radiographic procedures - CHEST

Chest

What body structures does the bony thorax consist of?

(Anteriorly) - Sternum (manubrium, body, xiphoid process), Superiorly 2 Clavicles, 2 Scapulae, Posteriorly - 12 pairs of ribs, 12 thoracic vertebrae (T1-T12), costal cartilages

What are the topographic landmarks for chest positioning?

Jugular Notch (level of the upper margin for AP at about T2); Vertebral Prominence (Level of C7 for PA)

What are the 4 divisions of the respiratory system?

Pharynx, (Nasopharynx - posterior to the nose, oropharynx - posterior to the mouth , laryngopharynx - above and posterior to the larynx), Trachea, Bronchi, Lungs

The Thyroid gland is located…

at the level of C5-C6

What is the carina?

The internal prominence or ridge in which the trachea bifurcates into the L and R bronchi

What is the difference between the L and R bronchi?

Right bronchus is shorter, wider and more vertical - and is likely the bronchus food may get stuck in; Left bronchus is longer and more slender

Roughly how many alveoli are in the two lungs and what is their function?

Approx. 500-700 million alveoli; Oxygen and carbon dioxide are exchanged in the blood through the thin walls of the alveoli.

How many lobes in the right lung? How many in the left lung? What are they seperated by

Right lobe - 3 (superior, middle, inferior) lobes divided by 2 fissures (Horizontal fissure separates superior and middle lobe, Oblique lobe separates middle and inferior lobes)

Left Lobe - 2 (superior, inferior) lobes, separated by a single deep oblique fissure

What is the bony thorax?

The skeletal framework of the chest involved with breathing and blood circulation. (Protective cage)

What is the Thoracic Viscera?

The internal organs located within the thoracic cavity - Heart, Lungs, Trachea, Esophagus, Thymus Gland, Major Blood Vessels

What is Respiration?

The exchange of gaseous substances between the air we breathe and the bloodstream

What is the Diaphragm?

The primary muscle of inspiration (inspiration - lungs filling with air)

What is the Pharynx

Serves as a passageway for food and air; part of respiratory and digestive system

Where is the pharynx located?

Posterior area between the nose and the mouth; Superior to the larynx and esophagus

Where is the Esophagus located?

Posterior to the larynx and trachea

What is the Larynx

a cage-like cartilaginous structure that is suspended from the Hyoid bone; it is the organ of voice and houses the vocal cords.

Where is the larynx located?

in the anterior portion of the neck; upper margin is C3, lower margin is C6 - where it joins with the trachea.

What is the larynx made up of?

Thyroid cartilage - (forms the anterior wall) largest and least mobile. Prominent anterior projection = laryngeal prominence = adams apple —> located at the level of C4 - C5

Cricoid Cartilage - (forms the inferior and posterior wall of the larynx) is attached to the first ring of the cartilage of the trachea

Epiglottis - Flips down and acts as a “lid” over the trachea during the act of swallowing to prevent food from entering

Where is the trachea located?

Anterior to the esophagus; Extend downward from the level of C6 to the level of T4 or T5

Connects the larynx to the main bronchi

Divides at the carina (the last tracheal cartilage) into the R and L primary bronchi

Which structure is more radiosensitive than most body structures or organs?

Thyroid gland

Where is the thymus gland located?

Inferior to the thyroid gland; anterior and superior to the heart

What do AP and Lateral radiographs allow for?

visualization of the air-filled trachea and larynx

What is Parenchyma?

A light, spongy, highly elastic substance that allows for the breathing mechanism responsible for expansion and contraction of the lungs.

Pleura

A double-walled sac or membrane that completely encloses the lung

Parietal Pleura

The outer layer that lines the inner surface of the chest wall and diaphragm

Pulmonary or Visceral Pleura

Inner layer that covers the surface of the lungs

Pleural Cavity

The space between the 2 pleura that contains a lubricating fluid and allows movement of one or the other lung during breathing.

Pericardial Sac

Membrane that surrounds the heart

Radiographically Important Parts of the Lungs (Hint 5 things)

Apex / Apices - the rounded upper area above the level of the clavicles. Extends up into the lower neck area of T1

Carina - The lowest margin of the separation of the trachea into the L and R bronchi

Base - The lower concave area of each lung that rests on the Diaphragm (Diaphragm separates the thoracic and abdominal cavities)

Costophrenic Angles - The extreme outer most lower corner of each lung, where the diaphragm meets the ribs.

Hilum (Hilus) - The central area of each lung, where the bronchi, blood vessels, lymph vessels and nerves enter and leave the lungs.

Mediastinum

The medial portion of the thoracic cavity between the lungs.

Radiographically important structures of the Mediastinum (hint 4)

Thymus Gland - located behind the upper sternum; prominent in children, but may not appear on adults because of less dense, fatty tissue

Heart and Great Vessels - Heart is located posterior to the body of the sternum and anterior to T5-T8; Great Vessels include the Superior/ Inferior Vena Cava, Aorta, and Pulmonary Arteries and Veins

Trachea - separates into the L and R bronchi

Esophagus - Posterior to the trachea and continues down through the mediastinum anterior to the descending aorta, until it passes through the diaphragm into the stomach

ABC’s of Chest X-rays

A - Airway / Assessment of Image Quality

B - Bones / breathing

C - Cardiac silhouette and size

D - Diaphragm (hemi-diaphragms)

E - Everything else (Equipment, Effusions)

F - Field size, lung fields

G - Great vessels

H - Hilum

RIPE for Image Quality

R - Rotation - clavicles and spine should be equidistant

I - Inspiration - at least 10 pairs of posterior ribs should be seen

P - Projection - What type of projection is it?

E - Exposure - should see lung apices, costophrenic angles, and thoracic vertebrae

3 Dimensions increased with Inspiration

Vertical Diameter - increased primarily by contraction and downward movement of the diaphragm, increasing thoracic volume

Transverse Diameter - The ribs swing upward and outward, which increases the diameter of the thorax

Anteroposterior Diameter - Increased by the raising of the ribs, especially the 2nd - 6th rib.

Describe body habitus from largest / widest to thinnest / longest

Hypersthenic - Hyper = Heavy - Wide; Large, broad, deep body; short, wide lungs; high diaphgram

Sthenic = Standard - Average; Average build, Average Organ position

Hyposthenic - PO = below, hypo - below standard - Slim and slender, longer lungs, lower diaphragm (hypo = low organs)

Asthenic = A stick or stick figure; very skinny, thin, frail; long, narrow thorax, lowest diaphragm

As body gets thinner, thorax gets longer, diaphragm gets lower

In chest x-ray, what does strict collimation do?

Reduces patient dose, Improves image quality

Which x-ray is the most common with the highest number of repeats?

Chest X-ray

What factors should a radiographer take extra care in when producing chest radiographs?

Positioning

Central Ray (centered)

Collimation (strict)

Correct Exposure factors

What should the kVp be for chest x-rays?

110-125

What does high kVp require?

The use of grids

What is the mA and exposure time for chest radiographs?

High mA

Short exposure time - minimizes the chance of motion and loss of sharpness

What is Situs Inversus (visceral inversion)

When the major organs of the body are on the opposite side.

Give a reason why anatomic side markers must be placed on the IR prior to exposure

Situs Inversus

Legal Issues

What technical factors should you consider with a pediatric patient?

Lower kVp (70-85)

Less mAs

Shortest exposure time possible to prevent motion

Use immobilization device, such as a Pigg-o-stat

What might you consider when dealing with a geriatric patient?

Higher CR (T6-T7) due to less inhalation capability and smaller lung fields

May require different exposure requirements due to pathologies / pathologic conditions

More care, time, and patience when explaining breathing and positioning requirements

Arm supports for lateral positions

What are 3 reasons chest radiographs should be taken in an Erect position?

1) The diaphragm is able to move down farther

2) Air and Fluid levels are better visualized (Air rises, fluid sinks)

3) Engorgement and Hyperemia of pulmonary vessels may be prevented (Erect positioning minimizes these while supine increases them)

Engorgement

Distended or swollen with fluid

Hyperemia

An excess of blood that results, in part, from relaxation of the distal small blood vessels or arterioles.

What should the SID be for Chest radiographs?

72

Primary difference between AP and PA projections for chest images?

AP - results in magnification of the heart / heart shadow

PA - results in less magnification and less divergence from the x-ray beam

What is a definable standard?

Every radiographic image can be evaluated to dtermine where improvements can be made

What does rotation do to a chest x-ray

Slight rotation results in distortion of the size and shape of the heart shadow because the heart is located anteriorly in the thorax

How can you tell if the patient has been rotated in a PA projection?

Sternoclavicular joints / ends of the clavicle should be the same distance from the center of the spine. If rotated, the clavicle closest to the spine is the direction of rotation.

Why is a L lateral the standard (for Lateral Chest)

Because the heart is on the left side and you want to minimize magnification

Positioning Requirements for PA

Chest to IR

Hands on hips, palms out

Shoulders rolled forward

Chin up and out of the way

Positioning Requirements for Lateral

Left side against IR

Arms Raised (Arms out, clap and clasp hands, bend elbows, lift up and over head)

Weight distributed evenly on both feet to prevent tilt and rotation

Midsagittal plane parallel to the IR

How can you identify rotation on a Lateral Chest X-Ray

Separation of posterior ribs should be only ¼ to ½ inches; anything greater indicates rotation of the thorax.

PA Central Ray location

Perpendicular to IR and centered to midsagittal plane at the level of T7 (approx. 7-8 inches below the VP or to the inferior angle of scapula)

Adult Female - approx. 7 in below VP

Adult Male - approx. 8 in below VP

Athletic Sthenic / Hyposthenic - Aprox. 9 in below at level T8

Hypersthenic - approx. 6-7 in below VP

What vertebra level is the Vertebra Prominens located (approx)

T1 (upper margin of the apex of the lungs)

AP Central Ray location

Jugular Notch - upper margin

Average Adult - 3-4 inch below Jugular Notch (for a level of T7)

Geriatric or hypersthenic - approx. 3 inch below Jugular Notch

Younger / Sthenic / Hyposthenic - aprrox. 4-5 inch. below Jugular Notch.

Anterior Oblique Positions: RAO and LAO - Chest

Side of interest is the side FURTHEST from the IR —> a RAO best visualizes the LEFT lung

LAO best visualizes the RIGHT lung

Describe the angle for Oblique positions - chest

Rotated 45 degrees

More than 45 degrees - for studies of the heart and great vessels

Less than 45 degrees - for visualization of the lungs in pulmonary disease

What pathologies do Oblique positions look for - chest AP or PA

Investigate pathologies related to the lung fields, trachea, and mediastinal structures

Determine the size and contours of the heart and great vessels

Posterior Oblique

Side of interest is CLOSEST to the IR

LPO - the right lung is elongated because it is furthest from the IR

RPO corresponds to the LAO; LPO corresponds to the RAO

What does an AP lordotic position of the chest look for?

Calcification and masses beneath the clavicles

What is an alternate position for the lordotic, if the patient cannot stand?

AP semi-axial projection in the supine position with the CR 15-20 cephalad

For an AP Supine Chest x-ray, what is the direction of the CR?

CR is angled caudad to be perpendicular to long axis of sternum at the level of T7

What are the technical factors for an Upper Airway Projection - Lateral

SID - 72 in

kVp - 75-85

Field Size - Portrait

CR - perpendicular to center of the IR at the level of C6 or C7; midway between the laryngeal prominence of the thyroid cartilage and the jugular notch

Respiration - Slow, deep, inhale

Collimate - to soft tissues of the neck

What are the technical factors for an AP projection of the upper airway?

SID - 40 inches

Field Size - Portrait

kVp - 75-85

Acanthiomeatal line is perpendicular to the IR

CR - perpendicular to the IR at the level of T1-T2

Respiration - slow, deep, inhale

What pathologies do the Upper Airway projections look for?

Investigate pathology of the air-filled larynx and trachea, including the region of the thyroid and thymus glands, and upper esophagus for opaque foreign objects.

Atelectasis

Collapsed lung

Caused by puncture / blowout of air passageway

Radiodense lung regions with shift of heart and trachea (in severe cases)

Increase Exposure

PA and Lateral Projection

Bronchiectasis

Irreversible Dilation of the Bronchioles

Most common in the lower lobes

PA and Lateral with CT

Radiodense lower lungs

No exposure adjustment

Bronchitis

Acute (short term) or chronic (long term)

PA and Lateral

Caused by smoking, virus, or bacteria

Hyperinflation (general radiolucency) and dominant lung markings of the lower lungs

No exposure adjustment

Cystic Fibrosis

Common Inherited Disease

PA and Lateral

Increased radiodensities in specific lung regions

Increased Exposure Adjustment

Emphysema

COPD; irreversible and chronic, alveoli destruction

PA and Lateral

Barrel - chest, increased lung dimensions, flattened diaphragm, radiolucent lungs

Decrease Exposure (significantly, depending on severity)

Lung Neoplasm

Growth or Tumor

PA, Lateral, CT

Benign - Radiodensities with sharp outlines; may be calcified radioplaque)

Malignant - slight shadows in the early stages; large radiopaque masses in later stages

No exposure adjustments

Occupational Lung Diseases

Anthracosis - caused by deposits of coal dust; small opaque spots throughout lungs

Asbestosis - inhalation of dust fibers; calcification (radiodensities) involving the pleura

Silicosis - inhalation of silica quarts (form of sand dust)

PA and Lateral

No exposure Adjustment

Pleural Effusion

Accumulation of fluid in the pleural cavity

Erect PA, Lateral or Lateral Decubitus with the AFFECTED SIDE DOWN (horizontal beam)

Increased radiodensities, air-fluid levels, possible mediastinal shift

Increase Exposure

Types of Pleural Effusion

Hemothorax - blood

Empyema - Pus

Pleurisy

Inflammation of the pleura surrounding the lungs

PA and Lateral

Possible Air - fluid levels; none with dry pleurisy

No exposure adjustement

Pneumonia

Inflammation of the lungs that results in accumulation of fluid

PA and Lateral

Patchy infiltrate with increased radiodensity

No exposure adjustment

Pneumothorax

Air in the pleural space that can cause the lung to collapse

Erect PA or lateral, lateral decubitus with AFFECTED SIDE UP, if small, PA inspiration and expiration for comparison

Lung displaced from chest wall; no lung markings

No exposure adjustment

Pulmonary Edema

Associated with congestive heart failure, excess fluid within the lung

PA and Lateral; horizontal beam for air-fluid levels

Radiodensities in hilar regions;

Increase Exposure Factors in severe cases

Tuberculosis

contagious disease caused by airborne bacteria

Primary - PA and Lateral, opaque spots throughout lungs; enlargement of the hilar region, no exposure adjustments

Secondary - PA, Lateral, AP Lordotic, regions of calcification frequently in upper lobes and apices, upward retraction of hila, Exposure adjustments none or increase slightly

What is the name of the structure that acts as a lid over the larynx to prevent foreign objects such as food particles from entering the respiratory system?

Epiglottis

What is the term for the small air sacs located at the distal ends of the bronchioles, in which oxygen and carbon dioxide are exchanged in the blood?

Alveoli

Which bone is seen in the anterior portion of the neck and is found just below the tongue or floor of the mouth?

Hyoid Bone

What is the name of the prominence, or ride, seen when looking down into the trachea where it divides into the right and left bronchi?

Carina

The Carina is approx. at the level of which vertebra?

T5

The delicate, double - walled sac or membrane that contains the lungs is called

the pleura

The Lower concave portion of the lungs is called

The base

Central area in which bronchi and blood vessels enter the lung is called

the hilum

Upper, rounded portion above the level of the clavicles is called

The apices / apex

Extreme, outermost lower corner of the lungs is the

costophrenic angles

Why is the right hemidiaphragm positioned higher than the left?

Because the liver is located in the right upper abdomen and pushes up on the right hemidiaphragm

What is the aorta and what are the 3 parts of it?

Aorta - the largest artery in the body that carries blood to all parts of the body

Ascending Aorta - comes up and out of the heart

Arch of the Aorta

Descending Aorta - passes through the diaphragm into the abdomen where it becomes the abdominal aorta

What is a common radiographic sign seen on a chest radiograph for a patient with respiratory distress syndrome (RDS)

Air Bronchogram Sign

Name the pathologies where you would need to increase your exposure settings

Atelectasis

Cystic Fibrosis

Pleural Effusion

Pulmonary Edema

Respiratory Distress Syndrome

Secondary TB

Name the pathologies you would decrease exposure factors

Aspiration (mechanical obstruction)

Emphysema

Epiglottitis

Aspiration

Mechanical obstruction due to swallowing a foreign object