Hypospadias refers to a type of congenital malformation affecting the male external genitalia.
The estimated prevalence is ~2 (range 0.2-4.1) per 1000 live births.
The urethral meatus is abnormally positioned proximally and ventrally to its normal position.
It is thou...
Hydrocoele of the canal of Nuck is a rare condition in female children caused by a failure of complete obliteration of the canal of Nuck 1. The canal of Nuck is an abnormal patent pouch of peritoneum extending anterior to the round ligament of the uterus into the labia majora 2. Incomplete oblit...
Hydrocoeles are acquired or congenital serous fluid collection between the layers of the tunica vaginalis surrounding a testis or spermatic cord. They are the most common form of testicular enlargement and present with painless enlargement of the scrotum. On all modalities, hydrocoeles appear as...
Hutch diverticula are congenital bladder diverticula, seen at the vesicoureteric junction, in the absence of posterior urethral valves or neurogenic bladder. They are thought to result from a weakness in the detrusor muscle anterolateral to the ureteral orifice.
They occur almost...
A horseshoe adrenal gland is a very rare anomaly. It is also sometimes called a butterfly adrenal gland, fused adrenal gland or midline adrenal gland.
It is a solitary adrenal gland that is present in the midline of the fused portion either passing between the aorta and the inferior vena cava o...
HIV-associated nephropathy (HIVAN) is commonly seen in patients with HIV/AIDS and leads to end-stage renal disease (ESRD). The diagnosis is not imaging-based and must be confirmed by renal biopsy.
HIVAN is seen in patients at advanced stages of HIV and AIDS, but it can also be see...
Herlyn-Werner-Wunderlich (HWW) syndrome, is a rare anomaly characterised by Müllerian duct anomalies (MDA) associated with mesonephric duct anomalies 3. This entity is also known as obstructed hemivagina and ipsilateral renal anomaly (OHVIRA). It is not to be confused with the Wunderlich syndro...
Despite the vast majority of renal cancers being sporadic, there are a number of hereditary renal cancer syndromes:
von Hippel Lindau syndrome: predominantly clear cell type
tuberous sclerosis: predominantly clear cell type
hereditary leiomyomata renal cell cancer syndrome: described in ISUP ...
Hereditary breast and ovarian cancer (HBOC) syndrome is caused by a mutation to either BRCA1 or BRCA2 genes. These patients have an increased risk of breast cancer, ovarian cancer, pancreatic cancer and prostate cancer. However, these gene mutations are not the only cause of hereditary breast ca...
The haemorrhage exclusion sign can be a useful MRI finding following prostate biopsy.
The normal prostate produces high concentrations of citrate, which among other properties, acts as an anticoagulant 1. As tumour cells are dysfunctional, they will produce lower levels of citrate th...
Haemolytic uraemic syndrome (HUS) is a multisystem thrombotic microangiopathic disease characterised by the triad of renal failure, haemolytic anaemia and thrombocytopenia. It is the most common cause of renal failure in infancy and childhood requiring dialysis.
There are two forms of this syn...
Haematuria in a child is evaluated differently than in an adult in two main respects:
there is a lower likelihood of a malignancy (renal or bladder) causing the haematuria
preference is given to nonionizing radiation
Haematuria can be considered in three main forms:
Haematospermia refers to the presence of blood in semen or ejaculatory fluid. It is a symptom that can cause great anxiety in patients despite commonly being of benign aetiology.
urogenital infections including sexually transmitted disease
commonest cause in patients <40 ...
Haematuria occurs when blood enters the urinary collecting system. There are many aetiologies for haematuria, and they range from benign and transient to gravely concerning. Haematuria can derive from the kidneys, ureters, bladder, prostate (in men), or urethra. Imaging can often be useful to de...
Eosinophilic ureteritis (and eosinophilic pyelouerteritis) is a rare cause of ureteral inflammation. The clinical presentation and imaging features are nonspecific.
Patients are usually atopic or hypereosinophilic with peripheral eosinophilia.
Associated with eosinophili...
Emphysematous cystitis (EC) refers to gas forming infection of the bladder wall.
The condition is rare and usually confined to certain patient subgroups.
Risk factors include:
considered the commonest predisposing factor 6
may be present in ~50%...
Epispadias is a rare congenital anomaly that is almost always associated with bladder exstrophy.
It occurs in 1 in 30,000 births, with a male: female ratio of 3:1.
The roof of the urethra is absent and the urethra opens anywhere between the base and the gl...
The epididymis (plural epididymides) is situated adjacent to the testis within the scrotal sac. Its primary function is the collection, maturation and transport of sperm via the ductus deferens.
The epididymis is an elongated structure, posterolateral to the testis. It can divide...
Epididymal masses are most commonly encountered on ultrasonography. Most epididymal masses are benign; malignant lesions are rare.
adenomatoid tumour of the scrotum (most common epididymal mass 4)
sperm granulomas / post vasectomy gra...
Epididymal cysts are the most common epididymal mass.
Epididymal cysts have been reported in ~30% (range 20-40%) of asymptomatic individuals 5.
They are usually of lymphatic origin 2. The cysts contain clear serous fluid, lymphocytes, spermatozoa and debris.
Epididymal calcification can be seen on ultrasound as hyperechoic foci within the epididymal head. If the calcifications are large enough, then they may demonstrate acoustic shadowing.
chronic epididymitis: e.g. bacterial, granulomatous (TB) or genital filariasis
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...
Folliculin gene-associated syndrome (FLCN-S) or Birt-Hogg-Dubé (BHD) syndrome is a genetic multisystemic disease mainly characterised by:
multiple lung cysts and secondary spontaneous pneumothoraces
multiple bilateral renal tumours (particularly chromophobe renal cell cancer and oncocytoma)
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 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.
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...
Diabetes insipidus (DI) is the deficiency or resistance to the hormone vasopressin (antidiuretic hormone), which results in polyuria and polydipsia.
DI occurs in 3 per 100,000 people 2.
DI may be described as 1-3:
central/neurogenic/hypothalamic: vasopressin deficie...
There are several peri-urethral cystic lesions. These include:
female genitourinary tract:
Gartner duct cyst
epidermal inclusion cyst of the vagina
Skene duct cyst
Bartholin gland cyst
endometrial cyst of perineal - vulval - vaginal region
Vesico-vaginal fistulas are abnormal fistulous connections between the urinary bladder and vagina, resulting in an involuntary discharge of urine through the vagina.
The overall incidence of vesicovaginal fistula is unknown but was reported to be 2.11 per 100 births in Nigeria 1.
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...
Wilms tumour, also known as nephroblastoma, is a malignant paediatric renal tumour.
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...
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.
Xanthogranulomatous pyelonephritis is seen essentially in all age gro...
Cryptorchidism refers to an absence of a testis (or testes) in the scrotal sac. It may refer to an undescended testis, ectopic testis, or an atrophic or absent testis. Correct localisation of the testes is essential because surgical management varies on location.
The testes develop i...
Crossed fused renal ectopia essentially refers to an anomaly where the kidneys are fused and located on the same side of the midline.
The estimated incidence is around 1 out of 1000 births 1. There is a recognised male predilection with a 2:1 male to female ratio. More than 90% of...
Congenital urachal anomalies are a spectrum of potential anomalies that can occur due to incomplete involution of the urachus.
A urachal remnant occurs in approximately 1 in 5000 patients.
The urachus connects the dome of the bladder to the umbilical cord during fetal ...
Colovesical fistulas are communications between the lumen of the colon and that of the bladder, either directly or via an intervening abscess cavity (foyer intermediaire). When the communication is between the rectum and urinary bladder, the term rectovesical fistula is used.
Chronic pyelonephritis is a form of pyelonephritis where there are longstanding sequelae of renal infection. At the time of writing there is still no definitive consensus as to whether the condition represents an active chronic infection, arises from multiple recurrent infections, or represents ...
Clear cell sarcomas of the kidney are a rare mesenchymal renal tumour that account for ~5% of primary renal neoplasms in the paediatric population 1.
CCS is the second most common primary malignant renal neoplasm after Wilms tumour, with an annual incidence of 20 cases in the Uni...
Chronic kidney disease (CKD), also known as chronic renal failure, is a progressive loss of glomerular function caused by a long-standing renal parenchymal disease. It is present when the glomerular filtration rate (GFR) is less than 60 ml/min/1.73 m2 for three consecutive months or greater than...
Chronic periaortitis is an inflammatory condition which typically involves the infrarenal portion of the abdominal aorta. It is a rare disease usually occurring in middle-aged men.
It has various clinical presentations:
idiopathic retroperitoneal fibrosis (IRF)
perianeurysmal retroperitoneal ...
Varicocoele is the dilatation of the 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.
The estimated incidence is at ~15% of general male population and ~40% of subfertile ...
Cesarean section scar diverticulums are a defect in the lower uterine cavity at the site of the cesarean section scar.
in a study was found to be the only finding in patients with bleeding disturbances
Calyceal microlithiasis or more specifically renal calyceal microlithiasis is defined as <3 mm hyperechoic foci noted within the renal calyces on gray scale ultrasonography 1. It has been considered as a precursor for renal stone formation.
The patient may be asymptomati...
Calciphylaxis, or calcific ureamic arteriolopathy, is a rare condition which manifests as subcutaneous vascular calcification and cutaneous necrosis (small blood vessels of the fat tissue and the skin). Some authors describe as a syndrome of vascular calcification, thrombosis and skin necrosis.
A burned out testis tumour may be present if there is metastatic retroperitoneal lymphadenopathy, but the primary testicular tumor is a relatively occult, scarred intratesticular focus. Approximately 50% of the "burned out" tumors continue to harbor malignant cells.
Bullet and bodkin sign is the appearance of the ureter when there is an abrupt transition in the ureteral caliber. Bullet in the name is represented by the dilated proximal ureteric segment which appears to be perched on the constricted / non-dilated encased ureter which gives an appearance of a...
Bladder exstrophy (also known as ectopia vesicae) refers to a herniation of the urinary bladder through an anterior abdominal wall defect. The severity of these defects is widely variable.
The estimated incidence of bladder exstrophy is 1:10,000-50,000 live births 4,6. There is a ...
Bladder and ureteric tuberculosis (TB) refers to infection of ureters and urinary bladder with Mycobacterium tuberculosis.
characteristic beaded appearance due to alternate areas of strictures and dilatation (chronic state)
acute: ureteral wall thic...
Behçet disease is a multi-systemic and chronic inflammatory vasculitis of unknown aetiology.
The mean age at which Behçet disease occurs is 20-30 years. The disease is most prevalent in the Mediterranean region, Middle East and East Asia. The highest incidence has been reported in...
Azoospermia refers to complete absence of sperm in the semen. It accounts for 5-10% of male infertility 1.
It can be obstructive or non-obstructive, e.g. primary testicular failure. This differentiation is of utmost importance, as obstructive azoospermia can be corrected by surgical ...
Autosomal dominant polycystic kidney disease (ADPKD), also sometimes more vaguely referred to as "adult polycystic kidney disease", is as the name would suggest, a hereditary form of adult cystic renal disease.
Autosomal dominant polycystic kidney disease is one of the most commo...
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...
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.
The spaghetti sign refers to the presence of a linear worm like filling defect within a contrast opacified bladder. This linear filling defect is considered to represent blood clot extruded from the ureter and thereby moulded in the tubular shape. It is seen in patients with gross haematuria. Pr...
The string of beads sign is the description typically given to the appearance of the renal artery in fibromuscular dysplasia (FMD) but may also be used to describe the appearance of splanchnic arteries in segmental arterial mediolysis (SAM). It refers to the appearance arising from the stenoses ...
Staghorn calculi, also sometimes called coral calculi, are renal calculi that obtain their characteristic shape by forming a cast of the renal pelvis and calyces, thus resembling the horns of a stag.
For a general discussion of renal calculi please refer to nephrolithiasis.
The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith. The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall. Phleboliths on the other hand usually have imperceptible walls (although up to 8% m...
Scrotal cystoceles are a type of urinary bladder hernia, where the bladder herniates into the scrotum.
Scrotal sac will contain fluid. Emptying of a scrotal cystocele with voiding is an im...
Fournier gangrene is a necrotising fasciitis of the perineum. It is a true urological emergency due to the high mortality rate but fortunately the condition is rare.
Fournier gangrene is typically seen in diabetic men aged 50-70 but is rarely seen in women. Other than age, predisp...
Neuroblastomas are tumours of neuroblastic origin. Although they may occur anywhere along the sympathetic chain, the vast majority arise from the adrenal gland.
They represent the most common extracranial solid childhood malignancy and are the third commonest childhood tumour after leukaemia an...
Hyperparathyroidism is the effect of excess parathyroid hormone (PTH) in the body. It can be primary, secondary or tertiary. There are many characteristic imaging features, predominantly involving the skeletal system.
Increased levels of the PTH lead to increased osteoclastic activit...
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...
PI-RADS (Prostate Imaging Reporting and Data System) refers to a structured reporting scheme for evaluating the prostate for prostate cancer. It is designed to be used in a pre-therapy patient.
The original PI-RADS score was annotated, revised and published as the second version, PI-RADSv2 6 by...
The scrotum (plural: scrota) is a dual-chambered protuberance of skin and muscle that contains the testes, epididymides, and spermatic cord. It consists of two chambers separated by a septum. It is an extension of the perineum, and is located between the penis and anus.
The recipients of renal transplants are susceptible to a number of complications.
Renal transplant complications
These can be broadly categorised as perirenal, renal parenchymal, renal collecting system, and/or renal vascular complications 1,2:
renal transplant rejection
Sickle cell disease (SCD) is a hereditary (autosomal recessive) condition resulting in the formation of abnormal haemoglobin (a haemoglobinopathy), which manifests as multisystem ischaemia and infarction, as well as haemolytic anaemia.
There is no recognised gender predilection. ...
Skene duct cysts are retention cysts that form secondary to inflammatory obstruction of the paraurethral ducts (Skene ducts) in females.
The cysts are lined by stratified squamous epithelium due to their origin from the urogenital sinus.
The rim sign can be seen in association with chronic hydronephrosis.
In patients with chronic hydronephrosis, in all forms of contrast-enhanced imaging of the obstructed kidney, enhancement may occur in the residual, but markedly atrophic, renal parenchyma, surrounding the dilated calyces and ...
Cannonball metastases refer to large, well circumscribed, round pulmonary metastases that appear, well, like cannonballs. The French term "envolée de ballons" which translates to "balloons release" is also used to describe this same appearance.
Metastases with such an appearance are classically...
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...
Rim sign in renal vascular compromise is seen in major renal vascular compromise.
It can be seen in:
renal artery obstruction from embolism, thrombosis or dissection
renal vein thrombosis
acute tubular necrosis
At contrast-enhanced CT or MRI, a thin (1-3 mm) rim of su...
Renal arterial cut-off sign, as the name suggests, is an abrupt termination of the contrast-opacified lumen of the renal artery. It may or may not be associated with contrast extravasation.
It is seen in a vascular injury, e.g. segmental or main renal artery thrombosis or occlusion.
The pampiniform plexus (plural: plexuses) is the venous network of approximately 10 veins draining the testis and epididymis. The network surrounds the testicular artery in the spermatic cord and lies anterior to the ductus deferens. Each network coalesces to form the testicular veins.
A putty kidney refers to a pattern of renal calcification associated with renal tuberculosis conventionally described on plain radiography. Calcification characteristically is very homogeneous and ground glass-like, representing calcified caseous tissue 3,4. Premkumar et al. labelled calcificati...
A phantom calyx is a solitary calyx which fails to opacify with contrast amidst an otherwise well-opacified pelvicalyceal system. It is due to an intrarenal process which has infiltrated and caused obliteration of the involved collecting system element.
It may be seen in:
tumour: especially tr...
Perirenal cobwebs are the presence of prominent perinephric septa. It is best appreciated on CT images.
The cobweb is considered to be due to engorged venous collaterals or due to oedema and fluid extravasation into the perirenal space 1.
Perirenal cobwebs may be seen in many benign...
The term fornix (plural: fornices) is used for anatomical structures in multiple organ systems that all share an arch-like morphology:
History and etymology
Fornix is Latin for...
Striated nephrogram, originally described on plain film urography, but just as easily seen on CT urography represents linear bands of contrast extending from the medulla of the kidney towards the cortex.
Striations result from stasis and concentration of contrast material in oedemato...
The inguinal canal is a passage in the anterior abdominal wall that transmits structures from the pelvis to the perineum formed by the fetal migration of the gonad from the abdomen into the labioscrotal folds.
The inguinal canal has an oblique course, is 4 cm in length and has tw...
Prostatic utricle cyst (PUC) is an area of focal dilatation that occurs within the prostatic utricle.
They are midline cystic masses in the male pelvis and can be very difficult or impossible to distinguish from a Mullerian duct cyst.
Utricle cysts are most often detected in the ...
The adrenal (suprarenal) glands are paired organs of the endocrine system, often asymmetric in shape.
Each gland is enclosed in the perirenal fascia and each has a body and two limbs: a medial limb and a lateral limb. However, the right adrenal gland is usually more pyramidal in...
Lymphangioleiomyomatosis (LAM) is a rare multi-system disorder that can occur either sporadically or in association with the tuberous sclerosis complex (TSC) and is often considered a forme fruste of TSC.
It almost exclusively affects women of child-bearing age 7. The estimated in...
Testicular cystic lesions are a relatively common occurrence on testicular ultrasound. They result from widely variable pathological entities ranging from benign to malignant. These entities include:
simple testicular cyst
tunica albuginea cyst (mesothelial cyst)
cystic transformation of rete...
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...
Renal trauma can result from direct, blunt, penetrating and iatrogenic injury.
Renal injuries account for ~10% of abdominal trauma, and thus the demographic of affected individuals reflects that population. The incidence of renal injuries increases in pre-existing congenital or ac...
The vesicoureteric junction (VUJ) is the most distal portion of a ureter, at the point where it connects to the urinary bladder.
VUJ is synonymous with "ureterovesicular junction" (UVJ). It is nearly synonymous with "ureteral orifice" (UO), although depending on the context, the V...
Another commonly used classification scheme used by urologists and rehabilitation specialists, described by Wein, classifies bladder impairment following spinal cord injury according to the level of injury:
suprasacral (infrapontine) bladder - upper motor neuron lesion, releasing the sacral mic...
Emphysematous pyelitis is isolated gas production inside the excretory system, secondary to acute bacterial infection. It is a relatively benign entity and needs accurate differentiation from the far more serious emphysematous pyelonephritis, which is gas production from an infection in the rena...
Renal osteodystrophy (ROD), also known as uraemic osteopathy, is the constellation of musculoskeletal abnormalities that occur in patients with chronic renal failure, due to concurrent and superimposed:
osteomalacia (adults) / rickets (children)
secondary hyperparathyroidism: abnormal calcium ...
Abdominal manifestations of sickle cell disease (SCD) are wide and can involve many organs.
For a general discussion, please refer to sickle cell disease.
may occur transiently with the sequestration syndrome, where rapid pooling of blood occurs in the spleen, resulting ...
Emphysematous pyelonephritis refers to a morbid infection of kidneys, with characteristic gas formation within or around the kidneys. If not treated early, it may lead to fulminant sepsis and carries a high mortality.
The patient usually presents with flank pain, urinary ...
The kidneys are paired retroperitoneal organs that lie at the level of the T12 to L3 vertebral bodies.
The kidneys are located on the posterior abdominal wall, with one on either side of the vertebral column, in the perirenal space. The long axis of the kidney is parall...
Renal forniceal or calyceal rupture is the radiographic finding of a perirenal urine leak as a result of ureteric obstruction.
The renal fornices are the thin pointed projections, arising from the lateral aspects of each minor calyx, and extending a short distance into the renal column...