Tumor is an uncontrolledgrowth of cancer cells in anypart of the body. Tumors are of different typesand havedifferent characteristics and different treatments1.

Atpresent, braintumors are classified as primary braintumors and metastatic brain tumors. Theformer beginin the brain and tend to stay in the brain, the latter beginas acancer elsewhere in the body and spreading to thebrain.Brain tumors are dividedinto two types: benign andmalignant. In fact, themost widely used gradingschemehas been issued by the World Health Organization(WHO)2. It classifiesbrain tumors into grade I to IVunder the microscope. In general, grade I andgrade IIare benign brain tumor (low-grade); grade III and gradeIV are malignantbrain tumor (high-grade). Usually,if low-grade brain tumor is not treated, itis likelyto deteriorate to high-grade brain tumor. The 2012CBTRUS (CentralBrain Tumor Registry of the UnitedStates) Statistical Report has also showedthat braintumors are the second leading cause of cancer-relateddeaths inchildren under age 20 and in males ages 20-39 (leukemia is the first) and the fifthleading causeof cancer-related deaths in females ages 20-39.

Anestimated 69 720new cases of primary brain tumorswere expected to be diagnosed in 2013 andincludedboth malignant (24 620) and non-malignant (45 100)brain tumors. Thisestimate is based on an applicationof age-sex-race-specific incidence ratesfrom the 2013CBTRUS Statistical Report using SEER and NPCRdata to project 2013US population estimates for therespective age-sex-race groups(www.abta.org/about-us/news/brain-tumor-statistics/). Therefore, brain tumorsareseriously endangering people’s lives and earlydiscovery and treatment havebecome a necessity. Inthe clinical aspect, treatment options for braintumorinclude surgery, radiation therapy or chemotherapy.Along with the advanceof medical imaging,imaging modalities play an important role in theevaluationof patients with brain tumors and havea significant impact on patient care.