C# And Anonymous Types - Iterate Through A DataTable While Manually Building An Anonymous Type

I am currently implementing a client-side paging solution using ASP.NET, jQuery and JSON.

I have been following the excellent article from encosia: http://encosia.com/2008/08/20/easily-build-powerful-client-side-ajax-paging-using-jquery/

In my Web Method I retrieve my data from the database as a DataTable:

DataTable categoryProducts = ProductViewerAccess.GetCategoryProducts
("AA", 4, 0, Page.ToString(), out howManyPages, "FALSE", 0, "CostPrice", "asc", destinationList);

I then retrieve the data from the DataTable into an anonymous type:

var feeds =
from feed in categoryProducts.AsEnumerable()[code]....

This all works great.

However, I would like to extend the code to perform some evaluation checks (e.g., check that various columns in the DataTable are not NULL) and other pre-processing (e.g., call various functions to build the image URL based on the image ID - which is another column in the DataTable not shown in the code fragment) before I return the resulting rows of the DataTable as an anonymous type to the client-side.Basically, I want to iterate through the DataTable, perform the evaluation checks and pre-processing, while building my anonymous type manually as I go. Or maybe there is a better way to achieve this?