Algorithm - Book 1 - The Medallion

Chapter 14

Linda and Adam nodded in unison.

"Then you know that we apply an energy field, a radio-frequency field tuned to the energies of protons, to an object or a patient.  And by moving this field over the object and detecting how much of the field is absorbed by protons aligning with it, we detect those protons.  Thus, the instrument provides us with an image of the location of different types of protons in the sample."

He sure likes listening to himself.

Percy continued, "We can tune the field to a number of different types of atoms. Besides protons, other elements were susceptible to MRI imaging, and among these is carbon-13.

"So, you can get the MRI field to image carbon-13. But, these are very small particles. Is your instrumentation really that sensitive? Especially as the particles are embedded in gold?"

"Actually, gold, or any metal for that matter, usually presents a challenge. Although it's not magnetic, the applied rf field will generate Eddy currents in gold which can result in so much background noise that analysis becomes impossible."

Percy suddenly raised his hands in nerdly triumph. "However, we have a very sophisticated set of electronics here that can dampen those Eddy currents by pulsing the sample at the right frequency.  It's a question of whether we can generate a detection window wide enough to visualize the carbon-13."

"And what about the particle size? These are very small … maybe on a micron scale."

"That's where the TMS technology comes in."

Adam recalled the sign above the door.

Transcranial Magnetic Stimulation.

Percy arose, and beckoned the pair to follow him as he walked over to a corner of the laboratory.  What looked like a mini-MRI sat at the end of an elongated table. The silvery cylinder was the size and shape of a 1950s era beehive hair drier turned on its side, except this one had a chaotic array of multi-colored wires sprouting from its head. The sight made Adam look about the lab, half-expecting to see a hunchbacked assistant limping in through the doors.

"This little guy started out as a brain-scanning application. We now refer to it as a micro-MRI. It is capable of detecting and imaging very small particles, normally limited to a millimeter-sized resolution because of the inherent movement of live biological tissue."

"Like the brain in someone's head, for example," Adam offered.

A living brain, that is.

 "Exactly. However, in your case, the medallion is not going to move and we may be able to get the resolution down to micron levels."

Adam finished Percy's thought aloud. "Small enough to get a clear picture of the C-13 patterns in the medallion."

***

Linda and Adam were purchasing coffee from a vending machine in the hallway when an undulating and ear-splitting screech cut off their conversation.  Next, an overly loud mechanical voice blared instructions for everyone to calmly proceed to their designated safe zones.  Not knowing where their safe zones might be, they started back to the TMS lab when Percy appeared in the hallway.  He waved for them to follow him to a heavy metal door emblazoned with the universal black and yellow pie-wedge radioactivity logo and big black letters spelling out "SHELTER."  A number of other scientists and technicians were fast-walking their way in the same direction. They descended the stairway to a large and windowless basement room. The blaring above them continued interspersed by a calm robotic warning. Then silence.