
Fig. 28: Infected urethral diverticulum in elderly woman. Axial T2-weighted image shows a fluid-fluid level (arrow) in a diverticular sac
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Inflammation
- In female patients,
urethral inflammation often occurs in combination with cystitis and vaginitis or may follow radiation therapy.
Urethral diverticulum,
periurethral inflammation,
and sinus tracts are thought to result from inflammation of the Skene glands.
- In men,
sexually transmitted urethral infection including gonococcal disease used to be the most common cause of urethral stricture.
-At MR imaging
- Urethral and periurethral inflammation is seen as diffuse thickening of the urethra and periurethral tissues with intermediate signal intensity on T2-weighted images
- A periurethral abscess is seen as a cavitary lesion along the course of the urethra .
- A periurethral sinus tract may have similar MR imaging findings but may demonstrate an opening to the perineum
Fig. 29: . Urethral and periurethral inflammation with microabscesses of the Skene glands in a 27year-old woman. Coronal T2-weighted image shows periurethral infiltration with loss of surrounding fat planes (arrows). F -Foley catheter, M -microabscesses.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Fig. 30: Periurethral sinus tract in a 49-year-old woman. Axial T2-weighted images show an elongated, crescentic cystic lesion (arrow) along the right posterolateral aspect of the urethra. The lesion resembles a urethral diverticulum.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Fig. 31: Radiation-induced urethritis in an elderly woman with uterine cervical carcinoma. F - Foley catheter. Sagittal T2-weighted image shows that the entire urethra (arrows) is enlarged and has high signal intensity
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
*Urethral injury
- Urethral injury occurs as a result of blunt or penetrating trauma or iatrogenic injury.
Of the female urethra,
injuries to it are extremely rare.
- The male urethra is much more commonly injured than the female urethra because of the mobility and short length
Goldman classification of urethral injuries
This classification is a more widely accepted.
It is based on the anatomical location of the urethral injury
-Type I:
- Stretching of the posterior urethra due to disruption of puboprostatic ligaments,
though the urethra is intact
Fig. 32: Intact but stretched posterior urethra following blunt trauma (type I urethral injury). (a) Retrograde urethrogram reveals stretching of the posterior urethra. Diastasis of the pubic symphysis was diagnosed. (b) Drawing illustrates type I urethral injury.
References: Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.)
Type II:
- Posterior urethral injury above urogenital diaphragm
Fig. 33: Posterior urethral rupture above the intact urogenital diaphragm following blunt trauma (type II urethral injury). Complete type II urethral injury. Retrograde urethrogram shows a large amount of contrast material extravasation without flow into the prostatic urethra or bladder. Fracture of the right pubic ramus was diagnosed. (b)Drawing illustrates type II urethral injury.
References: Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.
Type III:
- Injury to the membranous urethra,
extending into the proximal bulbous urethra (i.e.
With laceration of the urogenital diaphragm)
Fig. 34: Posterior urethral rupture extending through the urogenital diaphragm to involve the bulbous urethra following blunt trauma (type III urethral injury). (a) Retrograde urethrogram reveals contrast material extravasation at the membranous urethra (arrow). The contrast material extends below the urogenital diaphragm and surrounds the proximal bulbous urethra. (b) Drawing illustrates type III urethral injury.
References: Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.
Type IV:
- Bladder base injury involving bladder neck extending into the proximal urethra Internal sphincter is injured,
hence the potential for incontinence
Fig. 35: Type IV urethral injury from blunt trauma. (a) Retrograde urethrogram reveals extraperitoneal periurethral contrast material extravasation at the bladder neck (arrow). The bladder is pear shaped, indicative of perivesical hematoma. Diastasis of the pubic symphysis was diagnosed. (b) Drawing illustrates type IV urethral injury.
References: Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.
Type IVa:
- Bladder base injury,
not involving bladder neck
Fig. 36: (a) Retrograde urethrogram obtained in a 32-year-old man with bladder base injury following blunt trauma (type iva urethral injury) shows extraperitoneal contrast material extravasation that extends from the elevated bladder base and surrounds the proximal urethra. Fracture of the superior and inferior pubic rami bilaterally was diagnosed. (b) Drawing illustrates type iva urethral injury.
References: Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.
Type V:
- Anterior urethral injury (isolated)
Fig. 37: Anterior urethral injury following blunt trauma (type V urethral injury). (a) Retrograde urethrogram demonstrates complete disruption of the proximal bulbous urethra with extensive venous intravasation. (b) Drawing illustrates type V urethral injury.
References: Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.
*Urethral stricture
- Urethral strictures are relatively common and typically occur either in the setting of trauma or infection (most commonly seen in Gonorrhea)
-Fluoroscopy
- Retrograde urethrography is the primary method used to image anterior urethral stricture.
-Ultrasound
- Sonourethrography is best used adjunctively to guide treatment planning in patients with known bulbous urethral strictures and has been reported to be more accurate than retrograde urethrography for estimating the length of urethral strictures.
Fig. 38: Gonococcal urethral stricture. Retrograde urethrogram reveals a segment of irregular, beaded narrowing in the distal bulbous urethra with opacification of the left Cowper duct (arrow).
References: Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.
Fig. 39: Urethral stricture seen using the descending ultrasound technique in (a) longitudinal and (b) transverse planes.
References: (Shaida N, Berman LH. Ultrasound of the male anterior urethra. The British journal of radiology. 2012 Nov;85(special_issue_1):S94-101)
*Fistula
- Urethral fistulas may communicate with the perineum,
vagina,
rectum,
and seminal vesicles and the skin of the thigh and gluteal muscles.
- Urethrovaginal fistulas most commonly occur following pelvic surgery.
Radiation,
vaginal delivery,
and inflammation may also result in fistulas.
- At MR imaging,
a fistula can be seen as a direct communicating channel with an adjacent organ
Fig. 40: In a patient with known pulmonary and renal tuberculosis Dynamic retrograde urethrogram with injection of contrast medium into the catheter (arrow) in the fossa navicularis shows a perineal fistula. A second catheter (curved arrow) is inserted into the perineal fistula orifice. Injection of both catheters simultaneously outlines a urethroperineal absceas cavity and scarred urethra. Calcification is seen in the epididymis
References: Dunnick R, Sandler C, Newhouse J. Textbook of uroradiology. Lippincott Williams & Wilkins; 2012 Oct 16.
URETHRAL CALCULI
- Urethral calculi are an uncommon type of urolithiasis,
accounting for ~1% of all urinary tract stones.
- They almost all occur in males with two peak incidences - one in childhood and the other at 40 years.
- Most impact in the prostatic urethera although ~40% (range 30-50%) are found in the anterior urethra
Fig. 41: Dynamic retrograde urethrogram showingseveresc:arringin the bulbous urethra. The filling defect (arrow) in the dilated urethra proximal to the Kairin.g.ia a ureth:raj. Stone.
References: Dunnick R, Sandler C, Newhouse J. Textbook of uroradiology. Lippincott Williams & Wilkins; 2012 Oct 16.
URETHRAL TUMORS
*Benign Tumors of the Urethra
- Benign tumors of the urethra are very rare.
- They may be of epithelial or mesenchymal origin and manifest as filling defects,
with biopsy often being necessary to establish the correct diagnosis.
-Fibroepithelial polyp of the male urethra
-Papilloma
Fig. 42: The viral papilloma demonstrated on the ultrasound study(b) longitudinal and (c) transverse planes which was overlooked as a bubble on the contrast urethrogram.
References: (Shaida N, Berman LH. Ultrasound of the male anterior urethra. The British journal of radiology. 2012 Nov;85(special_issue_1):S94-101)
*Malignant urethral cancer
- Primary urethral cancer,
in most cases a urethral carcinoma,
is a rare urological malignancy
- It can be divided in
-Female urethral cancer
-Male urethral cancer.
- It usually manifests in the fifth decade of life.
Location
- -In males most commonly involves bulbomembranous urethra(60%)> penile urethra (30%)>prostatic urethra (10%).
- In females,
the anterior segment (distal two thirds,
stratifed squamous epithelium) is involved in 46% of the cases.
The posterior segment (proximal third, stratifed squamous epithelium) is responsible for the remainder of cases.
*URETHRAL TUMORS IN MEN
• TCC
-Prostatic urethra
• Adenocarcinoma
-Glands of Li~
-Cowper's glands
• Squamous cell carcinoma
-Anterior urethra
-Area of old stricture (75% of cases)
· Leiomyosarcoma of the urethra: rare
· Melanoma of the urethra
· Adenomatous polyp of urethra
· Rhabdomyosarcoma: rare
Radiographic features
-MRI
MRI is most sensitive and specific for local extension.
· T1
- low signal mass
- difficult to differentiate from urethra
· T2
· T1 C+ (Gd)
Fig. 43: Squamous cell carcinoma of the male urethra.
A: Retrograde urethrogram shows a long irregular stricture in the bulbous urethra. B: Sagital Tl postcontrast image showing a poorly marinated soft-tissue mass in the corpus spongiosum (arrow) C; coronal T2 D: Coronal Tl postcontrast image
References: Dunnick R, Sandler C, Newhouse J. Textbook of uroradiology. Lippincott Williams & Wilkins; 2012 Oct 16.
Fig. 44: Adenocarcinoma arising from the Cowper gland in an elderly man.
(a) Axial t2weighted image shows a multilobulated soft-tissue mass of intermediate signal intensity (arrows) in the left side of the membranous urethra within the urogenital diaphragm. An enlarged left inguinal lymph node (N) is also seen. (b) Coronal T2-weighted image shows that the distal prostatic urethra (U) is displaced by the tumor (arrows)
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
*URETHRAL TUMORS IN WOMEN
-Squamous cell carcinomas.
(distal two-thirds.)
-Tccs (proximal urethra)
-Adenocarcinomas(proximal urethra)
-Undifferentiated carcinomas,
an extremely rare mucinous adenocarcinoma,
sarcomas and malignant melanomas may also Occur.
- Carcinomas presenting in the distal one third of the urethra are classified as "anterior" urethral tumors and are usually low-grade tumors with early presentation and good prognosis.
- Tumor involving the proximal two-thirds of the urethra are classified as entire urethral tumors and are of more advanced grade become apparent later and have a less favorable prognosis.
- The diagnosis of urethral tumor in a woman is usually clinical.
MRI is useful in staging these tumors once the diagnosis has been established
Fig. 45: A: Coronal T2-weighted image. B: Sagittal T2-weighted image shows TCC involving the Bladder neck and proximal urethra in a female.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Fig. 46: Clear cell adenocarcinoma of the upper two-thirds of the urethra in a elderly woman. Sagittal T2-weighted image shows a tumor of heterogeneous high signal intensity (T) that involves nearly the entire length of the urethra and the base of the bladder.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
Fig. 47: Malignant melanoma in elderly woman. Axial T2-weighted image shows an ill-defined mass of intermediate signal intensity (arrows) in the distal urethra. The mass infiltrates into adjacent periurethral soft tissues.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
v *Metastatic Tumors of the Urethra
- Secondary tumors of the male urethra are uncommon.
Bladder transitional cell carcinomas may spread to the anterior urethra by means of seeding during urethral instrumentation or at cystectomy;.
- Contiguous spread of carcinoma of the prostate,
rectum,
spermatic cord,
and testis may involve the corpus spongiosum,
which causes extensive urethral narrowing and irregularity.
- Hematogenous metastases to the corpora cavernosa and corpus spongiosum are occasionally seen with malignant melanoma and primary prostate,
bladder,
colonic,
testicular,
and renal malignancies.
- Erosion into the urethra from metastases to the corpus spongiosum may produce urethral irregularities.
Fig. 48: Urethral metastasis from prostate carcinoma. Retrograde urethrogram shows a segment of smooth extrinsic narrowing of the bulbous urethra. Note the skeletal metastases.
References: (Kawashima A, Sandler CM, Wasserman NF, leroy AJ, King Jr BF, Goldman SM. Imaging of urethral disease: a pictorial review. Radiographics. 2004 Oct;24(suppl_1):S195-216.)
Fig. 49: Urethral and periurethral invasion from recurrent cervical cancer in a 75-year-old woman. (a) Axial T2-weighted image shows an irregular soft-tissue mass of intermediate signal intensity (arrows) surrounding the urethra (U). The outer ring of the urethra is disrupted in the left anterolateral portion (arrowhead), suggesting invasion of the outer muscle layer. (b) Sagittal T2-weighted image shows that the uterine cervix is shrunken and the vagina is diffusely thickened, probably due to post–radiation therapy changes. Residual tumor (arrow) is seen in the upper anterior aspect of the thickened urethra (U) at the bladder base.
References: (Ryu JA, Kim B. MR imaging of the male and female urethra. Radiographics. 2001 Sep;21(5):1169-85.)
*POSTOPERATIVE URETHRAL CHANGES
Urethroplasty
- Urethroplasty,
particularly two-stage procedures perfomed as definitive therapy for anterior urethral strictures,
may result in saccular dilations of the urethra,
particularly near the proximal and distal ends of the repair.
- These sacculations may be so large as to resemble urethral diverticula.
Because of their size,
they may c:ollect urine during voiding and cause postvoid dribbling.
Retrograde urethrography easily demonstrates sacculations or acquired diverticula.
Fig. 50: Posturethroplasty sacculations. Retrograde urethrogram using Brodney clamp shows two saccular dilations of the mid anterior urethra in a. Patient who has undergone urethroplasty for ure1hral stricture
References: Dunnick R, Sandler C, Newhouse J. Textbook of uroradiology. Lippincott Williams & Wilkins; 2012 Oct 16.