Chapter 3 Flashcards
Thoracic Cavity characteristics
- bound by the walls of the thorax
- extends from the superior thoracic aperture to inferior thoracic aperture
- diaphragm separates thoracic cavity from abdominal cavity
What does the thoracic cavity contain?
- lungs
- heart
- organs of the respiratory, cardiovascular, and lymphatic systems
- thymus gland
- inferior part of the esophagus
What are the chambers of the thoracic cavity?
- single pericardial cavity (1)
- right and left pleural cavity (2)
What is the mediastinum? What does it contain?
- the space between the two pleural cavities
- contain all thoracic structures expect the lungs and pleurae
What does the respiratory system consist of?
- lungs
- mouth
- nose
- pharynx
- trachea
- bronchi
Trachea Characteristics
- fibrous, muscular tissue
- lies anterior to esophagus
- filled with air in the x-ray
- divides at carina into right and left primary bronchi
Right Primary Bronchus Characteristics
- shorter, wider, and more vertical
- foreign bodies are more able to enter
Alveoli Characteristics
- each alveolar duct ends with alveolar sacs
- oxygen and CO2 is exchanged by diffusion
- millions of alveoli in each lung
Lungs Characteristics
- apex reaches above the clavicles
- rests obliquely on diaphragm
- moves inferiorly during inspiration and superiorly during expiration
- inner layer is the visceral pleura
- outer layer is the parietal pleura
Thyroid Gland Characteristics
- consists of two lateral lobes
- connected at their lower thirds by the isthmus
- isthmus lies in front of the upper part of the trachea
Parathyroid Glands Characteristics
- small ovoid bodies
- two on each side, superior and inferior
Pharynx Characteristics
- located in front of vertebrae
- located behind nose, mouth, and larynx
- serves as a passage for air and food
Larynx Characteristics
- organ of voice
- the laryngeal prominence = adam’s apple
What are the structures in the mediastinum?
- heart
- great vessels
- trachea
- esophagus
- thymus
- lymphatics
- nerves
- fibrous tissues
- fat
What are the general procedural guidelines for a chest x-ray?
- patient preparation
- general patient position
- IR and collimation size
- SID
- ID markers
- radiation protection
- patient instructions
How do you prepare a patient for a chest x-ray?
- remove clothing and artifacts from anatomy of interest
- secure all belongings in a designated manner and location
What is the general patient position for a chest x-ray?
- ambulatory patients: upright or seated erect
- nonambulatory patients:
- determine whether air fluid levels are critical to diagnosis
- may have to substitute a decubitus if patient can’t be upright
What is the IR and collimation size for a chest x-ray?
- lengthwise
- 43cm x 35cm
What is the SID for a chest x-ray? Why?
- 72in
- to minimize magnification of heart
How should you shield a patient during a chest x-ray?
lead shield between between x-ray tube and patient’s pelvis
What are the 4 reasons to do inspiration and expiration for chest x-rays?
- demonstrates pneumothorax
- diaphragm movement
- presence of foreign body
- atelectasis (collapsed lung)
What are the essential projections for a chest x-ray?
- AP
- PA
- lateral (right and left)
- AP oblique (RPO and LPO)
- PA oblique (RAO and LAO)
- AP axial
What is important to remember when doing a PA chest x-ray?
- upright either standing or sitting
- SID is 72in
- chest is on the IR
- top of the IR is 1 1/2 - 2 inches above the shoulder
- CR enters midsagittal plane and level of T7, is perpendicular to IR, lines up to the spine
- exposure is made after breathing in and holding
- clavicles appear less straight
What structures are shown in the PA chest x-ray?
- air filled trachea
- lungs
- diaphragm
- costophrenic angles
- heart
- aortic arch
- clavicles
- scapulae outside the lung fields
- ribs
Explain the procedure of a PA chest x-ray when it is a cardiac study with barium
- barium is thicker than the barium used for the stomach so it goes down slower
- patient holds barium in their mouth until time of exposure
- patient takes a deep breath and then swallows barium, exposure is made at this time
What is important to remember when doing a lateral chest x-ray?
- upright either standing or sitting
- side closest to IR is side on the image and names the type of lateral
- left lateral is used to minimize magnification
- top of the IR is 1 1/2 - 2 inches above the shoulder
- midsagittal plane is parallel to IR
- patient shouldn’t be leaning sideways or bending forward
- CR enters midcoronal plane
- exposure is made after breathing in and holding
What are the structures shown in a lateral chest x-ray?
- heart
- aorta
- left-sided pulmonary lesions (left lateral)
- right-sided pulmonary lesions (right lateral)
- posterior ribs
- sternum
- trachea
- esophagus
- hilar region
- diaphragm
- costophrenic angles
What is important to remember when doing a PA oblique chest x-ray?
- upright either standing or sitting
- top of the IR is 1 1/2 - 2 inches above vertebra prominenes (C7)
- side of interest is farther away
- LAO side of interest: right
- RAO side of interest: left
- CR is perpendicular, enters at level of T7 (scapula)
- exposure is made after breathing in again and holding
- SID is 72 inches
What structures are seen in a PA oblique chest x-ray?
LAO:
* maximum area of right lung field
* thoracic viscera
* anterior portion of left lung
* trachea
* heart
* aorta
RAO
* maximum area of left lung
* thoracic viscera
* anterior portion of right lung
* trachea
* when filled with barium the esophagus
When doing a cardiac series for a PA oblique projection, what is the angle of the oblique?
55 to 60 degrees
What is important to remember when doing a AP oblique projection?
- upright either standing or sitting
- top of the IR is 1 1/2 to 2 inches above the vertebra prominens
- side of interest is close to IR
- RPO side of interest: right
- LPO side of interest: left
- CR is perpendicular to IR
- CR enters 3 inches below jugular notch (T2)
- exposure is done after breathing in again and holding
- SID is 72inches
What are the structures shown in a AP Oblique projection?
- lungs
- trachea
- bronchus
- carina
- vertebral column
- heart
- diaphragm
- costophrenic angle
What is important to remember when doing a AP chest x-ray?
- supine if the patient is too sick or upright
- top of the IR is 1 1/2 - 2 inches above the shoulders
- might have to angle the tube caudad no more than 10 degrees
- get as much distance as possible
- 60 SID okay, but write it down
- clavicles are straighter
- if patient condition is okay, do the same position as PA chest
- CR is perpendicular to IR and enters 3inches below jugular notch
- exposure is made after breathing in again and holding
What structures are seen in a AP chest x-ray?
- horizontal clavicles
- magnified heart and vessels
- shorter lungs
- trachea
What is important to remember when doing a AP Axial projection in the lordotic position?
- upright and ~1ft in front of the grid
- top of the IR is 3inches above the shoulders
- patient is leaning back until shoulders rest on grid
- angle patient 15 to 20 degrees, CR is not angled
- exposure done after breathing in again and holding
- CR enters 3 to 4 cm below jugular notch
What are the structures shown in the AP Axial Projection in the Lordotic Position?
- entire apices
- clavicles above apices and horizontal
What is important to remember when doing a AP axial projection?
- upright or supine
- CR enters T2 and is angled 10 to 20 degrees cephalically and is perpendicular to IR
- collimation is 24 x 30 cm
What structures are shown in the AP Axial projection?
apices below clavicles
What is important to keep in mind when doing a PA Axial projection?
- upright, seated or standing
- IR size: 24 x 30 cm and is centered at the level of the jugular notch
- CR is 10 to 20 degrees cephalad
- collimation is 24 x 30
- patient position is the same as AP chest
What structures are shown in PA Axial Projection?
apices above the clavicles
What is important to remember when doing a AP or PA lateral decubitus position chest x-ray?
- patient is lying either on their right or left side
- to demonstrate fluid, patient should lie on their affected side
- to demonstrate air, patient should lie on their unaffected side
- top of the IR is 1 1/2 - 2inches above shoulders
- place marker on whatever side is up and annotate whatever side is down
- elevate patient body 2 to 3 inches if lying on affected side
- extend arms over head
- anterior or posterior side against the IR
- CR is horizontal and perpendicular to the center of the IR and enters 3 inches below jugular notch for AP
CR is horizontal and perpendicular to the center of IR and below T7 for PA - exposure is done after breathing in again and holding
What structures are shown in AP or PA lateral decubitus positions?
- fluid position
- affected side from apex to costophrenic angle
What is important to remember when doing lateral ventral or dorsal decubitus positions?
- patient is prone or supine and elevated 2 to 3 inches
- top of the IR is at level of thyroid cartilage
- affected side is against the vertical grid
- CR is horizontal and perpendicular to IR
- dorsal decubitus: CR enters 3-4 inches below jugular notch
- ventral decubitus: CR enters at T7
- exposure is made after breathing in again and holding
What structures are shown in the lateral ventral or dorsal decubitus positions?
- shows a change in position of fluid
- reveals pulmonary areas that are obscured by the fluid in standard projections
