Airway Management II: Lecture 5 - Radiology of the Airway Flashcards
(73 cards)
What is the characteristic finding on x-ray seen in conditions such as Croup?
Steeple sign
The steeple sign indicates narrowing of the upper airway, commonly seen in croup.
What is the characteristic finding on x-ray seen in conditions such as Epiglottitis?
Thumb sign
The thumb sign indicates swelling of the epiglottis, which can obstruct the airway.
What are X-rays?
Photons formed within an x-ray tube (cathode-ray tube) that pass through objects and are attenuated by various tissues.
What is the most common type of X-ray?
Portable X-ray (Anterior-posterior chest film (AP))
Portable X-rays include anterior-posterior chest films (AP).
What imaging technique is used for real-time, live imaging during surgery?
Fluoroscopy… mostly used to detect location of tools and implants
Fluoroscopy helps in detecting the location of surgical tools and implants.
What are the most important plain films for anesthesia?
C-spine, chest, neck plain films
C-spine = Most common are lateral, anteroposterior (AP), open-mouth odontoid, oblique, and pillar views
These include lateral, anteroposterior (AP), open-mouth odontoid, oblique, and pillar views.
Who discovered X-rays and won the first Nobel Prize in Physics?
Wilhelm Conrad Roentgen
1845–1923
Discovered X rays in 1895 while he was experimenting with electricity
Because he did not really understand what these rays were, he called them X rays because in mathematics X stands for the unknown
His discovery led him to win the first Nobel Prize in Physics in 1901
Roentgen’s discovery in 1895 revolutionized medical imaging.
What is the unit of radiation exposure that produces a specific amount of ionization in 1 cc of air at standard conditions?
Roentgen
The Roentgen (R) is a measuring unit of radiation exposure.
The amount of radiation which exits from the tube at certain technique factor settings is measured in Roentgens (R).
The Roentgen is a measure of exposure to ionizing radiation.
What unit represents the actual dose of radiation absorbed by the part being radiographed?
Rad = unit of absorbed energy
This is the most functional term for our purposes because it represents the actual dose, or how much radiation is actually absorbed by the part being radiographed.
the amount of radiation absorbed by the skin would be greater than the amount absorbed by the thyroid, or the bone marrow, or the gonads.
For this reason, a measurement in rads must be accompanied by a specification of the body part in question, where the dose is being measured, for it to have meaning and in order for it to be used as a comparison to other dose measurements.
The Rad measures the absorbed dose of radiation in tissue.
What unit of exposure takes into account the relative biological effects of varying types of ionizing radiation?
Rem
It stands for Roentgen equivalent in man (mammal), and it is the unit of exposure which takes into account the relative biologic effects of varying types of ionizing radiation.
The rem provides a way to measure and compare other forms of ionizing radiation (such as alpha, beta, and gamma rays) which are also capable of producing ionization in tissue.
The Rem is used to measure exposure to ionizing radiation with biological effects considered.
What does ‘rem’ measure?
A way to measure and compare other forms of ionizing radiation capable of producing ionization in tissue.
What unit of x-ray exposure is abbreviated as ‘R’?
Unit of x-ray exposure.
What unit of x-ray absorbed by tissue is abbreviated as ‘r’?
Unit of x-ray absorbed by tissue, must state where.
Rem?
Exposure equivalent - other forms of ionizing radiation
What is the appearance of air on an x-ray film?
Little interaction with x-ray beam/passes easily, appears black on film.
What is the appearance of fat on an x-ray film?
Middle amounts of interaction with x-ray beam, appears grayish on film.
What is the appearance of fluid/soft tissue on an x-ray film?
Middle amounts of interaction with x-ray beam, appears grayish on film.
What is the appearance of bone on an x-ray film?
Large amount of interaction with x-ray beam/beam doesn’t pass easily, appears white on film.
What is the appearance of metal on an x-ray film?
Large amount of interaction with x-ray beam/beam doesn’t pass easily, appears white on film.
What does a high hemidiaphragm indicate?
Decreased lung volume
A high hemidiaphragm can suggest conditions like atelectasis.
Pertinent Findings for Anesthesia
Level of Diaphragm
Lung Aeration
Mediastinum and Heart
Tracheobronchial Tree
Endotracheal tube positioning
NG tube positioning
Level of Diaphragm
High hemidiaphragm implies ↓ lung volume
Phrenic n. paralysis
Conditions causing chx pain splinting
Extrapulmonic processes
Enlarged spleen, liver, pancreatitis, or subphrenic abscess
What should a well-expanded lung appear as on an x-ray?
Radiolucent with lung markings.
Interstitium consisting of septa, and arterial, venous, and
lymphatic vessels
Normally lungs are more lucent at the apex
CHF or pulm. venous Htn pattern is reversed w/
engorgement of pulm veins in the upper lung zones
If lungs appear more opaque
Pleural effusion, pulm. edema, pneumonia, lung mass, lung collapse or atelectasis, lung infarct or contusion, and metastatic dz
PICTURE: Normal vs Pulmonary HTN
What structures lie centrally in the chest?
Mediastinum and Heart
Great vessels and heart centrally located on AP
view of mediastinum
Contains hila, tracheobronchial tree, heart and great vessels, lymph nodes, esophagus, and thymus
The mediastinum contains the heart and great vessels.
