This atlas focuses on the imaging and treatment options available for giant intracranial aneurysms since 1990s in the beginning of the so-called modern endovascular era. During this period, there were significant advances made in the therapy of small intracranial aneurysms though the treatment of giant aneurysms continued to pose an insurmountable challenge. At the turn of this century, this grim scenario gradually improved with better understanding of the pathophysiology of giant intracranial aneurysms. This changed scenario in giant intracranial aneurysm therapy has been illustrated with the aid of informative clinical case studies. The clinical presentation of giant aneurysms in adults and children is described as are the merits of different imaging modalities explained and illustrated. Extensive consideration has been given to modern fusion imaging that has improved our insight into the nature of the disease. Endovascular treatment approaches (including illustrative open surgical approaches) and reconstructive and deconstructive strategies are fully documented, with careful attention given to factors that influence management strategies, treatment choice and complications.The atlas will be a valuable reference and practical aid for neuroradiologists, neurosurgeons, neurologists, fellowship trainees, postgraduate & graduate students. .