Table 1.

Overview on methodological details for the measurements of SDH width, length and depth in studies with acute or chronic subdural hematomas

	Reference; year
	Gebel et al. [11]; 1998	Sucu et al. [12]; 2005	Won et al. [13]; 2018
Patients	298 intraparenchymal hematomas and 44 acute subdural hematomas in 244 patients	28 patients with unilateral chronic subdural hematoma	82 patients with 100 chronic subdural hematomas
Length (A)	A representative slice at the center of the hematoma Maximum length = linear distance between each corner of the subdural crescent	A1: maximum length on any slice A2: length on slice that is at the center A3: length on slice that has maximum corrected width	Maximum length (anterior to posterior) to each corner of the SDH
Width (B)	A representative slice near the center of the hematoma Maximum thickness = from the inner table of the skull perpendicular	B1: maximum width on any slice B2: width on slice at the center B3: corrected width on slice at the center B4: corrected width on slice which has maximum corrected width	Maximum width 90 ° to maximum length in the same slice as length (A)
Depth (C)	Number of slices on which hematoma was visible × slice thickness	Number of slices on which hematoma was visible × slice thickness	Number of slices with visible hematoma × thickness of CT-scan or a coronal plane was used
Volume formula	A × B × C / 2	A × B × C / 2 with 5 formulas: 1. A1 × B1 × C / 2 2. A2 × B2 × C / 2 3. A2 × B3 × C / 2 4. A3 × B4 × C / 2 5. A1 × B4 × C / 2	A × B × C / 2