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Ok, this is another glossary quiz? (Remember me, I'm the dorky one that tried to use fake names and asked what was NED, tx & dx?) What is a PET scan? What are "hot spots" and "cold spots"? and What do you mean by the x-ray "lighting up"? I'm assuming hot spots and lighting up probably mean cancer, but do they relate to a certain type of cancer? or to a certain type of scan?

Peggy (really, really - but he's still gotta be Tony for now)

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I, too, am still trying to figure out what some of the terms are (PCI, COPD, and WBRT, for example).

PET scan: (from http://www.radiologyinfo.org/content/petomography.htm)

What is Positron Emission Tomography?

Positron emission tomography, also called PET imaging or a PET scan, is a diagnostic examination that involves the acquisition of physiologic images based on the detection of subatomic particles. These particles are emitted from a radioactive substance given to the patient. The subsequent views of the human body are used to evaluate function.

What are some common uses of the procedure?

PET scans are used most often to detect cancer and to examine the effects of cancer therapy by characterizing biochemical changes in the cancer. These scans are performed on the whole body. PET scans of the heart can be used to determine blood flow to the heart muscle and help evaluate signs of coronary artery disease. Combined with a myocardial metabolism study, PET scans differentiate non-functioning heart muscle from heart muscle that would benefit from a procedure, such as angioplasty or coronary artery bypass surgery, which would re-establish adequate blood flow. PET scans of the brain are used to evaluate patients who have memory disorders of an undetermined cause; who have suspected or proven brain tumors; or who have seizure disorders that are not responsive to medical therapy, and therefore, are candidates for surgery.

How should I prepare for the procedure?

PET is usually done on an outpatient basis. Your doctor will give you detailed instructions on how to prepare for your examination. You should wear comfortable, loose-fitting clothes. You should not eat for four hours before the scan. You will be encouraged to drink water. Your doctor will instruct you regarding the use of medications before the test.

Note: Diabetic patients should discuss specific diet guidelines to control glucose levels during the day of the test.

What does the equipment look like?

You will be taken to an examination room that houses the PET scanner, which has a hole in the middle and looks like a large, doughnut. Within this machine are multiple rings of detectors that record the emission of energy from the radioactive substance in your body. While lying on a cushioned examination table, you will be moved into the hole of the machine. The images are displayed on the monitor of a nearby computer, which is similar in appearance to the personal computer you may have in your home.

How does the procedure work?

Before the examination begins, a radioactive substance is produced in a machine called a cyclotron and attached, or tagged, to a natural body compound, most commonly glucose, but sometimes water or ammonia. This process is called radiolabeling. Once this attached substance is administered to the patient, the radioactivity localizes in the appropriate areas of the body and is detected by the PET scanner.

Different colors or degrees of brightness on a PET image represent different levels of tissue or organ function. For example, because healthy tissue uses glucose for energy, it accumulates some of the radiolabled glucose, which will show up on the PET images. However, cancerous tissue, which uses more glucose than normal tissue, will absorb more of the substance and appear brighter than normal tissue on the PET images.

Scientifically speaking, the radioactive substance decay leads to the ejection of positive particles called positrons. A positron travels about one to two millimeters before colliding with an electron. The collision results in a conversion from mass to energy, resulting in the emission of two gamma rays heading off in exact opposite directions. Special crystals, called photomultiplier-scintillator detectors, within the PET scanner detect the gamma rays. The scanner's special camera records the millions of gamma rays being emitted, and a connected computer uses the information and complicated mathematical formulas, called algorithms, to map an image of the area where the radioactive substance has accumulated.

How is the procedure performed?

A nurse or technologist will take you into a special PET examination room. You will lie down on an examination table and be given the radioactive substance as an intravenous injection (although, in some cases, it will be given through an existing intravenous line or inhaled as a gas). It will then take approximately 30 to 60 minutes for the substance to travel through your body and be absorbed by the tissue under study. During this time, you will be asked to rest quietly in a partially darkened room and to avoid significant movement or talking, which may alter the localization of the administered substance. After that time, scanning begins. This takes an additional 30 to 45 minutes.

Some patients, specifically those with heart disease, may undergo a stress test in which PET scans are obtained while they are at rest, then after undergoing the administration of a pharmaceutical to alter the blood flow to the heart.

Usually, there are no restrictions on daily routine after the test, although you should drink plenty of fluids to flush the radioactive substance from your body.

What will I experience during the procedure?

The administration of the radioactive substance will feel like a slight pinprick if given by intravenous injection. You will then be made as comfortable as possible on the examination table before you are positioned in the PET scanner for the test. You will be asked to remain still for the duration of the examination. Patients who are claustrophobic may feel some anxiety while positioned in the scanner. Also, some patients find it uncomfortable to hold one position for more than a few minutes. You will not feel anything related to the radioactivity of the substance in your body.

Who interprets the results and how do I get them?

Patients undergo PET because their referring physician has recommended it. A radiologist who has specialized training in PET will interpret the images and forward a report to your referring physician. It usually takes one to three days to interpret, report, and deliver the results.

What are the benefits vs. risks?

Because PET allows study of body function, it can help physicians detect alterations in biochemical processes that suggest disease before changes in anatomy are apparent on other imaging tests such as CT or MRI scans.

Because the radioactivity is very short-lived, your radiation exposure is extremely low. The substance amount is so small that it does not affect the normal processes of the body.

The radioactive substance may expose the fetus of patients who are pregnant or the infants of women who are breast-feeding to the radiation. The risk to the fetus or infant should be considered related to the potential information gain from the result of the PET examination.

What are the limitations of Positron Emission Tomography?

PET can give false results if a patient's chemical balances are not normal. Specifically, test results of diabetic patients can be adversely affected because of blood sugar or blood insulin levels.

Also, because the radioactive substance decays quickly and is effective for a short period of time, it must be produced in a laboratory near the PET scanner. It is important to be on time for the appointment and to receive the radioactive substance at the scheduled time. PET must be done by a radiologist who has specialized in nuclear medicine and has substantial experience with PET. Most large medical centers now have PET services available to their patients. Medicare and insurance companies cover many of the applications of PET, and coverage continues to increase.

Finally, the value of a PET scan is enhanced when it is part of a larger diagnostic work-up. This often entails comparison of the PET scan with other imaging studies such as CT or MRI.

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Thank you, Melinda. I can't believe you put in the time to look at the big explanation for me. That was really a very, very nice thing to do. I do know 2 out of 3 of the acronyms you listed. COPD is chronic obstructive pulmonary disease, which is usually (but not always) emphysema or chronic bronchitis. My dad has severe COPD, and is in fact hospitalized on a ventilator with that disease right now. WBRT is whole brain radiation treatment. This was the very first treatment my husband received (daily for 2 wks) because this was really the only place he was symptomatic. I looked up PCI last week, but I've already forgotten what it stands for. I just read your MIL's history. Boy, she really has a lot of areas to be treated! How is she coping with so much all at once? It also looks like it was all discovered in such a short period of time, and then you mother is also having trouble. You and Geoff look very, very young. How are the two of you coping with all of this?

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Hi Peggy,

First I wish to welcome you to the place non of us really wish to be. Second I want to say, your HELLARIOUS! TOO TOO FUNNY!! I've been laughing at most of your posts, (now doesn't that sound SICK?) Not the important parts of your post.

Third, I wish to help you to learn about PET scan's and all that stuff you are having a heck of a time trying to put two and two together. At the top of each page you will see (WORDS) Like, Home, FAQ, Seach, GLOSSARY Yes, Glossary. If you click on that, you might be able to find some of these words and meanings right at your fingertips. :P But, then again, you always have US to ask as well. And that's why we're here! ((((((((PEGGY))))))) (this is a cyber hug)

So on that note, stay with us and you'll find a lot of information and support right here.

Wishing you and "Tony" a better tomorrow!

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Hi Peggy,

Sorry to hear about Tony. Here is a list of some websites that you might find helpful. I found the more I know and understand, the better off I am as I go along. Stay with us. Great place with great people. Lots of information, sharing and caring. Hope this helps. My thoughts and prayers are with the both of you. Peace, take care and God Bless.


[The Power Of People Helping People / The Power Of Knowledge / The Power Of God / The Power Of Believing / The Power Of Positive Thinking / The Power Of Never Taking No For An Answer / The Power Of Laughter / United We Stand, Divided We Fall / That’s The Key]

http://www.ncbi.nlm.nih.gov/entrez/quer ... h&DB=books (NCBI / BookShelf)

http://www.lungcanceronline.org/tests/index.html (Lung Cancer Online / Test And Procedures)

http://www.vh.org/adult/patient/cancerc ... index.html (Understanding Blood Tests / A Guide for Patients with Cancer)

http://www.cancer.gov/cancerinfo/pdq/tr ... ng/patient (SCLC)

http://www.meds.com/pdq/smallcell_pat.html (Medicine OnLine / SCLG)

http://health.allrefer.com/health/prima ... -info.html (Diseases And Conditions / SCLC)

http://www.hospicefoundation.org (Hospice Foundation Of America)

http://www.hospiceweb.com (Hospice Web)

http://www.hospice-america.org/consumer.html (Hospice Association Of America)

http://www.hospicenet.org (Hospice Net)

http://www.plwc.org/plwc/MainConstructo ... 151,00.asp (PLWC Feature: Talking to Someone With Cancer)

http://www.zanesvilletimesrecorder.com/ ... 87526.html (3-year-old keeps her smile in battle with rare cancer)

http://www.rfalung.com (Radio Frequency Ablation Of Lung Cancer)

http://www.lungcancercoalition.org (Global Lung Cancer Coalition)

http://www.plwc.org/plwc/MainConstructo ... 008,00.asp (PLWC Feature: Financial Support Resources)

http://www.usnews.com/usnews/nycu/healt ... hqcanc.htm (Best Hospitals)

https://www.alcase.org/advocacy/sign_the_petition.html (Advocacy /Sign the Petition)

http://www.cancersymptoms.org (Oncology Nursing Society)

http://www.plwc.org/plwc/MainConstructo ... 008,00.asp (Questions to Ask the Doctor)

http://www.alcase.org/education/publica ... reath.html (With Every Breath A Lung Cancer Guidebook / From ALCASE / A Wealth Of Information / Free)

http://www.cancersurvivaltoolbox.org (The Cancer Survival Toolbox / Free / From NCCS)

http://www.centerwatch.com (Clinical Trails Listing Service / Center Watch)

http://news.google.com/news?hl=en&editi ... ung+cancer (Lung Cancer In The News)

http://www.thewellnesscommunity.org/pro ... /guide.asp (The Wellness Community / National Cancer Support, Education And Support / Free)

http://www.drugs.com (Drug Information Online)

http://www.alcase.org (ALCASE / Alliance For Lung Cancer Advocacy, Support, Education)

http://www.nlm.nih.gov (Unites States / National Library Of Medicine)

http://www.nlm.nih.gov/medlineplus/encyclopedia.html (Health Information / Medical Encyclopedia)

http://www.google.com (Great Search Engine)

http://blochcancer.org (R.A. Bloch Cancer Foundation, Inc. / Please read: A Letter to all newly diagnosed cancer patients)

http://www.cancer.org (American Cancer Society)

http://www.cancer.gov (Cancer Information Service / NCI)

http://www.cancerresearchcenter.org (Cancer Research Center)

http://www.aicr.org (American Institute for Cancer Research; Nutrition Hotline / AICR)

http://www.cancerhopenetwork.org (Cancer Hope Network)

http://www.acor.org (Association of Cancer Online Resources / Free Online Lifeline For Everyone Affected By Cancer & Related Disorders)

http://www.meds.com/lung/lunginfo.html (Lung Cancer Information Library)

http://www.lungusa.org (American Lung Association)

http://www.ama-assn.org (American Medical Association)

http://www.docguide.com/news/content.ns ... g%20Cancer (Doctor’s Guide / Lung Cancer)

http://www.healthfinder.gov/Scripts/Sea ... ?topic=506 (Healthfinder)

http://www.medicinenet.com/Lung_Cancer/article.htm (Medicine Net)

http://www.cancerindex.org/clinks2l.htm (Cancer Index / Lung Cancer Resources Directory)

http://www.nfcr.org/site/PageServer?pag ... ncers_lung (National Foundation For Cancer Research)

http://www.patientadvocate.org (Patient Advocate Foundation)

http://www.lungcanceronline.org/effects ... fects.html (Lung Cancer Online / Hematologic (Blood) Effects)

http://www.cancerlinks.org/lung.html (Lung Cancer Links)

http://www.cancer-free.com (Cancer Free Connections)

http://www.healthinsite.gov.au/topics/C ... ung_cancer (Health Insite)

http://www.lungcancerclaims.com (Lung Cancer / Lung Cancer Information Page)

http://www.cancerlifecenter.com/engine. ... =dictionar (Cancer Life Center/ Cancer Dictionary)

http://www.canceryellowpages.com/Resour ... G%20CANCER (Cancer yellow Pages)

http://icare.org (ICARE / The International Cancer Alliance)

http://www.vh.org/index.html (Virtual Hospital)

http://www.lungcanceronline.org/support/financial.html (Lung Cancer Online / Financial, Legal & Insurance Issues)

http://cancernews.healthology.com/focus ... cancernews (Cancer News)

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