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.

692 results found
Article

2014 WHO classification of endometrial stromal tumours

Endometrial stromal tumours (EST) constitute <2% of all uterine tumours and <10% of uterine mesenchymal neoplasms 1.  Over the past four decades, EST classification has gone through various modifications starting from the earliest study by Norris and Taylor 2. This was primarily due to th...
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AAST kidney injury scale

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

Abnormal renal rotation (renal malrotation) refers to an anatomical variation in the position of the kidneys, in particular to anomalous orientation of the renal hilum. It may occur unilaterally or bilaterally. It is almost always an asymptomatic incidental finding.  Epidemiology Malrotation i...
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Abscess

Abscesses are focal confined collections of suppurative inflammatory material and can be thought of as having three components 1: central core comprised of necrotic inflammatory cells and local tissue peripheral halo of viable neutrophils surrounded by a 'capsule' with dilated blood vessels a...
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Accessory renal artery

Accessory renal arteries are a common variant and are present in ~25% (range 20-30%) of the population. Sometimes, the term extrarenal artery may be used 2 with a further subclassification of: aberrant renal artery: supplying the superior and/or inferior pole of the kidney accessory renal art...
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Acquired cystic kidney disease

Acquired cystic kidney disease (ACKD) is a condition that occurs in patients with end-stage kidney disease (ESKD), especially when on dialysis treatment, and who do not have a history of other cystic renal disease.  Epidemiology Its incidence increases with the amount of time a patient is azot...
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Acute idiopathic scrotal oedema

Acute idiopathic scrotal oedema (AISE) is a self-limiting condition characterised by marked oedema of the skin and dartos fascia without involvement of the deeper layers, testes, or epidydimis. It is an important condition to recognise in order to avoid unnecessary surgical exploration. Epidemi...
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Acute pyelonephritis

Acute pyelonephritis remains common and continues to have significant morbidity in certain groups of patients. Epidemiology The incidence of acute pyelonephritis parallels that of lower urinary tract infections: approximately five times more common in females with a sharp increase following pu...
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Adenocarcinoma of the bladder

Adenocarcinoma of the bladder is rare, and accounts for only ~1% of all bladder cancers (90% are transitional cell carcinomas). Pathology Metaplasia of urinary bladder induced by chronic irritation or infection can lead to adenocarcinoma. Pathological types of adenocarcinoma of urinary bladder...
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Adenomatoid tumours of the scrotum

Adenomatoid tumours of the scrotum are benign, solid extra testicular lesions that can originate from the epididymis, tunica vaginalis, or spermatic cord (90% derived from the funiculus). Epidemiology They are the most common extra testicular neoplasm, and most common tumour of the epididymis,...
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Adrenal adenoma

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...
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Adrenal calcification

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

An adrenal collision tumour or collision tumour of the adrenal gland is an uncommon tumour of the adrenal gland, where two histologically distinct tumours abut each other or are in close proximity. Pathology Collision tumours have been reported in nearly every organ, for example collision tumo...
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Adrenal cortical carcinoma

Primary adrenal cortical carcinoma is a highly malignant but rare neoplasm. It may present as a hormonally active or inactive tumour.  Epidemiology Although men and women are affected equally, functioning tumours are more common in females, who are also more likely to have an associated endocr...
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Adrenal gland

The adrenal (suprarenal) glands lie anteromedial to the kidneys. They are paired organs of the endocrine system but are quite asymmetric in shape.  Gross anatomy Each gland is enclosed in the perirenal fascia and each have a body and two limbs - medial and lateral. However, the right adrenal g...
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Adrenal gland trauma

Adrenal gland trauma most commonly results from blunt force trauma. Epidemiology Adrenal gland trauma is present on 1-2% of CT imaging in blunt trauma although the occurrence is thought to be much higher as injury has been demonstrated at 28% in one autopsy series 1-4.  The right adrenal glan...
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Adrenal haemangioma

Adrenal haemangiomas are rare benign tumours that are usually incidentally identified (one example of an adrenal incidentaloma). Its significance mainly relates to the difficulty in differentiation from other malignant lesions.  Epidemiology Although these can be found at any age, they are mos...
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Adrenal haemorrhage

Adrenal haemorrhage can result from a variety of causes (traumatic as well as non-traumatic). When unilateral, it is often clinically silent. In contrast, bilateral adrenal haemorrhage can lead to catastrophic adrenal insufficiency. Clinical presentation The large majority of patients with uni...
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Adrenal hyperplasia

Adrenal hyperplasia refers to nonmalignant growth (enlargement) of the adrenal glands and is a rare cause of ACTH-independent Cushing syndrome with unilateral adrenal cortical adenomas being the commonest. 20% of Conn syndrome cases are secondary to adrenal hyperplasia.  In diffuse hyperplasia, ...
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Adrenal lesions

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. Radiology plays a significant role in differentiation. Cross sectional imaging is the mainstay of imaging for identifyin...
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Adrenal metastases

Adrenal metastases are the most common malignant lesions involving the adrenal gland. Metastases are usually bilateral but may also be unilateral. When unilateral involvement is thought to be more prevalent on the left side (ratio of 1.5:1). Epidemiology They are thought to be present in up to...
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Adrenal myelolipoma

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. Epidemiology Rare tumours with estimated ...
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Adrenal pseudocyst

Adrenal pseudocysts account for approximately 39% of adrenal cysts, and are more likely than simple adrenal cysts to be symptomatic. Pseudocysts do not have an epithelial lining and typically arise after an episode of adrenal haemorrhage. Radiographic features Adrenal pseudocysts appear as a ...
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Adrenal vein sampling

Adrenal vein sampling (AVS) is a procedure used to confirm autonomous hormone production, if it is unilateral or bilateral, to guide further treatment. Indication AVS is commonly performed in primary aldosteronism, being indicated to identify aldosterone-secreting adenomas and to differentiate...
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Adrenal washout

Adrenal washout can be calculated using the density value of an adrenal mass on non-enhanced, portal venous phase and 15 minutes delayed CT-scans. It is primarily used to diagnose adrenal adenoma. absolute washout [(HUportal venous phase) - (HUdelayed)] / [(HUportal venous phase) - (HUnon-enha...
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Adrenocorticotropin independent macronodular adrenocortical hyperplasia

Adrenocorticotropin independent macronodular adrenocortical hyperplasia (AIMAH) is considered a rare form of macronodular adrenal hyperplasia. It is an uncommon cause of primary adrenal hypercortisolism. Clinical presentation Patients with AIMAH tend to present 10 years on average than the tim...
Article

Adult cystic renal disease

Adult cystic renal disease comprises multiple distinct hereditary and non-hereditary disease processes.  Pathology Aetiology Hereditary adult polycystic kidney disease (APCKD), a.k.a. autosomal dominant polycystic kidney disease (ADPCKD) medullary cystic kidney disease von Hippel-Lindau di...
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Aggressive angiomyxoma

Aggressive angiomyxomas are rare pelvic tumours that arise in the pelvis and typically cross the the levator ani muscles. Despite its name, it is essentially a benign tumour and the term "aggressive" is given due to predilection for local recurrence. Only rarely does it metastasise.   ...
Article

Alport syndrome

Alport syndrome is an X-linked recessive disease characterised by:  haematuria sensory neural hearing loss: typically high frequency 2 ocular abnormalities  anterior lenticonus: most common ocular abnormality; may result in cataracts perimacular pigmentary changes flecks around the fovea 2...
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Anatomy curriculum

The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge. General anatomy Neuroanatomy Head and neck anatomy Thoracic anatomy Abdominal and pelvic anatomy Spinal anatomy Lower limb anatomy Upper limb anato...
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Androgen insensitivity syndrome

Androgen insensitivity syndrome (AIS), also known as the testicular feminisation syndrome, results from end-organ resistance to androgens, particularly testosterone. AIS may be complete or incomplete with variable imaging findings.  Epidemiology The incidence may vary dependent on whether it i...
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Angiomyofibroblastoma like tumour of scrotum

Angiomyofibroblastoma like tumour of scrotum is a rare well-defined slow growing mesenchymal extratesticular nonepididymal tumour which rarely seen in perineum and scrotum of older male patients. A similar tumour can occur in the vulval region in females. Epidemiology  In males, they seen in m...
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Antegrade ureteric stent

Antegrade ureteric stents are performed under fluoroscopic guidance, typically by an interventional radiologist or urologist. It is performed via percutaneous access from the kidney. It is usually performed using the access from a prior percutaneous nephrostomy, a so-called 2-step procedure, alt...
Article

Anterior pararenal space

The anterior pararenal space is the portion of the retroperitoneum that lies between the posterior surface of the parietal peritoneum and the anterior reflection of the perirenal fascia. Gross anatomy It contains the duodenum, pancreas and retroperitoneal segments of the ascending and descendi...
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Antopol-Goldman lesion

Antopol-Goldman lesions are very rare presentations of subepithelial haemorrhage in the renal pelvis, presenting as discrete mass-like haematomas. Pathology The cause of these lesions is uncertain, although non-steroidal anti-inflammatory drug (NSAID) overuse, trauma, and amyloidosis have been...
Article

Artificial urethral sphincter

Artificial urinary sphincters replace the function of the natural urinary sphincter in patients with sphincter damage or neurologic disease, most commonly as a result surgery for prostate cancer. They are sometimes used in combination with a bladder neck stent. Components A typical design inc...
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Asbestos related diseases

Asbestos related disease, in particular affecting the lung, comprise of a broad spectrum of entities related to the inhalational exposure to asbestos fibres. They can be divided into benign and malignant changes 1-3. Benign pleural and parenchymal lung disease asbestos related benign pleural d...
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Atypical small acinar proliferation

Atypical small acinar proliferations (ASAP) are premalignant lesions of the prostate, which can be found in as many as 5% of prostate biopsies. They are suspicious glands without adequate histologic atypia to establish a definitive diagnosis of prostate cancer. Some studies showed that there is ...
Article

Aubergine sign

The aubergine sign (also known as egg-plant sign or deformity) is a clinical sign of a fractured penis. Haemorrhage beyond the tunica albuginea produces swelling and bruising of the penis simulating the appearance of an aubergine.  
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Autosomal dominant polycystic kidney disease

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.  Epidemiology Autosomal dominant polycystic kidney disease is one of the ...
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Autosomal recessive polycystic kidney disease

Autosomal recessive polycystic kidney disease (ARPKD) is one of many paediatric cystic renal diseases. On imaging, it usually presents on ultrasound with enlarged echogenic kidneys with multiple small cysts. Liver involvement with coarse echotexture, biliary tract cystic changes, and portal hyp...
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Avascular plane of Brodel

The avascular plane of Brodel is the section of renal parenchyma in the posterior kidney that is relatively avascular. The reason for its relative avascularity is that it represents the plane where the renal artery branches meet. It is located just posterior to the lateral convex border of the ...
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Azoospermia

Azoospermia refers to complete absence of sperm in the semen. It accounts for 5-10% of male infertility 1. Pathology 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 ...
Article

Balkan nephropathy

Balkan nephropathy refers to a degenerative interstitial nephropathy endemic to the Balkan states, which is associated with a very high rate of transitional cell carcinomas of the renal pelvis and upper ureter.  Epidemiology The condition is largely restricted to the villages along the Danube ...
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Balloon on a string sign - IVU

In renal imaging, the balloon on a string sign refers to the appearance on IVU in ureteropelvic junction obstruction. It is seen due to the high and eccentric point of exit of ureter from a dilated renal pelvis. 
Article

Bardet-Biedl syndrome

Bardet-Biedl syndrome (BBS) previously known as the Laurence-Moon-Bardet-Biedl syndrome (LMBBS) is a rare autosomal recessive hereditary condition. Clinical features The clinical spectrum includes retinal anomalies: similar to that of retinitis pigmentosa mental retardation renal structural...
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Bartter syndrome

Bartter syndrome is a rare inherited renal disorder. Pathology Bartter syndrome is characterised by hyperplasia of the juxtaglomerular cells along with: hypokalemia metabolic alkalosis hypotension or normotension  elevated plasma renin  elevate aldosterone antenatal polyhydramnios Class...
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Batson venous plexus

Batson venous plexus (Batson veins) is a network of veins with no valves that connect deep pelvic veins draining the bladder, prostate and rectum to the internal vertebral venous plexus 1. These veins are important because they are believed to provide a route for spread of pelvic cancer metastas...
Article

Bear paw sign

The bear paw sign is seen in xanthogranulomatous pyelonephritis and refers to the cross-sectional appearance of the kidney which is said to resemble the paw of a bear. The renal pelvis is contracted whereas the calyces are dilated, mimicking the toe-pads of the paw.
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Behçet disease

Behçet disease is a multi-systemic and chronic inflammatory vasculitis of unknown aetiology. Epidemiology 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...
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Bell clapper deformity

A bell clapper deformity is a predisposing factor in testicular torsion in which the tunica vaginalis joins high on the spermatic cord, leaving the testis free to rotate. Bell clapper deformity predisposes to intravaginal torsion of the testis.
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Benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) 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 increase in the number of epithelial a...
Article

Bifid ureter

A bifid ureter, or ureter fissus, is an example of incomplete duplication of a duplex collecting system.  Epidemiology Present in ~5% (range 1-10%) of the population 1-2.  Gross anatomy A bifid ureter is formed when there is a duplex kidney (separate pelvicalyceal collecting systems) drain i...
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Bilateral adrenal enlargement

The differential for bilaterally enlarged adrenal glands is relatively limited: adrenal hyperplasia micronodular adrenal hyperplasia macronodular adrenal hyperplasia adrenocorticotropin (ACTH)-independent macronodular adrenocortical hyperplasia (AIMAH) 2 adrenal metastases adrenal haemorrh...
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Bilateral renal enlargement

Bilateral renal enlargement can arise from a number of causes which include 1: diabetic nephropathy (common) renal involvement with lymphoma adult dominant polycystic kidneys (ADPKD) von-Hippel-Lindau disease nephroblastomatosis tuberous sclerosis bilateral renal cell carcinoma
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Bilateral testicular lesions

Bilateral testicular lesions have a relatively limited 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 the chemoptherapy inabil...
Article

Bilobed testis

Bilobed testis, also known as incomplete unilateral polyorchidism, is a very rare variant in children. Pathology The exact aetiology is unknown but is thought be a form of incomplete polyorchidism. It has been proposed that bilobed testis results from incomplete division of the urogenital ridg...
Article

Birt-Hogg-Dubé syndrome

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) cutaneous manifestations (angiofibromas, perifoll...
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Bladder and ureteric tuberculosis

Bladder and ureteric tuberculosis (TB) refers to infection of ureters and urinary bladder with M. tuberculosis. Radiographic features Ureteric TB IVP characteristic beaded appearance due to alternate areas of strictures and dilatation (chronic state) CT acute: ureteral wall thickening​ ​c...
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Bladder calcification (mnemonic)

A simple mnemonic to recall the common causes of bladder calcification is: SCRITT Mnemonic S: schistosomiasis C: cytotoxic: see radiation and chemotherapy induced cystitis R: radiation: see radiation and chemotherapy induced cystitis I: interstitial cystitis T: tuberculosis T: transition...
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Bladder calculus

Bladder calculi occur either from migrated renal calculi or urinary stasis. Bladder calculi can be divided into primary and secondary stones: primary: stones form de novo in the bladder secondary: stones are either from renal calculi which have migrated down into the bladder, or from concretio...
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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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Bladder inflammatory pseudotumour

A bladder inflammatory pseudotumour is a nonneoplastic proliferation of cells. Epidemiology This entity is more common in adults, with a mean age at diagnosis of 38 years.  Clinical presentation Patients present most commonly with an ulcerating bleeding mass, hematuria, and voiding symptoms....
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Bladder outlet obstruction

Bladder outlet obstruction (BOO) can come 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 eitolgies b...
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Bladder wall calcification (mnemonic)

A mnemonic for the causes of bladder wall calcification is: CREST Mnemonic C: cystitis post radiation therapy / chemotherapy / chronic infection R: radiation E: eosinophilic cystitis S: schistosomiasis T: tuberculosis
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Bladder wall thickening (differential)

Differential diagnosis for bladder wall thickening depends on whether the bladder is adequately distended. The bladder wall may be thickened if: >3 mm when distended >5 mm when nondistended If the bladder is not distended, then it is difficult to exclude artifactual thickening from a co...
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Boari bladder flap

A Boari bladder flap is one of the options for ureteric reimplantation when the diseased ureteric segment is long (e.g. more than 5 cm). It is useful in the management of lower ureteric strictures and can be performed as either an open or laparoscopic procedure. It involves tubularisation of a f...
Article

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...
Article

Bouquet of flowers appearance

A bouquet of flowers appearance is a description given to the appearances of medullary sponge kidney on a traditional intravenous pyelogram (IVP) study. The ectatic distal collecting ducts contain the microcalcification typical of the disease. This is also known as a 'bunch of grapes' appearance...
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Brachytherapy

Brachytherapy, also known as sealed source radiotherapy or endocurietherapy, is a form of radiotherapy where a radioactive source is placed, under the guidance of imaging, within or next to the area requiring treatment. Brachytherapy is commonly used to treat localised prostate cancer, breast c...
Article

Branchio-oto-renal dysplasia

Branchio-oto-renal (BOR) dysplasia is a rare syndromic disorder characterised by: otic malformations can involve the outer, middle, and inner ear associated with conductive, sensorineural, or mixed hearing impairment preauricular pits branchial fistulae and branchial cleft cysts renal malfo...
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

Burned out testis tumour

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. Pathology Retrope...
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Calciphylaxis

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. ...
Article

Calyceal crescent sign

The calyceal crescent sign (Dunbar's crescents) refers to the early 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 associated enlarged calyces.  ...
Article

Calyceal microlithiasis

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.  Clinical presentation The patient may be asymptom...
Article

Cannonball metastases

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 appear...
Article

Carcinogens

Carcinogens are substances known to cause cancer. They include: Brain vinyl chloride Nasopharynx / nasal passage nickel wood dust chromium Thyroid ionising radiation (not technically a substance) Skin arsenic coal tars polyaromatic hydrocarbons (PAH) Lungs arsenic asbestos chloro...
Article

Causes of urinary bladder diverticulae

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

Cervical cancer staging

Staging of cervical cancer can either be based on the TNM or FIGO system. Revised FIGO staging of cervical carcinoma 2009 8 stage 0: cervical intraepithelial neoplasia (HSIL or CIN III)  stage I: confined to cervix stage Ia: invasive carcinoma only diagnosed by microscopy. Ia1: stromal inva...
Article

Cervical intraepithelial neoplasia

Cervical intraepithelial neoplasia (CIN) (also known as cervical dysplasia) is the potentailly premalignant stage in the dysplastic changes in the squamous epithelium of the cervix.  Grading of CIN is based on the degree of dysplasia seen in a sample of cervical tissue: CIN I similar to condy...
Article

Cesarean section scar diverticulum

Cesarean section scar diverticulums are a defect in the lower uterine cavity at the site of the cesarean section scar.  Clinical presentation mostly asymptomatic postmenstrual spotting in a study was found to be the only finding in patients with bleeding disturbances Radiographic features ...
Article

Christmas inspired signs

There are many signs in radiology that are related to Christmas: snowcap sign in avascular necrosis snowman sign in total anomalous pulmonary venous return in pituitary macroadenomas snowstorm appearance in complete hydatidiform and testicular microlithiasis holly leaf sign in calcified pl...
Article

Chromaffin cells

Chromaffin cells are neuroendocrine cells found predominantly in the medulla of the adrenal gland. They are also found in other ganglia of the sympathetic nervous system and are derived from the embryonic neural crest. Embryology They arise in the fifth week of fetal development when neuroblas...
Article

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...
Article

Chronic periaortitis

Chronic periaortitis is an inflammatory condition which typically involves the infrarenal portion of the abdominal aorta. It is a rare disease usually occuring in middle-aged men. It has various clinical presentations: idiopathic retroperitoneal fibrosis (IRF) perianeurysmal retroperitoneal f...
Article

Chronic primary adrenal insufficiency

Chronic primary adrenal insufficiency has a number of causes. Primary adrenal insufficiency is termed Addison disease. Pathology Causes idiopathic atrophy: autoimmune disease tuberculosis: 25% calcify fungal disease histioplasmosis blastomycosis coccidioidomycosis sarcoidosis bilateral...
Article

Chronic pyelonephritis

Chronic pyelonephritis is form of pyelonephritis where there are longstanding sequelae of renal infection. At the time of writing there is still no definitive consensus at to whether the condition represents an active chronic infection, arises from multiple recurrent infections, or represents st...
Article

Circumaortic left renal vein

Circumaortic left renal vein, also known as circumaortic renal collar is an anomaly of left renal vein when a supernumerary or accessory left renal vein passes posterior to the aorta, apart from the normal renal vein passing anterior to the aorta. This anomaly is potentially hazardous, if unreco...
Article

Circumcaval ureter

A circumcaval ureter, or retrocaval ureter, is a developmental anomaly of the inferior vena cava (IVC). Unfortunately both terms suggest that the ureter is at fault, whereas in reality it is the IVC. They are of two types: high loop low loop Clinical presentation Many patients with this anom...
Article

Citrate peak

Citrate is a compound examined in MR spectroscopy in the setting of possible prostate carcinoma. Citrate resonates at 2.6 ppm and is decreased in prostate cancer.  For more information go to: MR spectroscopy in prostate cancer
Article

Claw sign

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 su...
Article

Clear cell sarcoma of the kidney

Clear cell sarcoma (CCS) of the kidney are a rare mesenchymal tumour that account for ~5% of primary renal neoplasms in paediatric population 1.  Epidemiology CCS is the second most common primary malignant renal neoplasm after Wilms tumour, with an annual incidence of 20 cases in the United S...

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