Differences in low- and high-grade astrocytomas among various diagnostic MRI sequences that are currently utilized in astrocytoma diagnoses
| Imaging modality | Low-grade astrocytomas | High-grade astrocytomas |
|---|---|---|
| MRI | Well-defined homogeneous masses with little or no mass effect, vasogenic edema, or enhancement after contrast administration | Strong contrast enhancement, peritumoral edema (evident on T2-FLAIR sequences), mass effects, heterogeneity, central necrosis, and intratumoral hemorrhage on conventional MRI |
| SWI | Low ITSS grade | High ITSS grade |
| DWI | High ADC | Low ADC |
| PWI | Low rCBV | High rCBV |
| DCE | High Ktrans | Low Ktrans |
| MRS | Low Lip-Lac/Cr, low Cho/Cr | High Lip-Lac/Cr, high Cho/Cr |
SWI: susceptibility-weighted imaging; ITSS: intratumoral susceptibility score; DWI: diffusion-weighted imaging; ADC: apparent diffusion coefficient; PWI: perfusion-weighted imaging; rCBV: relative cerebral blood volume; DCE: dynamic contrast enhancement; Ktrans: volume transfer coefficient; MRS: magnetic resonance spectroscopy; Lip-Lac/Cr: lipid-lactate to creatine; Cho/Cr: choline to creatine