Pelviureteric junction (PUJ) obstruction/stenosis, also known as ureteropelvic junction (UPJ) obstruction/stenosis, can be one of the causes of an obstructive uropathy. It can be congenital or acquired with a congenital PUJ obstruction being one of the commonest causes of antenatal hydronephrosi...
Behçet disease is a multisystemic 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 ...
Congenital megacalyces is an incidental finding which mimics hydronephrosis. It is a result of underdevelopment of the renal medullary pyramids with resultant enlargement of the calyces. It is more frequently seen in males.
The enlarged, floppy calyces predispose to stasis, infection and calcul...
Epithelioid angiomyolipomas (EAML) are rare variants of the more common renal angiomyolipoma. They have malignant potential.
Like more common renal angiomyolipomas, EAMLs are considered perivascular epithelioid cell tumours (PEComas). EAMLs were regarded as a separate renal mass enti...
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.
An infected urachal cyst can occur at any age.
Medical devices in the abdomen and pelvis are important to be recognised, just like medical devices of the chest. Often we ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications.
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...
Testicular sarcoidosis is a rare manifestation of sarcoidosis. In cases of urogenital sarcoidosis, more commonly the epididymis is affected.
Testicular sarcoidosis is more common in African-American patients, as are other forms of sarcoidosis 1. Up to 5% of patients with chronic s...
Tc-99m DTPA (diethylene-triamine-pentaacetate) is one of the technetium radiopharmaceuticals used in renal imaging and primarily used to measure the glomerular filtration rate (GFR).
photon energy: 140 KeV
physical half-life: 6 hours
biological half-life: 2.5 hours
Tc-99m DMSA (dimercaptosuccinic acid) is a technetium radiopharmaceutical used in renal imaging to evaluate renal structure and morphology, particularly in paediatric imaging for detection of scarring and pyelonephritis. DMSA is an ideal agent for the assessment of renal cortex as it binds to th...
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)
Tc-99m MAG3 (mercaptoacetyltriglycine) is one of the technetium radiopharmaceuticals used in renal imaging.
photon energy: 140 KeV
physical half life: 6 hours
biological half life: 4 hours
normal distribution: kidneys (100%)
uptake by tubular secretion (9...
A delayed nephrogram, commonly described on plain film urography, but also visible on CT urography, is when there is absence or reduction of the normal renal parenchymal enhancement on nephrographic phase images.
A delayed nephrogram is characteristically unilateral and is usually distinguished...
The testes, also known as the testicles, are the male gonads and are contained within the scrotum. The testes are responsible for the 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.
Spermatoceles are a common type of extratesticular cyst, and represents cystic dilatation of tubules of the efferent ductules in the head of the epididymis.
Usually a painless, incidental finding but can present as a mass lesion if large 3.
Spermatoceles are u...
The differential diagnosis for extratesticular cystic lesions includes:
loop of bowel from an inguinal hernia
Very rarely, a scrotal mesothelioma may present as a cystic mass.
Simple testicular cysts are usually nonpalpable and thus are detected incidentally.
Testicular cysts require no treatment when discovered.
anechoic with posterior acoustic enhancement
no flow on colour Doppler
Hydroceles are acquired or congenital serous fluid collections 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, hydroceles appear a...
Metastases to testis are a rare cause of a testicular mass and may be bilateral in up to 15% of patients.
Metastases to the testes are apparent in ~0.04% of autopsy studies in patients with known malignancy. The average age is 57 years, much older than the primary age for primary...
Paediatric renal tumours and masses are another group of diseases (just like cystic renal diseases in both the adult and child) that are bewildering in their number, nomenclature and overlapping findings.
Wilms tumour: common in older children 1-8 years old
Percutaneous renal biopsy, utilising either ultrasound or CT, allows for an accurate, reliable method of acquiring renal tissue for histopathological assessment.
The biopsy may be of a native or transplant kidney. It is divided into two types:
non-focal or non-targeted
focal or targeted (i.e....
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)
The central approach of renal transplant ultrasound is to evaluate for possibly treatable surgical or medical complications arising in the transplanted kidney.
Institutions vary in the exact schedule of renal transplant ultrasound assessment, but it is common to obtain an initial ultrasound 24-...
Adrenal adenomas are the most common adrenal mass lesion and are often found incidentally during abdominal imaging for other reasons. In all cases, but especially in the setting of known current or previous malignancy, adrenal adenomas need to be distinguished from adrenal metastases or other ad...
Adrenal myelolipomas are rare benign, and usually asymptomatic, tumours of the adrenal gland characterised by the predominance of mature adipocytes.
On imaging, they usually present as large masses with a variable amount of fat-containing components.
Rare tumours with estimated ...
Crossed fused renal ectopia 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 crossed ren...
Varicocele 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 a...
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 sometimes bilateral and is often located in the upper two-thirds of t...
Diverticula are outpouchings of a hollow viscus and can be either true or false.
Diverticulum is the singular form and diverticula is the correct Latin plural form. 'Diverticuli' and 'diverticulae' are erroneous and should not be used (cf. septum).
contains all layers of the...
The differential diagnosis for unilateral testicular lesions is wide-ranging.
seminoma (40-50% of tumours)
non seminomatous germ cell tumours:
testicular epidermoid (teratoma with ectodermal elements only)
Sarcoidosis is a systemic inflammatory disease of unknown origin characterised by the formation of non-caseating granulomas. Virtually any organ system may be involved. Although less common than pulmonary and mediastinal disease, abdominal sarcoidosis can mimic more common infectious or neoplast...
Adrenal insufficiency refers to inadequate secretion of corticosteroids (glucocorticoids and mineralocorticoids).
It may occur from partial or complete destruction of the adrenal cortex, in which case it is termed primary adrenal insufficiency (also known as Addison disease). Secon...
Adrenal metastases are the most common malignant lesions involving the adrenal gland. Metastases are usually bilateral but may also be unilateral. Unilateral involvement is more prevalent on the left side (ratio of 1.5:1).
They are present at autopsy in up to 27% of patients with ...
Adrenal lesions cover a broad spectrum from benign to neoplastic entities. Due to increased use of cross-sectional imaging they are frequently detected as incidental lesions ("incidentalomas"). If found incidentally, please refer to the Management of incidental adrenal masses: American College o...
Adrenal haemorrhage can result from a variety of traumatic and non-traumatic causes. When unilateral, it is often clinically silent. In contrast, bilateral adrenal haemorrhage can lead to catastrophic adrenal insufficiency.
The large majority of patients with unilateral a...
Adrenal lymphangiomas, also known as cystic adrenal lymphangiomas, are rare, benign cystic adrenal lesions.
Adrenal lymphangiomas are extremely rare; prevalence is estimated at 0.06% 8. They can occur at any age, with a peak incidence between the 3rd and 6th decades of life. Accor...
The prostate gland is part of the male reproductive system and is the largest male accessory gland. It typically weighs between 20-40 grams with an average size of 3 x 4 x 2 cm. The prostate is comprised of 70% glandular tissue and 30% fibromuscular or stromal tissue 1-3 and provides ~30% of the...
The tuberous sclerosis diagnostic criteria have been developed to aid the diagnosis of tuberous sclerosis and have most recently been updated in 2012 by the International Tuberous Sclerosis Complex Consensus Group (at time of writing - 2018) 1.
The identification of...
Bartholin gland cysts are located in the posterolateral inferior third of the vagina and are associated with the labia majora.
Most patients are asymptomatic 4.
infection: may turn into Bartholin gland abscesses
rare instances of development of adenocarc...
Phaeochromocytomas are an uncommon tumour of the adrenal gland, with characteristic clinical, and to a lesser degree, imaging features. The tumours are said to follow a 10% rule:
~10% are extra-adrenal
~10% are bilateral
~10% are malignant
~10% are found in children
~10% are familial
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...
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 childbearing age 7. The estimated in...
Twinkling artifact is the result of intrinsic machine noise seen with colour Doppler ultrasound 1. It occurs as a focus of alternating colours on Doppler signal behind a reflective object (such as calculi), which gives the appearance of turbulent blood flow 2. It appears with or without an assoc...
The hymen (plural: hymens) is a thin fold of mucous membrane which extends across the vaginal opening, usually with some form of internal defect, which permits the free passage of normal menses.
It usually ruptures during coitus with the remnants, usually in the form of small tags of tissue ar...
There are several periurethral 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
male genitourinary trac...
Urethral diverticula, or urethroceles, are focal outpouchings of the urethra. They should not be confused with a ureterocele 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...
Alport syndrome is an X-linked dominant disease characterised by progressive sensorineural hearing loss, renal disease and, at times, ocular lesions.
sensorineural hearing loss: typically high frequency 2
anterior lenticonus: most commo...
An epididymal appendix (or alternatively appendix of the epididymis or appendix epididymis) is a testicular appendage that is a developmental remnant of the mesonephric duct (Wolffian duct) which can be found in the head of the epididymis 1. In 78% of the cases, it is stalked and is thus easily ...
A septate uterus is a common type of congenital uterine anomaly, and it may lead to an increased rate of pregnancy loss. The main imaging differential diagnoses are arcuate uterus and bicornuate uterus.
It is considered the commonest uterine anomaly (accounts for ~55% of such anom...
Cystic adrenal neoplasms are uncommon and only account for a minority of cystic adrenal lesions 3. They may be represented several histological types:
adrenal adenoma 1
adrenal cortical carcinoma 1,2
adrenal epithelioid angiosarcoma 2
teratoma (paediatric population) 4
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.
Both neuroblastoma and Wilms tumour occur in early childhood and typically present as large abdominal masses closely related to the kidneys. Distinguishing between the two is important, and a number of features are helpful.
calcification very common: 90%
encases vascular structu...
A cyst is an abnormal fluid-filled structure which is lined by epithelium; with one exception: lung cysts contain gas, not fluid. By contradistinction, a pseudocyst lacks an epithelial lining and instead has a vascular and fibrotic capsule.
Cysts are extremely common and found in most organs. E...
Hermaphroditism states are a result of abnormalities in embryonic development and may have mixed characteristics of each sex, with variable clinical manifestations. True hermaphroditism is deﬁned as the simultaneous presence in a single individual of both testicular and ovarian tissues, that may...
Multilocular cystic renal tumours (MCRT) are rare benign renal neoplasms occurring in a bimodal age distribution, involving young children and adults in the 4th and 5th decades.
For logical reasons, this article will discuss together the two ends of the spectrum of this disease, cystic partiall...
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 transition...
Syphilis is the result of infection with the gram negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately.
Despite the discovery of penicillin...
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...
The internal pudendal veins are the set of accompanying veins to the internal pudendal artery draining the perineal region to empty into the internal iliac vein.
inferior rectal veins
penile bulb and scrotum vein
clitoris and posterior labial vein
Increased renal echogencity is a nonspecific finding but can represent a number of underlying conditions.
chronic kidney disease: increased cortical echogenicity
sickle cell disease 4
echogenic renal pyramids - paediatric
Chronic renal transplant rejection is a form of renal transplant rejection. It usually later following transplantation.
Chronic rejection is defined as a gradual deterioration in graft function beginning at least 3 months after transplantation 3.
The creatinine levels may rise but ...
Adrenal abscesses are rare lesions affecting the adrenal glands and are usually encountered in the setting of disseminated infection.
Although cases have been described in both neonates and adults, no systematic literature is available on the epidemiology of adrenal abscesses.
AP oblique supine radiograph is normally performed when localising foreign bodies or lines within the abdominal cavity. Additionally, the oblique abdominal series can be utilised in the assessment of the upper intestinal tract during barium studies.
the patient is laying 30 de...
PA prone radiograph is rarely performed, often utilised when a patient is unable to lay supine. The projection is adequate for the examination of the abdominal cavities, however, not as practical for the renal structures due to magnification.
the patient is prone, either on th...
The Valsalva manoeuvre is the forced expiration of air against a closed airway, resulting in increased intra-abdominal, intrathoracic and pharyngeal pressure. It can be performed against a closed glottis or by one closing the mouth and pinching the nose while forcibly exhaling.
It is commonly u...
Hyperparathyroidism is the effect of excess parathyroid hormone 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 parathyroid hormone lead to increased osteoclas...
Hydrocele 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 oblite...
Pancake kidney (also known as discoid kidney, disc kidney, lump kidney, fused pelvic kidney or cake kidney) is a rare renal fusion anomaly of the kidneys of the crossed fused variety.
Pancake kidney may be an incidental finding. However, they can present clinically becaus...
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 ...
Fibromuscular dysplasia (FMD) is a heterogeneous group of vascular lesions characterised by an idiopathic, non-inflammatory, and non-atherosclerotic angiopathy of small and medium-sized arteries.
The prevalence is unknown 7. It is most common in young women with a female to male r...
The curlicue ureter sign1 is seen intravenous pyelogram in cases of ureteral herniation in sciatic hernia, causing a curled appearance of the herniated ureter. Although very rare, this sign is pathognomonic of sciatic hernia.
Ileovesicostomy (also known as "cutaneous ileocystostomy", "ileal chimney", or "bladder chimney") is an uncommon urologic diversion in which a loop of small bowel is anastomosed/augmented to the dome of the bladder. This loop of bowel then exits through a urostomy. The diversion is not continent...
Renal milk of calcium cysts refer to the appearance of a calcium precipitate found either within a calyceal diverticulum, that has lost communication with the collecting system, or within a simple renal cyst.
Renal milk of calcium cysts are typically asymptomatic.
Renal angiomyolipomas (AML) are a type of benign renal neoplasm encountered both sporadically and as part of a phakomatosis, most commonly tuberous sclerosis. They are considered one of a number of tumours with perivascular epitheloid cellular differentiation (PEComas) and are composed of vascul...
Computed tomography of kidneys, ureters and bladder (CT KUB) is a quick non-invasive technique for diagnosis of urolithiasis. It is usually considered the initial imaging modality for suspected urolithiasis in an emergency setting 1.
identification of calc...
A subcapsular perirenal haematoma is a form of perirenal haematoma where blood accumulates beneath the renal capsular margin.
It can arise from a number of causes
trauma, important in assessing renal trauma grading
post procedural, e.g. extracorporeal shock-wave lithotripsy (ESWL) ...
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)...
Perirenal lymphoceles are the most common cause of perinephric fluid collection. They can potentially occur in a post-transplant situation in up to 25% of cases.
Perirenal lymphocele is usually asymptomatic but they can be large enough to cause hydronephrosis or venous ob...
Thimble bladder is a descriptive term for extreme fibrosis and contracture of the bladder walls, resulting in a tiny bladder. The term is usually used to describe changes from advanced genitourinary tuberculosis.
Ketamine bladder or ketamine bladder syndrome refers to lower urinary tract symptoms associated with long-term ketamine use.
The presence of lower urinary tract symptoms in long-term ketamine users has been identified to be as high as 90% in some studies 1.
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 anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists.
Head and neck anatomy
Abdominal and pelvic anatomy
The tunica albuginea (TA) forms the fibrous covering of the testis and is itself covered by the serous layer, the tunica vaginalis. The covering is total, except for at the point of attachment of the epididymis, and a small defect posteriorly where the spermatic cord vessels enter and leave the ...
An adrenal collision tumour or collision tumour of the adrenal gland is an uncommon condition where two histologically distinct tumours abut each other or are in close proximity in the same adrenal gland.
Collision tumours have been reported in nearly every organ, for example, collis...
Tamm-Horsfall proteins, also known as uromodulin, may be a cause of echogenic renal pyramids in a neonate.
Tamm-Horsfall proteins are physiologically excreted by the renal tubular epithelium. They are most often encountered on neonatal renal ultrasound, where the concentrated proteins in the re...
Post-transplant lymphoproliferative disorder (PTLD), also referred as post-transplant lymphoproliferation disorder, represents a variety of conditions ranging from lymphoid hyperplasia to malignancy, included in the 2008 WHO classification of tumours of haematopoietic and lymphoid tissues. It ca...
Tuberous sclerosis, 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 an i...
Clear cell sarcomas of the kidney (CCSK) are a rare mesenchymal renal tumour that account for ~5% of primary renal neoplasms in the paediatric population 1.
Clear cell sarcoma of the kidney is the second most common primary malignant paediatric renal neoplasm after Wilms tumour, ...
Perinephric fluid collections are commonly seen after renal transplantation. The appearance of a perinephric fluid collection is often nonspecific but may be partially differentiated by when the transplant occurred.
Early post-transplant period (<4 weeks)
Ejaculatory duct cysts are a rare type of cyst of the prostate gland.
They occur due to obstruction of the ejaculatory duct which in turn can either be congenital or secondary (e.g. inflammation).
They are usually intraprostatic when small but may extend cephalad when large.
Benign hyperattenuating renal cysts are also known as hyperdense renal cysts.
They are frequently found in patients with either acquired cystic renal disease or autosomal dominant polycystic renal disease 1.
homogeneously hyperattenuating (even when a narro...
Urine represents the biofluid end-product of the renal filtration process. Normally it is a transparent, sterile, pale-yellow liquid (although clearly colour varies with the person's hydration status).
Urine is one of the most easily-accessible biofluids in the human body and has been intensiv...
The great vessel space is the fourth retroperitoneal space along with the anterior and posterior pararenal spaces, and the perirenal space 1,2. Unlike other retroperitoneal spaces, it is not well-defined by fascial planes and thus disease processes affecting other retroperitoneal spaces can also...