Tutorial for Using SliceOmatic to Calculate Thigh Area and Composition from Computed Tomography Images from Older Adults

Authors

Richard A. Dennis, Central Arkansas Veterans Healthcare System
Douglas E. Long, University of KentuckyFollow
Reid D. Landes, University of Arkansas for Medical Sciences
Kalpana P. Padala, Central Arkansas Veterans Healthcare System
Prasad R. Padala, Central Arkansas Veterans Healthcare System
Kimberly K. Garner, Central Arkansas Veterans Healthcare System
James N. Wise, University of Arkansas for Medical Sciences
Charlotte A. Peterson, University of KentuckyFollow
Dennis H. Sullivan, Central Arkansas Veterans Healthcare System

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.

Document Type

Article

Publication Date

10-2-2018

Notes/Citation Information

Published in PLOS ONE, v. 13, no. 10, e0204529, p. 1-17.

This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Digital Object Identifier (DOI)

https://doi.org/10.1371/journal.pone.0204529

Funding Information

This work was supported by Merit Review Award RX0012030 to RAD from the United States Department of Veterans Affairs, Rehabilitation Research and Development Service (https://www.research.va.gov/services/rrd.cfm) but does not represent the views of the VA or US Government.

Related Content

All relevant data are within the paper and its Supporting Information files.

S1 File. This is the Scan 1.dcm file. https://doi.org/10.1371/journal.pone.0204529.s001 (DCM)

S2 File. This is the Scan 2.dcm file. https://doi.org/10.1371/journal.pone.0204529.s002 (DCM)

S3 File. This is the Scan 3.dcm file. https://doi.org/10.1371/journal.pone.0204529.s003 (DCM)

S4 File. This is the Scan 4.dcm file. https://doi.org/10.1371/journal.pone.0204529.s004 (DCM)

S5 File. This is the Scan 5.dcm file. https://doi.org/10.1371/journal.pone.0204529.s005 (DCM)

S6 File. This is the Thigh Segmentation Tutorial.scp file. https://doi.org/10.1371/journal.pone.0204529.s006 (SCP)

S7 File. This is the Thigh Threshold 1.scp file. https://doi.org/10.1371/journal.pone.0204529.s007 (SCP)

S8 File. This is the Thigh Threshold 2.scp file. https://doi.org/10.1371/journal.pone.0204529.s008 (SCP)

S9 File. This is the Scan Analysis Dataset.xlsx file. https://doi.org/10.1371/journal.pone.0204529.s009 (XLSX)

S10 File. This is the Results.csv file. https://doi.org/10.1371/journal.pone.0204529.s010 (CSV)

Repository Citation

Dennis, Richard A.; Long, Douglas E.; Landes, Reid D.; Padala, Kalpana P.; Padala, Prasad R.; Garner, Kimberly K.; Wise, James N.; Peterson, Charlotte A.; and Sullivan, Dennis H., "Tutorial for Using SliceOmatic to Calculate Thigh Area and Composition from Computed Tomography Images from Older Adults" (2018). Center for Muscle Biology Faculty Publications. 6.
https://uknowledge.uky.edu/musclebiology_facpub/6