Gastroenterology Flashcards
two types of hiatus hernia?
Sliding
Rolling
Most common type of hiatus hernia
sliding
what ligament normally attached the oesophagus to the hiatus?
phrenico-oesophageal ligament
Define a rolling hiatus hernia
The stomach herniates above but the GOJ remains in the same position
what happens to GOJ during REM sleep?
Lower oesophageal sphincter relaxation - can cause reflex which is normal
The length of the LOS and the pressure required to maintain competence are related. The ??????? the sphincter, the lower the pressure needed to maintain competence.
longer
what happens to the length of the LOS after overeating?
It shortens, therefore higher pressures are required to keep it working.
reflux is normal if overeating in people
How much GORD is not detected at endoscopy?
40%
symptomatic but without oesophagitis
what does a fatty diet cause in the stomach motility?
delayed gastric emptying
Overeating and delayed gastric emptying (fat in diet) cause:
Prolonged fundal distension
Sphincter shortening
Repetitive transient LOS pressure collapse
How bad is GORD to be seen on barium?
Very bad
less than 2cm
less than 1cm intrabdominally
What are the three groups of patients who get GORD and develop symptoms/side effects?
One group of patients develop gastric metaplasia (Barrett’s) and become at increased risk of adenocarcinoma formation.
Another group develop visible oesophagitis which may progress to ulceration and stricture formation.
A third group appear to have little visible response (endoscopic negative GORD) but can be quite symptomatic.
features of reflux oesophagitis - motility issues
Abnormal motility (up to 50%): impaired primary peristalsis, proximal escape of barium (i.e. barium left behind during the peristaltic wave indicative of reduced amplitude), tertiary contractions
features of reflux oesophagitis
nodularity
ulceration
IN barium studies what is the difference between an A ring and a B ring?
An A ring is due to muscular contraction of the oesophagus at the junction of the tubular oesophagus and the vestibule. By its nature, an A ring is transient and not a fixed stricture.
B ring -An A ring is due to muscular contraction of the oesophagus at the junction of the tubular oesophagus and the vestibule. By its nature, an A ring is transient and not a fixed stricture.
What cancer devlops in Barretts oesophagus
adenocarcinoma
What are the symtpoms of post parandial choking attacks
choking
asthma - try PPI if high gord suspicion, otherwise 24 hr pH moniotr.
cough
chronic laryngitis
Raised upper oesophageal pressure on barium study might show?
Premature closure or non relaxing cricopharyngeus
Zenkers pouch formation
Raised upper oesophageal pressure findings on endoscopy
laryingyitis
airway (upper) inflammation
reporting on a patient with suspected reflux disease:
headings
Indication
Technique
Findings:
Structure
Motility assessment
Reflux assessment
Marshmallow test
Conclusion:
No evidence of GORD
Early GORD
Advanced GORD
Recommendations:
Endoscopy
Consideration of surgical opinion
The mucosal pattern is the ‘feline’ oesophagus or the ‘oesophageal shiver’. what does this indicate?
contraction of muscularis mucosae response to acid reflux
GOJ star pattern view is associated with what?
The star pattern with a mound suggests a tightly closed sphincter which is bulging into the fundus. This indicates a competent sphincter and whilst intermittent reflux due to transient relaxations may occur, volume reflux is less likely.
Oesophageal intramural pseudodiverticulosis can lead to what complication
Squamous carcinoma
What are the most common oesophageal tumours>
adenocarcinoma and SCC
1-year-survival for metastatic oesophageal cancer
20%
UPPER GI imaging is mostly for what purpose?
staging and response to treatment.
Endoscopy and biopsy are done for the symptoms
what are the oesophagus landmarks for the three parts
oharynx to aortic arch
aortic arch to inferior pulmonary vein
inferior pulmonary vein to GOJ
risk factors for oesophgeal SCC
smoking and alcohol
age - over 40
afrocaribbean
radiotherapy
hot drinks
Oesophageal SCC is associated with what other cancers?
Head and neck SCC - staging often includes the neck
Oesophageal SCC is most common in which part of the oesophagus?
middle - 50%
What is Barretts
rrett’s oesophagus: This is a condition where oesophageal stratified squamous cell epithelium undergoes metaplasia to columnar epithelium.
Patients with high grade dysplasia are given what options?
Surgey - oesophagectomy - are considered - 30% will develop cancer.
Once oesophageal tumour is confirmed, further investigations can be considered to aid staging:
Positron emission tomography (PET)/CT
Endoscopic ultrasound
Oesophageal CT tumours
Oesophageal tumours usually show as thickening of the oesophageal wall. The oesophagus proximal to the tumour may be dilated and contain food residue.
what is diagnostic for achalasia? physiology teting
high pressure scphincter that doesn’t relax.
biochemical indicators of iron deficiency anaemia
Low ferritin <12-15 μg/l
Microcytosis
Hypochromia
B12 and/or folate deficiency may mask hypochromia and microcytosis: look for increased red cell distribution width (RDW)
The serum ferritin correlates well with iron stores, but it can also be elevated with…. ?
liver disease, inflammatory conditions, and malignant neoplasms.
Common causes of occult GI blood loss
Aspirin NSAID 10-15%
Colonic carcinoma 5-10%
Gastric carcinoma 5%
Benign gastric ulceration 5%
Angiodysplasia 5%
Risk factors of colon cancer
Genetic - FAP
IBD - UC and diet
How is colon cancer staged?
TNM
Colon cancer - 80%of all colon cancers are what stage at presentation?
T3 - Tumour extends beyond the muscle layer into pericolic or perirectal tissue
Fro colon staging scan what parameters should be used?
Oral contrast. IV contrast with delay of 25s thorax and 60 s for abdo pelvis
Colon cancer when can MRI be used?
distal sigmoid and upper rectum
Colon cancer when can PET CT be used?
recurrence if markers going back up. Detectin of extrahepatic disease if undergoing hepatic recetion for metastasis
Colorectal TNM - what is the N staging
N0 - none
N1 three or less
N2 - four or mroe
streaky change in the fat surrounding the sigmoid colon, which may be a result of ???
peritumoural inflammation or infiltration of tumour into the surrounding fat.
Colorectal cancer staging - lymph node size cut offs?
if >1cm likely malignanct involvement.
If under then likely inflammatory.
Colon cancer relationship of lung and liver mets?
If lung mets then normally there will be liver mets first
Colorectal cancerr - why do MRI?
Determining the size, location and extent of primary tumour
Evaluating the relationship to adjacent structures, particularly the mesorectal envelope, the prostate/seminal vesicles or uterus/vagina
Establishing the presence and extent of LN involvement
Low rectal tumours an achieve wider dissemination - why?
bypoass the liver capillary netowrk that captures other cells
or lymphatic spread
Colorectal cancer - R2 meaning
there is macroscopic involvement of tumour resection margin.
Colorectal cancer - R1 meaning
indicates that there is microscopic involvement of the resection margin or that the tumour comes within 1 mm of the margin.
Colorectal cancer - R0 meaning
R0 indicates that there was a margin of at least 1 mm of normal tissue between the tumour and the resection margin.
Path report - V1
Vascular invasion.
Vascular invasion of colon cancer seen on what modality?
MRI - if greater than 3mm
Patients with lymph node involvement at surgery are usually offered are usually offered what?
adjuvant chemotherapy to reduce the risk of recurrent disease.
Colon cancer - metastatic locations
27% of patients develop liver metastases, approximately two thirds are identified at presentation and the other third present in next 3 years.
Colon liver mets appear as what on CT? and why?
hypovascular and so best seen as hypodense on portal venous phase study.
Colon liver mets appear as what on MRI? and why?
MR metastases are typically intermediate low signal on T1 and intermediate high signal on T2, and are hypovascular with the thin rim of peripheral enhancement seen almost invariably on an arterial phase acquisition post-gadolinium
Do mets take up MR contrast?
no
Colon cancer - Right-sided tumours recur within …..
para-aortic nodes adjacent to the superior mesenteric artery (SMA),
Colon cnacer - left-sided tumours metastasis
to the para-aortic nodes adjacent to the origin of the inferior mesenteric artery (IMA).
why are liver and lung mets excised?
cascade of colon mets shows that once embedded in liver and lung it then goes all throughout the body. Attmepts to stop the cascade at the liver and lung have been successful in patiens.
How is MRI used to differnetiate recurrence at an anastomosis?
Magnetic resonance imaging is better at differentiating between malignant and benign disease. Fibrosis is usually dense dark material on T2 with angular margins whereas tumour is of intermediate signal with rounded margins and rim enhancement
Hydronephrosis post colon cancer surgery?
Sinister sign for recurrence
IN colon cancer when is MR used?
if there is a known liver met and no extra hepatic mets then can be used to aid surgical approach
Chemo in the use of cancer treatment - 3 types what are they>
As a treatment therapy in its own right, as in this situation where there is identifiable recurrent disease
As an adjuvant therapy when the primary therapy has been completed (usually surgery) with no residual macroscopic disease but the histological features of the tumour put the patient at high risk of recurrence (e.g. a T3 N1 V1 colonic tumour), chemotherapy being used to reduce the risk of recurrence
As a neoadjuvant therapy where chemotherapy is used (often in combination with radiotherapy) prior to what is considered the definitive treatment (surgery) to improve the likelihood of a favourable outcome e.g. converting a rectal cancer which is deemed as likely to have a R1 resection on the basis of a staging MR to an R0 resection after chemoradiotherapy and thus reducing the risk of local and distant recurrence
what are diverticula?
herniations of mucosa and submucosa through the colonic wall.
which points are suscepitble to divertiucla?
Where the vasa recta penetrate
two types of diverticlosis
The first one is mainly left-sided, discernible by muscle thickening (acquired, low-residue diet and physical inactivity implicated, prevalence rises with age)
The other is due to diffuse connective tissue abnormality, resulting in pancolonic disease
Diverticulitis CT features
Diverticula
Fat stranding
Centipede sign (hyperaemic engorged vasa recta)
Arrow head sign
Wall thickening >4 mm
How to diverticula bleeds occur?
They occur through arterial blood supply - thinnning of the vasa recta
External anal sphincter is made of what muscle?
Striated muscle
Squeezed to withold defecation
internal anal sphincter is made of what@
smooth muscle
85% of resting anal pressure
What muscle lies between the EAS and IAS ?
interspincteric plane - longitudinal muscle
On US - smooth muscle is generally what kind of pattern?>
hyporeflective
what are the two causes of incontinence>
- Disruption of the sphincter muscles
childbirth but can also occur secondary to surgical procedures, trauma, etc.
- Atrophy of the sphincter muscles
This may be due to ageing or the effect of pudendal nerve stretching during pregnancy and childbirth.
what are the two syndromes of anal spinchter atrophy?
IAS atrophy or ‘degeneration’ where the IAS is thinned and difficult to visualise
EAS atrophy where the EAS is thinned and replaced by fat
Fistula in ano is believed to arise from ??????
chronic infection of the anal glands.
‘Parks classification of sphincters is what?
Intersphincteric
Transsphincteric
Suprasphincteric
Extrasphincteric
How to treat fistulas in anus?
lay - open
can be tricky based on type of fistula and not causing further damage.
Imaging therefore is to evaluate surgical approach and also review for extensions
Anal fistula
A certain fistula cannot be an intersphincteric fistula because these never have tracks in the ischioanal fossa, but it could be one of the following:
Transsphincteric
Supralevator
Extrasphincteric
Supralevator sepsis in anal fistulas is important to note - why?
difficult to treat surgically and is very important to detect pre- or peri-operatively.
infection above the pelvic floor - best seen on coronal views on MR
T or F
MR imaging is as accurate as clinical examination for classification of fistula in ano
F
MR imaging is far superior.
T or F
The main role of MR imaging is the pre-operative detection of areas of sepsis
T
It has been shown that MR imaging can detect sepsis that would otherwise be missed.
T or F
Sphincter division is greater for a transsphincteric fistula than intersphincteric fistula
T
When laying open an intersphincteric fistula the EAS is not divided.
T or F
The internal opening of a suprasphincteric fistula is higher than an extrasphincteric fistula
F
The internal opening of extrasphincteric fistulas are, by definition, above the anal canal whereas suprasphincteric fistulas open into the anus, usually at the dentate line.
T or F
It has been shown that pre-operative MR imaging can reduce subsequent fistula disease
T
By up to 75% in complex cases.
Liver is created in which mesentry?
ventral
falciform ligament become what?
ligamentem teres
Special blood supply of caudate lobe?
frm left and right hepatic arteries.
Venous drainage straight to IVC
Oesophageal staging type
TNM
Oesophagus lymph node drainage?
nodes near the primary are involved and from there, drainage may take place superiorly through the para-oesophageal lymphatics to the paratracheal, mediastinal, hilar, para-aortic, cervical and internal jugular nodes. Inferior drainage takes place through the para-oesophageal nodes to para-cardial, left gastric and beyond to celiac axis, and abdominal para-aortic nodes.
Location of Oesophageal mets?
liver and lung being the most common sites. Other sites include brain, bone, and intra-abdominal organs.
When is PET /CT FDG used in oesophageal cancer?
Proximal to GOJ
if no mets found on CT then PET is done with diangostic laparoscopy and endoscopic ulrasoun
normal oesophageal wall thickness
is less than 3 mm thick
How to tell T staging?
Very difficult
if outer edge against fat is irregular assume T3.
Oesophageal cancer lymph node size cut off?
10mm
though some groups are 6mm like supraclavicular
Features of a benign node
Benign nodes tend to be oval, triangular, flat or kidney shaped
features of malignant node
fatty core replaced by malignant tissue, spherical, hypoechoic, well defined
Oesphageal T staging
T1 Tumour invades lamina propria, muscularis mucosae, or submucosa EUS
T1a Tumour invades lamina propria or muscularis mucosae
T1b Tumour invades submucosa
T2 Tumour invades muscularis propria EUS
T3 Tumour invades adventitia EUS, CT
T4 Tumour invades adjacent structures EUS, CT
T4a Resectable tumour invading pleura, pericardium, or diaphragm Positron emission tomography (PET), CT/EUS
T4b Unresectable tumour invading other adjacent structures, such as the aorta, vertebral body, and trachea PET, CT/
Fluorouracil (5 FU)) can produce what side effect
coronary spasm
reasons for neo adjuvant therapy
sterilise lymph nodes
down stage the disease
reduce chance of spread
post chemo CT reviews what?
Size of primary
size of lymphadenopathy
any mets / response
Gastric cancer risk factors
low fruit and veg
smoked food, salted foods
Gastric cancer signs and symptoms
Indigestion
nausea and vomitting
dysphagia
postprandial fullness
Gastric cancer late complicaitons
pathologic perotneal and pleural effusions
GOT obstruction
bleeding
Duodenal cancer - risk facotrs
coeliac disease
crohns
colonic polyps
Duodenal cancers are mostly
Adenocarcinomas
others are carcinoid and sarcomas
how does H Pylori cause gastric cancer
Atrophic gastritis leads to atrophy, metaplasia, dysplasia and then malignancy.
Pernicious anaemia gives a higher risk of what
gastric malignancy
Relationship of mgastric polyps to gastric malignancy
gastric polyps are less common than malignancy. x30 cancer is more common than polyps
Most polyps are inflammatory.
duodenum - where is most common for adneocarcinoma?
third part
mets to duodenum are from what cancers?
melanoma, breast and lung
most common benign tumour f the stomach
leiomyomas
less common benign cancers of the stomach
Neurilemmomas
Neurofibromas
Vascular tumours (glomus tumours, lymphangiomas, haemangiopericytomas)
Lipomas (these show typical features on cross-sectional imaging of consisting of almost entirely fat)
Carcinoid
Fibromas
Amyloidoma
Hamartomas occur in patients with
Peutz-Jegher’s syndrome (muco-cutaneous pigmentation, increased risk of cancer)
Cowden’s syndrome (multiple hamartomas of the skin and internal organs, fibromas of the skin and particular malignant potential in the thyroid and breast)
Adenomatous polyps occur in patients with:
Familial polyposis coli (the majority of these patients have gastric polyps)
Gardner’s syndrome (osteomas, soft tissue tumours, dental anomalies)
what are the three types of gastric volvulus?
Mesentero-axial
organo-axial
vertical
most common - organo axial. axis from cardia to pylorus
what are the three types of gastric volvulus?
Mesentero-axial
organo-axial
vertical
most common - organo axial. axis from cardia to pylorus
Duodenum divertiucla are assocaited with what?
small bowel overgrwoth and malabsorption
oesophagus - what level does striated uscle turn into smoth muslce?
around aortic arch - xzone of transition
Achalasia is characterised as…..
aperistalsis of the oesophagus with associated lower oesophageal dysfunction.
reduced ganglionic cells in myenteric plexus.
radiographic appearance of oesophagus onf nutcracker syndrome
normal
myenteric plexus can also become damaged simulating achalasia in
chronic Chagas’s disease
Chagas’s disease is by
Trypanosome cruzi and is endemic in Central and South America. Reduvid bug.
How does scleraderma affect the bowel?
Scleroderma is an autoimmune condition that leads to the atrophy and fibrosis of the smooth muscle layer of the bowel
dilates the oesohpagus
Technetium-99m (99mTc) as pertechnetate is cleared from the circulation into the
thyroid, the choroid plexus of the brain, the salivary glands and the normal gastric mucosa.
How is octreotide used for neuro endocrine tumours
Octreotide is a synthetic octapeptide analogue of somatostatin which can be chelated using diethylenetriaminepentacetic acid (DPTA) and labelled with 111In to provide a sensitive technique for localisation of neuro-endocrine tumours and their functioning metastases.
FDG is labelled with what for the Nuc med scans
Flu 18
Simple cysts and peoples age
become more frequent in lder age
Simple cysts are associated with other diseases
Tuberous sclerosis
Polycystic kidney disease (approximately 30% of patients also have liver cysts)
Polycystic liver disease (auto-dominant)
Von Hippel-Lindau (VHL) syndrome
Can you list three sonographic criteria that allow this lesion to be called a simple cyst?
Anechoic/water echogenicity
Posterior acoustic transmission
A well-defined or imperceptible wall
Simple cyst on CT - HU should be
10 or less
Simple cyst on MRI
low signal on T1W spin-echo (SE) images, and very high signal on T2W images, as shown in Fig 1.
US appearance of complex cysts
A thick wall
Internal septa
Haemorrhage
Debris
Calcification
Name the types of benign liver cystic lesions?
Biliary cystadenoma
Hydatid
Multiple biliary hamartomas
Where to biliary cystadenomas arise from?
Bile ducts, occur often in the right lobe
Symptoms of biliary cystadenomas?
abdominal pain
Characteristics of biliary cystadenomas?
They are often multilocular and contain internal septa and mural papillary projections, the latter feature of which is highly characteristic.
CT these lesions, which are classically cystic and well defined with internal septa, the septa, cyst walls, and solid components may enhance helping differentiate them from simple cysts.
Risk of biliary cystadenomas?
can have malignant transformation
What is hydatid disease?
Hydatid disease is a multi-system condition effecting the bowel, liver, lungs, spleen, kidney, bone and central nervous system (CNS).
Complications of hydatid?
Jaundice. Other complications include rupture, infection and anaphylaxis.
How does hydatid appear on imaging?
classical appearance is of a large enhancing cyst with calcification and smaller daughter cysts within. Other signs are the water-lily appearance of a collapsed membrane within a larger cyst