[Magnetic resonance imaging of brain tumors]

Magnetic resonance imaging (MRI) has been applied to the diagnosis of brain tumors very widely and MRI is now replacing computed tomography (CT). One of the most important advantages of MRI is influence of multiple tissue and machine parameters on the signal intensities. In addition, capability of imaging in various planes and multislices is another advantage for the brain tumor diagnosis. The coronal image is important when the abnormal side can be compared with the normal side and midline lesions can be easily diagnosed with sagittal imaging. Transverse imaging is important when comparison is made with CT. Many brain tumors show increased signal intensity on T2-weighted images and decreased signal intensity on T1-weighted images and decreased signal intensity on T1-weighted images. The difference of signal intensity in various brain tumors including glioma, meningioma and other important tumors are discussed. MRI is superior to CT in many brain tumors, but poor delineation of calcification and hemorrhage is a disadvantage of MRI.