Use DWI/ADC as the dominant sequence in the peripheral zone and T2W in the transition zone. DCE only upgrades a peripheral-zone DWI score 3 to overall category 4 when positive; category and clinical management are separate decisions.
{
"applicability": {
"purpose": "Detect, localize, characterize, and risk-stratify clinically significant prostate cancer on pretreatment prostate MRI.",
"clinically_significant_cancer": "Gleason score >=3+4 (grade group >=2), and/or tumor volume >=0.5 cc, and/or extraprostatic extension.",
"assessment_inputs": "Assign the category from mpMRI findings only; do not incorporate PSA, digital rectal examination, clinical history, or planned treatment into the imaging category."
},
"axes": {
"zone": [
"peripheral",
"transition"
],
"dominant_sequence": {
"peripheral": "DWI_ADC",
"transition": "T2W"
},
"DCE": [
"positive",
"negative",
"inadequate_or_absent"
],
"component_quality": [
"diagnostic",
"X_inadequate_or_absent"
]
},
"sequence_scores": {
"DWI_ADC": [
{
"score": 1,
"finding": "No abnormality on ADC or high-b-value DWI."
},
{
"score": 2,
"finding": "Linear or wedge-shaped ADC hypointensity and/or linear or wedge-shaped high-b-value DWI hyperintensity."
},
{
"score": 3,
"finding": "Focal abnormality discrete from background with ADC hypointensity and/or high-b-value DWI hyperintensity, but not marked on both."
},
{
"score": 4,
"finding": "Focal markedly low ADC and markedly high high-b-value DWI signal, greatest dimension <15 mm."
},
{
"score": 5,
"finding": "Same diffusion pattern as score 4 with greatest dimension >=15 mm, or definite extraprostatic extension/invasive behavior."
}
],
"T2W_transition_zone": [
{
"score": 1,
"finding": "Normal-appearing transition zone or a round completely encapsulated typical nodule."
},
{
"score": 2,
"finding": "Mostly encapsulated nodule, homogeneous circumscribed nodule without encapsulation, or homogeneous mildly hypointense area between nodules."
},
{
"score": 3,
"finding": "Heterogeneous signal with obscured margins, including findings that do not qualify as 2, 4, or 5."
},
{
"score": 4,
"finding": "Lenticular or noncircumscribed homogeneous moderately T2-hypointense focus, greatest dimension <15 mm."
},
{
"score": 5,
"finding": "Same morphology as score 4 with greatest dimension >=15 mm, or definite extraprostatic extension/invasive behavior."
}
],
"T2W_peripheral_zone": [
{
"score": 1,
"finding": "Uniform T2 hyperintense signal (normal)."
},
{
"score": 2,
"finding": "Linear or wedge-shaped hypointensity, or diffuse mild hypointensity, usually with indistinct margins."
},
{
"score": 3,
"finding": "Heterogeneous signal or a noncircumscribed rounded moderately hypointense focus that does not qualify as 2, 4, or 5."
},
{
"score": 4,
"finding": "Circumscribed homogeneous moderately T2-hypointense focus confined to the prostate, greatest dimension <15 mm."
},
{
"score": 5,
"finding": "Same morphology as score 4 with greatest dimension >=15 mm, or definite extraprostatic extension/invasive behavior."
}
],
"DCE": {
"positive": "Focal enhancement earlier than or contemporaneous with adjacent normal prostate that corresponds to a suspicious T2W and/or DWI finding.",
"negative": "No early enhancement, or diffuse/noncorresponding enhancement, or focal enhancement matching a T2W feature of BPH."
}
},
"categories": [
"1",
"2",
"3",
"4",
"5"
],
"cells": {
"peripheral_zone": [
{
"DWI_ADC_score": 1,
"DCE": "any",
"outcome_code": "1"
},
{
"DWI_ADC_score": 2,
"DCE": "any",
"outcome_code": "2"
},
{
"DWI_ADC_score": 3,
"DCE": "negative",
"outcome_code": "3"
},
{
"DWI_ADC_score": 3,
"DCE": "positive",
"outcome_code": "4"
},
{
"DWI_ADC_score": 4,
"DCE": "any",
"outcome_code": "4"
},
{
"DWI_ADC_score": 5,
"DCE": "any",
"outcome_code": "5"
}
],
"transition_zone": [
{
"T2W_score": 1,
"DWI_ADC_score": "any",
"outcome_code": "1"
},
{
"T2W_score": 2,
"DWI_ADC_score": "<=3",
"outcome_code": "2"
},
{
"T2W_score": 2,
"DWI_ADC_score": ">=4",
"outcome_code": "3"
},
{
"T2W_score": 3,
"DWI_ADC_score": "<=4",
"outcome_code": "3"
},
{
"T2W_score": 3,
"DWI_ADC_score": 5,
"outcome_code": "4"
},
{
"T2W_score": 4,
"DWI_ADC_score": "any",
"outcome_code": "4"
},
{
"T2W_score": 5,
"DWI_ADC_score": "any",
"outcome_code": "5"
}
]
},
"inadequate_components": {
"DWI_ADC_X": {
"warning": "Usually repeat DWI if the cause can be remedied; otherwise acknowledge the substantial limitation in the report.",
"fallback_cells": [
{
"T2W_score": 1,
"DCE": "any",
"outcome_code": "1"
},
{
"T2W_score": 2,
"DCE": "any",
"outcome_code": "2"
},
{
"T2W_score": 3,
"DCE": "negative",
"outcome_code": "3"
},
{
"T2W_score": 3,
"DCE": "positive",
"outcome_code": "4"
},
{
"T2W_score": 4,
"DCE": "any",
"outcome_code": "4"
},
{
"T2W_score": 5,
"DCE": "any",
"outcome_code": "5"
}
]
},
"DCE_X": {
"peripheral_zone": "Determine the category from the DWI assessment category.",
"transition_zone": "Use the standard T2W-by-DWI transition-zone matrix."
},
"DWI_ADC_and_DCE_X": "Limit assessment to staging for extraprostatic extension; do not infer a lesion PI-RADS category from missing components."
},
"management_scope": {
"rule": "PI-RADS v2.1 does not prescribe management; decisions must incorporate laboratory and clinical history, local expertise, and standards of care.",
"category_1_2": "The document says biopsy should not be based on PI-RADS 1 or 2 alone.",
"category_3": "Biopsy may or may not be appropriate depending on factors outside mpMRI.",
"category_4_5": "Biopsy should be considered, but the final decision remains clinical.",
"forbidden_inference": "Do not invent PSA-density cutoffs, follow-up intervals, or a biopsy mandate from PI-RADS alone."
},
"source_locator": "ACR/ESUR/AdMeTech PI-RADS v2.1 (2019), assessment categories and management scope p 10; zone matrices p 11; inadequate-component tables pp 15-16; T2W scoring p 18; DWI scoring pp 20-21; DCE definition and caveats pp 22-23."
}