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.

740 results found
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Watermelon skin sign

The watermelon skin sign refers to diffuse, radiating, streaky areas of low signal intensity in prostate on T2WI in patients with prostatic tuberculosis 1.  
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Testicular microlithiasis

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...
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Nutcracker syndrome

Nutcracker syndrome is a vascular compression disorder and refers to the compression of the left renal vein between the superior mesenteric artery (SMA) and aorta. This can lead to renal venous hypertension, resulting in rupture of thin-walled veins into the collecting system with resultant haem...
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Sexual differentiation

Sexual differentiation refers to the embryological development of male and female phenotypes. Unlike sexual genotype which is determined at the time of fertilisation, the male and female phenotypes do not begin to differentiate substantially until the seventh week of gestation.  Males  Y chrom...
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Superficial perineal pouch

The superficial perineal pouch is an anatomic space below the perineal membrane in the urogenital triangle of the perineum. Gross anatomy The superficial perineal pouch is below the perineal membrane in the urogenital triangle, anterior to the transverse line between the ischial tuberosities. ...
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Schistosomiasis (urinary tract manifestations)

Bladder schistosomiasis, also known as bilharzia of the bladder, is a major health problem in developing parts of the world predisposing individuals to squamous cell carcinoma. Epidemiology Schistosomiasis is very common, affecting over 200 million people, with the vast majority (85%) in Afric...
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Recreational drug use (radiological manifestations)

Radiological manifestations of recreational drug use are not infrequently seen as the use of recreational drugs is widespread. Epidemiology Interestingly, recent reports have suggested a decreasing incidence of reported drug use in the general population over the past decade, but it remains th...
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Cobb's collar

Cobb's collar(also known as a Moormann's ring) is an uncommon finding on a paediatric voiding/micturating cystourethrogram (VCUG), but an indentation of the bulbar urethra is seen in more than half of boy's who are cystoscoped, as the narrow represents two different phenomena3-4. Pathology One...
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Scrotal pyocoele

Scrotal pyocoeles are purulent fluid collections in the scrotal sac that generally occur in conjunction with epididymo-orchitis. Pathology Scrotal pyocoeles are typically a complication of epididymo-orchitis and testicular abscess but can also occur following trauma or surgery. The purulent fl...
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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) ...
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Hypertrophied column of Bertin

Columns of Bertin represent the extension of renal cortical tissue which separates the pyramids, and as such are normal structures. They become of radiographic importance when they are unusually enlarged and may be mistaken for a renal mass (renal pseudotumour). Nomenclature of such enlarged co...
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Chronic kidney disease

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...
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Multilocular cystic renal tumours

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...
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Cyst

A cyst is an abnormal fluid filled structure which is lined by epithelium. This distinguishes it from a pseudocyst with lacks an epithelial lining and instead has a vascular and fibrotic capsule Cysts are extremely common and found in many organs. Examples include: renal cysts hepatic cysts ...
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Penis

The penis is the most distal part of the male urogenital system. Gross anatomy The gross anatomy of the penis can be broken into five sections:  Skin loosely connected to the tunica albuginea distally folded to form the prepuce (foreskin) at the corona of the penis the internal layer of th...
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Haemorrhage exclusion sign (prostate)

The haemorrhage exclusion sign can be a useful MRI finding following prostate biopsy. Pathology 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...
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Benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) or benign prostatic enlargement (BPE) is an extremely common condition in elderly men and is a major cause of bladder outflow obstruction.  Terminology The term benign prostatic hypertrophy was formerly used for this condition, but since there is actually an ...
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Cremaster muscle

The cremaster muscle is the thin fascial muscle of the spermatic cord made of skeletal muscle. It is also referred to as cremaster fascia or simply the cremaster. Its action is to retract the testes, important in thermoregulation and spermatogenesis.  Gross anatomy It is derived from the inter...
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Cremasteric artery

The cremasteric artery is a small branch of the inferior epigastric artery that enters the deep inguinal ring of the inguinal canal and supplies the layers of the spermatic cord and also the skin of the scrotum, including the cremaster muscle. History and etymology The word "cremaster" derives...
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Epididymis

The epididymis (plural: epididymides) is situated adjacent to the testes within the scrotal sac. Its primary function is the collection, maturation and transport of sperm via the ductus deferens. Gross anatomy The epididymis is an elongated structure, posterolateral to testes, with head, body ...
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Testicular arteries

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.  Gross anatomy Origin As paired structures they arise symmetrically, slightly...
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Renal cell carcinoma

Renal cell carcinomas (RCC) are primary malignant adenocarcinomas derived from the renal tubular epithelium and are the most common malignant renal tumour. They usually occur in 50-70-year-old patients and macroscopic haematuria occurs in 60% of the cases.  On imaging, they have a variety of ra...
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Renal cyst

Renal cysts are a common finding in the kidneys. Findings common to all "simple" renal cysts are well-marginated, thin walls with no enhancement of the cyst. They can be diagnosed on ultrasound, CT, or MRI. A cystic lesion in the kidney that deviates from the typical "simple" cyst appearance sho...
Article

Bartholin's glands

The Bartholin's glands (or greater vestibular glands) are paired pea-sized structures lying on either side of the vaginal opening and are homologous to the bulbourethral (Cowper's) glands in the male Gross anatomy These glands are described as less than 1 cm in diameter and found behind the po...
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Renal angiomyolipoma

Renal angiomyolipomas (AMLs) 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 vascu...
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Renal papillary necrosis

Renal papillary necrosis refers to ischemic necrosis of the renal papillae. Necrosis also occurs in the medullary pyramids. Clinical features Patients can present with both acute episodes or chronic renal papillary necrosis. Calyceal or ureteral obstruction by sloughed papillae manifest with f...
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Testicular cancer

Testicular cancers are the most common neoplasm in men between the ages of 20 and 34. Epidemiology 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 ...
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Ischiocavernosus muscle

The ischiocavernosus muscles are one of the three main muscles found in the superficial perineal pouch along with the bulbospongiosus and superficial transverse perineal muscle.  Summary origin: ischial tuberosity and ramus insertion: males: corpus cavernosum females: clitoris blood supply...
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Bulbospongiosus muscle

The bulbospongiosus is a muscle found in the superficial perineal pouch which covers the bulb of the penis in males and the bulb of the vestibule in females. Summary origin: median raphe and perineal body insertion: dorsum of penis/clitoris, perineal membrane innervation: pudendal nerve blo...
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Inguinal canal

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. Gross anatomy The inguinal canal has an oblique course, is 4 cm in length and has tw...
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Fishhook ureters

Fishhook ureters, also known as J-shaped ureters or hockey stick ureters describe the appearance of the distal ureter in patients with significant benign prostatic hypertrophy. It has also been used to describe the appearance of a retrocaval ureter further up, as the right ureter hooks behind th...
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Bosniak classification system of renal cystic masses

The Bosniak classification system of renal cystic masses divides renal cystic masses into five categories based on imaging characteristics on contrast-enhanced CT. It is helpful in predicting a risk of malignancy and suggesting either follow up or treatment. Classification Bosniak 1 simple cy...
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Multiple endocrine neoplasia type II

Multiple endocrine neoplasia type II (MEN2) is also known as mucosal neuroma syndrome or multiple endocrine adenomatosis. It is a collection of syndromes characterised by the presence of multiple endocrine tumours.  They are autosomal dominant in inheritance, and share medullary thyroid carcino...
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Multiple endocrine neoplasia type IIb

Multiple endocrine neoplasia (MEN) type IIb, also known as MEN type 3 (MEN3) 3 or mucosal neuroma syndrome 2, accounts for only 5% cases of MEN2 and is characterised by: pheochromocytoma(s): in 50% of patients, often bilateral, and can be extra-adrenal medullary thyroid cancer: 100% of patient...
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Multiple endocrine neoplasia syndromes

Multiple endocrine neoplasia (MEN) syndromes are a collection of syndromes characterised by the presence of, as the name would suggest, multiple endocrine tumours. They are autosomal dominant in inheritance. MEN1 (Wermer syndrome) MEN2 (multiple endocrine adenomatosis) MEN2a (Sipple syndrome)...
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Fat containing renal lesions

There are numerous fat containing renal lesions, including: renal angiomyolipoma renal cell carcinoma Wilms tumour renal oncocytoma renal or perirenal lipoma Non-mass lesions may also occasionally contain fat: renal junction line fat in a renal scar renal sinus lipomatosis xanthogranul...
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Bladder outlet obstruction

Bladder outlet obstruction (BOO) can arise from a number of conditions affecting the urethra and/or bladder outlet.  Clinical presentation Patients often present with difficulty in urination, retention and urinary discomfort 2. Pathophysiology Obstruction can be caused by multiple etiologies...
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Scrotal tunica cyst

Scrotal tunica cysts are paratesticular cystic lesions. They include: tunica vaginalis cysts tunica albuginea cysts Radiographic features Ultrasound  Typically seen as a simple appearing paratesticular cystic lesion not in the region of the epididymis. See also paratesticular lesions
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Renal artery stenosis

Renal artery stenosis (RAS) refers to a narrowing of a renal artery. When the process occurs slowly, it leads to secondary hypertension. Acute renal artery stenosis does not lead to hypersecretion of renin. Pathology When the stenosis occurs slowly, collateral vessels form and supply the kidne...
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Renal amyloidosis

Renal amyloidosis is rare as an isolated entity but can be associated with systemic amyloidosis. Renal involvement from amyloidosis in pathological specimens is quite common. However, renal function compromise is rare. Clinical presentation It usually manifests as nephrotic syndrome: fever a...
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Metallic ureteral stents

Patients with malignant ureteric obstruction and poor life expectancy usually require placement of ureteral stents to relieve the urinary obstruction and as a palliative measure to reduce pain and avoid major operation. Metallic ureteric stents have recently been developed to try and offer bett...
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Low signal intensity renal parenchyma

There are relatively few of causes of low signal intensity renal parenchyma. Causes include: haemolysis paroxysmal nocturnal haemoglobinurea. mechanical: malfunctioning prosthetic cardiac valve sickle cell disease infection hemorrhagic fever with renal syndrome (HFRS) vascular disease ac...
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Haematospermia

Haematospermia refers to the presence of blood in semen or ejaculatory fluid. It is a symptom that can cause great anxiety to patients despite commonly being of benign aetiology. Pathology Aetiology urogenital infections including sexually transmitted disease commonest cause in <40 years of ...
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Tc-99m DMSA

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...
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Gas in the urinary bladder

There numerous causes of gas in the bladder. In the hospital setting by far the most common is the recent placement of an indwelling urinary catheter. Other causes include: iatrogenic IDC by far the most common cause cystoscopy, etc emphysematous cystitis intraluminal and intramural gas mo...
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Epidermoid cyst

The term epidermoid cyst can refer to a: epidermal inclusion cyst intracranial epidermoid cyst splenic epidermoid cyst spinal epidermoid cyst testicular epidermoid cyst
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Congenital anomalies of the male urethra

Congenital anomalies of the male urethra include various anomalies due to complex development of urethra. These anomalies can be isolated or in association with other coexisting anomalies. They can be categorised as following: congenital valves  posterior urethral valve anterior urethral valv...
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Bilateral testicular lesions

Bilateral testicular lesions have a relatively limited differential diagnosis.  Differential diagnosis Neoplastic  lymphoblastic leukemia (acute or chronic) lymphoma (non-Hodgkin's) primary testicular lymphoma is rare but the testes are often the site of lymphoma/leukemia recurrence due to ...
Article

Nephroptosis

Nephroptosis, also known as floating or wandering kidney and ren mobilis, refers to the descent of the kidney more than 5 cm or two vertebral bodies when the patient moves from a supine to upright position during IVU 1-2. Displacement can also occur medially across the midline, so-called medial...
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Paediatric renal tumours and masses

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. Commoner lesions Wilms tumour: common in older children 1-8 years old mesoblastic nephro...
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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...
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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...
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Adrenal insufficiency

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). Secondary adrenal ...
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Prune belly syndrome

Prune belly syndrome, also known as Eagle Barrett syndrome 3 or triad syndrome, is a rare anomaly comprising a specific constellation of features. It consists of three major findings: gross ureteric dilatation anterior abdominal wall underdevelopment (resulting in the "prune belly" appearance)...
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Bladder exstrophy

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. Epidemiology The estimated incidence of bladder exstrophy is 1:10,000-50,000 live births 4,6. There is a ...
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Neonatal hydronephrosis

Neonatal hydronephrosis is most commonly diagnosed antenatally as fetal pylectasis, and in the majority of cases is due to pelvi-ureteric junction (PUJ) obstruction.   Pathology Aetiology pelvi-ureteric junction (PUJ) obstruction (50% of cases 1,6) vesicoureteric reflux (~20% of cases 5) po...
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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...
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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...
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Zinner syndrome

Zinner syndrome is a triad of Wolffian duct anomalies that include 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, recurren...
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Congenital renal anomalies

Congenital renal anomalies comprise of vast spectrum of pathologies and include: renal agenesis renal dysgenesis congenital renal hypoplasia congenital megacalyectasis congenital cystic renal disease infantile polycystic renal disease: autosomal recessive polycystic kidney disease (ARPKD):...
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PET-CT indications

PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET). PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). F-18 is an unstable radioisotope and has a half-life of approx...
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Calyceal diverticulum

Calyceal diverticula, also known as pyelocalyceal diverticula are congenital outpouchings from the renal calyx or pelvis into the renal cortex. These diverticula are lined with transitional cell epithelium. Epidemiology Relatively uncommon, seen in 0.21% to 0.60% of intravenous urograms (IVU)....
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Delayed nephrogram

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...
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Milk of calcium

Milk of calcium (MOC) is a term given to dependent, sedimented calcification within a cystic structure or hollow organ. This sort of colloidal calcium suspension layering can occur in various regions: renal cysts: milk of calcium in renal cyst (most common) breast cysts: milk of calcium in bre...
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Renal milk of calcium cysts

Renal milk of calcium cysts refer to the appearance of a calcium precipitate found within a calyceal diverticulum that has lost communication with the collecting system or within a simple renal cyst.  Clinical presentation Renal milk of calcium cysts are typically asymptomatic.  Pathology Re...
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Rhabdomyosarcoma (genitourinary tract)

Rhabdomyosarcomas of the genitourinary tract are uncommon tumours occurring in pelvic organs.  It is a disease nearly exclusive to the paediatric population.  For a general discussion of this type of tumour, please refer to the article on rhabdomyosarcomas. Epidemiology The peak incidence of ...
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Pelvic lipomatosis

Pelvic lipomatosis (also known as pelvic fibrolipomatosis) represents excessive deposition of fat in pelvis due to overgrowth of adipose cells leading to compression of pelvic organs. Epidemiology The condition usually presents in patients 20-50 years of age. The condition is predominantly (2/...
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Height adjusted total kidney volume

Height adjusted total kidney volume (HtTKV) is used in patients with autosomal dominant polycystic kidney disease to predict the onset of renal insufficiency. There is strong evidence to indicate that baseline htTKV predicts, with good sensitivity and specificity, the development of renal insuff...
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MR defaecating proctography

MR defecography is a dynamic study for evaluation of the pelvic floor and pelvic organ prolapse. Phases There are four phases of evaluation: rest squeeze strain (Valsalva) defaecation Method of evaluation Many variations in the techniques described below exist. Patient preparation Typi...
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Empyema

Empyemas are purulent inflammatory collections within a body cavity. They are similar to abscesses, which arise within parenchymal tissue rather than occupying a pre-existing anatomical space. Terminology Colloquially, the term empyema is used to refer to thoracic empyemas but there are variou...
Article

Polyorchidism

Polyorchidism (or supernumerary testes) refers to the presence of more than two testes and is a very rare congenital anomaly. The supernumerary testis can be usually located inside the scrotum (75% of the patients) or less commonly in the inguinal canal, the retroperitoneum, or the abdominal cav...
Article

Medical devices in the abdomen and pelvis

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. Gastrointestinal tubes stomac...
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Cystitis glandularis

Cystitis glandularis are small focal polypoid bladder mucosal thickenings and irregularities due to metaplasia of the urothelium (to mucin producing goblet cells) which proliferates into buds growing down into the lamina propria; this entity is closely related to cystitis cystica, with which it ...
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

Testicular trauma

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 frac...
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Squamous cell carcinoma (urinary bladder)

Squamous cell carcinoma of the urinary bladder is rare and accounts for only ~3-8% 1,2 of all bladder cancers (90% are transitional/urothelial cell carcinomas) but nevertheless, SCC is the most common type of nontransitional cell carcinoma involving the bladder 2. SCC of the bladder is observed ...
Article

Scrotolith

Scrotoliths, also known as scrotal pearls, are benign incidental extra testicular macro-calcifications within the scrotum. They frequently occupy the potential space of the tunica vaginalis or sinus of the epididymis. They are usually of no clinical significance 1-2. Clinical presentation Most...
Article

Renal vein anomalies

There are several variations in renal venous anatomy. Some of these are specific to the left renal vein. Left renal vein anomalies are generally classified into four types 2: type I  the ventral pre-aortic limb of the left renal vein is obliterated, but the dorsal retro-aortic limb persists a...
Article

CT polytrauma (technique)

CT polytrauma/multitrauma (also called trauma CT) is an increasingly used test in the patient with multiple injuries sustained after significant trauma. There is some evidence that trauma patients who undergo whole body CT (WBCT) / panscan have better survival than patients who undergo selectiv...
Article

Chronic prostatitis

Chronic prostatitis is a heterogeneous condition characterised by chronic inflammation of the prostate gland. Under the National Institutes of Health (NIH) classification system this may encompass chronic bacterial prostatitis chronic prostatitis and chronic pelvic pain syndrome (CPPS) Other...
Article

Adrenal calcification

Adrenal calcification is not a rare finding in healthy asymptomatic people and is usually the result of previous haemorrhage or tuberculosis. Addison disease patients only occasionally develop calcification.  Pathology Aetiology Haemorrhage sepsis: Waterhouse-Friderichsen syndrome blunt abd...
Article

AAST kidney injury scale

The American Association for the Surgery of Trauma (AAST) renal injury scale 3-4 is the most widely used grading system for renal trauma at the time of writing (late 2016). Severity is assessed according to the depth of renal parenchymal damage and involvement of the urinary collecting system a...
Article

Granulomatous prostatitis

Granulomatous prostatitis is a nodular form of chronic prostatitis. It is usually diagnosed on biopsy. Pathology Causes idiopathic infection iatrogenic BCG post-radiotherapy systemic disease: sarcoidosis autoimmune Subtypes Several classification systems exist. A frequently used clas...
Article

Prostatitis

Prostatitis refers to an infection or inflammation of the prostate gland that presents as several syndromes with varying clinical features. Prostatitis is a clinical diagnosis and imaging is useful to evaluate abscess formation.  The National Institutes of Health (NIH) classified prostatitis in...
Article

Renal artery

The renal arteries originate from the abdominal aorta  and enter the renal hila to supply the kidneys.  Any variant in arterial supply is important to clinicians undertaking surgery or other interventional renal procedures. Gross anatomy Origin They arise from the abdominal aorta at the L1-2 ...
Article

Prostate

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...
Article

Cortical rim sign

The cortical rim sign is useful in distinguishing acute pyelonephritis from a segmental renal infarct and is seen on contrast enhanced CT or MRI. The wedges of reduced enhancement seen in the setting of acute pyelonephritis represent oedema and ischaemia which involves the whole wedge of renal ...
Article

Nephrotic syndrome

Nephrotic syndrome (NS) results from loss of plasma proteins in the urine and characterised by hypoalbuminemia, hyperalbuminuria, hyperlipidemia, and oedema. It may be caused by primary (idiopathic) renal disease or by a variety of secondary causes. Clinical presentation Patients present with ...
Article

Kidneys

The kidneys are paired retroperitoneal organs that lie at the level of the T12 to L3 vertebral bodies. Gross anatomy Location 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...
Article

Claw sign (mass)

The claw sign is useful in determining whether a mass arises from a solid structure or is located adjacent to it and distorts the outline. It refers to the sharp angles on either side of the mass, which the surrounding normal parenchyma forms when the mass has arisen from the parenchyma. As suc...
Article

Bullet and bodkin sign

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...
Article

Cannonball metastases (lungs)

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...
Article

Calyceal crescent sign

The calyceal crescent sign (Dunbar crescents) refers to the early intravenous pyelogram (IVP) appearance of markedly dilated renal calyces. It is formed by early contrast opacification of the dilated collecting ducts and ducts of Bellini with the characteristic shape as a result of the associate...

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