Surgical Recall: 30 - Surgical Radiology

Front 1

What defines a technically adequate CXR?

Back 1

Film must be "RIPE":

- Rotation: clavicular heads are equidistant from thoracic spinous processes

- Inspiration: diaphragm is at or below ribs 8-10 posteriorly and ribs 5-6 anteriorly

- Penetration: disk spaces are visible but no bony detail of spine; bronchovascular structures are seen through heart

- Exposure: make sure all lung fields are visible

Front 2

How should a CXR be read?

Back 2

Check the following:

- Tubes and lines (check placement)

- Patient data (name, date, history #)

- Orientation (up/down, L/R)

- Technique (AP or PA, supine or erect, decubitus)

- Trachea (midline vs deviated, caliber)

- Lungs (CHF, mass)

- Pulmonary vessels (artery or vein enlargement)

- Mediastinum (aortic knob, nodes)

- Hila (masses, lymphadenopathy)

- Heart (transverse diameter should be <1/2 transthoracic diameter)

- Pleura (effusion, thickening, pneumothorax)

- Bones (fractures, lesions)

- Soft tissues (periphery and below the diaphragm)

Front 3

What CXR is better: PA or AP? Why?

Back 3

PA - less magnification of the heart (heart is closer to x-ray plate)

Front 4

Classically, how much pleural fluid can the diaphragm hide on upright CXR?

Back 4

It is said that the diaphragm can overshadow up to 500 cc

Front 5

How can CXR confirm that the last hold on a chest tube is in the pleural cavity?

Back 5

Last hold is through the radiopaque line on the chest tube; thus, look for the break in the radiopaque line to be in the rib cage

Front 6

How can a loculated pleural effusion be distinguished from a free-flowing pleural effusion?

Back 6

Ipsilateral decubitus CXR; if fluid is not loculated (or contained), it will layer out

Front 7

How do you recognize a pneumothorax on CXR?

Back 7

Air without lung markings is seen outside the white pleural line - best seen in the apices on an upright CXR

Front 8

What x-ray should be obtained before feeding via a nasogastric or nasoduodenal tube?

Back 8

Low CXR to ensure the tube is in the GI tract and NOT in the lung

Front 9

What C-spine views are used to rule out bony injury?

Back 9

CT scan

Front 10

What is used to look for ligamentous C-spine injury?

Back 10

Lateral flex and extension C-spine films, MRI

Front 11

What CXR finding may provide evidence of traumatic aortic injury?

Back 11

- Widened mediastinum >8 cm (most common)

- Apical pleural capping

- Loss of aortic knob

- Inferior displacement of left main bronchus; NG tube displaced to the right, tracheal deviation, hemothorax

Front 12

How should a CT scan be read?

Back 12

Cross section with the patient in supine position looking up from the feet

Front 13

How should an abdominal x-ray (AXR) be read?

Back 13

Check the following:
- Patient data: name, date, history number

- Orientation: up/down, left-right

- Technique: A-P or P-A, supine or erect, decubitus

- Air: free air under diaphragm, air-fluid levels

- Gas dilatation (3, 6, 9 rule)

- Borders: psoas shadow, preperitoneal

fat stripe
- Mass: look for organomegaly, kidney

shadow
- Stones/calcification: urinary, biliary,

fecalith

- Stool
- Tubes
- Bones
- Foreign bodies

Front 14

How can you tell the difference between a small bowel obstruction (SBO) and ileus?

Back 14

- In SBO there is a transition point (cut off sign) between the distended proximal bowel and the distal bowel of normal caliber (may be gasless)

- In ileus, the bowel is diffusely distended

Front 15

What is the significance of the air-fluid level?

Back 15

Seen in obstruction or ileus on an upright x-ray; intraluminal bowel diameter increases, allowing for separation of fluid and gas

Front 16

What are the normal calibers of the small bowel, transverse colon, and cecum?

Back 16

Use the "3, 6, 9" rule:

- Small bowel <3 cm

- Transverse colon <6 cm

- Cecum <9 cm

Front 17

What is the rule of 3's for the small bowel?

Back 17

- Bowel wall should be <3 mm thick

- Bowel folds should be <3 mm thick

- Bowel diameter should be <3 cm thick

Front 18

How can the small and large bowel be distinguished on AXR?

Back 18

By the intraluminal folds:

- The small bowel plicae circulares are complete

- The large bowel plicae semilunares are only partially around the inner circumference of the lumen

Front 19

Where does peritoneal fluid accumulate in the supine position?

Back 19

Morison's pouch (hepatorenal recess), the space between the anterior surface of the R kidney and the posterior surface of the R lobe of the liver

Front 20

What percentage of kidney stones are radiopaque?

Back 20

~90%

Front 21

What percentage of gallstones are radiopague?

Back 21

~10%

Front 22

What percentage of patients with acute appendicitis have a radiopaque fecalith?

Back 22

~5%

Front 23

What are the radiographic signs of appendicitis?

Back 23

- Fecalith

- Sentinel loops

- Scoliosis away from the R because of pain

- Mass effect (abscess)

- Loss of psoas shadow

- Loss of pre-peritoneal fat stripe

- Very rarely, a small amount of free air, if perforated

Front 24

What does KUB stand for? What is it?

Back 24

Kidneys, Ureters, and Bladder: commonly used term for a plain film AXR (abdominal flat plate)

Front 25

What is the "parrot's peak" sign?

Back 25

Evidence of sigmoid volvulus on barium enema

Front 26

What is the "bird's beak" sign?

Back 26

Evidence of achalasia on barium swallow

Front 27

What is a "cut off sign"?

Back 27

Seen in obstruction, bowel distention, and distended bowel that is "cut off" from normal bowel

Front 28

What are "sentinel loops"?

Back 28

Distention or air-fluid levels (or both) near a site of abdominal inflammation (eg, seen in RLQ with appendicitis)

Front 29

What is loss of psoas shadow? What does this suggest?

Back 29

Loss of clearly defined borders of the psoas muscle on AXR; loss signifies inflammation or ascites

Front 30

What is loss of the peritoneal fat stripe? What does this imply?

Back 30

Loss of the lateral peritoneal / pre-peritoneal fat interface

- Implies inflammation

Front 31

What is "thumb-printing"?

Back 31

Non-specific colonic mucosal edema resembling thumb indentations on AXR

Front 32

What is pneumatosis intestinalis?

Back 32

Gas within the intestinal wall (usually means dead gut) that can be seen in patients with congenital variant or chronic steroids

Front 33

What is free air?

Back 33

Air free within the peritoneal cavity (air or gas should be seen only within the bowel or stomach); results from bowel or stomach perforation

Front 34

What is the best position for the detection of FREE AIR (free intraperitoneal air)?

Back 34

Upright CXR - air below the right diaphragm

Front 35

If you cannot get an upright CXR, what is the second best plain x-ray for free air detection?

Back 35

Left lateral decubitus, because it prevents confusion with gastric air bubble; with free air both sides of the bowel can be seen; can detect as little as 1 cc of air

Front 36

How long after a laparotomy can there be free air on AXR?

Back 36

Usually 7 days or less

Front 37

What is Chilaiditi's sign?

Back 37

Transverse colon over the liver simulating free air on x-ray

Front 38

What should a post-op abdominal/pelvic CT scan for a peritoneal abscess be performed?

Back 38

POD #7 or later, to give time for the abscess to form

Front 39

What is the best test to evaluate the biliary system and gallbladder?

Back 39

Ultrasound (U/S)

Front 40

What is the normal diameter of the common bile duct with gallbladder present?

Back 40

<4 mm until age 40, then add 1 mm per decade (eg, 7 mm at age 70)

Front 41

What is the normal common bile duct diameter after removal of the gallbladder?

Back 41

8-10 mm

Front 42

What U/S findings are associated with acute cholecystitis?

Back 42

- Gallstones

- Thickened gallbladder wall (>3 mm)

- Distended gallbladder (>4 cm AP)

- Impacted stone in gallbladder neck

- Pericholecystic fluid

Front 43

What type of kidney stone is not seen on AXR?

Back 43

Uric acid (think Uric acid = Unseen)

Front 44

What med should be given prophylactically to a patient with a true history of contrast allergy?

Back 44

Methylprednisolone or dexamethasone; the patient should also receive non-ionic contrast (assoc. w/ 1/5 as many reactions as ionic contrast, the less expensive standard)

Front 45

What is a C-C mammogram?

Back 45

Cranio-Caudal mammogram, in which the breast is compressed top to bottom

Front 46

What is an MLO mammogram?

Back 46

MedioLateral Oblique Mammogram, in which the breast is compressed in a 45 degree angle from the axilla to the lower sternum

Front 47

What are the best studies to evaluate for a pulmonary embolus?

Back 47

- Spiral thoracic CT scan

- VQ scan

- Pulmonary angiogram (Gold standard)