Likert score and Prostate Imaging Reporting And Data System (PI - RADS score) to assess the likelihood of prostate cancer based on multiparametric MRI

Two scoring systems are commonly used to evaluate the likelihood of prostate cancer on multiparametric MRI:

• Prostate Imaging Reporting And Data System version 2 (PI-RADS_v2) which uses explicit criteria based on a zonal multiparametric MRI (mpMRI) dominant sequence (e.g. diffusion-weighted imaging in the peripheral zone (PZ) and T2 weighted imaging in the transition zone) to rate the suspicion of prostate cancer on a 5-point scale and
  
  
• a subjective 5-point Likert assessment, based on each mpMRI sequence equally (unlike the use of dominant sequence in PIRADS_v2) and adapted to the radiologist's experience for overall impression

Both 5-point scales define the likelihood for the presence of prostate cancer, as follows

• (1) highly unlikely,
• (2) unlikely,
• (3) equivocal,
• (4) likely,
• (5) highly likely

Reference:

• Renard-Penna R et al. Prostate imaging reporting and data system and Likert scoring system: multiparametric MR imaging validation study to screen patients for initial biopsy. Radiology 2015; 275: 458-68.
• Rosenkrantz AB et al. Comparison of interreader reproducibility of the prostate imaging reporting and data system and likert scales for evaluation of multiparametric prostate MRI. AJR Am J Roentgenol 2013; 201: W612-W618.