To evaluate the value of length and offset varied saturation (LOVARS)¹ in the diagnosis of gliomas, and compared with amide proton transfer (APT).A total number of 16 patients (5 females and 11 males; mean age, 51±12y) with 12 high-grade and 4 low-grade gliomas confirmed pathologically were recruited in this study. All MR imaging was performed on a 3.0 T MR scanner (MAGNETOM Trio, Siemens AG, Erlangen, Germany) with a 12-channel head coil. Axial and sagittal T1-weighted and T2-weighted images were acquired for morphological analysis. APT and LOVARS imaging were performed using a prototype 3D GRE CEST sequence with TR/TE of 1620/2.87 ms, FA of 12, slice thickness of 5 mm, FOV of 256´256 mm2, and matrix of 128´128. For APT imaging, 4 saturation RF pulses with the power of 3.0 mT were given at 21 frequency offsets between ±5 ppm. The magnetization transfer asymmetry at ±3.5 ppm was used for calculation of ATP images. For LOVARS imaging, 2 and 5 saturation RF pulses with the power of 2.0 mT were given at ±3.5 ppm for 3 cycles. The LOVARS phase images were calculated by the FFT of the oscillation signals. ROIs were placed in the area of solid tumor component with avoid of the areas of hemorrhage, necrosis, cystic component, edema and calcification to measure the singles intensity in APT . According to the feature of the gliomas in conventional MRI, the characteristic in LOVARS phase images was described and compared with APT images.Figure 1 showed the example cases of conventional MRI, APT and LOVARS phase images in a low-grade and a high-grade glioma. In the the low-grade glioma, APT did not show significant differences between tumor area and background tissues (P >0.05), but showed high single intensity in the tumor area in high-grade glioma (P <0.001). The signal intensity in high-grade glioma is higher than in low-grade glioma in APT images (P <0.01). In LOVARS phase images, both low-grade and high-grade showed higher signals in tumor area than the background tissues (P <0.05), and there was no significant difference between the signal intensities in low-grade and high-grade tumors. However, in LOVARS phase images, the inhomogeneity signals in the areas of hemorrhage, necrosis, and edema was helpful to further evaluate the glioma.In this study, we compared APT and LOVARS in the diagnosis of glioma. Quantitative analysis showed that the value in tumor areas is significant different between low and high grade glioma in APT images, but has no difference in LOVARS phase images. These results indicated that APT image has more value in distinguishing low and high grade glioma. LOVARS phase images showed significant higher signal in gliomas than peripheral tissue, and also the heterogeneous internal components of the glioma was showed as inhomogeneous signals, which represented the different pathological areas, such as hemorrhage, necrosis, cystic component, edema and calcification. Thus, by combining APT and LOVARS MR imaging together, the diagnosis accuracy of glioma would be increased.APT images is useful in distinguishing low-grade and high-grade glioma, while LOVARS phase images shows better contrast between glioma and peripheral tissue, and the internal heterogeneous components of the glioma.