Instructions

About This Tool

TrackPKD is designed to help visualize the change in kidney and liver volumes over time for Autosomal Dominant Polycystic Kidney Disease (ADPKD). The tool calculates kidney growth rates, provides Mayo classification, and generates visualizations of volume changes.

Getting Started

1. Demographics Information: Enter anonymized ID (default: Subject 1) and subject height in the unit of choice (cm, m or ft/in). These values are used for calculating height-adjusted total kidney volume (htTKV).

2. Organ Volume Timepoints: Click "Add Timepoint" to add a new imaging scan. For each timepoint, you'll need to enter:

   • Age at scan (in years)
   • Right kidney volume (in mL)
   • Left kidney volume (in mL)
   • Liver volume (in mL, optional)

   Ideally, organ volumes of all timepoints should be calculated using the same measurement method, preferably deep learning based organ segmentation of abdominal MRI or CT.

3. Treatments and Interventions (Optional): Mark any treatments or interventions the patient received on the trajectory plots.

   • Band: marks a duration of time
   • Line: marks an event

4. Generate Results: After entering your data, click the "Update" button to calculate growth rates, Mayo classification, and generate visualizations.

Understanding Your Results

Once you click "Update", the tool generates comprehensive analysis outputs:

Summary Table

The summary table displays key metrics for each scan:

• Scan Number: Sequential numbering by age (e.g., 1, 2, 3). An asterisk (*) indicates the timepoint is excluded from growth rate calculation.
• Age: Patient age at scan
• Total Kidney Volume (TKV): Sum of left and right kidney volumes
• htTKV: Height-adjusted TKV
• Total Liver Volume (TLV): Liver volume (if entered)
• Mayo Class: Imaging classification
  • Class 1A: Slowest progression (<1.5% per year)
  • Class 1B: Slow progression (1.5-3% per year)
  • Class 1C: Moderate progression (3-4.5% per year)
  • Class 1D: Moderate-rapid progression (4.5-6% per year)
  • Class 1E: Rapid progression (>6% per year)

Plots

The tool generates interactive plots showing:

• Total kidney volume over time with regression line
• Liver volume over time (if data available)
• Mayo classification boundaries and patient trajectory

Plots can be viewed in linear scale and semi-log scale. Hover over data points to see detailed values.

Annual Kidney Growth Rate

By default, all timepoints are included in the growth rate calculation. However, you can exclude specific timepoints by unchecking the checkbox next to that timepoint.

The growth rate is calculated using linear regression assuming kidney volume increases with age in an exponential manner. This provides an annualized growth rate percentage.

Important Notes

• This tool is for research and educational purposes only
• Not intended for clinical decision-making
• All data is stored locally in your browser
• At least 2 timepoints are required to calculate growth rates
• Volume measurements should be from standardized imaging protocols

References

Hu, Z., Sharbatdaran, A., He, X. et al. Improved predictions of total kidney volume growth rate in ADPKD using two-parameter least squares fitting. Sci Rep 14, 13794 (2024). https://doi.org/10.1038/s41598-024-62776-8

Irazabal MV, et al. Imaging classification of autosomal dominant polycystic kidney disease: a simple model for selecting patients for clinical trials. J Am Soc Nephrol. 2015. https://doi.org/10.1681/asn.2013101138

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