Medical Imaging Flashcards
More dense structures appear _____________ on the xray
Lighter
What is preferred for the view of the heart
Posteroanterior, AP shows an enlarged view of the heart but can be used when the patient cannot stand
Describe fluoroscopy
Heart caths with Dr. Vijit
What allows you to isolate the arteries in imaging
Digital subtraction
What are the disadvantages of CT? What are the advantages?
D
- lots of ionizing rad
- renal function must be questioned for contrast
- some are allergic to iodine
A
- quick
- generates lots of data usable later
- can be manipulated after the scan
- motion not as much an issue
What is the scale used to measure CT density?
Hounsfield
What is the density of: water, air, compact bone, and soft tissues
0, -1000, +3095, -100 to +100
What do numbers below the window look like? Above?
Black
White
What are the advantages of MRI? Disadvantages?
A
- no ionizing rad
- better soft tissue contrast
- extremely versatile
D
- longer than CT
- loud
- claustrophobic
- images cannot be altered
- no metal in body
- more expensive
What appears dark on T1 weighted MRI
Tumor
Inflammation
Infection
Hemorrhage (hyperacute or chronic)
What appears dark on T2 weighted MRI?
Calcification
Fibrous tissue
Protein rich fluid
What is a narrow window good for looking at
Soft tissues
What is a wide window good for looking at
Bone
What is the function of connective tissue?
- Structural framework of the body
- Protection
- Supports and interconnects other tissues
- energy storage
- transport things
- defense
What do fibroblasts produce?
Collagens, proteoglycans, and glycoproteins
What do mesenchymal cells do?
They are connective tissue stem cells
What do adipocytes do?
Store and release fat
What do chondrocytes do?
They produce and maintain cartilage
What do osteoblasts do?
Produce bone components
What are hematopoietic stem cells responsible for?
Produce red blood cels and immune cells
What is the most common form of collagen?
Type 1
What are the fibrous components of the ECM?
Collagen, elastin, reticular fibers
What are reticular fibers primarily made up of?
Type 3 collagen
What are the two main type 1 collagen fiber defects?
Scurvy- vitamin C deficiency which is a cofactor for cross-linkage
Ehlers-Danlos - abnormal collagen synthesis leading to weak collagen fibers
What is the main defect in marfans
Mutation in fibrillin-1
What are long limbs called?
Arachnodactylyl
What are the properties of embryonic connective tissue?
Rich in ECM, rich in mesenchymal cells, not many collagen or reticular fibers, in umbilical cord referred to as Warton’s jelly
What do adult mesenchymal stem cells differentiate into?
Fibroblasts, muscle (both sm and skel), osteoblasts, chrondroblasts, adipocytes
What are the 3 types of loose connective tissue
Areolar, adipose, reticular
What is areolar connective tissue
Low density tissues with both fixed and wandering cells
it is found around blood vessels, muscles, and nerves
Functions to support and bind other tissues, holds body fluids, and defends against infection
How is adipose tissue characterized?
It is a loose connective tissue characterized by sparse ECM and abundant adipocytes
What do reticular fibers function in?
Forms an open framework to hold free cells
Found in liver, bone marrow, lymph nodes, and spleen
What are the types of dense connective tissue?
Dense, irregular; dense, regular; elastic connective
What is the function of dense irregular connective tissue?
Protect internal organs, functions in dermis of skin, fascia, perichondrium, and periosteum
What are the principle cell type of dense, irregular?
Fibroblasts
What is the purpose of dense, regular CT?
Resists pulling
They are arranged in parallel bands
Found in tendons, ligaments, aponeuroses, dense fascia, and joint capsules
What does dense irregular appear as when not under load?
Wavy
Where is elastic CT found?
Around blood vessel walls, bronchiole tubes, special ligaments
