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.
1,463 results found
Article
AAST spleen injury scale
The American Association for the Surgery of Trauma (AAST) splenic injury scale, revised in 2018, is the most widely used grading system for splenic trauma.
The 2018 update incorporates "vascular injury" (i.e. pseudoaneurysm, arteriovenous fistula) into the imaging criteria for visceral injury 4...
Article
Rectal cancer response assessment
Assessment of rectal cancer response to therapy, which may be chemotherapy, radiotherapy, or a combination, relies on the synthesis of clinical, endoscopic and radiologic evaluation.
The purpose of neoadjuvant therapy is to downstage the tumor, to facilitate surgical resection, and reduce loca...
Article
Emphysematous pancreatitis
Emphysematous pancreatitis is an unusual complication of acute pancreatitis caused by necrotizing infection of the pancreas. It is associated with gas-forming bacteria and characterized by the presence of gas within or around the pancreas 1.
Pathology
Infection with gas-forming bacteria such ...
Article
Anal cancer (staging)
The TNM staging of anal cancer is as follows:
Primary tumor (T)
TX: primary tumor cannot be assessed
T0: no evidence of primary tumor
Tis: carcinoma in situ (Bowen disease, high-grade squamous intraepithelial lesion [HSIL], anal intraepithelial neoplasia II-III (AIN II-III)
T1: tumor 2 cm o...
Article
Extrapulmonary tuberculosis
Extrapulmonary tuberculosis (TB) refers to the hematogenous spread of Mycobacterium tuberculosis.
Pathology
Extrapulmonary tuberculosis can occur as a primary form of the disease, i.e. direct infection of an extrapulmonary organ without the presence of primary pulmonary tuberculosis or it can ...
Article
Irritable bowel syndrome
Irritable bowel syndrome (IBS) is the commonest of the functional gastrointestinal disorders (FGIDs). Its key presenting features are recurrent abdominal pain and change in bowel habit (diarrhea and/or constipation), which may be severe, such that for an individual, there may be a marked negativ...
Article
Anal atresia
Anal atresia, or imperforate anus, refers to a spectrum of anorectal abnormalities ranging from a membranous separation to complete absence of the anus.
Epidemiology
The estimated incidence is 1 in 5000 live births.
Associations
There are frequent associations with other congenital abnormali...
Article
Small bowel mesentery internal hernia
Small bowel mesentery internal hernias (alternative plural: herniae) are a form of internal bowel herniation involving protrusions of viscera through defects in the peritoneum or bowel mesentery.
Epidemiology
This type of internal herniation is more often seen in neonates than in adults ref.
...
Article
Chemical shift artifact
Chemical shift artifact or misregistration is a type of MRI artifact. It is a common finding on some MRI sequences and used in magnetic resonance spectroscopy (MRS). This artifact occurs in the frequency-encoding direction and is due to spatial misregistration of fat and water molecules.
Chemi...
Article
Crohn disease
Crohn disease, also known as regional enteritis, is an idiopathic inflammatory bowel disease characterized by widespread discontinuous gastrointestinal tract inflammation. The terminal ileum and proximal colon are most often affected. Extraintestinal disease is common.
Epidemiology
The diagnos...
Article
Ascites
Ascites (hydroperitoneum is a rare synonym) is defined as an abnormal amount of intraperitoneal fluid.
Terminology
Ascites (plural is the same word) tends to be reserved for relatively sizable amounts of peritoneal fluid. The amount has not been defined formally. It is noted physiologically, h...
Article
Gastropericardial fistula
Gastropericardial fistulas are rare abnormal communications between the stomach and the pericardial sac. This is a life-threatening condition that can lead to impaired cardiac function, sepsis and eventually death.
Clinical presentation
Patients with gastropericardial fistula may present with ...
Article
Cystic lesions of the pancreas (differential)
The differential for cystic lesions of the pancreas includes:
unilocular
pancreatic pseudocyst
intraductal papillary mucinous neoplasm (IPMN)
serous cystadenoma uncommonly uni/macrolocular
simple pancreatic cyst
cystic neuroendocrine tumor of the pancreas
diffuse pancreatic cysts
pancrea...
Article
Rectoanal intussusception
Rectoanal intussusception refers to the telescoping or infolding of the rectal wall within the rectum itself, or into the anal canal, or externally, during defecation.
Terminology
Rectoanal intussusception is also termed internal intussusception and internal procidentia1 .
Epidemiology
Recto...
Article
Intraductal papillary mucinous neoplasm
Intraductal papillary mucinous neoplasms or tumors (IPMNs or IMPTs) are epithelial pancreatic cystic tumors of mucin-producing cells that arise from the pancreatic ducts. They are most commonly seen in elderly patients.
On imaging, particularly MRCP, they are characterized by single or multipl...
Article
Intestinal transplant
Intestinal transplantation is a surgical treatment for intestinal failure. It is one of the most rarely performed transplant procedures performed, exclusively involving the transplantation of donor small bowel to a recipient, with an ileostomy formation.
Due to the high risk of complications w...
Article
Benign post-traumatic pseudopneumoperitoneum
Benign post-traumatic pseudopneumoperitoneum is the presence of ectopic gas typically between the 5th-10th intercostal spaces after high-energy trauma in the absence of other causes of pseudopneumoperitoneum such as pneumomediastinum 9.
Epidemiology
Occurs with an incidence of 5% post-trauma...
Article
Barium sulfate contrast medium
Barium sulfate (BaSO4), often just called barium in radiology parlance, is an ionic salt of barium (Ba), a metallic chemical element with atomic number 56. Barium sulfate forms the basis for a range of contrast media used in fluoroscopic examinations of the gastrointestinal tract. Unlike barium ...
Article
Appendix
The appendix or vermiform appendix (plural: appendices) is a blind muscular tube arising from the cecum, the first part of the large bowel.
Gross anatomy
The appendix arises from the posteromedial surface of the cecum, approximately 2-3 cm inferior to the ileocecal valve, where the three longi...
Article
Rectal cancer (staging)
Staging of rectal cancer uses the TNM staging system and strongly predicts the success, and rate, of local recurrence following rectal cancer resection. MRI is the modality of choice for the staging of rectal cancer, to guide surgical and non-surgical management options. MRI is used at diagnosis...