A reliable and robust method for the upper thigh muscle quantification on computed tomography: toward a quantitative biomarker for sarcopenia

Youngbin Shin,Kyung Won Kim,Jisuk Park,Yu Sub Sung,Jimi Huh,Jiwoo Lee,Hye Sun Ko,Jei Hee Lee,Jai Keun Kim,Yousun Ko

doi:10.1186/s12891-022-05032-2

Youngbin Shin, Kyung Won Kim + Show 8 more

Open Access

https://doi.org/10.1186/s12891-022-05032-2

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Abstract

BackgroundWe aimed to evaluate the feasibility of the upper thigh level as a landmark to measure muscle area for sarcopenia assessment on computed tomography (CT).MethodsIn the 116 healthy subjects who performed CT scans covering from mid-abdomen to feet, the skeletal muscle area in the upper thigh level at the inferior tip of ischial tuberosity (SMAUT), the mid-thigh level (SMAMT), and L3 inferior endplate level (SMAL3) were measured by two independent readers. Pearson correlation coefficients between SMAUT, SMAMT, and SMAL3 were calculated. Inter-reader agreement between the two readers were evaluated using intraclass correlation coefficient (ICC) and Bland-Altman plots with 95% limit of agreement (LOA).ResultsIn readers 1 and 2, very high positive correlations were observed between SMAUT and SMAMT (r = 0.91 and 0.92, respectively) and between SMAUT and SMAL3 (r = 0.90 and 0.91, respectively), while high positive correlation were observed between SMAMT and SMAL3 (r = 0.87 and 0.87, respectively). Based on ICC values, the inter-reader agreement was the best in the SMAUT (0.999), followed by the SMAL3 (0.990) and SMAMT (0.956). The 95% LOAs in the Bland-Altman plots indicated that the inter-reader agreement of the SMAUT (− 0.462 to 1.513) was the best, followed by the SMAL3 (− 9.949 to 7.636) and SMAMT (− 12.105 to 14.605).ConclusionMuscle area measurement at the upper thigh level correlates well with those with the mid-thigh and L3 inferior endpoint level and shows the highest inter-reader agreement. Thus, the upper thigh level might be an excellent landmark enabling SMAUT as a reliable and robust biomarker for muscle area measurement for sarcopenia assessment.

Highlights

We aimed to evaluate the feasibility of the upper thigh level as a landmark to measure muscle area for sarcopenia assessment on computed tomography (CT)
Sarcopenia is a muscle disease rooted in adverse muscle changes that accrue across a lifetime [1], and it has recently been assigned the International Classification of Disease (ICD-10CM) code [2]
In readers 1 and 2, very high positive correlations were observed between SMAUT and S MAMT (r = 0.91 and 0.92, respectively) and between SMAUT and SMAL3 (r = 0.90 and 0.91, respectively), while high positive correlation were observed between SMAMT and SMAL3 (r = 0.87 and 0.87, respectively) (Table 2)

Summary

Introduction

We aimed to evaluate the feasibility of the upper thigh level as a landmark to measure muscle area for sarcopenia assessment on computed tomography (CT). A variety of landmarks, such as the third lumbar vertebral (L3) and mid-thigh, have been used for quantification of muscle area on CT [1, 5,6,7,8]. It has been reported that the skeletal muscle area measured at the level of the L3 correlates well with whole-body muscle mass [9]. Mid-thigh imaging has been used in many research studies because it is a good predictor of appendicular muscle as well as whole-body skeletal muscle [11, 12]. The mid-thigh level might not be included in the routine abdominopelvic CT, requiring a dedicated CT scan for the thigh

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