What Is DICOM: Understanding Image Exchange in Radiology

Posted in AI Healthcare

What is DICOM in radiology? DICOM or Digital Imaging and Communications in Medicine is an international standard that specifies how medical images are produced, transmitted, stored, and displayed. This ensures seamless interoperability between different devices like scanners, servers, workstations, printers, PACS, etc. Before its widespread adoption, the process of image transmission was costly, time-consuming, and limited in accessibility. DICOM supports a wide range of imaging modalities, including X-rays, CT, MRI, ultrasound, nuclear medicine, and PET scans. Today, it facilitates over 98 billion medical images annually worldwide, resulting in faster, more accurate diagnoses. In the following sections, we will explore DICOM in detail, its role in radiology, components of a DICOM file type, and more.

How DICOM is Used in Radiology?

DICOM simplifies medical imaging by creating a digital standard for images and their associated data. It works as a universal language that allows different medical devices and systems to communicate.

Here’s how it’s used: 

1. Image Acquisition and Storage

After an imaging procedure like an X-ray, CT scan, or MRI is performed, the machine produces a DICOM file. Unlike a standard image file format like JPEG or PNG, a DICOM file contains two elements:

• The image data (the scan itself)

• Metadata in the header, which includes details such as:
  • Patient identifiers (ID, name, date of birth).
    
  • Study information (exam type, date, and time).
    
  • Imaging parameters (exposure settings, equipment details).
    
  • Anatomical orientation.
    

This combination guarantees that images are never separated from the clinical context needed for accurate diagnosis. 

Typically, these files are stored in a PACS system (Picture Archiving and Communication System), which functions as a digital repository and makes retrieval and management significantly easier than traditional film archives.

2. Transmission and Sharing

A DICOM system supports secure and efficient data transmission. The standard establishes communication protocols that enable:

• Transfer from scanner to PACS: The imaging device automatically sends files to long-term storage.
  
• Access for diagnosis: Clinicians can view images from any DICOM-compliant workstation, regardless of the manufacturer.
  
• Teleradiology and collaboration: Images can be securely shared with specialists across locations, enabling faster second opinions and expanding access to expertise.
  

3. Printing and Display

• DICOM also defines protocols for printing and displaying images for consistency in quality across devices. 
• Whether images are printed on film for traditional workflows or displayed on diagnostic monitors, the standard guarantees that resolution, contrast, and orientation are preserved. 
• This consistency is essential for accurate clinical interpretation and helps organizations maintain compliance with regulatory standards.

Why DICOM is Important in Radiology?

DICOM ensures interoperability between different imaging devices, such as MRI and CT scanners, and the PACS systems that store them. 

Seamless Communication

DICOM creates a common language for imaging devices from different manufacturers. Without this standard, each device would produce data in its own format, making it difficult to share or interpret images across platforms. 

DICOM solves this problem by ensuring that all compliant equipment can communicate seamlessly, forming the backbone of modern imaging systems.

PACS Integration

DICOM integrates with Picture Archiving and Communication Systems (PACS). These systems are essential for storing, retrieving, and managing medical images. 

Because DICOM ensures compatibility across devices, radiology teams can consolidate images from multiple modalities into a single repository, simplifying workflows and reducing errors via healthcare integration.

Standardized Data

By standardizing both image data and metadata, DICOM makes it easier for healthcare organizations to manage, store, and distribute medical images. 

This eliminates the challenges of dealing with proprietary formats and enables consistent practices across entire networks.

Easy Access

With DICOM, clinicians can quickly query and retrieve images using patient identifiers or study details. 

This reduces the time spent searching for specific images, streamlines reporting, and allows radiologists to focus more on interpretation rather than administrative tasks. 

High-Quality Images

DICOM ensures that images retain the necessary resolution and detail required for accurate diagnoses. 

Unlike compressed consumer image formats, the protocol preserves the integrity of clinical scans, allowing radiologists to rely on consistent image quality across systems.

Image Manipulation and Analysis

Beyond storage, DICOM supports advanced diagnostic functions through specialized viewers. These tools allow clinicians to adjust brightness, contrast, and zoom levels to highlight areas of concern. 

Additionally, DICOM supports multiplanar reconstruction (MPR), enabling the creation of 3D views from 2D images, an essential capability in modern radiology.

Data Security

Protecting sensitive patient information is a critical priority in healthcare. DICOM includes built-in security features such as encryption, digital signatures, and access controls. 

These safeguards ensure that images and associated data remain protected both during transmission and while stored in archives.

Audit Trail

The standard also supports audit trail functionality, which records data access and changes over time. 

This provides transparency, enhances accountability, and helps healthcare organizations meet regulatory compliance requirements.

Long-Term Data Access

DICOM ensures that imaging data can be stored and retrieved for years after the initial scan. 

This long-term accessibility is vital for follow-up care, comparative analysis, and building a comprehensive patient imaging history.

Core Components of the DICOM Standard

The DICOM standard is meticulously defined across several parts, which together form its robust architecture.

The DICOM Object: It is the most fundamental part; unlike a simple JPEG or PNG, a DICOM file combines image pixel data with an extensive, standardized metadata header. 

This header contains essential attributes, such as patient demographics, study details (e.g., date and time of scan), and technical parameters of the imaging equipment. This rich metadata is crucial for clinical context, ensuring that an image is never separated from its relevant information.

The Communication Protocol: The standard specifies a network protocol built on TCP/IP that governs how devices interact. This is where the concept of Service-Object Pair (SOP) Classes comes into play. 

For instance, the DICOM Store SOP Class allows a CT scanner to send images to an archive, while the DICOM Query/Retrieve SOP Class enables a radiologist’s workstation to search for and retrieve a patient’s images from a Picture Archiving and Communication System (PACS).

Conformance and Interoperability: A key part of the standard is the DICOM Conformance Statement. Every DICOM-compliant product must have one, detailing the specific SOP classes and capabilities it supports. 

This document is a critical tool for healthcare IT departments, allowing them to verify that different systems will be able to communicate effectively before procurement.

What is the Image Format in DICOM?

DICOM files are in “.dcm” format, designed specifically for healthcare, and include not only the pixel data that forms the medical image but also a structured set of metadata that provides critical context. 

This design allows the image to remain inseparably linked with the patient information, imaging parameters, and study details needed for clinical use.

DICOM is compatible with virtually every imaging modality in medicine, including X-ray, CT, MRI, ultrasound, nuclear medicine, PET, and digital pathology. By preserving both the image and its associated details together, DICOM ensures that medical data can be accurately interpreted, shared, and archived without risk of losing essential context.

What are the Parts of a DICOM File?

A DICOM file is composed of three key elements:

• Header (Metadata): Contains structured information such as patient demographics, exam type, acquisition parameters, referring physician, and anatomical orientation.
  
• Dataset (Image Data): Holds the pixel values that represent the image itself, which can be single-frame (like a chest X-ray) or multi-frame (like a dynamic ultrasound or MRI sequence).
  
• Service-Object Pair (SOP) Classes: Define the specific type of medical object and the operations that can be performed on it. Examples include CT Image Storage, MR Image Storage, and Ultrasound Image Storage.
  

Various DICOM Protocols

The following protocols ensure that imaging workflows remain standardized, secure, and efficient.

• Network Image Management: Defines how images are securely transmitted from imaging devices to PACS or between healthcare facilities. It ensures that images arrive intact, complete, and associated with the correct metadata.
  
• Network Image Interpretation Management: Supports the sharing of interpretation data and structured reports, allowing radiologists and other clinicians to collaborate more effectively. This protocol enables results to travel with the images, improving communication between providers.
  
• Network Print Management: Provides the ability to print medical images in high resolution for physical records, patient consultations, or archival purposes. Although film is less common today, print management remains useful in certain workflows.
  
• Imaging Procedure Management: Governs the scheduling, execution, and documentation of imaging procedures, ensuring consistency in how imaging studies are requested, performed, and logged in hospital systems.

DICOM Workflow Process

How Different Teams Access DICOM Files

With DICOM serving as a unified standard, all stakeholders in the healthcare system can interact with medical images consistently and reliably. 

Radiologists On-Site

Radiologists access DICOM files directly through PACS imaging systems and diagnostic workstations. This workflow is pivotal to the radiology practice, as it allows clinicians to review and compare studies for accurate diagnosis and treatment planning. 

Radiology teams may rely on either on-site PACS solutions, which keep data within the hospital’s IT infrastructure, or cloud-based PACS platforms, which provide scalable access across multiple locations and support remote reading. 

Referring Physicians and Specialists

Outside of the radiology department, referring physicians and specialists often need to access imaging results to guide treatment decisions. DICOM files are typically delivered in a simplified viewing format through electronic health records (EHR) systems, web viewers, or shared PACS access. 

This integration ensures that imaging data is readily available to surgeons, oncologists, cardiologists, and other providers who rely on radiology insights for patient care.

Patients

Patients most often access their DICOM files through patient portals provided by hospitals or imaging centers, or through physical media such as CDs, DVDs, or USB drives. 

This access gives patients more control over their health information and enables them to share their medical images with new providers, specialists, or second-opinion services. Increasingly, healthcare organizations are adopting secure, cloud-based portals that allow patients to download and share DICOM studies digitally, reducing the reliance on outdated physical media.

AI-Imaging Solution – PACScribe – by Folio3 Digital Health

Folio3 Digital Health’s PACScribe is an AI-powered medical imaging solution that improves diagnostic accuracy with the help of advanced AI algorithms. During our medical imaging software development, we not only build solutions that analyze images with speed and precision but also generate automated reports to assist clinicians in decision-making. 

Our solution, PACScribe, ensures HIPAA compliance and supports seamless interoperability with existing healthcare systems through industry standards such as DICOM and HL7 integration. By enabling secure storage, transmission, and retrieval of DICOM files, the platform fits naturally into the imaging workflows that radiologists and healthcare teams rely on every day. 

How PACScribe Uses DICOM

Interoperability

PACScribe supports the DICOM standard, which allows it to connect with imaging equipment from multiple vendors without compatibility issues. 

CT, MRI, ultrasound, and X-ray studies are all stored and accessed in the same system, removing the need for manual conversions or multiple viewers. This ensures that every clinician is working with the same data in one unified platform.

Workflow Efficiency

PACScribe standardizes the intake and distribution of DICOM studies and eliminates the delays that often occur when retrieving or transferring imaging files between systems. 

A radiologist can instantly query a patient’s DICOM record using ID or study date and pull up the complete set of images in seconds, rather than relying on physical media or siloed archives. This directly shortens report turnaround times and speeds up clinical decision-making.

AI-Enhanced Analysis

PACScribe integrates AI models that are trained on DICOM imaging datasets to detect specific abnormalities such as lung nodules, brain lesions, or bone fractures. 

When a study is uploaded, the AI can pre-analyze the DICOM images, highlight areas of concern, and even generate structured findings. This assists radiologists by reducing oversight risk and enabling faster, more confident reporting.

Secure Compliance

Because DICOM imaging includes encryption and digital signature capabilities, PACScribe leverages these alongside HIPAA-compliant workflows to protect patient information. 

All DICOM files are transmitted over secure channels, access is role-based, and audit trails log every interaction with an image. 

Closing Note

DICOM is the foundation of modern medical imaging that standardizes the format and communication protocols. It ensures that radiologists, physicians, and patients alike can rely on seamless interoperability, high-quality diagnostics, and secure access to imaging data. As imaging volumes continue to grow and healthcare organizations demand greater efficiency, the importance of DICOM imaging will only deepen.

For providers looking to maximize the value of this standard, platforms like PACScribe by Folio3 Digital Health demonstrate how DICOM ultrasound can be leveraged in practice, delivering interoperability, workflow efficiency, AI-powered insights, and secure scalability. With the right solution in place, DICOM is not just a standard; it is a strategic enabler for better care, stronger collaboration, and future-ready healthcare delivery.

Frequently Asked Questions 

What does DICOM stand for?

DICOM stands for Digital Imaging and Communications in Medicine.

What is a DICOM file?

A DICOM file is a standardized, comprehensive digital format for medical images like X-rays, CT scans, and MRIs, containing both the image data and metadata such as patient information, acquisition details, and diagnostic notes. 

What is a DICOM viewer?

A DICOM viewer is specialized software used to open, view, and analyze medical images like MRIs, CT scans, and X-rays. Unlike standard image viewers, it can handle the complex DICOM file format, which includes not only the image data but also critical patient and study information. 

What is DICOM used for?

It is the international standard for the secure and efficient management of medical imaging data. This allows for the reliable transmission of imaging studies from a diagnostic modality (like an MRI or CT scanner) to a PACS System to a workstation for physician analysis, and to other healthcare information systems for integration with patient records.

What types of images use the DICOM standard?

DICOM is the standard for almost every type of medical image produced today, including:

• X-rays
• Computed Tomography (CT) scans
• Magnetic Resonance Imaging (MRI)
• Ultrasound
• Nuclear Medicine
• Positron Emission Tomography (PET)
• Mammography

Can a DICOM file open on a regular computer?

No. A DICOM file needs a specialized DICOM viewer software or PACS system like PACScribe by Folio3. Many of these viewers are available for free and are designed to not only display the image but also read the metadata and allow for advanced functions like measuring distances, adjusting brightness, and viewing multi-frame studies.

What is the difference between DICOM and PACS?

• DICOM is the file format and the communication rules.
• PACS (Picture Archiving and Communication System) is the centralized server system that uses the DICOM rules to manage, store, and distribute all of a hospital’s images.

DICOM is the foundation; PACS is the complete system built upon that foundation.

What is DICOM format?

A DICOM file is a special type of data container. Unlike a simple image file like a JPEG, it bundles two crucial components:

• Image Data: The actual pixel information that makes up the medical image (e.g., an X-ray, MRI, or CT scan).
• Metadata: A detailed header that contains information about the patient (name, ID, date of birth), the study (type of scan, date, time), and the equipment used. This ensures that the image is always linked to its correct clinical context.

What is the DICOM file type?

The most common file extension for a DICOM file is .dcm.

However, it’s also important to know that many DICOM files, particularly when they are on a CD or DVD for a patient, have no file extension at all. This is a common practice and is part of the DICOM standard for media storage.

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