Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

733 results found
Article

Transitional cell carcinoma of the bladder (staging)

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. TNM staging T Ta - non-invasive papi...
Article

Transitional cell carcinoma of the renal pelvis (staging)

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. TNM staging T Ta: noninvasive papillary tumour Tis: in situ (noninvasive flat) T1: through lamina propria into sub-epithelial...
Article

Transitional cell carcinoma of the ureter (staging)

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.  TNM staging T Ta: noninvasive papillary tumour Tis: in situ (noninvasive flat) T1: through lamina propria into sub-epithelia...
Article

Transjugular renal biopsy

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...
Article

Transplant renal arterial pseudostenosis

Transplant renal arterial pseudostenosis is uncommon. It is a lesion in the iliac artery proximal to the implantation of the transplant renal artery. Epidemiology Uncommon, although as the population of renal transplant recipients has become older and more diabetic, the incidence of this di...
Article

Transrectal ultrasound

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...
Article

Transureteroureterostomy

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...
Article

Transurethral resection of the prostate

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. Indications acute urinary retention recurrent infection recurrent haematuria azo...
Article

True hermaphroditism

True hermaphroditism is a form of disorder of gender development.  Pathology Patients with true hermaphroditism can a mosaic composition of 46XX and 46XY .They therefore have both ovarian and testicular tissues. Sub types There are three forms of true hermaphrotidism unilateral true hermaph...
Article

Tuberculous adrenalitis

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. Pathology As the tuberculous infection causes destruction of the adrenal cortex, primary adrenal insufficie...
Article

Tuberous sclerosis

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). Epidemiology Tuberous sclerosis has...
Article

Tuberous sclerosis diagnostic criteria

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...
Article

Tubular ectasia of rete testis

Tubular ectasia of rete testis represents dilated testicular mediastinal tubules.  Epidemiology This condition is more common in men over the age of 55.  Pathology This is a benign condition thought to result from the partial or complete obliteration of the efferent ducts. It is often bilate...
Article

Tubular ectasia of the epididymis

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. Radiographic features Ultrasound This can give a charac...
Article

Tumour thrombus

Tumour thrombus is defined as tumour demonstrated within a vessel, typically a vein.  This phenomenon is classically associated renal cell carcinoma (RCC), where tumour may invade the renal vein and migrating proximally where it can reach the right atrium. Tumour thrombus is usually composed of ...
Article

Tumours of the male urethra

Tumours of the male urethra are uncommon. They can be categorised both on the grounds of histology and location. Histology squamous cell carcinoma of the urethra: 80% urothelial/transitional cell carcinoma of the urethra: 15% (predominantly posterior urethra) adenocarcinoma of the urethra: 5...
Article

Tunica albuginea cyst

Tunica albuginea (TA) cysts are the most common extratesticular benign scrotal mass lesion. They are a type of scrotal tunica cyst. Epidemiology Their mean age at presentation is 40 years (may be even be seen in the 5th and 6th decades). Clinical presentation They are usually palpable. Path...
Article

Tunica vaginalis cyst

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. Pathology Their exact cause is...
Article

Tunica vaginalis testis mesothelioma

Tunica vaginalis testis mesothelioma refers to mesothelioma arising from the tunica vaginalis.  Epidemiology Malignant mesothelioma originating from the tunica vaginalis is extremely rare.  Clinical presentation  Patients usually present with enlarging or recurrent hydrocele, or less frequen...
Article

Umbilical-urachal sinus

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. Clinical presentation Presentation is commoner in children and rare in adult. Radiographic features An umbilical-urachal sinus...
Article

Urachal cyst

Urachal cysts are one of the manifestations of the spectrum of congenital urachal remnant abnormalities.  Clinical presentation Urachal cysts usually remain asymptomatic until complicated by infection or bleeding. Epidemiology Infected urachal cyst can occur at any age. Pathology Urachal c...
Article

Urachus

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...
Article

Ureter

The ureter is a paired fibromuscular tube that conveys urine from the kidneys in the abdomen to the bladder in the pelvis.  Gross anatomy 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...
Article

Ureteral duplication

Ureteral duplication is the most common congenital abnormality associated with the urinary tract, and occurs in ~1% of the population. Gross anatomy Duplication can occur unilaterally or bilaterally, and may be partial or complete: partially duplicated ureters fuse into a single ureter proxim...
Article

Ureteral pseudodiverticulosis

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...
Article

Ureteral tumours

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%
Article

Ureteric bud

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...
Article

Ureteric calculi

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. Epidemiology The lifetim...
Article

Ureteric injury

Ureteric injury is a relatively uncommon, but severe event, which may result in serious complications as a diagnosis is often delayed.  Clinical presentation Ureteric injuries unreliably demonstrate macro- or micro-scopic haematuria as it may be absent in up to 25% of patients 5, 6. Classic cl...
Article

Ureteric rupture

Ureteric rupture is rare but has been described. It may be spontaneous or secondary to another pathology or intervention. Clinical presentation The most common symptoms are sudden, severe, persistent lower abdominal pain with severe peritoneal irritation. Abdominal compartment syndrome, respir...
Article

Ureteric stent

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,...
Article

Ureteritis

Ureteritis refers to inflammation of the ureter, it is rare and is often associated with cystitis or pyelonephritis 1.  Clinical presentation Patients may present with symptoms of cystitis or pyelonephritis with suprapubic/flank pain, dysuria, haematuria and/or fever. White cell count may also...
Article

Ureteritis cystica

Ureteritis cystica or pyeloureteritis cystica is a benign condition of the ureters representing multiple small submucosal cysts.  Epidemiology 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...
Article

Ureterocoele

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). Epidemiology Most ureterocoeles are congenital, usually associated with ...
Article

Ureterovaginal fistula

Ureterovaginal fistulae refer to abnormal communications between the lumina of the ureter(s) and the vagina.  Clinical presentation 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...
Article

Urethra

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: female urethra male urethra
Article

Urethral agenesis

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. Pathology Associations prune belly syndrome 5 bladder agenesis 2 Radiographic features Antenatal ultrasound May show a dilate...
Article

Urethral calculus

Urethral calculi are an uncommon type of urolithiasis, accounting for ~1% of all urinary tract stones. Epidemiology They almost all occur in males 2 with two peak incidences - one in childhood and the other at 40 years 3. Clinical presentation Most commonly acute lower urinary tract symptoms...
Article

Urethral clamps

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. Brodny clamp This device has a metall...
Article

Urethral diverticulum

Urethral diverticulum, or urethrocoele, is a focal outpouching of the urethra. It should not be confused with a ureterocoele of the distal ureter. Epidemiology Urethral diverticula occur far more frequently in women than in men and are estimated to occur in 1-6% of women, especially those with...
Article

Urethral diverticulum adenocarcinoma

Urethral diverticulum adenocarcinoma is a rare occurrence in a urethral diverticulum. Epidemiology Urethral diverticulum seen in ~0.6-6% of women. In small series, only 3-6% of resected urethral diverticula show adenocarcinoma 3-4. Clinical features Urinary frequency, urgency, burning mictur...
Article

Urethral duplication

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. Pathology A urethral duplication may occur due to a variety of developmental miscues. In a woman, it...
Article

Urethral injury

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. Clinical presentation In the setting of trauma, the classic triad of blood of the external urethral...
Article

Urethral stricture

Urethral strictures are relatively common, and typically occur either in the setting of trauma or infection. Epidemiology 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. Clinical pr...
Article

Urethrography

Urethrography refers to the radiographic study of the urethra using iodinated contrast media and is generally carried out in males.  Terminology When the urethra is studied with instillation of contrast into the distal/anterior urethra it has been referred to as retrograde urethrography (RUG)...
Article

Urinary bladder

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. Gross anatomy The bladder has a triangular shape with a posterior base, an anterior apex and an inferior neck with two inferolatera...
Article

Urinary bladder diverticula (causes)

There are numerous causes of Urinary bladder diverticula:  Primary (congenital or idiopathic) Hutch diverticulum (in paraureteral region) Secondary Bladder outlet obstruction bladder neck stenosis neurogenic bladder posterior urethral valve prostatic enlargement (hypertrophy; carcinoma) ...
Article

Urinary bladder diverticulum

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. Epidemiology There are two peaks - one at 10 years and the other at 60-70 years 2. Pathology Diverticu...
Article

Urinary bladder hernia

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...
Article

Urinary bladder rupture

Urinary bladder rupture is usually seen in the context of significant trauma. Classification Bladder rupture can be categorised into five types depending on the location and extent of the rupture.  Bladder contusion This is commonly seen but sometimes not classed as true rupture, since it in...
Article

Urinary bladder wall or lumen calcification (differential)

Causes of urinary bladder wall or lumen calcification include: Common bladder calculus schistosomiasis of the urinary tract tuberculosis Uncommon neuroblastoma; pheochromocytoma radiation reaction alkaptonuria (ochronosis) amyloidosis calculus in a urachal cyst or in a bladder divertic...
Article

Urinary diversion

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") th...
Article

Urinary system

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. The urinary...
Article

Urinary tract infection

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.  Pathology UTIs occur when there is bacterial colonisation of the uroepithelium and a subsequent...
Article

Urinoma

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.  Terminology Although there is no definitive dis...
Article

Urogenital curriculum

The urogenital curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core genitourinary knowledge. Definition  Topics pertaining to the urinary tract (kidneys, ureter, bladder, urethra), adrenal glands, prostate penis, scrotal content (testes, ...
Article

Urolithiasis

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 or kidney stones are used interchangeably, although some authors have slightly varying definitions of each.  See main...
Article

US abdomen (summary)

Ultrasound abdomen is one of the tests that is commonly used in the assessment of patients with abdominal pain. It is particularly useful for the assessment of solid organs and fluid-filled structures. Reference article This is a summary article; we do not have a more in-depth reference articl...
Article

Vaginal artery

The vaginal artery is a branch of the anterior division of the internal iliac artery, and should not to be mistaken with the vaginal branch of the uterine artery. It is often considered to be a homolog of the inferior vesical artery, which is present only in males. Summary origin: anterior div...
Article

Varicocele (grading on colour Doppler)

Varicocele grading can be done variably. The most elaborate and accepted grading was given by Sarteschi, which is briefed below.  For a general discussion of this condition refer to the article: varicocele. Evaluation first do a baseline grey scale study in supine position and measure the dia...
Article

Varicocoele

Varicocoele is the dilatation of pampiniform plexus of veins, a network of many small veins found in the male spermatic cord. It is the most frequently encountered mass of the spermatic cord. Epidemiology The estimated incidence is at ~15% of general male population and ~40% of subfertile and ...
Article

Varicocoele embolisation

Varicocoele embolisation is a minimally invasive method of treating varicoceles by embolising the testicular vein (internal spermatic veins). Indications symptomatic varicocoele infertility/subfertility failed surgical ligation Contraindications Relative contraindications include: intrave...
Article

Vasitis

Vasitis is an uncommon inflammatory disorder of the vas deferens and spermatic cord. It is classified as either the generally asymptomatic vasitis nodosa (seen after vasectomy) or acutely painful infectious vasitis 1. This article refers to the acute infective form as imaging is generally not un...
Article

Vesico-urachal diverticulum

Vesico-urachal diverticulum is one of the congenital urachal remnant abnormalities. Gross anatomy It is the proximal equivalent of a urachal umbilical sinus, representing a result of the failure of the urachus to close at the urinary bladder, forming an out-pouching of variable length from the...
Article

Vesico-vaginal fistula

Vesico-vaginal fistulas are abnormal fistulous connections between the urinary bladder and vagina, resulting in an involuntary discharge of urine through the vagina. Epidemiology The overall incidence of vesicovaginal fistula is unknown but was reported to be 2.11 per 100 births in Nigeria 1. ...
Article

Vesicoureteric reflux

Vesicoureteric reflux (VUR) is the term for abnormal flow of urine from the bladder into the upper urinary tract and is typically a problem encountered in young children.  For grading of vesicoureteric reflux, please refer to vesicoureteric reflux grading. Epidemiology The incidence of UTI is...
Article

Vesicoureteric reflux (grading)

Vesicoureteric reflux (VUR) grading divides vesicoureteric reflux according to the height of reflux up the ureters and degree of dilatation of the ureters: grade 1: reflux limited to the ureter grade 2: reflux up to the renal pelvis grade 3: mild dilatation of ureter and pelvicalyceal system ...
Article

Vesicovaginal reflux

Vesicovaginal reflux is a well-known entity rarely encountered by radiologists. It is a behavioural disorder, a type of dysfunctional elimination syndrome commonly encountered in pre-pubertal girls. It is defined as reflux of urine into the vaginal vault either in supine or upright position duri...
Article

Vicarious contrast material excretion

Vicarious contrast material excretion (VCME) defines excretion of water-soluble contrast material in a way other than via normal renal secretion.  The most common vicarious excretion of water-soluble contrast material is via the liver, resulting in increased bile density seen in the gallbladder...
Article

Voiding cystourethrography

Voiding cystourethrography (VCUG), also known as a micturating cystourethrography (MCU),  is a fluoroscopic study of the lower urinary tract in which contrast is introduced into the bladder via a catheter. The purpose of the examination is to assess the bladder, urethra, postoperative anatomy an...
Article

Von Hippel-Lindau disease

Von Hippel-Lindau (vHL) disease is characterised by the development of numerous benign and malignant tumours in different organs (at least 40 types 1) due to mutations in the VHL tumour suppressor gene on chromosome 3. Epidemiology The disease is rare with an estimated prevalence of 1:35,000-5...
Article

Waterhouse-Friderichsen syndrome

Waterhouse-Friderichsen syndrome is characterised by adrenal insufficiency that results from atraumatic adrenal haemorrhage in consequence of septicaemia.  Pathology Waterhouse-Friderichsen syndrome is due to septicaemia and common infective agents include 5: meningococcus: traditionally desc...
Article

Weigert-Meyer law

The Weigert-Meyer law describes the relationship of the upper and lower renal moieties in duplicated collecting systems to their drainage inferiorly. Weigert-Meyer law With duplex kidney and complete ureteral duplication, the upper renal and lower renal moiety have their own ureters with each ...
Article

White pyramid sign (kidney)

The white pyramid sign refers to the CT appearance of the medullary pyramids of the kidney which can be seen normally on unenhanced CT scans as high-attenuation triangular structures.  Bilateral high-attenuation renal pyramids are an occasional incidental normal finding.  In contrast, unilatera...
Article

WHO histological classification of benign renal neoplasms

Benign renal tumours were histologically classified according to the WHO in 2004 as follows 1: Renal cell tumours renal oncocytoma renal papillary adenoma - renal adenoma Metanephric tumours metanephric adenoma of kidney metanephric adenofibroma of kidney metanephric stromal tumour of kid...
Article

Wilms tumour

Wilms tumour, also known as nephroblastoma, is a malignant paediatric renal tumour. Epidemiology Wilms tumours are the most common paediatic renal mass, accounting for over 85% of cases 1,8 and accounts for 6% of all childhood cancers 2. It typically occurs in early childhood (1-11 years) with...
Article

Wilms tumour (staging)

Wilms' tumour staging is largely anatomical and relates to the invasion and spread of the tumour. Where there is invasion or metastasises, prognosis is poorer. Wilms tumour, is one of the more common childhood malignancies. stage I confined to kidney complete resection possible stage II loc...
Article

Wolffian duct

The Wolffian duct (also known as the mesonephric duct) is one of the paired embryogenic tubules that drain the primitive kidney (mesonephros) to the cloaca. In both the male and the female the Wolffian duct develops into the trigone of the urinary bladder. Development Female In the female, in...
Article

Wunderlich syndrome

Wunderlich syndrome is a rare condition, in which spontaneous nontraumatic renal haemorrhage occurs into the subcapsular and perirenal spaces 2. Clinical features Wunderlich syndrome is clinically characterized by Lenk's triad acute flank pain flank mass hypovolaemic shock Pathology Aetio...
Article

Xanthogranulomatous pyelonephritis

Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis and represents a chronic granulomatous disease resulting in a non-functioning kidney. Radiographic features are usually specific. Epidemiology Xanthogranulomatous pyelonephritis is seen essentially in all age gro...
Article

Young syndrome

Young syndrome shares similar clinical and radiological findings to primary ciliary dyskinesia and cystic fibrosis, however the underlying pathogenesis yet to be fully elucidated. Obstructive azoopsermia at the level of the epididymis is thought to be the cause of infertility. The commonly refer...
Article

Zinner syndrome

Zinner syndrome is a triad of Wolffian duct anomalies that includes unilateral renal agenesis, ipsilateral seminal vesicle cyst, and ejaculatory duct obstruction 1. Clinical presentation Patients are typically diagnosed at 3rd or 4th decade of life and often present with perineal pain, recurre...

Updating… Please wait.
Loadinganimation

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.