What is the difference between a CT and a PET-CT scan?


CT and PET-CT scans are very common procedures that doctors administer every day to help localize their examination and to provide the most thorough diagnosis. Both procedures contain varying, minimal risks but can provide huge benefits for patients that need a more in-depth examination and specialized treatment.

What is a CT scan?

A CT scan or a Computed Tomography scan is a medical procedure that uses x-ray radiation and fascinating computer technology to create cross-sectional images of the body’s organs and tissues. CT scans can also be called CAT or Computed Axial Tomography. CT scans take helical images of the examined part of the body which produces better 3-dimensional imaging. The better the image, the better the diagnosis your doctor can make. CT scans are particularly useful in the examination of tissues, cancer staging, and determining vascular disease.

What is a PET-CT scan?

A PET-CT scan or Positron Emission Tomography is a medical procedure similar to a CT scan but PET-CT scans are commonly used in determining the difference between healthy and diseased tissue. Using nuclear medicine these exams allow particular focus on oncological symptoms in the brain and heart as well as any vascular or tissue abnormalities.

What are the procedures like?

The biggest difference between a CT and a PET-CT scan is the machinations of the procedure. There are varying states of discomfort between both procedures, but both are relatively painless and easy to complete for any patient.

A CT machine looks like a large tire with the patient placed inside the “hole.” The patient is placed on the examination table and will be administered contrast material through the mouth or intravenously. The feet will be the first to enter into the machine and the body will be slowly moved into the chamber. The procedure lasts approximately 10-30 minutes. Patients typically report that they hear a slight whirring sound which is the machine rotating around them gathering imaging. The doctor will able to speak to you and you will be able to respond.

A PET-CT scan is similar to a CT scan in some ways but the biggest difference between the two is the instructions prior to the exam. Most doctors and facilities will request that a patient not eat at least 4 hours prior to the scan and to drink lots of water. The exam also lasts slightly longer at about 30-45 minutes. Contrast material is commonly used as well and will either be  administered through an IV or by inhalation. If the PET-CT scan is being administered because of possible heart disease, the patient will often be asked to perform a stress test. The body will be examined at rest and during exercise in efforts to determine any cardiovascular problems. You may also hear a buzzing or clicking sound during this procedure.

Which procedure is more painful?

Both procedures have a minimal amount of pain and discomfort. The most common complaint is concerning the IV injection site or a claustrophobic feeling. But the contrast material is necessary for properly determining the condition of tissues and veins as well as highlighting possible cancerous cells. Furthermore, the body moves through the machine. It only covers the area that will be examined — it does not encapsulate the entire body.

Are there any risks?

Doctors and imaging facilities have been able to minimize the risks surrounding these procedures to practically nothing. Both a CT and PET-CT scan use small amounts of radiation to image the examined area. If you are pregnant or could possibly be pregnant, you should let your doctor know. There is no medical evidence that the amount of radiation is dangerous for an unborn child. But if there is another safer method to examine, your doctor can help you understand your options. Also if you have any implanted devices, artificial body parts or features such as hearing aids or dentures, talk to your doctor about what needs to removed for the procedure.

Ready to make your appointment? You can use our request an appointment form online or just call us at 504-883-8111.

The History of Medical Imaging

The first X-RayMedical imaging is a form of technology that has revolutionized the medical field in the past century.  With these new innovations, doctors were able to elevate the standard of practice and the experience of the patient. Now, areas of pain or trouble can be non-invasively examined and treatment can begin without the patient even needing to go under. But when did the innovation of medical imaging begin?

Read below to take a trip down memory lane and find out how the medical field and the technology industry have been working together to build a better, healthier world.

Röntgen performs X-Ray in 1895

Professor Wilhelm Röntgen accidentally discovers the ability to look through the skin and see the bones of the body while performing experiments on another project. While working with a cathode ray generator, he noticed an image that was left when the cathode rays came into contact with the vacuum tube. He performed the first X-ray on his wife’s hand and even gave the technology the name we use today, calling this discovery “X” rays because they were unsure what exactly they were. This invention was eventually standardized by William Coolidge and his X-ray known as the “Coolidge tube” is what all modern X-ray machines are based from.  The first X-rays required at least 11 minutes of exposure to produce a quality image. Now X-rays take only a few seconds and they use about 2% of the radiation amount seen in the early 20th century machines.

Scientists Use Ultrasounds in the 1960s

The basics of sonar had been discovered and utilized during World War II as a form of maritime warfare. In the early 1960s, scientists discovered that sending sound waves into the body would bounce off the internal structures and then returned to the ultrasound machine to be reformatted into images for doctors to see. This allowed doctors to non-invasively search for tumors and other growths.

Damadian Discovers MRI in 1970

Dr. Raymond Damadian discovers that different animal tissues emit different signals, as well as that cancerous tissues, take much longer to return the signal sent through them. This is the basis for magnetic resonance imaging. In 1977, Dr. Damadian created the first full-body MRI machine which he named the “Indomitable.”

Hounsfield Invents CT Scans in 1972

The 1970s showed the first instance of computer technology mixing into the medical field with Sir Godfrey Hounsfield’s invention of the CT machine. He theorizes that you could see into an object if you took X-rays from different angles of the object through a machine that would appear as “slices” which could then be put together to form an image. With his idea, he formed the first “axial tomography” machine which we now know as the CT machine. In 1979, he received the Nobel Prize in Medicine and was later knighted by the British Royal Family.

Since then, all of these machines have entered into the digital age and are now updated with the latest technology available. This means that there is less potential risk for patients as well as a greater ability to diagnose and treat.

Looking for medical imaging in Louisiana? At Doctors Imaging, we’re Radiologists concerned with patient care. Meet our Radiologists or request your next medical impaging appointment online.

Diagnosing Emphysema and COPD with Medical Imaging

Emphysema is just one of several conditions under the umbrella term “chronic obstructive pulmonary disease.” COPD is a condition that causes the lungs to have difficulty taking in air. COPD includes conditions like emphysema, chronic bronchitis, refractory asthma, and some forms of bronchiectasis. Emphysema is the deadliest of the conditions and we will explore the symptoms and the diagnosis process. In Louisiana alone, more than 7% of the population is affected by COPD.
Source: COPD Foundation (PDF).

Symptoms of Emphysema and COPD

Many patients may have the disease but be unaware of it. Here’s a look at signs you may have the emphysema or COPD:

  • The earliest symptom of emphysema is shortness of breath. Even the slightest activities may tire you out.
  • Wheezing
  • A cough that won’t go away
  • Chest tightness or chest pain

How Doctors Identify Emphysema

What does emphysema look like? To begin, the interior of the lungs are filled with small air sacs called alveoli. These air sacs expand with oxygen when you breathe in and allow oxygen to get into the bloodstream. Emphysema is a condition that causes these air sacs to weaken and ultimately rupture. When they rupture, there is less area for oxygen to be taken in and since emphysema is a chronic condition, these alveoli will continue to weaken and rupture until the lungs are not able to expand and contract on their own.

Emphysema is most notably a result of cigarette or tobacco smoking. The chemicals found in cigarette smoke can total over 7,000 and they are extremely toxic to the entirety of the body, but the lungs take most of the damage. Upon inhalation, the hot smoke and toxic chemicals damage the lung tissue and with an addictive habit like cigarettes, the damage happens multiple times a day for years. With every puff, more lung tissue dies and once it is dead, there is no replacing it. In fact, about 85 to 90 percent of all COPD cases are caused by cigarette smoking in the United States.

If you are a long-term smoker or a former smoker and are over the age of 50, your chances for developing emphysema are much higher. The signs of COPD or emphysema can be confused with other conditions because things like shortness of breath or difficulty catching breath could be misconstrued as part of the aging process or the result of lifestyle choices. You see, as the air sacs are slowly destroyed, air becomes trapped in the lungs and is difficult to expel as well as obtain. Furthermore, if you are experiencing a tightness in the chest that does not seem to pass, these could be the beginning warning signs of COPD and possibly emphysema.

Diagnosing emphysema requires a few different tests. To begin, the doctor will use a physical examination to test things like your vitals and blood pressure. Following a physical, doctors will usually perform a combination of pulmonary function tests to examine the strength and performance of the lungs. Pulmonary function tests include breathing into tubes that can test how much air you are expelling, how fast it is being expelled, and how much air remains after exhalation.

Chest X-Rays and CT Scans

If the results of the pulmonary function test prove conclusive toward symptoms of COPD, doctors will use medical imaging to confirm the diagnosis. A chest x-ray is often performed to see if the lungs have become enlarged because of excess air or if there are structural changes in the lungs. However, diagnosing emphysema cannot be done with a chest x-ray alone. Chest CT scans are also used to diagnose COPD because they can show pockets of air in the lungs which are symptomatic of damage from COPD. All of these procedures are completely painless and require no invasive surgery and yet still provide accurate details and diagnosis.

At Doctors Imaging, we assist doctors in the diagnosis, treatment, and aftercare of sick or injured patients. Our staff offers state of the art medical technology along with decades of professional experience. We have been facing the concerning statistics of lung cancer and lung-related ailments in Louisiana for many years. But we know the importance of lung cancer screenings. We even offer a $99 lung cancer screening for long-time smokers and ex-smokers. Lung cancer screenings are available to each patient annually.

Want to learn more? Find out what to expect during a CT Scan. Ready to make an appointment? You can Request an Appointment online or call Doctors Imaging’s office in Metairie at 504-833-8111 Monday through Friday to speak to a representative.

A Look at Doctors Imaging’s Medical Equipment

At Doctors Imaging, we like to provide the best service, staff, and equipment along with the best price for our patients. We believe that everyone should have access to these machines so that they can be confident in their treatment plans and knowledgeable about their health conditions.

We have a 3T MRI and we offer an open MRI for the patients that feel uncomfortable or claustrophobic in the traditional MRI. A 3T MRI is the most powerful MRI machine for every part of the body and we are the region’s first freestanding center to offer its capabilities. There are other facilities and hospitals that use the 1.5T MRIs, but at Doctors Imaging, we want the most powerful equipment and since insurance companies usually charge the same price no matter what the equipment is, you can have the best equipment and images for a lower price than you would pay at a hospital.

In addition to our MRI machines, we also offer the low-dose CT machine, a powerful CT machine with the lowest radiation settings possible. We use the Toshiba Lightning Aquillon CT scanner with Adaptive Iterative Dose Reduction 3D software. With this technology, multiple “slices” or pictures of the examined area can be provided to doctors allowing them to see further and deeper into the body so they can give a thorough diagnosis and treatment plan. This machine allows for up to 75% reduction rate in radiation as opposed to many other CT machines on the market. We understand that radiation exposure is a concern for many of our patients which is why we dedicate ourselves to providing the best and safest care possible.

At Doctors Imaging, we also provide digital X-rays so there is less radiation exposure from this as opposed to the traditional X-ray machines. We also offer 3D ultrasounds so that expectant mothers, as well as medical patients, can have the most in-depth and detailed images of their babies and bodies available to them.

We want people to know that if you need a medical imaging procedure, you are not required to go to a hospital. Instead, you can come to Doctors Imaging in Metairie and have an immediate appointment, almost no waiting time, fast results and a great affordable price.

Visit our Make an Appointment page or call 504-883-8111 for the best days and times for your imaging procedure.  

How Often Should Ex-Smokers Get Lung Cancer Screenings?

A low-dose CT scan of the chest is a good way to detect multiple diseases and disorders, including chronic respiratory diseases and lung cancer.  Early detection of these diseases and disorders is essential to the successful fight against them.  The earlier they are detected, the better chance a patient has at survival.

This brings up a question, though.  If preventative screening is key to catching these diseases early, how often should one get tested?  Let’s take a look at today at one case in particular: a 55-year old ex-smoker who recently stopped smoking.

Our ex-smoker is 55 years old, and has had a history of smoking.  The patient has since stopped. The patient shows lung cancer symptoms now but is worried about an increased chance of developing lung cancer or some other respiratory condition in the future.

Where Public Health Organizations Agree

In August of 2011, the results of the National Lung Screening Trial (NLST) found that screening with low-dose spiral computed tomography (LDCT) scans compared to chest X-ray reduced lung cancer deaths among older heavy smokers by 20%, according to the American Lung Association.

As of December 2013, the U.S. Preventive Services Task Force began recommending “annual screening for lung cancer with low-dose computed tomography (LDCT) in adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery.” Further, the USPSTF “concludes with moderate certainty that annual screening for lung cancer with LDCT is of moderate net benefit in asymptomatic persons who are at high risk for lung cancer based on age, total cumulative exposure to tobacco smoke, and years since quitting smoking.”

The American Lung Association is on the same page: Our patient should get tested if they are a current or former smoker aged 55 to 74 years old, has had a history of smoking for at least 30 packs per year and has no history of lung cancer.

Now, if our patient gets tested and the results come back with no signs of lung cancer, are they off the hook for future testing?

No. The patient should still be tested annually.

The goal here is prevention, and the best way to do this is through screening, according to the American Cancer Society. Our patient is likely to develop lung cancer, so preventative screening is the best way to keep them healthy and perhaps save a life.

If you’re looking for preventative screening services (such as a CT scan), come to Doctors Imaging. We’re radiologists concerned about quality patient care. Scheduling is easy, results are available online, our rates are below hospitals, and we accept every major insurance.

Lung Cancer Symptoms and Screenings

Lung cancer is one of the most aggressive and commonplace cancers in the world. More people die from lung cancer than any kind of cancer and over 218,000 new cases are reported every year, according to the Centers for Disease Control and Prevention. The cancer is fast-moving. Without catching it in the early stages, survival chances decrease rapidly. That is why it is of the utmost importance for most smokers over the age of 55 to be screened with a CT scan for lung cancer.

The commonly reported lung cancer symptoms are:

  • a cough that doesn’t seem to go away
  • coughing up blood or bloody phlegm
  • severe, constant chest pain
  • shortness of breath or breathing issues

These issues can be easily confused with a severe cold or sickness. That may be part of the reason why people do not get properly screened. So if you notice any of these symptoms, be sure to contact your physician about getting a low-dose CT scan to check for cancerous nodules or masses in the lungs.

Another reason that lung cancer screenings are not occurring with enough frequency is that current smokers may be hesitant to admit their habit in a doctor’s office or hospital setting. Cigarette smoking is still the #1 cause of lung cancer in America. And smokers are aware of the health risks (they are written right on the package of cigarettes) but they are addicted to the nicotine.

While tobacco itself is a dangerous plant, it is the additives in cigarettes that contribute to the developing of lung cancer. Dangerous substances from cigarette smoking include all kinds of chemicals like nicotine, tar, carbon monoxide, ammonia, formaldehyde, cyanide, and arsenic. These chemicals are kept at low amounts. So they don’t kill customers quickly, but smokers die more slowly from diseases such as emphysema and lung cancer, all the while making smokers lifelong customers.

At Doctors Imaging, we don’t want shame and fear of results to keep patients from getting lung cancer screenings. Because of our equipment, experience, and other qualifications, we have been able to offer our services and help detect lung cancer and get our patients the treatment necessary.

Find out if you may qualify for a low-dose CT scan. Even if you’re not eligible for a free exam based on your age or other qualifications, we’ll make sure you pay no more than $99 out of pocket. You can even request your appointment online. The sooner you get your exam, the sooner you can take the next step toward a healthier life.

High-Resolution CT Scans Fit for a King and You Too

How CT Scans Produce Cross-Sectional Images

CT scans, or computed tomography, use computer technology along with X-ray capabilities to photograph the internal organs. CT imaging produces cross-sectional images of the organs so that doctors do not just see a flat picture, they see slices of the examined area. With CT scans, doctors can see through, into and around different body parts without the impediment of things like bones and muscles. This allows for a high level of detail and accuracy when looking at a patient’s body and finding the cause of disease.

CTs work to take “slices” of the body’s interior, meaning that if there is a spot or area to be examined, the machine takes several images of the same part but from multiple angles, ensuring that nothing is missed. These images are able to uncover what cannot be seen by the naked eye. And for patients that need CTs, they are the best way to get critical medical information without making any incisions. Because of the low dosage of radiation used in CTs, children and senior citizens can experience the benefits and advantages that CTs offer.

How Historians Used CT Scans to Examine King Richard III

CT scans have been a tool for diagnostic medicine for several decades. As medical technology and research become more advanced, this tool has been found in places other than hospitals, including places like laboratories and history books. By using the power of CT machines, numerous educational institutions are able to use CT technology to decipher and explain the mysteries of the past.

Understanding CT scans is a key skill for historians that specialize in discovering anything that has been dead and buried for centuries. For many archeologists and scholars, CTs can provide answers that no other method of academia can. They can even act as a forensic tool in solving centuries-old mysteries. A recent example of this is from 2012 when British scholars found the skeleton of King Richard III, a man who died over 500 years ago. While the stories and portrayal of King Richard III may be varied and less than perfect, what cannot be denied is how he died, thanks to understanding CT scans.

For many centuries, the skeleton of King Richard III was misplaced, a highly unusual fact for a person of royalty. In 2012, a group of scholars matched a map of the Battle of Bosworth Field and found what they believed to be the King’s skeleton underneath a parking lot in central London. However amazing their discovery might have been, without concrete forensic evidence, there would be no way to prove that this was the skeleton of a former English ruler.

Different accounts of Richard III remark at his physical appearance, most notably, a hunchback. The unearthed skeleton contained a spine curvature. Combined with the location of the skeleton, those who found him were positive that it was the former king. Historians were able to test the DNA of surviving relatives of Richard III to find out more about his appearance and answer the question as to how he died. By understanding CT scans and examining the skull, they were able to determine two specific blows to the head as well as another 11 harmful injuries on the body that likely contributed to his death, historians were able to discover all those facts about a 500-year-old skeleton.

If you have other questions about what CTs can see and do, check out the CT Scan Service Page or call 504-883-8111 and speak to a representative.

A $99 Lung Cancer Screening Could Save Your Life

Are you a longtime smoker, or a former heavy smoker? If you answered yes to either of these questions, you can reduce your risk of death from lung cancer by 20% when you receive a low-dose CT scan.

we offer lung cancer CT scans for as low as $99

This groundbreaking discovery in cancer prevention and treatment came in 2011 when the New England Journal of Medicine published a study supporting the value of CT scans in detecting lung cancer more effectively than traditional X-rays. Since the initial 2011 publication, radiologists and other health professionals have been working tirelessly to educate patients about the benefits of CT scans, while also trying to ensure that the procedure is as affordable and convenient as possible. Since 2011, more support has emerged in support of low-dose CT scans for this screening:

All these developments should simply highlight the life-saving value of this lung cancer screening.

And that’s where Doctors Imaging comes in. We don’t operate like a hospital or traditional imaging center. For us, the patient always comes first. So we are offering lung cancer CT scans for as low as $99 — a price you won’t find anywhere else in the Greater New Orleans area. In many cases, our CT scans are half the cost of a standard X-ray at the hospital.

Patients may be interested to know that the test takes about 10 minutes, and does not require needles or medicine.

When you’re ready, you can schedule an appointment online or just call 504-883-8111 to speak with a live representative. But don’t wait too long. Imaging services like low-dose CT scans can save your life if we catch lung cancer early enough.

More States in Need of LDCT Screening Centers

As opposed to cancers like leukemia and prostate, lung cancer is most often caused by lifestyle choices such as smoking cigarettes, other tobacco products or working in areas where carcinogen-filled smoke is present.

There has been an increase in advertising and lobbying for anti-tobacco campaigns. In addition, there are more than a few organizations now attempting to stop potential smokers in their youth before they pick up the habit. Thanks to these efforts and increased study on the connection between smoking and lung cancer, the rates of lung cancer in the U.S. have decreased considerably.

In hopes of combating the lung cancer statistics, the American College of Radiology and the American Cancer Society have teamed up to offer certification and accreditation to different facilities around the country that have met the strict informative, functional, and practicing ways that contribute to increased knowledge and prevention of lung cancer.

This initiative makes states more competitive in their efforts toward eradicating lung cancer, especially in states where there are high numbers of diagnosis. Medical imaging communities have done studies on the effectiveness of these centers throughout the country by first surveying how many are currently in operation. The survey showed that “nationwide, each state, including Washington DC, had a mean of four screening centers; however, 11 states had no screening centers identified. There was an average of 0.3 screening centers per 100,000 people aged 55 to 79. Among the states with the best capacity of LDCT screening centers were Washington, DC, Connecticut, Virginia, Colorado, and Maryland.”

The areas that need improvement are states like Mississippi, Arkansas, Oklahoma, Louisiana, West Virginia, and Missouri because they have some of the highest prevalence of lung cancer. Fortunately for New Orleans area residents, Doctors Imaging now offers the screenings.

Low-Dose CTs have been shown to be one of the best measures taken in early diagnosis of lung cancer. Because of the aggressive nature of lung cancer and the rarity of lung transplants, the earlier lung cancer is diagnosed, the sooner treatment can begin and the better the chances of survival are. CT scans (computed tomography) use X-ray capabilities to examine the internal structures of the body. CTs are the preferred imaging tool when searching for the presence of lung cancer. Lungs are made up of tissues, blood vessels, and nerves. Because CT imaging can produce cross-sectional images of the body’s tissue, CTs can see through bone and see the lungs from several angles, reassuring the patient that their scan is thorough.

Some may be hesitant to book an appointment for a lung cancer screening because they are worried about pain from the procedure or the possibility of radiation exposure. Please know that CT scans are completely non-invasive and the average procedure takes no more than 30 minutes. The CT machines are calibrated so that the radiation used to highlight the internal organs is an extremely low dose, about as much natural radiation a person experiences during a year. Even more beneficial is that your results will be ready and shared with your practicing physician on the same day. Please keep in mind that your doctor may need sufficient time to review the results of your exam.

If you believe that you have a possibility of developing lung cancer or you are a former or current smoker over the age of 50, please consider coming to Doctors Imaging for a lung cancer screening test. Our machines are state-of-the-art. And our friendly and experienced staff will help you with your imaging questions and concerns. Please review our CT Scan Page to learn preparations and common questions or call our offices at 504-883-8111.

Lung Cancer Detection in Louisiana Made Easy

Lung cancer is a devastating condition to suffer. There are as many as 228,000 new cases of lung cancer to be diagnosed in 2019 and as almost 142,000 people will die from lung cancer-related complications. This translates to about 1 in 15 men and 1 in 17 women will be likely to develop lung cancer. You can see that lung cancer statistics in the United States are alarming, which is why Louisiana doctors are committed to finding innovative ways and techniques to both detect and treat lung cancer.

As a patient, the symptoms of lung and or bronchi cancer can be difficult to see at first. Symptoms of lung cancer could be can be innocuous things like a cough that won’t seem to go away, chest pain with deep breathing or coughing, shortness of breath, feeling tired and weak or hoarseness in the voice. As you can see from this symptom list, these symptoms could be a bad chest cold. That is why lung cancer diagnoses are made when cancer has become serious or terminal because people are not trained to recognize the signs.

Like most cancers, there can be one reason or several reasons why someone develops cancer. Cigarette or tobacco smoking is the most common cause of lung cancer. The Center for Disease Control has named smoking as “the number one risk factor for lung cancer” linking the habit to 80-90% of lung cancer diagnoses. Even if you are not a smoker, working or living around secondhand smoke can lead to lung cancer. Cigarette smoke is loaded with carcinogens and other toxic chemicals like tar, nicotine and carbon monoxide that can develop into lung cancer without ever even smoking a cigarette. Other risk factors for lung cancer include radon exposure, a naturally occurring gas that can be trapped in homes and buildings, that rises from the ground. You can have your home or office tested for radon levels and the EPA has a set of guidelines for lowering the radon levels in your dwelling. Other risk factors for lung cancer include family history or genetic issues as well as exposure to toxic substances like asbestos and chromium.

Louisiana is one state in particular that has a high instance of lung cancer. 68 per 100,000 residents have lung cancer and 51 per 100,000 die every year from the condition in Louisiana alone. With statistics like this, it is lucky that lung cancer detection in Louisiana has been made easier and more advanced with the help of local facilities like Doctors Imaging.

If you think that you may have lung cancer or would like to set up an appointment to discuss preventative measures, please contact Doctors Imaging in Metairie at 504-883-8111 Monday through Friday from 8:30 AM to 5 PM.