DoseSave
← All tools

Dose Calculators (DLP → E & SSDE)

The two most frequent dose estimations in medical physics: effective dose from DLP (via k-factors) and Size-Specific Dose Estimates (SSDE, AAPM Report 204).

100% client-side · No data is sent to a server

1. DLP → Effective Dose (E)

Estimate effective dose from the CT dose–length product (DLP) with a k-factor.

E (mSv) = DLP (mGy·cm) × k (mSv·mGy−1·cm−1)
mGy·cm
Effective dose estimate (E) 7,00 mSv
Inputs, method and reference are copied as a consultation note.
Sources, scope and limits

k-factors: Adult reference values defined in the European Commission CT quality criteria guidelines (EUR 16262) and AAPM Report 96.

  • Not a patient organ dose: Effective dose (E) is a quantity defined by the ICRP to compare population risk and stochastic cancer probability. It does not give an individual patient's organ dose.
  • Paediatric patients are out of scope: Because children have a smaller body diameter, k-factors are 1.3× to 2.8× higher depending on age.

2. SSDE — Size-Specific Dose Estimate

Correction of body CT CTDIvol for patient size (AAPM Report 204, 32 cm phantom).

SSDE = CTDIvol,32 × f    f = 3,704369 · e−0,03671937 · d    d = √(AP × LAT)
mGy
cm
cm
Hesaplanan SSDE — mGy
Inputs, method and reference are copied as a consultation note.
Sources, scope and limits

Method: AAPM Report 204 (Size-Specific Dose Estimates in Pediatric and Adult Body CT Examinations). The conversion factor for CTDIvol referenced to the 32 cm PMMA phantom is an exponential function of the effective diameter (d, cm): f = 3,704369 · e−0,03671937·d.

  • Body CT and 32 cm phantom only: CTDIvol reported for the 16 cm phantom cannot be used directly with this formula.
  • Kafa SSDE'si: Head CT uses a separate method (AAPM Report 293).
  • SSDE is not an organ dose: It is a scanner output index corrected for patient size.