All the Differences Between RIS, PACS, DICOM, and CIS

Published February 02,2022

Within the healthcare environment, there are several medical workflow management systems that are employed on a daily basis. Many, if not all, are frequently found in radiology practices and departments. Understanding RIS, PACS, DICOM®, and CIS systems, the differences between them, and how they work, individually and collaboratively, requires a solid base of knowledge of each system’s definition, their most prevalent usages, along with the key benefits and advantages in their implementation.

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Four of the most leveraged radiology systems include RIS, PACS, DICOM, and CIS, which will be discussed in detail within this blog through these questions:

What is RIS?Radiology Information System
What is PACS?Picture Archiving and Communication System
What is DICOM?Digital Imaging and Communications in Medicine
What is CIS?Clinical Information System


Ready to take the leap into the illuminating world of RIS, PACS, DICOM, and CIS and identify the difference between the systems.


What is RIS?

A Radiology Information System (RIS) is a root system used for electronic management by imaging departments. A RIS is a radiology-specific software solution geared to procuring, storing, and sharing medical imaging data and is used extensively throughout the healthcare sector. Designed to optimize efficiency of radiology workflows, a RIS can be used in conjunction with a Hospital Information System (HIS) and/or Picture Archiving and Communication System (PACS).


benefits of RIS healthcare diagram


RIS in the Hospital System

RIS is effectively used in hospitals for the tasks below:

  • Patient Scheduling and Tracking – With a RIS, clinicians can easily access patient medical histories, track treatment statuses, process patient registrations as well as organize appointment scheduling. Time-savings are considerable with the reduction of paper-based documentation and a simplified, automated booking process that a RIS can offer.
  • Document Management – Since a RIS system is constantly updated, patient data integrity is assured and always ensures patient files are readily accessible when needed by clinician teams. Interactive documents can also be generated in a RIS which contributes to enhanced inter-physician communication and more timely diagnosis facilitation.
  • Image Identification – A RIS system ensures patient data is correctly attributed to the appropriate corresponding images generated thereby allowing for easy identification while minimizing the risk of study mix-ups.
  • Billing and Reporting – A RIS plays a key role in optimizing radiology-centered billing and reporting by way of storing financial records, facilitating data analytics, automating billing, and processing electronic payments.
  • Modality Interfacing – Worklist utilization and modality intercommunication is made more seamless in a RIS which translates to faster processing of medical images and superior quality control.


Together, the above RIS functions work to cultivate streamlining the radiological diagnostic process towards reducing waiting times, improving accuracy, and thereby, foster the delivery of consistent, responsive patient care. Let’s look more in-depth at the advantages that can be expected from the application of a RIS:


The Benefits of a RIS

On the whole, the immediate benefits of utilizing a RIS all culminate in a faster, more reliable way of handling patient information — the process of diagnostics is enhanced, risk of staffing shortages is diminished, and data entry errors are tremendously limited to include just a few!

A RIS can be essential towards providing a seamless, comprehensive service model for patient care. RIS imaging can be a profound asset in decentralizing radiology delivery from expediting physician work and augmenting inter-physician communications to enabling real-time patient tracking towards better workflow management, all resulting in quicker diagnoses. Innovations from using a RIS allows a radiology practice to devote their focus to what matters most: patient care delivery.

On the administrative side, by streamlining operational procedures and implementing time-saving digitization of paperwork, RIS systems can make things so much simpler for a healthcare provider’s administrative team. This includes managing supply budgets as well as radiology-related materials.

And finally, cost reduction. All benefits as outlined above contribute to increased revenues and a “healthier” bottom line.


What is PACS?

Picture Archiving and Communication System (PACS) is a medical imaging technology that provides data storage and convenient image access from multiple modalities. It is a common software solution used predominantly by hospitals and healthcare organizations. Built for to securely store and transmit electronic patient images and data, a PACS system eliminates the need for traditional methodologies involving manual file management (e.g. film jackets) and delivery.

Though radiologists have been the main users of PACS systems, as well as being leading generators of x-ray images, PACS has also been implemented into other health-related fields including cardiology, oncology, dermatology, pathology, and nuclear medicine imaging. In light of its prolific usage, a PACS is designed to handle image formats produced from a wide variety of modalities such as mammograms (MG), magnetic resonance (MR), ultrasound (US), computed tomography (CT), and digital radiography.


Functions of PACS


By leveraging a PACS, clinicians can easily access their patient information digitally. Digital access signifies accelerated and improve care, minimized chances of treatment and prescription errors, in addition to the circumvention of unnecessary testing performed.

DICOM, a worldwide-recognized standard protocol for the administration and transmission of medical images and data, is responsible for the present-day application of PACS. To have a better understanding of DICOM and the differences between DICOM and PACS, please continue reading the article.


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Get a more comprehensive understanding of PACS and RIS/PACS integrations by taking a deep dive with our comprehensive PACS and RIS Guide.




What is DICOM?

Digital Imaging and Communications in Medicine (DICOM) is the globally recognized communication and management standard for medical images and other patient data. It is frequently utilized throughout the medical field to store and transmit medical images facilitating integration with medical devices and PACS systems. Its broad clinical adoption includes hospitals, radiology practices, and most recently, in doctors’ and dentists’ offices.

DICOM Standard

DICOM® is the global standard for medical imaging transmission and storage. Since its establishment in 1993, the DICOM standard has been the touchstone in the transformation of the radiological practice from x-ray film to a digitized workflow. The published standard, whose copyright is held by The National Electrical Manufacturers Association, was developed by the DICOM Standards Committee (which consisted of many NEMA members). DICOM is recognized as the ISO standard 12052.


DICOM exists as both a communication protocol as well as a format type. Saving medical images under the format safeguards that all the data relating to a particular study (i.e., patient information, medical image, etc.) remains together, allowing for seamless transmission between DICOM-compatible devices translating to easier patient data sharing between clinicians and a quicker diagnostic process.


A file is an image saved in the DICOM format. Within it, a medical image generated from a modality (e.g., MRI, scanner, ultrasound, etc.) is enclosed, along with metadata tags. DICOM files are organized hierarchically as follows:

  • Patient – A person or animal
  • Study – A group of related imaging procedures
  • Series – A single series of images, captured sequentially


How to View, Download, and Share DICOM Files?

DICOM files and images are generally saved with either a DCM30 (DICOM 3.0) or DCM file extension however, some may have no extension attributed. Stored DICOM files can be viewed using a DICOM Viewer. The process of retrieving, sending, and downloading files depends upon the design of the DICOM Viewer being used.

Functions of DICOM Viewer



The difference between PACS and DICOM is that PACS is a medical image storage and archive hub, fed by medical modalities such as X-ray scanners and MRI machines, while DICOM represents the international communication standard – not a device or structure – used by healthcare professionals in storing, processing, transmitting medical images and data.


Curious about the DICOM compliance of RamSoft’s products? View our conformity statement.


What is CIS?

A Clinical Information System (CIS) involves networked software solutions working together within a radiology practice such as a RIS and electronic health record system. Geared specifically towards clinical care usage (e.g., Intensive Care Units), a CIS is an information system networks with computer systems utilized in various departments present-day hospitals. These departments include cardiology, radiology, and pathology. A CIS gathers patient data and transfers it into an electronic record which an attending clinician can access while visiting the patient’s bedside.

Through the healthcare organizations are aptly supported in their operations, policy implementation, and patient data stewardship.


benefits of clinical information system


To understand why a CIS is an essential tool in the provision of optimal patient care, let’s examine how the ways it benefits both patient and clinicians. Leveraging a CIS enables:

  • Enhanced communication between the patient and their healthcare teams as well as among the healthcare professionals themselves
  • Comprehensive knowledge transference to ensure clinicians can make informed, sound decisions
  • The facilitation of easy patient access to x-ray and scans when required
  • Effective quality improvement of care administration and delivery
  • An open door to advanced clinical research


Note: ‘Clinicians’ refers to care givers providing direct care such as doctors and nurses. The term also incorporates therapists, clinical psychologists, endoscopists, clinical pharmacists, interventional radiologists, dietitians, optometrists, clinical microbiologists, audiologists, etc.

Since a CIS captures and processes all relevant medical information electronically, the need for paper-based documentation is reduced, data entry errors are diminished, ultimately resulting in considerable time (and cost!) savings for healthcare organizations. Thereby, providing positive impacts to the quality of patient care being delivered.

In Review

As with everything, all things must come to an end!

Throughout this blog, we have studied the definitions of the RIS, PACS, DICOM, and CIS systems as operating within the healthcare background. Plus, we reviewed some top benefits and advantages and use cases for each, while having delved into a pointedly focused difference between RIS, PACS, DICOM, and CIS.

Due to the inherent innovation built into each of these and other systems, many healthcare organizations experience superlative efficiency and operations with their workflows every day. This enhancement of the diagnostic and administrative processes has a direct correlating effect on enabling these organizations to responsively meet the needs of their patient base towards capably providing best-value, consistent care.

Whether just starting out in the healthcare sector or radiology field, setting up a new practice, or simply seeking to expand your knowledge on the various relevant management systems available in the medical arena, please feel free to use this blog as a convenient resource to refer to, if and when you need it.

Or…whether presently using RIS/PACS, PACS, or DICOM-centered radiology software solutions, consolidate them all and ensure your healthcare enterprise is set up to deliver faster, empowered, patient-centric care — ask us how the world’s first Imaging EMR, OmegaAI, can make it happen! Connecting to our team of experts is just a click awayreach out today.