Clinical Anatomy 1 Nomenclature/terminology Flashcards
What are three forms of ionizing radiation?
- Plain X-ray
- Computed tomography (CT scan)
- Nuclear medicine imaging
What are two forms of non-ionizing radiation?
- Ultrasound
2. Magnetic resonance imaging (MRI)
What is a non-sectional image?
Conventional or plain X-rays
What are 5 Sectional images?
- Computed tomography (CT scan)
- Positron emission tomography (PET)
- Single photon emission tomography (SPECT)
- Magnetic resonance imaging (MRI)
- Ultrasound
What are 2 Nuclear Medicine technologies?
- Positron emission tomography (PET)
2. Single photon emission tomography (SPECT)
Who discovered X-rays and when?
- Discovered in 1895
- Wilhelm Conrad Roentgen (German physicist)
When was x-rays first used in medicine?
First used to image human tissue in 1896
How do x-rays work? (2 steps)
- X-ray machine sends one radiation beam that passes through the body and is detected on photographic film or detector plate placed opposite the X-ray source
- X-rays are absorbed or scattered to varying degrees by different tissues in the body
* x-rays are absorbed depending on the density of the tissue. This is the basis for radiographic image formation and contrast.
What are 2 standard projection for chest x-ray?
- Posterior Projection
2. Lateral Projection
What are radiographs?
- Also known as x-rays
- Is a superimposition of shadows of many different structures
- Are photographic negative
Why are there shadows in x-rays?
Shadows are created due to air
What are images in x-rays?
Shadows of more dense and less dense tissues of a part of the body
What are denser tissues in x-rays?
- They absorb more x-rays and cast a white shadow known as Radiodense or radiopaque
- Compact Bone is more dense than spongy bone
- This is seen as increased radiodensity in an x-ray
What are less dense tissue in x-rays?
- Allow most of the x-ray to pass through creating a grey/darker shadow known as Radiolucent
- Spongy bone is less dense due to the amount of cavities.
- This is seen as increased radiolucency
What is Radiodense?
- Denser tissue in an x-ray that absorbs x-rays
- Radiopaque
What is Radiopaque
- Denser tissue in an x-ray that absorbs x-rays
- Radiodense
What is Radiolucent?
- Less dense tissue in an x-ray
- Radiolucency are shadows that don’t absorb the light
What is Density interface?
Refers to the anatomical boundary between structures of different densities that about one another
-The boundary from the heart and lungs.
What are 3 kinds of medical images generated by x-ray radiation?
- Conventional (plain) X-ray imaging
- Contrast X-ray imaging
- Fluoroscopy
How are plain x-ray images sharper?
Structures closer to the film cassette are sharper
In a lateral view of an chest x-ray where should the film cassette be placed?
Film cassette placed against the Left side because it is closer to the heart (sharper image).
What is Contrast x-ray imaging?
- Use contrast agent or dye to improve image contrast of structures that do not have inherent differences in radiographic density
- Used when two structures have similar density (ex. Density tissue of the esophagus and heart are similar)
What dye is used in blood vessels?
- Water-soluble iodine dyes
- Using dye in blood vessels in known as angiography
What is angiography?
- Using water-soluble iodine dye in the blood vessels
- Help to diagnose an obstruction, blockage,
narrowing (“stenosis”), aneurysm (ballooning)
of a blood vessel - Stenosis- the abnormal narrowing of a passage in the body
- Aneurysm- an excessive localized enlargement of an artery caused by a weakening of the artery wall
What is Stenosis?
The abnormal narrowing of a passage in the body
What is Aneurysm?
An excessive localized enlargement of an artery caused by a weakening of the artery wall. (ballooning of a blood vessel)
What dye is used for the urinary system?
Water-soluble iodine dyes
- Used to detect urinary tract obstructions
due to kidney stones or tumors, congenital
anomalities
What dye is used for the Gastrointestinal tract?
Barium sulphate
*Used for the detection of ulcers, diverticulum, hiatus hernia, esophagitis, tumors, polyps
What are 2 risks using contrast x-ray imaging?
- Allergic reaction
2. Small Bowel obstruction
Why are contrast x-rays less used/being replaced? (3 reasons)
Being replaced by techniques such as CT scan, MRI, and Ultrasound scanning because they all produce:
- Better-quality images
- Cause less discomfort
- Involve fewer risks to health
What is Fluoroscopy?
Study of moving body structures in real time imaging
- Allows for the observation of movement
- Commonly used to observe the gastrointestinal tract (Assists the physician in insertion of Gastrostomy tubes, intravenous cardiac insertion)
How does fluoroscopy work? (3)
- Controlled with a switch
- Strike a fluorescent plate coupled to and image intensifier and a TV camera
- Images are transmitted to a TV monitor
What is Computed Tomography (CT scan)?
Is an imaging technique that produces cross-sectional images or “slices” of an area of the body or of internal organs, blood vessels, bones, muscles, and joints.
How does CT scan work? (5)
- An X-ray beam source rotate continuously around the longitudinal axis of the patient’s body as the patient platform glides
- A fan-shaped X-ray beam passes through a given region of the patient’s body
- X-rays are picked up by digital X-ray detectors on the opposite side of the X-ray source
- X-ray data collected from multiple angles are sent to a computer that creates separated cross-sectional images of a body area
- Cross-sectional images can either be displayed individually or stacked together by the computer to generate a 3D image on a monitor
Computed Tomography Images?
More detailed than conventional (plain) X-ray
What is X-ray beam attenuation?
- Radiographic contrast of images results from X-ray beam attenuation
* Is the reduction in intensity of an x-ray beam
What is attenuation in CT scan?
Loss of power of X-ray beam as it travels through tissues
What is higher attenuation in CT scans?
Higher attenuation of X-ray beam create white to light gray shadows
What is Lower attenuation in CT scans?
Lower attenuation of X-ray beam create gray to black shadows
What is the order of CT scan density from high to low?
7 images
- Barium
- Bone
- Muscle
- Liver/Kidney
- Water/ CSF
- Fat
- Air
What are the 12 Advantages of using a Computed Tomography?
- Rapid
- Affordable
- Availability
- Detailed images of any part of the body
- Diagnoses and evaluation of the extent of tumor, masses, nodules
- Evaluation of size, shape and contour of organs
- Evaluation of joint dislocation
- Evaluation of fracture of curved bones
- Shadows do not overlap
- Location and extent of emphysematous bullae (damaged alveoli that distend to form exceptionally large air spaces), bronchiectasis(damage to the airways)
- To determine pattern of calcification of pulmonary nodules
- Detection of intracranial abnormalities
What 2 disadvantage to Computed Tomography?
- Claustrophobia
2. Contraindicated in pregnancy
What is Molecular imaging?
Medical imaging that allows to visualize and to measure the biological processes taking place in the living subject at cellular and molecular levels and can detect and treat disease in its earliest stages
What is Nuclear medicine? (3)
- Involves the administration of radiopharmaceuticals (radioactive material bound to a drug that work as a tracer) that target specific organs or cellular receptors and bind to them selectively
- Radiopharmaceuticals are injected, swallowed or inhaled depending on the organ under investigation to diagnose a disease or to treat it
- Shows the physiological activity of the tissue or organ being investigated
What are 2 types of Nuclear medicine?
- Positron emission tomography (PET)
2. Single photon emission tomography (SPECT)
How does PET and SPECT work? (2)
- The radioactive agent emits gamma rays measured by a gamma camera in the scanner which then converts the rays to electronic signals
- Electronic signals are send to a computer which creates 3D images
What makes PET & SPECT different from other methods?
The radiation emitted from inside the body is detected rather than being applied externally, as with an X-ray procedure
What is Positron emission tomography (PET)? (4)
- Measures metabolic activity of cells
- Frequently uses 18F-fluorodeoxyglucose, FDG, an analogue of glucose as a radiotracer
- The drug (tracer) is absorbed by the organ tissues
- Three-dimensional images show how the FDG is distributed in the area of the body providing important information on the cellular activity
*Nuclear Medicine
What is Single photon emission tomography (SPECT)?
The tracer stays in the blood stream rather than being absorbed by surrounding tissues, thereby limiting the images to areas where blood flows
What radioisotopes tracers are used in SPECT? (5 types)
- Iodine-123
- Technetium-99m
- Xenon-133
- Thallium-201
- Fluorine-18
What radioisotope tracer is used in PET?
18F-fluorodeoxyglucose, FDG
Why is PET used?
- Used to detect and evaluate cancerous tumors (Cancerous tumors are EXTREMELY DIFFICULT TO DETECT)
- Useful in diagnosing neurological conditions and cardiovascular disease
What is Glucose consumption in PET?
- Glucose is higher in cancer cells than normal cells
2. Increase in the seizure focus in epilepsy
Why is SPECT used? (2)
- Used in cardiology to provide information about blood flow through the heart muscle that can be used to diagnose heart disease
- Useful in diagnosing blood deprived (ischemic) areas of brain following a stroke, stress fractures, infection, and certain types of tumors
*Tracer stays in the blood; NOT absorbed
What are Hot Spots in SPECT?
Are areas of increased concentration of the tracer that indicates increased physiological activity that may occur as a result of disease or injury
How does MRI work? (5)
- Uses strong magnetic fields created by the MRI machine around the patient to align spinning atomic nuclei (usually hydrogen protons) within body tissues
- Then uses a radio signal to disturb the axis of rotation of these nuclei and observes the radio frequency signal generated as the nuclei return to their baseline states
- The spin of the proton of Hydrogen atoms produce a signal at a characteristic frequency that form the basis of MRI
- The emitted radio frequency signal varies from one to another tissue depending on proton environment
What are the 4 advantages of using MRI?
- No ionizing radiations
- No invasive
- Production of images from any desired angle (axial, coronal, sagittal, oblique planes) and at any level
- Give the best soft tissue contrast of all imaging modalities by providing more detailed anatomical images
What are the 8 disadvantages of using MRI?
- High cost
- Availability
- Time
- Claustrophobia
- Static
- No good identification of cortical bone lesions
- Ferromagnetic metals (Risk of complications related to pacemakers, heart valve replaced, aneurysm clips, metallic ear implant)
- Contraindicated in pregnancy
How does Ultrasound work? (4)
- Uses the same principle as sonar (Sound Navigation and Ranging)
- Bouncing sound waves off objects in the body to visualize soft tissue structures in the body in real time.
- High frequency sound waves are transmitted from a transducer into the body.
- Reflected sound waves (“echoes”) are picked up by the transducer, transformed into electrical signals, send to a computer, and processed to create the image that is displayed on a TV monitor.
How does Ultrasound-Reflected sound waves (echoes) work?
- Bounce back from boundaries between tissue of different densities (different echogenicity) like Water and fat; Fat and muscle
- Strength of the reflected sound wave depends on the difference in tissue density between adjacent structures
- The greater the difference in tissue density between two adjacent tissues the more reflective will be their boundary
What are Very reflective interfaces in ultrasound?(2)
- Bone - soft tissue
2. Air - soft tissue
What are Poorly reflective interfaces in ultrasound?
Soft tissue interfaces (heart and the esophagus)
What is Anechoic (ultrasound)?
- No echoes or sound wave reflection
- Appear black
- Ex: Fluid, Amniotic fluid, simple cysts, vessels, ascites
What is Hypoechoic (ultrasound)?
- Dark on the film with some low grade echoes
2. Ex: Organs, tumors, nodes
What is Hyperechoic (ultrasound)?
- Bright on the film with significant echoes
2. Ex: Fat & bone
What are 8 Ultrasound Applications?
- Determination of cystic from solid masses (kidney, breast, liver)
- Evaluation of size and shape of organs (abdominal, pelvic, thyroid)
- Detection of Renal stones and gall stone
- Monitor fetal development and detection of congenital anomaly
- Early diagnosis of ectopic pregnancies and pelvic conditions
- Useful in early diagnosis of pregnancy in obese patients
- Echocardiography
- Doppler
What is echocardiography?
Evaluation of heart function (heart chamber size, wall motion, valve movements, effectiveness of the heart pumping ability)
*Type of ultrasound
What is Doppler ultrasound?
Quantitative measurement of blood flow in the neck and limbs
What are the 6 Advantages of ultrasound?
- Noninvasive
- inexpensive
- Quick
- Portable
- Does not utilize ionizing radiations
- No confirmed adverse biological effects on patients or instrument operators
What are the 2 disadvantages of using ultrasound?
- Operator dependence (Quality of the images is highly dependent on the skill of the person performing the exam)
- Unable to image through air (lungs and bowel) or bone
What is the other name for Aponeurosis musculi bicipitis brachii?
Bicipital aponeurosis
What is Supine position?
Body lying down on the back with the face pointing upward
- Also known as dorsal recumbent
What is Prone position?
Body lying down on the abdomen and face directed downward
*Also known as ventral recumbent
What is Left/Right lateral recumbent position?
Lying down on left or right side
What are 4 Planes and Sections?
- Median Plane
- Sagittal plane
- Coronal plane
- Horizontal (transverse) plane
What are the 3 names for position of structures?
- Superficial
- Intermediate
- Deep
What is Ipsilateral?
Something occurring on the same side of the body or moving body parts to the side of the body where its is located (right upper limb & right lower limb)
What is Contralateral?
Something occurring on the opposite side of the body or moving body parts to the side of the body opposite to its location
What is Ipsilateral rotation?
Rotation of the trunk to the right; Right internal abdominal oblique muscle rotates the trunk to the right.
What is Contralateral rotation?
Left external abdominal oblique muscle rotates the trunk to the right.
