Lecture 17 Flashcards
Plain film
Abdomen particularly important for differentiating between densities (light and dark)
- great strengths in spatial resolution- see outlines of bones
- only know kind of where liver, kidneys and spleen are, cant see clearly
CT
reconstruction using Density in cross-section
- X-rays shot through- coronal images
- Negative: radiation (300x-400x more radiation than plane film)
- shows exactly where organs are
- Patients Right side is your Left side
Peritoneum in abdomen
Pariteal lining
Viceral lining- lining organs
-fluid between
Intraperitoneal Organs of the Abdomen
Liver (most of) & Biliary tree (gallbladder) Stomach (all) Some duodenum Colon (most) All small bowel
Retroperitoneal structures of the Abdomen
Kidneys
Adrenals
Pancreas (top of mountain) - In front of SMA
Duodenum- Between SMA and SMV (running from aorta and IVC, respective sides)
Part of the (ascending/descending) colon
Lymph nodes
MRI
elegant
expensive
Not radiation
Distinguisbale large bowel
Air signature - only in poop appearance (bubbly)
-colon
Pain in abdomen
specific organs more likely to present with specific groups of pain
- Liver pain - yellow, throw up
- Gallbladder-severe pain
- Spleen
- Gut - some visible on plain fill, all visible on CT
Liver and Gallbladder Damage/Pain
Liver:
-Intraperitoneal
-very susceptible, as everything from gut drains into liver
1. Trauma
2. Cancer-primary (HCC Hepatocellular cancer) or metastases(spreading form cancer)
3. Cirrhosis (has large prevalance of Hepatocellular cancer)
Gallbladder:
1. Gallstones/Cholecystitis (cause inflammation. can become cancerous)
2. Cancer
Biliary Tree
Portal vein, Hepatic Artery, Bile duct
-come to biliary tree, with Gall bladder production, to drain out common bile duct –> duodenum
Portal Vein: travels from gut –> through liver (for filtration) –> draining into IVC
Liver and Gallbladder symptoms/signs and investigations
Symptoms/signs:
1. Pain (most common. Not normaly associated with liver, only when outercapsule of peritoneum rapdily expands. tender liver only under severe hepatitis.) gallbladder very painful. RIGHT UPPER QUADRENT. ulcer in stomach can imitate
2. Jaundice
3. Abn LFT’s
Investigations:
1. Ultrasound (not first if think is gut). -dependant on age. Ultra sound if
Ultrasound
Black= dont reflect sound waves= moving vessels (e.g. hepatic veins)
Normal Ecotexture of liver (superficial fact)
-done on everyone
-portable machine
-available i pacific islands
-only way for pregnancy
-Ultrasound (not first if think is gut). -dependant on age. Ultra sound if
Location of gallbladder
In gall bladder fossa
- can see common bile duct in pancreas
- won see all of pancreas in x-section as is on angle
Gallstones
Most common problem in Biliary Tree
Right Upper Quadrant pain -10%
-not normally visible on plain film as bilirubin stones. (therefore normally dont do plain film)
-if visible on plain film, usually have calcium
Ultrasound: gallbladder has fluid in it so black echoes bounce back, but black inbetween. Gallstone:
1. Dense blob makes shadow, bouncing back sound waves not letting them be transmitted
2. Inflammation= gall bladder wall thickens(3mmPositive 4. Ultrasound Murphy’s sign: place probe, poke and will cause pain/takes deep breath
CT not good with CT, some wont show up-if same density/attenuation as other organs
-will see secondary signs of cholicysitis/gb inflammation (thickened wall, fluid around fat surrounding gallbladder)
Spleen Damage
- Trauma
- kicked in LUQ and split spleen. Removed spleen. - Cancer ep. Lymphoma
- can essentially never see primary malignancy in spleen. But other cancers can affect all lymphatic organs - Portal Hypertension (enlarges, when not clearing blood from gut, chirrosis and back pressure backs up to make spleen larger)
- Congenital e.g. cysts
Gut Damage
-can mover with mesentery
-upper abdominal pain. thowing up w. upper gut issues.
-iage via CT
-just severe pain/ulcers - do wiggly tube, not CT
-lower gut issues: examine stool/as history re stool
Free Air?
Stomach: Cancer-Primary or Mets
Small Bowel: -throwing up
-Obstruction: bloodthrowing up/ Heamotemesis
-Crohn’s
-Cancer
-Ischaemia
Colon:
Cancer, Infection, Appendicitis
Inflammatory Bowel Disease
Ischaemia
Free air in gut
Two ways to get free air:
1. Trauma - car accidents
2. Gut Perforation- common. relatively easy to identify. Up right chest x-ray plain film, as rises above liver- if abdominal pain and hypertensive will go to CT (highly suscpetive of perforation or cancer/heamotemesis)
-Ultrasound not good for air- too much air, will bounce the sounds around (US good for solid structures, not Gut overall)
If have no Ct: Left LAteral Decubitus film:
lie patient on left side so liver is facing upwards
-can see air above diaphragm in lung
-if air is below diaphragm (between liver and wall of free abdomen) know there is free air
Ct: see slivers sitting in abdominal wall, infront of gut, in retroperitoneum (perforated duodenal ulcer, went Retro and introperitoneally). Also get appearance post-operatively
Left Lateral Decubitus
if have No Ct
lie patient on left side so liver is facing upwards
-can see air above diaphragm in lung
-if air is below diaphragm (between liver and wall of free abdomen) know there is free air
Imaging the Stomach
Symptoms: Pain (ulcers), weight loss (gastric cancer-dont feel like eating) , Haematemesis (throwing up blood)
Abdo X-ray limited (on plain film)
UGI/Barium (contrast study) vs Endoscopy
-Ulcer: pain after eating, relief via antacids. H. Pylori - ulcers of stomach and duodenum. Endoscopy to see if can see H. pylori. Or treat for H. pylori and see if get better. Chronic ongoing problem
Ct next as problem solver - or as 1st exam in older people (hypotensive)
UGI/Barium (contrast study)
-less popular now as CT better
Can see Stomach rugal folds
-see feather mucosal folds of Duodenum
-Jejunum see feather appearance of normal rugal folds
Hiatal Hernia
air behind heart
-cant do anything about it. unless symptomatic (reflux)
Small Bowel UGI symptoms and Investigation
UGI Symptoms:
1. Pain
2. Haematemesis
3. Vomiting (esp obstruction)
-decreased bowel sounds/no bowel movements. Bloating. Distended bowel loops (more than 3cm) - Multiple air fluid levels. Valvular coluventes- mucosal folds of small bowel, all across, -identify it from colon
Investigation:
1. Plain film - Abdo Xray (partially look for free air, predominantly looking for dilated bowel loops)
2. CT (quickly go, especially if older person. Can see SI contrast -fluid filled + having valvular colaventes) vs US (if not sure about SB)
3. Enteroclysis-shows normal distribution of bowel
-small bowel in middle, colon outside. Contrast seen. Can see poop in Right Lower Quadrant.
Right Illiac Fossa Pain
No dilated bowel on plain film
Non-peristalsing tube in RIF
-Only use Ultrasound in abdomen, is searching for Appendicitis (common for under 30/young people)
-see non wiggling non-peristaltic tube. Blind ended finger length
-larger than should be + fat gong into mesentery
-can have calculus in it
-larger than certain size with fluid
-if this tube not seen on US.
1. Operation if higher WBC levels
2. Ct scan - if elderly, where have to distinguish appendicitis from all other possibilities
Colon-Large Bowel Symptoms and Investigations
Symptoms: 1. Altered Bowel habits (blood) 2. PR blood 3. Malaena Colon cancer-No dilated bowel seen on plain film, but has apple core appearance, air fluid levels not meant to be there. CT you see thickening around colon. Investigations: 1. Abdo X-ray 2. colonoscopy 3. Barium Enema (barium up bottom end, then pump air to make double contrast, b/w air and barium, into sigmoid colon and causght by iliac fossa hernia) 4. CT or CT colonoscopy
Peritoneal Spaces
Surrounding Liver, Spleen and Gut
Ascites- most common abn
Causes of Ascites
1. 3rd spacing e.g. CHF (congestive heart failure- less common)
2. Renal Failure and Hepatic Failure (esp)
3. Malignancy sp. Metastases (esp)
Ascites
CHF congestive heart failure - less common
Renal failure
Liver Failure
Trauma
Cancer-metastases
CT scan: not common. peritoneum, in renal failure esp, can be useful to exchange nasty things)
Pancreas Damage
-head is not always seen on same cross section
-blood tests and CT to identify
Pancreatitis (so painful will hit you if use ultrasound Probe) - Lipase and Amylase test.
Cancer: Primary Pancreatic
-islet cell tumour
-metastases
-Cancer biggest worry for elderly, as can stay Silent for long time
Trauma
Diabetes
Inflammation
Kidney Problems
Stones- Calculi Obstruction to ureters Cancer Trauma Vascular Strictures- renal Ht.
Imaging the Kidneys
Abdo X-ray (dont use any more)
-give iodine. but risk of dying
-kidney stones hold up contrast
Intravenous IVU
Ultrasound - look for kidney stones if young
(non contrast) CT scan - may look for kidney stones if old
MR imaging
Painful Heamaturia: Kidney Stones. Worse Male pain when Kindey stones in Ureter.
Non-Painful Heamaturia: Cancer until proven otherwise. - Renal Cell Carcinoma. -sometimes renal cancer can calcify
Adrenal Problems
Adenomas/Malignant Tumours Metastases Trauma Infection e.g. Tb Haemorrhage
Conclusions:
Imaging modalities best for cross sectional images: US, CT and MRI
IV contrast used to enhance: Liver, spleen, Kidneys and Vessels- CT/MRI
Oral contrast: used to enhance Gut-CT
What is the use of Oral contrast?
to enchange the Gut - CT
What are IV contrasts used to enhance?
Liver, Spleen, Kidneys and Vessels
-CT/MRI
What are the Best imaging modalities for Cross-sectional images?
US, CT and MRI
