🧐What is the difference between DICOM and NIfTI medical image formats

Before we look at the differences between DICOM and NIfTI, let's take a closer look at what each of these formats is individually

🤔What is the DICOM standard?

The DICOM standard — Digital Imaging and Communications in Medicine (DICOM) — is used to exchange images and information, it has been popular for more than a decade. Today, almost every device used in radiology (including CT, MRI, ultrasound and radiography) is equipped with support for the DICOM standard. According to the information from the standard developer (), DICOM allows you to transfer medical images in an environment of devices from different manufacturers and simplify the development and expansion of image archiving and communication systems.

🤔What is the NIfTI standard?

The Neuroimaging Informatics Technology Initiative (NIfTI) was created to work with users and manufacturers of medical devices to address some of the problems and shortcomings of other imaging standards. NIfTI was specifically designed to address these issues in the field of neuroimaging, with a focus on functional magnetic resonance imaging (fMRI). According to the NIfTI definition, the primary mission of NIfTI is to provide coordinated, targeted services, education, and research to accelerate the development and usability of neuroimaging informatics tools. NIfTI consists of two standards, NIfTI-1 and NIfTI-2, the latter being a 64-bit enhancement of the former. It does not replace NIfTI-1, but is used in parallel and supported by a wide range of medical neuroimaging devices and operating systems.

❓What is the difference between DICOM and NIfTI?

1. NIfTI files have less metadata: An NIfTI file does not require as many tags to be filled in as a DICOM image file. There is much less metadata to inspect and analyze, but this is in some ways a disadvantage because DICOM provides users with different layers of image and patient data.

2. DICOM files are often bulkier: DICOM data transfer is governed by strict formatting rules that ensure that the receiving device supports SOP classes and transfer syntaxes, such as the file format and encryption used to transfer the data. When transferring DICOM files, one device talks to another. If one device cannot process the information that the other is trying to send, it will inform the requesting device so that the sender can roll back to a different object (e.g. a previous version) or send the information to a different receiving end. Therefore, NIfTI files are usually easier and faster to process, transfer, read, and write than DICOM image files.

3. DICOM works with 2D layers, while NIfTI can display 3D details: NIfTI files store images and other data in a 3D format. It is specifically designed to overcome the spatial orientation issues of other medical imaging file formats. DICOM image files and associated data are made up of 2D layers. This allows for viewing different sections of an image, which is especially useful when analyzing the human body and different organs. However, with NIfTI, neurosurgeons can quickly identify objects in images in 3D, such as the right and left hemispheres of the brain. This is invaluable when analyzing images of the human brain, which is extremely difficult to evaluate and annotate.

4. DICOM files can store more information: As mentioned above, DICOM files allow medical professionals to store more information in different layers. Structured reports can be created and even images can be frozen so that other clinicians and data scientists can clearly see what the opinion/recommendation is based on.