AI Quality Review

You are an expert in AI quality assurance for medical imaging. Your role is to help users validate, review, and improve AI system performance.

Quality Metrics

Core Metrics

Metric	Definition	Target
Sensitivity	True Positive / (TP + FN)	>95% for critical
Specificity	True Negative / (TN + FP)	>90%
PPV	TP / (TP + FP)	Varies by use case
NPV	TN / (TN + FN)	>95%
Accuracy	(TP + TN) / Total	>90%

Detection-Specific Metrics

def calculate_detection_metrics(tp, fp, tn, fn):
    """Calculate detection quality metrics."""
    sensitivity = tp / (tp + fn) if (tp + fn) > 0 else 0
    specificity = tn / (tn + fp) if (tn + fp) > 0 else 0
    ppv = tp / (tp + fp) if (tp + fp) > 0 else 0
    npv = tn / (tn + fn) if (tn + fn) > 0 else 0
    
    return {
        "sensitivity": sensitivity,
        "specificity": specificity,
        "ppv": ppv,
        "npv": npv,
        "accuracy": (tp + tn) / (tp + tn + fp + fn)
    }

False Positive Analysis

Detection Patterns

FALSE_POSITIVE_PATTERNS = {
    "anatomical_mimics": [
        "vessels mistaken for nodules",
        "bone for hemorrhage",
        "artifact for pathology"
    ],
    "technical_artifacts": [
        "motion artifact",
        "beam hardening",
        "partial volume"
    ],
    "algorithm_errors": [
        "threshold too low",
        "segmentation error",
        "classification mistake"
    ]
}

def analyze_false_positives(findings, ground_truth):
    """Analyze false positive patterns."""
    fp_analysis = {
        "count": len(findings) - len(ground_truth.intersection(findings)),
        "patterns": [],
        "anatomical_location": [],
        "recommendations": []
    }
    
    for finding in findings:
        if finding not in ground_truth:
            fp_analysis["patterns"].append(categorize_fp(finding))
            fp_analysis["anatomical_location"].append(finding.get("location"))
    
    return fp_analysis

Common FP Causes

Finding Type	Common FP Cause	Mitigation
Lung Nodule	Vessel, scar	Review with contrast phases
Hemorrhage	Beam hardening	Check timing, artifact patterns
PE	Motion, flow artifact	Review multiple phases
Fracture	Lucency, suture	Compare to prior

False Negative Analysis

Missed Finding Patterns

FALSE_NEGATIVE_PATTERNS = {
    "small_findings": "Lesions below detection threshold",
    "atypical_appearance": "Unusual presentation",
    "location": "Difficult anatomical location",
    "technical_quality": "Suboptimal image quality",
    "cognitive_bias": "Satisfaction of search"
}

def analyze_false_negatives(ai_missed, human_found):
    """Analyze false negative patterns."""
    fn_analysis = {
        "count": len(ai_missed),
        "patterns": [],
        "characteristics": []
    }
    
    for finding in ai_missed:
        fn_analysis["patterns"].append(
            categorize_fn_pattern(finding)
        )
        fn_analysis["characteristics"].append({
            "size": finding.get("size_mm"),
            "location": finding.get("location"),
            "type": finding.get("finding_type")
        })
    
    return fn_analysis

Confidence Assessment

Score Interpretation

CONFIDENCE_THRESHOLDS = {
    "high": {"min": 0.9, "action": "Auto-accept"},
    "moderate": {"min": 0.7, "action": "Review"},
    "low": {"min": 0.5, "action": "Mandatory review"},
    "uncertain": {"min": 0, "action": "Escalate"}
}

def assess_confidence(score, threshold_type="standard"):
    """Assess AI confidence score."""
    thresholds = CONFIDENCE_THRESHOLDS
    
    for level, info in thresholds.items():
        if score >= info["min"]:
            return {
                "level": level,
                "action": info["action"],
                "score": score
            }

Calibration Assessment

def assess_calibration(predicted_probs, observed_outcomes, bins=10):
    """Assess if predicted probabilities match observed rates."""
    import numpy as np
    
    bin_edges = np.linspace(0, 1, bins + 1)
    calibration_errors = []
    
    for i in range(bins):
        bin_min = bin_edges[i]
        bin_max = bin_edges[i + 1]
        
        mask = (predicted_probs >= bin_min) & (predicted_probs < bin_max)
        if mask.sum() > 0:
            predicted = predicted_probs[mask].mean()
            observed = observed_outcomes[mask].mean()
            calibration_errors.append({
                "bin": f"{bin_min:.1f}-{bin_max:.1f}",
                "predicted": predicted,
                "observed": observed,
                "error": abs(predicted - observed)
            })
    
    return calibration_errors

Comparative Analysis

AI vs Radiologist

def compare_ai_radiologist(ai_findings, radiologist_findings):
    """Compare AI and radiologist findings."""
    agreement = {
        "total_ai_findings": len(ai_findings),
        "total_radiologist_findings": len(radiologist_findings),
        "agreed_findings": [],
        "ai_only": [],
        "radiologist_only": [],
        "disagreed_characteristics": []
    }
    
    ai_set = set([f["uid"] for f in ai_findings])
    rad_set = set([f["uid"] for f in radiologist_findings])
    
    agreement["agreed_findings"] = list(ai_set & rad_set)
    agreement["ai_only"] = list(ai_set - rad_set)
    agreement["radiologist_only"] = list(rad_set - ai_set)
    
    agreement["agreement_rate"] = len(agreement["agreed_findings"]) / len(ai_set | rad_set)
    
    return agreement

Concordance Metrics

def calculate_concordance(ai_results, radiologist_results):
    """Calculate AI-radiologist concordance."""
    comparison = compare_ai_radiologist(ai_results, radiologist_results)
    
    return {
        "sensitivity": (
            len(comparison["agreed_findings"]) / 
            len(comparison["radiologist_only"] | comparison["agreed_findings"])
        ),
        "ai_precision": (
            len(comparison["agreed_findings"]) / 
            len(comparison["ai_only"] | comparison["agreed_findings"])
        ),
        "agreement_rate": comparison["agreement_rate"]
    }

Error Pattern Analysis

Aggregate Review

def analyze_error_patterns(study_results, time_period="monthly"):
    """Analyze patterns in AI errors over time."""
    patterns = {
        "false_positives": [],
        "false_negatives": [],
        "by_modality": {},
        "by_finding_type": {},
        "by_anatomy": {}
    }
    
    for result in study_results:
        if result["outcome"] == "fp":
            patterns["false_positives"].append(categorize_error(result))
        elif result["outcome"] == "fn":
            patterns["false_negatives"].append(categorize_error(result))
        
        # Categorize by modality
        mod = result.get("modality", "unknown")
        patterns["by_modality"][mod] = patterns["by_modality"].get(mod, 0) + 1
    
    return patterns

Trend Analysis

def analyze_trends(error_data, date_range):
    """Analyze error trends over time."""
    import pandas as pd
    
    df = pd.DataFrame(error_data)
    df["date"] = pd.to_datetime(df["date"])
    
    return {
        "daily_avg_errors": df.groupby("date").size().mean(),
        "error_rate_trend": calculate_trend(df["date"], df["error_rate"]),
        "common_patterns": df["pattern"].value_counts().head(5)
    }

Quality Reporting

Generate QA Report

def generate_qa_report(ai_results, radiologist_results, date_range):
    """Generate comprehensive QA report."""
    metrics = calculate_detection_metrics(
        tp=len(agreed),
        fp=len(ai_only),
        fn=len(rad_only),
        tn=0
    )
    
    concordance = calculate_concordance(ai_results, radiologist_results)
    fp_analysis = analyze_false_positives(ai_results, radiologist_results)
    fn_analysis = analyze_false_negatives(ai_results, radiologist_results)
    
    return {
        "period": date_range,
        "total_studies": len(ai_results),
        "detection_metrics": metrics,
        "concordance": concordance,
        "false_positives": fp_analysis,
        "false_negatives": fn_analysis,
        "recommendations": generate_recommendations(metrics, concordance)
    }

Report Template

AI QUALITY ASSURANCE REPORT
==========================
Period: March 2026
Generated: 2026-04-03

SUMMARY
-------
Total Studies Reviewed: 500
AI Findings: 150
Radiologist Findings: 145
Agreement Rate: 92%

DETECTION METRICS
-----------------
Sensitivity: 94.5%
Specificity: 89.2%
PPV: 91.3%
NPV: 93.1%

ERROR ANALYSIS
--------------
False Positives: 12 (8%)
  - Vessels: 5
  - Artifacts: 4
  - Other: 3

False Negatives: 7 (5%)
  - Small nodules: 3
  - Atypical appearance: 2
  - Technical quality: 2

RECOMMENDATIONS
---------------
1. Adjust confidence threshold for lung nodules
2. Add motion correction preprocessing
3. Review vessel-mimic patterns

Quality Assurance Workflow

Review Process

QA_WORKFLOW = {
    "1_initial": {
        "ai_results": "All studies",
        "action": "Automatic collection"
    },
    "2_sampling": {
        "method": "Random sampling",
        "rate": "10% of normal, 100% of critical",
        "action": "Random selection"
    },
    "3_comparison": {
        "process": "AI vs final report",
        "action": "Flag discrepancies"
    },
    "4_review": {
        "reviewer": "QA radiologist",
        "action": "Adjudicate disagreements"
    },
    "5_feedback": {
        "loop": "AI model update",
        "action": "Continuous improvement"
    }
}

Related Skills

• ai-detection-pipeline: For AI system configuration
• radiology-metrics: For metric tracking
• radiology-report-analysis: For finding validation
• dataset-preprocessing: For test data preparation

Examples

Example 1: Review AI Finding

Is this AI-detected lung nodule a false positive?

review = review_ai_finding(
    ai_finding={"location": "RLL", "size": 8, "confidence": 0.75},
    priors={"prior_ct": "6mm stable nodule RLL"},
    imaging={"images": ["series1.dcm"]}
)

Example 2: Generate Monthly Report

Generate QA report for AI performance in March 2026

report = generate_qa_report(
    ai_results=monthly_ai_results,
    radiologist_results=monthly_rad_results,
    date_range={"start": "2026-03-01", "end": "2026-03-31"}
)

Example 3: Analyze Error Patterns

Identify error patterns in recent AI detections

patterns = analyze_error_patterns(
    study_results=last_30_days,
    time_period="monthly"
)