Title | Tutorial for using SliceOmatic to calculate thigh area and composition from computed tomography images from older adults. |
Publication Type | Journal Article |
Year of Publication | 2018 |
Authors | Dennis RA, Long D, Landes RD, Padala KP, Padala PR, Garner KK, Wise JN, Peterson CA, Sullivan DH |
Journal | PLoS One |
Volume | 13 |
Issue | 10 |
Pagination | e0204529 |
Date Published | 2018 |
ISSN | 1932-6203 |
Keywords | Adipose Tissue, Aged, Bone and Bones, Humans, Image Interpretation, Computer-Assisted, Male, Middle Aged, Muscle, Skeletal, Organ Size, Resistance Training, Thigh, Tomography, X-Ray Computed, Treatment Outcome, User-Computer Interface, Veterans |
Abstract | OBJECTIVE: Area of muscle, fat, and bone is often measured in thigh CT scans when tissue composition is a key outcome. SliceOmatic software is commonly referenced for such analysis but published methods may be insufficient for new users. Thus, a quick start guide to calculating thigh composition using SliceOmatic has been developed. METHODS: CT images of the thigh were collected from older (69 ± 4 yrs, N = 24) adults before and after 12-weeks of resistance training. SliceOmatic was used to segment images into seven density regions encompassing fat, muscle, and bone from -190 to +2000 Hounsfield Units [HU]. The relative contributions to thigh area and the effects of tissue density overlap for skin and marrow with muscle and fat were determined. RESULTS: The largest contributors to the thigh were normal fat (-190 to -30 HU, 29.1 ± 7.4%) and muscle (35 to 100 HU, 48.9 ± 8.2%) while the smallest were high density (101 to 150 HU, 0.79 ± 0.50%) and very high density muscle (151 to 200 HU, 0.07 ± 0.02%). Training significantly (P<0.05) increased area for muscle in the very low (-29 to -1 HU, 5.5 ± 7.9%), low (0 to 34 HU, 9.6 ± 16.8%), normal (35 to 100 HU, 4.2 ± 7.9%), and high (100 to 150 HU, 70.9 ± 80.6%) density ranges for muscle. Normal fat, very high density muscle and bone did not change (P>0.05). Contributions to area were altered by ~1% or less and the results of training were not affected by accounting for skin and marrow. CONCLUSIONS: When using SliceOmatic to calculate thigh composition, accounting for skin and marrow may not be necessary. We recommend defining muscle as -29 to +200 HU but that smaller ranges (e.g. low density muscle, 0 to 34 HU) can easily be examined for relationships with the health condition and intervention of interest. TRIAL REGISTRATION: Clinicaltrials.gov NCT02261961. |
DOI | 10.1371/journal.pone.0204529 |
Alternate Journal | PLoS ONE |
PubMed ID | 30278056 |
PubMed Central ID | PMC6168133 |
Grant List | I01 RX001203 / RX / RRD VA / United States |