The NLP Engine Behind
Radiology Intelligence

Aliri NLP is the entity-extraction and ontology-mapping pipeline at the heart of Aliri AI. It transforms free-text radiology reports into structured, ontology-coded clinical data — every entity, every report, automatically.

Looking for the AI analyst layer? See Aliri Discuss.

Four Stages, One Seamless Flow

From raw text to structured intelligence — here's how every report is processed.

Stage 01

Report Ingestion

Connect to any RIS, PACS, or HL7 feed. Aliri normalizes report structure — handling headers, sections, impressions, and addenda — before NLP processing begins.

  • HL7 v2 / FHIR support
  • Real-time streaming or batch import
  • Section segmentation (Findings, Impression, History)
  • Multi-site, multi-modality support

Stage 02

NLP Entity Extraction

A purpose-built medical NLP pipeline identifies clinical entities from free-text radiology reports. The engine handles negation, uncertainty, laterality, and temporal context.

  • Named entity recognition (NER)
  • Negation and uncertainty detection
  • Relationship extraction (finding → anatomy)
  • Context-aware entity linking

Stage 03

Ontology Mapping

Each extracted entity is mapped to RadLex and SNOMED CT concepts using a combination of dictionary lookup, embedding similarity, and rule-based disambiguation.

  • RadLex (RSNA standard)
  • SNOMED CT clinical terminology
  • ICD-10 cross-reference (optional)
  • Confidence scoring per mapping

Stage 04

Structured Output

The result: a fully structured, queryable representation of every report. Each entity carries ontology codes, section context, negation status, and relationship links.

  • JSON / FHIR-compatible output
  • Searchable entity database
  • Cohort builder integration
  • Analytics-ready structured data

What Aliri Extracts

The NLP engine recognizes and classifies nine core entity types from every radiology report.

Anatomy4,200+

right upper lobe, liver, left kidney

Finding3,800+

nodule, mass, effusion, fracture

Disorder/Disease2,500+

pneumonia, cirrhosis, lymphoma

MeasurementDynamic

5mm, 2.3 x 1.8 cm

Modifier600+

stable, increased, new, unchanged

LateralityAuto-detected

right, left, bilateral

PolarityAuto-detected

positive, negative, no evidence of

CertaintyInferred

definite, probable, possible, suspected

RecommendationRule-based

follow-up CT in 6 months, MRI recommended

RadLex + SNOMED CT, Automatically

Every entity is assigned standardized codes from both RadLex and SNOMED CT, enabling cross-system interoperability and research-grade data quality.

High-confidence mapping

Confidence scores on every mapping. Low-confidence results are flagged for review.

Continuous vocabulary updates

Ontology dictionaries are updated with each RadLex and SNOMED release.

Cross-mapping support

Navigate between RadLex and SNOMED via built-in cross-reference tables.

ontology-output.json
{
  "report_id": "RPT-20260329-4182",
  "entities": [
    {
      "text": "hepatic steatosis",
      "type": "FINDING",
      "negated": false,
      "radlex": {
        "id": "RID4566",
        "term": "hepatic steatosis",
        "confidence": 0.97
      },
      "snomed": {
        "id": "197321007",
        "term": "Steatosis of liver",
        "confidence": 0.95
      }
    },
    {
      "text": "right kidney",
      "type": "ANATOMY",
      "radlex": {
        "id": "RID29662",
        "term": "right kidney"
      },
      "snomed": {
        "id": "9846003",
        "term": "Right kidney structure"
      }
    }
  ]
}

Search by Concept, Not by Keyword

Because radiologists describe the same finding in dozens of ways. Aliri searches by ontology concept — so you never miss a match.

Synonym Resolution

Search for "hepatic steatosis" and also find "fatty liver", "steatohepatitis", and "fatty infiltration of liver".

RadLex: RID4566 → 4 synonyms matched

Hierarchical Navigation

Search for "lung nodule" and optionally include all child concepts — ground-glass nodule, calcified nodule, subsolid nodule.

SNOMED hierarchy: 3 levels deep

Complex Queries

Combine anatomy + finding + temporal filters: "all pulmonary embolism findings in the last 90 days, excluding negated mentions."

Supports AND / OR / NOT logic

Aliri NLP structures the data.
Aliri Discuss lets you talk to it.

Once Aliri NLP has structured your reports, Aliri Discuss lets you talk to the result. Ask questions in plain English across clinical findings and operational BI data — no SQL, no dashboards, no waiting — and get cited, grounded answers in seconds.

Explore Aliri Discuss
Ask Aliri Discuss

“Show me CTs with a 5–10mm pulmonary nodule in the last 6 months — and the radiologists whose follow-up rate is below average.”

RadLexSNOMED+ BI

See the platform in action

Schedule a technical demo and see how Aliri processes your radiology reports.

Request a Demo