If you're looking to modernise your hospital's imaging network, you've likely run into three terms that are constantly confused: PACS, VNA and MACS.
While they all handle medical media, they represent very different technological eras. Understanding the differences is the key to choosing an architecture that future-proofs your enterprise.
Comparison at a glance
| Feature | PACS | VNA | MACS |
|---|---|---|---|
| Primary scope | Single department (typically radiology) | Enterprise-wide storage layer | Entire hospital, all clinical and surgical specialties |
| Content types | Standard DICOM images (e.g. CT, MRI) | Standardised DICOM and wrapped non-DICOM files | Native DICOM & non-DICOM (photos, videos, PDFs, ECGs, EEGs) |
| Core value | High-performance diagnostic interpretation | Consolidation of multi-departmental storage | A single, patient-centric “multimedia medical dossier” |
1. PACS: the departmental specialist
A PACS is designed to manage, archive and display images for a specific department (usually radiology or cardiology). It is highly optimised for diagnostic reading but operates in a silo: built strictly around the DICOM standard, it cannot easily ingest or display files from non-radiology specialties.
2. VNA: the enterprise storage layer
A VNA is a storage strategy, not a clinical workflow tool. It decouples the viewing application from the long-term archiving layer. By storing data in open, non-proprietary formats, a VNA lets hospitals consolidate storage from multiple departmental PACS — ensuring data reversibility, making future migrations easier and avoiding vendor lock-in.
The limitation? A VNA is typically a “cold”, passive archive. It stores the data but doesn't provide the clinical viewers, capture tools or workflows that doctors need at the bedside.
3. MACS: the unified patient multimedia record
A MACS is the next generation of enterprise imaging — often described as “the multimedia arm of the electronic medical record (EMR)”. It extends high-performance imaging workflows across every specialty in the hospital, including digital pathology, dermatology, ophthalmology, endoscopy and the operating theatre.
A MACS manages the wealth of clinical media a traditional radiology PACS and VNA cannot — natively, and filed against the patient's record:
Native DICOM RT support — RT STRUCT, RT PLAN, RT DOSE and RT IMAGE — with TPS interoperability (Eclipse, Pinnacle, Dosigray) and direct Dose-Volume Histogram (DVH) computation.
Advanced PET-CT and SPECT-CT fusion with precise SUV (Standardised Uptake Value) calculations and rotating 3D MIP views to track tumour evolution over time.
Bedside smartphone capture via TM-Capture, sent straight to the patient record — dermatology, pressure-ulcer and wound tracking, pre/post-op comparisons, and forensic/emergency documentation.
ECG PDFs auto-linked to the patient folder (plus photos of legacy paper traces), and EEG tracings in standard or proprietary formats.
Endoscopy sequences (AVI, MPEG, MP4) with sub-sequence selection, “surgeon's selection” labelling and snapshot-to-key-image indexing.
Whole-slide imaging in vendor-neutral or proprietary formats (Hamamatsu, 3DHistech), plus high-resolution macroscopic photography.
Fundus (retinal) JPEGs and structured PDF reports — visual fields (Humphrey), Pentacam cornea maps, Retcam and OCT.
Scanned PDFs of patient-signed consent forms, clinical questionnaires and custom structured diagnostic reports.