imaging Flashcards
liver, biliary and pancreatic disease= ultrasound benefits and uses
noninvasive safe and cheap jaundiced patient hepatomegaly or splenomegaly gallstones focal liver disease (lesions greater than 1 cm) general parenchymal disease portal and hepatic vein patency lymph node enlargement
colour doppler ultrasound
demonstrate vascularity within the lesion and the direction of portal vein blood flow
ultrasound contrast agents (liver)
production of micro bubbles can detect blood flow allows the detection of vascularity and abnormal circulation within the liver nodules (specific diagnosis of hepatocellular carcinoma)
hepatic stiffness (transient elastography)
volcity of the transducer beam correlates with hepatic stiffness increased stiffness is associated with worsening liver fibrosis (80% sensitivity and specificity compared to biopsy) limited to not detecting cirrhosis, and not in obese or with ascites
useful in staging of small potentionally opera table pancreatic tumours and bile duct imaging. used to place transmural tubes to drain pancreatic and peripancreatic fluid collections
endoscopic ultrasound
CT use in liver pancreas and biliary tree
Contrast- good for showing the arterial and venous vasculature
lesions and vascular supply of the lesions.
guidance for biopsy and also can detect calcification and used with obese patients
MRI in Liver, BD, Pancreas
focal liver disease
angiography and venography of splanchnic circulation,
Magnetic resonance cholangiopancreatography
This has replaced diagnostic endoscopic retrograde cholangiopancreatography. It can visualise the biliary ducts dn pancreatic ducts with high quality imaging.
Chest X ray of the abdomen
rarely requested
gallstones (but only if they contain more than 10% calcium)
any sort of calcification they will show
radionucleotide imaging
IODIDA scan used for acute cholecystitis
ERCP
endoscopic retrograde cholangiopancreatography
technique outlines the biliary and pancreatic ducts.
Endoscope into he second part of the duodenum and cannulation of the ampulla. contrast is then injected and the patient is screened radiologically. So this is reserved for therapeutic measures such as: common bile duct stones (sphinctotomy complication acute pancreatitis)
biliary drain or stent
brachytherapy treatment for cholangiocarcinoma
percutaneous transhepatic cholangiography
this goes through the skin into the liver and then contrast is inserted and then the biliary anatomy is visualised.
liver biopsy
indications: liver disease hepatomegaly jaundice severe cirrhosis tumours primary and secondary CI: patient refused, prolonged PT greater than 3 sec increased bleeding risk.
Rheumatology imaging X-rays
joint space narrowing, erosions in rheumatoid, calcification in the soft tissue, osteopenia (decreased bone density) or increased bone density (osteosclerosis).
- acute back pain if it is recurrent and persistent associated with neurological signs or if worse at night and associated with fever or night sweats.
- useful in baseline but not diagnostic in inflammatory arthritis
Rheum US
detecting active synovitis in inflammatory arthritis
guide local injections
periarticular structures and soft tissue swellings
DXA scan
low radiation dose scan for bone density and screening and monitoring for osteoporosis.
MRI in rheum
shows bone changes and intra-articular structures in high quality detail
bone marrow oedema
articular and periarticular disease more sensitive
CT in rheum
just going to show calcification little usefulness.
arthroscopy in rheum
visualisation of the joints particularly the knee and the shoulder joint
repair and trimming of medic=scal tears and lose body removal.
PET scan in rheum
Positron emission tomography
uses radionuclides which decay emitting positrons
F- fluorodeoyglucose indicates areas of increased glucose metabolism.
looking for tumours and large vessel vasculitis .
renal imaging plain X ray
renal calcification or radiodense calculi in the kidneys renal pelvis line of the ureters or bladder.
renal imaging= US
benefits of avoiding contrast and also radiation
advantages: biopsy it will provide measurements on which will be the basis of interventional procedures.
suspected renal obstruction- pelcialyceal dilatation
renal mass cystic or solid.
polycystic kidney disease ddx
doppler can detect renal artery perfusion or thrombosis (user dependent)
measure the bladder wall thickness (tumours or stones)
limits if the calculi are too small not great at visualising the ureters
Ct in renal
first line therapy for suspected ureteric colic
renal masses that cannot be seen on Us
staging for renal tumours
lucent calculi that would be not seen on plain film (uric acid stones)
retroperitoneum fro tumours, fibrosis and causes of ureteric obstruction
severe renal trauma
renal arteries (by angiography)
stage bladder cancer
limits radiation and then contrast nephrotoxicity.
MRI renal
renal mass
staging for prostate cancer
gadolinium for MRI angiography renal arteries
initial imaging for a neck lump
ultrasound and fine needle aspiration
imaging for dysphagia
- barium swallow for looking at oesophageal motility and any obstruction. useful for a high lesion *low is barium meal
if endo first in high lesion risk of injury or perforation of esophageal pouch or injury. - endoscopy diagnositic and therapeutic luminal and mural lesions opportunity and treat lesions (botox, stricture dilatation, stent insertion, laser coagulation) first line for low dysphagia
- videofluroscopy- with speech therapist useful high functional dysphagia
- manometry- this assesses pressure in the lower esophagus and peristaltic waves in the esophagus - motility disorders
bird beak appearance on barium swallow
achalasia
adenocarcinoma of the esophagus confirmed by histology what other imaging do you need for staging?
spiral CT chest and abdomen
PET (positron emission tomography) scan
endoscopic ultrasound - intramural vs transmural disease and local lymph node involvement *if PET. CT are negative for mets
laparoscopy= peritoneal deposits if present relative contraindication to aggressive treatment (used if PET/ Ct negative for mets)
ddx for a solitary coin lesion on CXR
parenchymal tumour: benign, lung ca (primary or secondary) lymph node: lymphoma granuloma: TB sarcoidosis abscess hamartoma foreign object
when would you consider CT in a patient with epigastric pain?
if mesentaric ischemia is suspected or a AAA
patient come in with RUQ pain what imaging are you going to do?
erect chest radiograph (viscus organ perforation) or it can show a widened mediastinum suggestive of a aortic dissection
US of the pancreas, common bile duct and gallbladder
dilatation of the common bile duct greater than 6-7 mm
abdominal ultrasound indicated if signs of bowel obstruction or perforation
Riglers sign
when air is present on both the lumenal and peritoneal sides of the bowel wall.
when is an abdominal radiograph useful?
if you are suspecting bowel obstruction
in the context of known inflammatory bowel disease (toxic megacolon)
to look for a foreign body
what could air under the diaphragm be caused by?
peptic ulcer perforation, or duodenal ulcer perforation
bowel perforation
Meckel’s diverticulum
caecal diverticulum or appendicix
what is the management of acute appendicitis?
resus nil by mouth pre-op coverage of abx appendectomy DVT prophylaxis (IM heparin)
complication of appendicitis
appendix mass, sepsis, peritonitis, appendix abcess
can you distinguish between an appendicial mass and abcess?
mass is a phlegmon and an abcess contains pus
CT or ultrasound will normally be able to differentiate between the two.
conservative management for mass, but not abcess
needs surgical mgx
signs of testicular torsion
tender testicle and scrotal erythema
how do you confirm testicular torsion and who do you need to call?
doppler ultrasound (but call theatre before) call surgeons fast 6 hours all you have for testicular torsion.
what sign can you do to distinguish testicular torsion from epididymitis?
elevating the effected testicle will cause relief from pain in epididymitis but not in testicular torsion (positive Phrens)
if there is a positive cremasteric reflex then it is probably not testicular torsion (96%)
process of elimination for abdominal pain in a woman who is menstrual.
mettelschmerz
what causes appendicitis
faecolith or FB
lymphoid hyperplasia of peyer’s patches or fiberous strictures at the base of the appendix or carcinoid tumour (rare) but that is why all appendix are sent for histological analysis.
what is the neurological explanation of pain in appendicitis
difference between visceral and somatic pain.
visceral pain = splanchnic system only senses stretch and spasm
midline gut emborlogically midline organ so pain on visceral peritoneum is thought to be in midline (T10-T11) lesser splanchnic, but when the appendix enlarges then it is reaching the parietal peritoneum which has cerebral spinal inner action which can then be localised to the area of the appendix.
imaging for acute diverticulitis
abdominal CT with contrast- diagnosing and planing future surgery also if suspicion of abcess or patient is seriously ill.
erect chest X ray perforated viscus air under the diaphragm
abdominal radiograph= only useful if bowel obstruction is suspected
premenopausal women with LIF pain what would help you make a diagnosis?
transabdominal and or transnational ultrasound gynaecological cause like a ectopic pregnancy or ovarian cyst
what should you not do in the acute phase of inflamed colon?
colonoscopy and double contrast enema
management in acute phase diverticulitis
analgesia bowel rest clear fluids only IV fluids antibiotics VT prophylaxis monitor
imaging for kidney stones
CT KUB *kidney ureter and bladder
what finding would you expect on a radiograph image of KUB suspecting kidney stones?
stones
hydronephrosis or hydroureter
perinephric fluid
CT- soft tissue rim- differentiate stones surrounded by soft tissue rather than a calcified pelvic vein
tail sign- soft tissue opacity that extends from the stone like a tail - pelvic phlebolith and not ureteric stone.
what is the psoas sign?
it is where one of the two psoas shadows are not visible on plain abdominal radiograph. unrealable as a patient with abdominal pathology can present with this sign like a acute pancreatitis
AAA best for abdominal US
if leaking abdominal CT for planning of surgery.
what imaging would you request if there is a possible colorectal carcinoma what are the different types of endoscopes used and where can you see to?
proctoscopy - transparent dilator to visualise the rectum and anus
rigid sigmoidoscopy - only to sigmoid
flexible sigmoidoscopy- limited bowel prep with sedation
splenic flexure
colonoscopy - far as illeoaceal valve
oesophagogastrodoudenoscopy far as duodenum upper GI bleed
in a suspected colorectal carcinoma what radiological investigations would you consider?
CT colonoscopy
double contrast barium edema
What can you visualise in a CT colonscopy?
The bowel is prepared and then air inflated. It shows the bowel lumen and surrounding structures like the liver and the ovaries
done if patients cannot tolerate an colonscopy or a sigmoidoscopy
double contrast barium enema. How does it work and what can you see?
barium edema given and then pain radiographs are taken, the lumen can be visualised but this procedure is not used frequently
CT is preferred.
