RAD 112_Chest Radiography & Anatomy

CXR

Chest X-Ray - most common abbreviation for chest radiography.

PA

Posteroanterior projection - X-ray beam enters posterior body surface and exits anteriorly.

AP

Anteroposterior projection - beam enters anterior and exits posterior.

RAO

Right Anterior Oblique - patient rotated with right anterior side closest to IR; demonstrates left lung.

LAO

Left Anterior Oblique - patient rotated with left anterior side closest to IR; demonstrates right lung.

SID

Source-to-Image Distance. Standard = 72 inches (183 cm) to reduce heart magnification.

Bony Thorax

Sternum, clavicles, 12 pairs of ribs, 12 thoracic vertebrae.

Vertebra Prominens

Spinous process of C7 - landmark for PA chest.

Jugular Notch

T2-T3.

Xiphoid Process

T9-T10.

Right Hemidiaphragm

Higher due to the liver pushing upward.

Trachea Bifurcation

At T4-T5 into right and left main bronchi; called the Carina.

Carina

Clinically important landmark for ET tube placement - tube should rest 1-2 inches above.

Lung Lobes

Right = 3, Left = 2.

Right Lung Fissures

Horizontal fissure (upper/middle) and oblique fissure (middle/lower).

Left Lung Fissure

Oblique fissure (upper/lower).

Hilum of the Lung

Central area where bronchi, blood vessels, lymph, and nerves enter and exit.

Lingula

Tongue-like projection of the left upper lobe; analogous to right middle lobe.

PA Chest Preference

PA reduces heart magnification and allows scapulae to move out of lung fields.

Erect Positioning

Preferred for chest as it allows diaphragm to move lower, prevents engorgement of pulmonary vessels, shows air-fluid levels.

Breathing Instructions for Chest Radiographs

Second full inspiration - ensures maximum lung expansion.

72-inch SID

Used for chest radiography to minimize heart magnification and increase detail of lung structures.

Standard Lateral Chest

Left lateral - reduces magnification of the heart.

AP Lordotic Chest Projection

Demonstrates the apices of the lungs free from clavicular superimposition.

Pneumothorax Projection

Best demonstrated by lateral decubitus with affected side up.

Pleural Effusion Projection

Best demonstrated by lateral decubitus with affected side down.

COPD

Chronic Obstructive Pulmonary Disease - emphysema, chronic bronchitis, asthma.

CHF

Congestive Heart Failure - enlarged heart, pulmonary edema, fluid in hilar region.

Pneumothorax

Air in pleural cavity; absence of lung markings and visible pleural line.

Pleural Effusion

Fluid in pleural cavity; blunting of costophrenic angles, meniscus sign.

CR Direction for PA Chest

To MSP at T7 (inferior angle of scapula).

CR Direction for Lateral Chest

To mid-thorax at level of T7.

A32

To mid-thorax at level of T7.

Q33

What cassette orientation is used for PA chest on average adult? A33: 14 × 17 inches lengthwise, or crosswise for broad chests.

Q34

How should arms be positioned for PA chest? A34: Rotated forward to move scapulae laterally out of lung fields.

Q35

What kVp is used for chest imaging? A35: High kVp (110-125) with short exposure time.

Q36

Why is a grid used for chest radiography? A36: To reduce scatter and improve image contrast.

Q37

Why is lead shielding important in chest radiography? A37: Protects gonads and reduces radiation exposure.

Q38

How many posterior ribs should be visible on a good inspiration PA chest? A38: At least 10 posterior ribs above diaphragm.

Q39

Which oblique position best demonstrates the heart and great vessels? A39: LAO at 60° rotation.

Q40

Which oblique best demonstrates the right lung? A40: LAO.

Q41

Which oblique best demonstrates the left lung? A41: RAO.

Q42

Which projection is used when patient cannot stand for an erect chest? A42: AP supine or AP semi-erect.

Q43

What CR angle is used for AP semi-erect chest? A43: 5° caudad to prevent clavicles obscuring apices.

Q44

What type of chest projection is used for pediatrics? A44: AP chest with immobilization device (Pigg-O-Stat).

Q45

What does TB stand for? A45: Tuberculosis - patchy infiltrates, cavitation in apices.

Q46

What does ARDS stand for? A46: Acute Respiratory Distress Syndrome - diffuse alveolar damage, ground-glass appearance.

Q47

What does PNA stand for? A47: Pneumonia - inflammation of lung parenchyma with consolidation.

Q48

What does RSV stand for? A48: Respiratory Syncytial Virus - bronchiolitis/pneumonia in infants and children.

Q49

What does PE stand for? A49: Pulmonary Embolism - clot blocking pulmonary artery; wedge-shaped opacity.

Q50

What does CWP stand for? A50: Coal Worker's Pneumoconiosis (Black Lung Disease).

Q51

What is silicosis? A51: Occupational lung disease from silica dust; nodular opacities in upper lungs.

Q52

What is asbestosis? A52: Lung disease from asbestos fibers; associated with pleural thickening, mesothelioma.

Q53

What is atelectasis? A53: Collapse of all or part of lung; increased density with volume loss.

Q54

What is hemothorax? A54: Blood in pleural cavity; fluid density in pleural space.

Q55

What is pneumomediastinum? ***: Air in mediastinum; lucent streaks around heart/structures.

Q56

Difference between bronchiectasis and bronchitis? A56: Bronchiectasis = chronic dilation of bronchi. Bronchitis = inflammation of bronchi.

Q57

What is cystic fibrosis? A57: Genetic disorder with thick mucus secretions; hyperinflation, bronchial thickening on X-ray.

Q58

What is CR for neonate chest imaging? A58: At mammillary line (near T4-T5).

Q59

Why is horizontal beam used for decubitus chest? A59: To detect air-fluid levels.

Q60

What does 'lordotic' mean in chest radiography? A60: Patient leans back; CR perpendicular to IR to project clavicles above apices.

Q61

What projection replaces full lordotic if patient cannot lean back? A61: AP axial chest with 15-20° cephalad angle.

Q62

What projection best demonstrates interlobar fissures? A62: Lateral decubitus chest with horizontal beam.

Q63

What does decubitus mean? A63: Patient lying down with horizontal CR.

Q64

Which decubitus is most common for chest? A64: Left lateral decubitus - best for free air detection under right hemidiaphragm.

Q65

AP lordotic chest is often used to evaluate what? A65: Apices for tuberculosis.

Q66

Purpose of lateral upper airway imaging? A66: Shows larynx/trachea for foreign body.

Q67

What kVp for pediatric chest radiographs? A67: 70-85 kVp.

Q68

Technique adjustment for portable AP chest? A68: Lower SID (40-48 inches), kVp 90-100; heart magnification greater.

Collimation

Reduces exposure, improves contrast.

Projection for foreign body aspiration

PA and lateral chest; inspiratory/expiratory views.

Emphysema

Alveolar destruction; hyperlucent lungs, flattened diaphragms, increased retrosternal space.

Lung abscess

Pus-filled cavity; round opacity with air-fluid level.

Pneumoconiosis

Occupational dust lung disease (silicosis, asbestosis, CWP).

Sarcoidosis

Systemic inflammatory disease; bilateral hilar lymphadenopathy.

Bronchogenic carcinoma

Primary lung cancer; masses, atelectasis, obstruction.

Hyaline membrane disease

Respiratory Distress Syndrome in premature infants; 'ground-glass' lungs.

Pulmonary edema

Fluid in alveoli; 'bat-wing' pattern.

Pneumoperitoneum

Free air under diaphragm (perforated viscus).

Tension pneumothorax

Mediastinal shift opposite side, depressed diaphragm.

Consolidation

Solidification of lung due to alveolar filling (e.g., pneumonia).

Expiratory chest films

Detect pneumothorax, foreign body, compare lung inflation.

AP axial of upper airway

Larynx, trachea for airway narrowing (e.g., croup).

ET tube

Endotracheal tube; tip 1-2 inches above carina.

NG tube

Nasogastric tube; extends into stomach.

CVP catheter

Central Venous Pressure catheter - tip in SVC.

PAC catheter

Pulmonary Artery Catheter (Swan-Ganz) - tip in right pulmonary artery.

PICC line

Peripherally Inserted Central Catheter - tip in SVC.

Chest radiographs for line/tube placement

Ensures correct position, detects complications.

Cardiomegaly

Enlarged heart; cardiothoracic ratio >50% on PA chest.

Motion blur in chest imaging

Breathing/heartbeat motion blurs lung markings and heart borders.

ARDS

Acute Respiratory Distress Syndrome - diffuse 'ground-glass' lungs.

PNA

Pneumonia - consolidation, air bronchograms.

TB

Tuberculosis - affects apices; cavitary lesions.

Silhouette sign

Loss of normal border between lung and soft tissue (e.g., heart border).

Pulmonary fibrosis

Scarring of lung tissue; irregular opacities, honeycombing.

Pleural plaque

Thickened pleura from asbestos exposure.

Pulmonary nodule

Small round opacity, benign or malignant.

Metastatic disease appearance

Multiple 'cannonball' nodules.

Pneumomediastinum

Air in mediastinum - trauma, rupture, barotrauma.