Vision of Urethral Disease: A Pictorial Review
Therein article, we review the habitus and diseases of the urethra in adults. Although we core formal urethrography, we discuss and represent the key resource features of urethral diseases at both urethrography and cross-sectional imagery. The article is nonionised as follows: (a)convention pattern of the urethra, (b)urethrographic techniques, (c)traumatic injuries, (d)acquired incitive diseases, (e)urethral strictures, (f)acquired female urethral diverticula, (g)urethral calculi, and (h)radical and metastatic tumors. Because the accentuate of this article is on the big urethra, we do not discuss unconditioned anomalies.
Conventionality Form of the Urethra
The manly urethra varies from 17.5 to 20 cm in length and consists of anterior and arse portions, each of which is subdivided into two parts. The anterior urethra extends from the immaterial meatus to the substandard cigarette of the urogenital closure, coursing through the main spongiosum. The anterior urethra is conventionally divided into the penile (or pendulous) and bulbous parts at the penoscrotal junction on the foundation of clinical and imaging findings. The cernuous portion terminates in the glans member to mannequin the pit navicularis, which is 1–1.5 cm hanker. The proximal packet of the bellying urethra is dilated and termed the “sump” of the bulblike urethra; just proximal to the cesspool, the bulbous urethra assumes a conic form at the bulbomembranous junction. This service of the myelin is known as the “cone.” The anterior urethra has periurethral Littré glands, which are more numerous at the dorsal aspect of the penile urethra and in the bellied urethral sump. The Cowper glands are two pea-sized glands that lie inner the urogenital closure on each english of the membranous helping of the ass urethra. The ducts of the Cowper glands are 2 cm farsighted and empty into the bulgy urethral cesspit on either aspect of midline.
The ass urethra is divided into the prostatic and membranous urethras. The prostatic urethra is about 3.5 cm languish and passes through the prostate slightly anterior to midline. A longitudinal ridge of finish brawniness (urethral visor) extends from the bladder neck to the membranous urethra on the bottom groin of the merchantman urethra. This longitudinal ridge continues into the verumontanum, a 1-cm-long elliptical pitcherful that lies in the behind wall of the prostatic urethra. In the center of the verumontanum lies the prostatic utricle, a small saccular low that is a vestigial remaining of the müllerian line. Just distal and asquint to the utricle are the orifices of the opponent ejaculatory ducts. The prostatic glands overturn calculate into the prostatic urethra via multiple minor openings that evade the verumontanum. The prostatic urethra so tapers distally into the membranous urethra, which is around 1–1.5 cm long and ends at the wanting panorama of the urogenital diaphragm.
The proximal (home) urethral sphincter extends from the bladder neck through the prostatic urethra above the verumontanum. Although it is similar to the detrusor brawn, it has different neurogenic provocation. The distal (impertinent) sphincter has both intrinsic and extrinsic components. The “intrinsic” urethral sphincter is a concentric musculature and lies in the distal one-third of the prostatic urethra downstair the pitcherful of the verumontanum and surrounds the membranous urethra. Both the internal and intrinsic sphincters are composed of radiance muscle and use as muscles that assert peaceable continence. The inside sphincter functions as the uncomplicated continence sphincter and the intrinsic sphincter as the subaltern continence sphincter. The extrinsic sphincter is a paraurethral, striated, offer heftiness with contributions from the levator ani complex. The sphincter surrounds the membranous urethra and is involved in fighting continence.
The female urethra is 4 cm longsighted and extends from the bladder neck at the urethrovesical junction to the lobby, where it forms the foreign meatus ‘between the labia minora. Many modest periurethral glands open into the urethra. Distally, these glands group together on either side of the urethra (Skene glands) and void through two modest ducts to either incline of the exterior meatus. The proximal leave-taking of the urethral environment is made up of two layers of culture heftiness that are neighboring with the tranquil muscle of the bladder neck. The home layer of the smooth muscle is longitudinal, and the diluent outer level is pecker. The outer serving of the urethra is composed of striated sinew, which, in the speed two-thirds of the urethra, is primarily tirade and extends proximally to blend with the bladder founding. The lower dowery of the urethra is nearly located next to the anterior vaginal wall and enveloped by commons musculature (the urethrovaginal sphincter), which extends to the inferior pubic ramus above the urogenital diaphragm.
Retrograde urethrography is considered to be the outmatch initial correction for urethral and periurethral resourcefulness in men and is indicated in the rating of urethral injuries, strictures, and fistulas (1,2 ). Retrograde urethrography is a honestly, promptly available, cost-effective examination. The away meatus is prepared in a measure stereotyped way for the location of a effected 16- or 18-F Foley catheter. The catheter, with both the irrigating syringe and inflating (saline) syringe attached, should be red onward use. When the amplify function of the catheter is session in the pit navicularis of the penile urethra, the amplify is high-flown with 1.0–1.5 mL of saline mend the port is held with the release bargain to part inflate the wallow (2 ). Lubrication is not recommended because it may foresee the billow from left-hand in office for optimal stop. The patient is set in a supine 45° roundabout billet. The appendage should be set laterally concluded the proximal thigh with trail clutches. The patient should be reassured some the annoying that is experienced during inflate pomposity. So, 20–30 mL of 60% iodised contrast actual is injected under fluoroscopic counselor so that the anterior urethra is filled. Usually, strangle of the exterior urethral sphincter will be encountered, which prevents weft of the deep bulbar, membranous, and prostatic urethras. Dim, conciliate wardrobe is ordinarily requisite to whelm this resistance. Spot radiographs are obtained when there is visual confirmation of line cloth satiny into the bladder.
If correct administered, limit cloth can be seen to jet through the bladder neck into the bladder. The verumontanum is seen as an ovoid filling defect in the merchantman part of the prostatic urethra. The distal end of the verumontanum marks the proximal boundary of the https://sarahwilliamsart.com/ membranous urethra, which is approximately 1 cm ache and is that dowery of the urethra that passes through the urogenital midsection. This is besides the share of the impertinent sphincter of the urethra. The distal sharpness of the membranous urethra (the bulbomembranous juncture) is the strobilus of the bulbar urethra. The naming of the bulbomembranous conjunctive on a retrograde urethrogram is alert classic for assessing patients with urethral disease too as for purvey urologic procedures. When the bum urethra is optimally opacified and the verumontanum visible, the bulbomembranous spliff can be identified 1–1.5 cm distal to the substandard border of the verumontanum. When the ass urethra is suboptimally opacified, the bulbomembranous junction can be randomly localized where an conceptional job connecting the inferior margins of the obturator foramina intersects the urethra.
The anterior urethra extends from its bloodline at the end of the membranous urethra to the urethral meatus. It is divided into the bulbar (almost proximal) segment and the penile (pendulous) subdivision. There is unremarkably pocket-size angulation of the urethra where these two segments wed at the penoscrotal conjunction. Compaction or halter of the constrictor nudae muscle, a cryptical musculotendinous sling of the bulbocavernous heftiness, may cause anterior or, less frequently, circumferential indentation of the proximal bulbous urethra at regression urethrography (3 ). This bellied urethral indention should not be illogical with urethral stricture (Fig 1 ). If the membranous urethra can be identified, it leave not be garbled with a stricture. Narrowing elsewhere in the urethra will be crystalise defined as separate from the membranous urethra and, accordingly, representative of a pathological stricture. If the patient is not positioned sufficiently shifty, the bulb-shaped urethra will aspect foreshortened and will so not be adequately evaluated ( Fig 2 ). Selection of the Cowper ducts should not be misinterpreted as clap (Fig 3 ). Opacification of the prostatic ducts, Cowper ducts, and periurethral Littré glands is oft, but not necessarily, associated with urethral inflammatory and stricture disease. If the oneness of the urethral mucosal lining is disrupted by increased press during contrast fabric injection, intravasation of contrast material with opacification of the corpora and wearying veins may hap.
Excreta cystourethrography is soon the astir ordinarily exploited resource method in the rating of the female urethra and manly bottom urethra. Excretion urethrography is unremarkably performed aft the bladder is filled with business material via a transurethral or suprapubic catheter. After the transurethral catheter is withdrawn, the patient voids chthonic fluoroscopic rumination and smear radiographs of the bladder and urethra are obtained. During active riddance, the bladder neck opens all-encompassing and becomes funnel wrought in both manly and female patients by way of the versed sphincter mechanism. In manlike patients, the verumontanum appears stretch and the proximal bulbar urethra has a less conical appearance. Notwithstanding, the membranous urethra remains the narrowest part ‘between these parts of the urethra, gush though it may enlarge able 6 or 7 mm in diameter during excretion. Excretion cystourethrography may not demonstrate certain abnormalities of the manlike anterior urethra because the pattern anterior urethra is not wide-cut distended to the degree seen at retrograde urethrography.
A retrograde study is the well-nigh appropriate way to measurement the anterior spot of the urethra, and a excreting study is the dear beguile way to evaluate the arse role of the urethra; so, “dynamic” urethrography represents a synergy of these two imaging techniques.
Blunt Urethral Injury
Desolate urethral injury traditionally has been classified anatomically as either anterior or merchantman offend. Bum urethral scathe commonly is caused by a stifling lastingness to the hip (eg, from a high-speed car solidus) and is associated with pelvic fractures. Bum urethral offend has been reported to hap in 4%–14% of patients with pelvic jailbreak (4 ). In pelvic breaking, subject 20% of male patients with urethral harm too hurt associated bladder laceration. Conversely, anterior urethral harm normally results from a bridge pelvic injury and is almost ofttimes set-apart. When there is lineage at the meatus, which is present in about one-half of fraught urethral injuries, retire urethrography should be performed instantaneously to value for urethral injury. Blind urethral catheterization is contraindicated in patients suspected of having urethral harm because the catheter could be misplaced into a pelvic hematoma through a urethral hurt spot. When urethral injury is demonstrated, a suprapubic catheter should be placed for spry endoscopically assisted stent placement or delayed reconstruction procedures.
In 1977, Colapinto and McCallum (4 ) classified bum urethral injuries into lead types on the stand of findings at recidivate urethrography. In type I distress, there is gap of the puboprostatic ligaments. Although the prostatic urethra is stretched, the perseverance of the urethra is shipshape ( Fig 4 ). In case II scathe, the membranous urethra is lacerate above an sacrosanct urogenital blockage, which prevents contrast somatic irruption from extending into the perineum ( Fig 5 ). Type II injuries get been reported to interject 15% of cases (4 ). In type III detriment, the nigh common model of urethral damage, the membranous urethra is ruptured but the suffering extends into the proximal protuberant urethra because of laceration of the urogenital block ( Fig 6 ). Persona III urethral harm is characterized at urethrography by line material clap not sole into the pelvic extraperitoneal spa but too into the perineum. Goal breakage of the potent membranous urethra, which occurs in both lawsuit II and III urethral damage, may resoluteness in perturbation of the bladder out of the hip, which appears as “pie in the sky” at excretory urography. Although the Colapinto and McCallum categorization organization is described as classifying ass urethral injuries, persona III harm very extends into the bulging portion of the anterior urethra. Type II and III injuries may be associated with incontinence related traumatic suffering to the immaterial sphincter. Ali et al (5 ) belatedly reported computed tomographic (CT) findings in urethral injuries. In fiber III urethral suffering, CT demonstrates urinary contrast bodily clap at and below the urogenital diaphragm.
In 1997, Goldman et al (6 ) proposed a new unified categorization arrangement for urethral injuries future blunt scathe based on the anatomic locating of the hurt. The new categorization establishment modifies and extends the Colapinto and McCallum dodging (geek I–III injuries) into phoebe types, with the addition of bladder bag injuries (geek IV and IVa injuries) ( Fig 7 ) and straddle anterior urethral lesion (vitrine V injury). Bladder founding injuries were believed to be of item aid because the bladder neck is the spot of the inside sphincter, which is the boss continence sphincter. Goldman et al suggested that patients with these injuries be considered for running therapy because there is the potential for incontinence if harm of the internal urethral sphincter is not apprehended. In addition, a warrant part of injury (role IVa hurt), extraperitoneal bladder teardrop at the fundament of the bladder that does not extend into the bladder neck, was included because it was believed that the clap from a laceration therein locating would simulation a true part IV urethral damage ( Fig 8 ). Because type IVa injuries do not extend into the bladder neck, there is less trouble for dissoluteness as a result of impairment to the suggest sphincter; these injuries may be managed nonsurgically with bladder catheter enfeeble good. On the terms of the radiographic findings, extension of detriment into the bladder neck and proximal urethra cannot be excluded, and type IVa urethral injuries are radiologically monovular from lawful type IV injuries.
Traumatic gap of the female urethra is elevated. Perry and Husmann (7 ) appoint lawsuit IV urethral injuries in 4.6% of women with pelvic shift caused by high-speed ride vehicle accidents. Roughly reported cases let occurred in girls or young women. Snatch of the urethra should be suspected when derivation is present at the impertinent meatus or there is encroach vaginal laceration (part IV injury). The urethra may be avulsed at or interior 2 cm of the bladder neck ( Fig 9 ).
Cause V urethral injuries are caused by bridge damage and hap in the bellying urethra ( Fig 10 ). The bellying urethra and main spongiosum are besotted ‘between the operose object and the lacking aspect of the pubic clappers. This conglutination may root in urethral hurt with an sacrosanct urethra or partial or communique prisonbreak of the cesspit of the bulging urethra. Loosely, a compass urethral scathe is not associated with a os injury. If the Sawhorse splasher clay inbuilt, the burping is extra to the spa between the Buck fascia and the tunica albuginea of the head spongiosum. If the Clam fascia is ruptured, clap of contrast hooey will be birth within the confines of the Colle fascia at urethrography.
Master reconstruction of urethral breaking is preferred at 3–6 months, when the scar thread at the urethral scathe is static and fester and associated injuries corroborate been stabilized (8 ). Conterminous open head realignment of the urethral distraction is associated with a high rate of morbidity. Yet, selected patients suspected of having tender din can be case-hardened by delegacy of adjacent “indirect,” carefully performed endoscopically and fluoroscopically assisted stent placement with a urethral catheter (8 ). Afterwards complications associated with ass urethral harm acknowledge impotency, incontinence, stricture (Fig 11 ), and fistula (Fig 12 ), whereas those associated with anterior urethral lesion include stricture and powerlessness.
Piercing Urethral Injuries
Acute urethral injuries from gunshot or spit wounds are rarified and more commonly pretend the anterior urethra (Figs 13. 14 ). Urethrography is indicated for all patients with ague penile impairment because able one-half of these patients have urethral injury. Broadly, piercing injuries need adjacent shamus exploration and antibiotic therapy to command superimposed infection. Gunshot wounds may crush some urethral tissues, and patch or pedicle grafting may be required. Massive meander injury is close suitable for ordered shamus treatment. Mostly, clapper wounds to the perineum can be treated with in situ fix of the lacerated bulblike urethra.
Urethral Wounding in Penile Breaking
Prisonbreak of the star cavernosum from harm to the intumescent penis (“penile fracture”) is an rarified wounding and normally occurs during hard sex. The patient experiences knifelike trouble, and the appendage becomes deformed and ecchymotic. Penile chemise is associated with urethral hurt in 38% of patients, and relapse urethrography is commonly recommended to bar a consequent urethral scathe (Fig 15 ). Magnetic vibrancy (MR) imaging is useful when the clinical presentation is atypical because it can appropriate exact position of the offend and perspicacity of the injured corpora cavernosa (9,10 ). Cavernosonography with the pellet of 30% iodised pipeline textile into the corpora cavernosum followed by fluoroscopy and discolouration radiography may show the ask billet and extent of the tunica albunigea rub (11 ). This randomness may be useful because the site of a tunica albuginea rip may not be obvious at or. A urethrocavernous fistula may hap in the fractured member and can be demonstrated at cavernosonography.
Urethral complications following actinotherapy (outside scape and radiotherapy reference imbed brachytherapy) take urethritis, urethral stricture, and urethral fistula (12 ). The latter is a grievous contortion of radiation treatment. Prostatic urethrorectal fistula has been reported to enter 1% of patients after prostate brachytherapy for prostate cancer ( Fig 16 ) (13 ).
Urethral Upset aft Pancreas Transplantation
Bladder debilitate of pancreatic transplanting exocrine secretions is a common technique in pancreas transpose. One of the urologic complications of coincidental kidney-pancreas transplant with bladder drainpipe in virile patients is urethral injury and disruption, with urinary irruption occurring in 6% of cases (14,15 ). The urethral injury is attributed to activated proteolytic exocrine enzymes from the transplanted pancreas. Child urethral scathe due to transurethral catheterization or cystoscopy appears to ontogenesis the risk of exploitation urethral scathe related pancreas transplantation. Urethral hurt should be considered when dysuria persists and results of piss assimilation are blackball. Crawfish urethrography is the imaging method of alternate for making the diagnosis and typically demonstrates contrast veridical belching at the bellying urethra and bulbomembranous articulation (Fig 17 ). Short-term transurethral catheterization or suprapubic catheter drainpipe usually leads to resolution.
Acquired Arsonist Diseases
Gonococcal and Ngu
Gonococcal urethritis is associated with the gram-negative diplococcus, Neisseria gonorrhoeae. Although gonorrheal contagion has case less prevalent since the early 1980s, it clay the leash reportable elvis in adults in the United States. Patients with gonococcal urethritis usually drink with snatch urethral sacking. Lull, ngu is increasing in oftenness. Chlamydia trachomatisis the virtually common pathogen of ngu, accounting for 30%–50% of cases. Urethral liberation associated with ngu is usually lighter. The diagnoses of piercing gonococcal or ngu are normally made by essence of clinical and lab findings. No resource studies are required for noncomplicated urethritis. Complications associated with gonococcal urethritis are more cant and more sombre than those associated with ngu and include urethral stricture, periurethral abscess, and periurethral fistula.
The classifiable urethrographic finding in gonococcal urethral stricture is an irregular urethral tapering various centimeters eagle-eyed (Fig 18 ). An estimated 15% of men with gonococcal urethritis bechance to break stricture, with an detachment of 2–30 years between transmission and the bombardment of clogging symptoms. With adequate antimicrobial dissertate, however, the frequency of stricture associated with ngu is believed to be first-rate low (16 ). Arduous ropey scars are present at the distal portion of the bellied urethra in 70% of patients. These scars are due to less effective flushing by urination and the preponderance of Littré glands therein sphere. Associated distension of Littré glands may be present at urethrography. If the proximal cone-shaped bulbar urethra appears to be narrowed, elongated, crooked, guerilla, or deficient, the stricture is seen to diversify into the membranous urethra in more 90% of cases (17 ). This radiologic purpose is of bloom richness to the urologist because shamus preaching may exact cutting the pit tissue and, consequently, the distal sphincter, which could resolvent in iatrogenic self-gratification. Urethroscopic or open working interventions are ordinarily mandatory to assuage clogging symptoms (eg, hard to nihility, timid sprout, and a touching of incomplete emptying of the bladder) junior-grade to urethral strictures. In selected cases, intraluminal stent position may be legal for treating urethral stricture (18 ). (See too the section entitled “Strictures of the Urethra.”)
Periurethral abscess is a serious transmission of the manly urethra and periurethral meander and frequently a sequela of gonococcal transmission, urethral stricture disease, or urethral catheterization. Periurethral abscess arises initially when a Littré gland becomes obstructed by inspissated pus or fibrosis. The most gross infecting organisms are gram-negative rods, enterococci, and anaerobes. Pseudodiverticulum constitution results from urethral communication with a periurethral abscess. Because the adventitia albuginea of the penis prevents the dorsal gap of transmission, the abscess tends to track ventrally on the main spongiosum, where it is confined by the Dollar splashboard. However, when the Buck fascia is perforate, there can be all-encompassing necrose of the hypo waver and fascia. Roughly 10% of periurethral abscesses drain extemporaneous. Rapid diagnosis and give-and-take are requisite. Imaging studies may be indicated if the diagnosis is not effected clinically. An abscess that drains into the urethra may be demonstrated at urethrography (Fig 19 ). Echography (US) can establish the comportment of periurethral abscess, and CT and MR imaging are helpful for assessing the extent of the periurethral abscess and complications such as fasciitis and Fournier gangrene. Treatment consists of spry suprapubic urinary drainage, encompassing surgical abscess debridement, and judiciary of seize antibiotics.
Urethroperineal fistulas are most often the burden of a periurethral abscess. Mostly, the initial abscess pit contracts by gist of alterative fibrosis, which leaves lone the specialise fistular footpath from the urethra to the perineum. So, urination unremarkably occurs through the perineal fistulas, which results in the supposed “watering can perineum” ( Fig 20 ) (19 ). Urethroperineal fistulas are ordinarily the consequent of tb and schistosomiasis infections.
Condyloma acuminata are caused by viral transmission and produce easygoing, sessile, squamous papillomas on the penile glans and rooster and the prepuce. Condyloma acuminata are termed venereal warts. Urethral involvement occurs in 0.5%–5% of virile patients. Occasionally, condyloma acuminata may signature the prostatic urethra and bladder. The use of catheterization, instrumentation, and retrograde urethrography is not recommended because of the possibility of recidivate seeding. The diagnostic outgrowth of tone is liquidation cystourethrography. Nevertheless, the diagnosis is often not suspected until retrograde urethrography has been performed. The classifiable urethrographic findings are multiple papillary fulfill defects in the anterior urethra (Fig 21 ). Urethral lesions are treated with the instilment of podophyllin, thiotepa, or 5-fluorouracil into the urethra.
T.b. of the urethra is selfsame elevated. Normally, genital tb is a descending transmission and renal t.b. is discernable. The prostate is knotty in 70% of patients with genital t.b.. Prostatic abscess may bust into any encompassing twist, which results in prostatorectal and prostatoperineal urethral fistulas. In the keen shape, there is urethral discharge with associated concern of the epididymis, prostate, and otc parts of the urinary arranging. The diagnosis is made at clinical examination, and administration of antituberculous agents should be initiated. In the chronically mannequin, diagnosis becomes difficult because patients wassail with impeding symptoms niggling to urethral strictures. Lunger urethral strictures effect in periurethral abscesses, which, unless toughened, assume host perineal and scrotal fistulas. The end result is tearing can perineum. Retrograde urethrography typically demonstrates an anterior urethral stricture associated with multiple prostatocutaneous and urethrocutaneous fistulas. Simultaneous fistulography may be useful for assessing the inherent urethra because virtually cable framework exits the urethra through the urethroperineal fistulas, which may foresee visualization of the inviolate urethra.
Strictures of the Urethra
Loosely, the depot urethral stricturerefers to a powerful scarring of the anterior urethra caused by collagen and fibroblast proliferation (17,20 ). Associated cicatrice in the encompassing dealer spongiosum is known as spongiofibrosis. The scarring surgery can stretchability through the meander of the corpus spongiosum and into conterminous structures. Capsule of this cicatrix reduces the comprehensiveness of the urethral lm. The causes of anterior urethral strictures may be instigative (eg, morbific urethritis, balanitis xerotica obliterans), traumatic (couplet harm, iatrogenic instrumentation) or inbred. Near urethral strictures are the resolve of transmittal, instrumentation, or other iatrogenic causes. The near common external fight of traumatic stricture is duad hurt. Firebomb strictures associated with gonococcal urethritis bear wooing less unwashed disrespect the fact that gonococcus remains the astir commons dot. Iatrogenic damage to the urethra may result from effect gangrene at stiff points in the urethra from indwelling catheters. Instrumentation-related strictures usually materialise in the bulbomembranous neighbourhood and, less commonly, at the penoscrotal stick.
Rather, ass urethral stricture is oftentimes an obliterative outgrowth that occurs as a reply of urethral bewitchery or prison-breaking caused by either injury or procedure. Posttraumatic ass urethral stricture is oftentimes associated with incidental extirpation of the urethral axis, which results in obliteration from intervening fibrosis. Iatrogenic stricture of the prostatic bum urethra (“bladder neck contracture”) commonly occurs after turp or extend shank prostatectomy (21 ).
Relapse urethrography is the primary method victimised to picture anterior urethral stricture (17 ). Radiographic paygrade helps delimit the locating, space, twist, and detail of strictures likewise as the periurethral abnormality—important factors for determinant beguile preaching. The length of the stricture willing be underestimated if the find more about patient is not placed in a swallow circuitous spot for reversion urethrography. More one jut may be prerequisite to build the stricture. Sonourethrography is beaver ill-used adjunctively to guide treatment grooming in patients with known bellied urethral strictures and has been reported to be more claim than regress urethrography for estimating the continuance of urethral strictures (17,20 ). Periurethral fibrosis manifests at US as callous, maverick, nondistensible wander incursive into the otherwise anechoic urethral lm. When sonourethrography demonstrates asshole shadowing and a nondistensible lm diameter of less than 3 mm during maximum retrogression distention, the changes of periurethral spongiofibrosis are considered to be unsafe. Spongiofibrosis is outdo treated with functional resection.
In bum urethral strictures following dampen damage, concurrent antegrade cystourethrography and retroversion urethrography are oft mandatory to finalize the space of the urethral desolate (Fig 11 ). MR imagery is considered to be the outperform accessory imaging humor for assessing posttraumatic pelvic design (22 ). Multiplanar T2-weighted MR imaginativeness can attend valuate the billet of the prostate and the amount of pelvic fibrosis and can attend contour the aloofness of the prostatomembranous deface by allowing measuring of the distance between the prostatic meridian and urethral creation into the proximal star spongiosum (22 ).
Acquired Female Urethral Diverticula
The diagnosis of female urethral diverticula is being made with greater oftenness owe to sensation of the circumstance and of its coexistence with stress enuresis and urinary transmission. Urethral diverticulum has been reported in 1.4% of women with emphasis enuresis. Female urethral diverticulum is shortly intelligent to be acquired and is attributed to the offend of dilated and infected periurethral glands, which results in pseudodiverticulum formative. This hypothesis is supported by the fact that all urethral diverticula are contained within the periurethral fascia. Another common move is breakage of the periurethral fascia during bladder neck reprieve or for focusing incontinence, which results in focal ass urethral prolapse. Female urethral diverticula let a kinda shapes and configurations. Diverticula may be integrity or multiple, unilocular or multicompartmental. Urethral diverticula may parentage either a extensive or narrow neck and are ordinarily set posterolateral to the urethra. Urethral diverticula may circumvent the urethra (“saddle” diverticula). When a diverticulum originates from the proximal urethra, there may be a mass incumbrance on the bladder footstall likewise thereto seen in elderly men with an enlarged prostate, a finding that is referred to as the “female prostate” sign. The hellenic monstrance of urethral diverticulum has been described as the tercet Ds (dysuria, postvoid dribbling, and dyspareunia). Postvoid slobber is enclose in 25% of patients and dyspareunia in 10%. About one-half of patients will constitution a urinary footpath contagion. An anterior vaginal rampart masses may be identified at bullyrag examination, and compression of this batch may effect in pussycat release from the urethra.
The diagnosis is normally made with elimination cystourethrography or cross-sectional imaging. A wide-neck communicating diverticulum can likewise be demonstrated on a postvoiding role obtained during excretory urography (Fig 22 ) or at delayed occupation material–enhanced CT. Emptying cystourethrography has an overall verity of 65% (23 ). Double surge (positive imperativeness) urethrography is more bid than voiding cystourethrography and may let contrast binge to be labored into a diverticular ostium by creating a relatively closed urethral system in which the line textile passes into the spot by representation of concentric insistency rather than opportunist pour bending (24,25 ). Still, this technique is laborious to sketch and may be direful for patients.
Because of its multiplanar capableness, excellent wander business, and omit of ionizing beam, MR imaging is an fantabulous humour for demonstrating urethral diverticula (Fig 23 ) (26 ). MR imaging is more raw than excretion cystourethrography and two-baser surge urethrography in the detection of urethral diverticula, particularly in the staining of narrow-neck noncommunicating urethral diverticula (27,28 ). The complex appearance of urethral diverticula is max demonstrated at MR imaging performed with pelvic phased-array coils. The use of endovaginal or endorectal coils at MR imaginativeness can provide high-resolution details of urethral diverticula (29 ). Transvaginal US has too been reported to be helpful for identifying urethral diverticula in women (23,30,31 ). US can demonstrate a relatively echo-free pit immediate to the urethra and may similarly testify intracavitary debris or encompassing firebomb edema. Both US and MR imaging may generate abnormalities in coterminous structures that could be the crusade of the patient’s symptoms. The differential diagnosis of a urethral diverticulum includes vaginal cyst (Gartner transfer cyst, paramesonephric or müllerian canalize cyst, epithelial inclusion cyst), ectopic ureterocele, endometrioma, and urethral tumors (32 ).
The unambiguous manipulation of urethral diverticula is transvaginal diverticulectomy. Urethral diverticula may be complicated by infection, gem constitution (open 10% of patients), and malignant degeneracy (26 ). Adenocarcinoma is the virtually oft diagnosed tumour in female urethral diverticula (33,34 ).
Near urethral calculi harp of minor stones expelled from the bladder into the urethra during emptying; these are referred to as migrant calculi. Occasionally, withal, a pit may be lowering batch to go lodged at a billet of urethral narrowing such as the membranous urethra. Rarely, primary (native) organisation of a stone occurs in the urethra when stricture is toast, or it may be associated with a urethral diverticulum ( Fig 24 ). Symptoms of urethral gem accept washed-out pour, dysuria, and hematuria. Retrograde urethrography will ordinarily impersonate a rounded pick mistake in the urethra. On a preprocedural low ab skiagram, the pit may be identified before contrast material is injected.
Benign Tumors of the Urethra
Benign tumors of the urethra are truly elevated. They may be of epithelial or mesenchymal founding and observable as filling defects, with biopsy oftentimes existence essential to background the conform diagnosis. To our knowledge, lone one causa of chaplet of the urethra has been reported in which MR vision helped accurately fix neoplasm fix and extent (35 ). However, the MR imaging characteristics of benign tumors appear to product with those of malignant tumors. Fibroepithelial polyp of the male urethra is of embryonic descent, ordinarily originating in the prostate and projecting into the urethra (36 ). This bod manifests at line with hematuria or hindering excreting symptoms. The polyp is connected to the verumontanum via a stalk, which allows the polyp to relaxation in the prostatic urethra or eve extend through the bladder neck into the bladder. During the elimination phase of cystourethrography, the polyp typically appears as a lull choice mar extending into the mall of the bulbar urethra.
Malignant Tumors of the Manly Urethra
Tumors of the male urethra are rare, comprising less than 1% of all urologic cancers, and usually occur aft 50 years senior. The nigh k symptom at presentation is a real bargain in the perineum or on the putz of the urethra with or without obstructive excretion symptoms. Urethral stricture or haemorrhage, hindering symptoms, serosanguinous sacking, urethral fistula, periurethral abscess, or perineal pain in an elderly man is revelatory of urethral carcinoma.
Tumors of the male urethra are categorized according to their position and the histologic characteristics of the cells that cablegram the urethra. The bulbomembranous urethra is involved about oft (60% of cases), followed by the penile urethra (30%) and the prostatic urethra (10%) (37 ). Overall, 80% of manly urethral carcinomas are cancroid, 15% are transitional booth carcinoma, and 5% are adenocarcinoma or consistent carcinoma. The histologic subtype of urethral cancers similarly varies according to anatomic location. The prostatic urethra is convoluted by transitional cell carcinomas in 90% of patients and by squamous cell carcinomas in 10%. The bulbomembranous urethra is snarled by squamous stall carcinomas in 80% of patients, transitional cell carcinomas in 10%, and adenocarcinomas or undifferentiated carcinomas in 10%. The penile urethra is involved by squamous cell carcinomas in 90% of patients and by transitional cell carcinomas in 10%. Adenocarcinoma arises from the Littré or Cowper glands. Leiomyosarcoma and melanoma are elevated in both men and women (38,39 ). Causes associated with the underdeveloped of urethral cancers in men accommodate chronic liberation fiddling to sexually transmissible pathogenic urethritis and urethral stricture. More one-half of patients with a carcinoma of the urethra lose a history of urethral stricture disease, and almost one-quarter wear a account of acid. 96 pct of patients are symptomatic. Urethral carcinomas well-nigh oft involve the bulbomembranous urethra, which is too the incision usually byzantine by urethral stricture disease. A slip of lymphoma of the urethra in a patient with acquired immunodeficiency syndrome has been reported (40 ).
Manful urethral carcinoma can dissemination by organise backstage to contiguous structures or metastasize to regional lymph nodes. Set I urethral neoplasm is enwrapped to the subepithelial connexion wander. Leg II neoplasm invades the star spongiosum, prostate, or periurethral brawn. Level III tumour invades the main cavernosum and bladder neck or bey the prostatic capsulated. Leg IV tumor invades erstwhile adjacent organs. The lymphatic vessels from the anterior urethra enfeeble into the lilliputian and fertile inguinal lymph nodes and, occasionally, into the out-of-door iliac lymph nodes. Tumors of the bum urethra most commonly spread to the pelvic lymph nodes. Carcinomas of the bulbomembranous urethra may overproduction the urogenital midsection, prostate, perineum, and scrotal peel. Hematogenous dissemination is rarefied until advanced local disease is familiarize or in honcho transitional kiosk carcinoma of the prostatic urethra. Loosely, anterior urethral carcinoma is more amenable to functional bidding and has a wagerer calculate than butt urethral carcinoma, which is frequently associated with all-inclusive local violation and distant metastasis. Pi cut is the honcho interposition of character.
The diagnosis of urethral tumors is unremarkably suggested clinically at hector interrogative. Urethrography can be helpful in making the diagnosis of urethral carcinoma, unremarkably cover focal unorthodox tapering of the urethra (Fig 25 ). Urethral carcinomas may be complicated with fistulate underdeveloped. The classifiable MR purpose in urethral carcinoma is a flock with rock-bottom forecast intensity relative to the formula corporate interweave at both T1- and T2-weighted imagery ( Fig 26 ) (41 ). MR imaging can name impingement of the corpora cavernosa and is useful for demonstrating tumor billet and size and local staging (38,42,43 ).
Malignant Tumors of the Female Urethra
Although carcinoma of the female urethra is more common than that of the male urethra, with a female-to-male symmetry of 4:1, it accounts for less than 0.01% of all malignancies occurring in women. Nigh patients are white and are over 50 age old. Causes associated with the development of urethral cancers in women take chronic nettlesome, urinary tract infection, and proliferative lesions such as caruncles, papillomas, adenomas, polyps, and leukoplakia of the urethra. Approximately 2.5% of patients with urethral caruncle gestate an associated carcinoma. Around patients symbolise with urethral bleeding, urinary frequence, clogging symptoms, and a touchable urethral hatful or induration. Female urethral cancer is classified as either “anterior” urethral cancer or “entire” urethral cancer (37 ). Anterior tumors of the female urethra are set lone in the distal third of the urethra and story for 46% of urethral tumors. At clinical trial, anterior urethral tumour manifests as a masses sticking from the urethral initiative, urethral hemorrhage, dysuria, and urinary oftenness. The anterior urethra below the urogenital diaphragm drains to the little and recondite inguinal nodes, and the backside urethra drains to the impertinent iliac, hypogastric, and obturator nodes; nevertheless, crossing is potentiality. Local functional cut is the intercession of excerpt for anterior urethral lesions. Wax urethral carcinomas tip to be gritty scotch and locally feeler, almost ofttimes with cancroid (60% of patients), followed by transitional booth carcinoma (20%), adenocarcinoma (10%), unvarying tumour and sarcoma (8%), and melanoma (2%). Patients with entire urethral tumors may expect similar symptoms early in the class of the disease but may not face until urinary retention, urethral abscess, or urethrovaginal fistula has developed. Local extension of the lead lesions into the bladder neck, vagina, or vulva is not rarified, and, therefore, specialty of the primary urethral lesions from those of the vulva or vagina may be laborious. For progress entire female urethral lesions, a compounding of or, ray, and, maybe, chemotherapy is requirement.
The diagnosis of urethral tumor in a woman is commonly made at clinical question. Urethrography demonstrates maverick narrowing of the urethra (Fig 27 ). MR imaging has been reported to be exact for evaluating local urethral tumors in 90% of patients. Urethral tumors typically appear hypointense on T1-weighted images and relatively hyperintense on T2-weighted images. Neoplasm extent is outgo evaluated on sagittal T2-weighted images. Tumors in the distal urethra may diversify into the coterminous perineum, and the target-like appearance of the recipe urethra on axial T2-weighted images may be disrupted (44,45 ). CT can demonstrate a urethral hatful with soft-tissue attenuation ( Fig 28 ).
Metastatic Tumors of the Urethra
Junior-grade tumors of the male urethra are rarefied. Bladder transitional cell carcinomas may scattering to the anterior urethra by office of seeding during urethral instrumentation or at cystectomy; these lesions are ordinarily seen as multiple footling mucosal nodules during urethrography (39 ). Prompt bedcover of carcinoma of the prostate, rectum, spermatic cord, and egg may expect the star spongiosum, which causes all-inclusive urethral narrowing and stultification (Fig 29 ). Hematogenous metastases to the corpora cavernosa and star spongiosum are occasionally seen with melanoma and briny prostate, bladder, colonic, testicular, and renal malignancies (39 ). Erosion into the urethra from metastases to the corpus spongiosum may produce urethral irregularities.