Correlations Between MR Apparent Diffusion Coefficients and PET Standard Uptake Values in Simultaneous MR-PET Imaging

Andrii Pozaruk1,2,3, Vitaliy Atamaniuk2, Kamlesh Pawar3,4

  • 1Department of Photomedicine and Physical Chemistry, Institute of Medical Sciences, The Medical College of The University of Rzeszów, 35-310 Rzeszów, Poland.

Insights

Advanced deep learning (DL) for 68Gallium-PSMA-11 (Ga-PSMA-11) PET SUV improves correlation with MR ADC maps in prostate cancer patients compared to conventional PET-MR. This finding aids in better disease characterization.

Area of Science:

  • Nuclear medicine imaging
  • Radiopharmaceuticals
  • Prostate cancer diagnostics

Background:

  • 68Ga-PSMA-11 PET/CT is crucial for prostate cancer staging.
  • MR diffusion-weighted imaging (DWI) provides insights into tissue microstructure via apparent diffusion coefficient (ADC) maps.
  • Integrating PET SUV and ADC values may enhance diagnostic accuracy.

Purpose of the Study:

  • To evaluate if deep learning (DL)-derived 68Ga-PSMA-11 PET Standardized Uptake Values (SUV) correlate better with MR ADC maps than conventional PET-MR SUV.
  • To determine the optimal SUV threshold for maximum correlation with ADC values.

Main Methods:

  • A cohort of 32 prostate cancer patients underwent CT and PET-MR imaging.
  • K-fold cross-validation (4 folds) was used for training (24 patients) and validation (8 patients) of DL models.
  • ADC maps were aligned with T2 images for 27 patients to analyze correlations between ADC and SUV values.

Main Results:

  • An inverse correlation was observed between ADC and SUV values in prostate cancer lesions (ρ = -0.20 to -0.51).
  • Statistically significant differences in mean SUV values were found between conventional PET-MR and DL-based PET (PETDL).
  • DL-based SUV values demonstrated a stronger correlation with ADC values compared to conventional PET-MR SUV.

Conclusions:

  • DL-based 68Ga-PSMA-11 PET SUV shows improved correlation with MR ADC maps in prostate cancer.
  • This advanced DL approach may offer more precise characterization of prostate cancer compared to conventional methods.