R1 Oral Body

Front 1

Linitis Plastica

Back 1

Stomach with leather bottle appearance
Usually adenocarcinoma with submusocal infiltration

Radiographic features
Barium meal
Due to the increased rigidity of the wall, the stomach cannot be adequately distended
Narrow lumen seen
normal mucosal fold pattern is absent, either distorted, thickened or nodular

CT
Typically the stomach is diffusely thickened with a small lumen. Evidence of nodal involvement or wide spread metastatic disease should also be sought.

Ddx
• neoplastic (gastric adenoCA, metastases from tit,lung,lymphoma)
• diffuse gastric diverticula (rare)
• inflammatory
o radiotherapy
o eosinophilic enteritis
o granulomatous disease
 Crohn's disease
 tuberculosis
• scarring (e.g. ingestion of corrosives)
• gastric amyloidosis

Front 2

Achalasia

Back 2

Achalasia
failure of organized peristalsis with impaired relaxation at the level of LES giving marked dilatation of the oesophagus and food stasis.
Present with dysphagia, chest pain / discomfort and eventual regurgitation. Initially symptoms are intermittent.
CXR
Chest x-ray findings include :
right convex opacity behind right cardiac border; occasionally left convex opacity if thoracic aorta tortuous
air-fluid level due to stasis in thoracic oesophagus filled with retained secretions and food
small / absent gastric air bubble
anterior displacement and bowing of trachea on the lateral view
The chronic presence of fluid debris in the oesophagus makes patients very prone to aspiration and thus patchy bilateral alveolar opacities representing acute or chronic aspiration pneumonia may be seen.
Barium
failure of normal peristalsis to clear the oesophagus of barium when the patient is in the recumbent position, with no primary waves identified
uncoordinated, non-propulsive, tertiary contractions
oesophageal body dilatation, which is typically maximal in the distal esophagus
pooling or stasis of barium in the oesophagus when the oesophagus has become atonic or non contractile (late feature in the disease)
when barium column is high enough (patient standing) the hydrostatic pressure can overcome the LOS pressure allowing passage of oesophageal content
incomplete LOS relaxation that is not coordinated with oesophageal contraction
bird beak sign
Differential diagnoses
achalasia : distal segment of narrowing is less than 3.5 cm
central and peripheral neuropathy
scleroderma
oesophageal malignancy
oesophageal stricture

Front 3

Gastric Lymphoma

Back 3

•


TERMINOLOGY

Definitions
• Gastric metastases from primary cancer
• Lymphoma: Malignant gastric tumor of B lymphocytes


IMAGING

Fluoroscopic Findings
o Malignant melanoma metastases
 Solitary/multiple discrete submucosal masses
 "Bull's-eye" or "target" lesions: Centrally ulcerated submucosal masses
 "Spoke-wheel" pattern: Radiating superficial fissures from central ulcer
 Giant cavitated lesion: Large collection of barium (5-15 cm) communicating with lumen
 Small or large lobulated masses
 Mucosal nodularity, spiculation, ulceration
o Esophageal squamous cell metastasis
 Large submucosal masses, central ulceration
o Esophageal adenocarcinoma (from Barrett mucosa)
 Large polypoid/ulcerated mass in gastric fundus
 Subtle findings of cardia: Small ulcers & nodules
CT Findings
• Demonstration of lesions facilitated by negative contrast agents (water, gas)
• Hematogenous spread of metastases to stomach
o Linitis Plastica differential
 Markedly thickened gastric wall with enhancement, folds preserved, seen in proximal stomach; antrum spared
 Mimics primary scirrhous carcinoma of stomach
• Lymphatic spread of metastases to stomach
o Esophageal Ca: Growth in gastric cardia or fundus
o Multiple, well-defined, ↓ HU enlarged nodes
 Characteristic of squamous cell metastases
• Direct invasion of stomach
o Distal esophageal adenocarcinoma: Barrett mucosa
 Polypoid, lobulated mass in gastric fundus
 Indistinguishable from primary gastric carcinoma
Ultrasonographic Findings
• Grayscale ultrasound
o Endoscopic ultrasonography (EUS)
 Hypoechoic mass disrupting normal wall layers
 Selective/diffusely thickened echogenic wall layers

Front 4

Esophageal Diverticula

Back 4

Front 5

Esophageal Filling Defects

Back 5

Front 6

Esophageal Narrowings

Back 6

Front 7

Esophageal Strictures

Back 7

Front 8

Biliary Duct Dilatation

Back 8

Front 9

Bosniak Criteria

Back 9

Front 10

Renal Cyst Imaging Features

Back 10

Front 11

DDX pneumatosis

Back 11

• Pneumatosis is a radiographic finding, not a disease process
o Must correlate with patient history, clinical signs & symptoms to determine its significance
 Check WBC, lactate, amylase


DDx

Ischemic Enteritis & Colitis & SBO
• Spherical or linear collections of gas in submucosa of affected bowel
• Often associated with portal venous gas; SB ischemia usually due to occlusion of SMA or SMV
o Colonic ischemia more often due to hypoperfusion; not thrombotic
Iatrogenic (Post-Operative or Endoscopy)
• Bowel-to-bowel anastomosis. G/J tubes – air to leak from lumen into wall; asymptomatic
Drugs (Steroids, Chemo)

Pseudopneumatosis (Mimic)
• Gas may be trapped against the inner wall of bowel, simulating pneumatosis
• Very common in cecum, ascending colon
• Lung (Asthma, COPD, pulmonary fibrosis, cystic fibrosis, ventilator)
Collagen Vascular Disease
• Any "collagen vascular disease" may cause pneumatosis
• Intramural gas may result from the bowel disease itself, associated medications (e.g., corticosteroids), or ischemia
o Must correlate with clinical & laboratory evidence of disease exacerbation or ischemia
Necrotizing Enterocolitis
• Common cause of pneumatosis in neonates




Pneumatosis Cystoides Intestinalis (like bullae in colon wall)

Intestinal Trauma
• Serosa of bowel may be avulsed ("degloving injury")
• Leads to devascularization & ischemia of bowel
Small Bowel Transplantation

Inflammatory Bowel Disease
• Crohn disease, ulcerative colitis, others
• Any disease that causes ulceration of bowel mucosa can cause pneumatosis
• Patients are often on steroid medications that may also cause pneumatosis
Graft vs. Host Disease
• Bone marrow transplant recipients
• Clinical triad: Damage to gut, skin, liver
• Pneumatosis does not necessarily indicate ischemia
o Patients are receiving medications (steroids, immunosuppression) associated with "benign pneumatosis"

Front 12

Cystic Pancreatic Mass

Back 12

Pancreatic Pseudocyst
Pancreatic abscess
Neoplastic (Mucinous cystic pancreatic neoplasm, IPMT, pancreatic ductal CA)
AD poly cystic kidney
VHL

Mimics ie Ascites, Duo Tic

Front 13

Adrenal Mass

Back 13

Adenoma (lipid rich,fast washout)
Mets (next most common)
1' Adrenal Cortical CA
Adrenal Myelipoma
Pheo
Hemorrhage
Cyst

Front 14

Carcinoid

Back 14

Imaging
Most common primary small bowel tumor beyond ligament of Treitz
Appendix > ileum > duodenum > other sites

Front 15

Carcinoid DDx

Back 15

DDX
Sclerosing mesenteritis
Infiltrated jejunal mesentery
Intestinal metastases and lymphoma
Desmoid
Mesenteric and small bowel trauma
Small bowel carcinoma

Front 16

Carcinoid Findings

Back 16

IMAGING

General Features
• Best diagnostic clue: Solitary, well-/ill-defined, enhancing distal ileal mass with mesenteric metastases
• Location: Appendix > ileum > duodenum > other sites
• Size: Varies from < 1 cm to a few cm
• Other general features
CT Findings
• Submucosal tumors
o Solitary or multiple, well-defined enhancing lesion
o Better visualization of enhancing mural mass with enteric water as contrast agent
o More difficult to detect primary than metastatic foci
o Ill-defined, heterogeneous mesenteric mass
o Calcification within mesenteric mass (up to 70%)
o Occasionally tumor may be of cystic density
o Tumor may show spiculation with stellate pattern
o ± tethering, fixation, retraction of small bowel loops
 Due to mesenteric fibrosis and desmoplastic reaction
 Desmoplastic reaction: Finger-like projections of mass into adjacent mesentery
o ± encasement and narrowing of mesenteric vessels
• Hypervascular Liver metastases

Front 17

Ddx Pneumoperitoneum

Back 17

Duodenal Ulcer (intra and extraperitoneal is possible)
Gastric Ulcer
Diverticulitis (few locules near sigmoid is usual)
Intestinal Trauma
Iatrogenic
Bowel Anastomotic Leak
Thoracic pathology may mimic or cause pneumoperitoneum (PTX, Atelectasis, Cystic lung disease)

Front 18

SBO causes

Back 18

CT Findings
Dilated SB loops > 2.5 cm ± air-fluid levels

Causes:
1. Extrinsic lesions: Adhesions, Hernia, Peritoneal carcinomatosis, Appendicitis
2. Intrinsic lesions: Adenocarcinoma, Crohn disease, tuberculosis, radiation enteropathy
3. Intraluminal lesions: Gallstones, foreign bodies, bezoars, Ascaris worms

Front 19

Delayed Nephrogram

Back 19

Obstruction of UPJ (calculi, tumour, TCC, RCC, Mets, 1’ bowel or pelvic malignancy, trauma)
Vascular Cause (Renal artery stenosis, vein thrombosis/stenosis)
ATN, CIN
Shock
Pyelonephritis

Front 20

Striated Nephrogram

Back 20

Renal Trauma
Infarct
MSK
Acute ureteral obstruction
Vasculitis
M/M
Rhabdomyolysis
RCC, Mets, Lymphoma

Front 21

Cystic Peritoneal Mass

Back 21

Front 22

Solid Peritoneal Mass

Back 22

Front 23

Liver lesions w/ a scar

Back 23

Front 24

Hemangioma on CT

Back 24

Front 25

HCC Features on CT

Back 25

Front 26

FNH Features on CT

Back 26

Front 27

Cystic Hepatic Mass

Back 27

Front 28

CholangioCA Features

Back 28

Front 29

Characterization of Liver Masses

Back 29

Front 30

approach to hypervascular mass

Back 30