Tc-99m pertechnetate is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach.
photon energy: 140 keV
biological half-life: 6 hours
normal distribution: stomach, thyroid, salivary glands, (testicles)
Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. The radioactive technetium radiotracer can be chelated to a number of different compounds to create specific radiopharmaceuticals and optimise the functional imaging of various stru...
Teratomas are germ cell tumours that arise from ectopic pluripotent stem cells that fail to migrate from yolk sac endoderm to the urogenital ridge during embryogenesis. By definition, they contain elements from all three embryological layers: endoderm, mesoderm and ectoderm although frequently, ...
Testicular abscess is usually a complication of severe epididymo-orchitis and needs to be distinguished from other testicular pathology that may present with similar clinical or imaging features.
The majority of patients develop a testicular abscess as a result of untreated or se...
Testicular adrenal rests are a rare cause of a testicular mass.
Testicular adrenal rests can be known by a variety of terms 2:
testicular adrenal rest tumour (TART)
testicular adrenal rest tissue
testicular tumour of the adrenogenital syndrome
testicular adrenal-like tissue
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 ionising radiation.
MRI is occasion...
Testicular and epididymal appendages are remnants of embryonic ducts and are quite common, with one or more being present in ~70% of patients 1.
Four such appendages have been described:
testicular appendix (hydatid of Morgagni)
it is a Müllerian duct remnant (paramesonephric d...
A testicular appendix (alternatively called appendix of testis or appendix testis) represents a developmental remnant of the paramesonephric duct (Müllerian duct) which is situated in the upper pole of the testis inside a groove between the testicle and the head of epididymis 1.
The testicular arteries (also known as the spermatic arteries) are the long, small-diameter gonadal arteries in the male that supply the testis alongside the cremasteric artery and the artery to the ductus deferens.
As paired structures they arise symmetrically, slightly...
Testicular cancers are the most common neoplasm in men between the ages of 20 and 34.
Testicular cancer is uncommon, accounting for less than 1% of all internal organ malignancies 2.
The demographics of affected individuals depends on the age of the histology of the tumour. Over ...
The staging for testicular tumours is performed according to the TNM system with staging groupings. It can be remembered in its abbreviated form as:
stage I: confined to testis, epididymis, spermatic cord, scrotum
stage II: lymph nodes involved but no distant metastases and serum tumour marke...
Simple testicular cysts are usually nonpalpable and thus are detected incidentally.
Testicular cysts require no treatment when discovered.
well-marginated with an imperceptible wall
anechoic with enhanced through transmission
no flow on color Doppler
Testicular epidermoid cysts, also known as keratocysts, are rare benign tumours of germ cell origin that occur in the testis.
Testicular epidermoid cysts account for around 1-2% of all testicular masses and typically present in mid-adulthood (2nd to 4th decades) 1,2. They are the...
Testicular germ cell tumours account for 90% of primary tumours of the testes. They are the most common nonhematologic malignancy in men 15-49 years old.
They are divided into:
testicular seminoma: 40% of germ cell tumours 1
non-seminomatous germ cell tumour: 60% of germ cell tumours
Testicular leukaemia can be seen in patients during and after acute leukaemia. The blood-testis barrier limits chemotherapy from reaching the testicle, and therefore the testicle can act as a harbor for leukaemic cells.
Typically presents with painless testicular enlargem...
Testicular lymphoma is an uncommon cause of testicular malignancy. Lymphoma can involve the testes in three ways:
primary site of extranodal disease (primary testicular lymphoma)
secondary involvement of systemic disease
primary manifestation of subclinical systemic disease
This article is c...
Testicular microlithiasis (TM) is a relatively common condition that represents the deposition of multiple tiny calcifications throughout both testes.
The most common criterion for diagnosis is that of five microcalcifications in one testicle, although definitions have varied in the past. In t...
Testicular mixed germ cell tumours are, as the name suggests, testicular tumours composed of two or more types of germ cell tumour. They are considered to be part of non-seminomatous germ cell tumours, as it is that component which dictates prognosis and treatment.
Overall they account for ove...
Testicular seminomas are the most common testicular tumours and account for ~45% of all primary testicular tumours. This article concerns itself only with testicular seminomas, however, seminomas can arise outside of the testicle most often within the anterior mediastinum, e.g. anterior mediasti...
Testicular teratoma, unlike ovarian teratoma, is often aggressive in its biological behaviour, and often exists as part of testicular mixed germ cell tumours.
Pure testicular teratomas account for only 4-9% of all testicular tumours. A similar number are seen in the context of t...
Testicular torsion occurs when a testicle torts on the spermatic cord resulting in the cutting off of blood supply. The most common symptom is acute testicular pain and the most common underlying cause, a bell-clapper deformity. The diagnosis is often made clinically but if it is in doubt, an ul...
Testicular trauma is the third most-common cause of acute scrotal pain and may result in various degree of damage to the testes.
Testicular rupture and testicular ischaemia/infarct are two severe complications which need to be ruled out. Other injuries that can occur include 1:
Testicular vasculitis can occur as either part of a systemic vasculitis or an isolated vasculitis involving only the testes with both having roughly equal prevalence.
The mean age of onset is approximately 40 years.
Symptoms can include a testicular mass w...
Testicular yolk sac tumours (also known as endodermal sinus tumour of the testis) is the most common childhood testicular tumour (80%), with most cases occurring before the age of two years 1. In adults, pure yolk sac tumour is extremely rare, however mixed germ cell tumour are commonly seen.
The testes (also known as the testicles) are the male gonads and are contained within the scrotum. The testes are responsible for production of sperm and testosterone.
At birth, testes measure approximately 1.5 cm (length) x 1 cm (width), reaching ~4 mL volume at puberty 1.
The threads and streaks sign refers to an angiographic appearance of a vascularised tumour thrombus extending into the ipsilateral renal vein or the inferior vena cava from a renal cell carcinoma. This gives an appearance of linear, thread-like or string-like appearance of the involved vessel.
Throckmorton sign, also known as John Thomas sign, refers to when the penis points in the direction of unilateral disease, typically of the pelvis or hip.
Throckmorton sign is a slang term used humorously by medical students and residents.
According to the first serious study of the sign publ...
Torsion of the appendix testis is the most common cause of an acute painful hemiscrotum in a child. The appendix testis is located at the upper pole of the testis (between the testis and the head of the epididymis).
The normal appendix testis is 1 to 4 mm in length, and it is oval or pedunculat...
Transitional cell carcinoma (TCC) is the most common primary neoplasm of the urinary bladder, and bladder TCC is the most common tumour of the entire urinary system.
This article concerns itself with transitional cell carcinomas of the bladder specifically. Related articles include:
Transitional cell carcinomas of the urothelium are graded histologically as follows:
transitional cell papilloma
benign tumour, not a carcinoma but sometimes included in classification systems
carcinoma in situ
do not penetrate the basement membrane
cells resemble those of grade II or III ...
Transitional cell carcinoma of the bladder staging uses the TNM system which has replaced the previously widely used Jewett-Scott-Marshall tumour staging system. It is very similar to the staging of TCC of the renal pelvis and staging of TCC of the ureter.
Ta - non-invasive papi...
Transitional cell carcinoma of the renal pelvis staging uses the TNM system and is very similar to staging of TCC of the bladder and to staging of TCC of the ureter.
Ta: noninvasive papillary tumour
Tis: in situ (noninvasive flat)
T1: through lamina propria into sub-epithelial...
Transitional cell carcinoma of the ureter staging uses the TNM system and is very similar to staging of TCC of the bladder and to staging of TCC of the renal pelvis.
Ta: noninvasive papillary tumour
Tis: in situ (noninvasive flat)
T1: through lamina propria into sub-epithelia...
Transitional cell carcinoma of the renal pelvis is uncommon compared to renal cell carcinoma and can be challenging to identify on routine imaging when small.
This article concerns itself with TCCs of the renal pelvis specifically. For a general discussion of this tumour please see transitiona...
Staging of transitional cell carcinomas of the urinary tract vary according to the location of the tumour, and are staged using the TNM staging system.
transitional cell carcinoma of the renal pelvis
transitional cell carcinoma of the ureter
transitional cell carcinoma of the bladder
Transitional cell carcinoma of the ureter are uncommon compared to similar tumours elsewhere along the urinary tract but are nonetheless the most common primary tumour of the ureter.
This article concerns itself with transitional cell carcinomas of the ureter specifically. For a general discuss...
Transitional cell carcinoma of the urethra is rare and is limited to the proximal urethra in men (membranous and prostatic). The vast majority of urethral tumours are squamous cell carcinomas.
squamous cell carcinoma of the urethra
transitional cell carcinoma
Transitional cell carcinoma (TCC), also called urothelial cell carcinoma (UCC), is the most common primary malignancy of the urinary tract and may be found along its entire length, from the renal pelvis to the bladder.
As imaging findings and treatment vary according to where along the urinary...
Transjugular renal biopsy can be performed to obtain an adequate tissue sample for histopathologic diagnosis on renal dysfunctions. It is usually performed in high-risk patients in whom percutaneous renal biopsy is not feasible or is contraindicated. This is also useful in morbidly obese patient...
Transplant renal arterial pseudostenosis is uncommon. It is a lesion in the iliac artery proximal to the implantation of the transplant renal artery.
Uncommon, although as the population of renal transplant recipients has become older and more diabetic, the incidence of this disea...
Transrectal ultrasound (TRUS) is a technique that is used most commonly to evaluate
the prostate gland, including ultrasound-guided prostate biopsies
depth of invasion of colon/rectal cancer (for staging purposes)
It can also be used for guidance in placing a transrectal drain, or in rare pro...
Transureteroureterostomy (TUU) is a procedure in which one ureter is divided and then connected (re-routed) into the other. It is performed when a distal ureter needs to be bypassed and can be performed instead of a psoas hitch or Boari flap. It may be preferable if the patient has had prior rad...
Transurethral resection of the prostate (TURP) is a traditional therapy for lower urinary tract symptoms (LUTS) and prostatism from benign prostatic hyperplasia. TURP results in characteristic imaging features.
acute urinary retention
True hermaphroditism is a form of disorder of gender development.
Patients with true hermaphroditism can a mosaic composition of 46XX and 46XY .They therefore have both ovarian and testicular tissues.
There are three forms of true hermaphrotidism
unilateral true hermaph...
Tuberculous adrenalitis is the result of adrenal mycobacterium tuberculosis (TB) infection. Its incidence has decreased in the western world with the declining incidence of tuberculosis.
As the tuberculous infection causes destruction of the adrenal cortex, primary adrenal insufficie...
Tuberous sclerosis (TS), also known as tuberous sclerosis complex or Bourneville disease, is a neurocutaneous disorder (phakomatosis) characterised by the development of multiple benign tumours of the embryonic ectoderm (e.g. skin, eyes, and nervous system).
Tuberous sclerosis has...
The tuberous sclerosis diagnostic criteria have been developed to aid the diagnosis of tuberous sclerosis and have been adapted from Roach et al 1998 1:
definitive TS complex: either 2 major features or 1 major and 2 minor
probable TS complex: 1 major and 1 minor
possible TS complex: either 1...
Tubular ectasia of rete testis represents dilated testicular mediastinal tubules.
This condition is more common in men over the age of 55.
This is a benign condition thought to result from the partial or complete obliteration of the efferent ducts. These spermatozoa-...
Tubular ectasia of the epididymis results in enlargement of the epididymis with multiple cystic interfaces. It typically occurs in those with a prior vasectomy but can be also seen with other causes of obstruction of the ductus deferens.
This can give a charac...
Tumours of the male urethra are uncommon. They can be categorised both on the grounds of histology and location.
squamous cell carcinoma of the urethra: 80%
urothelial/transitional cell carcinoma of the urethra: 15% (predominantly posterior urethra)
adenocarcinoma of the urethra: 5...
Tunica albuginea (TA) cysts are the most common extratesticular benign scrotal mass lesion. They are a type of scrotal tunica cyst.
Their mean age at presentation is 40 years (may be even be seen in the 5th and 6th decades).
They are usually palpable.
Tunica vaginalis cyst is a type of benign paratesticular cystic lesion. This arises in associated to the tunica vaginalis. It is a cyst that arises from the tunica and, in conjunction with tunica albuginea cysts, they are collectively termed scrotal tunica cysts.
Their exact cause is...
Tunica vaginalis testis mesothelioma refers to mesothelioma arising from the tunica vaginalis.
Malignant mesothelioma originating from the tunica vaginalis is extremely rare.
Patients usually present with enlarging or recurrent hydrocele, or less frequen...
An umbilical-urachal sinus belongs to the spectrum of congenital urachal anomalies and represents a non-communicating dilatation of the urachus at the umbilical end.
Presentation is commoner in children and rare in adult.
An umbilical-urachal sinus...
Urachal cysts are one of the manifestations of the spectrum of congenital urachal remnant abnormalities.
Urachal cysts usually remain asymptomatic until complicated by infection or bleeding.
Infected urachal cyst can occur at any age.
The urachus is the fibrous vestigal remnant of the fetal allantois.
The lumen of the urachus usually obliterates after birth and it becomes the median umbilical ligament, a midline linear fibrous fold of parietal peritoneum, extending from the apex of the bladder to the umbilicus.
If the lumen...
The ureter is a paired fibromuscular tube that conveys urine from the kidneys in the abdomen to the bladder in the pelvis.
The ureter is 25-30 cm long and has three parts:
abdominal ureter: from the renal pelvis to the pelvic brim
pelvic ureter: from the pelvic brim to the bla...
Ureteral duplication is the most common congenital abnormality associated with the urinary tract, and occurs in ~1% of the population.
Duplication can occur unilaterally or bilaterally, and may be partial or complete:
partially duplicated ureters fuse into a single ureter proxim...
Ureteral pseudodiverticulosis is acquired false diverticula resulting from herniation of epithelium through the muscularis layer of the ureter and characterized by the presence of multiple outpouchings smaller than 5 mm. It is more commonly bilateral and located in the upper two-thirds of the ur...
A number of tumours may affect the ureter, by far the most common histology being transitional cell carcinoma.
transitional cell carcinoma of the ureter: 95% 1
squamous cell carcinoma of the ureter: 5%
adenocarcinoma of the ureter: <1%
The ureteric bud (also known as the metanephrogenic diverticulum) is a protrusion of the mesonephric duct that appears during the embryological development of urogenital organs. It will eventually form the urinary collecting system (i.e. collecting tubes, calyces, renal pelvis, ureter) of the ki...
Ureteric calculi or stones are those lying within the ureter, at any point from the ureteropelvic junction (UPJ) to the ureterovesical junction (UVJ). They are the classic cause of renal colic-type abdominal pain. They are a subset of the broader topic of urolithiasis.
Ureteric injury is a relatively uncommon, but severe event, which may result in serious complications as a diagnosis is often delayed.
Ureteric injuries unreliably demonstrate macro- or micro-scopic haematuria as it may be absent in up to 25% of patients 5, 6. Classic cl...
Ureteric rupture is rare but has been described. It may be spontaneous or secondary to another pathology or intervention.
The most common symptoms are sudden, severe, persistent lower abdominal pain with severe peritoneal irritation. Abdominal compartment syndrome, respir...
Ureteric stents, also known as double J stents or retrograde ureteric stents, is a urological catheter that has two "J-shaped" (curled) ends, where one is anchored in the renal pelvis and the other inside the bladder.
Stents are used for the free passage of urine from the kidney to the bladder,...
Ureteritis refers to inflammation of the ureter, it is rare and is often associated with cystitis or pyelonephritis 1.
Patients may present with symptoms of cystitis or pyelonephritis with suprapubic/flank pain, dysuria, haematuria and/or fever. White cell count may also...
Ureteritis cystica or pyeloureteritis cystica is a benign condition of the ureters representing multiple small submucosal cysts.
Typically this condition is seen in diabetics, with recurrent urinary tract infection. As such is is most frequently seen in older patients and is more...
Ureterocoeles represent congenital dilatation of the distal-most portion of the ureter. The dilated portion of the ureter may herniate into the bladder secondary to the abnormal structure of vesicoureteric junction (VUJ).
Most ureterocoeles are congenital, usually associated with ...
Ureterovaginal fistulae refer to abnormal communications between the lumina of the ureter(s) and the vagina.
Patients usually present with urinary incontinence through the vagina which may be accompanied by fever and chills 1. Symptoms usually begin within 2-4 weeks foll...
The urethra is the terminal segment of the genitourinary system. Because of vastly different anatomy between the sexes, male and female urethras are discussed separately:
Urethral agenesis (or urethral atresia) refers to a situation where there is a congenital absence of the urethra. It can be a cause of fetal obstructive uropathy.
prune belly syndrome 5
bladder agenesis 2
May show a dilate...
Urethral calculi are an uncommon type of urolithiasis, accounting for ~1% of all urinary tract stones.
They almost all occur in males 2 with two peak incidences - one in childhood and the other at 40 years 3.
Most commonly acute lower urinary tract symptoms...
Various radiological and surgical instruments, including urethral clamps, have been developed to try to improve retrograde/ascending urethrogram (RUG/ASU) and voiding cystourethrogram (VCUG) technique in males. These are very rarely (if ever) used anymore.
This device has a metall...
Urethral diverticulum, or urethrocoele, is a focal outpouching of the urethra. It should not be confused with a ureterocoele of the distal ureter.
Urethral diverticula occur far more frequently in women than in men and are estimated to occur in 1-6% of women, especially those with...
Urethral diverticulum adenocarcinoma is a rare occurrence in a urethral diverticulum.
Urethral diverticulum seen in ~0.6-6% of women. In small series, only 3-6% of resected urethral diverticula show adenocarcinoma 3-4.
Urinary frequency, urgency, burning mictur...
Urethral duplication is a rare condition in which either a part or the entire urethra is duplicated. It usually occurs in the sagittal plane and the more dorsal copy is usually the duplication.
A urethral duplication may occur due to a variety of developmental miscues. In a woman, it...
Urethral injuries can result in long-term morbidity and most commonly result from trauma. The male urethra is much more commonly injured than the female urethra and is the focus of this article.
In the setting of trauma, the classic triad of blood of the external urethral...
Urethral strictures are relatively common and typically occur either in the setting of trauma or infection.
The demographics of the affected population is dictated by the aetiology, but in general, it is safe to say that adult males make up the vast majority of cases.
Urethrography refers to the radiographic study of the urethra using iodinated contrast media and is generally carried out in males.
When the urethra is studied with instillation of contrast into the distal/anterior urethra it has been referred to as
retrograde urethrography (RUG)...
The urinary bladder (more commonly just called the bladder) is a distal part of the urinary tract and is an extra-peritoneal structure located in the true pelvis.
The bladder has a triangular shape with a posterior base, an anterior apex and an inferior neck with two inferolatera...
There are numerous causes of urinary bladder diverticula:
Primary (congenital or idiopathic)
Hutch diverticulum (in paraureteral region)
Bladder outlet obstruction
bladder neck stenosis
posterior urethral valve
prostatic enlargement (hypertrophy; carcinoma)
Bladder diverticulum are outpouchings from the bladder wall, whereby mucosa herniates through the bladder wall. They may be solitary or multiple in nature and can vary considerably in size.
There are two peaks - one at 10 years and the other at 60-70 years 2.
Herniation of the urinary bladder is a relatively uncommon but not a rare condition. It occurs when the urinary bladder or ureter herniates into the inguinal canal, scrotal sac or femoral canal. Herniations through ischiorectal, obturator or abdominal wall openings have also been described. Blad...
Urinary bladder rupture is usually seen in the context of significant trauma.
Bladder rupture can be categorised into five types depending on the location and extent of the rupture.
This is commonly seen but sometimes not classed as true rupture, since...
Causes of urinary bladder wall or lumen calcification include:
schistosomiasis of the urinary tract
calculus in a urachal cyst or in a bladder divertic...
Urinary diversion is created after the removal of the urinary bladder (radical cystectomy or cystoprostatectomy, usually done to treat invasive bladder cancer).
There are three main varieties:
neobladder formed from a segment of ileum (i.e. ileal conduit, also known as a "Bricker conduit")
The urinary system consists of the kidneys, ureter, bladder and urethra. With the exception of the urethra, this is equitable in both males and females. It spans the abdomen and pelvis, from the upper abdomen to the extreme pelvis, being inextricably linked with the genital system.
Urinary tract infection (UTI) is a common clinical condition involving the bladder (cystitis) and kidneys (pyelonephritis). It is commonly divided into 'uncomplicated' and 'complicated' infections.
UTIs occur when there is bacterial colonisation of the uroepithelium and a subsequent...
Urinomas, or uriniferous fluid collections, are urine collections usually found in the retroperitoneum, most commonly in the perirenal space, as a consequence of renal track leakage caused by urinary obstruction, trauma, or post-instrumentation.
Although there is no definitive dis...
Urinothorax is a rare cause of pleural effusion due to the accumulation of urine within the pleural space.
Patients present with varying degrees of respiratory distress depending on the amount of fluid that has accumulated 1,3.
The aetiology of urinothorax can...
The urogenital curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core genitourinary knowledge.
Topics pertaining to the urinary tract (kidneys, ureter, bladder, urethra), adrenal glands, prostate penis, scrotal content (testes, ...
The urogenital triangle forms the anterior half of the diamond-shaped perineum. The triangle's corners are defined by the pubis symphysis anteriorly and the ischial tuberosities anterolaterally. The anterolateral borders are the ischiopubic rami and the posterior border is the transverse perinea...
Urolithiasis refers to the presence of calculi anywhere along the course of the urinary tracts. For the purpose of the article, the terms urolithiasis, nephrolithiasis and renal/kidney stones are used interchangeably, although some authors have slightly varying definitions of each.
See main ar...