3458731 SMFI skeletal muscle fat index 7 3458734 SMFI Single-molecule fluorescence imaging 5 3458730 SMFI severe male factor infertility 1 3458732 SMFI SMF index 1 3458733 SMFI St. Mark's Fecal Incontinence score 1 3458729 SMFI supraspinatus muscle fatty infiltration 1 3458728 SMFI suspected maternofetal infection 1