Table 2:

Mixed-density and hypodense SDCs—2 typical problem constellations during the initial CT investigationa

CT FindingDifferential DiagnosisPathophysiologyForensic Relevance
Heterogeneous hypo- and hyperdense SDC (mixed-density pattern)
1) Hyperacute + acute SDHUnclotted and clotted bloodCompatible with 1 hemorrhagic event
Assumed EoA: 0–24 hr
2) Acute SDHCompacted clot with serum separationCompatible with 1 hemorrhagic event
Assumed EoA: 1–3 days
3) SDHHy“Acute blood” and CSF, eg, due to BV injury and concomitant arachnoid tearCompatible with 1 hemorrhagic event
Assumed EoA: 1 day–min 1 wk
4) Acute + chronic SDHAcute hemorrhage within a pre-existing cSDH/SDHyCompatible with 2 (or more) hemorrhagic events
Assumed EoA: 0–min. 2 wk
Homogeneous iso- to hypodense SDC
1) Hyperacute SDHUnclotted bloodAssumed EoA: 0–24 hr
2) Acute SDH + anemiaClotted blood with decreased number of erythrocytesAssumed EoA: 1–3 days
3) SDHy/SDHHyCSF or CSF + acute bloodAssumed EoA: 1 day–min. 1 wk
4) Late subacute SDHLysis of erythrocytesAssumed EoA: 1–3 wk
5) cSDHSerosanguinous fluidAssumed EoA: min. 2 wk

  • Note:—EoA indicates estimate of age; min, minimum.

  • ↵a According to Hymel et al,20 Hedlund,22 Vezina,28 and Tung et al.30