Nucl Med Commun. 2026 Jul 7. doi: 10.1097/MNM.0000000000002203. Online ahead of print.
ABSTRACT
AIM/INTRODUCTION: Adenosine pharmacological stress is commonly used for the detection of ischemia by myocardial perfusion imaging (MPI) using radiotracers and gated single-photon emission computed tomography/computed tomography (SPECT/CT) imaging. Recently, a phenomenon, splenic switch-off (SSO), has been observed where reduced perfusion to the spleen occurs after adenosine, suggesting an adequate effect of adenosine on the heart. The aim of the study is to evaluate the SSO effect in adenosine stress 99mTc tetrofosmin MPI studies using semiquantitative analysis of SPECT/CT data.
MATERIALS AND METHODS: Seventeen adenosine MPI studies were selected. Each study included stress and rest, which were reoriented in short, horizontal, and vertical long axes. Also, data were reconstructed in the body transaxial, coronal, and sagittal planes. In the resulting images, the spleen was identified on the CT component, and regions of interest were drawn on the spleen, thoracic vertebra, and myocardium. The ratios spleen/vertebra (S/VAd and S/VRst) and myocardium/vertebra (M and M/t) were calculated. Statistical analysis was done using a paired t test.
RESULTS: Mean age was 60.35 years, with 9 males (53%). Mean S/VAd was 0.98 ± 0.38 and S/VRst 1.87 ± 0.87 (t = -3.707, P < 0.01). The mean M/VAd was 2.86 ± 1.65 and M/VRst 3.75 ± 2.41 (t = -1.323, P = 0.204).
CONCLUSION: Using the method outlined, especially the S/V ratio, evaluation of the SSO can be achieved from the acquired data, which shows promise as a marker for adequate effectiveness of adenosine stress in doubtful cases.
PMID:42411251 | DOI:10.1097/MNM.0000000000002203
