NIFTI  Float32 subtype:  enabled the loading.

AutoFocus registration with the initial transform: restored to working condition.

Fixed the polynomial transform reslicing problem.

VTF file format read: Added the diagnostic to identify if user tries to load the old VTF format which is no longer supported and displays the suggestion to the user.

Disabled Huffman compression of large REAL volumes with MaxVoxVal>1M, so for major
speed up in saving and loading.

Incorporated support for ANALYZE 32-bit float files.

BiCal non-uniformity correction Dialog is further simplified and optimized:

Numerous improvement to BiCal algorithm:
1. parallelization with about 20% further speed up
2. Another 20% NU improvement on BPD dataset

BiCal Non-uniformity correction:  resolved an issue when simply applying Bias Field correction to the Air voxels would amplify the noise.  New algorithm intelligently corrects transition from Air to tissue so the effective field remains smooth. The non-unifomity correction improvement in the tissue is identical for both variants.

Simple Field application makes the noise amplified.

Intelligent processing of Tissue-to-Air transition

Restore core functionality inside the ROI Wave distance functions based on voxel morphology.

case RE:  difference between "Image matrix center alignment" and "Dicom-tag based alignment"

DICOM tag-based alignment. Complete mismatch of DICOM tags

Image center based alignment, close enough.

Suitable parameters for PET4D-MR4D registration "WITHOUT DICOM alignment"

case RE:   PET4D-MR4D registration

Coronal artery AIF at 1.2 sec time resolution

Dialog RoiStat4D:  when concentration method change the Curve panel should immediately redraw now to reflect new settings.

Kidney AIF experiment: segmentation and concentration from NUFFT.

AIF ROI was automatically sampled using IDIF (~4000 voxels)

Corresponding signal for the AIF

Basic linear Concentration (S/S0-1)  (Conc max = 9.94)

FTWE concentration with actual T1\TR\Flip Angle values  (Conc max=3.50)

Further optimized and streamlined BiCal dialog User interface.  This is the final form for ISMRM.

BiCal: changed the order of  resolution change and NU field application to reduce the blurring of the resulting volume.

a) New result                                             b) Old result

BiCal: fixed numerous memory leaks.

Various concentration models were compared for the GRASP and NUFFT carotid artery curves.

Both curves were provided as *.txt file in FireVoxel TAC format.  Upon opening FireVoxel (no document present) user choose  "MainMenu>Applications>Convert TAC to Concentration"

After choosing the file name, the ViewTac dialog appears with the original GRASP curve

General Concentration conversion dialog box will appear.  User selects the FTWE concentration model.
The core model is:  S = M0*sin(alpha)* ((1-exp(-TR/T1(c )) / (1-cos(alpha)*exp(-TR/T1(c ))

Optionally (with T2* checkbox) the T2* effect could be accounted for, with the following formula

S = M0*sin(alpha)* ((1-exp(-TR/T1(c )) / (1-cos(alpha)*exp(-TR/T1( c)))*exp(-TE/T2*(c))

We start with loading the Carotid AIF file obtained from GRASP:

original Curve from GRASP

After applying the basic FTWE model we obtain this curve

GRASP FTWE (Max Concentration 0.2944)

 Next we enable the FTWE with the T2* effect

GRASP  FTWE with T2* effect (Max concentration 17.94)

In the next part of the experiment we load with the NUFFT curve.  This AIF was obtained automatically with FireVoxel-IDIF function and the ROI size was about 2000 voxels.

NUFFT original curve

After applying the basic FTWE model we obtain this concentration curve

FTWE model, max Concentration = 1.71

  Next we enable the FTWE with the T2* effect:

FTWE model with T2* effect, max concentration = 19.9




CONCLUSION:
NUFFT with FTWE model seem to provide best result with more realistic concentration values. But further evaluations are required.