PI-RADS V.2

 

  1. PIRADS 1 – Very low (clinically significant cancer is highly unlikely to be present)
  2. PIRADS 2 – Low (clinically significant cancer is unlikely to be present)
  3. PIRADS 3 – Intermediate (the presence of clinically significant cancer is equivocal)
  4. PIRADS 4 – High (clinically significant cancer is likely to be present)
  5. PIRADS 5 – Very high (clinically significant cancer is highly likely to be present)

 

     
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    DWI PZ
     
    T2 TZ.jpg
     
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    The segmentation model used in PI-RADSTM v2 employs thirty-nine sectors/regions: thirty-six for the prostate, two for the seminal vesicles and one for the external urethral sphincter. 

    The prostate is divided into right/left on axial sections by a vertical line drawn through the center (indicated by the prostatic urethra), and into anterior/posterior by a horizontal line through the middle of the gland. 

    The right and left peripheral zones (PZ) at prostate base, midgland, and apex are each subdivided into three sections: anterior (a), medial posterior (mp), and lateral posterior (lp). 

    The right and left transition zones (TZ) at prostate base, midgland, and apex are each subdivided into two sections: anterior (a) and posterior (p). 

    The central zone (CZ) is included in the prostate base around the ejaculatory ducts. 

    The anterior fibromuscular stroma (AS) is divided into right/left at the prostate base, midgland, and apex. 

    The seminal vesicles (SV) are divided into right/left. 

    The urethral sphincter (US) is marked in the prostate apex and along the membranous segment of the urethra.

     

    LESION MEASURMENT REPORTING GUIDELINES

    1. The minimum requirement is to report the single largest dimension of a suspicious lesion on an axial image. 
    2. If the largest dimension of a suspicious lesion is on sagittal and/or coronal images, this measurement and imaging plane should be reported.
    3. PZ lesions should be measured on ADC maps. 
    4. TZ lesions should be measured on T2W images. 
    5. If lesion measurements are difficult or compromised on ADC maps (for PZ) or T2W (for TZ), then measurement should be made on sequences that show the lesion outline the best. The image number or series and sequence used for measurement should be indicated.
    6. DCE imaging findings although important, its role in determining PI-RADS v2 assessment categories is secondary to T2W and DWI. DCE serves primarily to help detect significant prostate cancer and not to characterize it.