Jiang Du – MRI of Short and Ultrashort-T2 Tissues

Автор: Jiang Du
Название: MRI of Short and Ultrashort-T2 Tissues
Формат: PDF
Тема: МРТ коротких и ультракоротких тканей Т2
Количество страниц: 612
Качество: Компьютерное, издательское

This book comprehensively covers ultrashort echo time (UTE), zero echo time (ZTE), and other magnetic resonance imaging (MRI) acquisition techniques for imaging of short and ultrashort-T2 tissues. MRI uses a large magnet and radio waves to generate images of tissues in the body. The MRI signal is characterized by two time constants, spin-lattice relaxation time (T1) which describes how fast the longitudinal magnetization recovers to its initial value after tipping to the transverse plane, and spin-spin relaxation time (T2) which describes how fast the transverse magnetization decays. Conventional MRI techniques have been developed to image and quantify tissues with relatively long T2s. However, the body also contains many tissues and tissue components such as cortical bone, menisci, ligaments, tendons, the osteochondral junction, calcified tissues, lung parenchyma, iron containing tissues, and myelin, which have short or ultrashort-T2s. These tissues are “invisible” with conventional MRI, and their MR and tissue properties are not measurable. UTE and ZTE type sequences resolve these challenges and make these tissues visible and quantifiable.