Final exam Flashcards
How does one view a lateral projection?
Lateral projections, which are marked by R or L by side of patient closest to the IR, are viewed from the same perspective as the x-ray tube or by the radiologist’s preference.
How does one view a PA or AP oblique projection?
The same way a true PA or AP is viewed: with the patient’s right to the viewer’s left.
How does one view a decubitus chest and/or abdomens?
The way the x-ray tube “sees” them.
How does one view upper and lower limbs?
As if you were looking from the x-ray tube. Images that include digits placed with digits up. Other images of limbs viewed in the anatomical position.
How are CT or MRI images viewed?
Axial images are generally viewed so the patient’s right side is to the viewer’s left.
What are exposure factors (technique)?
The three exposure variables that are set on the control panel of the x-ray machine by the radiographer each time an image is produced. (kV, mA, seconds)
ALARA
As low as reasonably achievable
What is the name of the measurement of radiation in the air?
Roentgen (R)
What is the name of the measurement of radiation used for patient dose purposes?
Rad
What is the measurement term used for worker protection purposes?
Rem
What is the SI unit corresponding to Roentgen?
Coulombs/kg of air
What is the SI unit corresponding to Rad?
Gray (Gy)
What is the SI unit corresponding to Rem?
Sievert (Sv)
What are precautions taken for pregnant technologists?
A second monitoring device is issued for fetal monitoring. The mother does not have to alter her work schedule.
What is the recommended maximum equivalent does to the fetus of a pregnant technologist?
0.05 rem (50 mrem, .5 mSv) per month and .5 rem (500 mrem, 5 mSv) for the gestational period.
Types of personnel monitoring:
film badge, TLD (thermoluminescent dosimeter), & OSL (optically stimulated luminescence).
Where are dosimeters worn?
At waist or chest level or on collar during fluoroscopy.
What are ALARA principles?
Always wear a personnel monitor, radiology personnel should not restrain patients, Use sound radiographic exposure factors, and follow the cardinal rules of radiation protection, which are Time, distance and shielding.
Fluoroscopy safety practices are:
Bucky slot cover, lead drape, .5 mm lead apron, exposure limit of 10 R/min.
Ways to protect the patient during exam:
Minimum repeat radiographs, give clear instructions, use proper positioning and exposure factors, including correct filtration and close four sided collimation, specific area shielding, protection for pregnancies.
Types of collimators
Manual and Positive-beam limitation (PBL)
Types of shielding:
Shadow shields and contact shields.
Properties of Gonadal contact shields:
1mm lead equivalent, reduces dose 50% to 90%.
Center for Devices of Radiologic Health guidelines for gonadal shielding:
- If the gonads lie within or close to the primary x-ray field (about 5 cm from) despite proper beam limitation.
- If the clinical objective of the exam is not compromised.
- If the patient has a reasonable reproductive potential.
NHTI student rules concerning radiation protection of the student.
Students should NEVER hold a patient during exposure.
NEVER take an x-ray unless ordered by a qualified health care practitioner.
Always wear dosimeter badges at the clinic site.
Lead aprons MUST be worn during fluoroscopy and mobile radiography!
OSL badges must be brought to NHTI and worn during labs when exposures are being made.
Divisions of chest anatomy
Bony thorax, Respiratory system, Mediastinum.
Bony Thorax protects:
and consists of:
Protects the thoracic viscera and consists of Sternum, clavicles, scapulae, 12 pairs of ribs and 12 thoracic vertebrae.
The two bony landmarks used for chest positioning are:
The vertebra prominens, located at C7, and the jugular notch, located at T2-T3.
The xiphoid tip corresponds with:
the anterior portion of the diaphragm at T9-T10, but is not a reliable landmark for positioning.
Function of the respiratory system:
Exchange of gaseous substances between the air and the blood.
Divisions of the respiratory system:
The pharynx (not part of the respiratory system proper), the larynx, the trachea, the bronchi and the lungs.
The diaphragm is:
the muscular partition separating thoracic cavity from abdominal cavity.
Each half of the diaphragm is called:
hemidiaphragm.
Respiratory movement of the diaphragm is about —- between inspiration and expiration.
1 and a half inches.
The effect of deep inspiration on the diaphragm is:
the diaphragm lowers to its lowest level.
Basic properties of the pharynx:
It is the “throat.” It is about 5 inches long. Posterior to the nasal and oral cavities. Superior to larynx. Anterior to cervical vertebrae.
Three divisions of the pharynx:
Nasopharynx, oropharynx, laryngopharynx.
The Nasopharynx:
Superior portion of the pharynx, lies posterior to nasal cavity and extends to plane of soft palate.
The Oropharynx:
Intermediate portion on the pharynx, likes posterior to oral cavity and extends from uvula to hyoid. Has both respiratory and digestive functions.
The Laryngopharynx:
Inferior portion of pharynx, begins at level of hyoid bone, connects esophagus with larynx, both a respiratory and digestive pathway.
Esophagus:
Part of digestive system, connects pharynx to stomach, posterior to larynx and trachea.
Respiratory system proper comprised of:
Larynx, Trachea, right and left bronchi, and the lungs. Pharynx serves as a passage for air and food, and therefore not part of the respiratory system proper.
First division of the respiratory system proper is:
the larynx.
The larynx’s location is:
Midline of neck, anterior to C3-C6 and suspended from the hyoid bone.
Thyroid cartilage:
2 fused plates of cartilage that forms anterior wall of larynx.
Prominent anterior projection of thyroid cartilage is:
Laryngeal prominence. A.k.a.: the adam’s apple. Located at C5.
Epiglottis:
Large leaf-shaped piece of cartilage in the larynx. “Stem” is attached to anterior rim of thyroid cartilage. “Leaf” portion is unattached and flips down to cover trachea during act of swallowing.
Cricoid cartilage:
Ring of cartilage that forms the inferior and posterior wall of larynx. Attaches to first ring of cartilage of trachea.
Basic info of the trachea
A.k.a. the “windpipe.” Tubular passageway for air. 5 inches long, anterior to esophagus, shifted slightly to R of midline due to arch of aorta.
Location of trachea:
Extends from larynx, C6 to T4-T5 where it divides into the R&L primary bronchi.
What is the trachea made up of?
20 C-shaped rings of cartilage that are embedded into it’s walls, which prevent the trachea from collapsing during inspiration.
Thyroid gland location:
Just inferior to larynx. R&L lobes of thyroid gland lie on either side of trachea.
Why is it important for radiographers to know the location of the thyroid gland?
Because it is very radiosensitive.
Describe the parathyroid glands:
4 raisin-sized glands embedded in the posterior surface of the thyroid gland– 2 in each lobe of they thyroid. They are endocrine glands that secrete hormones that aid in specific blood functions.
Location of the Thymus gland:
just distal to the thyroid gland.
AP projection of the upper airway demonstrates:
the air filled trachea and larynx, possible enlargement or abnormalities of thyroid, and possible Airway system pathology.
Lateral projection of the upper airway demonstrates:
Air filled trachea and larynx, region of the esophagus, general location of both thyroid gland and thymus gland.
Where does the trachea divide into the left and right main bronchi?
T4-T5.
Describe the differences between the right and left bronchi:
The right is wider and shorter and more vertical.
Describe the carina:
Specific prominence or ridge of the last tracheal cartilage. Site of where the trachea divides into the R&L bronchi.
Why is the location of the carina significant to radiological techs?
It is used in portable chest radiography to aid in endotracheal tube placement.
How to the R&L main bronchi divide further?
The right bronchus divides into three secondary bronchi and the left divides into a secondary bronchi. Each secondary bronchi enters individual lobes of the lung.
How many lobes are in each lung?
Three lobes in the right lung, two lobes in the left.
What do secondary bronchi divide further into?
bronchioles.
What is at the end of each terminal bronchiole?
alveoli
How many alveoli do the two lungs contain?
Between 500-700 million alveoli
What is the main function of alveoli?
Oxygen and carbon dioxide are exchanged by diffusion within the walls of the alveoli.
Where are the lungs located?
On each side of the thoracic cavity.
Where do the lungs extend to and from?
From the diaphragm to just slightly superior to the clavicles.
Anatomical location of lungs:
Lie against ribs anteriorly and posteriorly. The rounded apex reaches above the clavicles. The broad inferior portion of each lung is the base. The base is concave and fits over convex area of diaphragm.
How many lobes is the right lung made up of?
Three. Superior, middle, and inferior lobes.
What are the names of the fissures of the right lung?
Horizontal and oblique.
How many lobes is the left lung made up of?
Two. Superior and inferior.
What is the name of the left lung’s fissure?
Oblique.
The left lung has no horizontal fissure and no middle lobe. The portion of the left lobe that corresponds imposition to the right middle lobe is called the:
lingula.
Lungs are composed of light, spongy, highly elastic substance called the:
parenchyma.
What allows for breathing mechanism responsible for expansion and contraction of lungs which brings oxygen into and removes carbon dioxide from blood through alveoli?
Parenchyma.
What is the pleura?
A double-walled, serous membrane that encloses each lung. The “walls” are the parietal pleura, which is the outer layer, and the visceral pleura, which is the inner later.
What does the parietal pleura attach to?
The wall of the thoracic cavity.
What does the visceral pleura cover?
The surface of the lungs, including dipping in between fissures and lobes.
What is the pleural cavity?
The potential space between parietal and visceral pleura. It contains serous fluid to prevent friction between membranes.
Pneumothorax:
an accumulation of air in the pleural cavity resulting in collapse of the lung. May result in partial or complete collapse of lung.
What is a pleural effusion?
Accumulation of fluid in the pleural cavity.
What is a hemothorax?
When it is blood that is creating the pleural effusion.
What is empyema?
When the fluid creating the pleural effusion is pus.
What is pleurisy?
inflammation of the pleura. Visceral and parietal pleura “rubbing” during respiration.
What is the best projection/position to show fluid levels of a pleural effusion on a chest radiograph?
Lateral decubitus position with the affected side down, or the erect position.
What is emphysema?
An irreversible and chronic lung disease, in which alveolar air spaces become greatly enlarged as a result of alveolar wall destruction and loss of alveolar elasticity.
How does emphysema present on a radiograph?
Increased lung dimensions, depressed and flattened diaphragm, obscuring costophrenic angles, elongated heart shadow, radiolucent lung field.
If it is known that the patient has emphysema, how should one adjust exposure factors?
Emphysema requires a decrease in exposure factors from a normal chest.
What is the pericardial sac?
A double-walled membrane that surrounds the heart.
What does the heart look like in a CT image?
The heart takes up about a quarter of the image, it is the the left of the MSP and anterior to the MCP. The esophagus is posterior to the heart and the descending aorta is between the esophagus and the thoracic vertebrae.
What can be seen on a PA chest if the technical factors are set optimally?
The lungs and other soft tissues as well as the bony thorax.
What are the radiographically important parts of the lungs?
Apex, carina, base, diaphragm, costoprhrenic angles, hilum.
Why are most lateral chest radiographs done with the left side closest to the IR?
To reduce magnification of the heart.
When looking at a left lateral chest x-ray, one can only see the left lung. Therefore, how many lobes are seen?
Two.
When looking at a left lateral chest x-ray, some of the lower lobe of the left lung extends above ———– posteriorly, whereas some of the upper lobe extends below ——–anteriorly.
The hilum (in both cases).
The posterior part of the diaphragm is the most ——— part of the diaphragm.
inferior
The right lung is usually about 1 inch shorter than the left because ———.
the liver pushes up on the right hemidiaphragm.
The mediastimum is:
the medial portion of thoracic cavity between lungs.
The four structures of the mediastinum are:
Thymus gland, heart and great vessels, trachea, esophagus.
Describe the thymus gland:
Primary control organ of lymphatic system. It consists of 2 lobes that lie in the lower next and superior mediastinum posterior to the sternum.
At maximum development, thymus gland lies where?
Above and anterior to heart and pericardium, behind the upper sternum.
Can the thymus be seen in middle aged adults?
No, the thymus is a temporary organ, prominent in infants. Reaches its maximum size at puberty and gradually atrophies until it almost disappears as in adult.
Heart and great vessels are enclosed in what?
The pericardium.
The heart is posterior to:
the sternum.
The heart is anterior to:
T5-T8
2/3 of the heart lies where?
To the left of the MSP.
Great vessels include:
superior and inferior vena cava, aorta, pulmonary arteries and veins.
What does the superior vena cava do?
Returns blood to the heart from upper 1/2 of the body.
What does the inferior vena cava do?
Returns blood from lower 1/2 of body.
What does the aorta do?
As the largest artery in the body, it carries blood to all parts of the body through its various branches.
What three sections are the great vessels divided into?
Ascending aorta, aortic arch, and the descending aorta.
As the aorta passes through the diaphragm, it becomes:
the abdominal aorta.
What do the pulmonary arteries and veins do?
Supply blood and return blood to and from all segments of the lungs.
The part of the trachea within the mediastinum does what?
Bifurcates into the right ad left primary bronchi.
Where is the proximal esophagus located?
Posterior to trachea and continues through mediastinum anterior to descending aorta.
True or false: The pharynx is a common passageway for both food and respiration.
True
The “Adam’s apple” is formally referred to as the
Laryngeal prominence
The trachea extends from C6 to approimately
T5
The outermost layer of the pleura is referred to as the
parietal pleura
Which of the following is not a mediastinal structure? Thymus gland Esophagus Trachea Epiglottis
Epiglottis
What is body habitus?
Refers to the common variations in the shape of the human body. It is based on a 1917 study by WR Mills of 1000 patients.
How is body habitus used in radiology?
Body habitus determines size, shape, and position of organs in thoracic & abdominal cavities.
Body habitus directly affects the location of which organs?
Heart, lungs, Diaphragm, Stomach, Large intestine, Gallbladder.
What are the four types of body habitus?
Sthenic
Hyposthenic
Asthenic
Hypersthenic
What does one need to keep in mind when taking an image of a hypersthenic person?
Massive build, thorax is broad side to side, thorax is deep front to back, and thorax has shallow vertical dimensions.
What does on need to keep in mind when taking an image of an asthenic person?
Slender build, thorax narrow from side to side, thorax shallow from front to back, thorax is very long in vertical dimension.
During inspiration, the thoracic cavity increases in what three dimensions?
Vertical diameter (Diaphragm moves downward and increases thoracic volume.), transverse diameter (diameter ribs swing outward and upward) anterioposterior diameter by raising the ribs; especially ribs 2-6.
How many ribs should one see on a good PA chest radiograph?
a minimum of 10.
How is a patient prepped for a radiograph?
Removal of opaque objects, clothing artifacts, long hair fasteners, and O2 lines and pacemaker leads not in lung fields.
The higher the kVp, the more:
Greys.
Technical factors for a chest x-ray (concerning kV):
kVp between 110-125 demonstrates many shades of grey needed to visualize lung markings. Low contrast, long scale contrast, and high kV requires use of grids.
Technical factors for a chest x-ray (concerning mAs):
High mA & short exposure times reduces motion. Sufficient mAs is needed to provide optimum density of lungs and mediastinal structures.
Optimal density for a chest x-ray:
Able to see faint outlines of at least mid and upper vertebrae and posterior ribs through the heart and other mediastinal structures.
Placement of film markers on a chest x-ray:
Top lefthand corner. “L”
Pediatric Applications for chest xray. Newborns:
AP supine or dorsal decubitus.
Pediatric Applications for chest xray. When child can support own head:
Erect PA and laterals. Use Pigg-o-Stat.
Technical factors for pediatric chest xray:
Lower kVp 60-70, less mAs, shortest exposure time possible (to reduce motion.)
Geriatric applications for a chest xray: CR location:
A little higher CR location may be required because older patients have less inhalation capacity (center around T6-T7).
Common geriatric pathologic conditions of chest are:
pneumonia and emphysema.
Pneumonia:
inflammation of lungs resulting in an accumulation of fluid within certain sections of the lung creating increased radiodensities in these regions. Generally requires some increase in exposure factors to penetrate and visualize these areas.
Emphysema:
Alveoli become enlarged because of alveolar wall destruction and loss of elasticity. Air tends not to be expelled during exertion. Causes: smoking and long term dust inhalation. Radiographically evident by increased lung dimension. Lung fields radiolucent. Requires decrease in exposure factors from normal chest.
Instructions on patient handling for geriatric patients:
More care, time, and patience is frequently required in explaining breathing and positioning requirements. Helping and supporting theses patients in the positioning process is important. Arm supports for lateral projection.
Breathing instructions:
Hold breath on second “full” inspiration. Not “deep,” which will cause distortion.
Indications for full inspiration and full expiration comparison radiographs:
small pneumothorax
fixation or lack of movement of diaphragm
presence of foreign body
distinguish between opacity in rib or lung
atelectasis
Atelectasis:
A condition in which collapse of all or portion of a lung occurs as a result of an obstruction or the bronchus, or a puncture of an air passageway. With less than normal air in the lung, this region appears more radiodense and may cause the trachea and heart to shit to the affected side.
Reason for erect chest position:
- Allows diaphragm to move down farther.
- Demonstrates air-fluid levels (Minimum of 5 mins allows fluid to settle or air to rise).
- Prevents engorgement and hyperemia of pulmonary vessels.
Minimum SID for erect chest position:
72 inches to minimize heart magnification of heart and to obtain greater recorded detail of the delicate lung structures.
A 72 inch SID magnifies less because:
the X-ray beam has less divergence. (Picture the shadow of your finger as you move the flashlight closer and then further away.)
Chest radiographs if taken AP rather than PA at 72 inches will cause:
increased magnification of the heart shadow.
Placing heart closer to film for PA projection results in:
less magnification.
Goal of evaluation criteria:
Optimal radiograph.
What is evaluation criteria?
Definable standard so every chest radiograph can be evaluated.
Signs of rotation in a PA projection:
Clavicles will not be equidistant from the spine. Whichever clavicle is closest to the spine is the direction of the rotation.
Sufficient neck extension ensures:
chin will not superimpose upper lung region.
Patients with large pendulous breasts should be asked:
to pull the breasts upward and laterally. Have the patient hold the breasts in place by leaning against the IR.
For a lateral chest position, place the side of interest:
Closest to the IR.
For routine lateral chest postioning:
Left side is closest to the IR.
The separation of posterior ribs resulting from beam divergence at 72 inches should only be (what distance?)
1/4 to 1/2 inches or about 1 centimeter.
Direction of rotation on a lateral can be determined by identifying:
the gastric air bubble in stomach or by ID’ing inferior border of heart shadow. Both are associated with the left hemidiaphragm.
Tilt on a lateral chest X-ray would be demonstrated by:
closed intervertebral disk spaces.
Why are arms raised high during a lateral chest X-ray?
To prevent superimposition of the humerus and soft tissue of humerus on the upper chest field.
What two bony landmarks can provide a consistent and reliable means of determining CR location for chest X-ray?
Vertebra prominens and jugular notch.
CR chest positioning method: verterbra prominens corresponds to:
Level of T1 and uppermost margin of apex of lungs.
After palpating the vertebra prominens:
Measure 7 inches down for females, 8 inches down for males to determine proper CR location.
Exceptions to positioning the CR at T7:
Larger, athletic females may have longer lung fields, and some males may have shorter lung fields. Some well-developed athletic sthenic/hyposthenic type men require centering closer to T8 or 9 inches down from vertebra prominent.
The level of T7 on average adults is ——–below the jugular notch.
3-4 inches
The level of T7 on older or hypersthenic patients is:
3 inches below the jugular notch.
The level of T7 on younger or on sthenic/hyposthenic athletic types is:
4-5 inches below the jugular notch.
IR placement depending on lung dimensions (AP or PA projections):`
Tech determines whether the IR should be placed lengthwise or crosswise based on body habitus. Apices to costophrenic angles must be included.
Digital chest units may include larger IR’s. True or false?
True. This eliminates the crosswise vs lengthwise concern.
It is recommended that most AP recumbent chest X-rays are done:
crosswise, due to an increased chance that the side of chest would be “clipped” with lengthwise IR.
PA chest collimation guidelines:
Adjust field margins to outer skin margins, remembering that the chest expands during inspiration. Adjust the upper border of the illuminated field to the vertebra prominens.
Digital Imaging Considerations.
Collimation:
*reduces dose
*ensures optimal quality of processed image by reducing scattered radiation from reaching CR or CR IR’s
Alows computer to provide accurate information regarding exposure index number.
Digital Imaging Considerations.
Accurate centering:
Because of the technique used by the CR or DR image receptor, it is important that the body part and CR be accurately centered to the IR.
Digital Imaging Considerations.
Exposure factors:
Digital imaging systems are known for their wide exposure latitude; they are able to process an acceptable image from a broad range of exposure factors (kV and mAs). Radiation protection: ALARA; use highest kV with lowest mAs consistent with optimal image quality.
Digital Imaging Considerations.
Post-processing evaluation of exposure index:
Once the image is available for viewing, the image will be critiqued for positioning and exposure accuracy.
The tech must check the exposure index number to verify that the exposure factors used were in the correct range to ensure optimum quality with the least radiation to the patient.
Alternative modalities or procedures.
Conventional and computed tomography:
Conventional tomography used to be used for locating lesions found on chest films, but CT is frequently used for such purposes.
Alternative modalities or procedures.
Bronchography:
Radiologic procedure where contrast media was introduced into bronchial tree to rule out certain pathologies. Bronchography has ben replaced by different imaging procedures including CT.
Alternative modalities or procedures
Sonography:
May be used to detect pleural effusion.
May be used guidance when inserting a needle to aspirate fluid.
Alternative modalities or procedures
Echocardiogram
ultrasound of the heart.
Alternative modalities or procedures
Nuclear Medicine
- With the use of radionuclides can be used to evaluate and diagnose pulmonary diffusion condition or pulmonary emboli.
- Pulmonary emoboli- a suddenblocakge of an artery of the lung.
Alternative modalities or procedures
MRI
Used to evaluate and diagnose such pathologies as congenital heart disorders, graft patency, cardia tumors, thrombi, pericardial masses, and evaluation of aortic dissection and aneurysms.
Basic projections vs. special projections
Basic are standard, sometimes called “routine.” They are those projections taken as extra or additional procedures to demonstrate certain pathologic conditions or specific body parts, or when the patient is not able to cooperate fully.
Chest radiography
Basic images:
PA and lateral.
Chest radiography
Special images:
AP supine or semierect lateral decubitus AP lordotic Anterior oblique Posterior oblique
PA projection.
Pathology demonstrated:
Pleural effusions
Pneumothorax
Ateclectasis
PA projection
Technical factors:
14x17 IR Placed lengthwise or crosswise Brid 110-125 kVp Sheild radiosensitive tissue outside region of interest.
PA projection
Shielding:
Place a shield between X-ray tube and patient’s pelvis. References also suggest another shield placed between patient gonads and the IR for back scatter protection.
PA Projection
Patient position
Erect
weight evenly distributed
chin elevated
hands on lower hips, palms out
roll shoulders forward again IR to allow scapulae to move laterally
depress shoulders to move clavicle below apices
adjust shoulders so they are in same transverse plane
PA projection: part position
Center MSP of body to midline of the IR.
Ensure no rotation: MSP perpendicular; MCP parallel to IR.
Adjust CR and IR as needed to level of T7 for average patients.
Top of IR will be about 1 and a half inches to 2 inches above relaxed shoulders.
PA Projection
Central Ray
Perpendicular to center of IR - centered to MSP at level of T7.
IR centered to CR.
Minimum SID of 72 inches.
PA Projection
Collimation:
On all four side to area of lungs.
Top border of illuminated field to level of vertebra prominens.
Lateral borders of illuminated field to skin margins.
