GI Flashcards
1
Q
Oesophageal impressions
A
C5- criccopharyngeus
Aorta
Left main bronchus
Left atrium
**Aberrant right subclavian - dysphagia lusoria
2
Q
Rings + webs
A
OESOPHAGEAL WEB- anterior indentation in ANTERIOR CERVICAL oesophagus
*Plummer Vinson
Schatzki ring- circumferentialdistal oesophagus <13mm, assoc: hiatus hernia
DDX: cancer, stricture
3
Q
Oesophagitis findings
A
PEPTIC- lower sphincter dysfunction,
▸ thickened longitudinal folds (>3 mm) ▸ multiple fine ulcers = punctate or granular appearance ▸ larger discrete punched-out ulcers can develop ▸ ulceration seen above GOJ
>Zollinger Ellison, Scleroderma
BARRETTS- normal squamous > adenoma, RETICULR web-like
mucosal pattern + mid-esophagus stricture
INFECTION
* Candida: PLAQUE LIKE, linear / irregular filling defects, longitudinally oriented, separated by normal mucosa, SHAGGY
*HIV/ transplant/ sclerderma/ achalasia * UPPER ESOPHAGUS
- HSV: vesicles in upper / mid= small sessile filling defects ▸ punched-out superficial ulcers ▸ advanced disease = diffuse ulceration HAS HALO
- CMV/HIV: giant oesophageal ulcers
- Drugs: KCL= deep ulceration leading > stricture formation
Post NG tube + RADIATION = LONG, SMOOTHSTRICTURE
EOSINOPHILIC OESOPHAGITIS= concentric mucosal ring-like strictures
Feline esophagus=normal variant, multiple THIN transverse folds
4
Q
Oesophageal lesions
A
- Mesenchymal = SUBMUCOSA> leiomyomyoma, lipoma, haemangioma
- Adenoma= mucosal= malignant potential
- Fibrovascular polyp = fatty, cervical esophagus
- Inflammatory polyp= enlarged gastric mucosal fold that protrudes up into the lower esophagus
5
Q
Oesophageal mets
A
Gatric/ lung/ breast
6
Q
Oesophageal motility disorders
A
- Achalasia: distal oesophagus doesnt relax, massively dilated esophagus + bird’s beak stricture near GOJ, increased risk squamous ca
*CHAGAS= secondary cause
-Scleroderma: lack of peristalsis distal 2/3 esophagus > marked esophageal dilation> aspiration + candida
- Diffuse spasm: repetitive, non-propulsive contractions, corkscrew esophagus
- Tertiary contractions= non propulsive, seen in achalasia
7
Q
Types of diverticula
A
- Pulsion: increased pressure, near GOH, round + won’t empty
-Traction:pulled by mediatinal, traingular and will empty, inflammation eg. nodes - Zenker: failure of criccopharyngeus to relax, hypopharynx ABOVE cricopharyngeus, POSTERIOR. >cricopharyngeus usually hypertrophied LATERAL VIEW
- Killian Jamieson: proximal cervical esophagus, area of weakness BELOW cricopharyngeus, ANTEROLATERAL, * AP view * bilateral
- Pseudodiverticulosis: multiple tiny flask shaped outpouchings> dilated submucosal glands from chronic reflux esophagitis./ diabetics/ chronic alcohol
Associated - smooth stricture in mid/upper esophagus, CANDIDA
8
Q
Types of volvus
A
GASTRIC
Organoaxial- long axis, adults, hernia
Mesentero- short axis, kids, intrathoracic stomach with two air fluid levels
Assoc: traumatic diaphragmatic rupture kids
CAECAL
SIGMOID
9
Q
Gastric folds
A
- Inflammatory: smooth thickening,
- Nodular > lymphoma/ carcinoma
- Eosinophilic: thickened folds in stomach + small bowel, concentric rings ANTRUM
OTHER CAUSES:
> Menetriers: loss of protein/ cl
>Zollinger Elllison: gastrinoma> duodenum or pancreas, elevated gastrin, MEN 1 “spares antrum”
> Crohns
> lymphoma
Sarcoid
> gastric varices: linear often serpentine, filling defects causing a scalloped contour.
10
Q
Gastric ulcers benign vs malignant
A
MALIGNANT
Width > Depth
Located within Lumen
Nodular, Irregular Edges
Folds adjacent to ulcer
Aunt Minnie: Carmen Meniscus Sign Can be anywhere
BENIGN
Depth > Width
Project beyond the expected lumen Sharp Contour
=Folds radiate to ulcer
Aunt Minnie: Hampton’s Line Mostly on Lesser Curvature
11
Q
Gastric polyps
A
- Hyperplastic/inflammatory polyp: usually always benign
- Fundic gland polyps: small, round, well-circumscribed radiolucent filling defects, polyposis syndromes
- Adenomatous polyp: can progress to adeno, atrophic gastritis, normally solitary
- Hamartomatous polyps: Peutz- Jeghers, juvenile polyposis, Cronkhite-Canada syndromes
12
Q
Gastric lymphoma
A
Lymphoma- lymphadenopathy at/ below renal hila CF gastric carcinoma
* Stomach =common extranodal site for NHL
Diffuse wall thickening WITHOUT gastric outlet obstruction, “crosses the pylorus”
H Pylori = risk factor
13
Q
Gastric adenocarcinoma
A
Lymphatic spread =along lesser curvature> gastrohepatic ligament > greater curvature.
> large, ulcerated, heterogenous mass= asymmetric wall thickening - focal and nodular >12mm.
Krukenberg mets
Obstructs if involves antrum
- RF: pernicious anaemia, adenomatous polyps, partial gatrectomy
14
Q
Roux en Y complications
A
- SBO> internal hernias, more common with lap procedure
- Afferent loop syndrome (intermittent mechanical obstruction of afferent limb-duodenum part)
- Leak: Gastric pouch or blind-ending jejunal limb
- Stomal stenosis: Narrowing of GJ stoma = dilation of the gastric pouch and distal esophagus
- Gatrograffic fistula (gastric pouch and redundant stomach)
15
Q
Bowel arterial supply
A
- Coelic axis= duodenum
- SMA = jejunum, ileum, ascending (right colic) + transverse colon (middle colic)
- IMA= descending colon (left colic), sigmoid (sigmoid arteries), rectum
*RECTUM HAS DUAL BLOOD SUPPLY
> superior rectal artery (IMA) + inferior and middle rectal arteries (internal iliac artery )
16
Q
Signs of closed loop obstruction
A
> Engorged mesenteric vessels.
Mesenteric edema.
Ascites surrounding the bowel or inter-loop fluid
Wall thickening
Lack of bowel wall enhancement
Pneumatosis intestinalis
17
Q
Indirect vs direct hernia
A
Indirect: COMMONEST, lateral to the inferior epigastric vessels, contents travel with spermatic cord, often into scrotum.
Direct: medial to inferior epigastric vessels, weak anterior abdo wall The hernia contents do not go into the scrotum.
Obturator hernia: between pectineus and obturator muscles.
Femoral hernia: protrudes into femoral canal, posterior + inferior to inguinal ligament, differentiated from an inguinal hernia > compress adjacent femoral vein
Spigelian hernia: lateral ventral wall, rectus abdominis and lateral oblique muscles)
18
Q
Coeliacs
A
NORMAL= jejunum has more + closer together folds compared to the ileum.
>Celiac disease=loss of jejunal folds due to villous atrophy REVERSAL OF PATTERN
CT: dilated, fluid-filled bowel loops, often with intra- luminal flocculations of enteric contrast.
Can get t CELL LYMPHOMA
Penumatosis intestinalis
splenic atrophy
Low attentuation mesenteric nodes
19
Q
Scleroderma small bowel findings
A
Dikated duodenum + jejunum
sacculations on antimesenteric border
hidebound bowel due to increased thin bowel folds stacked together.
20
Q
INTRA VS EXTRAPERITONEAL STRUCTURES
A
Retroperitoneal= ascending and descending colon, lower third rectum
INTRAPERITONEAL = transverse + sigmoid , upper- mid rectum
21
Q
Colitis
A
ASCENDING COLON: Yersinia, Salmonella+ colonic TB (Yersinia + TB like TI)
TB > ileocecal valve,desmoplastic reaction, mimics Crohn’s disease.
SIGMOID COLON= SHIGELLA
CMV- ileocolic (also like caecum)
HSV= proctitis
TB
>circumferential wall thickening of TI and caecum INVOLVES CAECUM > TI differentiate from Crohns
>asymmetric thickening of ileocaecal valve
>low attentuation lymphadenopathy
- E. coli, CMV, and C. difficile colitis = pancolitis.
22
Q
Polyposis syndromes
A
- FAP: adenoma polyps, 100% chance increased risk cancer
-Gardner = adenoma polyps periampullary tumour, Desmoid tumors, Osteomas, Papillary thyroid cancer, Epidermoid cysts DOPE - Turcot= FAP variant, Turcot syndrome is another variant of FAP> (gliomas, medulloblastomas)
- HNPCC (Lynch): COLORECTAL ADENOMA, assoc with other cancers- endometrial, gastric, small bowel, liver, biliary, renal
- Peutz Jeghers: hamartomatous lesions SMALL BOWEL (JEJ), assoc: cervical cancer- adenoma malignum, ovary/thyroid/breast/ pancreas
- Cowden syndrome, hamartamtous polyps in GI tract (rectosigmoid) + skin, assoc: thyroid cancer (usually follicular), skin, oral, breast + uterine
-Cronkite Canda- NOT GENETIC, polyps through tract, + Cutaneous manifestations - abnormal skin pigmentation, alopecia, nail dystrophy
23
Q
Mesentery lesions
A
- CARCINOID: usually intraluminal but can spread to mesentery- DISTAL ILEUM, enhancing soft-tissue mass + radiating linear bands extending into the mesenteric fat (desmoplastic reaction). Calc common, MIBG/ Octreotide scans
-DESMOID: Gardners, post op/ PP, isoattenuating to muscle, can have necrosis, desmoplastic reaction
-SCLEROSING MESENTERITIS- mass-like area of heterogeneously increased fat attenuation which may displace loops of bowel. Calcifications may be present FAT HALO- fat immediately adjacent to vessels= spared
24
Q
Omental infarct
A
idiopathic = RLQ medial to cecum/ascending colon
secondary form = site of initial insult.
* CT = circumscribed area of fat stranding, usually large (>5 cm), +/-swirling of omental vessels + hyperdense peripheral halo.
25
Desmoid tumours
- abdominal wall, root of mesentery, retroperitoneum
- FAP (DOPE)/ post surgery
- US: homogeneously hypoechoic, similar appearance to muscle +/- COLOUR DOPPLER
- CT: homogeneously or focally hyperattenuating, enhancing, low T1 and t2
- Ill-defined mesenteric infiltration with small bowel tethering (giving a ‘whorled’ appearance) ▸ this occurs prior to the development of an overt mass ▸ it can cause ureteric or small bowel obstruction
CF sclerosing mesenteritis- more central at root of mesentery
26
Whipples
>Tropheryma whippelii
> Diffuse micronodules "sandlike" in jejunum, thickened folds
> LOW DENSITY NODES
> polyarthritis
27
Hameachromatosis
LOW T2
Primary= pancreas
Secondary = spleen (RES)
CT= increased density
28
Wilsons
Leads to cirrhosis
Increased density on CT
HYPERATTENUATING LIVER
-Iron overload
-Meds (amiodarone, gold, methotrexate).
Wilson disease (Copper overload).
Glycogen excess.
29
Amyloid- GI manifestations
Low density liver= CT
HIGH T1
BARIUM
● Uniform fold thickening or more focal nodular pattern of 5–10 mm nodules.
● Thickened valvulae and mucose.
● Bowel dilatation
● Mural thickening
30
Criteria for LIRADS assignment
Major criteria for HCC:
* Arterial enhancement.
* Non-peripheral washout on PV / delayed phases.
* Enhancing capsule/pseudocapsule seen PV or delayed phases.
* Threshold growth with diameter increase of >50% in <6 months.
Ancillary findings: non-enhancing capsule, nodule-in-nodule architecture, mosaic architecture, fat in mass, blood products
31
Fibrolamellar HCC
Young patients, no cirrhosis, normal AFP
>large, heterogeneous liver mass
>arterial enhancement
+ scar shows persistent enhancement on delayed imaging
CAN HAVE CALC
scar= hypointense on T1 + T2, DOES NOT TAKE UP SULFUR COLLOID, Gallium avid
*CF: FNH= T2 hyperintense scar that enhances late, takes up sulfur colloid
Capsular retraction in 10%*
> CF HCC- fibrolamellar= NO capsule, although may be pseudocapsule
32
HCC
- Hepatic artery supply
- Delayed enhancing rim in pseudpcapsule = specific sign
- most commonly invades portal vein ? hepatic veins
- can have peripheral halo of hypoechogenicity
- C+ post-SPIO (iron oxide): increases sensitivity in diagnosing small HCCs
- FDG PET assesses extra organ disease
33
Liver mets vascularity
HYPOVASCULAR
Breast. Pancreas. Lung. Lymphoma.
HYPERVASCULAR
Melanoma. RCC. Carcinoid /Choriocarcinoma. Thyroid.
CALCIFIED
Mucinous cancers (colon, gastric, ovarian). Osteosarcoma.
Treated lymphoma.
CYSTIC METS
Ovarian cystadenocarcinoma. GI sarcoma.
Liver mets on US: hypoechoic rim producing target sign
34
Capsular retraction
Mass-forming cholangiocarcinoma.
Fibrolamellar HCC
Epithelioid hemangioendothelioma.
Pseudocirrhosis (macronodular liver contour with capsular retraction due to treated metastases).
Confluent hepatic fibrosis (wedge-shaped fibrosis that may be seen in cirrhosis).
35
Hemangioma
-commonest benign liver mass
-pathognomonic =peripheral discontinuous progressive nodular enhancement
-giant haemangioma can have cystic non enhancing central area
- US - hypoechoic halo should never be seen 0 think hyperechoic HCC
Assoc: hereditary haemorrhagic telangiectasia, Kasabach-Merritt syndrome (GIANT)
*GIANT- heterogenous appearance, may not completely enhance, can have central scar
*FLASH FILLING- hyperehcoic, <2cm, quick, intense and homogeneous enhancement of the lesion in the arterial phase and retains contrast CF HCC, hypervascular mets
36
FNH
- commoner women
- 15% have central scar
- NO CAPSULE
- EARLY ARTERIAL ENHANCEMENT AND ISO ON DELAYED IMAGING
- takes up hepatic agents and sulfur colloid, bile ducts seen on HIDA
- retained Eovist enhancement iso- or HYPERINTENSE relative to liver in HEPATOBILIARY PHASE (20 mins) The central scar = delayed enhancement with extracellular contrast agents (such as Gadavist), but will not enhance with Eovist
- CT: scar enhances late
-US : spoke wheel central scar on doppler ON ARTERIAL PHASE
37
Adenoma
- women on COCP/ men on steroids
- no bile ducts therefore -ve on HIDA
- do not take up sulfur colloid
>HYPOINTENSE on hepatobiliary phase (20 mins after injection) due to reduced uptake of Eovist
- high bleeding risk, resected when >5cm
- hypervascular, ARTERIAL ENHANCEMENT, ISO ON DELATED IMAGING, can have fibrous pseudocapsule with delayed enhancement
- can contain fat- HIGH ON T1
38
Amoebic abscess
Entamoeba histolytica, dome right lobe of liver
irregular margins + multiple echogenic nodules
Little enhancement
39
Liver trauma grading
* Grade I: Subcapsular hematoma <10% liver surface. Superficial laceration <1 cm deep.
* Grade II: Subcapsular hematoma 10–50% liver surface. Intraparenchymal hematoma <10 cm in size. Laceration 1–3 cm deep.
* Grade III: Subcapsular hematoma >50% liver surface. Ruptured subcapsular/intraparenchymal hematoma. Laceration >3 cm deep.
Any intraparenchymal vascular injury (i.e., pseudoaneurysm or AV fistula) or contained active bleeding.
* Grade IV: Laceration involving 25–75% of one hepatic lobe. Extraparenchymal extension of active bleeding into peritoneum.
* Grade V: Laceration / destruction >75% of one hepatic lobe. Injury to retrohepatic IVC or central hepatic veins.
40
Liver transplant candidates HCC
Single tumor <5 cm or up to three tumors, each with diameter <3 cm. No extrahepatic involvement.
No major vascular involvement.
*Hepatic artery thrombosis= commonest vascular injury
*Bile duct constriction= commonest biliary injury
> PTLD- mass that can look like anything
41
LIRADS Features
1. Arterial phase hyperenhancement
2. 2. Non-peripheral washout
3. Capsule - Smooth, uniform border
4. Size
5. Threshold growth - increase in size >50% within 6 months time
42
Portal HTN features
Biphasic / reversed flow
Velocity <16cm/s
Dilated portal vein >13mm
Splenomegaly.
Gamna-Gandy bodies- splenic microhemorrhage
Varices.
Portosystemic shunts (gastroesophageal, paraumbilical, splenorenal)
43
TIPS occlusion
Occluded TIPS:
no blood flow through TIPS RPV and LPV have “re-reversed”:
now have hepatopetal flow (away from TIPS)
MPV has hepatopetal flow (towards occluded TIPS)
44
Adenomyomatosis
MRI=focal, bubbly T2 hyperintense thickening along the gallbladder fundus
45
BG Polyps
- sessile = suspicious
- consider removal if >10mm
46
Diffuse GB wall thickening
>Fluid-overload/edematous states:
Cirrhosis: Hypoalbuminemia
CHF, Protein-wasting nephropathy.
* Inflammatory/infectious:
Cholecystitis, Hepatitis.Pancreatitis.
* Infiltrative neoplastic disease: GB Ca, mets
* Post-prandial state.
47
Choledochal cysts
- Type I = fusiform dilation CBD
- Type 2 extrahepatic saccular dilatation
- Type 3 = dilation of CBD into duodenum
- Type IV = intra + extrahepatic
- Type 5= Carolis = intrahepatic duct dilation ASSOC: PCKD
Caroli syndrome= disease + hepatic fibrosis. *central-dot sign
48
Biliary tree pathology
PSC: beaded appearance intra + extrahepatic ducts, Assoc: UC, cirrhosis, cholangiocarcinoma
*cirrhotic pattern = central regenerative hypertrophy
PBC: destroys small INTRAHEPATIC bile ducts, lace like pattern fibrosis, increased risk HCC, assoc: AMA antibodies
AIDS cholangiopathy: similar to SPC with strictures >2cm, lacks saccular dilation, Cryptosporidium, PAPILLARY STENOSIS
Recurrent pyogenic cholangitis (oriental cholangiohepatitis)- parasite: Clonorchis sinensis, SE Asia, 1) Pneumobilia.
2) Lamellated bile duct filling defects.
3) Intra+extrahepatic dilation/ strictures.
49
Biliary cystadenoma
- NO communication with biliary tree
- septated, large
- degeneration to biliary cystadenocarcinoma (solid and nodular enhancing component ) therefore RESECTED
US
●● Multilocular cystic lesion in right lobe.
●● Internal septations.
●● Mural papillary projections = characteristic.
●● Septations, cyst walls and solid components may enhance (unlike simple cysts).
50
Cholangiocarcinoma
1.Mass forming
2. Periductal cholangiocarcinoma: confluence of R+L hepatic biliary ducts *Klatskin tumor*-“shouldering / abrupt tapering” on MRCP
3.Intraductal
Intrahepatic duct dilation + capsular retraction =, DELAYED ENHANCEMENT + peripheral washout, encases the PV, painless jaundice
RF: Choledochal cyst(s).
PSC, FAP, Clonorchis sinensis infection. Thorium dioxide
51
GB Ca
scirrhous infiltrating mass that invades GB wall into liver (less commonly polypoid mass)
52
Polyps
*Anadenoma - commonest rectosigmoid
1. tubular(65%), 2.
tubulovillous(25%) 3. villous (10%) ▸ villous = higher risk
■ Pedunculated: considered cured if resected and tumour confined to stalk
■ Sessile: broad-based (base must be >x2 height) ▸ roughly hemispheric ▸ intermediate risk of invasive malignancy
■ Flat : height that no more than x2 height of adjacent mucosa ▸ * flat depressed lesions = higher risk for invasive cancer
SIZE= BIGGEST INDICATOR OF MALIGNANCY
Barium findings:
Juvenile polyps: smooth, pedunculated, thin stalk
*Post inflammatory: filiform configuration ( finger-like projections)
*Villous: lace-like or mosaic appearance ▸ some may present flat, nodular, carpet-like growth
53
Radiation enteritis vs typhilits
- Radiation enteritis: ulceration, submucosal oedema, becomes fibrotic, strictures, loops become fixed in position due to desmoplastic reaction
*spastic bowel loops with luminal narrowing + oedema of mucosal folds
*chronic=
thickening of bowel wall + folds due to oedema / fibrosis
“stack of coins appearance” enlarged smooth, parallel mucosal folds
- Typhylitis: IMMUNOCOMPROMISED, thickened >4mm and markedly oedematous
54
Colitis location
Diffuse involvement of whole colon- CMV and E Coli
Right sided colon- Salmonella , Yersinia
Left sided colon- Schistosomiasis
Sigmoid = Shigella
Rectosigmoid colon- Gonorrhoea, herpes, Chlamydia (LGV)
55
Kaposi sarcoma
- commonest liver malignancy in those with AIDS
- periportal hyperechoic nodules
CT
●● Enhancing lymph nodes
●● Multiple 5–12–mm, low-attenuation nodules in the liver
●● Skin lesions help to distinguish from fungal microabscesses and multiple
haemangioma (purple)
GALLIUM -VE, THALLIUM +VE
56
Nodules in liver cirrhosis
- Dysplastic- hypervascular, NO RESTRICTED DIFFUSION, large and less
- Regenerative- isointense to liver, multiple, no arterial enhancement
- Sideroblastic- can contain iron
57
Pancreatic tumour
- Solid pseudopapillary tumour: large mass with heterogeneous solid/cystic areas. Hemorrhage common,capsule
- Mucinous: mother, large cysts >2cm, <6, body and tail, can have peripheral calc, can have a capsule
- Serous: older women, head of pancreas, stellate enhancing central scar with calc, innumerable tiny cysts, can look like solid mass
- IPMN: Segmental or diffuse dilatation of MPD >5 mm, Cysts >5 mm communicating with the MPD, premalignant, increased risk of adeno
58
Pancreatic injury
Direct signs = laceration, focal pancreatic enlargement,pancreatic hematoma.
Indirect = peripancreatic fluid (lesser sac or interdigitating between pancreas and spleen), induration of the peripancreatic fat, and thickening of left anterior renal fascia.
59
Primovist
HPB specific- taken up by hepatocytes
> on hepatibiliary imaging (20 mins) enhancement anywhere where there is bile (biliary tree, GB, possibly into the duodenum etc, and any bile leaks)
FNH takes up Primovist> contains hepatocytes - uptake on delayed imaging
Adenoma DOES NOT ENHANCE with Primovist
60
Oesophageal indentation
Anterior = aberrant left pulmonary artery
Posterior=
- right sided arch with aberrant left subclavian artery
- left sided arch with an aberrant right sided subclavian artery
- double aortic arch (anterior trachea indentation)
61
Rectal drainage
Dentate line : divides upper two-thirds and the lower third of the anal canal
ABOVE: internal iliac lymph nodes.
Below: superficial inguinal lymph
62
Hepato veno occlusive disease
Hepatic congestion develops as a consequence of fibrosis to the venules within the liver
CAUSES: secondary to chemotherapy or bone marrow transplantation
On UC/CT: veins normal size but may have increased pulsatility/ reduced flow
63
Angiodysplasia
- affects ASCENDING COLON + CAECUM
> antimesenteric border, right colic artery
64
Perianal fistula
Inter-sphincteric= 70%
Does not cross the external sphincter, remains medial to it
Trans-sphincteric= 25%
Crosses the external sphincter (as well as the internal one)
Supra-sphincteric= 5%
Courses superiorly over the top of the external sphincter
passes superiorly into the intersphincteric space, and over the top of the puborectalis muscle then descending through the iliococcygeus muscle into the ischiorectal fossa and then skin
Extra-sphincteric <1%
Begins higher up in the rectum, avoids both sphincters, exits the pelvis through the levator ani complex and into the ischiorectal fossa
65
Plummer Vinson
OESOPHAGEAL WEBS, iron deficiency anaemia, glossitis/ stomatitis, dysphagia, thyroid disorders
66
Boerrhave vs Mallory Weiss
- Boerrhave: rupture of the oesophagus> pneumomediatinum, left pleural effusion
- Malloey Weiss tear- laceration in distal esophagus involving GOJ, NOT TRANSMURAL
67
Atrophic gastitis
- loss of the rugal folds (± the areae gastricae)
- ▸ a tubular and featureless narrowed stomach
- assoc: pernicious anaemia/ B12 deficiency
- increased risk: polyps, gastric ca
68
Small bowel infection
Giardiasis ▸ contaminated drinking water. THICKENED VALVULAR CONNIVENTES - duodenum + proximal jejunum ▸ nodularity, JEJUNAL SPASM
CMV- AIDS, Diffuse small bowel NARROWING, ulcerations + fold effacement *affects caecum*▸ can be oesophagitis, gastritis or colitis
Cryptosporidium: Small bowel DILATATION ▸ thickened small bowel folds
Yersinia ▸ tortuous, thickened mucosal folds with small discrete nodular filling defects of lymphoid hyperplasia ▸ there can be mural thickening *TERMINAL ILEUM*
69
GIST
stomach > small intestine,
Ulceration if it outstrips its blood supply (>2 cm)
* ‘Bulls-eye’ / ‘target’ lesion
*soft tissue density mass, can have central necrosis/ fluid-fluid level
-well-circumscribed submucosal mass extending exophytically from the GI tract ▸ coarse calc ▸ and may obstruct pylorus or duodenum ▸ hypo- or hypervascular
* lymphadenoapthy rare
* distant mets= liver, peritoneum
Assoc: NF1
Carney’s triad:
■ Multiple GISTs + extra-adrenal paraganglioma + a pulmonary chondroma
FDG PET avid
70
Pseudomembranous colitis
- pancolitis/ left sided
- involves rectum
- thumbprinting / mucosal thickening
- ACCORDION SIGN:contrast between thickened low attenuation mucosal folds
- less inflammatory stranding> IBD
Can have ascites
71
Reflux esophagitis
- longitdunal scarring, fixed transverse folds with barium in between, stepladder appearance
72
Criccopharyngeus impression
- Anterior indentation at C5
73
Hypertrophic gastritis
- Menetriers
- loss of protein
- increased folds in the fundus + body, spares antrum *GREATER CURVATURE*
prominent areae gastricae
74
Amoebic abscess
- risk of pericardial/ peritoneal rupture
"chocolate cyst" - can look like normal abscess
Traveller
Right lobe
Thick walled
PAIN
75
MEN types
MEN 1:
* Parathyroid Hyperplasia (90%),
* Pituitary Adenoma,
* Pancreatic Tumor (Gastrinoma= commonest)
MEN 2:
* Medullary Thyroid Cancer (100%) * Parathyroid hyperplasia,
* Pheochromocytoma (33%)
MEN 2b:
* Medullary Thyroid Cancer (80%) * Pheochromocytoma (50%)
* Mucosal Neuroma,
* Marfanoid Body Habitus
76
Pancreatic divisum
- dorsal portion (majority) drained through the smaller duct of Santorini into minor papilla > recurrent pancreatitis
*crossing duct sign = CBD crossing over main duct to join duct of Wirsung.
*Common channel syndrome= septum absent, at major papilla allowing reflux between CBD/ pancreatic duct
>predispose to choledochal webs, choledochal cysts, pancreatitis, cholangio
77
Pancreatic collections
< 4 weeks Acute peripancreatic fluid collection: Non-encapsulated fluid collection.
> 4 weeks Pseudocyst: Encapsulated fluid collection= fluid enclosed by a fibrous wall lacking an epithelial lining.
<4 weeks: Acute necrotic collection: Non-encapsulated collection containing heterogeneous material.
> 4weeks: Walled-off necrosis: Encapsulated heterogeneous, non-liquified collection with thick walls.
78
Autoimmune pancreatitis
diffuse, sausage-like enlargement of the pancreas with loss of lobulation, normal pancreatic duct
79
Acinar cell carcinoma
-agressive, seen in ledelry males
-lipase hypersecretion syndrome: subcutaneous fat necrosis, bone infarcts causing polyarthralgias, and eosinophilia.
80
Pancreatic endocrine tumour
Insulinoma= commonest
Gastrinoma= ZE syndrome, MEN 1 *location= between cystic duct and CBD, the duodenum inferiorly, and the neck/body of the pancreas medially.
>Glucagonoma = migratory rash, diabetes, and glossitis. very malignant behaviour, Prognosis is poor.
* VIPoma- profuse watery diarrhea and hypokalemia.
81
Pancreatic lymphoma
homogeneously, diffusely enlarged gland without ductal dilatation, with associated lymphadenopathy. More aggressive types of lymphoma may show heterogeneity/central necrosis.
82
Splenic mets
Breast, lung, ovarian, and melanoma. Ovarian cancer and melanoma typically cause cystic metastasis.
*Angiosarcoma- arge, heterogeneous mass that may completely replace the normal spleen. Enhancement is variable and heterogeneous
83
Gaucher disease
Erlenmeyer flask deformity of the distal femurs, femoral head AVN, H-shaped vertebral bodies
+ huge spleen
84
Hernias
Femoral
Inferolateral to the pubic tubercle and medial to the femoral vein
More common in women
Direct inguinal
Superolateral to the pubic tubercle, medial to the inferior epigastric vein
Through Hesselbach triangle
Indirect inguinal
Superolateral to the pubic tubercle and lateral to the inferior epigastric vein
Most common abdominal hernia
Obturator
Between pectineus and obturator externus muscles, through the obturator foramen
Rare
Spigelian
Inferolateral abdominal wall defect, lateral to the rectus abdominus muscle
May be congenital and associated with cryptorchidism
85
Lymph node drainage
Coeliac lymph nodes
Stomach, Most of the duodenum
Liver and biliary tree
Pancreas
Spleen
Superior mesenteric lymph nodes
Part of the duodenum
Jejunum and ileum
Caecum and appendix
Ascending colon
Transverse colon
Inferior mesenteric lymph nodes
Descending colon
Sigmoid colon
Upper rectum
86
Modic endplate changes
type 1: Low T1 High T2, endplate enhancement, disc signal should always be low > high in disctitis
87
Renal AML
>4cm- consider embolisation as can bleed
88
Middle + inferior rectal vein drainage
- directly into pelvic veins - IVC, bypasses portal venus system
89
Gastric lymphoma > Ca
- more extensive thickening
- no fat invasion
- duodenal involvement
- gastric outlet obstruction
- larger nodes which extend below renal hilum
90
Paeds reflux
I. Ureters only
II. Reaches pelvis, no dilatation
III. Mild dilatation but no calcyeal clubbing
IV. Moderate dilatation with calcyeal clubbing
V. Severe dilatation with tortuous ureter
91
Amyloidosis
thickened mucosal folds duodenum > stomach
92
Whipples
thickened valvulae conniventes duodenum + proximal jejunum + low density (fat) nodes
"sand like nodules jejunum"
93
Epiploic appendagitis
ANTERIOR TO SIGMOID + CAECUM
peripheral enhancement
CF omental infarction- low density + affects right side
94
Mesenteric panniculitis
●Heterogeneous mass at mesenteric root, which envelops vessels
●jejunal mesentery.
●low-attenuation halo of fat.
95
Liver laceration
* Grade I:
Subcapsular hematoma <10% . <1 cm deep.
* Grade II:
Hematoma 10–50% Intraparenchymal hematoma <10 cm Laceration 1–3 cm deep.
* Grade III:
Hematoma >50%
Ruptured subcapsular /intraparenchymal hematoma.
Laceration >3 cm
Any intraparenchymal vascular injury / contained active bleeding.
* Grade IV:
Lac 25–75% one lobe
ACTIVE bleeding into peritoneum.
* Grade V:
Laceration or destruction >75% of one hepatic lobe.
Injured retrohepatic IVC or central hepatic veins.
96
Liver transplant complications
Criteria:
Single tumor <5 cm
Up to 3 tumors, <3 cm.
No extrahepatic involvement.
No major vascular involvement.
- Hepatic artery stenosis
- Biliary stricture
- PTLD
97
GIST
- usually benign but can be malignant
> NF 1, Carney triad
* Extra-Adrenal Pheo, GIST, and Pulmonary hamartoma)
Stomach > small bowel
●● Smooth, large solid mass submucosal sometimes with cystic areas and a sizeable exophytic component.
●● Peripheral enhancement—large vessels or vascular blush common.
●● Central low attenuation > necrosis, haemorrhage and cyst formation.
98
Pancreas divisum
Minor papilla drains DORSAL duct (body + tail)
99
Hepatoblastoma
Kids <5yo
Increased AFP, CALC, low T1, heterogenous enhancement
100
Haemochromatosis
CT: increased density
MRI: low signal T1+T2
Diabetes, skin hyperpigmentation
101
Amyloid
CT: LOW ATTENUATION
102
Wilsons disease
CT: Increased density
Hepatomegaly + cirrhosis
103
Mastocytosis
Bone sclerosis + hepatosplenomegaly + lymphadenopathy +/- ascites
104
Plummer Vinson Synrome
Webs+ iron deficiency anaemia + glossitis + dysphagia + thyroid disorders
105
Oesophageal spasm
High manometry pressures
Numerous tertiary contractions
106
Radiation enteritis
Ileum= most commonly affected
increased attenuation of mesentery
107
Tertiary contractions
Non propulsive, disordered, yo yo, doesn't clear oesophagus
108
Hyperplastic polyps
Found in body/ fundus
109
Whipples procedure
*pancreaticoduodenectomy
Gastrojej
Choledocojej/ hepaticojej
Pancreticojej
Comps:
Blind loop syndrome- afferent loop partially obstructs + overdistends
110
jejunum features
Thicker valvular conniventes + wall
Larger diameter
111
Chagas disease
Diffuse esophageal dilation + megacolon + cardiomegaly
112
Carcinoid commonest location
Appendix, ileum
Can also be in mesentery
113
MRCP mri property
Heavily T2 weighted
114
What is spleen SI similar to?
Muscle
In hemochromatosis- less than muscle
115
Fat containing HCC
- Less vessels therefore arterial enhancement = less
116
Management of esophageal rupture
PUT IN LEFT LATERAL POSITION
117
Commonest cause of ischemic colitis?
SMA clot
118
Most specific sign of mesenteric injury?
Contrast extravastion
119
Pancreatic cancer CI to resection
Mass >3cm
Mets
Involvement of coeliac/ SMA/ gastroduodenal/ SMV + portal vein
Involvemenet of >180
120
Adenoma
Arterial hyperenhancement, delayed washout
can have calc/ hemorrhage
Can have scar
121
FNH
Arterial hyperenhancement
Hypointense scar on arterial that enhances on delayed
122
Gastri lymphoma > adeno
Distal stomach
Distentability
fat planes presrved
Bulky lymphadenopathy below renal hilum
123
Amyloid findings in bowel
Small bowel dilation
Jejunisation of ileum
124
HCC with HPB agents
normally arterially enhancing and quick washout
*FNH= RETAINS CONTRASTR PV PHASE*
but
well-differentiated HCC can have absent APHE and appear hypointense on hepatobiliary phase
125
Dysplastic liver nodule
single, or few nodules
can be hypo-, iso-, or hyperdense on CT
early arterial enhancement without washout on later phases
iso- to hypointense on T2WI
no restricted diffusion
126
Regenerative liver nodule
numerous (thousands) micro (< 3 mm) nodules, but can be single/few macro (> 3 mm) or giant (> 5 mm) nodules
invisible on non-contrast CT, except for siderotic nodules which appear hyperdense
siderotic nodules show blooming artifact on T2*
do not enhance, or enhances similar to or lower than the liver parenchyma
no arterial hyperenhancement
HIGH T1
HCC in regernative nodules - hyperenhancing
127
Hydatid cyst liver
Eosinophilia
Satellite nodules
Daughter cysts
Double rim sing- echogenic lines of pericyst + endocyst
Floating membrane/ water lily sign
128
Choledochal cyst
Photopenic area HIDA
Dilated CBD
No small bowel uptake
129
Pancreatic cancer mri
low T1
Variable T2
Hypoenahncing in arterial phase
130
Massive splenomegaly
CML
Gauchers
Malaria
Myelofibrosis
Shisto
131
Klatskin tumour
FDG avid
132
MAI
Affects ileum + jejunum
133
Tailgut cyst
Pre sarcal, multilocular
large= pain, bleeding, constopation
duplication cyst = unilocular
134
Bullseye sign barium meal
Metastatic melanoma = common neoplastic cause.
●● Breast
●● Lung
Other causes:
●● Gastrointestinal stromal tumour
●● Lymphoma
●● Kaposi’s sarcoma
●● Neurofibromatosis (NF)
●● Pancreatic rests
135
Amoeba bowel findings
R COLON + CAECUM
Segmental/ diffuse colitis/ulcers
can cause stricturing
136
Interstitial vs necrotic pancreatitis
necrotic = decreased enhancement
137
Eosinophilic gastritis
Involes stomach, small bowel
*ANTRUM involved*
138
When can you see a GB on a HIDA scan?
Liver seen within 5 mins
GB After 20 minutes
> Acute cholecystitis- will not see GB by 90 mins *rim sign*
>Chronic- can be normal, or delayed filling- seen at 4 hours, GBEF <35% suggests chronic cholecystitis
> Biliary obstruction- cannot see biliary tree, no bowel uptake
To detect biliary leak- put in right decub position > extraluminal contrast. Look in right paracolic gutter/ reappearing liver sign
139
Yersinia findings
Involves TERMINAL ILEUM
Thickened valvular conniventes
Nodular filling defects
140
False +ve HIDA
IE. can see GB but there is acute chole
Acalculous cholecystitis + patent cystic duct.
Duodenal diverticulum simulating the gallbladder;
(lateral view would differentiate)
Choledochal cyst
Right extrarenal pelvis in jaundiced patients with increased renal excretion of tracer.
141
Cyclosporin toxicity
Normal perfusion
Delayed excretion
142
Perineal tear
first degree: laceration of vaginal mucosa or perineal skin only
second degree: involvement of the perineal muscles without the anal sphincter
third degree: tear of the anal sphincter muscles
3a: <50% thickness of external anal sphincter (EAS)
3b: >50% thickness of EAS
3c: torn EAS and internal anal sphincter (IAS)
fourth degree: a third degree tear extending to anal mucosa
143
Epitheolid hemangioendothelioma
US
●● Solid, hypoechoic lesions CT
●● Multiple slow-growing, peripheral, low-density foci that may coalesce.
●● Punctuate calcification.
●● Prominent rim enhancement with contrast
●● Capsular retraction
MRI
●● Lesions are non-specific, low signal on T1, high on T2.
144
Splenic abscess
Immunocompromised
Candida
Centrally necrotic nidus
"Wheel within wheel"
145
Glycogenic acanthosis
Elderly, asymptomatic
yellow/ white plaques, Candida mimic
146
Gastric banding complications
1. Stomal stenosis= too tight - vomiting
2. Band erosion- causes necrosis > leak
3. Slippage- angle too flat> obstruction
147
Infiltrative HCC
multiple nodules
T1+C shows minimal arterial enhancement, hypoenhancement or isoenhancement
a miliary pattern of enhancement has also been reported
venous and delayed phases
washout remains a feature of infiltrative HCC, although it may be more heterogeneous or irregular than its nodular counterpart
washout may be absent in up to 50% of cases, in contrast to 33% of nodular hepatocellular carcinoma 3
a reticular appearance of the tumour can be seen, possibly related to fibrosis
148
Splenic trauma
* Grade I:
Subcapsular hematoma <10% spleen surface.
Tear of splenic capsule or superficial laceration <1 cm deep.
* Grade II:
Subcapsular hematoma 10–50% spleen surface. Intraparenchymal hematoma <5 cm in size. Laceration 1–3 cm deep.
* Grade III:
Subcapsular hematoma >50% spleen surface. Ruptured subcapsular/intraparenchymal hematoma. Laceration >3 cm deep.
* Grade IV:
Any intraparenchymal vascular injury (i.e., pseudoaneurysm or AV fistula) or contained active bleeding. Laceration involving central splenic vessels resulting in >25% devascularization.
* Grade V:
Extraparenchymal extension of active bleeding into the peritoneum. Shattered spleen.
149
