xvi Foreword The discipline of Radiology was born with the invention of x-rays by Roentgen in 1895. The field ex- perienced many technological revolutions in just the past four decades ­ CT, SPECT, PET, MRI, 3D Visualization, PACS, rapid advances in Ultrasonography, molecular imaging, and hybrid imaging strat- egies such as PET-CT and PET-MRI. Ironically, despite the computers playing a major role in image acquisition technologies, the practice of clinical radiology has remained mostly descriptive, subjective, and qualitative. It is widely recognized in the medical imaging field that turning this practice into Quan- titative Radiology will open numerous avenues for advances in medicine ranging from improved sensi- tivity, specificity, accuracy, and precision of early disease diagnosis, improved understanding of dis- eases and disease processes, more objective response assessment of disease following treatment, novel and more effective treatment regimens and procedures, and increased ease of disease measurement and