DICOM Attribute

Pixel Spacing (0028,0030)

Keyword
PixelSpacing
VR
DS
VM
2

Definition

Physical distance in the patient between the center of each pixel, specified by a numeric pair - adjacent row spacing (delimiter) adjacent column spacing in mm. See for further explanation.

From NEMA PS3.3 §C.7.6.2.

Attribute Metadata

Tag
(0028,0030)
Keyword
PixelSpacing
Name
Pixel Spacing
Value Representation (VR)
DS
Value Multiplicity (VM)
2
Status
Active
Source
NEMA PS3.6 (table_6-1)

This attribute is part of the current DICOM Standard. Its value representation is DS with multiplicity 2.

Used in 7 Modules

This attribute uses the DS Value Representation. Multiplicity 2 governs how many values may be encoded.

Integration Notes

Real-world integration guidance for engineers implementing this attribute in Mirth Connect, FHIR gateways, HL7 v2 bridges, and cloud DICOM services. Authoritative source data where available; reference examples and operational notes where they add value.

FHIR Mapping

No direct FHIR ImagingStudy mapping published for this attribute. Some tags map indirectly via the Patient, Endpoint, or ImagingSelection resources — Phase 2b will expand coverage to those.

HL7 v2 Equivalent

No standard HL7 v2 equivalent published for this attribute. Imaging-only attributes (Image Pixel data, technical acquisition parameters, modality-specific values) typically have no HL7 v2 carrier.

Cloud DICOM Support

  • AWS HealthImaging Preserved
  • Azure DICOM Preserved
  • Google Cloud Healthcare Preserved

Pixel Spacing — preserved by all three. Critical for measurement accuracy in imaging viewers.

Per-vendor source URLs and verification date in src/content/dicom/cloud-support.json#_meta. Status taxonomy: required (mandated on Store), queryable (QIDO-RS matching key), preserved (stored as-is), promoted (AWS top-level metadata), unsupported (stripped/rejected).

Real-World Sample Values

  • 0.661468\0.661468 CT_small.dcm
  • 0.3125\0.3125 MR_small.dcm
  • 10.0000000000000\10.0000000000000 rtdose.dcm

Extracted from pydicom test fixtures (MIT, de-identified).

Mirth Connect Example

Extract Pixel Spacing for measurement-aware downstream — PixelSpacing (DS \\ DS, mm) drives quantitative measurements

PixelSpacing (DS \\ DS, mm) drives quantitative measurements. Convert to a per-axis float pair and stash in channelMap for downstream FHIR enrichment.

// (0028,0030) Pixel Spacing — multi-value DS
var ps = String(msg.dataset.attr.(@tag == '00280030').value).split('\\');
var rowSpacing = parseFloat(ps[0]);
var colSpacing = parseFloat(ps[1]);
if (!isNaN(rowSpacing) && !isNaN(colSpacing)) {
  channelMap.put('pixel_spacing_row', rowSpacing.toFixed(6));
  channelMap.put('pixel_spacing_col', colSpacing.toFixed(6));
}

Reference only — validate before production. Snippets are starting points, not turnkey solutions. Always test against your channel's specific message structure and your facility's interface specification. See Mirth Connect User Guide + NEMA PS3.6 + your vendor conformance statement for authoritative specification.

Common Operational Errors

  • medium Pixel Spacing reversed (col,row vs row,col)

    Diagnosis: DICOM PS3.3 mandates row-spacing first, column-spacing second. Some legacy modalities reverse the order, causing measurements in viewers to be off by the spacing ratio.

    Fix: Cross-check with (0028,0011) Columns vs (0028,0010) Rows — for non-square pixels, Pixel Spacing values should track. If suspiciously reversed: contact modality vendor for firmware patch; in the interim, swap on perimeter.

Reference only — validate before applying a fix. Scenarios are drawn from common DICOM/HL7 v2 integration patterns; reproduce against your environment before acting on any diagnosis. See NEMA PS3.6 + your vendor conformance statement for authoritative specification. Severity levels: high (data-loss / patient-safety), medium (workflow disruption), low (cosmetic).

DICOM Integration Services

Saga IT builds production DICOM integrations across Mirth Connect, FHIR gateways, and cloud imaging platforms. If you're working with PixelSpacing or the broader (0028,0030) context: