19  Enhanced Rescan Analysis

19.1 Introduction

Rescan analysis reveals critical quality metrics and hidden costs in the digital pathology workflow. Each rescan represents: - Quality Issues: Focus problems, tissue artifacts, or technical failures - Time Costs: Re-handling, re-loading, and additional scan time - Labor Costs: Technician intervention and quality review - Delay Impact: Extended turnaround time for affected cases

This enhanced analysis investigates rescan patterns across multiple dimensions: scanner performance, temporal trends, and operational factors.

19.2 Load Data and Run Analysis

19.3 Overall Statistics

Overall Rescan Statistics
Metric Value
Total Unique Slides 618,304
Slides Requiring Rescan 70,345
Overall Rescan Rate (%) 11.38%
First-Pass Success Rate (%) 88.62%
Single Rescans 66,022
Multiple Rescans (≥3 attempts) 4,323
Average Time to Rescan (hours) 46.1
Scanner Changed for Rescan (%) 5.4%

19.4 Rescan Distribution

Interpretation: - Green: Successful first-pass scans (target: >95%) - Orange: Required one rescan (acceptable with proper QC) - Red: Multiple failures (requires investigation)

19.5 Performance by Slide Category

Rescan Statistics by Slide Category
Category Total Slides Rescanned Rescan Rate (%) First Pass Success Avg Time to Rescan (hrs)
Ancillary 278474 37861 13.60 240613 56.06
Routine HE 339830 32484 9.56 307346 34.56

Key Finding: Are routine HE slides or ancillary stains more prone to rescans?

19.6 Scanner Performance Comparison

Scanner-Specific Rescan Rates
Scanner Total Slides Rescanned Rescan Rate (%) First-Pass Success (%) Avg Scans per Slide
SISLI_TECHNOMIND 5 5 100.00 0.00 2.00
SISLI_AT2_3 2345 1872 79.83 20.17 1.82
SPIS_HM1 197 142 72.08 27.92 2.03
SISLI_DEMO 9 4 44.44 55.56 1.78
BAH_ARG 26 11 42.31 57.69 1.81
BAH_ARG2 73 30 41.10 58.90 1.62
SISLI_ARG 27 10 37.04 62.96 1.81
SISLI_HMMS 703 165 23.47 76.53 1.61
SISLI_AT2_2 79409 14175 17.85 82.15 1.20
SISLI_MAG 353 62 17.56 82.44 1.49
SISLI 779 104 13.35 86.65 1.53
SISLI_AT2 115690 14515 12.55 87.45 1.15
SISLI_MOTIC 196 24 12.24 87.76 1.19
SISLI_GT450 213858 21103 9.87 90.13 1.11
SISLI_GT450_2 190842 17534 9.19 90.81 1.10
SECTRA-PATO 10213 511 5.00 95.00 1.07
ANTALYA 227 11 4.85 95.15 1.06
SISLI_GT450_3 2541 59 2.32 97.68 1.02
SISLI_CS2 810 8 0.99 99.01 1.01
YSF1 1 0 0.00 100.00 1.00

Clinical Implications: - Scanners with high rescan rates may need calibration or maintenance - Consistent underperformers should be investigated for hardware issues - Best performers can inform optimal scanning protocols

19.7 Temporal Patterns

19.7.1 Day of Week Analysis

Questions to Ask: - Does Monday have higher rescan rates (weekend slide storage issues)? - Does Friday show lower quality (end-of-week fatigue)? - Are staffing levels consistent across days?

19.7.2 Hour of Day Analysis

Operational Insights: - Night shift vs day shift quality differences - Fatigue effects during long shifts - Impact of lighting conditions on slide preparation

19.7.3 Monthly Trend

Strategic Questions: - Is quality improving over time (declining rescan rate)? - Do seasonal factors affect performance? - Did process changes impact rescan rates?

19.8 Cost Analysis

Estimated Cost Impact of Rescans
Metric Value
Cases Affected by Rescans 20,536
Total Rescan Events 70,345
Estimated Labor Cost (hours) 5862.1 hrs (146.6 FTE weeks)
Estimated Delay Impact (hours) 140690.0 hrs (5862.1 days)

Assumptions: - 5 minutes average handling time per rescan (unloading, reloading, QC) - 2 hours average delay per rescanned slide (queue re-entry, priority handling)

Hidden Costs: - Pathologist waiting time - Technician interruption costs - Extended patient anxiety - Delayed treatment initiation

19.9 Root Cause Hypotheses

Based on the data, potential root causes for rescans include:

  1. Technical Issues
    • Focus calibration problems
    • Barcode reading failures
    • Mechanical loading errors
  2. Slide Quality
    • Inadequate tissue adhesion
    • Coverslip bubbles or debris
    • Staining artifacts (too light/dark)
  3. Operational Factors
    • Rushed loading during peak hours
    • Inadequate technician training
    • Inconsistent quality standards
  4. Environmental
    • Temperature/humidity variations
    • Dust or contamination
    • Equipment aging

19.10 Recommendations

19.10.1 Immediate Actions (High Priority)

  1. Investigate High-Rescan Scanners: Focus on scanners exceeding overall average
  2. Quality Control Review: Implement pre-scan inspection checklist
  3. Training Assessment: Review technician protocols, especially during problem shifts
  4. Preventive Maintenance: Schedule calibration for underperforming equipment

19.10.2 Short-Term Improvements

  1. Real-Time Monitoring: Dashboard showing rescan rates by shift and scanner

19.11 Causes of Rescans

We categorize reasons for rescans (e.g., “focus”, “tissue_detection”, “other”).

Common Industry Failure Modes: - ROI Detection Failures: ~64% - Tissue Skipping: ~23% - Barcode/Label Issues: ~0.5% (can be 20% in early implementations)

Understanding our specific failure modes allows for targeted interventions.

  1. Root Cause Tracking: Categorize rescan reasons (focus, loading, staining, etc.)
  2. Feedback Loop: Share performance metrics with lab staff
  3. Process Standardization: Document best practices from top performers

19.11.1 Long-Term Strategy

  1. Trend Analysis: Monthly review of rescan rates to track improvement
  2. Predictive QC: Use AI to flag slides likely to fail before scanning
  3. Equipment Investment: Consider replacing chronic underperformers
  4. Cost-Benefit Analysis: Evaluate impact of quality improvements on overall TAT

19.12 Requested Rescans (Pathologist Feedback)

We also analyze specific rescan requests filed by pathologists (“Geri Bildirim”). These represent cases where the initial scan was insufficient for diagnosis.

<table class="table table-striped table-hover" style="margin-left: auto; margin-right: auto;">
<caption>Top 10 Pathologists Requesting Rescans</caption>
 <thead>
  <tr>
   <th style="text-align:left;"> requesting_pathologist </th>
   <th style="text-align:right;"> n </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;"> Türkan Atasever Rezanko </td>
   <td style="text-align:right;"> 68 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Şemsi Yıldız </td>
   <td style="text-align:right;"> 49 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Murat Oktay </td>
   <td style="text-align:right;"> 47 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Doç. Dr. Serdar Balcı </td>
   <td style="text-align:right;"> 43 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Gülen Bülbül Doğusoy </td>
   <td style="text-align:right;"> 35 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Prof. Dr. Türkan Atasever Rezanko </td>
   <td style="text-align:right;"> 35 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Uzm. Dr. Fadime Gül Salman </td>
   <td style="text-align:right;"> 31 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Uzm. Dr. Emre Karakök </td>
   <td style="text-align:right;"> 29 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Prof. Dr. Gülen Bülbül Doğusoy </td>
   <td style="text-align:right;"> 25 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> Prof.dr. Fatma Aktepe </td>
   <td style="text-align:right;"> 25 </td>
  </tr>
</tbody>
</table><table class="table table-striped table-hover" style="margin-left: auto; margin-right: auto;">
<caption>Top 10 Reasons for Rescan Requests</caption>
 <thead>
  <tr>
   <th style="text-align:left;"> description </th>
   <th style="text-align:right;"> n </th>
  </tr>
 </thead>
<tbody>
  <tr>
   <td style="text-align:left;"> net olmamış </td>
   <td style="text-align:right;"> 7 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> sb </td>
   <td style="text-align:right;"> 7 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> bulanık </td>
   <td style="text-align:right;"> 4 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> giemsa taranmamış </td>
   <td style="text-align:right;"> 4 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> kullanılamaz görüntü olmuş. tekrar tarar mısınız </td>
   <td style="text-align:right;"> 4 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> net olmamiş </td>
   <td style="text-align:right;"> 4 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> ss </td>
   <td style="text-align:right;"> 4 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> dr nural </td>
   <td style="text-align:right;"> 3 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> net değil, tekrar taransın </td>
   <td style="text-align:right;"> 3 </td>
  </tr>
  <tr>
   <td style="text-align:left;"> bulanik </td>
   <td style="text-align:right;"> 2 </td>
  </tr>
</tbody>
</table>

19.13 Benchmarking

Industry standards for digital pathology rescan rates (Asta Report 2025): - Excellent: <1.5% rescan rate - Acceptable: 1.5-3.0% rescan rate - Needs Improvement: 3.0-5.0% rescan rate - Critical: >5.0% rescan rate

Current Performance:

Your rescan rate: 11.38% - Critical ✗

19.14 Conclusion

Rescan analysis reveals both quality metrics and operational efficiency. By systematically tracking and reducing rescans, laboratories can: - Improve turnaround times - Reduce operational costs - Enhance diagnostic confidence - Optimize resource utilization

The goal is continuous improvement toward <2% rescan rate while maintaining diagnostic quality.