Gastrointestinal tract

Hydrops fetalis

Small bowel versus large bowel on an abdominal radiograph

Epiploic appendagitis

Meckel diverticulum

Retrorectal mass

Developmental cysts Epidermoid Dermoid Enteric (cystic hamartoma or rectal duplication) Sacral lesions Teratoma Anterior sacral meningocele Chordoma  Lymphangioma Anorectal lesions Lipoma  GIST Anal gland cyst

8th edition TNM anal cancer staging

Stage I  T1 – tumor not more than 2 cm in greatest dimension N0 – no regional lymph nodes M0 – no distant metastases Stage IIa  T2 – tumor more than 2 cm but not more than 5 cm in greatest dimension N0 – no regional lymph nodes M0 – no distant metastases Stage IIb…

Differentials based on degree of bowel wall enhancement

Avid Ischemia  Inflammatory bowel disease Malignancy Acute infection Moderately homogenous  Malignancy Lymphoma Chronic inflammatory bowel disease Chronic ischemia Heterogeneous Malignancy Lymphoma (usually after treatment) Infiltration (endometriosis) Layered enhancement (target sign) Inflammatory bowel disease Infection Vasculitis Ischemia Graft versus host disease Radiation colitis Reduced Ischemia 

Misty mesentery

Mesenteric edema Hypoalbuminemia Portal hypertension Cirrhosis  Nephrotic syndrome Heart failure Portal vein and SMV thrombosis Trauma Neoplasm Surgery Lymphedema  Inflammation Neoplasm Surgery Radiation therapy Congenital abnormality Inflammation Pancreatitis Appendicitis Diverticulitis Inflammatory bowel disease Tuberculosis Amyloidosis Mesenteric panniculitis Hemorrhage Trauma Bowel ischemia Coagulopathy Neoplasms Non-hodgkin lymphoma Mesothelioma Carcinoid Colon, pancreatic, ovarian, breast cancer Melanoma Gastrointestinal stromal…

Strictures of small intestine

Crohn disease Tumors  Primary carcinoma Carcinoid  Lymphoma  Invasion from other organs Metastases Tuberculosis Actinomycosis Strongyloidiasis Anisakiasis  Radiation injury Ischemia Intramural hemorrhage Diverticular mass Appendiceal mass Endometriosis Eosinophilic gastroenteritis Idiopathic ulcerative enteritis Behcet disease NSAIDs

8th edition TNM esophageal cancer staging

T T1a Invasion of lamina propria or muscular mucosa T1b Invasion of submucosa T2 Invasion of muscularis propria T3 Invasion of adventitia T4a Resectable tumor invading pleura, pericardium or diaphragm T4b Unresectable tumor invading aorta, airway, vertebrae etc N N0 No lymph nodes  N1 One to two regional lymph nodes  N2 Three to six regional…

Differentials for right iliac fossa pain

Appendicitis Ectopic pregnancy Ovarian cyst with or without torsion Salpingitis Endometriosis Diverticulitis Infectious ileocecitis Crohn’s disease Malignancy Intussusception Meckel’s diverticulum Cholecystitis Urolithiasis Mesenteric adenitis

Small bowel versus Large bowel in the plain radiograph

Small bowel Central position Calibre > 3.5 cm and < 5 cm Presence of valvulae conniventes Large bowel Peripheral position Calibre > 5 cm Presence of haustra

Pneumoperitoneum without peritonitis

Silent perforation that seals itself The elderly Patients on steroids Unconscious patients First 7 post operative days Peritoneal dialysis Perforated cyst in pneumatosis intestinal Pneumomediastinum tracking down Stercoral ulceration Vaginal tubal entry of air

Omental infarction

Due to vascular compromise of greater omentum  Primary omental torsion is usually right sided, due to congenital or vascular variations  Seen in obesity Secondary infarction – surgery, abdominal inflammation, tumors, hernial sacs Treatment is conservative Imaging  CT: heterogeneous large omental mass with hyper attenuating streaks in right lower quadrant. Larger than 5 cm.  Read more…

Sclerosing peritonitis

Encapsulating peritoneal sclerosis Rare, chronic inflammation of peritoneum Seen in patients undergoing continuous ambulatory peritoneal dialysis Rare causes: abdominal TB, recurrent peritonitis, ventriculo-peritoneal shunts, long term beta blocker treatment, sarcoidosis Asymptomatic or have nausea, anorexia, malnutrition, weight-loss, recurrent small bowel obstruction Imaging  CT: ideal. Smooth or irregular nodular peritoneal thickening with calcification. Marked enhancement of…

Meckel diverticulum

Failure of yolk sac to close in fetal life 0.5-3% of population Seen on anti mesenteric border of ileum 30-90 cm from ileocecal valve Size from 0.5 to 13 cm 20-40% cases symptomatic Complications: ulceration, bleeding, perforation, inflammation, intussusception, internal hernia, volvulus, adhesions Ectopic gastric mucosa in 20% of adults and all children who present…

Radiation enteritis

Type of intestinal ischemia Damage to vascular endothelial cells Results in endarteritis obliterans Distal ileum and pelvic loops commonly involved Time interval between radiation and symptoms variable Colicky abdominal pain, diarrhea, malabsorption, intermittent small intestinal obstruction Imaging  Thickening of valvulae conniventes, mural thickening, effacement of mucosal pattern, ulceration, fixation and angulation of small intestinal loops…

Acute mesenteric ischemia

Arterial embolism or thrombosis, venous occlusion or low-flow states Severe abdominal pain at presentation MDCT crucial for diagnosis. Oral water with i.v. contrast and dual phase imaging. Sensitivity 93%. Specificity 96% Imaging  Acute transmural infarction: mural thinning, small intestine dilatation, reduced or absent mural enhancement  Non-occlusive mesenteric ischemia: mural thickening, mucosal hyper enhancement.  Mesenteric venous…


Common in older patients Muscle abnormality in sigmoid colon with out pouching from colonic wall Deposition of elastin in taeniae cause contraction and shortening of bowel with corrugation of mucosa and circular muscle layers – this causes thickening of sigmoid with interdigitating folds Diverticula arise at points of weakness where the vasa recta penetrate the…

Coeliac disease

Gluten-related immune-mediated enteropathy In genetic susceptible individuals 1 in 200 people Malabsorption, diarrhea, weight loss, steatorrhea, malnutrition, anemia, abdominal pain Greater risk of malignancy of small intestine – lymphoma (enteropathy associated T-cell lymphoma) and adenocarcinoma Abnormal villous pattern in jejunal biopsy Imaging Barium study Dilatation of bowel loops Increased intestinal fluid Straightened and thickened valvulae…

Ischemic colitis

Common in elderly 90% cases in patients >60 years old Sudden onset abdominal pain, rectal bleeding Etiology Mesenteric occlusion: arterial or venous Mechanical: strangulation or raised intracolonic pressure proximal to an obstruction Low-flow states Young patients: hypercoagulable states, vasculitis, long-distance running, cocaine use Spectrum Splenic flexure most commons site (watershed zone between SMA-IMA) Right colon…

Epiploic appendagitis

Infection of an epiploic appendage Most common in sigmoid or caecum Acute pain and tenderness similar to diverticulitis or appendicitis Resolves in 2 weeks time USG: non-compressible pericolic hyperechoic ovoid mass immediately under anterior abdominal wall CT: focal hyperattenuation with central area of fat density Read more Singh, Ajay K., et al. “Acute epiploic appendagitis…

8th edition TNM colorectal cancer staging

Stage Tumor extent Dukes 5-year survival I T1 – invades submucosa T2 – invades muscularis propria No nodal involvement, no distant metastasis A 85-95% II T3 – invades outside muscularis propria T4a – invades visceral peritoneum T4b – invades other organs No nodal involvement, no distant metastasis B 60-80% III N1 – 1 to 3…

8th edition AJCC gastric cancer staging

T staging TX Primary tumor cannot be assessed T0 No evidence of primary tumor Tis Carcinoma in situ: intraepithelial tumor without invasion of the lamina propria, high-grade dysplasia T1 Tumor invades lamina propria, muscularis mucosa or submucosa T1a Tumor invades lamina propria or muscularis mucosa T1b Tumor invades the submucosa T2 Tumor invades the muscularis…

Pseudomembranous colitis

Follows administration of antibiotics Clindamycin, lincomycin Clostridium difficile commonly seen Abdominal radiograph Abnormal in 1/3 cases Colonic dilatation (32%) Thumbprinting Thickened haustra Abnormal mucosa (18%) Transverse colon is most commonly affected, whole colon often involved CT Normal in 39% cases Markedly thickened mucosa Edema in submucosa Nodular mucosal thickening Accordion sign Mild pericolonic fat inflammatory…

Pneumoperitoneum without peritonitis

Silent perforation of viscus that seals itself: elderly, patients on steroids, unconscious patients, presence of other serious medical conditions Post-operative (up to 7 days) Peritoneal dialysis Perforated cyst in pneumatosis intestinalis Tracking down from pneumomediastinum Stercoral ulceration Vaginal-tubal entry of air

Diffuse esophageal spasm

dysmotility disorder five times less common than achalasia strong repetitive non-propulsive contractions interspersed with normal peristaltic waves these contractions may obliterate esophageal lumen sometimes presents with chest pain barium swallow corkscrew or curling esophagus due to strong non-propulsive contractions marked esophageal wall thickening due to high pressure, occasionally diverticula may be seen

Barrett’s oesophagus

due to chronic gastro-oesophageal reflux causes a specialized non-secretory columnar epithelium to grow cranially in previous site of squamous epithelium 2 cm or more of columnar epithelium needed to reach this diagnosis may develop high grade dysplasia 40 fold risk of developing esophageal carcinoma. 15% develop adenocarcinoma >2 cm involvement needs 2 yearly endoscopic surveillance…


midline anterior abdominal wall defect solid viscera or bowel may herniate extruded contents covered in a sac large lesions: due to complete failure of fusion of lateral body folds bowel only lesions: due to persistence of physiological herniation of gut after 10th week of fetal development umbilical cord inserts at tip of defect giant omphalocele:…


small split in ventral abdominal wall usually to right of umbilicus no associated anomalies due to intrauterine vascular accident or asymmetry in lateral body wall folds with failure of fusion seen in mothers < 20 years serious complications: short bowel syndrome, liver disease due to intestinal failure or dysmotility, necrotizing enterocolitis imaging bowels floating in…

A ring

inferior esophageal sphincter 2-4 cm proximal to B ring thicker ring produced by active muscle contraction

Schatski or B ring

ring of mucosal tissue at lower border of phrenic ampulla marks junction between squamous and columnar epithelium (Z line) usually 2-3 mm thick associated with small sliding hiatus hernia sometimes incomplete, part of it seen as incisural notch (on greater curve of stomach)

Meconium aspiration syndrome

meconium stained amniotic fluid when infant is born symptoms that otherwise cant be explained meconium below the level of vocal cords seen in post mature babies fetal hypoxia causes intestinal hyperperistalsis, passage of meconium, which is aspirated by fetus imaging aspiration of meconium – complete or partial obstruction of distal airways, lead to ball-valve effect…

Barium meal appearance of parts of stomach

Positions of appendix

Pyloric stenosis signs


Bayonet sign in dysphagia lusoria

Umbilical hernia

When your wall is not so strong anymore.. things start popping out! #Foamed #FoamRad #Voxelz #Radiopaedia #CT #Hernia

Sigmoid colocolic intussusception

Clinical presentation Middle aged gentleman with acute onset colicky lower abdominal pain, nausea vomiting and constipation. Empty rectum on per rectal examination CT abdomen and pelvis Findings and Discussion Read more Wilson, Abralena, George Elias, and Rulx Dupiton. “Adult colocolic intussusception and literature review.” Case reports in gastroenterology 7.3 (2013): 381-387. Marinis,…

Umbilical hernia

Clinical presentation 45 year old lady on Warfarin for recent left lower limb deep venous thrombosis. Previous ultrasound revealed a right ovarian cyst. So the patient came for a CT to assess both ovarian cyst and venous thrombosis status. Previous ultrasound and venous doppler revealed complete thrombosis of entire left lower limb extending proximally up…

Motility and other miscellaneous disorders of esophagus

Malignant tumors of Esophagus

The common and the rare tumors of the esophagus

Benign tumors of Esophagus

Run down of the common and rare benign neoplasms of the esophagus

GERD and peptic esophagitis

Pathological changes in the esophagus secondary to acid reflux and the radiological imaging cues.

Hiatus Hernia

Hiatus hernia review article – key diagnostic imaging features

Imaging the Esophagus

A run down of the modalities available to us for imaging the esophagus.

Anatomy of the Esophagus

Review of the anatomy of the esophagus