Radiology Flashcards
1
Q
What does Radiopaque mean?
A
not allowing the passage of x-rays (more white) - metal- shows up bright white
2
Q
What does Radiolucent mean?
A
allow the passage of x-rays (more black) - air- nothing there to stop the xrays
3
Q
Xrays are a fom of what?
A
radiation
4
Q
How would you describe an Xrays wavelength and what kind of energy is associated with that?
A
Short wavelength
High energy
The shorter the wavelength the greater the energy
5
Q
What are Xrays generated by?
A
an electrical source
6
Q
What do Xrays consist of?
A
waveform packets of energy called photons
7
Q
What is the amount of energy in an Xray measured in?
A
electron volts (KeV)
8
Q
What would you do if your image turned out to be all white?
A
If the image turned out all white then you would adjust the KeV- too much energy
9
Q
Where do Xrays leave the Xray tube?
A
through a small opening (collimator) that regulates the size of the beam
10
Q
Where is the xray beamed at?
A
the part of the body to be imaged
11
Q
Where is the film or screen placed at in relation to the patient?
A
The film or screen is placed behind the patient
12
Q
What happens when the Xrays pass through human tissue?
A
The x-radiation is absorbed and attenuated (weakened), or even blocked as it passes through the different tissues
13
Q
What is attenuation?
A
The greater the density of the tissues the greater the absorption of the X-rays
14
Q
What is the most common diagnostoc Xray format?
A
film or digital
15
Q
Is contrast used in Xray?
A
no
16
Q
What are some factors that affect image quality?
5
A
- Motion
- Thickness of the body part - harder to xray
- Scatter (intensity of the x-ray beam)- can scale it down for smaller space (finger)
- Magnification (distance the body part is away from the film vs. x-ray beam)
- Distortion (when the image is not lined up with the film)- spine isnt straight so image is distorted
17
Q
What kind of people are harder to Xray?
3
A
Obese people
Parkinsons
Kids
18
Q
In an AP Xray where is the person situated compared to the film?
And how would you describe the quality of the film?
A
- Back is to the Xray
- Heart is further from the film
- Longer distance from heart to film = worse quality and more magnified
19
Q
In a PA xray where is the persoon situated compared to the film?
And how would you describe the quality of the film?
A
- Front is to the Xray
- Heart is closer to the film
- Smaller distance from the heart to film= Better quality and less magnified
20
Q
Why do we do AP xrays at all then?
A
in ER because they cant stand.
21
Q
What is fluoroscopy?
A
Moving/real time x-rays
Images can be recorded and played back
Images can be captured as a still picture
An XRAY movie!
22
Q
Examples of fluoroscopy?
4
A
GI studies like barium swallow;
angiography;
draining abscesses; intraoperative feedback
23
Q
What can we diagnose with a barium swallow?
7
A
- Cancers of the head, neck and pharynx
- Tumors
- Hiatal hernia
- Structural problems
- Muscle disorders
- Esophageal Strictures
- GERD
24
Q
Complications in barium swallows?
A
barium might not go down the esophagus. it aspirated into their lungs. could cause pneumonitis
25
What does an upper GI series include?
| 3
X-ray examination of the upper GI tract, esophagus, stomach and duodenum
26
What is an Upper GI series used to diagnose?
What specifically?9
Used to diagnose structural or functional abnormalities of the upper GI tract
1. Ulcers (gastric or duodenal) - normally you scope them but sometimes you do upper gi for other things and find an ulcer
2. GERD,
3. inflammation,
4. tumors
5. Polyps,
6. strictures,
7. diverticula
8. Dysphagia
9. Motility disorders
27
What does CT stand for?
Computer Assisted Tomography
28
What are CTs best for?
Useful for the evaluation of soft tissue and bone as compared to plain x-rays
BEST AT BONE
29
What is MRI best as imaging?
soft tissue
30
What is a CT?
Medical imaging technique that uses x-rays to create pictures of cross-sections of the body
Thin XRAY beam rotates around the body making 3D images
31
How would you describe the amounts of radation with CT?
Large amounts
32
Why couldnt someone have a CT?
Iodine allergies (anaphelactic)
33
Describe the original CT scan?
took longer
| Each "slice" that we took was independant and there was significantly more radiation
34
What was the distance between slices in the old CTs?
Distance between slices was 3mm, 5mm, 10 mm
35
What kind of CTs do we use now?
Spiral CTs or continuous CTs
36
What different kind of CT techniques/types are there?
| 5
1. Bone windows
2. Lung windows
3. Venous phase acquisition
4. IV contrast
5. Oral contrast
37
What parts of the body can we image using CTs?
Can image any body part (head, chest, lungs, heart, abdomen, pelvis, extremities)
38
How would we perform a CT angiography?
IV contrast
39
Where is IV contrast cleared through?
The kidneys
40
What kind of complications can be seen with IV contrast?
Iodinated (Iodine allergies)
| Cannot use for renal failure patients
41
What is Oral Contrast make of?
Barium
| Water soluble iodinated contrast
42
Cannot Use CTs for any kind of patient with renal failure
statement
43
What is an MRI?
Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body.
44
What is an MRI good for imaging?
imaging soft tissue such as the brain, spinal cord, muscles, tendons, ligaments, etc.
45
Benefits of MRIs?
| 3
1. No radiation
2. Contrast is gadolinium based not iodine based
3. Side Effects and allergic reactions are rare
46
Why would people with a history of welding need to be screened before getting an MRI? Or any metal tranplants, pacemaker etc?
Metal pieces in the eye would be activated by the magnet in MRI
47
How would MRIs affect the kidneys?
Very well tolerated but can cause worsening renal failure in already impaired kidneys
48
How does the magnet work in MRIs?
LARGE magnet that aligns our protons through the delivery of radiofrequency pulse waves
49
In a T1 MRI what substances are darker?
CSF
| Ca
50
In a T2 MRI what substances are darker?
Bone and fat
| White matter
51
What lookd grey in T1 and T2 MRIs?
grey matter
52
In a T1 MRI what substances are lighter?
| 3
Fat
Bone marrow
Melanin
53
IN a T2 MRI what substances are lighter?
Brain Edema
| Water
54
What happens in a ultrasound?
The ultrasound transducer converts electrical energy to sound energy which is transmitted to the patients tissue
The transducer then becomes a receiver that detects sound echoes reflected from the tissues
55
Why are there different probs used in different ultrasounds?
They make different kinds of arrays
| These arrays are used for different shapes/images of the body
56
Benefits of ultrasound?
| 3
Image virtually any body part
No radiation
Noninvasive
57
When would you use contrast in an Ultrasound?
Cardiac imaging to enhance cardiac structures
- Agitated saline
- Lipid suspension
58
Downsides to ultrasound?
| 2 examples
Technology limited by fat and air
- Very hard to use with people who are obese
- COPD patients will have excess air in their lungs/expanded lungs
59
What does hyperechoic mean?
increased amplitude of ultrasound waves returned. Typical of bone and dense tumor tissue. “white spots”
60
What does hypoechoic mean?
decreased amplitude of ultrasound waves returned. Typical of air or fluid or tissue that is less dense then what surrounds it “dark spots”
61
What does a dark, prominant shadow mean in an ultrasound?
object is really dense (gallbladder)
62
What is a doppler unltrasound used for?
Uses reflected sound waves to evaluate blood as it flows through a blood vessel
63
What can a doppler ultrasound determine?
determine stenosis and plaque build up, narrowing, or a clot
64
How is flow measured in a doppler ultrasound?
velocities
65
What does nuclear medicine usually show in the system being investigated?
Primarily shows physiologic function of the system being investigated
More organ specific
66
Describe how nuclear medicine usually works?
| 2
1. Uses a radiotracer (isotope) that is injected into a vein, ingested or inhaled to image the organ being evaluated
2. The isotope emits gamma rays and this energy is imaged using a gamma camera
67
HOw do isotopes from nuclear medicine usually leave the body?
arent washed out they usually are degraded
68
What kind of studies of nuclear medicine are there
| 10
```
Bone scan
PET scan
Myocardial perfusion scan
MUGA scan
Cardaic viability scan
Parathyroid scan
Thyroid scan
Hepatobiliary scan (HIDA) scan
VQ scan
Lymphoscintigraphy scan
```
69
What does a bone scan tell us?5
Who do we not bone scan?
(not for kids who are still growing: is it inflammation or growth)
Eval bone related pathology: bone pain, stress fractures, bone lesions, infection, bone cancer
70
What does a PET scan tell us?
Eval for cancer metastatsis. Determines cancer activity
71
What does a myocardial perfusion scan tell us?
Eval for cardiac ischemia also can get cardiac function in most cases- evaluating blood flow to the heart
72
What does a MUGA scan tell us?
Cardiac function- ejection fraction of heart. cancer patients have it before and after procedure to check heart
73
What does a Cardiac viability scan tell us?
Specialized test to evaluate for hibernating myocardium to determine if revascularization would be beneficial
74
What does a parathyroid scan tell us?
Evaluation for adenomas
75
What does a thyroid scan tell us?
Eval of nodules and hyperthyroidism
76
What does a Hepatobiliary scan (HIDA) scan tell us?
Eval for gallbladder disease
77
What does a VQ scan (ventilation/perfusion)
| tell us?
Eval for pulmonary embolus
78
What does a Lymphoscintigraphy
| tell us?
Eval of the lymph system for disease (lymphoma, lymphedema)
79
Does a myocardial perfusion scan tell us anything about blood vessels?
NO
| Only shows perfusion to the distinct areas of the heart(not the same as an angiogram)
80
Why do we do a red blood cell study and how do we do it?
To evaluate for occult bleeding when unable to determine source of bleeding by endoscopy
Red cells are tagged with radioisotopes
81
Why would we do a VQ scan instead of a CT?
terrible kidney function so no contrast and some might have contrast allergies
82
What are the black spots in a bone scan?
where patient has bone infection or where cancer is
83
HOw would we know to do a bone scan?
| 2
you probably have been treating them for cellulitis first so it looks bad but is not getting any better
or the pain is out of proportion to what it looks like
*then order BS
84
What does PET stand for?
Positron emission tomography (PET)
85
What is a PET SCAN?
Whats it most commonly used for?
is a nuclear medical imaging technique that produces a three-dimensional image or picture of functional processes in the body.
Evaluate for cancer metastasis
86
Describe the process of a PET scan
What is it often used to evaluate?
1. Radioactive isotope injected
2. Gamma ray technology
3. Pictured here is a tumor that is “hot” or more metabolically active then the surrounding tissue
Used to evaluate remission
87
What do we use an angiography for?
Used for imaging blood vessels
88
What does a traditional angiography use for imaging?
fluoroscopy
89
Angiographies can be obtained how?
| 3
fluoroscopy
MRI
CT
90
What kind of contrast is needed for imaging?
IV contrast
91
Angiograpies need what kind of equipment?
procedure, sterile technique, draping as if it was a surgery
have to be NPO, schedueled ahead of time
invasive procedure/big deal!!
Basically just know that it is a big deal. Complex/Invasive
92
What are the downsides to angiographies?
| 5
1. Invasive with inherent risks of thrombosis, dissection, bleeding
2. Sedation necessary
3. IV contrast necessary
4. Careful in renal failure
5. Careful in history of iodine allergy
93
If there isnt any contrast going to vasculature what does that indicate?
stenosis or clot
94
What types of procedures is IV contrast used in?
| 3
plain x-rays, fluoroscopy, and CT scans
95
What is the path for IV contrast?
Spread through the blood stream, excreted by glomerular filtration in the kidneys
96
Adverse affects of IV contrast?
| 5
1. 5-10% : true allergic reaction
2. Nausea, vomitng
3. Hives (urticaria)
4. Feeling of warmth with injection
5. Pain at site of injection
97
When do the most life threatening reactions to IV contrast present themselves?
during the 1st 20 minutes after injection
98
What happens symptoms of an anaphylatic reaction of IV contrast?
8
2. Severe bronchospasm or laryngeal edema
3. Loss of consciousness
4. Seizures
5. Cardiac arrest
6. Complete cardiac collapse
7. Cardiotoxicity
8. Hypotension, dysrhythmias, precipitation of congestive heart failure
99
Why does contrast so negatively affect kidney function?
Because its excreted through the kidneys and with low kidney function the contrast will be around a lot longer. The contast will then produce acidic environment and further decrease kidney function
100
When does acute renal failure occur within 48 hours of contrast administration?
What levels rise in the first 48 hours? (what would we test for?)
How do we define contrast induced nephropathy quantitatively?
When do serum levels return to baseline?
Renal fucntion peaks at 48 hours of injection of the contrast
```
Serum Creatinine (and BUN) levels rise in first 24 hours and should peak at 48 to 72 hours
Defined as > 25% increase in serum creatinine within 5 days
Usually return to baseline by 10-14 days
```
101
How do we prevent contrast induced nephrotherapy?
| 5
1. Many radiologists require serum creatinine and BUN levels drawn within 1 week of any procedure that will require IV contrast
2. Patients must be well-hydrated
3. Encourage your patients to drink several liters of fluid over the 12-24 hours before and after an IV contrast administration.
4. IDENTIFY your high risk patients to the RADIOLOGY Team
5. Discuss alternative studies as always: the benefits of the test should outweigh the risks
102
What type of medication do we hold for IV contrast and why?
Metformin
May precipitate FATAL LACTIC ACIDOSIS in the presence of renal impairment
Hold two days before and after
103
What should we give patients that have had a mild allergic reaction before in IV contrast?
prednisone and benedryl
104
What kind of contrasts can be used for GI?
| 4
1. Barium Sulfate
2. Water Soluble oral contrast (Gastrografin)
3. Air
4. Carbon Dioxide (can also be used for vascular studies but very rarely used)
105
When would we use a water soluable contrast?
If there is any hint of perforation
106
Why could barium cause peritonitis?
Leakage of barium out a GI perforation into peritoneum acts as foreign body reaction
107
Side effects of barium?
What would you instruct a patient to do after a barium swallow?
Severe constipation, obstipation, bowel obstruction
laxative
108
What should you use (contrast) when a bowel obstruction is suspected?
WATER SOLUBLE IODINATED CONTRAST MEDIA
109
What happens if a WATER SOLUBLE IODINATED CONTRAST MEDIA
| is aspirated?
chemical pneumonitis
110
What is a side effect of WATER SOLUBLE IODINATED CONTRAST MEDIA and who is at risk?
Can cause significant diarrhea due to osmotic loading in bowel
- Risk for elderly
- Risk for neonates
111
What imaging tests have very high radation exposure?
| 4
Nuclear cardiac perfusion scan (4070)
CT is next (700)
Bone scan and Upper GI are next but lower
112
What imaging tests have the lowest radiation?
| 3
Xrays
Ultrasounds and MRIs have zero
