4.2: Week 4 pt 2

Question 1

In current medical practice, the __________ has largely come to replace the plain film in evaluation of the abdomen

Answer 1

CT scan

Question 2

Describe The quick and systematic XR read

Answer 2

1: Look at the overall gas pattern
2: See if there is extraluminal air
    : :shudders:: . . . not a good thing at alllll
(There is a whole chapter on this, so we’ll get to it later)
3: Look for abnormal abdominal calcifications
4: Look for any soft-tissue masses

Question 3

Describe what the large bowel looks like on CXR

Answer 3

It is peripheral & has prominent and widely spaced haustral markings

Question 4

Describe normal amt of air in small bowel

Answer 4

Expect to see a little air in 2-3 loops
Normal is about the size of a quarter

Question 5

Describe the normal amt of air in the large bowel

Answer 5

Almost always air in distal colon or rectum
Varied amounts of air in remainder of colon is normal too
You should also be able to recognize stool; lots of little bubbles among soft tissue density

Question 6

How big is a normal colon?

Answer 6

About 3 inches

Question 7

What are the 2 main parts of looking at the overall gas pattern?

Answer 7

A: Look at air and stool distribution
-Does it look normal?
B: Look for AIR FLUID LEVELS

Question 8

What air fluid levels are normal in the abd?

Answer 8

It is normal to see 2-3 air fluid levels in the small intestine
Totally normal in the stomach
You really should NOT see them in the colon

Question 9

What are phleboliths? What do they look like?

Answer 9

They’re small and round and are caused by venous thrombi that calcify with age
Because of their smallness and roundness, they look like kidney stones

Question 10

Calcified rib cartilages:
1) Who is it more common in?
2) What can they look like?

Answer 10

1) More common in women, esp over 35
These are actually used to help determine gender in postmortem eval
2) In addition to not being kidney stones, these are also not gallstones

Question 11

You have two tools for evaluating a mass on XR; what are they?

Answer 11

1) Directly see the border, which you can only do if its not silhouetted by something else massive. . . Which happens a lot
(The abdomen is packed tight)
2) Look for indirect displacement of something
i.e. “It’s so big it’s pushing x, y, z all the way over here”

Question 12

How do you eval for splenomegaly on XR?

Answer 12

If it extends past the 12th rib
If it pushes the stomach’s gastric bubble past midline

Question 13

L kidney is about the size of the ____

Answer 13

spleen

Question 14

Describe the bladder on XR and what’s above it

Answer 14

The dome is often visible
Just above bladder: uterus / colon in women, colon in men
If enlarged, look for displaced bowel

Question 15

Describe the uterus on XR

Answer 15

If enlarged it might be caught on x ray, but this eval is typically done with U/S
Fat plane separates

Question 16

What is a Supine (AKA Flat Plate or KUB) view good for?

Answer 16

Great for looking at overall gas pattern
May also identify masses or calcifications

Question 17

Prone View helps to view what?

Answer 17

Helps see gas in ascending and descending colon
Because these are posterior (along with retrosigmoid) they will collect gas in this position

Question 18

What is an upright view helpful with?

Answer 18

Good for seeing air beneath the diaphragm
Can evaluate air fluid levels

Question 19

When would you use Left lateral Decubitus? What would you see?

Answer 19

Substitute view for upright, when patients cannot tolerate standing or sitting
In this view, free air should be visible on the outside edge of the liver

Question 20

What is the use of CT in diagnosing pathology in the abd/pelvis?

Answer 20

Nontraumatic, unexplained abd pain
Has greatly decreased the need of “exploratory” surgery
Best way to view the differences in densities of the abd structures/tissues to best define the anatomy

Question 21

Should you always use contrast for CT?

Answer 21

CTs can be performed with or without contrast agents (IV or PO) depending on what you are looking for

Question 22

CT scans:
1) ______ is much easier to define when contrast is used
2) Define enhanced CT

Answer 22

1) Anatomy
2) CT w IV contrast

You can order w or w/o contrast (institution dependent) or radiologist will determine based on what is being evaluated and what you are trying to determine

Question 23

IV contrast:
1) Who determines rate?
2) Who cannot have IV contrast?

Answer 23

1) Radiologist will determine the rate of contrast as needed per patient which will show for example hepatic vessels before hepatic parenchyma
2) Those with compromised renal function with
Cr > 1.5mg/dl cannot have IV contrast (think DM, HTN, dehydration, CKD…)
If erroneously given, can cause ATN (acute tubular necrosis.)

Question 24

IV contrast can also cause side effects such as?

Answer 24

Feeling of warmth flowing throughout the body
n/v
Itching and hives
Irritation @ injection site

Question 25

When do you use PO contrast? How is it given?

Answer 25

Can be used in abd/pelvic CTs to define bowel Given in divided dosages to define stomach and colon simultaneously.

Question 26

What are the 2 types of PO contrast? When is each used?

Answer 26

1) Barium sulfate 2) Gastrographin (water soluble): used when possible bowel perforation or any time contrast may have a possibility of leaking outside of the bowel wall.

Question 27

How can PO contrast be administered?

Answer 27

Either can be administered via NGT, enema or via foley to the bladder.

Question 28

Indications for PO contrast in CT abd/pelvis include?

Answer 28

1) Nontraumatic abdominal pain 2) Inflammatory bowel disease 3) Abdominal or pelvic abscess 4) Locate the site of bowel perforation, including fistulae (how would you order this one?)

Question 29

Ultrasounds; list the: 1) Uses 2) Advantages 3) Disadvantages

Answer 29

1) Primary imaging mode for gallbladder, biliary tree and female pelvis, screening for aortic aneurysms, identification of vascular abnormalities and flow. Detection of ascites/fluid/cysts. 2) Readily available, relatively low cost, no ionizing radiation, easy to tolerate, can be portable 3) Operator dependent, difficult to delineate anatomy, not for obese patients

Question 30

What is the diagnostic modality of choice for most abdominal abnormalities, including trauma?

Answer 30

CT scan (but non- contrasted here)

Question 31

CT scans; list the: 1) Uses 2) Advantages 3) Disadvantages

Answer 31

1) Diagnostic modality of choice for most abdominal abnormalities, including trauma (but non- contrasted here) 2) Usually available, lower cost than MRI More detailed image reconstruction Can evaluate multiple organ systems simultaneously 3) Higher cost than U/S, uses ionizing radiation, inability to use intravenous contrast in renal insufficiency, possibility of contrast reactions

Question 32

MRIs; list the: 1) Uses 2) Advantages

Answer 32

1) Can give different view/perspective and help solve difficult diagnoses Shows extension of known disease into surrounding soft tissues (staging) Shows vascular anatomy 2) High soft-tissue contrast, no ionizing radiation No iodinated contrast – uses gadolinium (less side effects,) image reconstruction in many planes

Question 33

List the disadvantages to MRIs

Answer 33

Usually highest cost of imaging modalities, Limited availability, longer scan times, loud Claustrophobia; patient weight and size may preclude study – some patients need pre-meds Monitoring issues in acutely ill patients Incompatible with certain medical devices or foreign bodies in/on patient

Question 34

What should the liver look like on CT?

Answer 34

Should have smooth surface and homogenous texture

Question 35

Liver: 1) What occurs at the parenchyma? 2) When does the liver mostly enhance?

Answer 35

1) Blood from portal vein delivers nutrients and allows liver to filter blood prior to it entering systemic circulation 2) In the portal venous phase.

Question 36

On contrasted CT scans the spleen, what does it look like?

Answer 36

initially appears homogenous but then lobulations will start to appear.

Question 37

Descr pancreas on CT

Answer 37

Retroperitoneal Lays oblique, so can’t see entire organ on any 1 axial image Head snugs up to duodenal loop

Question 38

Descr the kidneys on CT

Answer 38

Normal Kidneys. The kidneys (K) lie in the renal fossae bilaterally. The normal renal sinus, containing fat, occupies the central portion of the kidneys The right renal artery runs posterior to the inferior vena cava (IVC). The left renal vein lies anterior to the left renal artery

Question 39

Typically, a renal CT will be imaged in a series of ______ intervals after IV contrast is given to highlight different sections of the kidney

Answer 39

timed

Question 40

Descr the Normal Small and Large Bowel on CT

Answer 40

1) Contrast fills a nondilated SB lumen (<2.5 cm). 2) The small bowel wall is so thin that it is normally almost invisible (white arrows). 3) The terminal ileum can be recognized by the fat-containing “lips” of the ileocecal valve (black arrows) outlined with orally administered contrast in the lumen.

Question 41

Where is the urinary bladder?

Answer 41

In females – located anterior to vagina and anteroinferior to the uterus In males located superior to prostate and anterior to rectum Ureters enter posterolateral at trigone

Question 42

Descr a normal urinary bladder on CT

Answer 42

The urinary bladder (B) contains unopacified urine in this early image of a contrast-enhanced CT scan of the pelvis. The bladder wall is thin and of equal thickness around the circumference of the bladder. The rectum lies posterior to the bladder