Uws mi r004

Two experienced nuclear physicians evaluated the image quality of ⁶⁸Ga-DOTA-TATE PET images reconstructed using OSEM and TVREM independently on a commercial workstation (uWS-MI R004, United Imaging Healthcare). The nuclear physicians evaluated the images using a 5-point scale without knowing the reconstruction parameters (Table 1). The image of 5-point was with excellent image quality, almost free of noise, ideal contrast and sharp border. The image of 4-point was with good image quality, and its noise did not affect the identification and diagnosis of the lesion at all. The image of 3-point was with moderate image quality, obvious noise, and sufficient lesion delineation to make a diagnosis. The image of 2-point was barely acceptable, and the noise was large, which affected the diagnosis. The image of 1-point had the worst image quality and could not be used for diagnosis at all.

ThE PET images were independently evaluated on a dedicated workstation (uWS-MI R004, United Imaging Healthcare) by two nuclear radiologists with 10 years of experience each. All images were anonymized and labelled with randomly assigned numbers to reduce bias, and the radiologists rated the images without knowing the reconstruction settings. PET datasets were rated using a five-point Likert scale (1 = poor image quality with excessive noise or unnatural texture, and insufficient lesion depiction; 2 = unacceptable image quality with suboptimal noise, or poor lesion contrast and delineation leading to low diagnostic confidence; 3 = acceptable image quality with appropriate noise, sufficient lesion delineation, and sufficiently natural image texture to make a diagnosis; 4 = good image quality with optimal noise and satisfactory lesion delineation resulting in full diagnostic confidence. 5 = excellent image quality with almost zero noise, perfect contrast between the lesion and the background, and a sharp border delineating the lesion from the rest of the organ).