Diagnostic Imaging Flashcards
What are the main goals of using imaging studies?
Assist in:
1) Establishing a diagnosis
2) Guiding development of plan of care
3) Don’t treat image, make sure image and clinical exam both make sense
What are interventional radiologists?
Interventional radiologists are MDs that specialize in providing treatment that are done in the presence of imaging techniques for example - imaging guided facet injections
1) Provide treatments
2) Special procedures for pain relief
3) Minimally invasive procedures are replacing open surgeries: Radiofrequency treatments, biopsies
Name the 7 types of imaging studies
1) Plain films (Radiographs or x-rays)
2) Magnetic Resonance Imaging (MR,MRI, MRA)
3) Tomography/ Computed Tomography (CT)
4) Radionuclide Bone Scans
5) Fluoroscopy
6) Arthrography
7) Sonography
What type of imaging study is routinely 1st performed?
Plain film (radiographs or x-rays)
Plain films-Bones/structures are 2D or 3D?
3D
Plain films-How many views do you need for an adequate exam?
2 views for an adequate exam
Plain films-In the C spine, how many views are needed for the exam? What type of “special” view should it include for C1-2?
- Need 5 views for the exam
- Should include “open mouth” view (C1-2) in addition to P/A, laterals, oblique
X-ray beam-For less pentrating, does energy, wavelength inc or dec? How about to penetrate deeper? Give an example of an x-ray using low energy
Less penetrating: Decreased energy -> increased More penetrating: Increased energy -> decreased wavelength
Mammography - low energy
Plain films-Shade black to white or white to black?
black to white
Plain films-What color is air?
Black (no density)
Plain films-What color is soft tissue?
gray
Plain films-What color is bone?
white?
Plain films-Tissues with most density will be what color?
White
Plain films-Which structures are best visualized?
Bone
Plain films-Tend to diagnose via ___ (For example 30-50% loss of bone loss - osteoporosis)
-Via omission, in what is not there
Which imaging study is cheapest and considered the gold standard?
plain films
Name 6 things that plain films aid in evaluating
1) Trauma
2) Bone quality (mineralization)
3) Joint status
4) Placement and location of support lines and/or tubes
5) Dental evaluation
6) Presence of mineralization in a structure or mass
Plain films-What is the acronym when reading plain films? Briefly discuss each one.
A: alignment
B: bones
C: cartilage
S: soft tissue
A stands for Alignment.
The reference for this is normal anatomical position. For example, any break in the cortex, indicates a fracture. Severe deformity can be a sign of disease, trauma, etc. Imaging studies are often just one piece of establishing a diagnosis.
B stands for Bone quality.
Quality of cortex. 1/3 – 2/3 rule ( cortex of a healthy long bone should be 2/3 of it’s diameter;
Sclerosis (more dense, increased lucency); cortex (more lucent, thus less contrast)
C stands for Cartilage.
Examination via exclusion. This is when the radiologist looks at the joint spaces. The health of the cartilage is an indirect measure….when a joint space appears narrowed (and often there are other changes noted at the joint margins such as osteophytes), cartilage degeneration is present.
S stands for Soft Tissues.
Normally, you don’t see the soft tissues very well on radiograph. However, in the presence of effusion or calcification, the soft tissues become visible. Their presence often indicates an active pathological process.
Plain films-Name 3 clinical judgements plain films can assist with
1) WB status
2) ROM
3) Intensity of exercise
These are typically determined by a MD
When describing fractures, what terms do you use to descrbe the location?
Location: Long bones divided into thirds
a. proximal
b. middle
c. distal
When describing fractures, what terms do you use to descrbe the pattern?
Pattern:
1) Transverse
2) Transverse with butterfuly fragment
3) Spiral
4) Oblique
When describing fractures, what terms do you use to descrbe the alignment?
1) Long Ais
2) Varus
3) Valgus
4) Anterior
5) Posterior
When describing fractures, what terms do you use to descrbe the position?
1) Reference is normal anatomy
2) Shortening
3) Subluxations
4) Dislocations
What 4 categories are used to describe a fracture?
1) Location
2) Pattern
3) Alignment
4) Position
MRI/MR/NMR-Primarily used to visualize what?
Soft tissue visualized
-Ligaments, muscle, tendon
What is a Scout Film?
Scout Film –taken in the appropriate plane (sagittal, axial, coronal). Dotted lines at the specified intervals (of the films taken) are drawn through the scout film and labeled with a number. When you match the numbered sequence to the line in the scout film, it allows you to precisely identify the structures that will be visible.
MRI: Proton spin density weighted images (or just spin density) is what?
concentration of protons detectable by MR
MRI: Name 2 tyes of proton spin density weighted images
1) T1
2) T2
MRI: T1 is used to define what? fluid/fat, which one is dark, which is bright?
T1: is the sequence used to define anatomy – Fluid dark /fat bright
MRI: T2 is used best to study what? fluid/fat, which one is dark, which is bright?
T2: is best for studying pathology – especially fluids which are bright ; fat dark
MRI/MR/NMR: Name 4 musculoskeletal indications
1) Tears
2) Degenerative changes
3) Inflammation
4) Early detection metastatic disease
- Highly sensitive and highly specific!
MR is excellent detecting early what?
metastatic disease. disease.MR is highly sensitive and specific for detecting fluids and since mets are of vascular origin, it’s more specific than bone scans (although much more expensive).
What imaging study is the study of choice in examining joint pathology? Used to determine tears, e.g. rotator cuff, meniscal. increased enhancement &/or leakage
MR with contrast
Define Tomography
Technique for obtaining a series of radiographs at consecutive planes through a body part
What is the primary use of tomography?
Nonunion fractures, status of bone healing
Which imaging studies use scout films?
CT and MRI
CT scans are good for these 3 things
1) Excellent bone images
2) Detect burst fractures
3) Detect disc lesions
CT OR MRI? Chest
CT
CT OR MRI? Head, Spine
MRI
CT OR MRI? Extremities, Joints
MRI
CT OR MRI? Fx Detection
MRI
CT OR MRI? 3D Images
CT
CT OR MRI? Fx Treatment Planning
CT
CT OR MRI? Abdomen
CT
Bone scans-high or low sensitivity?
High senstivity
Bone scans-high or low specificity?
poor specificity
Bone scans-Name 4 screening tools used in bone scans
1) Tumors - metastases
2) Infection
3) Arthritis
4) Stress fractures
Name 2 imaging studies that are one of the earliest means to detect stress fractures
1) Bone scans
2) MRI
Define Fluoroscopy, what’s different about it?
Uses radiography in real time fhasion, patient voluntarily moves through ROM
Which other imaging studies can add a dynamic component to radiographs?
CT and MRI
What’s the disadvantage of Fluoroscopy compared to arthrogram?
resolution not as good
When is fluroscopy used?
Fluoroscopy is routinely used for special procedures (across systems). E.g Barium swallow, GI Studies, GU – bladder studies; Epidural injections, rhizotomy (surgical resection of the spinal nerve root – pain relief)
Arthrography-How are films enhanced?
Films enhanced with contrast
Arthrography-Used to detect which 4 things?
1) Inflammation
2) Soft tissue tears
3) tendinitis
4) capsulitis
Arthrography-What is the advantage over MRI/CT?
cheaper
Which imaging study can aid in diagnosing ligamentous injuries of the wrist, shoulder?
arthrography
Which imaging study is used for anatomical referece in special procedures?
arthrography
Which imaging study is now being replaced by MRI, CT with contrast?
Arthrography
Define Sonography
Imaging method which bounces sound waves off structures
Name 5 indications of sonography
1) Diagnosing DVT
2) Defining fluid collections (joint effusions)
3) Mostly abdomincal and pelvic imaging
4) Pleural fluid collections
5) Superifical chest wall masses or fluid
What type of “effect” is used in sonography?
Doppler effect
Sonorgraphy-Disadvantages?
Limited use in Thoracic imaging
RC-Radiography-Best view? How far should the humeral head and acromion be?
- AP with UE in neutral
- distance between humeral head and acromion < 6 mm
RC-Radiography-What type of evidence of changes in rotator cuff pathology?
Indirect Evidence of changes in rotator cuff pathology
RC-Radiography or MRI? Eval of osseous anatomy and abnormalities
Radiography
RC-Radiography or MRI? Able to assess osseous and soft tissue structures
MRI
RC-Best seen on T1 or T2 weighted sequence?
T2
RC-MRI-What % are you able to see partial thickness tears?
able to see tears of <= 50%
RC-MRI-In a full thickness tear, what will be positive findings?
-Discontinuity/detachment and fluid from articular to bursal surface
RC-MRI-Best to have images in how many planes?
Best to have images in two planes, able to measure and determine location
RC-MRI-Sensitivity and Specificity in complete tears?
- Sensitivity - 100%
- Specificity - 95%
RC-MRI-Sensitivity and Specificity in partial tears?
- Sensitivity – 82%
- Specificity – 85%
