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Flashcards in Radiology Deck (32)
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1

Radiography (x-ray)

X-ray radiation generated by machine, absorbed by a detector (room unit) or a portable cassette (portable unit) and then "developed"
-->viewable image

2

Ultrasound

Sound waves sent out by a probe, bounce back, creating an image on a monitor

3

CT scan

-Computed tomography
-X-ray radiation sent out in a 3-D fashion and reconstructed by a computer into 3D images
-Usually 3 planes
-->axial, sagittal and coronal planes

4

MRI scan

-Magnetic Resonance Imaging
-Magnetic fields and radio frequency emissions combine to create 3D images, usually in 2-3 planes

5

Nuclear Medicine

-Injecting radioactive isotopes into the body and then imaging their distribution

6

Chest Radiography Indications

-To evaluate for suspected abnormalities:
-->CP, SOB, cough, hemoptysis, traumatic injury, positive TB test
-->Other: following line or tube placement, f/u tx of pneumonia or edema

7

Chest Radiography Advantages

-Excellent evaluation of heart and lungs
-Quick and cheap
-Low radiation dose (10 days of background radiation)

8

Chest Radiography disadvantages

-Does use radiation
-Challenging in large, uncooperative, or pt's with deformities
-Interpretation requires experience

9

What do black areas on a chest x-ray indicate?

-More radiation passes through
-Lucent/radiolucent

10

What do white areas on a chest x-ray indicate?

-More radiation is absorbed
-Opacity/radiodense

11

Initial steps reading chest radiography

1. Double check pt name and DOB
2. Double check side/site
3. Assess image quality
-->Underexposed= too bright
-->Overexposed= too dark
-->Overcropped?
-->Image reversed?

12

How to read a chest radiograph: CXR Anatomy

A- Airway: Trachea & Bronchi
B- Bones
C-Cardiomedistinal: Heart shadow and Hila
D-Diaphgram
E- Effusions/Edema: Pleural spaces
F- Fields: Lung fields
X- Soft tissue/corner shots

13

"Silhouette Sign"

-Borders not visualized between adjacent structures of the same density

14

Differential Dx for Pulmonary infections

-Bacterial
-Viral
-Valley fever
-Pulmonary TB
-Viral bronchiolitis vs. reactive airway dz
-Opportunistic infection
-->Pneumocystis in AIDS pt's

15

Pulmonary TB

-Of significance due to it's worldwide commonality
-Asymptomatic carriers
-Difficult and long tx
-Developing resistance

16

Primary TB Infection

-Can be clinically silent
-Or can look like pneumonia with pleural effusion
-->nonspecific appearance

17

Post-Primary TB: Reactivation/Secondary

-May develop lung cavities particularly in upper lungs
-Often re-ignites due to relative immunocompromised

18

Differential Dx of Lung Cavity

1. TB
2. Other granulomatous infection: Esp. Valley Fever
3. Cancer: Esp. squamous cell carcinoma
4. Inflammatory conditions: Wegener dz

19

Causes of intrinsic atelectasis (Lung collapse)

1. Mucos
2. Aspirated FB
3. Poor inspiratory effort, Hypoventilation
4. Lack of surfactant

20

Causes of extrinsic atelectasis (Lung collapse)

1. Compressing mass=tumor
2. Compressing adenopathy= lymph nodes
3. Misplaced ET tube= R mainstream intubation

21

"lung scarring"

Long term chronic atelectasis

22

Pleural effusion Ddx

-Transudate
-Exudate
-Air: Pneumothorax
-Blood: Hemothorax
-Infection/pus: Pyothorax (empyema)
-Tumor: Primary << pleural metastasis
-Chronic scarring
*Lateral radiography has higher sensitivity than frontal

23

Pleural Plaques

-Soft tissue thickening and calcification
-Can be related to asbestos exposure (found naturally n rock and soil) if bilateral
-Can look similar to or be associated with mesothelioma (primary pleural tumor)

24

Pneumothorax

Accumulation of air in the pleural space

25

Tension pneumothorax signs

-Sudden onset CP, SOB, tachycardia, respiratory distress, ipsilateral decreased breath sounds
-Imminent risk of cardiopulmonary collapse
Tx: needle thoracotomy @ 2nd rib space, MCL

26

Hydropneumothorax

-Pleural effusion + Pneumothorax

27

Cardiogenic Pulmonary Edema

-True CHF!
-Caused by increased hydrostatic pressure @ pulmonary capillary level
-->water forced from high to low pressure

28

Stages of CHF

1. Cardiomegaly
2. Pulmonary venous HTN= pulmonary congestion
3. Pulmonary interstitial edema
4. Pulmonary alveolar edema= pulmonary edema

29

Pulmonary Nodules

-Calcified nodule: Granuloma
-->benign, no further f/u
-Non-Calcified
-->small <= 0.8 cm: f/u until stable for two years
-->Large noodle >0.8 cm: biopsy and/or PET/CT

30

Chest CT Indications

-F/u abnormal findings on chest x-ray
-Accurate measurement of lesions (nodules/masses)
-Unexplained sx's w/ negative CXR
-Chronic lung dz
-Lung CA screening
-Vascular eval (aneurysm, dissection, PE)
-Chest trauma
-Evaluation of mediastinal and hilarious structures or nodes

31

Chest CT advantages

-Excellent eval of most structures
-Fast

32

Chest CT disadvantages

-Higher radiation (6-24 mos. )
-Cost