Medical Imaging & upper limb radiology

Question 1

Plain film Radiography, aka traditional X ray, is similar to a 2D shadow of a 3D object. Radiation is absorbed or……………….. by matter, leaving an image on the otherwise exposed film.

Answer 1

Attenuated

* Attenuation is affected by atomic number and the thickness of the material

Question 2

Will a more dense or less dense material show up black on an X ray?

Answer 2

less dense! Ex: air shows up black.

Question 3

Attached is a photo from the slides showing different material in an X ray. What are the 5 radiographic densities?

Answer 3

Air

Fat (oil)

Water (blood, fluid)

Bone

Metal/foreign body

Question 4

In an X ray, the……… sign refers to the loss of normal borders between thoracic structures. It is usually caused by an intrathoracic radiopaque mass that touches the border of the heart or aorta. It can indicate pneumonia.

Answer 4

silhouette

Question 5

Why does proper positioning matter when taking X rays?

Answer 5

Things can be magnified or distorted. We almost always need 2 views at 90 degrees!

Question 6

Often plain film radiography will be enhanced by the addition of contrast media. What are the two most common types?

Answer 6

barium or iodine containing compounds

Question 7

Which tests do NOT use radiation?

Answer 7

Ultrasounds

MRI

Question 8

CT combines the use of x-rays and computers to produce “slices” of the body. It greatly enhances greyscale, so it allows better soft tissue imaging. It is excellent for viewing what?

Answer 8

BONE

Question 9

What are the pros of CT scans?

Answer 9

• Excellent imaging of bone
• Improved soft tissue imaging
• Can produce images in all three planes
• Often the best imaging option available / procedure of choice

Question 10

Cons of CT scans?

Answer 10

• Exposure to ionizing radiation (much more than traditional x-ray)
• Takes longer than traditional x-ray
• Possible allergic reaction if contrast media is used

Question 11

Nuclear imaging is when a radioisotope is used (usually technetium) and is taken up in metabolically active tissues. This provides sensitive, early, physiologic information, not just anatomical info! What are some examples?

Answer 11

Bone scan

Lung ventilation/perfusion studies

Thyroid scan

Stress Thallium study (Heart fxn.)

SPECT=Single Positron Emission Computed Tomography

PET=Positron Emission Tomography

Many others including fused images

Question 12

In a bone scan, what does it mean if there is a “hot spot?”

Answer 12

metabolically active tissues, indicating infection, fracture, or malignancy.

Question 13

Here is an example photo of a PET scan of a normal brain vs a brain with alzheimers:

Answer 13

Question 14

Not all MRIs are the same! It is possible to produce images which enhance different tissue. The two most common scans are T1 and T2.

what will show high signal intensity on T1?

What will show high signal intensity on T2?

Answer 14

FAT

FLUID

Question 15

MRI is typically used for what?

Answer 15

• Neurologic exams (Brain, Spinal cord)
• Musculoskeletal exams (Joints, Muscles, Ligaments, Tendons)

Question 16

CT is often preffered for what?

Answer 16

Chest

Abdomen

Pelvis

Head trauma

Question 17

Pros of MRI

Answer 17

• Unparalleled soft tissue imaging
• Like CT, can produce axial, sagittal, and coronal slices
• Can be used w/ or without contrast media
• NO ionizing radiation

Cons: Expensive, noisy, poor imaging of bone!

Question 18

What are the ABC’s of a radiology report?

Answer 18

Alignment

Bone

Cartilage

Soft tissue

Question 19

When it comes to bone alignment, ……………. is partial loss of continuity, while……………. is complete loss of continuity.

Answer 19

Subluxation

Dislocation

Question 20

When examining bone in radiology, we look at the margins (for breaks in the cortex, or even cracks in the periosteum) and at the density. What do the terms sclerotic and lytic mean when it comes to density?

Answer 20

Sclerotic: brighter white (increased density)

Lytic: darker (decreased density)

Question 21

Just know the concept (regarding periosteum) that a solid or lamellated reaction is less reactive on a test than something causing spiculated borders. Here is a picture:

Answer 21

Question 22

When looking for cartilage, we are examining the spaces on the radiograph for uniformity in contour and size. What is important to know in kids?

Answer 22

¨In children the epiphyseal plates are cartilaginous and can be mistaken for fracture lines.

Question 23

Soft tissue does not image well on plain film X-Rays. Tissue lines show faintly and should be examined beginning from what?

Answer 23

the periosteum to the skin lines.

Question 24

Trauma to bone may produce fragments that penetrate the soft tissue. If a compound fracture has punctured through the skin and then partially reduced, air under the skin may be noted as what?

Answer 24

Black lucency on the radiograph.

Question 25

Inflammation or swelling in soft tissues may be seen by displacement of the surrounding fat pads. What particular bone is this seen in and what is it typically called?

Answer 25

radial head fractures

sail sign

Question 26

There are 2 different protocols for viewing the shoulder, one for non-traumatic and one for traumatic. What are the traumatic views, and why?

Answer 26

AP Neutral

Transthoracic lateral

Axial

* These views are used because they dont require the patient to rotate and move the arm alot

Question 27

Here is a photo of a common shoulder view

Answer 27

Question 28

Here is an axial view of the shoulder:

Answer 28

Question 29

What kind of dislocation is this?

Answer 29

an anterior glenohumeral dislocation

Question 30

What do we need to remember about a radionuclotide bone scan?

Answer 30

It is very sensitive but not very specific. We know if something is going on but we dont know what.

Question 31

Here is an anterior inferior glenohumeral dislocation vs a posterior

Answer 31

Question 32

This is an axial CT. What is wrong with the bone?

Answer 32

The tissue in the lesion is LESS DENSE than normal bone.

Question 33

What are the numbers of this axial MRI?

Answer 33

1= deltoid

2= infraspinatus

3= tendon of subscapularis

4= glenoid of scapula

5= coracoid process

Question 34

For an MRI with contrast, just know that gadolinium will……….. the signal from pathologic tissues.

Answer 34

increase

Question 35

What are the numbers of this coronal MRI?

Answer 35

1= deltoid

2= supraspinatus

3= trapezius

4= glenoid

5= subscapularis

Question 36

What is the 3rd most common malignant bone tumor? (it is about 10% of all primary malignant bone tumors)

Answer 36

chondrosarcoma

Question 37

chondrosarcoma is a slow growing (usually), large soft tissue mass w/ late development of pain. Where is this most common?

Answer 37

Pelvis (pubic rami), proximal humerus, neck of femur, ribs & sternum.