Pfirrmann · Coluna

Pfirrmann grading of lumbar disc degeneration

vigente

Per-disc lumbar MRI grading that combines T2 structure, nucleus-annulus distinction, signal intensity and disc height; it describes degeneration morphology and does not classify herniation, symptoms or treatment need.

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Escala de categorias

I II III IV V

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Procedência e vigência

Órgão emissor: Pfirrmann et al.
Versão: original five-grade system (2001)
Ano: 2001
Família: léxico
Tipo de lógica: flat
Modalidade: MRI
Fonte primária: Magnetic resonance classification of lumbar intervertebral disc degeneration · doi:10.1097/00007632-200109010-00011
Última verificação: 2026-07-24
Última checagem: 2026-07-24

Lógica de decisão

Forma estruturada (flat). Uma futura calculadora a lê; as categorias abaixo são a superfície legível.

Apply the original four-feature matrix per lumbar disc. Preserve discordant features and version identity; never turn a morphology grade into a pain diagnosis or treatment command.

Mostrar a lógica estruturada (JSON)

{
  "categories": [
    {
      "outcome_code": "I",
      "structure": "homogeneous_bright_white",
      "nucleus_annulus_distinction": "clear",
      "T2_signal": "hyperintense_and_isointense_to_CSF",
      "disc_height": "normal"
    },
    {
      "outcome_code": "II",
      "structure": "inhomogeneous_with_or_without_horizontal_bands",
      "nucleus_annulus_distinction": "clear",
      "T2_signal": "hyperintense_and_isointense_to_CSF",
      "disc_height": "normal"
    },
    {
      "outcome_code": "III",
      "structure": "inhomogeneous_gray",
      "nucleus_annulus_distinction": "unclear",
      "T2_signal": "intermediate",
      "disc_height": "normal_to_slightly_decreased"
    },
    {
      "outcome_code": "IV",
      "structure": "inhomogeneous_gray_to_black",
      "nucleus_annulus_distinction": "lost",
      "T2_signal": "intermediate_to_hypointense",
      "disc_height": "normal_to_moderately_decreased"
    },
    {
      "outcome_code": "V",
      "structure": "inhomogeneous_black",
      "nucleus_annulus_distinction": "lost",
      "T2_signal": "hypointense",
      "disc_height": "collapsed_disc_space"
    }
  ],
  "applicability": {
    "use_for": "Gross morphologic grading of each lumbar intervertebral disc on routine midsagittal T2-weighted MRI.",
    "classification_unit": "one_lumbar_intervertebral_disc_level",
    "required_inputs": [
      "disc_level",
      "diagnostic_midsagittal_T2_image",
      "disc_structure",
      "nucleus_annulus_distinction",
      "T2_signal_relative_to_CSF",
      "disc_height"
    ],
    "outside_scope": [
      "disc_bulge_protrusion_extrusion_or_sequestration",
      "annular_fissure",
      "Modic_endplate_change",
      "canal_or_foraminal_stenosis",
      "pain_generator_identification",
      "treatment_selection"
    ]
  },
  "acquisition_and_quality_gate": {
    "primary_sequence": "Routine T2-weighted midsagittal lumbar MRI, matching the sequence used to develop and test the original system.",
    "level_rule": "Identify and grade every requested disc level separately; do not transfer a grade from one level to another.",
    "adequacy_rule": "If structure, T2 signal, nucleus-annulus distinction or height cannot be judged because the sequence, plane, artifact or coverage is inadequate, return no definitive grade and name the missing feature.",
    "anatomy_variant_guard": "A congenitally small or transitional lumbosacral disc can have reduced height with relatively preserved signal. Do not call Grade V from height alone when the morphology suggests hypoplasia or segmentation variation."
  },
  "feature_model": {
    "structure": "Homogeneous versus inhomogeneous internal morphology, including whether horizontal bands are present.",
    "distinction": "Visibility of the boundary between nucleus pulposus and annulus fibrosus: clear, unclear or lost.",
    "signal": "Qualitative T2 signal of the disc, with CSF as the original high-signal reference: hyperintense, intermediate or hypointense.",
    "height": "Qualitative disc-space height: normal, slightly decreased, moderately decreased or collapsed; the original five-grade system does not define percentage cutoffs.",
    "combined_rule": "Assign the grade from the complete four-feature pattern rather than from darkness, height or any single feature in isolation."
  },
  "classification_algorithm": [
    {
      "if_all": [
        "homogeneous_bright_white",
        "clear_nucleus_annulus_boundary",
        "T2_hyperintense_isointense_to_CSF",
        "normal_height"
      ],
      "output_code": "I"
    },
    {
      "if_all": [
        "inhomogeneous_with_or_without_horizontal_bands",
        "clear_nucleus_annulus_boundary",
        "T2_hyperintense_isointense_to_CSF",
        "normal_height"
      ],
      "output_code": "II"
    },
    {
      "if_all": [
        "inhomogeneous_gray",
        "unclear_nucleus_annulus_boundary",
        "intermediate_T2_signal",
        "normal_to_slightly_decreased_height"
      ],
      "output_code": "III"
    },
    {
      "if_all": [
        "inhomogeneous_gray_to_black",
        "lost_nucleus_annulus_boundary",
        "intermediate_to_hypointense_T2_signal",
        "normal_to_moderately_decreased_height"
      ],
      "output_code": "IV"
    },
    {
      "if_all": [
        "inhomogeneous_black",
        "lost_nucleus_annulus_boundary",
        "hypointense_T2_signal",
        "collapsed_disc_space"
      ],
      "output_code": "V"
    }
  ],
  "boundary_and_conflict_rules": {
    "I_versus_II": "Both retain high T2 signal, a clear nucleus-annulus boundary and normal height; internal homogeneity separates I from the inhomogeneity or horizontal bands of II.",
    "II_versus_III": "Loss of high CSF-like signal and transition from a clear to an unclear nucleus-annulus boundary support III.",
    "III_versus_IV": "Disc height overlaps and is not a reliable discriminator; use the transition from gray/unclear to gray-black/lost distinction together with signal loss.",
    "IV_versus_V": "Grade V requires a collapsed disc space in addition to a black hypointense disc and lost distinction. A dark disc with preserved or only moderately reduced height remains IV.",
    "discordant_features": "When the four features straddle adjacent grades, preserve the full feature vector and state the adjacent-grade uncertainty; do not average ordinal labels or force a grade from one feature."
  },
  "version_boundary": {
    "original_map": "This decision map is the five-grade Pfirrmann 2001 system.",
    "modified_map": "The later modified Pfirrmann system uses eight grades and explicit height-reduction bands; those grade numbers and thresholds are a separate derivative and must not be backported into this five-grade map.",
    "fractional_or_AI_grades": "Fractional or continuous model outputs are not official grades in the original system. Convert only with an explicitly validated mapping and retain the native model output."
  },
  "separate_reporting_requirements": [
    "Report disc herniation morphology and nerve-root effect separately from the Pfirrmann grade.",
    "Report Modic marrow change, endplate defect, stenosis, spondylolisthesis, facet disease and postoperative findings separately.",
    "Correlate degenerative morphology with symptoms and examination; the grade does not identify a pain generator."
  ],
  "management_and_risk_context": {
    "management_rule": "No Pfirrmann grade independently prescribes observation, injection, surgery or follow-up. Management depends on symptoms, neurologic findings, instability, stenosis, herniation and the broader clinical context.",
    "risk_rule": "The ordinal grade expresses morphologic degeneration severity only. The original system does not provide a per-grade probability of pain, progression, neurologic deficit or future intervention.",
    "research_rule": "Use exact per-level grades and the original version when comparing studies; do not mix the five-grade and eight-grade systems as if their numbers were interchangeable."
  },
  "output_contract": [
    "lumbar_disc_level",
    "sequence_and_technical_adequacy",
    "structure_feature",
    "nucleus_annulus_distinction",
    "T2_signal_relative_to_CSF",
    "disc_height_category",
    "Pfirrmann_grade_I_to_V_or_adjacent_grade_uncertainty",
    "separate_herniation_stenosis_endplate_and_postoperative_findings",
    "no_treatment_or_pain_inference_from_grade_alone"
  ],
  "missing_input_behavior": [
    "If the midsagittal T2 image is absent or nondiagnostic, do not assign a definitive Pfirrmann grade.",
    "If disc height is unknown in a dark disc, do not distinguish IV from V; report IV-versus-V uncertainty and request a height assessment.",
    "If structure or nucleus-annulus distinction is not visible, do not classify from signal intensity alone.",
    "If a transitional or hypoplastic disc is suspected, state that variant before interpreting reduced height as degeneration."
  ],
  "interpretation_limits": [
    "The scale was developed as a reliable gross-morphology classification, not a diagnosis of symptomatic discogenic pain.",
    "It does not encode annular fissures, focal herniation, nerve compression, vertebral endplate changes or segmental instability.",
    "Its qualitative height terms have no official percentage cutoffs in the original five-grade publication."
  ],
  "source_locator": "Pfirrmann et al., Spine 2001;26:1873-1878, PMID 11568697, DOI 10.1097/00007632-200109010-00011, Table 1 for the four-feature grade matrix; Methods for midsagittal T2 application; Results and Discussion for reliability, feature-boundary disagreements, height use and the transitional-disc pitfall."
}

Categorias num relance

Cat.	Significado	Conduta	Risco	Fonte
I	Grade I Grade I: homogeneous, bright-white disc structure; a clear nucleus pulposus-annulus fibrosus distinction; T2 signal hyperintense and isointense to cerebrospinal fluid; and normal intervertebral-disc height.	Report Grade I with its four supporting features at the specific lumbar level. The grade does not direct treatment; correlate symptoms and any intervention decision with the neurologic examination and separate structural findings.	This is the least degenerated morphology in the original five-grade system, but it supplies no probability of pain, future degeneration, neurologic deficit or need for intervention and does not exclude another pain generator.	okfonte Pfirrmann et al., Spine 2001;26:1873-1878, Table 1, Grade I; Methods specify grading on T2-weighted midsagittal images; Discussion defines the system as gross disc morphology rather than a symptom or treatment scale.
II	Grade II Grade II: inhomogeneous disc structure, with or without horizontal bands; the nucleus-annulus distinction remains clear; T2 signal remains hyperintense and isointense to cerebrospinal fluid; and disc height remains normal.	Document the inhomogeneity or horizontal bands while preserving the normal height and high signal that distinguish Grade II. No surveillance, procedure or operation follows from Grade II alone; correlate clinically and report other abnormalities separately.	Grade II denotes early morphologic change relative to Grade I, not a calibrated risk stratum. The original publication gives no per-grade probability of symptoms, progression, work limitation or later treatment.	okfonte Pfirrmann et al., Spine 2001;26:1873-1878, Table 1, Grade II; Results and Discussion describe reliability and note that disagreements were relatively frequent at the I-II boundary.
III	Grade III Grade III: inhomogeneous gray disc structure; an unclear nucleus-annulus distinction; intermediate T2 signal; and disc height that is normal to slightly decreased.	Report every defining feature and the lumbar level, then describe herniation, stenosis, endplate change and neural effect independently. Grade III alone neither establishes a symptomatic pain generator nor selects conservative or operative care.	Grade III is an intermediate morphologic category. The five-grade scale does not attach a patient-specific likelihood of pain, progression, instability, neurologic compromise or intervention to this label.	okfonte Pfirrmann et al., Spine 2001;26:1873-1878, Table 1, Grade III; Discussion states that height does not discriminate Grade III from Grade IV and that the system assesses gross morphology.
IV	Grade IV Grade IV: inhomogeneous gray-to-black disc structure; loss of the nucleus-annulus distinction; intermediate-to-hypointense T2 signal; and disc height ranging from normal to moderately decreased, without the collapsed space required for Grade V.	Describe the advanced morphologic features and preserve the actual disc-height category. Treatment still depends on symptoms, neurologic findings, instability, herniation and stenosis; a dark Grade IV disc is not by itself an indication for a procedure.	Grade IV denotes advanced degeneration morphology but is not a prognosis. The original system does not quantify pain, progression, nerve injury or surgical probability, and height overlap with Grade III limits single-feature inference.	okfonte Pfirrmann et al., Spine 2001;26:1873-1878, Table 1, Grade IV; Discussion states that height is not discriminative for III versus IV and is important for distinguishing IV from V.
V	Grade V Grade V: inhomogeneous black disc structure; lost nucleus-annulus distinction; hypointense T2 signal; and a collapsed disc space. All four features should support end-stage morphology rather than assigning V from reduced height alone.	Report collapse and the complete feature pattern, then separately describe neural compression, deformity, instability and postoperative status. Grade V alone does not mandate surgery; exclude congenital or transitional-disc hypoplasia when height and signal conflict.	This is the most advanced morphology in the original five-grade system, but it remains an ordinal imaging label without an individual probability of pain, disability, neurologic deficit, progression or treatment response.	okfonte Pfirrmann et al., Spine 2001;26:1873-1878, Table 1, Grade V; Discussion explains height as the IV-V discriminator and describes a sacralized transitional level misgraded V when marked smallness conflicted with Grade-II-like signal.

Referências cruzadas

fronteira compartilhadaModic. Modic vertebral endplate marrow changesComplementary to Modic endplate changes when grading lumbar degeneration.

Histórico de versões

Data	Evento	Detalhe	Situação
2001-09-01	published	Pfirrmann disc degeneration grading published in Spine.	confirmado

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