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.

65 results found
Article

Decreased duodenal folds

Decreased duodenal folds may be seen on imaging modalities, particularly MR enterography, and differential diagnoses include: scleroderma - usually with duodenal dilatation celiac disease - particularly involves the distal duodenum and jejunum Crohn disease  cystic fibrosis amyloidosis
Article

Nontoxic megacolon

Nontoxic megacolon refers to colonic dilatation of more than 6 cm in an adult without mural abnormality. This is in contrast to toxic megacolon, an acute complication accompanied by mural abnormalities such as thickening, loss of haustral folds, pneumatosis or free gas. The differential diagnos...
Article

Bowel wall fat deposition

Bowel wall fat deposition refers to the infiltration of the submucosa with fat and usually occurs in chronic processes such as inflammatory bowel disease, causing characteristic fat halo sign on CT images.  Other differential diagnoses include: normal variant - particularly in obese patients w...
Article

Bowel wall calcification

Bowel wall calcification is not common and can occur secondary to various mechanisms due to benign, premalignant, or malignant lesions. The differential diagnoses include:  mucinous adenocarcinoma gastrointestinal stromal tumor (GIST) metastatic calcification - due to renal failure hemangio...
Article

Hypervascular splenic lesions

Hypervascular splenic lesions are findings that enhance more or similarly to the background splenic parenchyma on late arterial phase, on contrast-enhanced CT or MRI. Vascular mycotic aneurysm Neoplastic splenic hemangioma 2 most common primary benign neoplasm of the spleen second most com...
Article

Hypervascular pancreatic lesions

Hypervascular pancreatic lesions are findings that enhance more or similarly to the background pancreatic parenchyma in the late arterial phase, on contrast-enhanced CT or MRI. Anatomical variants intrapancreatic accessory spleen: should not be overdiagnosed as a malignant tumor  Vascular ano...
Article

Intrapancreatic gas

The presence of gas in the pancreatic gland and/or the pancreatic ducts is an uncommon finding. Pathology Etiology Causes of gas in the pancreatic ducts altered function and/or anatomy of the sphincter of Oddi: causes duodenal-pancreatic duct reflux patulous pancreatic duct opening 2  papi...
Article

Cirrhotic liver nodules - differential

Differential diagnoses of cirrhotic liver nodules include regenerative liver nodules, dysplastic liver nodules, and hepatocellular carcinoma (HCC), all represent a spectrum of diseases ranging from non-neoplastic reparative process (regenerative) to nuclear atypia (dysplastic) to typical neoplas...
Article

Mass-forming chronic pancreatitis

Mass-forming chronic pancreatitis occurs in around 30% of cases of chronic pancreatitis, where a mass or a focal enlargement of the pancreas is usually seen on imaging. In many instances, it poses a challenge as the epidemiology and imaging appearances overlap those of pancreatic adenocarcinoma....
Article

Duodenal stricture

A duodenal stricture refers to a segment of narrowing involving the duodenum. They can occur from a range of benign infective - inflammatory to malignant etiology. They can contribute to gastric outlet obstruction. Pathology Etiology infective/inflammatory  duodenitis regional inflammation:...
Article

Disconnected pancreatic duct syndrome

Disconnected pancreatic duct syndrome, also referred only as disconnected pancreatic duct, refers to the symptoms and complications due to the complete discontinuity of the main pancreatic duct between segments of viable secreting pancreatic tissue and the duodenum, usually seen as a sequela of ...
Article

Retrorectal developmental cysts

Retrorectal developmental cysts are rare and mostly congenital benign lesions found in the retrorectal space:  spectrum of cystic teratomas retrorectal epidermoid cyst retrorectal dermoid cyst retrorectal teratoid cyst enteric cysts duplication cyst of the rectum tailgut duplication cyst ...
Article

Hepatosplenomegaly

Hepatosplenomegaly is simply the simultaneous presence of a pathologically-enlarged liver (hepatomegaly) and spleen (splenomegaly). Pathology Etiology Infection Many infections can produce a mild concurrent enlargement of the liver and spleen. This list is by no means exhaustive. viral EBV...
Article

Bowel wall thickening

Bowel wall thickening is a useful finding on imaging studies and has a number of different causes. Pathology The reason for bowel wall thickening depends on the underlying etiology but includes submucosal edema, hemorrhage, and neoplastic infiltration. Radiographic features In describing bow...
Article

Intestinal failure

Intestinal failure is when a patient's native bowel is unable to digest and absorb the food, electrolytes, and fluids needed for normal growth and development.  Clinical presentation This often includes intractable diarrhea, weight loss, dehydration, electrolyte imbalance, and malnutrition. P...
Article

Diffuse colonic nodularity (differential)

Diffuse colonic nodularity on barium enema or CT colonography has a range of possible etiologies: lymphoid hyperplasia (tend to be small and discrete) lymphoma (tend to be larger nodules and confluent) urticaria (closely spaced polygonal lesions, history is often helpful) pseudomembranous co...
Article

Megaesophagus

Megaesophagus or diffuse esophageal dilatation can be caused by a variety of conditions.  Pathology Etiology Some of the more common causes are given below 1-3: esophageal dysmotility achalasia Chagas disease scleroderma distal obstruction malignant stricture, e.g. esophageal cancer, ca...
Article

Spontaneous splenic rupture

Spontaneous splenic rupture (SSR) (also known as atraumatic splenic rupture) is rare, especially when compared to traumatic splenic rupture.  Pathology The pathogenesis of atraumatic splenic rupture is not well understood. Splenomegaly is present in almost all patients (~95%), although the rup...
Article

Malignant esophageal neoplasms

Malignant esophageal neoplasms are much more common than benign esophageal neoplasms, especially if the patient is symptomatic.  Pathology esophageal carcinoma (90%) esophageal squamous cell carcinoma (SCC) esophageal spindle cell carcinoma esophageal adenocarcinoma esophageal neuroendocri...
Article

Non-neoplastic solid lesions of the pancreas

Non-neoplastic solid lesions of the pancreas are conditions which may mimic pancreatic neoplasms on imaging. They include: focal pancreatitis autoimmune pancreatitis fatty infiltration-replacement intrapancreatic accessory spleen peripancreatic lymph node congenital anomalies prominent pa...
Article

Granular mucosal pattern of the esophagus (differential)

Granular mucosal pattern of the esophagus represents very fine nodularity of the esophageal mucosal surface. This finding is non-specific and may represent: reflux esophagitis (most common) Candida esophagitis glycogenic acanthosis Barrett esophagus superficial spreading esophageal carcinom...
Article

Enteritis

Enteritis (plural: enteritides) refers to inflammation of the small bowel. When associated with inflammation of the stomach, the term gastroenteritis is used which is usually caused by infection. Pathology Etiology infection infective enteritis eosinophilic enteritis ischemia inflammatory...
Article

Pancreatic atrophy

Pancreatic atrophy is non-specific and is common in elderly patients, although in younger patients it can be a hallmark of pathology. Most commonly it is associated with aging, obesity and end-stage chronic pancreatitis.  It occurs principally with fatty replacement of the pancreas (pancreatic ...
Article

Vertical-banded gastroplasty

Vertical-banded gastroplasty (VBG) is an older, purely restrictive procedure used to treat morbid obesity. Procedure It involves creating a small gastric pouch, based on the lesser curvature of the stomach (which is thicker and less resistant to stretching than the greater curvature), by using...
Article

Malignant vs benign gastric ulcer (barium)

Barium meal has been frequently used to differentiate malignant and benign gastric ulcers: Features suggesting benign gastric ulcer outpouching of ulcer crater beyond the gastric contour (exoluminal) smooth rounded and deep ulcer crater smooth ulcer mound smooth gastric folds that reach the...
Article

Right iliac fossa mass (differential)

Right iliac fossa mass is a common clinical presentation and has a range of differentials that need to be excluded. Radiology plays an important role in this differentiation. Differential diagnosis appendicular mass appendicular abscess appendicular mucocele appendicular neoplasms ileoceca...
Article

Subdiaphragmatic free gas

Subdiaphragmatic free gas is one of the ways of detecting presence of free intraperitoneal gas (i.e. pneumoperitoneum). It is the presence of free, extraluminal gas in the anterior subhepatic space.  Radiographic features Plain radiograph Subdiaphragmatic free gas is well appreciated as the g...
Article

Gasless abdomen

A gasless abdomen refers to a paucity of gas on abdominal radiography, and the specific cause can usually be identified when the patient's history is known. Common causes include: high obstruction: gastric outlet obstruction, congenital atresia small bowel obstruction bowel ischemia ascites ...
Article

Widening of the presacral space (differential)

Widening of the presacral space is one of the diagnostic indicators of diseases involving pelvic pathology and rectal involvement. It is ideally measured on barium studies at the level of S3/4 disc level on lateral radiographs and the normal value of the presacral space is <15 mm in adults.​ Th...
Article

Complications following gastric banding

There are many complications that can occur following gastric banding. It is helpful to divide these into early and late post-surgical complications. Clinical presentation Although the exact mode of presentation can vary depending on the underlying complication common modes of presentation tha...
Article

HIV/AIDS: gastrointestinal manifestations

Gastrointestinal manifestations of AIDS are protean and can be broadly divided into opportunistic infections and tumors: Infections viral  cytomegalovirus (CMV) herpes simplex virus (HSV) primary infection with HIV fungal candidiasis histoplasmosis bacterial tuberculosis mycobacterium...
Article

Apple core sign (colon)

The apple core sign, also known as the napkin ring sign (bowel), is most frequently associated with constriction of the lumen of the colon by a stenosing annular colorectal carcinoma. Differential diagnosis The appearance of the apple-core lesion of the colon also can be caused by other diseas...
Article

Gastric outlet obstruction

Gastric outlet obstruction is a syndrome resulting from mechanical obstruction of stomach emptying. Pathology Etiology Gastric outlet obstruction can be due to malignant or benign causes. Malignant adenocarcinoma (second most common 4) GIST lymphoma (less common than other mali...
Article

Hemoperitoneum

Hemoperitoneum (plural: haemoperitoneums) is the presence of blood within the peritoneal cavity. Pathology Etiology penetrating or non-penetrating abdominal trauma (often with associated organ injury) 1 ruptured ectopic pregnancy ovarian cyst rupture aneurysm or pseudoaneurysm rupture neo...
Article

Splenic calcification

Splenic calcifications can occur in various shapes and forms and can occur from a myriad of etiological factors. The usual calcification observed in radiographs are the multiple, miliary form presenting numerous small rounded densities averaging from three to five millimeters in diameter where ...
Article

Terminal ileitis (differential)

The differential diagnosis for a terminal ileitis is quite extensive, and includes: inflammatory bowel disease Crohn disease (most common) backwash ileitis due to ulcerative colitis infectious colitis Yersinia spp.  Yersinia enterocolitica Yersinia pseudotuberculosis Salmonella spp. ​Sa...
Article

Pancreatic calcifications

Pancreatic calcifications can arise from many etiologies. Punctate intraductal calcifications chronic pancreatitis alcoholic pancreatitis (20-40%) 2  intraductal, numerous, small, irregular preponderant cause of diffuse pancreatic intraductal calcification gallstone pancreatitis (2%) 2 ​m...
Article

Periampullary tumors

Periampullary tumors are those that arise within 2 cm of the ampulla of Vater in the duodenum. Tumors that fall under this group include four main types of tumors 1,4 that will be approached in their specific articles: pancreatic head/uncinate process tumors: includes pancreatic ductal adenoca...
Article

Pancreatitis

Pancreatitis (plural: pancreatitides) refers to inflammation involving the pancreas.  It has various forms which can be classified in many, many ways according to time of onset, etiological agent or associated pathology. acute pancreatitis interstitial edematous pancreatitis necrotizing panc...
Article

Intra-abdominal calcification (neonatal)

Intra-abdominal calcification in a neonate can be caused by a number of pathologies that cause calcification within the peritoneal space or within organs. Pathology Etiology Meconium peritonitis The commonest cause is meconium peritonitis which is the result of aseptic peritonitis secondary ...
Article

Medical devices in the abdomen and pelvis

Medical devices in the abdomen and pelvis are important to be recognized, just like medical devices of the chest. We often ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications. Gastrointestinal devices tube...
Article

Cystic retroperitoneal lesions

Cystic retroperitoneal lesions carry a relatively broad differential, which includes: retroperitoneal lymphatic malformation retroperitoneal mucinous cystadenoma retroperitoneal cystic teratoma retroperitoenal cystic mesothelioma pseudomyxoma retroperitonei with cystic change perianal muci...
Article

Bulging duodenal papilla

Bulging duodenal papilla​ is a conical or cylindrical protuberance at the medial aspect of the descending or horizontal duodenum at the site of the sphincter of Oddi. It is a finding on small bowel follow-though (and endoscopy) and has a relatively long differential. On cross-sectional imaging, ...
Article

Tumors of the small intestine

The small intestine is rarely the site of malignant tumors, although it accounts for ~75% of the entire length of the GI tract and more than 90% of the mucosal surface. Approximately 40 different histologic tumor types have been described.  In this article, an overview will be given of the most...
Article

Diaphragmatic rupture

Diaphragmatic rupture often results from blunt abdominal trauma. The mechanism of injury is typically a motor-vehicle collision. Epidemiology Given that the most common mechanism is motor vehicle collisions, it is perhaps unsurprising that young men are most frequently affected. The estimated ...
Article

HIV associated neoplasms

HIV-associated neoplasms are numerous and can be broadly divided into two groups: AIDS-defining malignancies associated but not AIDS defining malignancies AIDS-defining malignancies The development of these malignancies in HIV affected individuals generally implies progression to AIDS 4: Ka...
Article

Splenic lesions and anomalies

There are a number of splenic lesions and anomalies: Gamuts hypervascular splenic lesions Congenital anomalies accessory spleen wandering spleen asplenia polysplenia splenogonadal fusion retrorenal spleen Mass lesions Benign mass lesions splenic cyst splenic pseudocyst splenic hem...
Article

Double bubble sign (duodenum)

The double bubble sign is seen in infants and represents dilatation of the proximal duodenum and stomach. It is seen in both radiographs and ultrasound, and can be identified antenatally 2. Pathology Causes include 1,2: congenital obstruction duodenal web duodenal atresia duodenal stenosis...
Article

Dysphagia

Dysphagia refers to subjective awareness of difficulty or obstruction during swallowing. It is a relatively common and increasingly prevalent clinical problem. Odynophagia is the term for painful swallowing. Fluoroscopy is the mainstay of imaging assessment but manometry can help evaluate the e...
Article

Lower abdominal/pelvic calcification

Causes of calcifications in the lower abdomen and pelvis include: vascular calcifications atherosclerosis aneurysm phlebolith urogenital uterine fibroid ovarian dermoid prostatic calcification seminal vesicle and ductus deferens calcification bladder stones gallstones dropped stones ...
Article

Diffuse small bowel disease

Diffuse small bowel disease may be caused by a number of conditions may be generalized multisystem disorders or conditions that effect the bowel in a global fashion: sprue scleroderma Whipple's disease amyloidosis hypoproteinemia giardiasis intramural hemorrhage radiation enteritis smal...
Article

Intra-abdominal calcification

Intra-abdominal calcification is common and the causes may be classified into four broad groups based on morphology: Concretions These are discrete precipitates in a vessel or organ. They are sharp in outline but the density and shape vary but in some cases, they may be virtually pathognomonic...
Article

Splenomegaly

Splenomegaly refers to enlargement of the spleen. The upper limit of the normal adult splenic length is traditionally cited at 12 cm, but lengths upwards of 14 cm can be seen in normal, taller males 7. Terminology Massive splenomegaly is variably defined, including when the spleen is 5 standar...
Article

Lower gastrointestinal bleeding (differential)

Lower gastrointestinal bleeding usually occurs distal to the ligament of Treitz, and has a wide differential diagnosis: diverticular disease enterocolitis infective Crohn’s disease ulcerative colitis ischemic colitis vascular malformation vascular ectasia angiodysplasia arteriovenous m...
Article

Upper gastrointestinal bleeding (differential)

An upper gastrointestinal bleed usually refers to bleeding proximal to the ligament of Treitz. Pathology Aetiolology peptic ulcer gastritis esophagitis duodenitis Mallory-Weiss tear varices tumor vascular abnormality vascular ectasia angiodysplasia Dieulafoy lesion vascular malform...
Article

Splenic cyst

Splenic epithelial cysts, also known as splenic epidermoid cysts or primary splenic cysts, are unilocular fluid lesions with thin and smooth walls and no enhancement. They represent ~20% of cysts found in the spleen, and are usually an innocuous incidental imaging finding. Note that most (~80%)...
Article

Small bowel fold thickening (differential)

The differential diagnosis of small bowel fold thickening is broad. Diffuse fold thickening may be "regular and smooth" or "irregular and nodular". Regular, smooth generalized thickening edema congestive cardiac failure (CCF) hypoalbuminemia lymphatic obstruction angioneurotic edema infec...
Article

Peritoneal calcification

Peritoneal calcification is seen in a limited number of conditions that result in calcification of peritoneal structures. Therefore, the differential diagnosis is small: psammoma bodies in malignancy (most frequently cystadenocarcinoma of the ovary): fine sand-like calcification pseudomyxoma p...
Article

Pancreatic neoplasms

There are numerous primary pancreatic neoplasms, in part due to the mixed endocrine and exocrine components. Classification Classification based on function exocrine: ~99% of all primary pancreatic neoplasms pancreatic ductal adenocarcinoma (commonly known as pancreatic cancer) 90-95%  cyst...
Article

Omental cake

Omental cake refers to infiltration of the omental fat by material of soft-tissue density. The appearances refer to the contiguous omental mass simulating the top of a cake. Masses on the peritoneal surfaces and malignant ascites may also be present.  Pathology The most common cause is metasta...
Article

Nodular filling defects of duodenum (differential)

Nodular filling defects due to mucosal lesions in the duodenum are due to a number of processes. For a differential list which includes non-mucosal lesions see duodenal filling defects. The differential diagnosis for mucosal lesions includes:  heterotopic gastric mucosa 1-2 mm clustered onl...
Article

Discrete colonic ulceration

Discrete colonic ulcerations are nonspecific findings, and can be due to: Crohn disease infective colitis Yersinia entercolitis shigellosis tuberculosis cytomegalovirus (CMV) amoebic colitis vasculitic colitis Behcet disease
Article

Cystic (necrotic) lymph nodes

Cystic or necrotic appearing lymph nodes can be caused by a number of infectious, inflammatory or malignant conditions: Systemic squamous cell carcinoma metastases treated lymphoma leukemia plasmacytoid T-cell leukemia acute myeloid leukemia viral lymphadenitis herpes simplex lymphadenit...
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

Colonic stricture

Colonic strictures can be long (>10 cm) or short. Short scirrhous colorectal carcinoma (apple core sign) post surgical (anastamotic stricture) Long malignancy scirrhous colorectal carcinoma gastrointestinal lymphoma inflammatory bowel disease ulcerative colitis Crohn disease post radi...

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.