New release to describe a number of improvements to the package.
Modeling
feng_1tc_tac()is a model for fitting any old TAC. It is used for fitting the reference region with SiMBA reference tissue models, and can also be very helpful when combined with SRTM2 for modelling [11C]UCB-J to smooth out noisy CS TACs.- Added a
twotcm_irr()function for fitting the irreversible 2TC model, i.e. 2TC3k. - Added a
twotcm_macro()function for an alternative parameterisation of the 2TC focusing on macroparameters, where one has control over limits for K1, Vnd, BPp and k4, and can set Vnd, BPp or k4 to a predetermined value. - Fixed the issue with vB being considered as a fitted parameter when defined, which was causing incorrect AIC values. Thanks so much to Ronald Boellaard for bringing this to my attention!
Blood
- Whole blood data is now inferred for time points with plasma and no blood to accommodate datasets from research groups who collect mostly plasma measurements.
Plotting
- Fixed an issue with delay fitting when the TAC was also moved
- Added the ability to plot only one of the lines when plotting blooddata objects using the select_line input, which takes the same values as
bd_addfit()modeltype argument, i.e. BPR, Blood, AIF, parentFraction - BPR data is now inverted to PBR if it is too high and leaves the frame of the plot.
BIDS
- Added support for importing bloodstream outputs so that one can very simply load in the generated input objects from a whole study using
bloodstream_import_inputfunctions(), or AIF parameters usingbloodstream_import_aifpars() - Updated the BIDS parser
Changes to functionality
- The AIF models now automatically use a weighting function when fitted. This improves performance generally, but may cause slightly different fits. The old weights function can be selected using weightscheme=1.