Apical left ventricular radiotracer uptake on attenuation correction with SPECT/TDM myocardial perfusion scintigraphy in non-ischemic patients

Introduction. - Attenuation correction (AC) has been shown to improve the accuracy of myocardial perfusion single photon emission computed scintigraphy (SPECT). It often reveals a decrease in apical uptake in the AC of the left ventricular (LV) in non-ischemic patients. We aimed to identify the parameters that could affect the apical radiotracer uptake in non-ischemic patients. Materials and methods. - Prospectively, we included 340 consecutive non-ischemic patients. They underwent sequential CT and myocardial SPECT imaging. We studied the apical uptake with the AC (combined to scatter correction, resolution recovery and noise regularization) and its correlation with various parameters related to patient and the technique. Results. - The apical uptake with AC was lower than with filtered back projection (FBP). On univariate analysis, several parameters correlated to apical uptake with AC, of which only 4 remained significant on step-by-step regression analysis: uptake with FBP, angle of the LV in the frontal plane, type of stress, arm's position at acquisition. These four parameters explain 51% of the variation of apical uptake with CA. Conclusions. - Apical uptake in myocardial perfusion scintigraphy is lower with AC compared with RPF in non-ischemic patients. The apical uptake with AC is correlated to that of FBP, angle of the LV in the frontal plane, type of stress and arm's position at acquisition. (C) 2018 Elsevier Masson SAS. All rights reserved.