1. The Radiology Information System (RIS)
The RIS is the nervous system of the digital department. Every aspect of the digital department relies in some manner on the RIS.
The RIS drives the workflow of the information of the department.
It is responsible for:
scheduling orders
capturing relevant clinical information about an exam and providing this clinical information only to areas of the department that require it,
preparing prior exams if needed,
providing the PACS with the information it needs to perform its role.

2. Once an image is captured, the RIS and PACS work together to provide the radiologist with the necessary information to interpret the exam and to deliver the report to the clinicians.
In addition to the clinical functions of the RIS, the system manages billing for the exams and provides the necessary data to support management reporting for the department.

3. Scheduling Scheduling is where the process begins.
The scheduling step kicks off a number of events within the RIS to prepare for an exam to be performed.
The process of scheduling an exam captures the appropriate clinical information to determine the exam to be performed.
It is also the point in the process at which the patient demographics are captured. Accurate patient information is required for proper acquisition of relevant prior exam information and to ensure that billing can be performed correctly

5. The RIS provides the technologist and the radiologist with relevant information for performing the exam.
The technologist interacts with the RIS either by;
Receiving a paper request
In the digital environment, by checking an electronic work list that provides the details of the exam, including the protocol assigned by the radiologist.
During this process the RIS tracks the exam status and the patient.
This information is used to manage the rest of the exam transaction.

6. When the exam is complete and the images are ready for interpretation, the RIS and PACS interact to validate that the images acquired match the order information.
Once the images are determined to be valid, the exam data are routed to populate work lists for the appropriate radiology specialty for interpretation.
The delivery methods may include;
Fax,
Secure
Regular mail.
The RIS also serves as an archive for all the exam data, including the report.

7. The Picture Archiving and Communication System (PACs)
Elements of a PACs
Following are the basic elements of a PACS:
Image acquisition
PACS core
Interpretation workstations

9. Image Acquisition
Image acquisition is the first point of image data entry into a PACS, and, as a result, errors generated here can propagate throughout the system, adversely affecting clinical operations.
General predictors for successful incorporation of image acquisition devices into a digital imaging department include ease of device integration into the established daily workflow routine of the clinical environment, high reliability and fault tolerance of the device, simplicity and intuitiveness of the user interface, and device speed. .

10. Digital image acquisition from the inherently digital modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) makes sense.
There are two methods for accomplishing this:
Direct capture
Frame grabbing

11. Direct digital interfaces allow capture and transmission of image data from the modality at the full spatial resolution and bit depth or gray scale inherent in the modality,
Film Digitizers
Film digitizers will still be necessary even in the all-digital or filmless imaging department, so that film images from outside referrals without digital capabilities can be input into the system and viewed digitally.
Film digitizers convert the continuous optical density values on film into a digital image by sampling at discrete, evenly spaced locations and quantizing the transmitted light from a scan of the film into digital numbers.
Several types of film digitizers exist today, with some used more frequently than others in PACS and teleradiology applications.

12. A commonly used film scanner for PACS is the CCD or flat-bed scanner, which uses a row of photocells and uniformly bright light illumination to capture the image. A lens focuses the transmitted light from the collimated, diffuse light source onto a linear CCD detector, and the signal is collected and converted to a digital electronic signal by an ADC.

13. Digital Radiography
Digital radiography refers to devices in which the digitization of the x-ray signal occurs within the detector itself, providing an immediate full fidelity image on a softcopy display monitor.