General Objective of the Project

The goal of the project is to study the influence of liver activity during its cranio-caudal respiratory motion on myocardial perfusion imaging (MPI) using, in the supine and prone positions, an anthropomorphic thorax phantom assembly with precisely controlled motions of thoracic organs, consisting of (a) an existing beating and moving during respiration human-sized left ventricle phantom with variable sizes of cardiac defects, (b) an existing human-sized and human-shaped inflatable lungs phantom, (c) a proposed human-shaped and human-shaped moving during respiration liver phantom.

Specific Scientific and Technological Objectives of the Project

(a) Develop a human-sized and human-shaped liver phantom which will be precisely controlled to move in the cranio-caudal direction during respiration, and implement it within the existing anthropomorphic thorax phantom assembly together with the (i) inflatable lungs, and (ii) beating and moving cardiac phantom with variable sizes of cardiac defects,

(b) Acquire and process MP images at the three consortium Nuclear Medicine Departments (the only two public ones, and the corresponding one from the main Oncology Center in Cyprus) using the corresponding SPECT modalities and the elaborated phantom assembly in supine and prone positions with various (i) sizes of cardiac defects, (ii) hepatic-to-heart activity ratios, (iii) hepatic-to-heart proximities, and (iv) cardiac-lungs-liver oscillation amplitudes during respiration in the cranio-caudal direction (normal and deep breathing),

(c) Characterize quantitatively artifacts due to various hepatic-to-heart activity ratios for various (i) hepatic-to-heart proximities, (ii) cardiac-lungs-liver oscillation amplitudes during the respiratory motion, (iii) attenuation, (iv) misalignment between transmission (CT) and emission scans (SPECT), and for (v) the phantom assembly at supine and prone positions,

(d) Investigate the impact of artifacts due to various hepatic-to-heart activity ratios on cardiac defect detection from the evaluation of physicians’ reports,

(e) Correct AC-SPECT images for the respiratory motion of the heart under the influence of the liver activity using the image-based method, and compare them quantitatively with the non-corrected images,

(f) Investigate the impact of the proposed cardiac motion correction on cardiac defect detection from the evaluation of physicians’ reports,

(g) Compare supine and prone imaging under the influence of liver activity concerning (i) artifacts, (ii) motion correction, and (iii) impact on defect detection,

(h) Compare the performance of different methods of acquiring attenuation maps on defect defection,

(i) Determine the imaging procedure that results in the best diagnostic value, considering the influence the liver activity on MPI and also patient dose as a constraint.