ABDO/IR Flashcards
Achalasia is
failure of organised oesophageal peristalsis causing impaired relaxation of the lower sphincter resulting in stasis and dilatation
due to loss/destruction of neurones in the auerbach/myenteric plexus
Achalasia imaging
short segment 3ish cm
xr
convex opacity overlapping mediastinum
air fludi level
small absent gastric bubble
displaced trachea on lateral
FLUORO
bird beak/rat tail
dilatation
tram track
incomplete relaxation
pooling/stasis
tertiary contractions
failure of clearance
Achalasia ddx
central/peripheral neuropathy
scleroderma
malignancy
stricture
chagas disease
non spec dysmotility
diffuse spasm
presbyoesophagus
Chagas disease is, and manifestations
tropical parasite infection (trypanosomiasis)
Cardiac
- myocarditis
- dilated cardiomyopathy
GI
- dysmotility and megaoesophagus
- megaduodenum and small bowel
- megacolon
GU
- megaureter
CNS
- meningoencephalitis
- chagoma
Presbyoesophagus is
manigestations of degenerating motor function in the aging oesophagus
Diffuse oesophageal spasm is
a motility disorder of the opesopahgus. may appear as a corkscrew esophagus
nutcracker oesopahgus is
a motility disorder, uisually normal swallow study
Schatzki ring is
a symptomatic narrow b ring occuring in the distal oesophagus and usually assoc with a hiatus hernia
Oesophageal web is
a constriction caused by a thin membrane projecting into the oesophagus, typically cervical
Oesophageal stricture aetiology
Upper and middle
- Barrett
- radiation
- caustic ingestion
- congenital
- intramural pseudodiverticulosis
- skin diseases, eg pemphigoid
Distal
- usually in the setting of GORD or
- scleroderma
- post NGT
- zollinger ellison
- post gastrectomy
Barrets oesophagus is and imaging
metaplasia of the oesophagus, a precursor for adenocarcinoma
imaging
- signs of reflux oesophagitis
- reflux
- long stricture
- large deep ulcer
- reticular mucosal pattern
- thickened folds
Oesophagitis causes
Infective
- HIV
- CMV
- Herpes
- Candida
Non infective
- drugs
- reflux
- corrosive
- idiopathic eosinophilic
- radiation
Oesophagitis imaging
mucosal irreg
erosions and ulcers
abnormal motility
thickened folds
limited distensibility
strictures
pseudodiverticulosis
small ulcers
- reflux
- herpes
- radiation
- drug induced
large ulcers
- cmv
- hiv
- carcinoma
Corrosive oesophagitis imaging
acute
- oedema
- ulceration
- sloughing
- dilatation
- atony
chronic
- single long or multiple stricutres
Idiopathic oesinophilic oesophagitis is
an inflammatory disease characterised by eosiniophilia of the oesophagfus layers
imaaing
- ringed oesophagus
- may coexist with longer stricutres
feline oesophagus is
transient transverse bands seen in the mid and lower oesophagus - almost always associated with reflux
Oesophageal carcinoma subtypes
Squamous (80%)
Adeno (20ish)
- mostly related to barretts, lower GOJ
Other
- mucoepidermoid
- adenoid cystic
- spindle cell
- leiomyosarcoma
- rhabdomyosarcoma
- fibrosarcoma
- lymphoma
Macroscopic
- polypoid
- ulcerating
- infiltrating
- superficial spreading
Oesophageal carcinoma imaging
XR
- wide azygooesophageal recess
- thick posterior stripe/right paratracheal striple
- tracheal deviation
- retrocardiac/posterior mediastinal mass
- air fludi level
- mass in gastric bubble (Kirklin)
Fluoro
- irregular stricture
- dilatation and hold up
- shouldering
CT
- eccentric wall thickneing >5mm
- perioesohpageal stransing/soft tissue
- dilated
- tracheobronchial invasion
- aortic invasion
Oesophageal leiomyoma is
a benign smooth muscle neoplasm of the oesophagus
imaging
- discrete ovoid mass, well outlined
- obtuse angles
- intramural, smooth
- calcifications are pathognomonic
- moderate enhancement
- no invasion
Oesophageal fibrovascular polyps are
benign intraluminal submucosal pedunculated tumours, usually occuring in the upper third of the oesophagus at the level of the upper sphincter
Peptic ulcer disease imaging
pocket of barium filling crater
- post bulbar; zollinger ellison
oedematous collar of swollen mucosa
radiating folds of mucosa away from ulcer
Acute gastritis causes and imaging
aetiology
- infection; hpylori
- systemic illness
- nsaids
- autoimmune
- caustic
- immunosuppression
- eosinophilic
imaging
- gastric wall oedema
- halo sign; enhancing mucosa
Atrophic gastritis imaging
decreased/absent fundal folds
narrow tubular stomach
small absent areae gastricae
linitis plastica - usually nodular
GISTs are
the most common mesenchymal tumours of the GI tract
c KIT histopath
assoc
- carney triad
- NF1
- carney striakis
GIST imaging
Location
- stoamch
- SI
- anorectum
- colon
- oesophagus (uncommon)
- extra GI - mesentery, omentu, retroperitoneum (uncom)
CT
- soft tissue, central necrosis
- often exophytic
- screscent ulceration with air fluid level (torricelli bernoulli sign)
- peripheral enhancment
- calcs uncommon
MR
variable due to necrosis, haemorrhage, cystic change
Concerning; exogastric growth, >5cm, central necrosis and extension to other organs
Gastric adenocarcinoma imaging
Fluoro
Early
- elevated, superficial or shallow lesions
Advanced
- polypoid
- ulcerating
CT
- polypoid +/- ulceration
- focal wall thickening
- ulceration
- infiltrating
Menetrier disease is
a rare idiopathic hypertrophic gastropathy
present with acholhydria, hypoproteinaemia and oedema. typically fundal region.
fluoro
- enlarged and tortuous folds in the fundus and body, sparing the antrum
- diluted barium due to mucus hypersecretion
CT
- thickened rugae, resembling convolutions of brain
- wall thickness normal between folds
Zollinger ellison syndrome is
a clinical syndrome secondary to a gastrinoma
secrete gastrin, hypersecretion of gastric acid
leads to diarrhea, gastritis, GORD and PUD
assoc with MEN 1
Zollinger ellison syndorme imaging
Fluoro
- thickened rugael folds
- multinodular gastric contour
- erosions and ulcers
CT
- thickened rugal folds
- multiple gastric nodules
ddx
- other gastritises
- gastric lymphoma
- menetrier
- outlet obstruction
Inguinal hernia types
Indirect
- lateral to inferior epigastric vessels
- deep inguinal ring
- anterior to spermatic cord in males
- follows round lig in females
Direct
- medial to inferior epigastric vessels
- through a defect in hesselbachs triangle
- weakness in the fascial floor of the inguinal canal
- inguinal canal is usually compressed/displaced (lateral crescent sign)
Meckels diverticulum is
a congenital intestinal diverticulum due to fibrous degeneration of the umbilical end of the vitelline duct that occurs around the dital ileum
Meckels rule of 2
2% population
2 inches
2 feet from IC valve
2/3 ectopic mucosa
2 types of ectopic tissue
2% symptomatic
Meckels presentation
Haemorrhage
Obstruction
- adhesion
- luminal
- intussception
- Littres hernia
Inflammation
Perforation
Neoplasm
Meckels imaging
CT
- blind ending small bowel pouch
- antimesenteric side of the distal ileum
- can invert and cause an internal polypoid lesion
NM
- pertechnetate
- only if gastric mucosa present, mucin secreting cells-
Duodenal diverticulum types and complications
Can be primary (mucosa) or secondary (entire wall)
Can be periampullary
Can be intraluminal (duodenal web)
Complications
- diverticulitis
- haemorrhage
- perforation
- biliary obstruction (Lemmel symdrome)
Duodenal diverticulum ddx
Periduodenal abscess
Duodenal ulcer
Duodenitis
Head of pancreas cystic lesion
Pseudocyst
Duodenal web is
obstruction at the duodenum due to a membranous web or intraluminal diverticulum. small central aperture, different to atresia
ddx
- duodenal stenosis
- duodenal atresia
Duodenal atresia is and assoc
a congenital malformation fo the duodenum with complete obstruction of the lumen
assoc
- downs
- vacterl
- annular pancreas
- other atresias
Duodenal atresia imaging and ddx
XR
double bubble
- if distal gas, stenosis
US
double bubble
- ?connection, might be a foregut duplication
DDX
- stenosis or web
- malrotation and volvulus
- choledochal cyst
- omental cyst
- duplication cyst
Gastroschisis is
extraabdominal herniation of fetal/neonatal bowel loops into the amniotic cavity through a paraumbilical defect. no surrounding membrane. no strong associations
Gastroschisis imaging
herniated content to right side of cord
small AC
ddx
- omphalocoele
- physiological herniation (before 11 weeks)
Omphalocoele is
congenital midline abdominal wall defect at the base of the umbilical cord insertion
Omphalocoele assocaitions
Chromosomal
Other syndromes
- BW
- pent cantrell
- OEIS
- lethel omph cleft palate
Other anomalies
- CNS, cardiac, GU, skeletal
Omphalocoele imaging
mulitple bowel loops in membrane covered defet
direct cord insertion
small AC
polyhydram
allantoic cyst often present
can rupture
ddx
- pseudoomph
- gastroschisis
- physiological herniation
- limb body wall complex
- umbilical hernia
Polyposis syndromes
Hereditary
- Hereditary nonpolyposis colorectal cancer HNPCC
- Familial adenomatous polyposis syndromes FAPS ( incl, classic,. Gardner, Turcot)
- Bannayan riley ruvalcaba
- Cowden
- Peutz jeghers
- TS
- Juvenile polyposis syndromes
Non hereditary
- Serrated polyposis syndrome
- Cronkite Canada syndrome
- Juvenile polyposis syndrome
Can also be adenomatous or hamartomatous
Adenomatous
- FAPS
- Gardner
- (HNPCC - cancers come from adenomatous polyps)
Hamartomatous
- JPS
- BRR
- Cowden
- Peutz Jegher
- Cronkhite Canada
HNPCC/Lynch syndrome is
an AD condition which predisposes to malignancies, including colorectal. Due to mutations in DNA mistamtch repair (MMR) geners
Cancers
- CRC
- GU (endometrial, ovarian, prostate, urothelial)
- SB
- Gastric
- hepatobiliary
- CNS
Diffuse polyposis is characteristically absent
FAPS is
characterised by presnece of hundreds of adenomatous polyps in the colon, mutation of the tumour suppressor APC gene, though can be MUTYH.
<5mm. rectum typically spared. can have extracolonic (duodenal, gastric) polyps
associations
- CRC
- hepatoblastoma
- extracolonic polyps (stomach, duodenum)
- desmoid tumours
- osteomas
- dental anomalies
- papillary thyroid ca
Variants
- gardners
- attenuated FAP
- familial polyposis colli
Gardner syndrome is
FAP
Multiple osteomas
Epidermal cysts
Fibromatoses
Desmoid tumours
Supernumery deeth, odontomas, dentigerous cysts
Ampullary carcionoma
Papillary thyroid ca
Turcot syndrome is
characterised by multiple colonic polyps and increased risk of colonic and primary brain tumours; commonly medulloblastomas or GBM
APC gene
- CRC by 40
- medulloblastomas
HNPCC gene
- not as much CRC
- GBM
Bannayan Riley Ruvalcaba syndrome is
AD disorder caused by mutation of the PTEN gene
Features
- hamartomatous intestinal polyps, typically terminal ileum and large bowel
- macrocephaly
- lipomatosis
- dermal and deep visceral lipomas
- angiolipomas
- haemangiomata
- speckled penis
- hypotonia
- scoliosis
- pectus
- woman:::: breast ca, MR screening
Cowden syndrome is
caused by mutation of the PTEN gene and characterised by hamartomas throughout the body and increased risk of ca
Features
- mucocutaneous lesions, including trichilemmomas
- GI polyps, large and small bowel
- glyucogenic acnathosis
- thyroid goitres
- fibrocystic breast disease
- testicular lipomatosis
Cancers
- breast
- thyroid
- dysplastic cerebellar gangliocytoma, in assoc with Lhermitte duclos disease
Peutz Jeghers syndrome is
AD polyposis syndrome characterised by
- multiple hamartomatous polyps (SB/jejenum), also colon, stomach
- mucocutaneous melanin pigmentation mouth/fingers/toes
Proliferation of all three layers of the mucosa
Cancers
- CRC, stomach, small intestine
- adenoma malignum
- breast
- pancreas
- ovary sec cord
- uterus
- cervix
- testis (sertolis)
- lung
Serrated polyposis syndrome is
characterised by presence of multiple serrated polyps. heterogenous genetic with BRAF and KRAS most common. CRC in 50%.
Juvenile polyposis sydrome is
hundreds of hamartomatous polyps containing fluid or mucus. SMAD4 and BMPR1A implicated. end up with CRC
Assoc
- malrotation
- meckels
- hydrocephalus
- congenital heart
- mesenteric lymphangioma
- pulm AVM
Cronkhite canada syndrome is
a non neoplastic non hereditary hamartomatous polyposis syndrome characterised by rash, alopecia and watery diarrhea
predominantly stomach, large intestine and small bowel. not assoc with malig.
Infective enteritis overview
Proximal: giarida, stronglyloides
Distal: salmonella, shigella, yersinia
Distal ileum/caecum: TB, typhlitis, amebiasis
Ileocaecal TB imaging
most common GI TB, third most common extrapulmon TB
Barium
- flieschner (narrowing of the ileum, thickening of the valve)
- thickening and hypermotility of the caercum
- stierlin sign (empty caecum)
- chronic; fixed rigid valve, conical caecum, pulled caecum from fiorbosis)
CT
ileocaecal thickening
asymmetric valve thickening
mesenteric adenoaptyh with central low attenuation
ddx
- crohns (more ileal, less ascites, more vascularity)
- caecal carcinoma (eccentric, mets)
- small bowel lymphoma (thick, no stricture, lymphadenopathy/hepatosplenomegaly)
- amoebic colitis
Typhlitis is and imaging
necrotising inflammatory conditions originating in the caecum and extending out in immunocompromised
bowel wall thiickening
hypoechoic wall, echoic thick mucosa
fat stranding, pneumatosis
small bowel obstruction
Terminal ileitis ddx
IBD
Infectious
- cdiff
- salmonella
- yersinia
- tb
- typhlitis
Spondyloarthopathies
Ischaemia
Radiation
Vasculitidies
- SLE/PAN/HSP/Behcet and others
Neoplasic
- adenocarc, lymphoma, carcinoid
Drug related
Infiltrative
- EG
- sarcoid
- amyloid
- mastocytosis
Endometriosis
Coeliac disease is
a t cell mediated autoimmune gluten intolerance characterised by loss of villi in the proximal small bowel and malabsorption
Coeliac associations
Pulmonary haemosiderosis (Lane Hamilton)
IgA def
Cavitating mesenteric lymph node syndrome
Small bowel lymphoma
Down syndrome
CEC/Gobbi syndrome
IBD
Coeliac disease imaging
Fluoro
- Small bowel dilatation
- dilution of contrast
- multiple non obstructing intussusceptions (coiled spring)
- jejunoileal fold pattern reversal
- moulage sign
- mosaic pattern
- flocculation
- segmentation
CT
- jejunoileal fold pattern reversal
- small bowel dilatation/thickening
- stranding
- intussusceptions
- strictures
- vascular engorgement
- prominent nodes
- submucosal fat
- hyposplenism
Gallstone ileus is
an uncommon cause of mechanical bowel obstruction, occuring as a complication of chronic cholecystitis. stone fistula to small bowel and impaction at ileocaecal valve
Bouveret syndrome is
Gallstone ileus but causing gastric outlet obstruction
Gallstone ileus imaging
XR
- Rigler triad: obstruction, gas in biliary tree, gallstone
CT
- riglers again
- fistula site
- complications
Aortoenteric fistula is
pathologic communication between the aorta and GIT.
Can be primary (assoc with a complicated aneurysm) or secondary (assoc with graft repair)
Aortoenteric fistula imaging and ddx
Primary
Direct signs:
- ectopic gas in aorta
- presence of vascular contrast in GIT
Indirect signs:
- bowel thickening over aneurysm
- disruption of periarotic fat
- bowel/periaortic haematoma
Secondary
- increased perigraft soft tissue
- pseudoaneurysm formation
- disruption of aneurysmal wrap
- increased soft tissue between the graft and the wrap
ddx
- perigraft infection
- retroperitoneal fibrosis
- infected mycotic aortic aneurysm
- infectious aortitis
Duodenal adenocarcinoma is, risk factors and ddx
most common primary malignancy of the duodenum
risk factors;
- polyposis syndromes
- inflammatory disorders ie crohns, coeliac
- non hered polyps
ddx
- lymphoma
- NET
- pancreatic tumours
- periampullary tumours
- lower cbd tumours
- leiomyosarcoma
- benign polyp/adenoma/leimyoma/lipoma
Periampullary tumours are
those which arise within 2cm of the ampulla of vater
four main types
- pancreatic head/uncinate tumours
- lower common bile duct tumours
- ampullary tumours
- periampullary duodenal adenocarcinoma
Bulging duodenal papilla dddx
normal variant
patulous ampulla of vater
tumours
- IPMN
- ampullary
- periampullary
- cholang
- pancreatic
papillitis
autoimmune panc
choledochocele
impacted stone
GI neuroendocrine tumours classification
functional or non functional
TYPES
Insulinoma
- 50% of nets
- usually <2cm
- mostly pancreas
- 15% malig
Gastrinoma
- pancreas, LN, duodenum
- 20-30%
- variable size
- 75% malig
Non functioning
- pancrease
- 15%
- usually large and malignant
VIPoma
- pancreas, adrenal
- 3%
- 50% malignant
Glucagonomas and somatostatinomas
- rare
- pancreas
- malginant
Insulinomas are
most common pancreatic net, develop from ductal pluripotent cells into unregulated insulin secreting cells. equally distributed in pancreas
whipples triad
- hypoglycaemia
- sx of hypo
- immediate relief with glucagon
Assoc with MEN1
Insulinoma imaging
small
hypervascular
can have calcs
equal pancreas distribution
Gastrinomas are
second most common pancreatic endocrine tumour
associated with MEN1, and the most common type associated with it
associated with PUD - zollinger ellison syndrome
often malignant, extrapancreatic (duodenal)
occur in gastrinoma triangle
Gastrinoma/Passaro triangle boundaries
Confluence of cystic and common bile ducts
Junction of D2/D3
Junction of pancreatic head/neck
VIPoma is
a very rare pancreatic endocrine tumour that secrete vasoactive intestinal peptide.
WDHA syndrome; watery diarrhea, hypokalemia, achorhydria
location
- intrapancreatic, commonly tail
- extrapancreatic neurogenic; symp chain
- extrapancreatic non neurogenic; oesophagus, bowel, liver, kidney
Glucagonoma is
a pancreatic endocrine tumour that secretes glucagon. commonly malignant.
4d syndrome
- dermatitis
- diabetes
- DVT
- depression
typically large and metastatic at time of diagnosis. hypervascular.
Somatostatinomas are
a rare NET.
assoc;
- MEN1
- VHL
- NF1
Inhibitory syndrome
- DM
- cholelithiasis
- diarrhea
typically in the pancreas, but can also be duodenum/ampulla or vater
Whipples disease is
a rare infectious multisystem disorder caused by actinobacteria tropheryma whipplei
presents with migratory arthritis, weight loss, diarrhea, abdominal pain. can have hepatosplenomegaly and lymphadenopathy
Whipples disease features (by system)
GI
- jejunal micronodules
- thickened mucosal folds
- low density mesenteric nodes
CNS
- cortical or subcortical atrophgy
- hydrocephalus
- lesions; t2 hyper and mildly enhancing, no restriction
- midbrain, mesial temporal, hypothalamus and corticospinal tracts\
thoracic
- diffuse/focal infiltrates
- basal opacities
- nodules
- adhesions
- effusion
- nodes
Brunner gland hyperplasia is
disproportionate overgrowth of Brunner Glands in the duodenum from yperacidity. Multiple nodular filling defects, cobblestoning. ddx duodenitis.
Scleroderma GI manifestations
Oesophagus
- Dilated distally
- dysmotility
- reflux
Small bowel
- luminal dilatation
- reduced peristalsis
- hidebound bowel (crowding of valv c)
- accordion sign (evenly spaced mucosal folds)
- sacculation
Large bowel
- psedosacculation
- loss of haustra
- dilatation
- reduced transit
Intestinal angioedema imaging
Long segment concentric thickening
Mural stratification
Mild mesenteric oedema
Ascites
No nodes
Pancreatic trauma AAST grading
Proximal - right of SMV
Distal - left of SMV
Deep - to level of duct
Superficial - before duct
1: haematoma with minor contusion or superficial lac
2: major contusion or lac without ductal injury
3: distal transection or deep injury with duct injury
4: proximal transection or deep injury involving the ampulla or cbd
5: shattered head
Acute pancreatitis complications
Absent necrosis
- Acute peripancreatic fludi collection <4w
- Pseudocyst (encapsulated) >4 weeks
Necrosis
- acute necrotic collection <4w
- Walled off necrosis (encapsulated) >4w
Necrotic pancreatitis
- can lead to emphysematous pancreatitis
Vascular
- haemorrhage
- pseudoaneurysm
- splenic/portal vein thrombosis
Fistula into peritoneal cavity
Abdominal compartment syndrome
CTSI pancreatitis
Balthazar score A-E
A normal 0
B enlargement 1
C inflammatory 2
D single collection 3
E two or more collections 4
Necrosis
none 0
<30% 2
30-50% 4
>50% 6
Score /10
Sentinel loop is
a short segment of adynamic ileus close to an inflammatory process on xr. upper abdomen - pancreatitis. right lower quadrant - appendicitis.
Colon cut off sign is
distension proximal colon, abrupt termination at splenic flexure, decompression distally
LUQ pathologies;
- pancreatitis (phrenicocolic lig via tv mesocolon)
- carcinoma
- IBD
- mesenteric ischaemia
- abdominal aortic aneurysm rupture
- stomach tumorus
Autoimmune pancreatitis associations
Igg4 sclerosing disease
RA
Sjogrens
IBD
Autoimmune pancreatitis imaging
Sausage shape
Minimal stranding, confined to peripancreatic
Peripancreatic low rim/halo
MR
T1 low
T2 minimally incre
C+ delayed
DWI restricts
MRCP ?strictures
Other sites
- nodes
- renal inflamm pseudotumours
- retroperitoneal fibrosis
- pleural effusions
- CBD strictures
-mediastinal nodes
Autoimmune pancreatitis ddx
Diffuse
- lymphoma
- plasmacytoma
- mets
- infiltrative ductal adeno
Focal
- ductal adenocarcinoma
Tropical pancreatitis
SPINK1 mutation
Tropical countries
Younger
Large ductal calculi
Emphysematous pancreatitis is
complications of acute caused by secondary necrotising infection. gas forming bacteria.
Hirschsprung imaging
XR
Bowel obstruction. Affected bowel is smaller in calibre
Fluoro
Affected segment small calibre with proximal dilatation
Saw tooth irregularity of the segment
Reversed rectosigmoid ratio
Meconium plug syndrome is
functional colonic obstruction in a newborn due to an obstructing meconium plug. Usually tyransient and affects the left colon (small left colon syndrome)
Meconium plug syndrome imaging
XR
multiple dilated loops
Fluoro
small calibre left colon with filling defects due to retained meconium
rectum is normal in size
Necrotising enterocolitis imaging
XR
dilated bowel loops
loss of the normal gas shapes
thumbprinting
pneumatosis
portal venous gas
pneumoperitoneum
Ogilvie syndrome is
colonic pseudo obstruction. acute distension without an underlying mechanical obstruction
Ulcerative colitis associations
PSC
Moya moya
Ank spon
CRC
Coeliacs
Lung disease
Uveitis and iritis
Erytheme nodosum and pyoderma gangrenosum
Thrombotic comps
fatty liver
Seronegative spondyloarthropathies
Chronic hepatitis
Ulcerative colitis imaging
XR
Thumbprinting
toxic megacolon
Fluoro
Granular mucosa
Lead piping
CRC
CT
Lead piping
Wall thickening
Mural stratification
Submucosal fat deposition
Thickening perirectal fat
CRC
Pneumatosis
MR
Wall thickening
Diffusion restriction
Enhancement of the mucosa
Loss of haustra
Toxic megacolon is and causes
Acute complication in IBD. Fulminant colitis cuases neurogenic loss tone of the colon leading to severe dilation and perforation
Causes
UC
Crohn
Infectious, particularly cdiff
Neutropaenic colitis
Ischamia
Radiation
Lymphoma
GVHD
Hypothyroidism
Hrischsprungs
Infectious colitis imaging
Wall thickening with homogenous enhancement
Ascites
Stranding
Right colon; yersinia, salmonella
Diffuse; CMV, e coli
Left; shigella, schistosomiasis
Rectosigmoid; gonorrhea, herpes, trchomatis
CRC staging
T0 no evidence
Tis in situ
T1 into submucosa
T2 into muscularis
T3 into subserosa or into non peritonealised tissues
T4a visceral peritoneal layer
T4b adjacent organs
N0 none
N1a 1 regional
N1b 2-3 regional
N1c serosa/non peritoneal tissue without regional
N2a 4-6
N2b >7
M0 no
M1a one organ without peritoneal
M1b multiple organs no peritoneal
M1c peritoneum with or without others
Mucinous neoplasms of the appendix include
Premalignant
- adenoma
- serrated polyp
Uncertain
- low grade appendiceal mucinouss neoplasm
- high grade appendiceal mucinous neoplasm
Malignant
- appendiceal mucinous adenocarcinoma
- poorly diff mucinous with signet ring cells
- mucinous signet ring cell carcinoma
Pseudomyxoma peritonei is
a syndrome of progressive accumulation of mucinous ascites related to a mucin producing neoplasm, usually appendix.
Pseudomyxoma peritonei imaging
Loculated collections of fluid accumulating along the peritoneal surfaces rsulting in scalloped appearance of teh coated organs and omental caking
Omental caking ddx
TB
Lymphoma
Malignant peritoneal mesothelioma
usually from ovaries, gastric or colon
Appendiceal mucocoele is and causes
abnormal accumulation of mucin causing distention of the vermiform appendix
Causes
- mucus retention cyst
- mucosal hyperplasia
- mucinous cystadenoma of the appendix
- mucinous adenocarcinoma of the appendix
Appendiceal mucocoele imaging
XR
peripheral calcs
US
onion sign (layering)
can have some shadowing
CT
low attenuation
at caecum
mural calcs
nodular - cancer
gas - infection
MR
T1 variable
T2 yperintense
Low grade appendiceal mucinous neoplasms (prev cystadenomas) are
rare mucinous tumours of the appendix showing low cytoligc atypia. Distinguished from HAMN on histo grounds.
Suspcious features of HAMN
- soft tissue thickening
- wall irregularity
- PMP
Perianal fistula classification
Intersphinteric - does not cross external
Transpincteric - from intersphincteric space through external into ischiorectal fossa
Suprasphincteric - superiorly into intersphincteric space, over puborectalis and through iliococcygeus into ischiorectal fossa
Extrasphincteric - perineal skin through ischiorectal fossa and levator ani muscle complex into rectum
Splenic haemangiomas are
second most common splenic lesion after cyst. slow flow venous malformation. similar imaging to hepatic haemangioma.
Splenic lymphangioma is and imaging
rare benign tumours corresponding to abnormal dilation of lymphatic channels. can be congenital or acquired. present as lobulated or multiloculated cystic lesions. can have curvilinear mural calcifications
Splenic hamartoma imagig
variable US
CT
heterogenous enhancemnt
iso or hypodense
MR
T1 iso
T2 heterogenously hjyper
C+ vivid immediately post con (unlike haemangioma), delayed uniform with central hypovascular
SANT imaging
US
hypoechoic
CT
homgenous, hypodense or isodense
enhancing rim and radiating enhancing tissue (spoke wheel)
MR
T1 heterogenous low to intermediate
T2 low
C+ peripheral and septal enhancement spoke wheel. non enhancing stellate scar.
Hepatic/splenic TB imaging
hepatosplenomebgaly
US
miliary nodules or larger masses
CT
miltple low attenuaiting
eventually calcify
can have large lesion with target sign
DDX
Micronodular
- lymphoma
- fungal
- mets
- sarcoid
Macro
- abscess
- mets
- primary
Splenic siderosis is and imaging
gamna gandy bodies
microhaemorrhage with haemosidering dep
usually seen in PH but also haematolgoical conditions
US
multiple echoic with shadowing
CT
look like granuloms
MR
siderotic foci punctate througout
Wandering spleen is
migration of the spleen
abnormality of its suspendosry ligaments
can infarct
aetiology
- sickle cell
- heterotaxy
- trauma
- mono
Pancreatic ductal adenocarcinoma risk factors
Cigs
Chronic pancr
Diet
Obesity/DM
Family hx
Hereditary syndromes
- BRCA2
- HNPCC
- FAMMM
- peutz jehger
Pancreatic ductal adenocarcinoma imaging
Fluoro
- inverted three sign
- wide sweep
US
- double duct
- mass
CT
- poorly defined
- surrounding desmo reaction
- enhance poorly
- double duct
MR
T1 hypo
T1FS hypo
C+ delayed
T2 variable
MRCP DD
Pancreatic ductal adenocarcinoma staging
T1 <2cm
T2 2-4cm
T3 >4cm
T4 encasing SMA/Coeliac aa
N0 none
N1 1-3 regional
N2 4 or more regional
M0
M1
Serous cystadenoma of the pancreas pathology
polycystic
honeycomb
macrocystic (<10%)
Associated with VHL
Serous cystadenoma of the pancreas imaging
Location
- distributed throughout
CT
multicystic
lobulated
bunch of grapes
>6 cysts
<2cm in size
enhancing central scar
stellate central calcification
MR
T1 low
T2 low fibrous scar, high signal cysts
C+ fibrous septa enhance
No communication with duct
Serous cystadenoma of the pancreas ddx
IPMN - communicates
Pseudocyst
Mucinous - peripheral calcs, bigger cysts, usually unilocular
SPPN
Mucinous cystadenoma of the pancreas imaging
Mostly body/tail, can be head
CT
- rounded contour
- peripheral calcs
- heterogenous attenuation
- internal septa
- can be uni or multilocular
Mucinous cystadenocarcinoma of the pancreas imaging
Numerous large cysts
Smooth contour
Thicker walls
Amorphous calcs, septations, solid excrescences can be seen
No central scar
MR
Mucin high T1
Cysts high T2
Calcs low
Pancreatic duct conventional arrangement
Main duct
- Dorsal duct proximal to dorsal ventral fusion
- drains at the ampulla of vater
- connects with the accessory pancreatic duct
Duct of Wirsung
- distal main duct
- segment of ventral duct between fusion and major papilla
- continuous with the main duct proximally
Accessory duct of Santorini
- Portion of dorsal duct distal to dorsal ventral fusion
- Drains anterior superior head
- Can drain to minor papilla
- Can persist as a branch of the main duct
Pancreas divisum is
Failure of dorsal/ventral fusion
Dorsal duct drains most of pancreas via the minor papilla
Can result in a santorinicoele
Types
- Classic; no connection
- Absent; no Wirsung, major papilla only drains CBD
- Functional; filamentous connection
Meandering main pancreatic duct is
Main pancreatic duct that drains into major papilla after performing a reverse Z type or Loop turn in the pancreatic head
Ansa pancreatica is
Communication between the duct of wirsung and duct of santorini
Arises as a brnach duct from the main, descends down, loops upward and terminates at the minor papilla
Anomalous pancreaticobiliary junction is
abnormal junction of the pancreatic duct and CBD outside the duodenum to form a long common channel >15mm
Can have associated biliary dilatation, or
- choledochal cyst
- stricture
- pancreatic anomalies
- synchronous biliary cancer
Annular pancreas is
a morphological anomaly that results in pancreatic tissue completely or incompletely encircling the duodenum. can cause duodenal obstruction.
develops due to failure of the ventral bud to rotate with the duodenum causing encasement
Non neoplastic pancreatic cysts:
Unilocular
- pseudocyst
- simple cyst
Diffuse
- VHL
- CF
- ADPKD
Macro multi
- hydatid
Cystic/solid
- WON
IPMNs are
epithelial pancreatic cystic tumours of mucin producing cells that arise from pancreatic ducts
IPMN types
Main
- segemental or diffuse
- higher malig potential
- look like chronic pancr
Branch
- head and uncinate
- localised and mass like
- can be multifocal
- macro or microcystic
- typically indolent
Mixed
IPMN imaging
Communicate with a duct
CT
single or multiple cystic lesions
dilatation of the main duct
do not calcify
MR
Main
- Main duct >5mm
- segment or diffuse dilation
- mucin signal
- thin parenchyma
- solid mural nodules concerning
- mucin dependantly in the duct
Branch
- single or multiple side branches with dilation
- cystic mass like appearance
- bunch of grapes
IPMN worrisome features
Main
- duct 5-9mm worrisome
- >10mm high risk
- enhancing components
Branch
- main duct >5mm
- cyst >3cm
- >5mm enhancing nodule
- solid mass
- thickened/enhancing cyst wall
- growth rate >5mm/year
Nodes
Abrupt change in calibre with distal atrophy
Elevated CA19 9
Solid pseudopapillary tumour of the pancreas is
a rare and usually benign pancreatic cystic neoplasm most commonly seen in young females
Solid pseudopapillary tumour of the pancreas imaging
Pancreatic tail
CT
encapsulated lesion
solid/cystic
cystic usually more central
Calcifications and enhancing solid components
MR
T1 low
T2 heterogeneous to high
C_ heterogenous and slowly progressive
Acinar cell carcinoma of the pancreas imaging
CT
enhancing oval solid
often NO biliary duct dilatation
can have calcifications
can invade adjacent organs
Pancreatoblastomas are
rare paediatric tumours of the pancreas. around 4yo. assoc with beckwith wiedemann syndrome
Pancreatoblastoma imaging
CT
well defined
heterogenous
solid/multilocular cystic components
enhancing septa
fine calcifications
MR
T1 low
T2 hetero high
Anal cancer imaging and staging
MR
T1 low to muscle
T2 high to muscle
T1 <2cm
T2 2-5cm
T3 >5cm
T4 invasion of adjacent organ
N1a inguina, mesorectal, internal iliac
N1b external iliac
N1c N1a + N1b
M0 M1
Hepatitis imaging
US
hepatosplenomegaly
starry sky
GB thickening
periportal oedema
decreased echotexture
CT
hepatomegaly
periportal oedema
decreased attenuation on NC
lymphadenopathy
MR
T1 periportal oedema
C+ delayed periportal enhancement
IP/OP steatosis
Mirizzi syndrome is
extrinsic compression of the extrahepatic biliary duct from calculi in the cystic duct or gallbladder. may have an associated cholecystodochal or cholecystoenteric fistula
Acute calculous cholecystitis complications
gangrenous
perforation
emphysematous
abscess
fistula
vascular
Acalculous cholecystitis is
cholecystitis without stones or where stones arent contributory. typically critically unwell patients or injured patients.
Chronic cholecystitis imaging
NM/HIDA
delayed visualisation bw 1-4 hours
?EF after cholecystokinin
Emphysematous cholecystitis is
a rare form of cholecystis with wall necrosis causing gas formation in the lumen/wall. surgical emergency. usually older and diabetic patients
Emphysematous cholecystitis imaging
US
Ring down
Champagne sign
CT
Gas
Xanthogranulomatous cholecystitis is
an uncommon inflammatory cause, characterised by multiple intramural nodules. rupture of rokitansky aschoff sunses
Xanthogranulomatous cholecystitis imaging
US
thickening
intramural hypoechoic nodules or bands
stones
infiltration of liver
CT
small intramural hypoattenuating nodules
poor enhancement
local infiltration
Primary sclerosing cholangitis is
an uncommon inflammatory condition affecting the biliary tree resulting in multiple strictures and cirrhosis
unlike PBC, ab titers are low
PSC associations
IBD, especially UC
Autoimmune hepatitis
Sjogrens
Retroperitoneal fibrosis
Mediastinal fibrosis
Riedels thyroiditis
Orbital pseudotumour
PSC imaging
General:
multiple strictures entire tree
cirrhosis, with left lobe atrophy
caudate hypertrophy
US
cirrhosis
irregular ducts
bright portal triads
?GB ca
CT
atrophy involving left
caudate hypertrophy
bile duct dilatations/strictures
MRCP/ERCP
multiple short segment structures
beading intervening
biliary diverticula
mural irregs
PSC complications
hepatic osteodystrophy
cholangiocarcinoma
CRC
HCC
GB ca
PSC ddx
Cirrhosis
- left lobe usually hypertrophied
- caudate not as large
IgG4 related SC
- older
- more systems
- elevated igg4
Secondary sclerosing
- aids
- other strictures
Cholangiocarcinoma
PBC
- younger women
- high ab titres
Alagille syndrome
Hepatic sarcoid
Secondary sclerosing cholangitis causes
Chronic obstruction/recurrent cholangitis
Ischaemic cholangiopathy
Infectious, especially aids
Acute ascending cholangitis causes and imaging
E coli
typically obstructive
- choledocholithiasis
- malig
- sclerosing cholangitis
- biliary procedures
Imaging
- duct dilation
- bile duct wall thickenning
- stones
Recurrent pyogenic/oriental cholangiohepatitis is
commonly found in SE asia patients characterised by bile duct strictures and dilatation with intraductal pigmented stone formation
Recurrent pyogenic/oriental cholangiohepatitis imaging
dilatation and multilevel strictures
intraductal pigmented calculi
regions of segmental atrophy
CT
hyperdense stones
focal fibrosis, heterogenous enhancement and focal steatosis
MR
reduced arborisation of peripheral ducts (arrowhead)
multiple strictures
IgG4 related sclerosing cholangitis is
also known as autoimmune and is part of the igG4 spectrum. can also occur in isolation
Cirrhosis is and aetiology
common endpoint of chronic liver diseases which cause hepatocellular necrosis
Causes:
- alcohol
- viral
- NASH
- biliary disease (PBC, PSC)
- metabolic (haemochromatosis, wilsons, alpha 1)
- autoimmune
- vascular (congenstive, budd chiari)
- CF
Cirrhosis imaging
General
- caudate/left lobe hypertrophy
US
- surface nodules
- coarse/heterogenous
- segmental hypertrophy/atrophy
- enlarged PV
- slow/reversed PV flow
- cavernous malformation
- recanalisation
- collaterals
- portal hepatic vein waveform
- splenomegaly
- ascites
- fatty change
CT
- surface and parenchymal nodularity
- fatty change
- parecnhymal heterogeneity
- PV supply to dysplastic nodules
- lobar hypertrophy/atrophy
- signs of portal hypertension
MR
Regen nodules
- T1 iso or hyper
- T2 iso
- no early enhancement/washout
Siderotic
- T2 hypo
Dysplastic
- can look like regen of hcc
HCC
- arterial enhancement and washout
- late enhancing capsule
- T2 hyper
Cirrhosis ddx
Pseudocirrhosis
Miliary liver mets
Budd chiari
Hepatic failure
Sarcoid
PBC
Chronic portal vein thrombosis
Nodular regnerative hyperplasia
Cirrhosis CNS manifestations
hepatic encephalopathy
alcohol
- osmotic demyelination
- wernickes
- marchaifava bignami
Wilsons (siderosis)
Haemochromatosis (hypopituitarism and parkinsons)
Cirrhosis MSK manifestations
varices
haematomas
infective complications
osteodystrophy
avn
sarcopenia
Cirrhosis pulmonary manifestations
Hepatopulm syndrome
- dilation of pulm vasculature
Portopulmonary hypertension (PAH)
hepatic hydrothorax
ARDS
Primary biliary cholangitis is
chronic progressive cholestatic liver disease. destruction of small intrahepatic bile ducts, portal inflammation and progressive scarring. AMA high. causes cirrhosis
PBC associations
cholelithisis
autoimmune diseases
interstitial lung disease
pulmonary hypertension
hcc
PBC imaging
MR
T2
- parenchymal lace like fibrosis and periportal halo sign
periportal halo sign; low signal intensity around portal venous branches
Other
- periportal hyperintensity
- segmental hypertrophy of the caudate
- hepatic surface irregularity
Portal vein thrombosis causes
Reduced flow
- cirrhosis
- malignancy
Hypercoagulability
- inherited conditions
- malignancy
- myeloproliferative disorders
- IBD
- dehydration
- OCP
- pregnancy
- trauma
Endothelial disturbance
- local inflammation
Portal vein thrombosis imaging
US
- filling defect
- internal flow in tumour thrombus
CT
- dilling defect
- enhancement of the wall (dilated vasa vasorum)
- THAD
- enhancement; tumour
- cavernous transformation in chronic
- bowel ischaemia acute
- portal hypertension
MR
T1
- acute high signal
T2
- acute high signal
- chronic low signal
C+
- may enhance post con in tumour
- THID
Cavernous transformation of the portal vein is
sequla of portal vein thrombus. replcement of PV with numerous tortuous venous channels
Cavernous transformation of the portal vein imaging
General
- dilated vessels
- left atrophy
- hypertrophy segment 4 and caudate
US
- numerous vessels occupying the portal vein bed
CT
- numerous vascular structures
- calcs in the thrombus
AAST liver injury scale
Grade 1
- subcap haematoma <10%
- laceration <1cm
Grade 2
- subcap haematoma 10-50%
- intra haematoma <10cm
- laceration 1-3cm
Grade 3
- subcap haematoma >50%
- intra haematoma >10cm
- laceration >3cm
- vascular injury contained to parenchyma
Grade 4
- laceration 25-75% lobe or 1-3 segments
- vascular injury into peritoneum
Grade 5
- laceration >75%
- vascular; juxtahepatic venous injurie
Multiple hepatic cysts associations
VHL
ADPCKD
Hepatic cyst ddx
hydatid
abscess
biloma
biliary cystadenoma
choledochal cyst
mets
biliary hamartoma
Peribiliary cysts are
seen in chronic liver disease. cystic formation around the biliary ducts, typically hilar. dont communicate with the biliary tree.
Hepatic haemangiomas are
benign vascular liver lesions. congenital, non neoplastic and typically cavernous subtype.
Hepatic haemangioma associations
extra hepatic haemangiomata
hereditary haemorrhagic telangiectasisa
kasabach merritt syndrome
hepatic arterioportal shunt
Hepatic haemangioma imaging
US
- well defined
- hyperechoic
- peripheral feeders
CT
- discontinous nodular peripheral enhancement
- progressive centripedal fill in
- bright dot sign
MR
T1 hypo
T2 hyper
Gad peripheral nodular discontinuous. retain on delayed
Prim variable on delayed
DWI high, with high or mixed ADC
Giant hepatic haemangioma imaging
CT
heterogenous, central low attenuation
typical enhancement but less consistent
may never totally fill in
MR
T1
- hypo
- clefts of low
T2
- clefts high
C+
- hypo clefts
- otherwise similar
Hyalinised/sclerosing hepatic haemangiomas are
variants of haemangiomas which contain extensive fibrous tissue and thrombosed vascular channels giving an unusual imaging appearance that cant be differentiated from malignancy
Hyalinised/sclerosing hepatic haemangioma imaging
MR
T1
- hypo
T2
- variable, typically lower than a regular
C+
- absent or mild arterial
- slight peripheral late
- usually a thin peripheral rim
Can have some retraction and THID
Flash filling hepatic haemangiomas are
atypical haemangiomas, benign, with imaging features that can be suspcious for malignancy
Flash filling hepatic haemangioma imaging
Small
US
hyper
CT
intense homogenous arterial enhancement
isodense on delayed
can have phleboliths
MR
T1 hypo
T2 hyper
C+ enhancement no washout
ddx
- hcc
- hypervascular met
- fnh
Focal nodular hyperplasia is
a regenerative mass of the liver, second most common benign liver lesion. thought due to hyperplastic growth of normal hepatocytes with malformed biliary drainage