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
Article

Intratesticular haematoma

Intratesticular haematomas typically result from testicular trauma. Radiographic features isoechoic/hyperechoic region in the traumatised testicle, becoming more hypoechoic as it resolves lack of colour Doppler flow Differential diagnosis segmental testicular infarct testicular neoplasm g...
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Intratesticular varicocoele

Intratesticular varicocele is a rare entity, occurring in ~2% of symptomatic population. Pathology It is defined as dilated intratesticular veins seen in relation to the mediastinum testis and extending peripherally. It is usually seen in the presence of ipsilateral extratesticular varicocele....
Article

Intrathoracic kidney

An intrathoracic kidney is a very rare form of ectopic kidney. There has been no reported increased incidence of stones or infections as with other forms of ectopic kidneys. The adrenal glands are usually normal in location. Clinical presentation Intrathoracic kidneys are usually asymptomatic ...
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Intravenous urography

Intravenous urography (IVU), also referred as intravenous pyelography (IVP) or excretory urography (EU), is a radiographic study of the renal parenchyma, pelvicalyceal system, ureters and the urinary bladder. This exam has been largely replaced by CT urography.  Terminology Some prefer the ter...
Article

Iron deficiency anaemia

Iron deficiency anaemia is a common cause of anaemia and a common precipitant to radiological investigation. Epidemiology Amongst men and postmenopausal women, the incidence in the developed world is around 2%. Among premenopausal women, the incidence is greater and in most cases, investigatio...
Article

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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Jackstone calculus

Jackstone calculus is the name assigned to the appearance of a subset of urinary calculi. Pathology Jackstone calculi are almost always composed of calcium oxalate dihydrate. They are nearly always created, and thus, located, in the bladder rather than the upper urinary tract. They are compos...
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Junctional parenchymal defect of kidney

Junctional parenchymal defects in renal imaging are a normal variant. Pathology It results from the incomplete embryonic fusion of renunculi. Radiographic features Ultrasound It can be seen as a triangular echogenic cortical defect, frequently seen in upper lobe parenchyma. The defect is th...
Article

Juxtaglomerular cell tumour

Juxtaglomerular cell tumour (JGCT) is an infrequent renal tumour of the juxtaglomerular cells. These cells secrete renin and often cause severe hypertension and hypokalaemia. Epidemiology JGCT affects all age groups, but is most common in adolescents and young adults, with peak prevalence in t...
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Kerr kink

Kerr Kink a sign of renal tuberculosis. Scarring leads to a sharp kink at the pelvi-ureteric junction.
Article

Keyhole sign (posterior urethral valves)

The keyhole sign is an ultrasonographic sign seen in boys with posterior urethral valves. It refers to the appearance of the proximal urethra (which is dilated) and associated thick walled distended bladder which on ultrasound may resemble a key hole.
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...
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Kidney sweat sign

The kidney sweat sign applies to the presence of thin, hypoechoic, extracapsular fluid collections around kidneys in renal failure patients. This fluid is assumed to represent perirenal oedema. It can be appreciated on ultrasound, CT and MR imaging.  Differential diagnosis perirenal haematoma ...
Article

Lacuna magna

Lacuna magna (a.k.a. sinus of Guérin) is a congenital blind-ended pouch located dorsal to navicular fossa of penis separated by fold and both share an external common opening to external urethral meatus. This diverticulum is located above and parallel to the urethra.  Epidemiology Although it ...
Article

Lateral fossa

The lateral fossae are concave depressions of peritoneum in the paravesical space that lie between the lateral umbilical folds and the lateral parietal peritoneum. The lateral fossae are the smallest of the anterior paravesical fossae, and typically partially contain the cecum and/or sigmoid col...
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Lateral umbilical folds

The lateral umbilical folds are raised ridges of parietal peritoneum in the deep aspect of the anterior abdominal wall overlying the inferior epigastric vessels. The paired folds originate medial to the deep inguinal ring and end at the arcuate line on the posterior aspect of the anterior abdomi...
Article

Layers of the scrotum (mnemonic)

A handy mnemonic to recall the layers of the scrotum is: Some Damn Englishman Called It The Testes Mnemonic S: skin D: dartos fascia and muscle E: external spermatic fascia C: cremasteric fascia I: internal spermatic fascia T: tunica vaginalis T: tunica albuginea 
Article

Leiomyoma of the urinary bladder

Leiomyoma of the urinary bladder is a rare benign tumour predominantly found in women, although men can also be affected. The most common presenting complaints are urinary voiding symptoms such as obstruction and irritation.  It exhibits characteristics similar to those of uterine leiomyomas on...
Article

Lentiform fork sign

The lentiform fork sign has been described on MRI seen as bilateral symmetrical hyperintensities in the basal ganglia surrounded by a more/brightly hyperintense rim delineating the lentiform nucleus. It has been postulated to result from metabolic acidosis due to any cause 1, e.g. end stage ren...
Article

Leptospirosis

Leptospirosis results from infection of the zoonoses Leptospira sp. The condition can have multi-organ manifestations. Commonly affected organs include: lung: pulmonary leptospirosis liver: hepatic leptospirosis central nervous system: CNS leptospirosis skeletal muscle: muscular leptospirosi...
Article

Leukoplakia of the urinary tract

Leukoplakia of the urinary tract is a squamous metaplasia of the urothelium (keratinisation).  Clinical presentation Clinically the condition presents with haematuria in one-third of cases, dysuria, frequency and nocturia, and thus it can mimic cystitis. Passage of the desquamated keratinised ...
Article

Levator ani

The levator ani, also known as the muscular pelvic diaphragm, is the musculotendinous sheet that forms the majority of the pelvic floor, supports the pelvic viscera, and aids in urinary and faecal evacuation as well as maintaining continence. Gross anatomy The levator ani has three main compon...
Article

Leydig cell tumour of the testis

A Leydig cell tumour of the testis is an uncommon testicular neoplasm. Its imaging appearance on ultrasound and MRI is nonspecific, but clinically it is associated with serum hormonal imbalance. Epidemiology 1-3% of all testicular tumours, but the most common sex-cord stromal tumour. Tend to b...
Article

Liddle syndrome

Liddle's syndrome is an autosomal dominant condition which inhibits the normal degradation of the ENaC sodium channel, resulting in findings that mimic Conn's syndrome (hyperaldosteronism); hypernatraemia, hypokalaemia and elevated serum bicarbonate. Typically patients are asymptomatic other tha...
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Lipomatosis

Lipomatosis is a condition where there is diffuse excessive fat deposition within the body. This can especially affect certain regions. neck and upper region of trunk Madelung disease mediastinal lipomatosis heart lipomatous hypertrophy of the interatrial septum lipomatous metaplasia of th...
Article

Lithium-induced renal disease

Lithium-induced renal disease is characterised by a progressive decline in renal function, evidenced by increasing serum creatinine and decreased creatinine clearance. The lithium salt causes direct injury to the renal tubules. The duration of lithium therapy increases the risk of progression to...
Article

Lobar nephronia

Lobar nephronia refers to an intermediate stage between acute pyelonephritis and renal abscess, and is a focal region of interstitial nephritis.  It appears as a wedge of poorly perfused renal parenchyma, without a cortical rim sign. The condition is discussed further as part of the article on...
Article

Lobster claw sign (kidney)

Lobster claw sign refers to a urographic pattern of papillary excavation that may be seen with renal papillary necrosis. The lobster claw sign occurs when there is excavation around the edge of the papilla and the contrast material that extends into this excavated region looks like the "claws" ...
Article

Localised cystic renal disease

Localised cystic renal disease (LCRD) or localised cystic kidney disease is an uncommon, non-familial, non-progressive disease characterised by clusters of cysts within normal renal parenchyma. It can be confused with unilateral autosomal dominant polycystic kidney disease (ADPKD), multilocular ...
Article

Loopogram

A loopogram is a fluoroscopic study of an ileal conduit, which is a type of urinary diversion. Terminology This procedure is also known is an ileal conduitogram, ileal loopography or ileostoureterography.  Procedure It is a retrograde study in which contrast is injected via the anterior abdo...
Article

Loop-to-loop colon

The loop-to-loop colon describes an abnormal colonic course associated with the absence of the left kidney from the renal fossa.  The transverse colon extends to the lateral margin of the abdominal wall and the descending colon courses medially to fill the renal fossa, resulting in a "looped" c...
Article

Lower urinary tract symptoms

Lower urinary tract symptoms (LUTS) are a constellation of symptoms including 1: poor stream despite straining hesitancy, frequency and incomplete emptying of the bladder nocturia Although they are most frequently encountered in men with benign prostatic hypertrophy (BPH) they are also found...
Article

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...
Article

Lymphangioleiomyomatosis

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. Epidemiology It almost exclusively affects women of child-bearing age 7. The estimated in...
Article

Macronodular adrenal hyperplasia

Macronodular adrenal hyperplasia refers to a morphological type of adrenal hyperplasia in which there is adrenal enlargement in the form of large distinct nodules. It can be congenital or acquired. A specific subtype under this entity is adrenocorticotropin independent macronodular adrenocortic...
Article

Maiden waist deformity

Maiden waist deformity is the appearance of the deviation of bilateral ureters. This typically occurs in retroperitoneal fibrosis. In this condition, there is medial drawing of the ureter due to deposition of fibrous tissue in the lumbosacral junction. Due to involvement of both ureters, the cou...
Article

Malacoplakia of the urinary tract

Malacoplakia of the urinary tract is an uncommon chronic granulomatous inflammatory disease of the bladder wall. Malakoplakia (meaning "soft plaque") can affect any organ, but the urinary bladder is the commonest location. Epidemiology Malacoplakia has a peak incidence in middle age and has a ...
Article

Male pseudohermaphroditism

Male pseudohermaphroditism (MPH) is a variation of gender development.  Pathology Patients with male pseudohermaphroditism have 46 XY karyotype and may manifest as a female phenotype with various degrees of undervirilization secondary to partial androgen insensitivity.  Causes androgen insen...
Article

Male reproductive system

The male reproductive system (or tract) includes: penis testes epididymis ductus deferens ejaculatory duct seminal vesicles and prostate It can be imaged using almost the entire range of imaging modalities but ultrasound and MRI are most often used (in part because these modalities are n...
Article

Male urethra

The male urethra is a fibromuscular tube that drains urine from the bladder. It has a longer, more complicated, course than the female urethra and is also more prone to pathology. Gross anatomy The male urethra measures, on average, 18-20 cm in length. It commences at the internal urethral ori...
Article

Male urethral segments (mnemonic)

A helpful mnemonic to remember the 4 segments of the male urethra from proximal to distal. Pet My Big Penis P: prostatic M: membranous B: bulbous P: penile Posterior urethra equates to the prostatic and membranous urethras.  Anterior urethra equates to the bulbous and penile urethras. Rel...
Article

Management of incidental adrenal masses: American College of Radiology white paper

In 2017, the Adrenal Subcommittee of the Incidental Findings Committee of the American College of Radiology published a revised algorithm for the management of incidental adrenal masses in patients who are: adults (i.e. 18-year-old or over) asymptomatic for adrenal pathology referred for imag...
Article

Manta ray sign (bladder)

The manta ray sign is a radiographic appearance in bladder exstrophy. It describes wide midline separation of the pubic bones simulating the appearance of a manta ray swimming towards you 1. Differential diagnosis On a plain radiograph consider: open book pelvic injuries: the smooth arc of th...
Article

Mature metastasising teratoma

A mature metastasising teratoma is an uncommon complication of mature testicular teratomas, whereby distant metastatic deposits of histologically mature cells are encountered.  
Article

McCune-Albright syndrome

McCune-Albright syndrome (MAS) is a genetic disorder characterised by the association of: endocrinopathy: precocious puberty polyostotic fibrous dysplasia: more severe than in sporadic cases cutaneous pigmentation: coast of Maine 'cafe au lait' spots Clinical presentation Presentation is va...
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Medial fossa

The medial fossae are concave depressions of peritoneum in the paravesical space bounded by the medial umbilical folds and the lateral umbilical folds. The fossae are contained within the inguinal (Hesselbach’s) triangle. The right medial fossa typically partially contains the cecum and/or ileum...
Article

Medial umbilical folds

The medial umbilical folds are raised ridges of parietal peritoneum in the deep aspect of the anterior abdominal wall formed by the underlying medial umbilical ligaments. The paired folds run from pelvis to umbilicus. The medial umbilical ligaments are anatomical remnants of foetal umbilical art...
Article

Median umbilical fold

The median umbilical fold is a raised ridge of parietal peritoneum in the deep aspect of the anterior abdominal wall overlying the median umbilical ligament. It runs from the apex of the bladder to the umbilicus. The median umbilical ligament is the anatomical remnant of the foetal urachus. The ...
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...
Article

Medullary cystic disease complex

Medullary cystic disease complex belongs to group of paediatric cystic renal diseases charaterised by progressive tubular atrophy with glomerulosclerosis (chronic tubulointerstitial nephritis) and multiple small medullary cysts.  Epidemiology There is no recognised gender predilection Clinica...
Article

Medullary nephrocalcinosis

Renal medullary nephrocalcinosis is the commonest form of nephrocalcinosis and refers to the deposition of calcium salts in the medulla of the kidney. Due to the concentrating effects of the loops of Henle, and the biochemical milieu of the medulla, compared to the cortex, it is 20 times more co...
Article

Medullary nephrocalcinosis (mnemonic)

A common mnemonic used to remember the aetiology of medullary nephrocalcinosis is: HAM HOP Mnemonic H: hyperparathyroidism A: (renal tubular) acidosis M: medullary sponge kidney H: hypercalcemia / hypercalciuria O: oxalosis P: papillary necrosis See also renal papillary necrosis mnemon...
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Medullary sponge kidney

Medullary sponge kidney is a sporadic condition where the medullary and papillary portions of the collecting ducts are dysplastic, and dilated and in most cases develop medullary nephrocalcinosis.  Epidemiology The incidence of medullary sponge kidney is estimated at ≈1:5000. Clinical present...
Article

Megacystis megaureter syndrome

Megacystis megaureter syndrome describes the radiologic appearance of a large capacity thin-walled bladder and massive primary vesicoureteral reflux. Pathology The pathophysiology of these massively dilated ureters and the large capacity bladder is the constant recycling of large volumes of r...
Article

Megapolycalycosis

Megapolycalycosis is a rare congenital anomaly of the kidney which is characterized by dilatation and increase in number of the renal calyces without any distal obstruction. Pathology It is thought to develop due to an abnormal development of the renal medulla.  Due to the calyceal dilatation...
Article

Mesoblastic nephroma

Mesoblastic nephroma, also sometimes known as a congenital mesoblastic nephroma (CMN) or fetal renal hamartoma, is, in general, a benign renal tumour that typically occurs in utero or in infancy. Epidemiology It is the commonest neonatal renal tumour. Diagnosis is usually made in the antenatal...
Article

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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Metanephric adenoma of the kidney

Metanephric adenoma (MA) of the kidney is a type of benign renal neoplasm.  Epidemiology While it can present at any age 6, the peak age of occurrence is thought to be around the 5th to 6th decades 2. There may be a 2:1 female preponderance 2.  Clinical presentation Metanephric adenoma is as...
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Metanephric blastema

Metanephric blastema  (or metanephrogenic blastema) is one of the two embryological structure that give rise to the kidney, the other one being the ureteric bud. Related pathology Persistent metanephric blastema after 36 weeks of gestational age are called nephrogenic rests. They are associate...
Article

Metastases to testis

Metastases to testis are a rare cause of a testicular mass and may be bilateral in up to 15% of patients.  Epidemiology 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...
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Microlithiasis

Microlithiasis merely means very small stones and may refer to: testicular microlithiasis alveolar microlithiasis calyceal microlithiasis
Article

Middle adrenal artery

The middle adrenal (suprarenal) artery is one of the three adrenal arteries that supply the adrenal gland. Gross Anatomy Origin The middle suprarenal arteries arise from the aorta on each side between the inferior phrenic artery and the renal artery. They run laterally across the diaphragmati...
Article

Milk-alkali syndrome

Milk-alkali syndrome is the combination of: hypercalcaemia renal failure metabolic alkalosis It is due to the large amounts of calcium and alkali being ingested (e.g. milk and antacids for peptic ulcer disease treatment or calcium carbonate for osteoporosis). It is a cause of medullary nephr...
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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...
Article

Mixed gonadal dysgenesis

Mixed gonadal dysgenesis (MGD) is a type of gonadal dysgenesis characterised by gonadal asymmetry, and/or sex chromosomal mosaicism, as well as retained Müllerian ducts. Pathology Depending on the chromosomal composition, patients may have testes and/or streak gonads. Genetics affected indiv...
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Mixed epithelial and stromal tumour of the kidney

Mixed epithelial and stromal tumour (MEST) of the kidney is an uncommon and recently recognised distinct neoplasm that should be distinguished from other renal neoplasms.  Epidemiology There is a female preponderance 10:1 1 with tumours occurring predominantly in middle-aged peri-menopausal wo...
Article

Molar tooth sign (abdomen)

Abdominal molar tooth sign refers to the appearance of contrast media spilled out of the urinary bladder on CT cystography after extraperitoneal bladder rupture. Contrast flows out of the ruptured bladder, occupying preperitoneal cavum Retzii and surrounds the bladder in the shape of a molar to...
Article

Moth eaten calyces

Moth eaten calyx refers to the ragged, feathery calyceal outline due to irregular erosions of the calyx. It is one of the earliest excretory urographic appearance of genitourinary tuberculosis.  Pathology This appearance is due to necrotizing papillitis, which may further progress to form medu...
Article

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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MR spectroscopy in prostate cancer

MR spectroscopy is a promising development in the radiological evaluation of possible prostate malignancy.  The MR spectroscopic evaluation is mainly based on the choline peak elevation and choline-creatinine ratios. Choline/creatine to citrate ratios: > 0.5: suspicious > 0.8: very suspiciou...
Article

Mulberry stone

A mulberry stone is one of the types of urinary tract stones. It is formed of calcium oxalate dihydrate. It can be considered as a subset of a jackstone calculus which has a spiked appearance. When the stone has less well-developed spikes, it may appear to have a mamillated appearance, hence it ...
Article

Müllerian duct cyst

A Müllerian duct cyst is a cyst that arises from remnants of the Müllerian duct and is one of the midline cystic masses in the male pelvis. Epidemiology Müllerian duct cysts usually occur in the 3rd and 4th decades of life (whereas utricle cysts are most often detected in the 1st and 2nd decad...
Article

Multicystic dysplastic kidney

Multicystic dysplastic kidney (MCDK) is a type of non-heritable paediatric cystic renal disease. It results in multiple cysts being formed in utero in the affected kidney. Epidemiology Unilateral incidence is estimated at 1:2500-4000. There may be a predisposition for the left kidney, a slight...
Article

Multicystic mesothelioma

A multicystic mesothelioma is a rare benign sub type of  mesothelioma. Epidemiology They tend to occur in young females.  Pathology Typically comprises of multiple grape-like clusters of cysts which are lined with mesothelium and separated by fibrous tissue components. Risk factors previou...
Article

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...
Article

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)...
Article

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...
Article

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...
Article

Multiple filling defects of the ureter (differential)

Multiple filling defects within a ureter, as seen on conventional IVU or CT IVU, have a relatively small differential including: spreading or multifocal transitional cell carcinoma (TCC) vascular indentations multiple ureteral stones (steinstrasse) blood clots ureteritis cystica Stevens-Jo...
Article

N-acetylcysteine

N-acetylcysteine (NAC) if often used as a prophylaxis against contrast-induced nephropathy. Protocols for administration vary widely from institution to institution and the true efficacy is still controversial. A typical protocol is [1-2]: 600 mg acetylcysteine twice daily on the day of the ex...
Article

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...
Article

Nephroblastomatosis

Nephroblastomatosis refers to diffuse or multifocal involvement of the kidneys with nephrogenic rests (persistent metanephric blastema). Epidemiology Nephrogenic rest are found incidentally in 1% of infants. Pathology Nephrogenic rests are foci of metanephric blastema that persist beyond 36 ...
Article

Nephrocalcinosis

Nephrocalcinosis, previous known as Anderson-Carr kidney or Albright's calcinosis, refers to the deposition of calcium salts in the parenchyma of the kidney. It is divided into several types, with differing aetiologies, based on the distribution: medullary nephrocalcinosis: 95% cortical nephro...
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...
Article

Nephrostomy

Nephrostomy is a common urologic or interventional radiology procedure in which a tube/catheter is introduced into the renal collecting system (usually the renal pelvis). Nephrostomies can either be "open" nephrostomy: after a urological surgical procedure, such as a UPJ stone removal these t...
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

Neuroblastoma

Neuroblastomas are tumours of neuroblastic origin corresponding to the most common extracranial solid childhood malignancies and the third commonest childhood tumours after leukaemia and brain malignancies. It accounts for ~15% of childhood cancer deaths. Epidemiology The tumours typically occ...
Article

Neuroblastoma (staging)

There are two methods of neuroblastoma staging, one that is based on post-operative patients (INSS) and one developed for pre-treatment patients (INRGSS). Staging International Neuroblastoma Staging System (INSS) This staging system is for post-operative patients and mainly for prognosis 1: ...
Article

Neuroblastoma vs Wilms tumour

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. Neuroblastoma calcification very common: 90% encases vascular structu...
Article

Neurocristopathy syndromes

Neurocristopathy syndromes encompasses a group of conditions united by abnormal migration, differentiation, division or survival of neural crest cells 1. Examples include: Waardenburg-Shah syndrome Haddad syndrome MEN IIa neurofibromatosis type I (NF1) Sturge-Weber syndrome Bamforth-Lazar...
Article

Neurogenic bladder

Neurogenic bladder is a term applied to a dysfunctional urinary bladder that results from an injury to the central or peripheral nerves that control and regulate urination. Injury to the brain, brainstem, spinal cord or peripheral nerves from various causes including infection, trauma, malignanc...
Article

Non-seminomatous germ cell tumours

Non-seminomatous germ cell tumours (NSGCT) is one of the main groups of germ cell tumours (the other being seminoma). Although they are made up of distinct histological entities, in general, they have similar radiographic appearances. They can, however, be found widely in the body, with variable...
Article

Normal genitourinary tract imaging examples

This article serves as a resource for access to normal examples of imaging studies of the genitourinary tract.  Kidneys Plain radiograph KUB: example 1 abdominal x-ray: example 1 IVU IVU: example 1 Ultrasound renal ultrasound: example 1 renal ultrasound: example 2 renal ultrasound: exa...

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