How does Siddhartha Mukherjee use imagery in The Emperor of All Maladies: A Biography of Cancer?

Imagery:

"For an oncologist in training, too, leukemia represents a special incarnation of cancer. Its pace, its acuity, its breathtaking, inexorable arc of growth forces rapid, often drastic decisions; it is terrifying to experience, terrifying to observe, and terrifying to treat." Prologue, p. 3

"In the late 1940s, a cornucopia of pharmaceutical discoveries was tumbling open in labs and clinics around the nation."