Midterm/ Quiz 1 Flashcards
Law that Defines that the Intensity of Radiation Decreases with the Square of the Distance from the Source
Inverse Square Law
*Ex. If you Double your Distance, the Exposure Falls off by a Factor of 4 (The Square of the Distance).
Ex. If you Move from 1 Foot from the Machine, to 3 Feet from the Machine, the Exposure Decreases by a Factor of 9
- Spleen > Liver > Kidney
Describe the mAs and kVp for the Pictures Below
Left Picture: High mAs, Low kVp
Right Picture: High kVp, Low mAs
*The Low Contrast (Right Picture) is the “go to” kVp and mAs levels for the Thorax to see the Lungs- For Lung Radiographs we want a High kVp and Low mAs
Machine with Greatest Contrast Resolution of Any Imaging Modality
MRI
*Contrast Resolution: MRI > CT> Digital Radiography > Film
*MRI- Image appearance dependent on Chemical Composition of Tissue- Water, Fat ect.
A Reflected Sound Wave is generated at the Interface of an ____ Mismatch, leading to a Poor Ultrasound
Impedance
*Acoustic Impedance leads to Reflected Sounds Waves = Poor Ultrasounds
*Bone and Air (Lung) create Acoustic Impedance
*Photo- Strong interface between Liver and Lung (Impedance Mismatch)- 100% of the Signal gets reflected resulting in Bad Ultrasound
Free Abdominal Fluid that appears to be Anechoic (Black) is more Likely to be a ______
Transudate
*Free of Protein
Ultrasound of the Liver
What is the White Arrow pointing at?
Hepatic Vein
*No Wall detected
Liver is _____ to the Spleen and has a Coarser Appearance
Hypoechoic
What Pattern of the Small Bowel shows:
- Appearance of Food
Ailmentary Pattern
*Ingesta within the Lumen- Eaten Recently
Digital Images that are Underexposed have more “ Noise” and Appear _____
Grainy
Paramagnetic Compound that Speeds up Proton Relaxation that is useful for Detection of Defectivve Blood-Brain Barrier or Inflammation used only in T1 Sequences
Gandolinium
T2- Weighted
*Fat and Water (CSF) show up White
What is the Correct name for this Radiograph
Right-Left Lateral (Left Lateral)
*The Patients Left Side is touching the Table
In a _____ View Radiograph of the Stomach, the Fundus will be Filled with Fluid and the Pylorus will be Filled with Gas
Left Lateral
*Left side of the Patient is on the Table
Radiographic View where the Pelvic Limbs are pulled Cranially, that is used for looking at the Urethra in Male Dogs
Urethra Shot
*Best for looking for Calculi within the Urethra of Male Dogs
The _____ Ultrasound Transducer, that is best used on Gas Filled Structures such as the Abdominal Cavity
Convex
Convex
*Looks like the Sector but there is a Bite taken out of it- Sector shape with some Clean Shadowing
Chart showing Echogenicity from the Least to the Most
M = Kidney Medulla
C = Kidney Cortex
L = Liver
S = Spleen
P = Prostate
*Kidney is Least Echogenic and Prostate is the Most Echogenic in this list
On Ultrasound, an Empty Stomach may create a _____Sign
Pseudokidney
*Empty Stomach looks Similar to Kidneys on Ultrasound
Radiographic ____ occurs in cases of Unequal Magnification
Distortion
*Femur is Not Shorter, but Appears to be due to Distortion
What Pattern of the Small Bowel is:
- Collapsed State
- Hyperechoic
- Without Acoustic Shadowing
Mucous Pattern
*Common Pattern for Fasted Animal
Part of the Analog (Film) Method of Recording Images that converts X Ray Photons to Light Photons that Expose the X-Ray Film
Intensifying Screens
*When X-Rays strike the Intensifying screen it Converts X-Rays to Light Photons and emits Visible Light. X-Ray Film is Much more sensitive to Light than to X-Rays
*Intensifying Screens permit over 100x Reduction in mAs needed compared to No Screens
What View is this Radiograph of the Stomach
Left Lateral
*Gas is within the Pylorus and Fluid is Within the Fundus
*Left Side of the Patient is on the Table, since the Fundus is located on the Left side of the animal, fluid will run into the fundus due to Gravity
When Radiographing the Thorax with Film, we use a ____kVp and ____mAs, in order to get a Low Contrast Image
High kVp
Low mAs
*We need a Low contrast image with the Thorax
Edge Shadowing
In a Normal Ultrasound of the Spleen and Kidney, the Renal Cortex will be ____ Echogenic than the Spleen and the Renal Cortex will be ____ Echogenic than the Renal Medulla
Less
More
Is this Digital Image of a Canine Head Underexposed or Overexposed?
Overexposed
*Parts of the Anatomy Disappear- No Mandible or Nasal Turbinates. This is Overexposure and the Plate is assigning Black to those Pixels
If you Double mAs, and Decrease kVp by 15%, the new Image will have a _____ Contrast
Higher
*Do this if you want to Change Contrast but Maintain the Same Film Blackness
*You don’t Double or Half the kVp if you are trying to Adjust Technique with Film
Name Roentgen Signs, which are Six Standard Terms used to Describe changes in a Structure in a Radiograph
Size
Shape
Number
Location
Margination
Opacity
Ultrasound Artifact that occurs at Highly Reflective air/fluid interfaces, such as the Diaphragm-Lung and Pericard-Lung Interface, where a False Image is produced on the other side of the Reflector due to its Mirror Like effect
Mirror Image Artifact
*White Line = Lung-Diaphragm Interface
*Picture- Gall Bladder at the Top of the Image is Reflected across the Lung-Diaphragm line to Produce a mirror image of the Gall Bladder underneath the Line
No
*One Tech has an Exposed Hand that will be Exposed to Scattered Radiation
True/False: X-Rays are not Carcinogenic
False
*X-Rays ARE Carcinogenic and if used improperly can lead to the Development of a Tumor
Machine where Mechanical Energy as Sound Waves are transmitted through a patient and returning echoes are detected and the Computer Generates and Image
Ultrasound
True/False: Intrahepatic Bile Ducts are Readily Visible in Abdominal Ultrasounds
False
*Intrahepatic Biliary Ducts are Not detected in Normal Dog and Cats
What View is this Radiograph of the Stomach
Right Lateral
*Pylorus is Filled with Fluid
*Right Side of the patient is on the Table- Pylorus is located on the Right side of the animal therefore Fluid moved into the Pylorus due to Gravity
Right Cranial Lung Lobe Pulmonary Arteries and Veins should be Assessed in a _____ Lateral View
Left
*In the Left Lateral View, the Right Lobe will be the “Up” Lung and will be Easier to View the Arteries and Veins
*You cannot see these Vessels in a Right Lateral View
What Species Tends to Accumulate Fat in their Gastric Wall, leading to the Bands shown in this Radiograph?
Cats
*Completely Normal For a Cat- Fat is responsible for an intramural radiolucent band in the feline stomach wall
Component of ALARA that is Designed to Protect against Scattered Radiation
Shielding
*Some X-Rays bounce off the Patient and Floor. Sheilding is used to Protect ourselves from these Scattered Rays
*Scatter degrades the Image and Increases Personnel Dose
Acoustic Shadowing Artifact that occurs at the Tissue-Bone Interface, where a Substantial amount of Sound gets Absorbed
Clean Acoustic Shadowing
*Clean Acoustic Shadowing- Competely Black Section of Ultrasound
Ultrasound Artifact that occurs at Curved Surfaces, such as the Urinary Bladder and Gall Bladder
Slice Thickness Artifact
Which Ultrasound Machine will Produce a Better Resolution, The 10 Megahertz or the 5 Megahertz?
10 Megahertz
*Image Resolution is Better with High Frequency and Small Wavelength
True/False: We should Always make Right and Left Lateral Radiographs of the Thorax (Lungs)
True
*Always take Right and Left Lateral Radiographs of the Lungs- Lesion may be Seen on One Lateral View and Not the Other
A Structure appears in an Unexpected Location and is Misinterpreted as a Lesion
Superimposition
In Abdominal Radiographs we depend on ____ for Contrast
Fat
In this Plane the Transducer is Towards Examiner Oriented and produces this Type of Image
Transverse Plane
*Cross Section
*Know the Directions of the Sides of the Ultrasound- Right, Left, Ventral and Dorsal- be able to recognize if given a Transverse Image
True/False: A “Frog Leg” Radiograph is the Prefered Method for Radiographing the Abdomen
True
*Frog Leg Radiographs are Prefered Over Radiographs where the Legs are Stretched
*Stretching of the Limbs results in Skin Folds (shown by White Arrows), while the “Frog Leg” Position does Not
Dose Limit on Radiation of Occupationally Exposed Personnel ( you and your Employees)
50 mSv/yr
*Be Smart and Keep to a Minimum
Wire Filament in an X-Ray Tube where a current Passes through the Filament causing Heating and Electrons to “boil” off. Electrons will begin to Flow Toward the Anode
Cathode (-)
*We can control the number of electrons produced by controlling the Magnitude of current passing through the Filament
Radiation can lead to DNA Damage, which often can lead to Failure of DNA Repair and _____ in the Genome. Mutations can lead to Activation of Growth Promoting Oncogenes, Alterations of Genes that regulate Apoptosis and Inactivation of Cancer Suppressor Genes
Mutations
*If the Mutated Cell happens to Undergo colonal Expansion, a Malignant Neoplasm can occur. X- Rays are Carcinogenic
5 mAs, 120 kVp
*The Image is Underexposed. This is an Image of a Thorax- Increasing the Energy is the Better Choice
A Color Doppler indicates in what Direction the Blood flow is Travelling. Blue Color means the Blood Flow is travelling ____ from the Transfuser, while Red Color means the Blood Flow is travelling ____ the Transfuser
Blue- Away
Red- Towards
Creating a Perfect Fim using High kVp and Low mAs will result in ___ Contrast Film
Low
*You can Create a perfect Film with Either a High mAs or a High kVp, however these images will not look the same. the High mAs will produce a High Contrast Film and the High kVp will produce a Low contrast Film
*Picture- Both Radiographs are considered “Perfect” films, however they do not look Identical
In Order to Ultrasound an Equine Abdomen, would a 10 Megahertz or 2.5 Megahertz Machine be Better?
2.5 Megahertz
*Low Frequency will Penetrate Better- Better for seeing Deep Tissues in Horses
*Always use the Highest Frequency Possible that can still Reach the Tissues that you are interested in Examining
Positively Charged Part of the X-Ray Tube which attracts the Electrons. Electrons Strike, leading to Production of many X-Rays
Anode (+) (aka Target)
*The Target (Anode) is positive all the time
Timing Sequence that Nulls the Signal from Fat
STIR
*Gets Rid of the Signal from Fat
*Photo- Lesion More Obvious when Fat Signal Removed
Overexposed
*Dark Radiographs are Overexposed- there are too many X-Rays hitting the Film
In a Patient with Pleural Effusion, when Taking an X-Ray of the Thorax, will the Heart be Visible with the animal in Dorsal Ventral or in Ventral Dorsal?
Ventral Dorsal
*In Ventral Dorsal the Fluid is not surrounding the Heart and the Heart can be Seen
*Ventral Dorsal- Animal is on its Back- Beam Enters the Ventral side of the Patient then Exits the Dorsal Side (The Lungs surround the Heart)
*Dorsal Ventral- Patient is On its Stomach (Sternal)- Beam enters the Dorsal side of the Patient then Exits the Ventral Side (All the Fluid is around in the Heart)
*This is an example of Silhouette Sign- Heart is Hidden by Fluid because they are the same Opacity
Echogenicity is the Same as another Structure with the same Intensity of Returning Echoes compared to Adjacent Tissues
Isoechoic
*Liver and Kindey are Isoechoic in this Ultrasound- Same Echogenicity
Abnormal Ileus that could be Diagnostic for Pancreatitis / Periotonitis
Corrugated
X-Rays are Produced when High speed Electrons strike Metal, which occurs in an X-Ray Tube. What are the Two main components of an X-Ray Tube?
Rotating Anode (Target)
Cathode (Filament)
True/False: Lungs ALWAYS look Better in Lateral Views
False
*Lungs ALWAYS look WORSE in Lateral Views
What Produces a High Signal in a T1 Weighted Image and T2 Weighted Image
T1 - Protons in Fat
T2- Protons in Free Water, Tissue Water and Fat
*Water Does not have signal in a T1 Image and does not show up White
The _____ Ultrasound Transducer will give you a Rectangular Image
Linear
*Linear Transducer may Produce Clean Acoustic Shadowing
The Spleen is ____ Echogenic than the Kidney
More
*The Spleen is Lighter in Color compared to the Cortex of the Kidney
Acoustic Shadowing that occurs at the Tissue-Gas Interface, where 99% of the Sound Wave gets Reflected
Dirty Acoustic Shadowing
*Photo- White Portion on the Left Side of the Photo = Dirty Shadowing
Effect of ____, shows that Increased Opacity in the “Down” Lung Reduces Lesion Conspicuity in the Dependent Hemithorax (Silhouette Sign)
Recumbancy
*Lung Collapses because of Gravity- Lung that no longer has Air will create an Opacity that appears Abnormal. If Radiographed in the VD Position, Lungs would look Normal
*Always take Right and Left Lateral Radiographs of the Lungs to get a Good “Up” View of Both Lungs
- Acoustic Enhancement, Edge Shadowing and Mirror Image Artifact
True/False: This is an Ultrasound of a Completely Full Stomach
True
In What Plane is the Transducer Cranially Oriented and will Produce this type of Image?
Sagittal Plane
*If she Gives and Image and says it is in the Sagittal Plane- Know the Directions of each side: Cranial, Caudal, Ventral and Dorsal- KNOW
Underdeveloped
*The Picture is Over Exposed
*If the Techique was set for Grid but Grid Not used- The Image would be Darker than Normal
*Light Leak in Darkroom- any visible Light is going to Expose the Film, leading to Darker Film
Review Card: Transverse Plane of the Stomach within the Abdomen when looked at from the Cranial View (Looking Toward the Patients Head)
*Normal Orientation of the Stomach in the Abdomen- Patient is Upright (Dorsal Ventral)
*Pylorus is Normally Located on the Right SIde of the Animal
*Fundus is Normally Located on the Left Side of the Animal
Normal Anatomical Ultrasound of the _____
Kidney
*Renal Medulla is Segmented
1.
*Will be Very Similar Questions on the Quizzes and Exams
*If the Distance between the Film and X-Ray Source Decreases the Intensity is going to Increase because you are getting Closer to the Source. Therefore the Answer has to be greater than 1. The Intensity Changes by the Square of the Distance
Which Ultrasound Machine will Penetrate Deeper, The 10 Megahertz or the 5 Megahertz?
5 Megahertz
*Penetration is Better with Low Frequency and Long Wavelength
What is the Anechoic (Black) Round Structure in the Ultrasound of the Abdomen
Gall Bladder
Acoustic Impedance is related to _____, leading to Strong Ultrasound Interfaces in Both Air and Bone
Density
*Air and Bone are called “enemies of ultrasound” because Sound does not Penetrate these Structures. They are not good Structures to Scan with an Ultrasound
*Sound Travels well through the Other Homogenous Tissues
In a _____ View Radiograph of the Stomach, Gas will be Located in the Fundus and Liquid will be Located in the Pylorus of the Stomach
Right Lateral
*Right Side of the Animal is touching the Table
*Gas Bubble Floats into the Fundus
On Ultrasound of the Normal Anatomy of the Liver, ____ are Visible, while Arteries are Not
Veins
*Image shoes Hepatic and Portal Veins- Veins are Visible!
*If you see Tubular Anechoic (Black) structures within the Lumen of the Liver, that will either be Hepatic or Portal Veins
*Will NOT see Bile Ducts and Arteries on Ultrasound of Liver
Artifact that occurs Distal to Highly Reflective Objects (High Acoustic Impedance Mismatch), such as Bones and Air
Acoustic Shadowing
*Interface Absorbs or Reflects entire sound resulting in Anechoic Area
*Photo- Dark Section- Signal has been Lost
Review of Normal Lung Lobe Locations
*4 Lung Lobes on Right Side- Cranial, Middle, Caudal, Accessory
*2 Lung Lobes on Left Side- Cranial (2 Parts), Caudal
How can you Distinguish the Hepatic Vein from the Portal Vein on an Ultrasound of the Liver?
Portal Vein is Surrounded by a Thick White Wall
Hepatic Vein is NOT surrounded by a Wall
- High Frequency, High Resolution, Low Penetration
What Artifact can be Identified on this Ultrasound of the Liver
Mirror Image Artifact
*Mirror Image of Liver can be seen on the other side of the Lung-Diaphragm Interface
In an Ultrasound, the _____ Head is Fixated at the Greater Curvature of the Stomach at the level of the Costal Arch
Splenic
*Entire Spleen has to be examined- Head, Body and Tail
*Spleen- Hyperechoic Capsule with Smooth Margins and a Homogenous Fine Granular Appearance
True/False: This Radiograph Demostrates Lytic Lesions in the Ischium of the Pelvis
False
*The Black Circles in the Pelvis are Gas Distended Anal Sacs Superimposing on the Ischium
A _____ Radiograph is too Light, meaning either the kVp or mAs is too low
Underexposed
*Low kVp or mAs leading to Fewer Electrons and thus Fewer X-Rays- not enough X-Rays are hitting the film
Always try to Scan _____ to the Surface when Preforming an Ultrasound
Perpendicular
*Ideal Approach- The sound will come back straight to the Transfuser rather than be Reflected or Refracted
Best Plane to Ultrasound the Kidney to Diagnose Hydronephrosis (Water in the Kidneys)
Transverse Plane
*If you suspect Hydronephrosis, you ALWAYS focus on the Transverse view
Higher Echogenicity than other Structures that in General Refers to White Structures with High Intensity of Returning Signals
Hyperechoic
*The Spleen is Hyperechoic
Light Leak in Darkroom
*Visible Light will Expose the Film and Cause it to be Darker
Radiograph is too Light. What Two things can you do to Fix the Problem?
Increase mAs
Increase kVp
*Increasing mAs will increase the number of X-Rays and Increasing kVp will create Higher energy X-Rays which are more likely to hit the film
*The Original Radiograph had an mAs or kVp that was too low, therefore not enough X-Rays were being produced
What Pattern of the Small Bowel shows:
- Anechoic Luminal Content
Fluid Pattern
No
*The Guy Holding the Cassette is in the Field of the Primary Beam
Rib ___ is a Useful Reference for Right Caudal Lobe Pulmonary Arteries and Veins
9
*The Vessels in the Caudal Lobe should be About the Same size as the 9th Rib
What Pattern of the Small Bowel shows:
- Hyperechoic
- With Acoustic Shadowing
- Walls often appear less Distinct
Gas Pattern
*Commonly see in Unfasted Patients
True/False: This is an Ultrasound of a Completely Full Stomach
False
*This is an Ultrasound of a Fairly Empty Stomach- Rugue of the Stomach are Visible
Dogs have a Distinct Coiled _____, while Cats have no appreciable _____
Cecum
*In the dog we see the cecum radiographically and in the cat we never see the cecum
*Gas filled structure in the Middle of the Dogs Abdomen- Cecum
Ultrasound of the Liver
What is Represented by the Red Line?
Lung-Diaphragm Interface
Echogenicity that is Less Echoic than Other structures that refers in general to Medium Gray Tones with a Low Intensity of Returning Signals
Hypoechoic
*Less Echogenic
*Photo- The Liver would be Hyoechoic compared to the Spleen
List The 5 Opacities
*Water AKA Soft Tissue
*Metal is the Most Opaque and Air is the Least Opaque
*Something that is Opaque is White and Something that is Radiolucent is Black
What is the View of this Radiograph Taken of the Stomach
Ventral Dorsal
*Fluid is Within the Fundus and the Pylorus is filled with Gas
Summary Slide
*Pictures of the Abdomen- For the Abdomen we want High Contrast- Low kVp and High mAs
*Know the kVp and mAs for the Abdomen and Thorax
Creating a Perfect Film using a High mAs and Low kVp, will result in ____ Contrast Films
High
What Mode of Ultrasound does this Represent?
B-mode
*Brightness Mode- Brightness reflects intensity of the Signal
- 1: Clean; 2: Dirty
What are the 5 Layers that make up the Intestinal Layering of the Small and Large Intestine?
Serosa- Hyperechoic
Muscularis- Hypoechoic
Submucosa- Hyperechoic
Mucosa- Hypoechoic (THICKEST)
Lumen-Mucosa Interface- Hyperechoic
Echogenicity that is Homogeneously Black with Very Low Intensity of Returning Echoes
Anechoic
*Photo- Bladder is Anechoic
*Anechoic structures in Ultrasound are usually Fluid Filled
Yes
*Assuming they have aprons on and the X-Ray machine isn’t leaking, it is acceptable to hold the X-Ray machine and the Person holding the cassette has on Gloves and is outside of the Primary Beam
Summary Picture of Radiography, CT, and MRI
*Best Detail- Radiography
Best Contrast Resolution- MRI
Special Case of Superimposition where Overlapping Structures create a Summation Opacity that is Not Really Present in the Patient
Summation Sign
True/False: Bone shows Up White in an MR Image
False
*Bone is Black in an MR Image- Bone and Air Give no Signal in MR Images and therefore appear Black. Water and Fat appear White
Ultrasound of the Liver
What is the Blue Arrow Pointing at?
Portal Vein
*Hyperechoic Wall
Be Able to Identify the 5 Opacities
Wet Hair
*So much water in the hair- it has enough density that it is absorbing X-Rays
*Static Electricity is Black
The Moment the Sound Signal goes through a Fluid Filled structure, such as the Gallbladder, the Ultrasound machine Overcompensates, leading to this Artifact
Acoustic Enhancement
*Fluid of Homogenous Acoustic Impedance attentuates less sound than the surrounding tissue
Ultrasound Artifact that is Characterized as a Small Shadow at the edge of Round Structures
Edge Shadowing
CT
*Bone is White
Normal Anatomical Ultrasound of the _____ Vein at the Hilus
Splenic
2 or 4
*The Film is Overexposed
*Either Half the mAs or Decrease kVp by 15% in order to make the Image Lighter
An _____ Radiograph is too Dark, either the kVp or mAs is too High
Overexposed
*Too many X-Rays are hitting the Film
In a _____ View Radiograph of the Stomach, Fluid will Run into the Fundus and the Gas Bubble will be within the Pyloric Antrum
Ventral Dorsal
*Patients laying with Back on the Table
What is the Correct Name for this Radiograph?
Left-Right Lateral (Right Lateral)
*Point of Entrance to Point of Exit- The Patients Right Side is on the Table
*Right Lateral- The Patients Right Side is Touching the Table
Digital Images that are Overexposed become _____ and Anatomy Disappears
“Saturated”
*Look at the Tail in the Image- It is so Overexposed the Image “Drops Out” aka Saturated. The Anatomy of the Tail Disappears in the Radiograph
The Effacement (loss of Visualization) of the Border of Two Structures of the same radiographic opacity that are in contact
Silhouette Sign
*KNOW THIS- very important
*Two Structures with the same Radiographic Opacity are in Contact, therefore you Can’t Visualize the Border of the Structures
Timing Sequence which the Magnet Primarily “Hears” Protons in Tissue Water, and Gets rid of Protons in Free Water
FLAIR
*Photo- CSF Is taken away in FLAIR Image. Lesion More Obvious when CSF (Free Water) is Removed
The _____ Ultrasound Transducer, that is best used for Echocardiology
Sector
*Best to use for Echocardiology
