<p class="first" id="d11514112e266">The Prostate Imaging Reporting and Data System
version 2 (PI-RADS v2) was developed
with a consensus-based process using a combination of published data, and expert observations
and opinions. In the short time since its release, numerous studies have validated
the value of PI-RADS v2 but, as expected, have also identified a number of ambiguities
and limitations, some of which have been documented in the literature with potential
solutions offered. To address these issues, the PI-RADS Steering Committee, again
using a consensus-based process, has recommended several modifications to PI-RADS
v2, maintaining the framework of assigning scores to individual sequences and using
these scores to derive an overall assessment category. This updated version, described
in this article, is termed PI-RADS v2.1. It is anticipated that the adoption of these
PI-RADS v2.1 modifications will improve inter-reader variability and simplify PI-RADS
assessment of prostate magnetic resonance imaging even further. Research on the value
and limitations on all components of PI-RADS v2.1 is strongly encouraged.
</p>