Architosh Staff ([email protected])

4 Sep 2001

Mac3D: Second reader Q: More help on Medical 3D on Mac

Architosh received yet another request on assistance for medical 3D imaging on the Macintosh platform, an area we profess to have very little knowledge of. In our first story a fellow Mac user wrote in with a suggestion on an application. We thank such readers for helping other Mac users stay on the platform. Hopefully someone can help Dr. Lars Frich, MD who recently wrote in:

Hi,

I saw you recently used your experience in 3D to help a doctor who uses Mac for scientific work (Mac3D Science Q: Mac medical scientist needs your 3D help!). I hope you will pardon me for addressing you directly, but I have a similar, if less complex problem. The following was posted in the Community today. Hopefully this is an easy one for you..

Lars Frich, MD

Surgical department

Norwegian National Hospital

Rikshospitalet

0027 Oslo, NORWAY

Dr Lars Frich's Request

I have no experience in the world of 3D modeling.

As an ongoing medical research project I would like to be able to calculate an area based on a circumference.

Some more details: Having made a lesion in tissue we would like to slice the tissue in slices with predefined thickness, take a photo of the surface of each the slices and trace the circumference of the lesion / the border between normal and abnormal tissue. We would further like to be able to calculate the area within the part of the slice that is abnormal. Afterwards we would like to be able to build a 3D model of the abnormal tissue based on the area of the separate slices.

A simpler version of the same problem - how do you calculate the area of the yellow part of a sliced boiled egg, given that you know the scale of the image that you process? And how do you build a 3D model of the yellow part of the boiled egg from the slices of the egg and calculate the volume?

If possible, please consider that we would not like to buy a full (expensive) software package to make these quite simple operations if a simpler software package will do the job.

This problem sounds completely within the capabilities of a solids modeling program used for industrial design purposes, wherein area and volumes of negative cavities (or what's left over subtractions, etc.) are often determined for various purposes.

Since we assume the lesions and tissue areas are not of simple geometric form a program would need to be able to trace and form shapes with bezier curves. The control points of which might greatly assist the doctors in controlling the precise shape of the abnormal tissue. The problem sounds pretty exciting when you think about it.

We think FormZ from Autodessys Inc., or Cobalt from Ashlar Inc, with its advanced associative Class-A NURBS surface modeling may do the trick. And again solidThinking by GESTEL, Maya by Alias/Wavefront and others maybe work as well. One last app that may be suitable is Neoform by Formation Design Systems.

To see other Mac 3D apps visit our comprehensive Digital Practice Guide.