What is DICOM? Everything you should know

Probably every person who has had the opportunity to use radiological equipment has met the DICOM term. This certainly applies to patients who have undergone a CT scan or magnetic resonance imaging. What exactly is this acronym?

What does DICOM stand for?

DICOM stands for Digital Imaging and Communications in Medicine, which translates as “digital imaging and image exchange in medicine”. Generally speaking, DICOM is a standardized method of recording medical image data that can be read on any medical device.

How were DICOM files developed?

The DICOM format was developed by the National Electrical Manufacturers Association (NEMA) in collaboration with the American College of Radiology (ACR) out of the need to create a method that would allow one test to be read across multiple devices. Before its creation, a common problem in the medical community was the difficult interpretation of test results, which depended on the hardware manufacturers' recommendations.

The test results were, and still are, one of the main factors influencing treatment decisions, e.g., the selection of the radiation dose. A distorted reading of the data could contribute to complications. In addition, standard graphic formats (e.g., JPG) did not make it possible to collect all information about both the examination itself and the patient. Therefore, it was necessary to develop a standard that would allow for the greatest possible precision.

Work on this method has been carried out since the 1980s. It was completed successfully in 1992 — since then it has been called DICOM and has been constantly developed.

What are the advantages of DICOM?

Thanks to the standardization of the method of data recording, it is possible to read it by any medical equipment, also from different manufacturers. Thanks to this, the results of tests carried out by computer tomography or magnetic resonance, can be read and analyzed within a single diagnostic station. Such a facility significantly reduces costs, limiting the hardware requirements to the necessary minimum.

Standardization of communication between devices also makes it possible to create transmission and archiving systems for image data. These systems are known as PACS (Picture Archiving and Communication). In addition, the DICOM standard has been developed with the use of the web in mind, making teleradiology development possible.

How are JPEG files different from DICOM files?

JPEG files contain a single image — monochrome or color. Moreover, their size is relatively small. It’s completely different in the case of DICOM files. This format was created not only to store a large number of images obtained during imaging tests, but also data, e.g., about patients. Thanks to this format, efficient communication between various medical units is possible with the use of a single set of inseparably interconnected data. DICOM files are characterized by a large volume, therefore they require special software and appropriate computer hardware.

Where are DICOM files used?

DICOM is most common in the case of imaging tests such as:

• computed tomography (CT),
• magnetic resonance imaging (MRI),
• positron emission tomography (PET).

They are used for storing and transmitting medical images. Thanks to the standardization of files, it is possible to integrate not only devices intended for taking diagnostic images, but also enables efficient data exchange between scanners, servers, workstations, network equipment and various types of archiving systems.

DICOM files are also used when the test result is exported to an external medium, such as a CD / DVD. Currently, after the test is performed, each patient receives a CD / DVD with the results saved in the DICOM format for their own use. On such a disc, you can find a dozen folders containing all the necessary data. Such data may also be transferred for analysis to another specialist.

Reading DICOM files at home

Due to the nature of DICOM files, they cannot be displayed in a given operating system (e.g. Windows) in the traditional way, by double-clicking. To view them, you must have dedicated software — the DICOM file viewer. Therefore, you can often find an installation file for such a program on the test disc that you receive from your medical facility. Thanks to this, the patient can see the results of the imaging test at home.

DICOM files and 3D visualizations in medicine

DICOM files may also be used for other purposes. One of the possibilities is 3D visualization. A very large number of images taken during the examination allows them to be superimposed on each other and then generate the image in three dimensions.

To perform such a visualization, software designed to create medical images in 3D is necessary. The resulting image provides an insight, not into the general anatomical model, but into the patient's own organism. This is important, especially due to the fact that each human's anatomical proportions are different. The same disease entities that occur in different patients also differ from each other.

The visualization of the patient's body, created on the basis of 3D technology, also gives the possibility of manipulating the image — rotating, zooming in, zooming out, modifying the contrast and exposing the most important layers. Due to these properties, visualizations are more and more often referred to as an opportunity to perform even more precise surgical procedures.