Three-Dimensional Gradient-Echo–Based Amide Proton Transfer-Weighted Imaging of Brain Tumors: Comparison With Two-Dimensional Spin-Echo–Based Amide Proton Transfer-Weighted Imaging

<jats:sec> <jats:title>Objective</jats:title> <jats:p>Although amide proton transfer–weighted (APTw) imaging is reported by 2-dimensional (2D) spin-echo–based sequencing, 3-dimensional (3D) APTw imaging can be obtained by gradient-echo–based sequencing. The purpose of this study was to compare the efficacy of APTw imaging between 2D and 3D imaging in patients with various brain tumors.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>A total of 49 patients who had undergone 53 examinations [5 low-grade gliomas (LGG), 16 high-grade gliomas (HGG), 6 malignant lymphomas, 4 metastases, and 22 meningiomas] underwent APTw imaging using 2D and 3D sequences. The magnetization transfer ratio asymmetry (MTR<jats:sub>asym</jats:sub>) was assessed by means of region of interest measurements. Pearson correlation was performed to determine the relationship between MTR<jats:sub>asym</jats:sub> for the 2 methods, and Student's <jats:italic toggle="yes">t</jats:italic> test to compare MTR<jats:sub>asym</jats:sub> for LGG and HGG. The diagnostic accuracy to differentiate HGG from LGG of the 2 methods was compared by means of the McNemar test.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Three-dimensional APTw imaging showed a significant correlation with 2D APTw imaging (<jats:italic toggle="yes">r</jats:italic> = 0.79, <jats:italic toggle="yes">P</jats:italic> < 0.0001). The limits of agreement between the 2 methods were −0.021 ± 1.42%. The MTR<jats:sub>asym</jats:sub> of HGG (2D: 1.97 ± 0.96, 3D: 2.11 ± 0.95) was significantly higher than those of LGG (2D: 0.46 ± 0.89%, <jats:italic toggle="yes">P</jats:italic> < 0.01; 3D: 0.15 ± 1.09%, <jats:italic toggle="yes">P</jats:italic> < 0.001). The diagnostic performance of the 2 methods to differentiate HGG from LGG was not significantly different (<jats:italic toggle="yes">P</jats:italic> = 1).</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The potential capability of 3D APTw imaging is equal to or greater than that of 2D APTw imaging and is considered at least as valuable in patients with brain tumors.</jats:p> </jats:sec>