RT 201 IMAGING SCIENCE MIDTERMS

Picture Archiving and Communication System (PACS)

a system used to store, retrieve, manage, and store images produced by various medical imaging modalities

Picture Archiving and Communication System (PACS)

reduces the need for manually handling film-based images and provides instant access to images and reports across the healthcare system

basic pacs workflow

order entry, image acquisition, image transfer to PACS, radiologist review, distribution of results

order entry

a clinician orders an imaging exam for a patient

image acquisition

the imaging exam is performed, and the data is acquired

image transfer to PACS

the image data is transferred to the PACS for storage and accessibility

radiologist review

a radiologist accesses the images, performs an interpretation, and generates a report

distribution of results

the report and images are available for the referring physician and others involved in patient care

genetic workflow

refers to a universal approach to handling px data and images from different sources in a standardized and consistent way

genetic workflow

ensures data consistency, better resource management, and easy retrieval across multiple systems in the healthcare facility

Integrating the Healthcare Enterprise (IHE)

it establishes protocols and workflows to ensure that different systems (EHRs, PACS, IT systems) can communicate effectively (feasibility of network)

IHE Radiology Workflow

ensures smooth integration and coordination between radiology departments and other healthcare systems

key components of IHE radiology workflow

scheduled workflow profile, patient information reconciliation

Scheduled Workflow Profile

ensures seamless flow of px information from registration, image acquisition, final reporting, and archiving

Patient Information Reconciliation

resolves inconsistencies in patient demographics that may occur during imaging procedures

steps in radiology workflow

scheduling/order entry, patient registration, image acquisition, image processing, interpretation by radiologists, reporting and communication

scheduling/order entry

the process begins when a physician orders an imaging study

patient registration

accurate px information is entered into the system

image acquisition

technologists perform the imaging study using the appropriate modality

image processing

the images are processed and made ready for review (manipulation of images)

interpretation of radiologists

radiologists read and interpret the images, creating diagnostic reports

reporting and communication

the report is communicated back to the referring physician and any necessary follow-up is conducted

workflow analysis

analyzing the radiology workflow helps in identifying bottlenecks, inefficiencies, and opportunities for automation.

key metrics to analyze in workflow analysis

time from order entry to report availability, image acquisition time, report turnaround time, system uptime and downtime (PACS performance)

less than 5 minutes

standard image acquisition time

data silos

information is not easily shared between departments (information is casted out or isolated)

different formats

of imaging data makes it hard for systems to interpret and share data effectively

security and privacy concerns

especially with sensitive patient information (common issue is hacking)

Health Level Seven (HL7)

a set of international standards for the transfer of clinical and administrative data between HIS; it is essential for sharing data across different health IT systems

HL7

standard format for textual information

DICOM

standard format for images

Internet Standards

utilize standard internet protocols such as TCP/IP and HTTPS to ensure secure transmission of images and reports across networks (for security purposes, prevents potential hacking)

Transmission Control Protocol

TCP

Internet Protocol

IP

Hypertext Transfer Protocol Secure

HTTPS

Digital Imaging and Communication in Medicine (DICOM)

the global standard for the transmission, storage, retrieval, and display of medical images and related information

Digital Imaging and Communication in Medicine (DICOM)

it ensures that medical imaging devices from vendors can communicate with PACS, RIS, and EHR systems

key components of DICOM

file format standard, communication protocols, image compression

file format standard

for images, which include both the the image and metadata

metadata

annotation; information embedded in the image

communication protocols

for exchanging information across networks

image compression

for efficient storage and information transmission of large files

HL7 Overview

crucial for data exchange between information systems; i it covers everything from px records, to lab results, and medical imaging reports

HL7 in Radiology

it ensures that order information, px demographics, and report data are transmitted accurately between PACS, RIS, and EHR systems

Interoperability

it is the ability of different health systems and devices to work together (if there is no network, information has limited access)

IHE and Interoperability

IHE defines integration profiles that specify how systems should communicate to ensure interoperability

Scheduled Workflow (SWF)

coordinates the entire workflow from image order to reporting

Cross-Enterprise Document Sharing (XDS)

allows the sharing of px record, including images, across different healthcare institutions

Quality Evaluation

involves accessing the visual quality and diagnostic usefulness of medical images

Quality Evaluation

ensures that the images produced are adequate for diagnosis minimizing the need for repeat exposures

key parameters for quality evaluation

image quality metrics, subjective vs objective evaluation, artifacts and image degradation

spatial resolution

ability of an imaging system to distinguish small details; measured in line pairs per millimeter (lp/mm); sharpness of the image

contrast resolution

ability to distinguish between different intensities in an image, indicating the differences in tissue density; visibility of the image

signal-to-noise ratio (SNR)

measures the clarity of the image; higher SNR = better image quality

modulation transfer function (MTF)

describes how well an imaging system can reproduce or transfer detail from the object to the image

subjective evaluation

relies on human observers, such as radiologists, to assess mage quality based on visual perception; can be bias

objective evaluation

uses quantitative methods, such as mathematical algorithms and metrics to evaluate image without human bias

artifacts

unwanted things that are not included in the true anatomy

common artifacts

motion artifacts, aliasing, beam hardening

statistical anaylsis

used to extract meaningful information from images such as identifying patterns or quantifying image features

information entropy

measures the uncertainty or randomness within an image; aids in the evaluation of image complexity and data compression technique

mean, median, mode

measures of central tendency that describe the average intensity levels in an image

standard deviation and variance

indicate the spread or variability of pixels intensities, reflecting image contrast

histogram analysis

plots the frequency of occurrence of each intensity value in an image, helping to identify the distribution of pixel values and contrast

information entropy

measures the amount of information present in an image; used in image compression and noise reduction

segmentation

divides an image into distinct regions based on pixel characteristics such as intensity or texture, for further analysis

feature extraction

identifies specific patterns, shapes, or regions of interest within an image

coding and decoding

essential for efficient image storage and transmission

coding and decoding

enables compression, reduce file sizes, and facilitates secure image sharing without losing diagnostic quality

lossless compression

no data loss, og image can be perfectly reconstructed; PNG and GIF

lossy compression

some data is lost, reduces file size; JPEG and MP3

DICOM standard

the standard for handling, storing, and transmitting medical images; contains both image data and meta data

Huffman Coding

a lossless data compression algorithm that uses variable-length codes for encoding symbols based on their frequencies

Run-Length Encoding (RLE)

compresses consecutive runs of the same value, reducing redundancy in images

decoding

converts the compressed image back to its original form, retaining quality based on the chosen compression method

stable signal processing

involves predictable and consistent transformations that preserve integrity

stable signal processing

low-pass filtering and smoothing are examples of

unstable signal processing

may lead to unpredictable changes in the signal, potentially introducing artifacts or altering the og image content

unstable signal processing

common in non-linear transformations or when the input signal is highly variable

gaussian filtering

a linear filter that smooths images by reducing high-frequency components

high frequency components

consumes more process in RAM; high demand in computer performance

median filtering

a non-linear filter that reduces noise while preserving edges by replacing each pixel value with the median of neighboring pixel values

fourier transform and frequency analysis

decomposes an image into its frequency components, aiding in the analysis and filtering of specific frequencies

image transformation

mathematical operations that alter an image to enhance or extract specific features, making it easier to analyze or process

types of transformation

geometric, intensity, spatial and frequency domain, wavelet transform, principal component analysis

translation, rotation, and scaling

modify the position, orientation, and size of an image

affine transformation

includes translation, scaling, rotation, and shear; maintains collinearity and parallelism of points in the image

intensity transformation

modifies the intensity of pixel values to enhance image contrast or visibility of specific features

logarithmic and exponential transformation

enhance dark regions or compress bright regions in an image

spatial domain

direct manipulation of pixel values in an image

frequency domain

manipulation of images based on its frequency components

wavelet transform

decomposes an image into different frequency components, providing both spatial and frequency information; useful for denoising and feature extraction

principal component analysis (PCA)

reduces the dimensionality of an image dataset

principal component analysis (PCA)

highlight major components and eliminating redundancies

pre-medical image processing

involves manipulating raw data obtained from imaging devices to produce a high-quality image that accurately represents the scanned image

types of pre-medical image processing

image reconstruction, background removal, noise removal, image compression

image reconstruction

the process of creating visual images from raw data generated by medical imaging systems

types of image reconstruction

filtered back projection, fourier transform-based methods, iterative reconstruction

filtered back projection (FBP)

commonly used in CT; involves transforming raw data into an image by projecting it onto a grid

fourier transform-based methods

often used in MRI; help convert frequency data into spatial images