Table 2.
PI-RADS v2 scoring systems.
| Score criteria |
|---|
| T2WI for peripheral zone |
| 1. Uniform high signal intensity |
| 2. Linear, wedge-shaped, or geographic areas of lower SI, usually not well demarcated |
| 3. Heterogeneous signal intensity or non-circumscribed, rounded, moderate hypointensity. Or other not in categories 1/2 or 4/5 [Intermediate, not 1/2 or 4/5] |
| 4. Circumscribed, homogeneous moderate hypointense focus/mass confined to prostate and <1.5 cm in greatest dimension |
| [No size stated] |
| 5. Same as 4 but ≥1.5 cm in greatest dimension or definite ECE/invasive behaviour |
| [Broad >1.5 cm capsule contact] |
| T2WI for transition zone |
| 1. Heterogeneous intermediate SI |
| [Used terms well-defined margins and “organised chaos”] |
| 2. Circumscribed hypointense or heterogeneous encapsulated nodule(s) (BPH) |
| [Used well-marginated] |
| 3. Heterogeneous signal intensity with obscured margins. Or other not in categories 1/2 or 4/5 |
| [Intermediate, not 1/2 or 4/5] |
| 4. Lenticular or non-circumscribed, homogeneous, moderately hypointense, and <1.5 cm in greatest dimension |
| [No size stated. Used term “erased charcoal sign”] |
| 5. Same as 4, but ≥ 1.5 cm in greatest dimension or definite ECE /invasive behaviour |
| [Involving the anterior fibromuscular stroma or the anterior horn of the PZ] |
| DWI |
| 1. No abnormality (i.e. normal) on ADC and high b-value DWI |
| 2. Indistinct hypointense on ADC |
| [Also: diffuse hyper SI on ≥b=800 image; no focal features] |
| 3. Focal mildly/moderately hypointense on ADC and isointense/mildly hyperintense on high b-value DWI |
| [Intermediate, not 1/2 or 4/5] |
| 4. Focal markedly hypointense on ADC and markedly hyperintense on high b-value DWI; <1.5 cm in greatest dimension |
| [Iso-intense on high b-value. No size stated] |
| 5. Same as 4 but ≥1.5 cm in greatest dimension or definite ECE/invasive behaviour |
| [Focal, hyper SI on the high b-value images with reduced ADC] |
| Dynamic contrast-enhanced MRI |
| −No early enhancement OR |
| Diffuse enhancement not corresponding to a focal finding on T2 and/or DWI OR |
| Focal enhancement corresponding to a lesion demonstrating features of BPH on T2WI |
| + Focal AND |
| Earlier than or contemporaneously with enhancement of adjacent normal prostatic tissues AND
Corresponds to suspicious finding on T2 and/or DWI |
Differences from version 1 stated in parentheses.
PI-RADS v2, Prostate Imaging—Reporting and Data System version 2; T2W1, T2-weighted imaging; SI, signal intensity; ECE, extra-capsular extension; BPH, benign prostatic hypertrophy; ADC, apparent diffusion coefficient; DWI, diffusion-weighted imaging; MRI, magnetic resonance imaging.