Rapid 3D-T(1) mapping of cartilage with variable flip angle and parallel imaging at 3.0T.
OBJECTIVE
To rapidly acquire T(1)-weighted images using a three-dimensional fast low angle shot (3D FLASH) sequence in combination with generalized autocalibrating partially parallel acquisitions (GRAPPA) and variable flip angle (VFA) method at 3.0T.


METHODS
3D T(1) maps of model systems (gadolinium [Gd] and agarose phantoms), bovine cartilage, and human subjects were constructed on a 3.0T clinical whole-body MR scanner. The T(1) values of model systems measured using the 2D inversion-recovery fast-spin-echo (IR-FSE) sequence were considered as a reference method to validate the rapid 3D method for comparison.


RESULTS
The root mean square coefficient of variation percentage (RMS-CV%) of the median T(1) of agarose phantom across different acquisition methods was approximately 6.2%. The RMS-CV% of the median T(1) of bovine cartilage across different acquisition methods was approximately 4.1%. The RMS-CV% of median T(1) of the cartilages among the subjects was between approximately 7.3% to 11.1%. In our study, rapid 3D-T(1) mapping with VFA and parallel imaging with different acceleration factors (AFs) (AF = 1, 2, 3, and 4) seems to have no obvious influence on the T(1) mapping (before and after contrast agent administration).


CONCLUSIONS
The preliminary results demonstrate that it is possible to quantify 3D-T(1) mapping of the whole knee joint (with 0.7 mm(3) isotropic resolution) under approximately five minutes with excellent in vivo reproducibility at 3.0T.
Wang
Ligong
L
Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York 10016, USA. wongl01@med.nyu.edu
Schweitzer
Mark E
ME
Padua
Abraham
A
Regatte
Ravinder R
RR
D000465:Algorithms; D000818:Animals; D002138:Calibration; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D002417:Cattle; D003287:Contrast Media; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000033:anatomy & histology*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012685:Sepharose
D003287:Contrast Media; D012685:Sepharose