Studied by 12 people
Radiographic Exposure
HIS (Hospital Information System)
Contains patient medical records (EMR) & sends radiology orders to RIS
RIS (Radiology Information System)
Creates worklist and merges patient data with radiology exam fields
PACS stands for:
Picture Archiving and Communication System
PACS is a computer system used to _____, _____, and _____ images from digital modalities.
acquire
display
transmit and score
Functions of PACS (3 things):
integrates medical record on HIS with RIS
displays acquired images through hospital network
allows images to be accessed over the internet
Exposure indicator is what and indicates what?
A number indicating the average radiation exposure to the IR in order to form a CR image.
May indicate under or over-exposure.
DICOM stands for what?
Digital Imaging and Communication in Medicine
What is DICOM?
A STANDARD that establishes RULES for the exchange, display, and storage of medicine images and text.
RAID stands for what?
redundant array of independent disks
What is RAID?
A group of hard disks that provides data protection and improves data acquisition speed.
minimum scale bit depth for dicom
2.5 mm/lp
What is Moire Pattern?
Appearance of grid lines caused by the scan frequency and direction matching that of grid.
Exposure number means? — what +3 or -3 means — and what to do with kvp and mas
DQE stands for what?
Detective Quantum Efficiency
What is DQE?
The ability of a detector to convert x-ray to a useable signal based on measurement of the combined effects of CONTRAST and NOISE on the imaging system.
DQE values will always range from:
0 to 1
Advantages of CRT monitor (2 things):
Less expensive than LCD
Can see image at sharp angles to monitor
Disadvantages of CRT (4 things):
blooming
soft copy veil glare
glare
luminance
Advantages of LCD (Liquid Crystal Display) 6 advantages:
higher luminance than CRT’s
produce less heat
no veil glare
less reflection glare
less maintenance
less power consumption
Disadvantages of LCD (2 disadvantages):
more expensive than CRT’s
limited field of view from extreme angles
Dynamic range — how its read out
Gray scale bit depth
What is dynamic range?
the number of shades of gray that can be displayed on an imaging system.
More on dynamic range (2 things):
response is linear
all digital images have a wide dynamic range
How much file storage space is needed for DR images if there are 10 images and the matrix size is 1,000 X 1,000 with a 12 bit depth?
1,000 X 1,000 = 1,000,000
1, 000,000 X 12/8 = 1,500,000
1,500,000 X 10 images = 15 Mb
ACR requires a minimum spatial resolution of at least:
5 lp/mm
What is KERMA?
Kinetic energy released in matter is used to express radiation concentration delivered to a point by radiographic and fluoroscopic equipment.
KERMA is formally defined by the amount of energy released per kilogram of _____ in _____.
air
Gya
When KERMA is written to express absorbed dose in _____ it is denoted as _____.
tissue
Gyt
What is KAP?
Kerma Area Product
____ is defined as contrast seen in the image divided by the amount of noise existing in the image
CNR (contrast-noise ratio)
Where should the IR plate be read out?
The middle — center points
Three types of monitors:
Consumer grade monitors
Medical displays
View boxes
Consumer grade monitor range:
250 — 300 (cd/m2)
Medical displays
300 — 500 (cd/m2) or 170 nits
Viewboxes: low intensity, high tensity, and average
Low: 1000 — 2000 nits
High: 2000 — 3000 nits
Avg: 1700 nits
What is HL7 (Health Level - 7)?
An international organization that develops standards related to exchanging information between medical applications.
What does HL7 aim to improve?
“interoperability” of healthcare information along with improving workflow, decrease ambiguity and share information between providers of healthcare
Lossless compression ( 2 things):
No loss of image fidelity between original and decoded image
Typically 2:1 or 3:1 compression
Lossley compression
Higher compression that may lose image detail after being decoded
Note 
Flashcard (63)