Assessment of gluteus maximus muscle area with different image analysis programs.
OBJECTIVE
To determine the effectiveness of a percutaneous gluteal stimulation system (GSTIM) by comparing assessments of axial computed tomography (CT) scans for the pelvic area.


METHODS
Comparing the measurements of the cross-sectional area (CSA) of the gluteus maximus muscle between raters and 2 image analysis programs.


METHODS
Retrospective axial CT scans of the pelvic area.


METHODS
Men (N=9) with complete (below T6) spinal cord injury (SCI) and at least 2 years postinjury participated in the study (range, 29-75y; mean age, 51.8y).


METHODS
Comparing gluteus maximus CSA before and after a period of GSTIM.


METHODS
Measurements made by 2 expert and 2 nonexpert raters were used to compare the repeatability and reliability of measuring muscle CSA. The longitudinal study presented is from repeated CT scans obtained over a 2-year period for 1 representative participant who received a GSTIM system.


RESULTS
For repeatability, nonexpert raters measured a mean CSA of 35.2 cm2 (range, 20-45 cm2), while experts measured 21 cm2 (range, 10-35 cm2). A composite of all raters using the same program had SDs of 2.5 to 2.6 cm2 for a program available through the National Institutes of Health and 2.5 to 4.4 cm2 for a commercially available program. For reliability, differences between the 2 programs had mean differences in SD between 2.2 and 3.7 cm2.


CONCLUSIONS
The same rater and program (preferably the more reliable ImageJ) is recommended for the course of a longitudinal study. Otherwise, significant error would be introduced. Furthermore, significant increases in the CSA of gluteal muscle compared with preintervention (baseline) measurements were observed for the participant receiving GSTIM.
Wu
Gary A
GA
Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
Bogie
Kath
K
D000328:Adult; D000368:Aged; D002081:Buttocks; D004599:Electric Stimulation Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D009133:Muscular Atrophy / Q000000981:diagnostic imaging / Q000209:etiology / Q000534:rehabilitation*; D015588:Observer Variation; D010388:Pelvis; D015203:Reproducibility of Results; D013119:Spinal Cord Injuries / Q000150:complications; D014057:Tomography, X-Ray Computed