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 continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
1,108 results found
Article
Unilateral testicular lesions
The differential diagnosis for unilateral testicular lesions is wide-ranging.
Neoplastic
Common
seminoma (40-50% of testicular malignancies)
non-seminomatous germ cell tumors:
testicular teratoma
testicular epidermoid (teratoma with ectodermal elements only)
testicular choriocarcinoma
t...
Article
Renal angiomyolipoma
Renal angiomyolipomas (AML) are a type of benign renal neoplasm encountered both sporadically and as part of a phakomatosis, most commonly tuberous sclerosis. They are considered one of a number of tumors with perivascular epithelioid cellular differentiation (PEComas) and are composed of vascul...
Article
Fibromuscular dysplasia
Fibromuscular dysplasia (FMD) is a heterogeneous group of vascular lesions characterized by idiopathic, non-inflammatory, and non-atherosclerotic angiopathy of small and medium-sized arteries.
Epidemiology
The prevalence is unknown 7. It is most common in young women with a female to male rati...
Article
Pheochromocytoma
Pheochromocytomas are an uncommon tumor of the adrenal gland, with characteristic clinical, and to a lesser degree, imaging features. The tumors are said to follow a 10% rule:
~10% are extra-adrenal
~10% are bilateral
~10% are malignant
~10% are found in children
~10% are not associated wit...
Article
Malakoplakia
Malakoplakia is a rare chronic granulomatous inflammatory disease that can affect any part of the body but most frequently involves the mucosal surface of the urinary bladder, causing one or more soft yellowish plaques.
Epidemiology
Risk factors include chronic disease and immunosuppression, s...
Article
Hairy kidney sign (Erdheim-Chester disease)
The hairy kidney sign refers to the soft tissue ring of perirenal infiltration seen on cross-sectional imaging studies in Erdheim-Chester disease and is considered to be pathognomonic of this disease. The ‘‘hairy’’ description refers to the associated thickening of the bridging perirenal septa (...
Article
Transitional cell carcinoma (ureter)
Transitional cell carcinoma (TCC) of the ureter, also called urothelial cell carcinoma (UCC) of the ureter, is uncommon compared to similar tumors elsewhere along the urinary tract but is nonetheless the most common primary tumor of the ureter.
This article concerns itself with transitional cel...
Article
von Hippel-Lindau disease (mnemonic)
Features of von Hippel-Lindau disease can be remembered by the mnemonic:
HIPPEL
Mnemonic:
H: hemangioblastoma of CNS
I: increased risk of renal cell cancer
P: pheochromocytoma
P: pancreatic lesions (cyst, cystadenoma, cystadenocarcinoma, neuro-endocrine tumors)
E: eye and ear dysfunction ...
Article
Tuberous sclerosis (diagnostic criteria)
The tuberous sclerosis diagnostic criteria have been developed to aid the diagnosis of tuberous sclerosis and have been updated in 2012 by the International Tuberous Sclerosis Complex Consensus Group (at time of writing - 2019) 1.
Diagnosis
Genetic criteria
The identification of either a TSC...
Article
Metallic ureteric stent
Metallic ureteric stents are a type of ureteric stent developed to offer improved symptomatic relief of obstruction when compared to polymeric (polyurethane) stents. They are often used in patients with chronic malignant ureteric obstructions who require placement of long-term ureteral stents to...
Article
Germ cell tumor (classification)
Germ cell tumors are classified into two broad groups: seminoma and non-seminomatous germ cell tumors (NSGCT). The later is then divided further according to histology:
seminoma
non-seminomatous germ cell tumors (NSGCT)
embryonal cell carcinoma
choriocarcinoma
yolk sac tumor
teratoma
mixe...
Article
Prostatic abscess
Prostatic abscesses are a rare complication of prostatitis.
Epidemiology
Prostatic abscesses have become relatively uncommon due to the increased use of antibiotic therapy in patients with prostatitis. It tends to affect diabetic and immunosuppressed patients. Most patients affected are aroun...
Article
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 two-step procedure, a...
Article
Transition zone (disambiguation)
Transition zone may refer to the:
transition zone of a nerve
transition zone of the lens 2
zone of transition of a bone lesion
transition zone (TZ) of the prostate
transition zone of a bowel obstruction 3
transition zone of Hirschsprung disease 4
It is important to note that the correct t...
Article
Salt and pepper sign (disambiguation)
The salt and pepper sign is used to refer to a speckled appearance of tissue on imaging. It is used in many contexts, but most commonly for the appearance of certain lesions on MRI, especially paragangliomas.
salt and pepper noise (MRI artifact) 9
salt and pepper sign (ARPCKD) 8
salt and pepp...
Article
Hypospadias
Hypospadias refers to a type of congenital malformation affecting the male external genitalia.
Epidemiology
The estimated prevalence is ~2 (range 0.2-4.1) per 1000 live births.
Pathology
The urethral meatus is abnormally positioned proximally and ventrally to its normal position.
It is thou...
Article
Neonatal hydronephrosis
Neonatal hydronephrosis is most commonly diagnosed antenatally as fetal pylectasis, and in the majority of cases is due to pelviureteric junction (PUJ) obstruction.
Pathology
Etiology
pelviureteric junction (PUJ) obstruction (50% of cases 1,6)
vesicoureteric reflux (~20% of cases 5)
poste...
Article
Paintbrush appearance
A paintbrush appearance describes the streaky appearances of dilated contrast filled tubules within the renal medulla on IVP or CT-IVU. This appearance is characteristic for medullary sponge kidneys.
A similar appearance is also seen in the renal tubular ectasia; though less pronounced.
See al...
Article
Growing teratoma syndrome
Growing teratoma syndrome is a rare complication after treatment for metastatic (or in the case of intracranial disease, primary) non-seminomatous germ cell tumors (NSGCT).
It was first described in the pediatric population with treated germ cell neoplasms, and represents enlarging masses at th...
Article
Prostate cancer
Prostate cancer ranks as the most common primary malignant tumor in men and the second most common cause of cancer-related deaths in men. Prostatic adenocarcinoma is by far the most common histological type and is the primary focus of this article.
Terminology
The aim of prostate MRI is to det...
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