Genant visual semiquantitative vertebral fracture grading

{
  "categories": [
    {
      "outcome_code": "0",
      "label": "normal",
      "fracture_status": "no_visual_fracture",
      "height_reduction": "below_20_percent_only_if_morphology_is_normal"
    },
    {
      "outcome_code": "0.5",
      "label": "borderline_or_questionable",
      "fracture_status": "deformation_present_but_not_clearly_grade_1",
      "role": "optional_Genant_borderline_category_not_a_definite_fracture_grade"
    },
    {
      "outcome_code": "1",
      "label": "mild",
      "fracture_status": "definite_visual_fracture",
      "height_reduction_any_of_anterior_middle_or_posterior": "approximately_20_to_25_percent",
      "projected_area_reduction": "approximately_10_to_20_percent"
    },
    {
      "outcome_code": "2",
      "label": "moderate",
      "fracture_status": "definite_visual_fracture",
      "height_reduction_any_of_anterior_middle_or_posterior": "approximately_26_to_40_percent",
      "projected_area_reduction": "approximately_21_to_40_percent"
    },
    {
      "outcome_code": "3",
      "label": "severe",
      "fracture_status": "definite_visual_fracture",
      "height_reduction_any_of_anterior_middle_or_posterior": "greater_than_40_percent",
      "projected_area_reduction": "greater_than_40_percent"
    }
  ],
  "applicability": {
    "use_for": "Visual semiquantitative identification and severity grading of vertebral fractures, one vertebral body at a time, primarily on lateral thoracic and lumbar radiographs or densitometric vertebral fracture assessment.",
    "classification_unit": "one_identified_vertebral_body_from_T4_through_L4",
    "required_inputs": [
      "vertebral_level",
      "diagnostic_lateral_view_or_sagittal_reformation",
      "technical_evaluability",
      "anterior_middle_and_posterior_height",
      "projected_area_or_visual_area_loss",
      "endplate_and_cortex_morphology",
      "adjacent_vertebral_context",
      "alternative_deformity_assessment"
    ],
    "outside_scope": [
      "acute_fracture_age_without_MRI_or_prior_imaging",
      "etiology_from_grade_alone",
      "spinal_instability",
      "neurologic_compression",
      "bone_mineral_density_diagnosis",
      "treatment_selection",
      "individual_future_fracture_probability"
    ]
  },
  "modality_and_quality_gate": {
    "original_method": "Visual assessment on standardized lateral thoracic and lumbar radiographs from T4 through L4, without requiring direct caliper measurement for every vertebra.",
    "VFA_rule": "For densitometric VFA, the 2023 ISCD positions identify Genant visual semiquantitative assessment as the clinical technique of choice. Diagnosis remains visual; morphometry alone is unreliable.",
    "CT_rule": "Sagittal CT reformations can reveal and characterize vertebral deformity, but the report must retain CT as the modality and apply the visual fracture and differential-diagnosis gate before using height thresholds.",
    "adequacy_rule": "Mark a vertebra unevaluable when rotation, projection, overlap, poor exposure, severe scoliosis, hardware or limited coverage prevents confident identification of its endplates and height. Never assign Grade 0 to an unseen vertebra.",
    "comparison_rule": "For incident change, compare technically similar studies side by side and confirm vertebral numbering before assigning a new or increased grade."
  },
  "visual_diagnosis_before_morphometry": {
    "core_rule": "First decide whether the contour and endplate or cortical change is consistent with fracture. Use height and area loss to grade a visually credible fracture, not to convert every short vertebra into osteoporosis.",
    "fracture_features": [
      "endplate_depression_or_loss_of_parallelism",
      "anterior_cortex_buckling_or_interruption",
      "wedge_biconcave_or_crush_configuration_with_credible_fracture_morphology",
      "change_from_prior_or_adjacent_expected_shape"
    ],
    "normal_variation_guard": "Midthoracic vertebrae and the thoracolumbar junction can be physiologically wedged, and lower lumbar bodies may be mildly biconcave. Compare with adjacent levels and expected regional anatomy.",
    "nonfracture_differential": [
      "degenerative_remodeling",
      "Scheuermann_disease",
      "congenital_or_developmental_variant",
      "prior_high_energy_trauma",
      "neoplastic_deformity",
      "Paget_disease",
      "infection",
      "postoperative_or_treatment_change"
    ],
    "subthreshold_fracture_rule": "A definite endplate or cortical fracture can be visually recognized with less than 20 percent height loss. Describe it as a fracture below the Grade 1 morphometric threshold rather than mislabeling it Grade 0 or rounding it to Grade 1."
  },
  "severity_assignment_algorithm": [
    {
      "if": "normal_expected_shape_without_visual_fracture_or_pathologic_deformity",
      "output_code": "0"
    },
    {
      "if": "some_deformation_but_not_confidently_a_definite_grade_1_fracture",
      "output_code": "0.5"
    },
    {
      "if": "definite_visual_fracture_with_approximately_20_to_25_percent_loss_in_any_height_and_approximately_10_to_20_percent_area_loss",
      "output_code": "1"
    },
    {
      "if": "definite_visual_fracture_with_approximately_26_to_40_percent_loss_in_any_height_and_approximately_21_to_40_percent_area_loss",
      "output_code": "2"
    },
    {
      "if": "definite_visual_fracture_with_greater_than_40_percent_loss_in_height_and_projected_area",
      "output_code": "3"
    }
  ],
  "morphology_and_measurement_model": {
    "anterior_height": "Anterior vertebral-body height, interpreted against posterior height, adjacent vertebrae and expected regional shape.",
    "middle_height": "Central vertebral-body height; predominant loss supports a biconcave deformity.",
    "posterior_height": "Posterior vertebral-body height; substantial posterior and generalized loss supports a crush deformity.",
    "projected_area": "Visual or measured lateral projected vertebral-body area. The original system includes area reduction even though later clinical use often emphasizes height.",
    "grade_rule": "Use the greatest credible loss among anterior, middle and posterior heights together with area and morphology. Preserve exact measurements and any threshold discordance.",
    "shape_rule": "Report wedge, biconcave or crush morphology separately. Shape is not tied to a particular severity grade and does not replace the 0-3 score.",
    "area_height_conflict": "If height and area suggest different grades, return the supported range and expert review rather than selecting the more severe number silently."
  },
  "borderline_and_serial_rules": {
    "grade_0_5": "Grade 0.5 is an optional borderline designation sometimes used for a deformed vertebra that cannot be clearly assigned Grade 1. It must not be presented as a definite mild fracture or collapsed into Grade 0 without explanation.",
    "incident_fracture": "A new incident semiquantitative fracture generally requires progression by a full grade or from a previously questionable 0.5 vertebra to a definite fracture on comparable serial imaging.",
    "remodeling_guard": "Settling or remodeling of a known fracture can reduce height without representing a distinct new fracture. Correlate symptoms, interval and marrow edema or fracture line when acuity matters.",
    "multi_level_rule": "Grade every evaluable level independently and list unevaluable levels. Do not average grades across the spine as a patient-level severity class."
  },
  "current_ISCD_context": {
    "endorsed_use": "ISCD 2023 retains Genant visual semiquantitative assessment as the clinical technique of choice for diagnosing vertebral fracture on VFA and allows morphometry to confirm severity.",
    "follow_up_imaging_triggers": [
      "lesion_not_attributable_to_a_benign_cause",
      "vertebral_deformity_with_relevant_malignancy_history",
      "equivocal_fracture",
      "unidentifiable_vertebra_between_T7_and_L4",
      "sclerotic_lytic_or_other_nonosteoporotic_feature"
    ],
    "report_elements": [
      "technical_quality",
      "unevaluable_levels",
      "deformed_levels",
      "whether_each_deformity_is_consistent_with_fracture",
      "unexplained_vertebral_or_extravertebral_pathology"
    ]
  },
  "management_and_risk_context": {
    "management_rule": "A confirmed vertebral fragility fracture should be clearly reported and can prompt osteoporosis and secondary-cause evaluation under local clinical guidance, but Genant grade alone does not select medication, vertebral augmentation, surgery or follow-up interval.",
    "risk_rule": "Prevalent vertebral fractures are associated with future fracture and morbidity, but the semiquantitative grade is not a patient-specific risk calculator. Integrate age, BMD, prior fractures, glucocorticoids and a validated clinical risk model.",
    "acuity_rule": "The morphology grade does not establish acute versus chronic. Use marrow edema, fracture line, soft-tissue findings, prior imaging and symptoms when acuity changes care."
  },
  "output_contract": [
    "modality_view_and_technical_adequacy",
    "every_evaluable_and_unevaluable_level_T4_to_L4",
    "visual_fracture_or_nonfracture_deformity_assessment",
    "anterior_middle_posterior_height_and_projected_area_loss",
    "wedge_biconcave_or_crush_shape",
    "Genant_0_0_5_1_2_3_or_ungraded_subthreshold_fracture",
    "comparison_with_prior_and_change_in_grade",
    "alternative_pathologic_degenerative_congenital_or_traumatic_cause",
    "acuity_features_reported_separately",
    "osteoporosis_evaluation_flag_without_autonomous_treatment"
  ],
  "missing_input_behavior": [
    "If a vertebral level is not visible or not confidently numbered, mark it unevaluable rather than Grade 0.",
    "If morphometry shows height loss but visual fracture morphology is absent, report a nonfracture deformity or unresolved cause instead of assigning a Genant fracture automatically.",
    "If deformation is visible but does not clearly meet Grade 1, preserve Grade 0.5 or explicit borderline uncertainty.",
    "If a definite endplate or cortical fracture has less than 20 percent height loss, describe the subthreshold fracture and do not force Grade 0 or 1.",
    "If height and area thresholds conflict, retain the measurements and adjacent-grade range for expert adjudication."
  ],
  "interpretation_limits": [
    "The original validation cohort comprised postmenopausal women and the system requires training and standardized visual interpretation, especially for Grade 0.5-1.",
    "The grade does not diagnose osteoporosis etiology, fracture acuity, instability, malignancy or neurologic compromise.",
    "Projection, normal regional shape and degenerative remodeling can create false mild fractures; morphometry without visual adjudication is insufficient."
  ],
  "supporting_sources": [
    {
      "role": "primary_method",
      "citation": "Genant et al. J Bone Miner Res. 1993;8:1137-1148",
      "doi": "10.1002/jbmr.5650080915",
      "pmid": "8237484"
    },
    {
      "role": "open_visual_method_and_differential",
      "citation": "Grigoryan et al. Eur Spine J. 2003;12 Suppl 2:S104-S112",
      "doi": "10.1007/s00586-003-0613-0",
      "pmcid": "PMC3591834"
    },
    {
      "role": "current_VFA_position",
      "citation": "International Society for Clinical Densitometry 2023 Official Adult Positions",
      "url": "https://iscd.org/official-positions-2023/"
    }
  ],
  "source_locator": "Genant et al. 1993, PMID 8237484, DOI 10.1002/jbmr.5650080915, original semiquantitative method; Grigoryan et al. 2003, PMC3591834, visual SQ thresholds, Grade 0.5, morphology, differential diagnosis and serial assessment; ISCD 2023 Official Adult Positions, Methods for Defining and Reporting Fractures on VFA and follow-up imaging indications."
}