Ct - Chest And Abdomen, Part 1

Front 1

where is the ligament of treitz

Back 1

between the 4th segment of the duodenum and the jejunum

Front 2

what is the nml small bowel diameter

Back 2

2.5 cm

Front 3

nml wall thickness of small bowel

Back 3

</ = 3mm

Front 4

ct appearance of crohn's dz in small bowel

Back 4

inflammation of bowel wall, mucosa, and mesentary (in skip lesion pattern)
TI often involved
bowel wall enhances with contrast
fistulas
mesenteric abscess

Front 5

ct findings of complete small bowel obstruction

Back 5

bowel diameter >2.5 cm
collapsed bowel distal to obx (= transition zone)

Front 6

ct findings of small bowel ileus

Back 6

diffusely dilated bowel loops, no transition zone b/c everything is dilated

Front 7

what is the most common cause of sbo

Back 7

adhesions (but not commonly seen on ct)

Front 8

risk factors for intussusception

Back 8

seen with lymphoma, lipoma, carcinoma, mets

Front 9

describe appearance of intussusception on ct

Back 9

there is a bowel loop inside the lumen of another bowel loop, creating a target appearance, there is cecal mesentary (fat density) surrounding intussuseptum

Front 10

in sbo, what finding indicates that bowel wall is still viable

Back 10

contrast enhancement of bowel wall

Front 11

what is a closed sbo

Back 11

obstruction on 2 separate ends of bowel wall

Front 12

what causes closed sbo

Back 12

usually from adhesions or hernia

Front 13

on plain film, how to distinguish btwn ileus vs obstruction

Back 13

if you get an upright film, with an ileus, there will be equal air-fluid lvls at dependent portions of bowel loop
in obstruction, these levels are unequal
(picture a manometer)

Front 14

how big does appendix have to be for appendicitis to be considered

Back 14

>6mm

Front 15

describe the anatomy of the paracolic gutters

Back 15

the ascending and descending colon are retroperitoneal. the peritoneum sweeps anteriorly over these portions and extend laterally, forming the paracolic gutter

Front 16

t or f:
most diverticuli are along mesenteric surface

Back 16

true

Front 17

general findings of colitis

Back 17

thickening of bowel wall, if total wall width >3mm when distended
mural thickening with homogeneous enhancement or halo appearance

Front 18

ct findings of ulcerative colitis

Back 18

wall thickening (7-8 mm) with lumen narrowing +/- inflammatory pseudopolyps
no skip lesions, starts in rectum, which is narrowed
OUTER WALL IS SMOOTH!

Front 19

ct findings of general crohn's dz

Back 19

TI and prox colon most often involved
bowel wall thickened (10-20mm)
irregular outer wall

Front 20

difference in ct findings btwn acute active crohn's and chronic dz

Back 20

target/halo sign seen in acute dz
chronic dz = fibrosis and fat prolif

Front 21

ct findings of c diff

Back 21

pancoliits or segmental irregular wall thickening </= 30mm
wall has accordian like appearance

Front 22

what is typhlitis

Back 22

neutropenic colitis
potentially fatal infx of cecum and ascending colon

Front 23

toxic megacolon

Back 23

dilation of colon to 5cm, with thinning of colon wall
--> pneumatosis, perforation

Front 24

`what are the 4 major causes of pneumatosis intestinalis

Back 24

bowel necrosis
mucosal disruption (from PUD, endoscopy, tubes, trauma, IBD)
increased mucosal permeability from immunosup
pulmonary causes (copd, cf, asthma, intubation)

Front 25

cystic pneumatosis

Back 25

well-defined blebs or grapelike clusters with nml tissue surrounding

Front 26

what is a volvulus
what do you see on ct

Back 26

sigmoid colon twists on mesocolon, see "whirl sign"

Front 27

true or false:
centrolobular bronchioles are not visible in healthy pts

Back 27

true

Front 28

can you see the central artery within each lobule

where do these arteries extend to

Back 28

yes

they do not make it to the pleura unless there is atelectasis

Front 29

causes of thickened intralobular septa

describe thickening for each cause

Back 29

lymphangitic spread of CA (smooth or nodular)
interstitial pulmonary edema (smooth)
alveolar proteinosis (smooth thickening with ground glass opacity)
sarcoidosis (nodular if granulomata are present, irregular in fibrotic or end stage)

Front 30

findings of pulmonary fibrosis

Back 30

intralobular interstitial thickening (early, see fine reticular pattern)
honeycombing
traction bronchiectasis
visualization of intralobular bronchioles

Front 31

describe honeycombing

Back 31

fibrosis with lung destruction and disorganization of lung architecture

Front 32

describe traction bronchiectasis

Back 32

dilated bronchi in region of fibrosis

Front 33

causes of fibrosis

Back 33

idiopathic (#1)
collagen vascular dz
drug related
asbestosis
end stage hypersensitivity pneumoniti s
end stage sarcoid

Front 34

describe the pattern of distribution for multiple pulmonary nodules

Back 34

perilymphatic
random
centrilobular

Front 35

describe perilymphatic distribution of pulmonary nodule s

Back 35

nodules near pleural surfaces
large pulmonary vessels and bronchi
interlobular septa
centrilobular regions

Front 36

describe pattern of random distribution of pulmonary nodules

Back 36

involve pleural surfaces
have diffuse, uniform distribution, but are randomly distrubuted throughout the lung structure

Front 37

describe centrilobular distribution of pulmonary nodules

Back 37

spares pleural surfaces
nodules surrounding vessels
no nodules will touch the pleural surface

Front 38

which type of nodular pattern will also have tree in bud

Back 38

centrilobular

Front 39

etiology of tree in bud appearance

Back 39

mycoplasm infx
cf
bronchiectasis

Front 40

what can cause centrilobular nodular pattern

Back 40

small airway dz
endobronchial spread of bronchoalveolar CA
BOOP
TB

Front 41

describe pathophys behind tree in bud

Back 41

mucous, pus in dilated centrilobular bronchioles

Front 42

what things can cause random nodular distribution

Back 42

miliary tb
hematogenous mets

Front 43

what does a consolidation look like on ct

Back 43

obscured pulmonary vessls
air bronchograms
+/- centrilobular nodules

Front 44

ddx of consolidation

Back 44

depends on duration of sx
if acute:
PNA, ARDS, edema, hemorrhage

if chronic:
BOOP, bronchoalveolar CA, chronic eosinophilic PNA

Front 45

what is the difference btwn consolidation and ground glass opacity

Back 45

with ground glass opacity, you can still see the BV
lungs just look hazy

Front 46

ddx for ground glass opacity

Back 46

depends on duration of sx
if acute:
PCP/viral PNA
edema
hemorrhage
acute hypersensitivity pneumonitis

if chronic:
BOOP
bronchoalveolar CA
lipoid PNA
Pulmonary alveolar proteinosis

Front 47

in a pt with acute sx, what does ground glass opacity indicate

and in chronic dz

Back 47

active dz

usually means active dz, but sometimes ground glass opacity can develop 2/2 fibrosis

Front 48

appearance of mets that have lymphangitic spread

Back 48

interlobular septal thickening
peribronchial cuffing
thickened fissures
thin, patchy unilateral distribution

Front 49

appearance of mets that have hematogenous spread

Back 49

randomly distributed small nodules
pleural and fissure thickening
large nodules
bilateral distribution

Front 50

ct findings of idiopathic pulmonary fibrosis

Back 50

intralobular thickening
honeycombing
traction bronchiectasis
subpleural, postero/inferior lung involvement
+/- ground glass opacity

Front 51

NSIP

Back 51

non-specific interstitial PNA

Front 52

ct findings of NSIP

Back 52

ground glass opacitiyes in posterior lung region
spares immediate subpleural lung
reticular formation
traction bronchiectasis

Front 53

ct findings of active sarcoid

Back 53

perilympatic nodules (1-10mm) +/- calcs
pathcy distribution, asymmetric
upper lobe preodominance

Front 54

ct findings of chronic sarcoid

Back 54

irregular septal thickenin g
architectural distortion
ectatic bronchi

Front 55

ct findings of silocosis and coal workers pneumoconiosis

Back 55

perilymphatic nodule s
symmetric distribution
posterior lung fields
superior lobes
mases of nodules or fibrosis in upper lobes
LAD

Front 56

complication of pulmonary alveolar proteinosis

Back 56

nocardia or mycobacterial superinfx

Front 57

describe pathophys of pulmonary alveolar proteinosis

Back 57

filling of alveolar spaces with lipid rich, proteinaceous material, usually idiopathic, but can be 2/2 silica, malignancy or chemo

Front 58

ct findings of pulmonary alveolar proteinosis

Back 58

pathcy or geographic ground glass opacity
smooth interlobular septal thickening in regions of ground glass opacity (= crazy paving)

Front 59

ct findings of hypersensitivity pneumonitis

Back 59

patchy or geographic ground glass opaity
poorly defied centrilobular nodules of ground glass opacitiy
mosaic perfuson from bronchiolar abn
air trapping

Front 60

complications of pulmonary alveolar proteinosis

Back 60

suprainfection with nocardia or mycobacteria

Front 61

etiologies of boop

Back 61

idiopathic
2/2 toxins
drug rxn
autoimmune

Front 62

clinical course of boop

Back 62

progressive sob
fever

Front 63

ct findings of boop

Back 63

patchy nodular consolication/ground glass opacity
peripheral or peribronchial distribution

Front 64

ct findings of histiocytosis

Back 64

centriolobular nodules early in course
cystic lesions late in course
sparing of costophrenic angle
upper lobe predominance

Front 65

who gets lympahgiomyomatosis

Back 65

women of child bearing age who have had spont ptx, sob, cylous pleural effusion

Front 66

ct findings in lymphagiomyomatosis

Back 66

thin walled rounded cysts with intervening nml lung

Front 67

variant of lymphangiomyomatosis

Back 67

women with tuberous sclerosis get the same thing

Front 68

features of high risk pulm nodules

Back 68

irregular, spiculated edge
lobulated contour
air bronchograms
cavitation with cavitary wall (>15 m)
diameter >2 cm

Front 69

presentation of bronchoalveolar carcinoma

Back 69

can present as ground glass opacities or halo sign

Front 70

appearance of hamartoma

Back 70

smooth, rounded
contain either all fat, fat + calcs, or all calcs

Front 71

where is rounded atelectasis usually found

Back 71

posterior paravertebral regions
can be bilateral
seen mostly with pleural effusions or asbestosis

Front 72

describe the comet tail sign
what is it associated with

Back 72

bending and bowing of adjacent bronchi and arteries towards the edge of atelectasis

will see air-bronchograms, displacement of fissures

seen in rounded atelectasis

Front 73

4 key criteria that must be present to dx rounded atelectasis

Back 73

ipsilateral pleural thickening/effusion
contact btwn lung lesion and abnormal pleural surface
comet tail
volume loss in lobe with opacity

if these 4 things not present, do bx

Front 74

describe appearance of halo sign

Back 74

soft tissue attenuation nodule surrounded by less dense rim or halo of ground glass opacity

Front 75

when is halo sign seen

Back 75

aspergillosis
tb
legionella
nocardia
cmv
bronchoalveolar ca
lymphoma m
kaposi
infarction
wegener's

Front 76

describe air crescent sign

Back 76

mass within a cavity

Front 77

when is air crescent sign seen

Back 77

mycetoma
invasive aspergillosis
clot/neoplasm within cavity
echinococcal cyst

Front 78

nml length of adrenal glands

Back 78

4-5 cm long

Front 79

nml thickness of adrenal glands

Back 79

<10 mm

Front 80

what is in a myelolipoma

Back 80

macroctic extracellular fat with interspersed bone marrow elements

Front 81

how to dx a myelolipoma

Back 81

should have same HU as fat

Front 82

differences btwn an adrenal true cyst and pseudocyst

Back 82

true cyst:
lined wiht endothelium/epithelium
density same as fat

pseudocyst :
mass with visible wall
higher density than simple fluid

Front 83

how does adrenocorical ca present most often

Back 83

as cushing's dz

Front 84

ct findings of adrenocortical ca

Back 84

large (>5 cm)
central necrosis and irreg calcs possible
post-contrast shows nodular areas of enancement, central hypoperfusion, delayed washout

Front 85

complication of adrenocortical ca

Back 85

thrombus in renal vein or ivc --> pe

Front 86

differential for adrenal calcifications

Back 86

(the adrenals are like a HAAT on the kidney)
histoplasmosis/hemorrhage
addison's/adenoma
tb

Front 87

clinical presentation of conn's syndrome

Back 87

primary hyperaldo