Intra-session and inter-rater reliability of spatial frequency analysis methods in skeletal muscle

Abstract

Spatial frequency analysis (SFA) is a quantitative ultrasound (US) method originally developed to assess intratendinous tissue structure. This method may also be advantageous in assessing other musculoskeletal tissues. Although SFA has been shown to be a reliable assessment strategy in tendon tissue, its reliability in muscle has not been investigated. The purpose of this study was to examine the reliability of spatial frequency parameter measurement for a large muscle group within a healthy population. Ten participants with no history of lower extremity surgery or hamstring strain injury volunteered. Longitudinal B-mode images were collected in three different locations across the hamstring muscles. Following a short rest, the entire imaging procedure was repeated. B-mode images were processed by manually drawing a region of interest (ROI) about the entire muscle thickness. Four spatial frequency parameters of interest were extracted from the image ROIs. Intra-and inter-rater reliabilities of extracted SFA parameters were performed. Test-retest reliability of the image acquisition procedure was assessed between repeat trials. Intraclass correlation coefficients showed high intra-and inter-rater reliability (ICC(3,1) > 0.9 for all parameters) and good to moderate test-retest reliability (ICC(3,1) > 0.50) between trials. No differences in parameter values were observed between trials across all muscles and locations (p > 0.05). The high reliability metrics suggest that SFA will be useful for future studies assessing muscle tissue structure, and may have value in assessing muscular adaptations following injury and during recovery.

Reproducibility of freehand vs. foam cast as well as the intrarater reliability of foam cast ultrasound scans assessing the muscle architecture and tissue organization of the gastrocnemius medialis and vastus lateralis muscles

“…After image acquisitions were completed for one condition, the participant sat on the examination table for 60 s ( 13 ), before laying back down to get measured again for the next condition ( Figure 1 ). The measurements were performed in randomized order ( Figure 1 ).…”

Spatial-frequency Analysis of the Anatomical Differences in Hamstring Muscles

“…SFA parameters were previously shown to have excellent reliability when performed by a single rater. 31…”

“…SFA was performed similar to previous descriptions 28,29,31 with the exception of an increased ROI size. All possible 96 × 96 pixel (~6.6 mm) sub-images (kernels) within the ROI were analyzed in the spatial frequency domain.…”

“…A recent investigation adapted and extended SFA for use in skeletal muscle, showing it to have good intra- and inter-rater reliability. 31…”

Skeletal Muscle Assessment Using Quantitative Ultrasound: A Narrative Review

“…Crawford et al investigated the reliability of spatial frequency parameter measurements for a muscle group in healthy subjects. The inter-class correlation coefficients showed high intra- and inter-rater reliability and good to moderate test-retest reliability [ 42 ]. An additional study showed SFA could detect architectural differences in multiple hamstring muscles with significant differences between different regions of healthy muscle structure [ 22 ].…”