Lecture 7 - Final Flashcards
1
Q
How do you know if it’s adequate penetration
A
Anatomic silhouettes are visible. The film appears grey around the patient and you can see your fingers behind it.
2
Q
What do you change if the X-ray has good penetration but lacks the blackness
A
Increase mas x2
3
Q
What do you do if the outlines are not visible in an X-ray
A
Increase KVP by 10%
4
Q
What are the two questions to ask yourself if a X-ray is good
A
Is the film too light or too dark?
Is there proper penetration
5
Q
What are the qualities of a quality radiograph
A
Adequate penetration, sufficient density, good scale of contrast.
6
Q
What type of contrast do you want for soft tissue
A
Low contrast
7
Q
What type of contrast do you want for bone
A
High contrast
8
Q
What do radiopaque areas appear
A
White
9
Q
What color are radiolucent areas
A
Black
10
Q
Describe a positive contrast agent
A
Absorb more X-rays than soft tissue or bone. Contains element with a high density
11
Q
Describe negative contrast agents
A
Do not absorb X-rays. Appear black
12
Q
What are some advantages to barium sulfate as a positive contrast media
A
Insoluable and not diluted by gastric secretions ➡️ ideal for gi studies
Inexpensive
13
Q
What is the disadvantage of barium sulfate
A
The body cannot eliminate it since it is insoluable so if there is GI perforation it will not be absorbed and can cause irritations and cause risk of peritonitis reactions.
Can take 3 hrs or more to travel from stomach to colon.
14
Q
When can you not use barium sulfate
A
When there is a GI perforation
15
Q
What are organic iodides
A
Positive contrast medium Opaque Easily injected Well tolerated Water soluable: kidneys CAN BE EITHER IONIC OR NONIONIC
16
Q
Why would you use a PO formulation of a water soluable organic ionic iodide
A
For contrast studies of GI tract when GI tract perforation is suspected
17
Q
Why would you use an IV formulation of water soluable organic ionic iodides
A
To inject into a hollow organ such as bladder or an IV.
18
Q
Why isn’t iv formulation of water soluable organic ionic iodides used for myelography
A
Because it is irritating to the brain and the spinal cord
19
Q
What does rapid large IV bolus of water soluble organic ionic iodides cause
A
Vomiting and decreased blood pressure. Give a slow bolus
20
Q
What are water soluble organic non-ionic iodides used for
A
Myelography since it costs a lot of money
21
Q
What is myelography
A
To be injected into the sub arachnoid space the compartment within the spinal column which contains the cerebral spinal fluid
22
Q
What can be used as a negative contrast media with gas
A
Air, O2, N2, N2O, CO2
23
Q
Why must you not over inflate the organs when doing a negative contrast media with gas
A
Ulcerative lesions that causes the organ to rupture and cause an air embolism
24
Q
What are the negative and positive components to a double contrast procedure
A
Negative: air
Positive: water soluble organic ionic iodide
25
With what organs would you do a double contrast procedure
The urinary bladder, the stomach, the colon
26
How do you perform a double contrast procedure
Inject the negative contrast medium first such as the air.
27
Why do inject the negative contrast medium first in double contrast procedures
Can cause air bubbles to form and misinterpretation
28
How do you introduce contrast media
Oral administration or orogastric tube to prevent aspiration
29
Why are radiographs taken at intervals during contrast studies of the digestive system
Changes in morphology, rate of gastric emptying, small bowel transit time.
30
What are the warnings in contrast studies
Aspiration pneumonia, if you suspect perforation use an organic ionic iodide
31
How long should the patient be fasted before a contrast study
12 to 24 hours fasted
32
Do you use an enema in the contrast study
You may or may not use it depending.
33
Do use anesthetic in a contrast media
No because it alters gastric motility
34
Why is atropine or glycopyrrolate contra indicated when you're doing contrast studies
It's an anti-cholinergic drug that increases heart rate and decreases saliva it also relaxes the smooth muscle so it slows down gastric motility
35
Which anesthetic is okay for dogs in contrast studies
Ace promazine. Minimal facts on gastric motility in the dog. significantly shortened the transit time for cats. If gastric motility is a concern do not use Acepromazine in the cat.
36
What sedative is okay to use in a cat for contrast studies instead of Acepromazine
Ketamine
37
Why do you do a esophgography
To evaluate oesophageal function and structural alterations.
38
Why would you do a esophagography
Regurgitation of undigested food, acute gagging, dysphasia
39
Describe the contrast medium in an esophgography
Positive contrast medium. Barium sulfate paste mixed with canned food, if you suspect perforation use water soluble organic ionic iodide. Give it directly by the mouth with a syringe or an orogastric tube
40
What x-ray views are required when doing an esophagography
Lateral and VD of cervical and thoracic area including total length of esophagus
41
When do you do a ugi study
To evaluate stomach and small intestine, not the colon.
42
Why would you do a ugi
In the presence of reoccurring chronic vomiting. when suspecting obstruction by radiolucent foreign body into the stomach or small intestines. when suspecting wall lesions such as neoplasia
43
What is the contrast media used for the UGI study
Positive contrast agent barium sulfate 30% liquid diluted with one-to-one water. Water-soluble organic ionic iodide if suspected perforation
44
What is the quantity of contrast media to give for a UGI study
3 to 5 mL per pound
45
How do you give the contrast media for a UGI study
By Mouth or by an orogastric tube
46
What materials do you need to perform a UTI a study by mouth
Large dose syringe filled with the barium and administer directly into the mouth.
47
What materials are used for orogastric intubation for UTI study
Introduce an orange feeding tube into her stomach then connect the syringe filled with the appropriate quantity of barium
48
Perform the procedure for UTI study
Radiographs are made during transit of contrast to the stomach and small intestine until it reaches the colon. You need to do multiple x-rays at zero, 15, 30, 60, 90 +/- 180 min. Must do vd and lateral each time
49
Why do you do a Gastrography
To evaluate size shape and morphology of the stomach.
50
Why do you do a Gastrography
Acute or chronic vomiting, mass, foreign body, obstruction, cranial abdominal pain
51
Which contrast media do use for Gastrography
+ barium sulfate suspension 60%
+ water soluble in organic ionic iodide if suspected perforation
- air.
Double contrast agents
52
What is an LG I study used for
Introduction of a contrast media into the rectum, colon or caecum to study their position or Contour
53
Why do you do in LGI study
For diarrhea, tenesmus, blood, colitis, obstruction, neoplasia, to detect intussusceptions.
54
What is tenesmus
Forcing to pAss stools
55
What is intussuceptions
Intestines rolling inside itself
56
What is the contrast media used for a LGI study
+ barium sulfate 20% (60% diluted with saline)
| - or double contrasts.
57
How do you introduce the Contrast medium into the LGI study
By Foley catheter. Requires general anesthesia
58
What composes the upper urinary tract system
The kidneys and ureters
59
What composes the lower urinary tract system
Bladder and urethra
60
Why do we do a contrast study of the urinary tract
Indicated in patients with chronic problems such as chronic hematuria, protein urea, Crystalluria, polyuria, dysuria
61
What is a Cystography
Introduction of a contrast media into the bladder via the urinary catheter
62
Why would you do his cystography
Cystic calculi, neoplasia, bladder rupture, bladder wall anomaly
63
What does rapid large IV bolus of water soluble organic ionic iodides cause
Vomiting and decreased blood pressure. Give a slow bolus
64
What are water soluble organic non-ionic iodides used for
Myelography since it costs a lot of money
65
What is myelography
To be injected into the sub arachnoid space the compartment within the spinal column which contains the cerebral spinal fluid
66
What can be used as a negative contrast media with gas
Air, O2, N2, N2O, CO2
67
Why must you not over inflate the organs when doing a negative contrast media with gas
Ulcerative lesions that causes the organ to rupture and cause an air embolism
68
What are the negative and positive components to a double contrast procedure
Negative: air
Positive: water soluble organic ionic iodide
69
With what organs would you do a double contrast procedure
The urinary bladder, the stomach, the colon
70
How do you perform a double contrast procedure
Inject the negative contrast medium first such as the air.
71
Why do inject the negative contrast medium first in double contrast procedures
Can cause air bubbles to form and misinterpretation
72
How do you introduce contrast media
Oral administration or orogastric tube to prevent aspiration
73
Why are radiographs taken at intervals during contrast studies of the digestive system
Changes in morphology, rate of gastric emptying, small bowel transit time.
74
What are the warnings in contrast studies
Aspiration pneumonia, if you suspect perforation use an organic ionic iodide
75
How long should the patient be fasted before a contrast study
12 to 24 hours fasted
76
Do you use an enema in the contrast study
You may or may not use it depending.
77
Do use anesthetic in a contrast media
No because it alters gastric motility
78
Why is atropine or glycopyrrolate contra indicated when you're doing contrast studies
It's an anti-cholinergic drug that increases heart rate and decreases saliva it also relaxes the smooth muscle so it slows down gastric motility
79
Which anesthetic is okay for dogs in contrast studies
Ace promazine. Minimal facts on gastric motility in the dog. significantly shortened the transit time for cats. If gastric motility is a concern do not use Acepromazine in the cat.
80
What sedative is okay to use in a cat for contrast studies instead of Acepromazine
Ketamine
81
Why do you do a esophgography
To evaluate oesophageal function and structural alterations.
82
Why would you do a esophagography
Regurgitation of undigested food, acute gagging, dysphasia
83
Describe the contrast medium in an esophgography
Positive contrast medium. Barium sulfate paste mixed with canned food, if you suspect perforation use water soluble organic ionic iodide. Give it directly by the mouth with a syringe or an orogastric tube
84
What x-ray views are required when doing an esophagography
Lateral and VD of cervical and thoracic area including total length of esophagus
85
When do you do a ugi study
To evaluate stomach and small intestine, not the colon.
86
Why would you do a ugi
In the presence of reoccurring chronic vomiting. when suspecting obstruction by radiolucent foreign body into the stomach or small intestines. when suspecting wall lesions such as neoplasia
87
What is the contrast media used for the UGI study
Positive contrast agent barium sulfate 30% liquid diluted with one-to-one water. Water-soluble organic ionic iodide if suspected perforation
88
What is the quantity of contrast media to give for a UGI study
3 to 5 mL per pound
89
How do you give the contrast media for a UGI study
By Mouth or by an orogastric tube
90
What materials do you need to perform a UTI a study by mouth
Large dose syringe filled with the barium and administer directly into the mouth.
91
What materials are used for orogastric intubation for UTI study
Introduce an orange feeding tube into her stomach then connect the syringe filled with the appropriate quantity of barium
92
Perform the procedure for UTI study
Radiographs are made during transit of contrast to the stomach and small intestine until it reaches the colon. You need to do multiple x-rays at zero, 15, 30, 60, 90 +/- 180 min. Must do vd and lateral each time
93
Why do you do a Gastrography
To evaluate size shape and morphology of the stomach.
94
Why do you do a Gastrography
Acute or chronic vomiting, mass, foreign body, obstruction, cranial abdominal pain
95
Which contrast media do use for Gastrography
+ barium sulfate suspension 60%
+ water soluble in organic ionic iodide if suspected perforation
- air.
Double contrast agents
96
What is an LG I study used for
Introduction of a contrast media into the rectum, colon or caecum to study their position or Contour
97
Why do you do in LGI study
For diarrhea, tenesmus, blood, colitis, obstruction, neoplasia, to detect intussusceptions.
98
What is tenesmus
Forcing to pAss stools
99
What is intussuceptions
Intestines rolling inside itself
100
What is the contrast media used for a LGI study
+ barium sulfate 20% (60% diluted with saline)
| - or double contrasts.
101
How do you introduce the Contrast medium into the LGI study
By Foley catheter. Requires general anesthesia
102
What composes the upper urinary tract system
The kidneys and ureters
103
What composes the lower urinary tract system
Bladder and urethra
104
Why do we do a contrast study of the urinary tract
Indicated in patients with chronic problems such as chronic hematuria, protein urea, Crystalluria, polyuria, dysuria
105
What is a Cystography
Introduction of a contrast media into the bladder via the urinary catheter
106
Why would you do his cystography
Cystic calculi, neoplasia, bladder rupture, bladder wall anomaly
107
What is the positive contrast medium used in a cystography
Water soluable organic ionic iodide.
108
What is the negative contrast media used in a cystography
Air.
109
What is a urethrography
Filling the urethra with a contrast medium
110
Why would you do a urethrography
Calculus, to detect urethral trauma. Stricture, obstruction.
111
What is the positive contrast media used in a urethrography
Water soluable organic ionic iodide
112
What is the negative contrast medium use in a urethrography
Air
113
What is an excretory urography
Iv injection of a cm into venous blood gets filtered out and collected by kidneys.
114
Why do you do an excretory urography
To evaluate renal function and ureters. To see kidney structure and kidney capacity to concentrate and excrete urine
115
What is the contrast medium used in an excretory urography
Sterile water soluable iodinated contrast medium
116
What are 5 typical properties of an ideal contrast medium
Non irritating or toxic side effects.
| Accurate delineation of the organ. Persistence for sufficient time to take radiographs, total expulsion from body.
117
Why do you do a negative contrast studies
Show the location, size and wall thickness of the organ.
118
What is a positive contrast study
Best way of detecting a small defect in the wall of the organ as minor contrast leakage is easily seen
119
What is a double contrast study
Uses a small amount of positive contrast medium to coat the mucosal surface of a hollow organ such as the bladder. Followed by the distension with air.
120
What is cr
Computed radiography
121
What is computed radiography
Uses storage phosphor image plates that are exposed and then undergo a seperate image readout process. The image plate is contained in a cassette
122
What is Dr
Direct radiography
123
What is direct radiography
Convert X-ray into electrical charges more or less directly, enabling almost instantaneous readout. Uses no cassette.
124
What is a fluroscopy
Uses X-rays to obtain real time moving images
125
What is a cat scan
X-ray generating tube that makes a continuous circular movement around the patient. Mathematically reconstruct a cross sectional image of a body area
126
What is a mri
Magnetic resonance imaging. Uses magnets and radiowaves to make the image. No X-ray produced.
127
What is ultrasound used for
Displays the soft tissue textures and dynamics of some organs.
128
How are sound waves classified
By wavelength
Frequency
Velocity
129
What is a wavelength
Distance from one band of compression to the next. Have a shorter wavelength than audible sound.
130
What is the frequency defined as
Number of complete waveforms per unit of time
131
Describe the relationship between frequency and wavelength
Inversely proportional . As the frequency increases the wavelength decreases
132
Describe the sound waves used by an ultrasound
High frequency sound waves
133
What does an ultrasound transducter probe do
Produces the ultrasound beam. Produces low intensity, high frequency sound waves.
134
Describe how the ultrasound probe works
It has piezoelectric crystals. When an electrical current runs through the crystals they vibrate and produce sound waves. When they're stuck by the returning echoes the crystals convert the echoes to electrical energy
135
What type of energy is ultrasound based on
Reflected energy
136
What type of energy is radiology based on
Transmitted energy
137
What does echogenic mean
That most of the sound is reflected back to the transducter. Appears white on the screen.
138
What does anechoic mean
Describes the tissues that transmit the sound to the deeper tissues and reflecting none of the sound back to the transducter. The area appears black on the screen and they're usually an organs fluids
139
What does hypoechoic mean
Describes tissues that reflect less sound back to the transductor than the surrounding tissues. They appear darker than the surrounding tissues and have a low level of grey compared to adjacent tissues.
140
What is hyperechoic
Describes tissues that reflect more sound back than the surrounding tissues. Reflects very white echoes and causes acoustic shadowing
141
What is an example of a hypoechoic item
Hematoma
142
What is an example of a hyperechoic item
Air, bone, bladder stones etx.
143
What is isoechoic items
Items with the same echo texture as the surrounding tissues.
144
Why do we clip an animals hair for ultrasound
Interferes with image and decreases quality
145
Why do we use acoustic gel on the ultrasound probe
To increase contact surfaces
146
Why do you avoid barium or topical products with zinc when doing an ultrasound
Will interfere with sound transmission
147
If you're doing an abdominal ultrasound do you have to fast
Yes for 12hr to allow visualization of stomach.
148
What can an ultrasound be used to see
```
Abdominal organs
Heart
Eye and surrounding structures
Soft tissues around spine and extremities
Tendons and muscles.
```
149
What are some advantages to ultrasound
Provide information about organ architecture. Helpful is debilitated or young patients where you Cannot use contrast medium. Able to distinguish solid masses from ones containing fluid. Can do cytology
150
What are some disadvantages to ultrasound
Gas gets in the way of imaging.
Approach is more difficult in a big dog
Great equipment cost
Require lots of training
