lec 1 computer concepts

informatics

how data and info are collected, organized, used, shared

informatics in healthcare

supports pt care, communication, decision making

imaging informatics connects images with

pt info, clinical workflow, systems that manage it all

order of informatics in nuclear medicine

order/pt ID → acquisition → processing → storage and transfer → interpretation and report

why do technologists need informatics

when data is saved under incorrect pt, study, etc; incomplete data transfers, technical problems

analog signal

continuous waveforms

infinite value range

susceptible to interference and noise

high fidelity in reproducing og info

smooth transitions bw values

digital signal characteristics

discrete values (0 and 1)

limited value range

resistant to noise and interference

high accuracy in data transmission and storage

stepwise transitions bw values

noise can cause ___ for analog signals

distortion

digital signals are less prone to ___ during transmitted

signal degradation; ensures received data matches what was transmitted

analog is better for ___

long-distance transmission; digital may require signal boosting

digitization

process of converting analog info into a digital format

information is lost in digitizing process!

what type of signal does imaging equipment use?

both; analog from detectors as electrical pulses proportional to radiation energy; these signals must be converted to digital for image reconstruction, storage, analysis

analog-to-digital conversion (ADC)

determines resolution and precision; relate to sampling rate and bit depth, which affect spatial res, contrast, noise levels

analog problems

signal distortion, electrical interference

digital problems

quantization errors, data corruption

what is a quantization error example

energy window for tc99m centered at 140 kev; analog for a photon may correspond to 140.3 kev, but ADC step size only allows 140 or 141 kev.

system records 140 kev only, losing 0.3 kev of precision.

over thousands of counts, these errors can slightly affect energy discrimination/image uniformity

digital signals allow integration w picture archiving and communication systems (PACS), enabling…

storage, transmission, processing

understanding digital formats (DICOM) is critical for

compliance and interoperability

binary number system

digital code consisting of only 0s and 1s

primary language of any digital computing system

binary system: is read ___, and value of each position is ____

read right to left

value is 2^x

boolean algebra

branch of mathematics that provides a set of operations and rules to manipulate and process binary variables

0- false

1- true

boolean algebra is the foundation of

digital electronics and computer science- uses logical operators

boolean algebra: logical operations

AND vs OR

boolean algebra: AND

result is true (1) only when all input values are also true (1)

represented by a dot (.)

A AND B would be A.B

boolean algebra: OR

result is false (0) only when all input values are also false (0)

A OR B would be A+B

boolean algebra: NOT

result is false (0) if input is true (1) and vice versa

NOT A would be ~A or A’

there are other logical ops and rules used to perform complex tasks

bit

short for binary digit

smallest unit of info

can only hold a single 0 or 1 (2 options)

byte

abbreviation of binary term

8 bits almost always

2^8 = 256 options

word

number of bits or bytes processed simultaneously by a computer (32 bits, 64 bits, etc)

memory sizes are often expressed in what

powers bc digital systems use binary (2^x)

the official SI system defines kilo and mega as what?

kilo: 1,000 : 2^10

mega: 1,000,000 : 2^20

memory (RAM) usually uses

binary multiples

storage (hard drives, SSDs) often use

decimal multiples (10³ , 10^6)

KiB (kibibyte) and MiB (mebibyte)

1,024 and 1,048,576, respectively

if a gamma cam image req 512 KiB of storage, how many bytes is that?

512 × 1,024 = 524,288 bytes