Medical Image Compression Guide

Why Compress Medical Images?

Medical imaging produces large volumes of data that require significant storage space and bandwidth. Compression helps reduce storage costs, improve transmission speeds, and maintain efficient PACS operations while preserving diagnostic quality.

Lossless vs Lossy Compression

  • Lossless Compression: No data loss, perfect reconstruction
  • Lossy Compression: Some data loss, smaller file sizes
  • Visually Lossless: Appears lossless to human observers
  • Diagnostically Lossless: No loss of diagnostically relevant information

Compression Methods

JPEG

Common lossy compression suitable for many diagnostic applications with proper quality settings

10:1 to 20:1

JPEG-LS

Lossless/near-lossless compression specifically designed for medical images

2:1 to 3:1

JPEG 2000

Wavelet-based compression offering both lossless and lossy options with better quality

5:1 to 50:1

RLE

Run-Length Encoding, simple lossless compression for images with large uniform areas

1.5:1 to 3:1

Compression Ratio Guidelines

Modality Lossless Ratio Acceptable Lossy Ratio Recommended Method
CT Scan 2:1 - 3:1 10:1 - 15:1 JPEG 2000
MRI 2:1 - 4:1 8:1 - 12:1 JPEG-LS
X-Ray/CR/DR 2:1 - 3:1 15:1 - 20:1 JPEG
Ultrasound 1.5:1 - 2:1 10:1 - 15:1 JPEG 2000
Mammography 2:1 - 3:1 5:1 - 8:1 Lossless only

Important Considerations

Clinical Validation Required: Always validate compression settings for your specific clinical use case and ensure they meet regulatory requirements.
  • Always maintain diagnostic image quality
  • Consider legal and regulatory requirements
  • Test compression with various image types
  • Document compression methods and ratios used
  • Consider future AI/ML analysis needs

Storage Savings Calculator

Use our DICOM PACS Storage Calculator to estimate the impact of different compression ratios on your storage requirements. The calculator considers:

  • Daily study volume
  • Images per study
  • Average image size
  • Compression ratios
  • Retention periods
  • Growth projections
Open Storage Calculator