A standard needle used in intramuscular injections to the thigh site would be effective in reaching the muscle in the rectus femoris and vastus lateralis sites in all men and in 77.8% of women, although it is not usually adequate for gluteal injection.

The most commonly used areas in the lower extremity in subcutaneous injection applications are anterior and lateral surface of the thigh. The calf region, which is an alternative to these areas, is located in the lateral region of the gastrocnemius muscle. The aim of the study is to retrospectively evaluate of suitability of thigh and calf site subcutaneous adipose tissue thickness for subcutaneous injection through computed tomography sections. The sample of this descriptive study consisted of 140 adult patients over the age of 18 who underwent Contrast-Enhanced Lower Extremite Computed Tomography Angiography between March 2020 and March 2021. Subcutaneous tissue thicknesses of the anterior thigh, lateral thigh, and calf injection site of the subjects were measured by a specialist radiologist using computed tomography sections. As a result of the study, a comparison of subcutaneous tissue thickness in the thigh and calf was achieved according to gender and body mass index. The mean subcutaneous tissue thickness of the patients was 13.64 ± 6.85 mm on the anterior thigh, 8.82 ± 7.21 mm on the lateral side of the thigh, and 6.15 ± 3.12 mm in the calf area. It was found that there was a significant difference between subcutaneous tissue thicknesses according to their gender and body mass index. Subcutaneous tissue thickness on the anterior thigh was thicker than the lateral thigh and the calf injection site. Subcutaneous tissue thickness in females was greater than in males. Subcutaneous tissue thickness in the calf region was thicker than 4 mm in 77.1%, 8 mm in 19.3% and 12 mm in 12.3%.