Horos Software |link|

Horos is a free, open-source medical imaging software specifically designed for macOS, serving as a powerful workstation for radiologists and medical researchers to view and manipulate DICOM (Digital Imaging and Communications in Medicine) files. Key Features and Capabilities

Horos provides a comprehensive set of tools for medical data visualization:

Multi-Dimensional Viewing: Offers high-resolution 2D viewing along with advanced 3D volumetric rendering and 3D reconstruction.

ROI (Region of Interest) Tools: Includes precise tools like the "Closed Polygon Tool" and "ROI compute" for segmenting tumors or calculating the volume of hematomas.

Data Management: Supports importing and exporting DICOM files, query and auto-retrieve functions, and DICOM auto-routing.

Image Redaction: Allows users to redact sensitive patient information by setting pixel values to zero within a selected area, which is essential for research submissions. Common Applications

Horos is widely used in both clinical and research settings: Horos Project: Home Page

Understanding Horos: The Powerful Open-Source Medical Image Viewer

In the rapidly evolving field of medical imaging, having reliable, accessible, and high-performance software is critical for clinicians, researchers, and students. Horos has emerged as a premier open-source solution, providing advanced tools for viewing and analyzing medical images across various specialties. What is Horos Software?

Horos is a free, open-source medical image viewer based on OsiriX, a well-known DICOM (Digital Imaging and Communications in Medicine) viewer for macOS. Distributed under the GNU Lesser General Public License (LGPL) version 3.0, Horos offers a familiar interface and robust feature set without the high costs typically associated with proprietary medical imaging software. horos software

It is designed to run exclusively on macOS, leveraging the operating system’s powerful graphics and processing capabilities to handle complex three-dimensional datasets. Key Features and Capabilities

Horos is more than just a viewer; it is a comprehensive diagnostic and research tool. Some of its most notable features include:

Multiplanar Reconstruction (MPR): Allows users to view anatomical structures from axial, coronal, and sagittal perspectives simultaneously.

3D Volume Rendering: Transforms 2D image slices into detailed three-dimensional models, which is essential for understanding complex spatial relationships in surgical planning.

Volumetric Analysis: Facilitates precise measurement of volumes, such as determining the residual volume of tumors after surgical resection.

Region of Interest (ROI) Tools: Enables manual or semi-automatic segmentation of specific tissues or vessels for detailed quantitative analysis.

Surgical Simulation: Supports virtual preoperative planning by allowing clinicians to simulate surgical stages and identify local vascular patterns. Practical Applications in Modern Medicine

Horos has found extensive use across various medical disciplines due to its versatility: Video Case Series of Postoperative Tumor Analyses - PMC

Here’s a concise guide to getting started with Horos, a free, open-source medical image viewer for macOS (based on OsiriX). Horos is a free, open-source medical imaging software

Alternatives (examples)

OsiriX (commercial / paid Pro version for macOS)
RadiAnt DICOM Viewer (Windows)
3D Slicer (cross-platform, research-focused)
Weasis (cross-platform, open-source)

Horos Software — Overview & Key Details

What it is Horos is an open-source medical image viewer for macOS that supports DICOM standards. It’s designed for clinicians, radiologists, and researchers to view, analyze, and manage medical imaging studies (CT, MRI, ultrasound, PET, etc.).

5. Database and Network Features

Local Database: Organize thousands of studies on a local hard drive.
DICOM Query/Retrieve (C-FIND, C-MOVE): Pull studies directly from PACS (Picture Archiving and Communication System) over the hospital network.
Web Access: Horos can act as a web server, allowing other devices on the same network to view images via a browser.

1. Native DICOM Support

Horos reads and displays all standard DICOM files, including CT, MRI, PET, ultrasound, and digital radiography. It handles multi-frame images, 3D volumes, and even 4D time-series data with ease.

Limitations of Horos Software

No tool is perfect. Before downloading, consider these drawbacks:

macOS Only – If your institution uses Windows or Linux, Horos is not an option.
No FDA Clearance (Free Version) – You cannot legally use the free Horos for primary clinical diagnosis in the US. You must purchase Horos MD.
Performance on Older Macs – Heavy 3D rendering requires a fairly modern Mac with a dedicated GPU (or recent Apple Silicon).
DICOM RT (Radiotherapy) Limitations – While basic RT structure sets work, advanced dose-volume histogram (DVH) analysis is better done in dedicated software.
Community Support Only – The free version has no official support; you rely on user forums.

3. Measurement Tools

Precise ROI (Region of Interest) tools including:

Length, angle, and area.
Volume calculations.
SUV (Standardized Uptake Value) measurements for PET/CT.

Conclusion: Should You Use Horos Software?

Yes, if:

You are on a Mac.
You need a fast, intuitive, and powerful DICOM viewer for non-diagnostic work.
You are a student, researcher, or veterinarian.
You want to avoid paying $1,000+ for OsiriX.

No, if:

You are a US radiologist making formal patient diagnoses.
You need Windows or Linux compatibility.
You require guaranteed technical support or FDA clearance.

Horos software democratizes medical imaging. It puts a $50,000 imaging workstation into the hands of anyone with a MacBook. Whether you are a vet saving a Golden Retriever’s life, a researcher quantifying tumor size for a cure, or a patient trying to understand your own anatomy, Horos is an indispensable, world-class tool that costs absolutely nothing.

Disclaimer: This article is for informational purposes only. Consult a qualified physician for medical diagnosis. Always confirm that software use complies with local medical device regulations.

Horos is a free, open-source medical imaging software primarily used as a DICOM viewer for macOS. It was developed based on the open-source version of OsiriX (specifically version 5.8) after that software transitioned to a more restrictive commercial model. Key Features and Use Cases Alternatives (examples)

Medical Image Viewing: It allows clinicians and researchers to view and manipulate images from various modalities, including CT, MRI, PET-CT, and Ultrasound.

3D Reconstruction: Horos is widely used for 3D volumetric rendering, which helps surgeons simulate operative trajectories and plan complex procedures like craniotomies or tumor removals.

Research and Deep Learning: Researchers use it to annotate and label medical datasets—such as CT-angiograms for pulmonary embolism—to train deep learning models.

Forensic and Anatomical Analysis: It is used in specialized fields for tasks like measuring facial soft tissue thickness in forensic reconstructions or analyzing genetic mouse models for congenital heart disease. Critical Considerations

Platform Specificity: Horos is designed strictly for 64-bit macOS systems.

Regulatory Status: While functionally powerful, it is often noted that Horos does not have FDA or CE Marking for diagnostic use. As a result, it is frequently used for research, teaching, or as a secondary tool rather than the primary diagnostic workstation in some regulated medical environments.

The project is hosted and maintained by the Horos Project, which also provides a comprehensive user guide and educational resources through the Horos Academy.

Horos is a free, open-source 64-bit DICOM medical image viewer designed exclusively for macOS, offering advanced 2D and 3D viewing capabilities. As a community-driven alternative to OsiriX, it is widely utilized for research and education, although it is not FDA-certified for primary diagnosis. Read more at Horos Project Blog. Our Mission - Horos Project