Flashcards in Lecture 3: CXR_interpret_STUDENT-2020-EDITED AL Deck (30)
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Justification for CXR
pneumonia (confirmation)
immunosuppressed pt
COPD w/acute exacerbation
foreign body
CHF
aspiration pneumonia
blunt trauma
lung tumor
chest pain
suspected pneumothorax
SOB (severe)
hemoptysis
pulmonary HTN
PE
interstitial lung ds
ICU pt (adm, inv lines, ETT)
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Basic Tissue Densities
• Black =
• Black – air
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Basic Tissue Densities
• Dark gray =
• Dark gray – subcutaneous tissue, fat
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Basic Tissue Densities
• Light gray =
• Light gray – soft tissue (muscles, heart, blood vessels, pus, etc)
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Basic Tissue Densities
• Off white =
• Off white – bone
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Basic Tissue Densities
• Bright white =
• Bright white – metal (pacemakers, surgical clips, bullets, etc)
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Supine
• supine position limits ?
• ________ push is noted- (____________ contents)
• small pleural effusions will layer in ?- can easily be ?
• *Be _______ interpreting supine films!*
• supine position limits full inspiration
• cephalic push is noted- (liver and abdominal contents)
• small pleural effusions will layer in posterior pleural space- can easily be missed
• *Be careful interpreting supine films!*
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Upright position
inspiration is ?
inspiration is greater/better
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Inspiration and Expiration
Good inspiration = ?
Hypoinflation= ?
Good inspiration = hemi diaphragm down to level of posterior 10th or 11th ribs.
Hypoinflation= dome at 7th rib
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• PA (posteroanterior)
• AP (anteroposterior)
Can you explain the two terms????????????
PA:
X-ray beam is entering/exiting =
pt position =
detector position =
heart size =
diaphragm =
AP:
X-ray beam is entering/exiting =
pt position =
detector position =
heart size =
diaphragm =
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Terminology
Position is TREMENDOUSLY important because the following might be affected:
• magnification
• organ position
• blood flow
• *gravitational pull*
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Which view is most preferred?
Why? See other slides
PA & Upright
Well demarcated costophrenic angle + see other slides
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Expiration usefulness
small pneumothorax: expiration will make the lung larger/smaller and more/less dense, and at the same time will relatively make the pneumothorax appear larger/smaller?
small pneumothorax: expiration will make the lung smaller and denser, and at the same time will relatively make the pneumothorax appear larger
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Expiration usefulness
lodged foreign body: “ball-valve phenomenon” – air can move past the object during inspiration, but during expiration (the bronchus gets smaller) and air can not exit around the obj. As a result, the expiration image will show air trapping in the affected lung and a mediastinal shift will occur toward ?
lodged foreign body: “ball-valve phenomenon” – air can move past the object during inspiration, but during expiration (the bronchus gets smaller) and air can not exit around the obj. As a result, the expiration image will show air trapping in the affected lung and a mediastinal shift will occur toward the unaffected side
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Pneumothorax =
supine vs upright?
Where is the first place to look for pneumothorax?
deep sulcus sign =?
Pneumothorax—air positioned between the visceral and parietal pleura
*trauma, subclavian venous catheter, liver biopsy
*spontaneous (bleb rupture)
*metastatic tumors
upright
Where is the first place to look for pneumothorax (UPPER)
deep sulcus sign = costophrenic angle getting deeper? (supine?) ~ look up!!!
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Pleural effusion
Pleural effusion =
Look for:
Causes:
What is the preferred X-ray position (upright or supine)?
Pleural effusion—collection of fluid between the visceral and parietal pleura (~100 mLs to be detected on upright CXR)
Look for (reference image on pg 87 of reading):
blunting of costophrenic angles
increased basilar density (whiteness)
loss of normal lung-hemidiaphragm is noted
Causes: malignancies, pancreatitis (left-sided), cirrhosis (right-sided), CHF (bilateral), pneumonias (40%)
What is the preferred X-ray position? upright
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Mediastinal shifts:
• Tension pneumothorax—the mediastinum is shifted toward the (affected, unaffected) side?
• Atelectasis—collapse of entire lung segment might result in severe volume loss. Will see mediastinal shift toward the (affected, unaffected) side?
• Airway obstruction—mediastinal shift toward the (affected, unaffected) side?
Mediastinal shifts:
• Tension pneumothorax—the mediastinum is shifted toward the unaffected side.
• Atelectasis—collapse of entire lung segment might result in severe volume loss. Will see mediastinal shift toward the affected side.
• Airway obstruction—mediastinal shift toward the unaffected side.
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male vs female CXR?
• nipple shadows → men and women
• overlying breast tissue → accentuate pulmonary vasculature (careful, not to dx as ?)
• can tape BB or other metal object and reshoot film?
compare both sides
infiltrate
?
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Exposure
Overexposure
• Image is white or dark ?
• Easy to see:
• Cannot see:
Overexposure
• Image is dark
• Easy to see: Thoracic spine, clavicles, behind the heart, NG & ET tube placement
• Cannot see: pulmonary vessels in the periphery, small nodules, or fine structures
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Exposure
Underexposure
• Image is white or dark ?
• Easy to see:
• Cannot see:
Underexposure
• Image is white
• Easy to see: pulmonary vasculature (don’t mistake for infiltrate)
• Cannot see: behind the heart, spinal anatomy, or behind hemidiaphragms
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Know the major landmarks: Slides 27-30!
Know the major landmarks: Slides 27-30!
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Silhouette Sign
• very useful in interpreting a CXR
• it helps to determine the location of an abnormality in relation to ?
• RML vs RLL (pneumonias, masses)
- loss of right heart border indicates that the infiltrate is in the ?
- loss of right hemidiaphragm indicates that the infiltrate is in the ?
- loss of left hearth border indicates that the infiltrate is in the ?
- loss of left hemidiaphragm indicates that the infiltrate is in the ?
Silhouette Sign
• very useful in interpreting a CXR
• it helps to determine the location of an abnormality in relation to normal structures
• RML vs RLL (pneumonias, masses)
- loss of right heart border indicates that the infiltrate is in the RML
- loss of right hemidiaphragm indicates that the infiltrate is in the RLL
- loss of left hearth border indicates that the infiltrate is in the lingula of the LUL
- loss of left hemidiaphragm indicates that the infiltrate is in the LLL
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Aspiration pneumonia
Aspiration:
CXR usually performed immediately after ?
F/U should be performed w/in X hrs ?
Aspiration pneumonia
Aspiration: the inhalation of gastric contents
*following seizure, cardiac resuscitation, anesthesia related complication
CXR usually performed immediately after incidence
F/U should be performed w/in 12 hrs
* may take several hours for the gastric contents to react with the lung to cause fluid exudate and an alveolar infiltrate
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Mediastinal mass → ?
Anterior:
Mediastinal mass → widening or bulge in the central soft tissue of the chest
Anterior:
thymoma
thyroid lesions
teratoma
T cell lymphoma
*The 4 Ts*
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Mediastinal mass → ?
Middle:
Mediastinal mass → widening or bulge in the central soft tissue of the chest
Middle:
t. aortic aneurysms
neoplasms
adenopathy
diaphragmatic hernias
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Mediastinal mass → ?
Posterior (lat view):
Mediastinal mass → widening or bulge in the central soft tissue of the chest
Posterior (lat view):
neurogenic (90%)
neuroblastomas
schwannomas
ganglioneuromas
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Systematic approach:
1. Who
2. What
3. When
4. Why
5. Exposure
Systematic approach:
1. Who (correct patient)
2. What (film orientation) → AP, PA, supine, upright
3. When (date)
4. Why (reason for X-ray) → history and PE are extremely important
5. Exposure
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Systematic approach:
A
B
C
D
E
Systematic approach:
Airway
Bones
Cardiac
Diaphragm/mediastinum
Everything else
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***Read Lecture 3 - Essentials of Radiology-Mettler prior to exam!!!***
EX: List of why we do CXRs
***Read Lecture 3 - Essentials of Radiology-Mettler prior to exam!!!***
EX: List of why we do CXRs
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