[Clinical factors in glioblastoma and neuroradiology]

Glioblastoma is found preferentially in men (1.5/1), nearing age 60, but all ages can be concerned. Clinical symptoms are intracranial mass without specificity, intracranial hypertension and localization signs. From the clinical history, the essential prognosis factors are: age, Karnofsky score and cognitive dysfunction. Conventional MRI sequences, including T1-FSE with and without contrast injection and T2-FSE or Flair-weighted sequences, provide the diagnosis in most cases, showing an intraparenchymal mass with a heterogeneous, irregularly enhanced signal. Other sequences define the tumor more precisely. Diffusion sequences provide the differential diagnosis with an abscess or a highly cellular tumor such as lymphoma. Perfusion sequences allow appreciation of tumor microvascularization outlining the tumor's most active areas. Magnetic resonance spectroscopy (SRM) sequences allow noninvasive exploration of tumor metabolism. Beyond its diagnostic role, imagery assists the surgical procedure itself, particularly with functional MRI, allowing a precise preoperative mapping of functional cortical areas. Biopsy can also be guided toward the most active areas of the tumor. In the postoperative period, MRI completes the surgeon's impression on whether or not there is residual tumor. Finally, this exam has become essential in follow-up to diagnose recurrence, radionecrosis, or pseudoprogression.