Hounsfield unit average calculation (HUAC)

Last revised by Rohit Sharma on 26 Dec 2019

Citation, DOI, disclosures and article data

Citation:

Smith D, Sharma R, Bell D, Hounsfield unit average calculation (HUAC). Reference article, Radiopaedia.org (Accessed on 25 Apr 2024) https://doi.org/10.53347/rID-61365

DOI:

https://doi.org/10.53347/rID-61365

Permalink:

https://radiopaedia.org/articles/61365

rID:

61365

Article created:

29 Jun 2018, Derek Smith ◉

Disclosures:

At the time the article was created Derek Smith had no recorded disclosures.

View Derek Smith's current disclosures

Last revised:

26 Dec 2019, Rohit Sharma ◉

Disclosures:

At the time the article was last revised Rohit Sharma had no recorded disclosures.

View Rohit Sharma's current disclosures

Revisions:

4 times, by 3 contributors - see full revision history and disclosures

Systems:

Musculoskeletal

Tags:

cases

Synonyms:

HUAC

Hounsfield unit average calculation (HUAC) is an imaging marker of sarcopenia, a key component of frailty ¹. Psoas muscle assessment at L4 level is typically performed ¹.

Sarcopenia has been associated with poor outcomes in trauma, oncology and surgical cases.

Hounsfield unit average calculation has been proposed as a novel "point-of-care" objective assessment of frailty. It can also be calculated using imaging alone as it is independent of patient height. Most patients undergoing surgery or treatment will undergo cross-sectional imaging, and the typical level for analysis is at L4. Segmentation software or a simple freestyle region of interest (ROI) provide area and average HU figures.

HUAC
- (right area x density) + (left area x density) / total area

Levels to determine sarcopenia varies between publications (26 - 38 ^2,3) but is taken as the lowest quartile of values for your population, adjusted for gender.