Prostate Imaging Reporting And Data System (PI-RADS)

PI-RADS is designed to improve focal lesion detection, localization, characterization, and risk stratification in patients with suspected cancer and consists of technical recommendation for MRI acquisition and a scoring system for image interpretation. PI-RADS uses a scale of 1–5 to report the overall probability of clinically significant prostate cancer on multiparametric MRI (mpMRI). The use of PI-RADS is limited to treatment naive patients and it should not be used for staging, assessment of treatment outcome, recurrence, or progression during surveillance.

Continue reading

Diagnostic Criteria of Infarction in MRI of the Brain in Acute Stroke

Acute: Subtle low signal (hypointense) on T1, often difficult to see at this stage, and high signal (hyperintense) on spin density and/or T2-weighted and proton density-weighted images starting 8 h after onset; should follow vascular distribution. Mass effect maximal at 24 h, sometimes starting 2 h after onset, even in the absence of parenchymal signal changes. No parenchymal enhancement with paramagnetic contrast agent. Territorial intravascular paramagnetic contrast enhancement of “slow-flow” arteries in hyperacute infarcts; at 48 h, parenchymal and meningeal enhancement can be expected.

Continue reading

Diagnostic Criteria of Hemorrhage in MRI of the Brain

The imaging characteristics of blood on MRI can be variable:

Continue reading