Validity of ultrasound imaging for intrinsic foot muscle cross-sectional area measurements demonstrated by strong agreement with MRI

Table 2 Mean ICC and SEm values for US and MRI

Muscle	US - ICC_3,1 (95% CI)	MRI - ICC_3,1 (95% CI)	US - SEm (95% CI)	MRI - SEm (95% CI)
Right foot
FHB	0.994 (0.989, 0.997)	0.998 (0.995, 0.999)	0.028 (1.35, 1.46)	0.020 (1.37, 1.43)
ABDH	0.997 (0.994, 0.998)	0.998 (0.995, 0.999)	0.031 (2.41, 2.53)	0.023 (2.49, 2.58)
FDB	0.993 (0.985, 0.996)	0.998 (0.997, 0.999)	0.044 (2.2, 2.37)	0.023 (2.31, 2.4)
QP	0.997 (0.995, 0.999)	0.999 (0.997, 0.999)	0.032 (1.86, 1.98)	0.019 (1.86, 1.94)
ADM	0.994 (0.989, 0.997)	0.997 (0.994, 0.998)	0.029 (1.22, 1.33)	0.020 (1.23, 1.31
Left foot
FHB	0.991 (0.982, 0.995)	0.997 (0.995, 0.999)	0.032 (1.29, 1.42)	0.020 (1.34, 1.41)
ABDH	0.996 (0.991, 0.998)	0.999 (0.998, 0.999)	0.038 (2.38, 2.53)	0.012 (2.47, 2.54)
FDB	0.996 (0.993, 0.998)	0.999 (0.997, 0.999)	0.035 (2.2, 2.33)	0.017 (2.28, 2.35)
QP	0.996 (0.993, 0.998)	0.999 (0.998, 1.00)	0.037 (1.84, 1.99)	0.020 (1.87, 1.95)
ADM	0.994 (0.989, 0.997)	0.997 (0.993, 0.998)	0.026 (1.24, 1.34)	0.018 (1.25, 1.32)

All values reported in cm². ICC intraclass correlation coefficients, SEm standard error of the measurement, FHB flexor hallucis brevis, ABDH abductor hallucis, FDB flexor digitorum brevis, QP quadratus plantae, ADM abductor digiti minimi

ISSN: 1471-2474