Dose length product (DLP) is a measure of CT tube radiation output. It is related to CTDIvol, but CTDIvol represents the dose through a slice of an appropriate phantom. DLP accounts for the length of radiation output along the z axis (the long axis of the patient).
DLP = (CTDIvol ) * (length of scan, cm)
It is important to remember that DLP is not the patient's effective dose. The effective dose depends on other factors including patient size and the region of the body being scanned.
Some factors have been estimated to convert DLPs into effective doses, depending on the body region. If interested, consult reference 3.
- 1. Jerrold T. Bushberg, John M. Boone. The Essential Physics of Medical Imaging. ISBN: 9780781780575
- 2. Durand DJ, Mahesh M. Understanding CT dose display. (2012) Journal of the American College of Radiology : JACR. 9 (9): 669-71. doi:10.1016/j.jacr.2012.06.003 - Pubmed
- 3. Walter Huda, Kent M. Ogden, Mohammad R. Khorasani. Converting Dose-Length Product to Effective Dose at CT. (2008) Radiology. 248 (3): 995-1003. doi:10.1148/radiol.2483071964 - Pubmed
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