•With MRI: tissue structure and anatomical topographic localization of a tumor in three dimensions define the tumor precisely and allow stereotactic biopsy

•The long duration of the procedure is a disadvantage

•MR spectroscopy can be useful in differentiating between high-grade and low-grade tumors

9.7.2 Positron Emission Tomography (PET)

• PET scanning provides detection of metabolites and metabolic alterations within the tissue, thus can be helpful in distinguishing tumors from non-neoplastic lesions

9.7.3 Conventional Radiography of the Skull

• Conventional radiography shows the bony structure of the skull, separating off sutures due to high intracranial pressure in small children and calcification within the brain

9.7.4 Special Methods for Special Indications

9.7.4.1 Bone Scintigraphy

• Used where tumors are close to bone structures, e.g., cerebral hemisphere tumors

9.7.4.2 Angiography

• Angiography provides vascular supply and degree of vascularization of the tumor, including MR-angiography

9.7.4.3 Ultrasonography (in Infancy)

• Can demonstrate the displacement of the midline structure of the brain by tumors

9.7.4.4 Myelography

•In tumors of the spinal canal

•Determination of focal widening, erosion of the spinal canal and of intervertebral foramen, and of changes within the cerebral fluid

9.8Additional Diagnostic Tools

9.8.1Cerebral Fluid Analysis

•Chemistry and cytology of the cerebral fluid are used to determine spread of the tumor; findings may be important in subsequent treatment approaches