Prognostic value of lower limb perfusion single-photon emission computed tomography-computed tomography in patients with lower limb atherosclerotic peripheral artery disease

Purpose The purpose of this study was to estimate the severity of the participants’ lower limb ischemia by calculating the lower limb muscle-to-background ratio (LMBR) using lower limb perfusion single-photon emission computed tomography-computed tomography (SPECT/CT) and to evaluate the prognostic value of LMBR in peripheral artery disease (PAD) patients. Materials and methods This retrospective study consists of 38 patients with PAD (70 ± 12 years) and observed over 1 year who were included in the analysis. All participants underwent lower limb perfusion SPECT/CT. LMBR was calculated by dividing counts/volume in lower limb muscle by mean counts/volume of background. All patients were divided into two groups based on their LMBR value and observed for the occurrence of a major adverse event (MAE). Results The high and low LMBR groups consisted of 26 and 12 patients, respectively. The median LMBR in the high group was 9.59 (6.11–11.87) while that in the low group was 4.35 (3.85–4.99). A significantly higher number of patients in the low LMBR group experienced MAE than in the high LMBR group (7 of 12 vs. 1 of 26, p < 0.001). Conclusion This study demonstrated that the LMBR derived from lower limb perfusion SPECT/CT may have a high prognostic value in patients with PAD.