**7.1 MRI**

*Current Cancer Treatment*

• mixed germ cell tumor

• craniopharyngioma

**Metastatic tumors**

**5. Clinical manifestations**

**6. Radiological diagnosis**

**7. Computed tomography (CT)**

• pituicytoma

**Tumors of the sellar region**

• granular cell tumor of the neurohypophysis

• spindle cell oncocytoma of the adenohypophysis

Modified from the WHO Classification of Tumors of the CNS, 2007 [7].

The most common presenting symptoms of pediatric brain tumours are due to increased intracranial pressure. Headache and vomiting are two well-known symptoms associated with elevated intracranial pressure. Other signs, which reflect the increase in intracranial pressure, include drowsiness, confusion, nausea, sixth nerve palsy, papilledema, generalized seizures, and cognitive impairment. Focal signs and symptoms reflect the effect of the tumor on specific structures [8].

The features that play an important role in establishing the diagnosis are the age of the patient, location of the tumor and the imaging characteristics. Supratentorial tumors are more common in neonates and infants up to 2 years old, whereas infratentorial tumors are more common in children older than 2 years. Although some tumors may be found both supra- and infratentorially. Tumors that are considered mostly supratentorial and intraaxial include astrocytomas, such as diffuse astrocytoma, anaplastic astrocytoma, pleomorphic xanthoastrocytoma (PXA), subependymal giant cell astrocytoma (SEGA), and glioblastoma multi-forme (GBM); oligodendrocytoma; primitive neuroectodermal tumor (PNET); dysembryo-plastic neuroepithelial tumor (DNET); ganglioglioma; and desmoplastic infantile ganglioglioma. Some supratentorial extraaxial masses include arachnoid cysts, pineal region masses, and choroid plexus tumors. Imaging is an important aspect in the management of patients with brain tumors.

Imaging workup is largely based upon CT and MRI of the lesion. The technical development of CT and MRI methods has greatly enhanced brain tumor detection and sophisticated neuroimaging offers extra data by determining the metabolism and physiology of these lesions, which helps to diagnose and monitor brain neoplasms [9].

CT scan plays an important role in establishing diagnosis of brain tumours. It can detect both blood and calcification. But some tumors, particularly tumors of

• teratoma

**152**

It is the standard of care in children for imaging of suspected brain tumours.

The most useful imaging studies are T1-weighted sagittal images, gadolinium (Gd)-enhanced and unenhanced T1 axial images, T2-weighted axial images, and fluid-attenuated inversion recovery (FLAIR) sequences.

T1 images usually are better at demonstrating anatomy and areas of contrast enhancement. T2 and FLAIR images are more sensitive for detecting edema and infiltrative tumor.
