BPT-View

A lightweight Python viewer for .BPT tomography files, with support for:

• axial, coronal, and sagittal MPR
• frontal MIP
• curved panoramic reconstruction (curved MPR)
• brightness/contrast adjustment
• visual Z aspect adjustment
• movable panel dividers
• export of rendered slices

Features

• Structured .BPT parser
• Async volume loading with responsive UI
• Axial / Coronal / Sagittal views
• Frontal MIP view
• Curved panoramic reconstruction from user-defined spline
• Crosshair toggle
• Per-slice export (axial, coronal, sagittal)
• Window/level controls
• Resizable split panes

Requirements

Install dependencies with:

pip install numpy imagecodecs Pillow scipy

Or from requirements.txt:

pip install -r requirements.txt

Usage

Run without arguments to choose a file manually:

python bpt_viewer.py

Run with a .BPT file path:

python bpt_viewer.py path/to/exam.bpt

About the .BPT format

This project includes a parser for the .BPT container layout observed during development.

Observed structure:

• 64-byte header (16 × uint32, little-endian)

• first JPEG slice stored without a size prefix

• remaining slices stored as:

  • [uint32 little-endian size]
  • [JPEG payload]

• optional undocumented trailing bytes after the last slice

Mapped header fields:

Index	Field	Type
h[6]	width	uint32
h[7]	height	uint32
h[8]	num_slices	uint32
h[9]	spacing_x	float32 LE
h[10]	spacing_y	float32 LE
h[11]	spacing_z	float32 LE
h[15]	first slice length	uint32

Technical notes

Display geometry

Rendering and click mapping use the same geometry function, which keeps interaction consistent across panels.

MIP consistency

The frontal MIP follows the same internal display convention used by coronal and sagittal views, keeping crosshair and click mapping aligned.

Curved panoramic reconstruction

The panoramic view is reconstructed from a spline drawn in the axial view and sampled in physical space, using interpolated slab MIP along the curve.

Z aspect

The viewer exposes a visual Z aspect control for display. The default display preset is 1.5×, while the physical aspect ratio derived from spacing is still tracked internally.

Known limitations

• The implementation is based on the .BPT structure observed in this project. Other .BPT variants may not work.
• Panoramic reconstruction runs on the UI thread and may briefly pause the interface on larger volumes.
• The panoramic window does not auto-update when window/level changes; it must be recalculated.
• No distance measurement tools are included.
• No keyboard shortcuts are currently implemented.

Disclaimer

This project is a personal/technical viewer for .BPT tomography files.

It is:

• not a certified medical workstation
• not intended for official clinical diagnosis
• not a replacement for approved medical imaging software

License

MIT

Portuguese version

For a Portuguese version of this documentation, see:

README.pt-BR.md