I wish I had an angel today. I went to see a ear specialist to find out about my tinnitus problem. I was hoping that
she would say that it was ear was. But my ear was clean. After she checked to see if I had sinus and did some test, she said she would me sending to ultra sound and to MRI to see what's happening inside my head. Meanwhile, I have to learn with a new norm to live with constant swooshing sound in my ear, especially need to learn to sleep while I am hearing the nose. A small plus is that I don't have to wear an extra wrist band to check my heart rate as I hear it all the time. The truth is I am still assessing the situation. My emotion is up and down.
PET
So, we know mitochondria consumes glucose (someone say sugar) and generates energy for all chemical reactions
in our body. Top layer cells of bladder epithelial cells need to be replaced with new cells every 40 days because of tear and wear due to sodium, chlorine and toxin in urine and due to expansion and contraction. So, mitochondria needs to generate energy for a cell division every 40 days. Cancer cells lost a sense of when to rest, so they divide without stop. Mitochondria consumes more glucose and generate more energy to support proliferation of the cancer cells. PET uses this phenomena to see how active cancer cells are by checking how much glucose are being consumed by mitochondria. PET is short for Positron Emission Tomography. I will explain it in more detail later but the point is that just before you go into a PET machine, you will be intravenously injected with glucose (sugar). The injected glucose will be delivered to all of your body including cancer cells and surrounding normal cells through blood vessels. The area where the more cells are dividing, multiple mitochondria in those cells are consuming glucose. If there is a machine to detect how much glucose consumption is happening, not only the machine should be able to detect where cancers are located and how fast cancers are growing and how slow cancers are growing. This is what PET does. The problem is that PET is not designed to detect glucose consumption activities directly. So, something to emit positron is added to glucose. This positron collides with
an electron and vanishes after emitting 511 keV gamma photons. PET can detect those gamma photons, thus will know where in the body the positron existed. That is where glucose was consumed/mitochondria of a cell is located.
The risk is absorbed radiation doses when Fludeoxgenglucose F18 ( this is glucose with Fluorine isotope F18) is injected to our vein.
I have tried to come up with the risk of PET in terms of radiation below. But, I could not totally wrong.
FDA report says for adult (70kg), with one pet scan, 0.32 rem/Ci radiation is absorbed in the bladder wall.
0.32 rem/Ci is the same as 0.0032 or 3.3mSV
Radiation absorption from chest Xray is 0.1mv, which is equivalent of being outside 10 days.
Radiation absorption from CT scan of abdomen and pelvis is 10 mSV, which is equivalent of 100 Xray or 1000 days being outside.
Radiation absorption to bladder wall is 3.3mSV, which is equivalent of 33 times of Xray or 1/3 of CT scan, or 330 days of being outside.
It is noted infants absorb 10 times more radiation than adults.
the risk of CT scan will be covered late.
Attached are the molecule structure of Glucose and when Fluorine isotope F18 was bonded to make the contrast which is injected for PET scan and how a positron is generated and how it collide
with an electron and generate 511kev photons.
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