In DICOM, KO stands for Key Object Selection. It is a specific modality value used to identify a DICOM object that represents a collection of "key" objects (images, series, or other DICOM instances) from a study or examination.
Understanding Key Object Selection (KO)
The DICOM standard defines various modality codes to categorize the type of equipment or process that generated imaging data. While many modalities like CT (Computed Tomography) or MR (Magnetic Resonance) refer to image acquisition devices, "Key Object Selection" (KO) is distinct. It does not refer to an imaging device itself but rather to a post-acquisition process of curating and highlighting significant information within a DICOM study.
The primary purpose of a DICOM Key Object Selection object is to:
- Identify critical findings: Radiologists or referring physicians can mark specific images or series that are most relevant for diagnosis, reporting, or follow-up.
- Streamline workflows: Instead of reviewing an entire large study, users can quickly jump to the highlighted "key" objects.
- Facilitate communication: It allows for easy sharing of pertinent images with colleagues, referring physicians, or for multidisciplinary team meetings.
- Support teaching and research: Key images can be compiled into teaching files or datasets for educational purposes.
Modality Codes in DICOM
The DICOM standard utilizes specific codes to classify the source or nature of the medical data. Here's how KO fits within this system:
| Value | Description |
|---|---|
| KO | Key Object Selection |
| LEN | Lensometry |
| LP | Laparoscopy |
| LS | Laser Surface Scan |
| CT | Computed Tomography |
| MR | Magnetic Resonance |
| US | Ultrasound |
Source: DICOM Modality
How KO Works in Practice
A Key Object Selection object is essentially a structured document within the DICOM ecosystem. It contains references (pointers) to other DICOM instances (images, structured reports, etc.) that are considered important.
For example:
- A radiologist reviews a CT scan with hundreds of images.
- They identify a few critical images showing a specific pathology.
- Using their PACS (Picture Archiving and Communication System) workstation, they can "mark" these images as key objects.
- The system then creates a DICOM Key Object Selection (KO) instance that links to these specific images.
- When another clinician opens the patient's study, they can immediately see the "KO" object, which, when opened, will present only the pre-selected critical images.
This functionality significantly improves the efficiency of image review and clinical decision-making by focusing attention on the most relevant information.
