Surgical Radiology, C30 P183-190 Flashcards Preview

Section I, Surgical Recall Sixth Edition > Surgical Radiology, C30 P183-190 > Flashcards

Flashcards in Surgical Radiology, C30 P183-190 Deck (46):
1

CHEST
What defines a technically
adequate CXR?
P183

The film must be “RIPE”:
Rotation: Clavicular heads are
equidistant from the thoracic
spinous processes
Inspiration: Diaphragm is at or below
ribs 8–10 posteriorly and ribs 5–6
anteriorly
Penetration: Disk spaces are visible
but there is no bony detail of the
spine; bronchovascular structures
are seen through the heart
Exposure: Make sure all of the lung
fields are visible

2

CHEST
How should a CXR be read?
P184

Check the following:
Tubes and lines: Check placement
Patient data: Name, date, history
number
Orientation: Up/down, left-right
Technique: AP or PA, supine or
erect, decubitus
Trachea: Midline or deviated, caliber
Lungs: CHF, mass
Pulmonary vessels: Artery or vein
enlargement
Mediastinum: Aortic knob, nodes
Hila: Masses, lymphadenopathy
Heart: Transverse diameter should be
less than half the transthoracic
diameter
Pleura: Effusion, thickening,
pneumothorax
Bones: Fractures, lesions
Soft tissues: Periphery and below the
diaphragm

3

CHEST
What CXR is better: P-A or A-P?
P184

P-A, less magnification of the heart (heart
is closer to the x-ray plate)

4

CHEST
Classically, how much pleural
fluid can the diaphragm
hide on upright CXR?
P184

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

5

CHEST
How can CXR confirm that
the last hole on a chest tube
is in the pleural cavity?
P184

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

6

CHEST
How can a loculated pleural
effusion be distinguished from
a free-flowing pleural effusion?
P184

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

7

CHEST
How do you recognize a
pneumothorax on CXR?
P184

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

8

CHEST
What x-ray should be obtained
before feeding via a nasogastric
or nasoduodenal tube?
P184

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

9

CHEST
What C-spine views are used
to rule out bony injury?
P184

CT scan

10

CHEST
What is used to look for
ligamentous C-spine injury?
P185

Lateral flex and extension C-spine films,
MRI

11

CHEST
What CXR findings may
provide evidence of
traumatic aortic injury?
P185

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

12

CHEST
How should a CT scan be
read?
P185 (picture)

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

13

ABDOMEN
How should an abdominal
x-ray (AXR) be read?
P185

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

14

ABDOMEN
How can you tell the
difference between a small
bowel obstruction (SBO) and
an ileus?
P186

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), whereas
the bowel in ileus is diffusely distended

15

ABDOMEN
What is the significance of
an air-fluid level?
P186 (picture)

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

16

ABDOMEN
What are the normal
calibers of the small bowel,
transverse colon, and
cecum?
P186

Use the “3, 6, 9 rule”:
Small bowel < 6 cm
Cecum < 9 cm

17

ABDOMEN
What is the “rule of 3s” for
the small bowel?
P186

Bowel wall should be < 3 mm thick
Bowel folds should be < 3 mm thick
Bowel diameter should be < 3 cm wide

18

ABDOMEN
How can the small and large
bowel be distinguished on
AXR?
P186

By the intraluminal folds: The small
bowel plicae circulares are complete,
whereas the plicae semilunares of the
large bowel are only partially around the
inner circumference of the lumen

19

ABDOMEN
Where does peritoneal fluid
accumulate in the supine
position?
P186

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

20

ABDOMEN
What percentage of kidney
stones are radiopaque?
P186

≈90%

21

ABDOMEN
What percentage of
gallstones are radiopaque?
P187

≈10%

22

ABDOMEN
What percentage of patients
with acute appendicitis have
a radiopaque fecalith?
P187

≈5%

23

ABDOMEN
What are the radiographic
signs of appendicitis?
P187

Fecalith; sentinel loops; scoliosis away
from the right because of pain; mass
effect (abscess); loss of psoas shadow;
loss of preperitoneal fat stripe; and, very
rarely, a small amount of free air, if
perforated

24

ABDOMEN
What does KUB stand for?
P187

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

25

ABDOMEN
What is the “parrot’s beak”
or “bird’s beak” sign?
P187

Evidence of sigmoid volvulus on barium
enema; evidence of achalasia on barium
swallow

26

ABDOMEN
What is a “cut-off sign”?
P187

Seen in obstruction, bowel distention,
and distended bowel that is “cut-off”
from normal bowel

27

ABDOMEN
What are “sentinel loops”?
P187

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

28

ABDOMEN
What is loss of the psoas shadow?
P187

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

29

ABDOMEN
What is loss of the peritoneal
fat stripe (a.k.a. preperitoneal
fat stripe)?
P187

Loss of the lateral peritoneal/preperitoneal
fat interface; implies inflammation

30

ABDOMEN
What is “thumbprinting”?
P187

Nonspecific colonic mucosal edema
resembling thumb indentations on AXR

31

ABDOMEN
What is pneumatosis intestinalis?
P187

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

32

ABDOMEN
What is free air?
P188 (picture)

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

33

ABDOMEN
What is the best position for
the detection of FREE AIR
(free intraperitoneal air)?
P188

Upright CXR—air below the right
diaphragm

34

ABDOMEN
If you cannot get an upright
CXR, what is the second
best plain x-ray for free air?
P188

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

35

ABDOMEN
How long after a laparotomy
can there be free air on AXR?
P188

Usually 7 days or less

36

ABDOMEN
What is Chilaiditi’s sign?
P188

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

37

ABDOMEN
When should a postoperative
abdominal/pelvic CT scan
for a peritoneal abscess be
performed?
P188

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

38

ABDOMEN
What is the best test to
evaluate the biliary system
and gallbladder?
P188

Ultrasound (U/S)

39

ABDOMEN
What is the normal diameter
of the common bile duct
with gallbladder present?
P189

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

40

ABDOMEN
What is the normal common
bile duct diameter after
removal of the gallbladder?
P189

8 to 10 mm

41

ABDOMEN
What U/S findings are
associated with acute
cholecystitis?
P189

Gallstones, thickened gallbladder wall
( >3 mm), distended gallbladder ( >4 cm
A-P), impacted stone in gallbladder neck,
pericholecystic fluid

42

ABDOMEN
What type of kidney stone is
not seen on AXR?
P189

Uric acid (Think: Uric acid = Unseen)

43

ABDOMEN
What medication should be
given prophylactically to a
patient with a true history of
contrast allergy?
P189

Methylprednisolone or dexamethasone;
the patient should also receive nonionic
contrast (associated with one fifth as
many reactions as ionic contrast, the less
expensive standard)

44

ABDOMEN
What is a C-C mammogram?
P189 (picture)

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

45

ABDOMEN
What is an MLO mammogram?
P190 (picture)

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

46

ABDOMEN
What are the best studies to
evaluate for a pulmonary
embolus?
P189

Spiral thoracic CT scan, V-Q scan,
pulmonary angiogram (gold standard)