1：Experimental Design and Method Selection:

A prospective study design was used to compare digital and analog PET/CT systems. Patients underwent a single-day, dual imaging protocol with both systems after a single radiotracer injection. Image quality was assessed using a 4-point scale, and lesion detection was evaluated by counting lesions with increased radiotracer uptake. Statistical analysis included chi-squared tests, Student t-tests, and Cohen's kappa coefficient for agreement.

2：Sample Selection and Data Sources:

100 consecutive oncological patients (62 men, 38 women; mean age 65 ± 12 years) referred for PET/CT assessment or monitoring were included. Patients had various cancers, including lung, breast, colorectal, and others. Data were acquired from PET/CT scans.

3：List of Experimental Equipment and Materials:

Philips digital VEREOS PET/CT system, Philips analog GEMINI TF PET/CT system, radiotracers (18F-FDG or 18F-FluoroCholine), Philips IntelliSpace Portal workstation v8.0 for image review.

4：0 for image review. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: Patients fasted for at least 6 hours before radiotracer injection (approximately

5：7 MBq per kg). PET/CT scans were performed 60 minutes post-injection, with the second scan after a mean delay of 50 ± 14 minutes. CT acquisition parameters:

120kVp, tube current modulation, pitch

6：828, 3 mm slice thickness. PET acquisition:

2 minutes/bed position, list-mode TOF acquisition. Reconstruction used 3D-OSEM algorithm with specific iterations and subsets for each system.

7：Data Analysis Methods:

Image quality was rated by three nuclear medicine physicians. Lesion counts were compared using statistical tests in IBM SPSS Statistics V25 software. Significance was set at p < 0.05.