RT202 WORKFLOW

RT 202 WORKFLOW

Picture Archiving and Communication System (PACS)

It consists of digital acquisition, display workstations, and storage devices interconnected through an intricate network.

It is an electronic version of the radiologist' s reading room and the file room.

First used in the early 1980 and generally served a single modality - Ultrasound.

Digital Imaging and Communications in Medicine (DICOM)

It is a universally accepted standard for exchanging medical images among the modality, viewing stations, and the archive

It is first completed in 1985

This standard laid thegroundwork forthe future development of integrated PACS.

Image Acquisition

Display Workstations

Archive Servers

Fundamental parts of PACS

Image acquisition

In modern radiology departments, most images are acquired in a digital format; the images are inherently digital and can be transferred via a computer network.

Ultrasound, computed tomography (CT),magnetic resonance imaging(MRI), and nuclear medicine have been digital for many years and have been taking advantage of PACS far longer than general radiography has.

Display Workstations

It is any computer that a healthcare worker uses to view a digital image. It is the most interactive part of a PACS, and these workstations are used inside and outside of radiology

Archive Servers

It is the file room of the PACS. Composed of a database server or image manager, short-term and long storage, and a computer that controls the PACS, workflow. It is the central part of the PACS and houses all of the historic data

Workflow

It refers to the methodical steps involved in a procedure

The entire process of completing an examination from order entry to the transcribed report

Film-Based Workflow

1. Order entry

2. Exam performed

3. Film processed

4. Film interpreted

5. Transcribed Report

PACS Workflow

1. Order entry

2. Exam performed

3. Image processed

4. Image interpreted

5. Transcribed Report

System Architecture

The hardware and software infrastructure of a computer system

1. Client/Server-Based Systems

2. Distributed Systems

3. Web-based Systems

Three common PACS architecture

Client/Server-Based Systems

Images are sent directly to the archive server after acquisition, and are centrally located. It functions as a client of the archive server and access images based on a centralized worklist that is generated at the archive server.

Distributed Systems

The acquisition modalities send the images to a designated reading station and possibly to review stations, depending on where the order originated.

Web-Based Systems

It is very similar to a client/server system in how data flows.

Both the images and the application software for the client display are held centrally: when someone wants to view images from a web-based application, he or she simply searches for the pertinent images, and the web browser will display the images that are held in the web server.

Pixel

Basic picture element on a display

Monitor

Most important elements of a PACS display station

Liquid Crystal Display (LCD)

It is the most popular type of monitor used in a radiology department. It has taken over the entire PACS display market because of its size, resolution, and lack of heat production.

Resolution

The number of pixels contained on a display. It is defined as the process or capability of distinguishing between individual parts of an image that are adjacent.

Pixel and Resolution Relationship:

“The more pixels in an image, the higher the resolution of the image, and the more information that can be displayed.”

Matrix

It is a rectangular or square table of numbers that represents the pixel intensity to be displayed on the monitor

1280 × 1024 (1K)
1600 × 1200 (2K)
2048 × 1536 (3K)
2048 × 2560 (5K)

Common screen resolution

Mammography

requires 5k or 5-megapixel resolution to provide the viewing capacity needed

Cross-Sectional Image

Required only a 1k monitor to view the necessary information

• Primary Reading Stations

• Review Stations

• Quality Control Stations

• Image management Stations or File Room

Display stations category

Radiologist Reading Stations

It is used by a radiologist when making a primary diagnosis.

It has the highest quality hardware, including the best monitor.

Physician Review Stations

It is a step-down model of the radiologist reading station used by a physician. An important feature of this station is the ability to view current and previous reports, along with the images

Technologist Quality Control Stations

It is used to review images after acquisition, but before sending them to the radiologist. This station may be used to improve or adjust image quality characteristics,

File Room/Image Management Stations

It may be used to look up examinations for a physician or to print copies of images for the patient to take to an outside physician. The personnel of this station may also be responsible for correcting patient demographics

Navigation Functions

Used to move through images, series, studies, and patients. The worklist is used to navigate through patients. Most worklists are customizable for the user.

Hanging Protocols

Once a patient has been selected from the worklist, the images load into the display software. It is how a set of images will be displayed on the monitor.

Study Navigation

Is the current or previous examination being viewed.

May comprise two or three single images, as is the case with projection radiography, or it may contain several series of images, as is the case with MRI.

Cine

It is a function (often used in sectional imaging) that allows the user to scroll through a stack of images in sequence, similar to watching a short video.

Close patient or Close study icon

This icon closes the active patient or study and either pulls up the worklist or moves to the next unread patient in the worklist

1. Navigation Functions

2. Hanging Protocols

3. Study Navigation

4. Image Manipulation and Enhancement Functions

Common Functions found on a PACS workstation

1. Window width and Window level

2. Annotations

3. Flip and Rotate

4. Pan, Zoom and Magnify

Image manipulation and enhancement functions

Distance Measurement

Angle Measurement

Region of interest

Measurements

Window width

Represents the range of gray values (Contrast)

Window Level

Represents the brightness

Annotations

Should not be used to label left or right to indicate the patient’s side; digital R and L will not hold up in court because of the ability to mark anywhere on the image and flip and rotate the image into any layout on the screen.

Can indicate prone or supine, 30 minutes, upright or flat, or any other image information the department deems appropriate.

Radiologists frequently place arrows or circles around pathology or questionable areas so that the referring physician can pinpoint what is in question.

Flip and rotate

These functions are used to orient the image in the anatomic hanging position desired by the department.

There are usually left-to-right flip and 90-degree clockwise and counterclockwise icons.

This function makes it very important that lead markers are used to ensure that the radiologist reads the correct side.

Pan, zoom, and magnify

These functions are used primarily by the radiologist to increase the size of an area on the image

Magnify

This function will usually enlarge a square area of the image, and the square can be moved around the image to quickly see various areas enlarged.

Pan and zoom

The image is first zoomed up to the desired magnified level, and then the pan icon is activated so that the zoomed image can be moved around, allowing the user to view the different areas of the image.

Distance measurement

The size of a pixel is a known measurement, so the software can measure structures on the image based on this known measurement.

Angle measurement

Which measures the angle between two structures; this measurement function is commonly used when reading spine studies.

Region of interest (ROI)

Which will determine the pixel intensity of a certain area. Because each type of tissue or fluid has a slightly different intensity reading, the radiologist can make a determination whether something is solid or fluid.

Query/retrieve function

Used to retrieve studies from the archive. The query function allows the user to query a study on multiple fields, such as the patient’s name or ID, date of service, or modality

CD-Burning Option

It is a feature provided by many vendors that allows users to save imaging studies onto a CD for outside use. This function is often limited to the file room, where staff can control and manage which CDs are distributed.

Multiplanar Reconstruction (MPR)

Maximum/Minimum intensity projection

Volume Rendering Technique

Shaded Surface Display

Reading Station Advanced Functions

Stitching

Image Postprocessing

Technologist Quality Control Station Advanced Functions

Multiplanar Reconstruction (MPR)

is a 3D rendering technique that uses thin axial CT slices to reconstruct images in another plane, such as coronal or sagittal. It is commonly used to create coronal images from axial data to reduce patient radiation and scan time.

Maximum intensity projection

used to visualize vessels

Minimum intensity projection

Used to visualize air-filled structures

Volume rendering technique (VRT)

Similar to MIP, but allows the user to assign colors based on the intensity of the tissue so that bone, contrast agent, and organs can be seen in different colors.

The technique uses a histogram-type graph to differentiate the various structures.

Shaded Surface Display

Using a threshold of pixel intensity values, everything below the threshold will be removed, and everything above will be assigned a color and shown as a 3D object.

Stitching

Used when multiple images need to be put together into one image. The most common application is for full-spine X-rays or a scoliosis series.

Image post processing

Is regarded as an advanced function of the workstation, such as edge enhancement, smoothing, and contrast enhancements.