Sunday, September 12, 2010

Pet Scan Results

A PET, which stands for positron-emissions tomography, scan is used to detect cancer in patients. A PET scan can locate cancer, give information on the stage of the cancer and monitor how well treatments are working for current cancer patients. PET scans can even diagnosis benign or cancerous tumors. When a doctor finds a lump in a lung, a PET scan may be able to tell whether surgery and treatment is necessary without having to do a traditional biopsy. PET scans work  by using a small amount of a radioactive tracer attached to glucose. The scanner finds areas in the body that are using more glucose and signifies that as a sign of cancer.
  1. Attend a PET/CT Image Interpretation training (see Additional Resources). PET scans should be read by professionals who have been trained (either through regular coursework or through specialized courses) to avoid unclear results or panic in the person who had the PET scan. Doctors should not hand over results without letting the patient know how to read the scan and what it means.

  2. Search the PET scan for hot spots if you are trained in reading PET scans. Hot spots will occur where the body is using more glucose.

  3. Use the Standardized Uptake Values (SUVs) scale to measure the brightness of a hot spot on a PET scan. The scale range is zero to 15. Zero indicates no uptake, and 15 is maximal uptake. Most cancers are above 2 or 3 on this scale.

  4. Decide if the SUVs are in the 2 to 3 SUVs range. If they are, discern whether the patient may have cancer or the hotspots may be a sign of highly metabolic normal tissues. Highly metabolic normal tissues can register in the 2 to 3 SUVs range also, but it would abnormal for this tissue to be closer to 15.

  5. Discuss the patient's options if any cancerous tumors are found in the body during the PET scan. PET scans can show that the tumor is benign or cancerous, and so a biopsy may or may not need to be scheduled for the patient.

CT Scan Radiation

Radiation from computerized tomography scans may cause cancer decades later, according to a study that estimated about 29,000 future malignancies would occur in the U.S. because of CT scans done in 2007.

Most of the cancers are predicted to strike women, who receive more CT scans than men, and about one-third of the projected malignancies may occur from scans performed in people ages 35 to 54, said research published today in the Archives of Internal Medicine. The cancer forecast was based on an estimate that about 72 million CT scans were done in 2007.

The number of CT tests in the U.S. has risen three-fold since 1993, according to the study. More research is required to determine the lowest dose of radiation needed for clear pictures from CT scans to help reduce radiation exposure, said lead study author Amy Berrington de Gonzalez.

“We know that there are great medical benefits to CT scans, but they also involve small risks of cancer because of radiation exposure,” said Berrington de Gonzalez, a researcher at the National Cancer Institute in Bethesda, Maryland, in a Dec. 11 telephone interview. “For an individual, the risks are small. So if the scan is clinically justified, then the benefits should outweigh the risks.”

CT scans produce detailed images of the body that provide more details than a traditional X-ray. CT scanners are made by Fairfield, Connecticut-based General Electric Co., Toshiba Corp. based in Tokyo, Munich-based Siemens AG and Royal Philips Electronics NV based in Amsterdam.

Medicare Data

Researchers in the study looked at data from Medicare, the U.S. government health program for those older than 65 or disabled, plus a survey and an insurance database with information on the types of CT scans and the age and gender of patients taking the tests.

Berrington de Gonzalez said the overall risk for any individual is small and depends on the type of scan given and a person’s age. A 70-year-old who has a CT scan of the head would have a 1 in 10,000 chance of developing cancer from the test, while a baby who had a chest CT scan would have a 1 in 200 chance, she said.

The researchers found that about 30 percent of scans in the study were performed in adults ages 35 to 54, 13 percent in those 18 to 34 and 7 percent in children younger than 18.

Lung Cancer

The authors predicted that lung cancer will be the most common radiation-related cancer followed by colon cancer and leukemia. Of the 29,000 people who may get cancer from CT scans done in 2007, about 50 percent will die, the researchers estimated. If CT scan use remains at its current level or higher, eventually 29,000 cancers every year could be related to past CT scan use. That number is equal to about 2 percent of the 1.4 million cancers diagnosed each year in the U.S., they said.

A second study in the journal found that radiation doses from CT scans vary greatly and are higher than previously thought. The researchers reviewed CT procedures performed on 1,119 patients in the San Francisco Bay area over five months.

They found a 13-fold variation between the highest and lowest radiation dose for each type of CT procedure. Patients’ exposure to radiation needs to be reduced by standardizing and limiting the radiation associated with each scan, they said. The number of CT scans should be reduced, they said, citing previous reports that 30 percent or more may be unnecessary.

The U.S. Food and Drug Administration issued interim regulations Dec. 7 requiring closer monitoring of CT scans after more than 250 cases of exposure to excess radiation were reported since October.

CT Heart Scans

The researchers, led by Rebecca Smith-Bindman at the University of California, San Francisco, also estimated cancer risk. They project that 1 in 270 women who undergo a CT scan of the heart’s blood vessels at age 40 will develop cancer from the procedure compared with 1 in 600 men.

In certain groups of patients for certain kinds of scans, the risk is as high as 1 in 80, said Smith-Bindman, a professor of radiology at UC San Francisco, in a statement. The risk of developing cancer declined “substantially” with advancing age, the authors said.

“It is imperative, particularly given these results, that we start collecting radiation dose data at the individual patient level,” Smith-Bindman said in a statement. “Our results point toward the need to start collecting data on what actually happens in clinical practice and then to establish the appropriate standards.”

Heart Scan|Cardiac CT Scan

Some doctors call the heart scan procedure the "mammogram of the heart" because of its capability of detecting heart disease at an early stage. However, other doctors feel that more studies should be conducted before this becomes a widely used screening technique.

The Heart Scan Procedure
The heart scan is a simple non-invasive test used for early detection of heart disease. With early detection and modifying your risk factors, the potential for advanced heart disease may be significantly reduced and in some cases reversed.

The heart scan is a painless test that takes about 10 minutes. The process is similar to taking an x-ray of your body. An individual lies on the scanner table and multiple images of the heart are taken. A qualified physician then interprets these images to determine the amount of calcified plaque in the arteries.

The heart scan may be appropriate for men 35 or older and women 40 or older with any one of the following risk factors. Younger individuals with any of the following risk factors may also be considered:

* High Blood Pressure
* High Cholesterol
* Diabetes
* History of tobacco use
* Family history of heart disease
* Overweight or obese
* Significant emotional or job-related stress

How does the Heart Scan detect Heart Disease?

Heart Scan Showing No Calcification.The heart scan does not determine whether or not you are going to have a heart attack. Rather, the heart scan detects calcified plaque in the arteries of the heart. Calcified plaque is an indicator of heart disease. Soft plaque or non-calcified deposits are also predictors of heart disease however, these cannot be detected by a Heart Scan or any other non-invasive test. So even if the Heart Scan determines that you do not have any calified plaque there is still a risk that you have soft plaque or non-calcified plaque.
Background on Heart Disease

Heart Disease is the #1 cause of death and disability in the United States. Unfortunately, in many cases, the first sign of heart disease may be a heart attack and possibly death.

Body ScanHeart disease and heart attacks are caused by a process called atherosclerosis, often referred to as "hardening of the arteries". As we grow older, cholesterol particles deposit themselves in the walls of our blood vessels. This gradual buildup of cholesterol is collectively referred to as "plaque". When plaque gets big enough, it can obstruct blood flow or it can become unstable and the plaque can rupture and cause a heart attack. This process of forming plaque occurs in almost everyone, often starting as early as the teen years. However, it usually takes many years before the plaques are large enough to actually cause a problem.

For more information on heart disease contact:

The American Heart Association is a national voluntary health agency to help reduce disability and death from cardiovascular diseases and stroke.

Why Get a Heart Scan?
A heart scan is used "screening" of heart disease and cancer. In medicine, "screening" means looking for a medical condition in a person showing no symptoms in the hope of identifying problems early, when treatment can be most effective. There are many screening tests that look for different abnormalities. For example, a very popular screening test for women is the mammogram. Most mammograms are done on women who do not have a lump in the breast or other evidence of breast cancer; it is done as a preventive measure in hopes of catching breast cancer at an early stage. The heart scan is based on the same theory - eary detection.

How long does a heart scan take?
The heart scan approximately takes about 10-15 minutes.
What is the cost of a heart scan?

The average cost of a heart scan is $500.

CT Scan Vs MRI Scan

 It is a general question what is the difference between CT Scan and MRI Scan. Often people thinks these are same but there are big difference between CT Scan and MRI. Let us find the solution of the problem.
1. What part of the body does your doctor want to see? AND
2. What's the reason for the exam?

CT Scan does not show you tendons and ligaments very well at all; at least not yet. MRI is the best choice for that. Tendons and ligaments around the shoulder and knee are best seen by the physics used in MRI. This is due to the density of the tissues that compose the tendons and ligaments.
Spinal cord is best seen by MRI for the same reason. The density of the spinal cord and the composition of it is such that MRI physics can show it to us much better than CT.
There are also reasons why CT is the exam of choice over MRI. It is the preferred modality for cancer, pneumonia, and abnormal chest x-rays. Bleeding in the brain, especially from injury, is better seen on CT than MRI. But a tumor in the brain is better seen on MRI.
If you've been in an accident, organs can get torn or damaged. CT shows organ tear and organ injury quickly and efficiently. Broken bones and vertebral bodies of the spine are better seen on CT but injury to the spinal cord itself is displayed on MRI far better than CT.
CT is far superior at visualizing the lungs and organs in the chest cavity between the lungs. MRI is not a good tool for visualizing the chest or lungs at all.



MRI vs CT scan depends on what needs to be visualized and the reason you need the test. Radiologists are the doctors that specialize in reading images of the body and therefore know which test is best for showing anatomy according to the reason for the exam. Very experienced CT and MRI technologists will also know from working with Radiologists. The difference in the way the images are produced in MRI vs CT is the physics involved. CT scan uses an x-ray beam that slices through you like a knife carving a spiral ham.
MRI ( magnetic resonance imaging) uses a magnetic field with radio frequencies introduced into it. When your body is placed inside the magnetic field, the molecules of water in your body (hydrogen molecules) will start to spin like a kid's top when he spins it. The top will begin to wobble as it slows down.
Your hydrogen molecules will start to wobble just like the top does at a certain rate of speed; the stronger the magnetic field, the faster they will wobble and the weaker the magnetic field, the slower they will wobble; it depends on the strength of the magnetic field.
Then a radio frequency is introduced into the magnetic field at the same rate of speed at which the "tops wobble" causing the wobbling tops and radio frequency to sing out together sharing the same signal frequency. (Thus the term resonance) That signal is used by the MRI computer to produce the image.

MRI is the one that has the longer shape to it like this.

CT scanners have more of a donut shape like this.


64 slice CT scan

 64 slice CT scanner?

In computed tomography (CT) scanning, x-rays obtain image data from different angles around the body and then are processed by a computer. The images are 3 dimensional in nature and provide good resolution. The CT is an excellent technique to make a diagnosis of disorders in many different parts of the body, however, because the heart is constantly beating, CT scan could never be used to image it in the past.
Until the past few years, the technical gold standard was 16-slice CT scan, which required the patient to hold their breath for 25- to 40-seconds in the time it took to perform the scan. Today, the 64 slice CT scanner can perform the same task in just a few seconds and the images are much better.
The speed of the 64-slice CT scanner can gather a high-resolution image of a heart, brain or both lungs in less than five seconds. A scan of the whole body is possible in about 30 seconds. The speed of the 64 slice CT scanner has also allowed for the technology to be an alternative to conventional angiography or cardiac catheterization. The procedure is less invasive and produces excellent imaging.

What is the biggest advantage of a 64 slice CT Scanner?

Today, the only way to confirm the presence of coronary artery disease is to get what is called a cardiac catheterization. This invasive procedure requires a large amount of dye, large needle in the groin, bed rest for 6-8 hours and an overnight stay in the hospital. The 64 slice CT scanner is so fast that it can image the heart and the coronary vessels in a few seconds. This latest generation scanner is able to non-invasively capture images of any organ in one second and capture images of the heart and coronaries in fewer than five heartbeats, something no other CT system can offer.
Because the 64 slice CT scanner has only been recently available, its use in the evaluation of the heart has been limited. However, there is no doubt that it will soon replace cardiac catheterization for many elective cases.
Heart catheterization is a very commonly performed test that is safe and provides very accurate information. But, it is still an invasive test, which is one reason why this technology is being studied.

What information can be provided by a CT cardiac scan?

Because of the extremely fast speed of the scanner and the latest computer technology, one can obtain images of the heart in multiple dimensions. The coronary vessels can be visualized and the presence of any blockage easily seen.
The 64 slice CT scanner provides images of the heart in between each contraction, without causing any blurring of the images.

How is the 64 slice CT heart scan done?

The best heart views are obtained with a slow heart rate. Thus, some doctors will give a medication to slow the heart just prior to the procedure. The patient lies down flat on the table and the CT scan is done. The 64 slice CT scan is so fast that the entire heart is imaged in less than 15 seconds. The patient then goes home.

When can the results be available?

If prior arrangements have been made with a radiologist, the images can be read right after the scan and be ready in 30 minutes.

Who is a candidate for a 64 slice CT scan?

  • those individuals with the lowest risk of heart disease
  • young patients with questionable heart disease
  • young patients with congenital heart problems
  • individuals with an abnormal stress test and a low risk for heart disease
  • patients with atypical chest pain and low likelihood for heart disease
  • individuals with disease in their carotid arteries
  • individuals with a stroke
  • individuals with a blood clot in the lung (pulmonary emboli)
  • individuals with cancer

What are the benefits of a 64 slice CT SCAN?

  • The unprecedented coverage speed of this system allows physicians to capture a high-resolution image of the heart in 5 beats, or go head to toe in less than 10 seconds - faster than any other CT scanner on the market today.
  • This pain-free procedure offers exceptional image quality which can mean better physician diagnosis, faster recovery time and increased patient comfort and convenience.
  • By providing a non-invasive study that can quickly distinguish blocked from normal coronary arteries, it can determine who is and is not at high risk of having a heart attack. This can reduce the time a patient must spend in the emergency department, or eliminate the need for hospitalization, if the exam is normal.
  • Unlike conventional angiogram, the needle is placed in the hand and not in the groin.
  • Unlike cardiac catheterization, this is an outpatient procedure.
  • The complications of the procedure itself are much less than that of a cardiac catheterization.
  • For those who have back or neck pain, this technique is much easier than a cardiac catheterization as the procedure takes a few seconds.

What are limitations of a 64 slice CT SCANNER?

Although the scanner table is built to support up to 450 pounds, it can be difficult to accommodate patients who are morbidly obese.
The CT scanner is not the best at identifying calcium precipitates around the blood vessels and may fail to detect the presence of a plaque.
In addition, if an individual has a coronary stent placed, the CT scan is unable to detect the presence of any narrowing inside the stent.
The presence of mechanical heart valves, pacemaker leads and any other foreign body around the heart can interfere with the quality of the image.
Each scanner costs between $1.5 million to $2 million.
It does have radiation exposure and may not be suitable for pregnant females.

PET Scan Lung Cancer

Lung cancer accounts for the most cancer-related deaths in both men and women.

More people die of lung cancer than of colon, breast, and prostate cancers combined.
In 2009, there will be an estimated 219,440 new cases of lung cancer in the United States: 116,090 cases among men and 103,350 among women, according to the American Cancer Society.
**Experts predict that this year about 159,390 people will die of lung cancer.
Lung cancer may take many years to develop--it is a silent killer because it can grow for a long time before it is found. Once the lung cancer occurs, cancer cells can break away and spread to other parts of the body (metastasis). Lung cancer is such a deadly disease because it often spreads before it is found.
Most patients are between 55 to 65 years old when they are diagnosed. Sadly, the overall survival for 5 years in patients with the different types of lung cancer is less than 10%. However, when lung cancer is found early enough for surgery to remove it (before it has spread to other organs), patient 
 

There are many types of lung cancer, but most belong to one of two types:
  • Small cell lung cancer (SCLC) - Although the cancer cells are small, they spread quickly to form large tumors that then can progress to other parts of the body, including lymph nodes, brain, liver, and bones.
  • Non-small cell lung cancer (NSCLC) - This is the most common type of lung cancer and incorporates several different sub-types: Squamous cell, adenocarcinoma, and large cell. These types may also spread quickly to other parts of the body.
Although most lung cancers do not cause symptoms until they have spread, some of the most common early symptoms may be:
  • A cough that does not go away
  • Bloody or reddish colored mucous that is coughed up
  • Shortness of breath or wheezing
  • Chest pain
  • Hoarseness
  • Rapid loss of weight; loss of appetite
If lung cancer is found, prompt treatment could save your life.
Since most people with early lung cancer do not have any symptoms, only about 15% of lung cancers are found in the early stages. When lung cancer is found early, it is often because a chest x-ray, CT scan, or other test was being done for another reason.
This is where PET Scanning can help.
If your doctor suspects that you might have or be at risk for lung cancer, he/she will most likely talk to you about your medical history and do a physical exam. To get pictures of your lungs, your doctor might want to do an imaging test, such as a PET scan.
Lung masses are usually first evaluated through a chest x-ray or a CT scan. These tests can provide information regarding the size and location of a lung mass but most often they cannot tell if the abnormality is benign or cancerous. Solitary pulmonary nodules and other lung masses can be screened with high accuracy using PET.
PET scans, now available at the PET centers nearest you are a new test that help doctors learn more about the tumor-maybe even preventing an unnecessary biopsy. Click here for information about whether you might be a candidate for PET or to schedule a PET Scan.


Treatment

The doctors diagnose the cancer and determine what kind it is by looking at a sample of the tumor under a microscope. This alone does not determine what treatment you can have. Before treatment, your doctors must determine if or how much the lung cancer has spread. This is called staging the cancer.
The outlook for your recovery and your treatment options, which may include surgery, radiation therapy or chemotherapy depend upon the stage of the cancer. If lung cancer is found and treated with surgery before it has spread to lymph nodes or other organs, the five-year survival rate is about 42%. Knowing accurately whether you are a candidate for surgery is critical at this early point in time.
PET is the most useful test that you can have when doctors are staging or re-staging lung cancer because it is more accurate than CT or any other test. 

How PET works:
In cancer, cells begin to grow at a much faster rate, feeding on sugars like glucose. PET works by using a small amount of a radioactive drug called a tracer in combination with a compound such as glucose. Once you are injected with the tracer and glucose, the tracer travels through your body. It emits signals as it travels and eventually collects in the organs targeted for examination. If an area in an organ is cancerous, the signals will be stronger since more glucose will be absorbed in those areas.
In the lungs, if the cancer has affected the nearby lymph nodes, they will take up more of the radioactive glucose. Whether or not lymph nodes are involved is a critical factor in deciding whether you can have surgery to remove the lung cancer. CT scanning which looks at the size of the lymph nodes, on average is only about 68% accurate in determining if the lymph nodes have been affected. PET is more than 82% accurate in determining the same thing. In the same whole-body picture, the PET scan can look throughout your whole body to see if there are any clumps of the cancer cells that have spread. The PET scan can make the difference in your recovery.
The type of treatment that can be done is based on both type of cancer cells and the stage. If the tests show that the cancer has not spread too far when it is first found, then surgery to remove it is done. Along with the surgery, your doctor may also recommend chemotherapy and/or radiation therapy as well.
In general, however, if the cancer has spread, it is treated by chemotherapy and/or radiation therapy. Lung cancer can spread to nearly anywhere in the body, but most commonly it spreads to the brain, bone and liver. After first showing the doctors where the cancer cells are, PET can also see if the chemotherapy and/or radiation therapy has been effective in killing them.
Call the doctors at the PET centers nearest you if you have lung cancer and would like to discuss whether PET would be useful in your care. 

Follow-up

After treatment, it is important to know if any active cancer cells remain in the body. In the past, the amount and type of chemotherapy that is used, as well as the area treated by the radiation beams in radiation therapy, was according to standard rules. PET allows the type and amount of therapy to be directed specifically to you, the patient, and the location, extent, and resilience of your type of cancer.
PET can be used to image lung tumor response to therapy and to detect recurrence in successfully treated lesions.
If the cancer cells have been killed by the treatment, they will not absorb any of the radioactive glucose given in the PET scan. After treatment, although the tumor masses may still be present and seen on CT scans, the cells may no longer be alive-which can be shown by PET. Conversely, if the cancer cells have come back either in lymph nodes or scar tissue from surgery or another lesion, PET can see the accumulation of the radioactive glucose much sooner than a CT scan-treatment can be re-started sooner and this can improve your chance of beating this disease.
Call the doctors at the PET centers nearest you if you have lung cancer and would like to discuss whether PET could be useful in your care.

Body Scan|Full Body CT Scan


Full body scanning gets much of the attention as it is keyed to disease screening. The medical imaging method most frequently under discussion is Electron Beam Tomography, EBT, for "full body" scans. However,  CT Scans, employing a computer helical CAT scan is also used for a wide range of body screening. It may also be referred to as "spiral scanning." Both are rapid and non-intrusive for the patient and provide almost immediate results.

In the EBT process, the patient lies on a table fully-clothed and an electron beam traverses the body area in seconds. Exposure to radiation is minimal and produces 3-dimensional images for examination by the technician or physician. The exceptionally detailed graphics may be viewed from every possible angle and images may be stored, filmed or transmitted.

In spiral CT scans, the x-ray tube rotates around the reclining patient as the examination table moves forward through the scanner. Since the tube is rotating while the patient moves through the x-ray it provides a spiral view of the body and thus derives the term for the scan. The process is rapid and efficient and may be applied from head to toe.

In EBT scanning, the term "full body scanning" has been applied to a scan of the vital organs. The body area covered in the scan extends from the neck and shoulders to the top of the hips.

EBT is now one of the major screening devices for the detection of coronary artery disease. Faster than the basic CT scan, EBT has been approved by the FDA and is considered ideal for early detection of calcification in coronary arteries. The screening allows physicians to act promptly to initiate preventive measures that might not ordinarily be revealed in early stages of a disease.

FDA has cleared full body scanning for early lung cancer detection. Many forms of tumors, intestinal irregularities, and disorders of the liver and kidney's may also be found at early stages, allowing for prompt attention.

Risks of Full Body CT Scan

People should be aware of the risks associated with full body CT scans (also known as CAT scans) and virtual colonoscopy. Full body scans, promoted in most hospitals now as a new preventative health screening service available to the public, involve doses of radiation that health experts do not consider to be justifiable in terms of a health check.
An investigation by most hospitals nowHealth and the Environmental Protection Authority (EPA) found people can be exposed to dangerously high levels of radiation, sometimes up to 500 times more than a standard chest x-ray, for no gain at all.

It is important to distinguish between CT scanning as a screening tool, and CT scanning for diagnostic investigation. 

This warning applies to the use of CT scanning in people with no symptoms, or with symptoms that have not been assessed by a General Practitioner.
In other patients, CT scanning is one of many useful investigations available to explore symptoms or monitor the progress of significant diseases, with the radiation dose involved in a conventional diagnostic scan deemed to be justified by the health benefits that may arise from the diagnosis.
However full body CT scans as a health check up are unproven and no studies have been completed to support their use for this purpose.
Leading Australian and international authorities on radiation technology do not support CT body scans as a preventative screening tool.
Another recently developed application of the CT scanner is virtual colonoscopy. While this test has some use in the investigation of people with a risk of bowel cancer, it should only be undertaken after consulting with a general practitioner or gastroenterologist to consider the most appropriate method of investigation for an individual.
According to the International Commission on Radiological Protection, a full CT body scan examination with an effective dose of 10 millisieverts may be associated with an increase in the possibility of developing a fatal cancer of approximately 1 in 2,000.
This small increase in radiation-associated cancer risk for an individual can become a public health concern if large numbers of the population undergo increased numbers of CT scans of uncertain benefit.
The independent Radiation Advisory Council that advises the EPA and most hospitals now Health on radiation matters, raised the following issues in relation to full body CT scans:
  • The procedure has no proven benefit and has not been shown to identify small cancers.
  • A medical practitioner should refer people for such a procedure if there is a real need.
  • The results may be unreliable, especially if there has been no medical management prior to the scan.
  • The potential radiation dose could be significant and pose long-term health risks.
CT scan operators who rely on advertising for business are subject to the following license conditions:
  • Consumers will need an independent doctor's referral before undergoing a full body scan.
  • Body scan operators must fully inform consumers about the risks of procedures, including the scale of the radiation dose, the inconclusive nature of the results and the risk for people under the age of 50 of developing cancer as a result of the procedure.
  • Consumers are obliged to sign a declaration stating they have received such advice.
CT scans have an important role to play in the medical setting and should be used in accordance with professional medical advice. Consumers have a right to know that to use full body scans or virtual colonoscopy as a screening tool may increase their risk of cancer.