Better Imaging, including MRI, PET and 320-Slice CT, Creates Advances in Detection

Today, improved diagnostic imaging, diagnostic catheterization and better monitoring procedures have made earlier detection of many diseases possible and reduced the need for exploratory surgery. Over the long-term, highly advanced new imaging systems, eventually utilizing molecular diagnostics, will enable levels of early intervention undreamed of in the past.

Magnetic resonance imaging (MRI) uses a combination of radio waves and a strong magnetic field to gauge the behavior of hydrogen atoms in water molecules within the body. Improvements in hardware and software have made MRI scans faster and more thorough than before. Ultra-fast MRI has many important clinical applications. Recent studies show that MRI may be the best method for determining the extent of a patient’s recovery after a heart attack. Rapid-imaging MRI machines also expedite the diagnosis and treatment of heart conditions and strokes, thus reducing the time and money needed to scan the patient.

However, this technology has been extremely expensive, with equipment costs alone running from $1 million to $2 million. Until recently, very heavy shielding was needed to encapsulate the imaging room, which necessitated special construction of new facilities or very costly reinforcement of older building space. Progress in shielding technology and facility design, combined with more cost-effective mid-field and low-field MRI, has dramatically lowered the cost of most new installations. Some of these lighter, less powerful devices can be used in mobile settings, which makes MRI available in rural areas that could never have justified the expense of permanent installations. Low-field MRI technology has also enabled the development of open-MRI devices, which do not require a patient to be completely surrounded by a tunnel-shaped magnet. Open MRIs reduce patient anxiety and claustrophobia. In addition, the lower intensity of the magnetic field allows technicians, physicians and even family members to be present in the room at the time of the test, if the patient prefers.

Whole-body MRI can be useful for checking the entire skeleton or multiple parts of the body for metastasis of cancer. Although not part of routine patient care in the U.S., many health manufacturers such as Siemens, General Electric and Philips, are making scanners with full-body capability. The technology utilizes a gliding table that moves the patient smoothly enough to keep images clear. Related software takes five to six sets of images and weaves them together for a complete picture. The process generally takes about 20 to 45 minutes, the same amount of time used in traditional MRI.

Magnetoencephalography (MEG) is a newer technology derived from both MRI and electroencephalography (EEG). Like EEG, MEG registers brain patterns, but whereas EEG measures electrical activity in the brain, MEG measures magnetic waves, primarily in the cerebral cortex of the brain. Computer enhancement of the generated data is improving EEG as a diagnostic tool. Recent refinements in EEG technology make it possible to use this device to help diagnose various forms of depression and schizophrenia.

Computed tomography (also known as a CT scan or CAT scan) uses a circular pattern of x-rays to produce high-resolution, cross-sectional images, which can help precisely locate tumors, clots, narrowed arteries and aneurysms. Because CT essentially creates images of distinct slices of the body, it can be referred to as multi-slice or multi-row detector imaging. CT can produce three-dimensional images, which are beneficial in reconstructive surgery. However, CT machines cost between $1.5 million and $2 million or more for 64-slice technology. The advanced electronics enabling 64-slice CT (compared to 8- and 16-slice CT) are an immense breakthrough in the evolution of imaging. For example, 64-slice CT can show a higher level of detail in arteries than angiography, which is the traditional method of looking for arterial blockage and plaque when checking cardiovascular health. In fact, 64-slice CT enables the user to see cross-sections of arteries, including the walls. And, this advanced CT can provide vastly improved images of beating hearts, including the interior. (About 1.5 million U.S. patients undergo angiograms yearly. A CT scan does not bring the risk of arterial puncture associated with angiography’s wire-guided probes.) 64-slice CT is extremely useful for early detection of heart disease as a preventive measure, and for guiding surgeons during surgery.

There is some concern about the exposure of patients to radiation during CT scans. In response, General Electric Healthcare developed a device that reduces radiation during cardiac CT scans by up to 70%. The system is called SnapShot Pulse, and it pulses with a patient’s heartbeat, automatically turning the X-ray on and off at desired times during the heart rate cycle, which reduces the patient’s radiation exposure time.

The latest advance is the 320-slice CT (similar to but more powerful than recently-introduced 256-slice CTs), which has the ability to provide astonishing levels of image resolution. Both 256-slice and 320-slice CTs can scan areas as large as 6.3 inches, wide enough to capture almost all human organs. Each scan takes one second or less, compared to the 64-slice CT which takes up to 10 seconds for a scan of an area of 1.3 inches. In addition, the device measures subtle changes in blood flow or minute blockages forming in blood vessels in the heart and brain. The first 320-slice CT scanner in North America was installed at The Johns Hopkins Hospital in late 2007. There are 320-slice scanners installed around the world, including one in Chennai, India. A second-generation 320-detector row CT scanner requires less time and exposes patients to less radiation. Extremely fast scans will mean that large numbers of patients can be processed daily with one of these expensive machines. The cost of scans may drop proportionately.

As with MRIs, there has recently been some interest in whole-body CT scans. Many independent imaging centers have been offering such scans to the public at reasonable cost. However, there is concern among some physicians that whole-body CTs often lead to a large number of questionable findings, or false positives, and that such scans may be of little value.

Two other imaging machines, single photon emission computed tomography (SPECT) and positron emission tomography (PET), use forms of radioisotope imaging to detect and study conditions such as stroke, epilepsy, schizophrenia and Parkinson’s and Alzheimer’s diseases. PET is a major research tool for understanding the human brain, and has a substantial indirect impact on medical and surgical practices.

PET offers a unique advantage in that it can offer functional imaging. That is, it can show how an area of the body is functioning and responding. Because it is based on safe, short-lived radioactive substances that are injected into the body, PET enables physicians to see metabolic activity. For example, in addition to imaging of brain activity, PET can be used to determine how cancerous tumors react to certain drugs. The FDA is cooperating with the National Cancer Institute to determine whether PET should be used in clinical trials of new cancer treatments to determine whether tumors are responding to therapies.

Other improvements in x-ray technology include digital subtractive angiography (DSA). DSA involves the use of enhanced x-rays to see blood vessels and arteries, while bones and soft tissues are blotted out of the image. It can clearly image aneurysms and can be used in angioplasty, a procedure that reduces the need for heart bypass surgery. However, as advanced CT becomes more widely accepted, DSA may become irrelevant.

Mammography is another x-ray technology that has been refined over the years. While traditional mammography with film offers sufficient x-ray images of older women’s breasts, the film lacks the versatility of gray values that radiologists need to interpret mammograms from younger women. A new digital x-ray sensitive camera produces digital images on a computer screen with a higher dynamic range of gray values. Modern mammography equipment gives detailed and precise images of breast tissue, resulting in high detection levels of very small malignant tumors. The sooner a malignancy is discovered, the better the prognosis is for excision and follow-up treatment success. Advanced mammography techniques reduce the chance for misdiagnoses, the amount of radiation needed to develop the image and the time spent in the exam room.

Another improved imaging technique, sonography, uses ultrasound to create images of internal body tissues and fetuses. Ultrasound is a cheaper alternative to many other imaging techniques, and results are available almost immediately. This scanning technique is recommended for pregnant women, since the sound waves apparently cause no harm to human tissue. Refinements in sonography have led to excellent prenatal images, which can be used to detect even small abnormalities in a fetus. Sonography is also being used in other imaging applications. For example, a recent ultrasound device is capable of displaying a three-dimensional image of organs such as the heart. Ultrasound in real time has even become sensitive enough to show blood flow. Ultrasound units are common in all but the very smallest hospitals.

New ultrasound diagnostic devices are now on the market that are small enough to carry and provide doctors with a comprehensive picture of a patient’s major organs and possible problems. These devices, which resemble the handheld scanners used on Star Trek, use ultrasonic waves to map out the interior features of a patient and then enhance them to provide an accurate and easy-to-read picture. Not only can doctors spot heart murmurs and breathing abnormalities with a simple inspection, but they can also spot objects like kidney stones and gallstones, or the presence of an abnormal amount of fluid surrounding an organ. The machines could potentially save millions in radiology and other diagnostic bills. In addition, these devices will be carried on ambulances or even on a doctor’s person, allowing diagnostics to be performed wherever they are needed. The popular SonoSite M-Turbo is the size of a small laptop computer. A startup called the Butterfly Network (www.butterflynetinc.com) invested $100 million to develop a hand-held ultrasound scanner in which ultrasound emitters are etched directly onto a semiconductor chip. The compact, versatile unit, called Butterfly iQ, costs a few hundred dollars and delivers to create 3-D images in real time. It was introduced in the U.S. in 2018, and received licensing approval in the UK, Europe, Australia and New Zealand in 2019.

Ultrasound may take a giant leap forward with the advent of photoacoustic tomography, which combines sound waves with optics. Pulses of laser light are projected onto tissue which infinitesimally raises the tissue’s temperature. The rise in temperature causes the tissue to expand slightly, and in the process emitting sound waves in the ultrasonic range. Sensors on the patient’s skin pick up the waves which are analyzed and triangulated by computer. The resulting image may be as detailed as those derived by MRI or CT scans, but use equipment the size of an ultrasound scanner.

Another exciting monitoring technique involves measuring the levels of the chemical creatine in the heart, which indicate the extent of muscle damage caused by a heart attack. Using a combination of MRI and MRS (magnetic resonance spectroscopy), this noninvasive method allows doctors to pinpoint injured heart tissue by measuring depleted levels of creatine in areas of the heart that were difficult to view using older imaging techniques.

Some patients even carry monitoring equipment on or in their bodies for long-term diagnostic purposes relating to biochemical balances, brain and sleep disorders, heart and vascular diseases and metabolic problems. More accurate, easy-to-use equipment has been introduced. For example, Medtronic has released an implantable heart monitoring device the size of three sticks of gum. Released under the company’s Reveal brand, the device can detect brief heart stoppages or other abnormalities and report them to a support network.

Light diagnostic devices have also been showing up to diagnose certain forms of cancer. Similar to spectroscopy, which has been used to analyze chemical compositions for decades, these small diagnostic devices detect cancer by finding abnormalities in the body's reaction to light. In one instance, doctors at the University of Texas at Austin found that cervical cancer could be detected using a small ultraviolet light shown on the cervix. Precancerous cells are distinctly more fluorescent than normal cells. A preliminary study showed that the technique was 50% more accurate than a PAP smear and microscope examination, reducing the need to perform further diagnostic biopsies on healthy women. In another instance of light diagnostics, researchers at the University of California, Irvine found that infrared light could assist in finding breast cancer.

SPOTLIGHT: PSMA PET Scans

A breakthrough for prostate cancer patients is the Prostate-Specific Membrane Antigen (PSMA) scan in which patients are injected with a radioactive isotope called Gallium (Ga 68). The isotope quickly finds and clings to malignant cells which “light up” in PET scan images, making cancer detection possible before significant tumors develop. Even more exciting is the possibility in the future to bind radiation to the isotope, thereby killing malignant cells as they are detected. As of mid-2019, PSMA PET scans were in clinical trials in several U.S. locations and in Europe, Asia and Australia.

Internet Research Tip:

For descriptions of advanced imaging procedures, see the web site of the Radiological Society of North America at www.rsna.org.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Become a Plunkett Research Online subscriber to gain unlimited access to our massive amount of vital industry data and market research.

✔ 100,000 Industry Statistics
✔ 500 Industries Analyzed for Market Size, Profits and Forecasts
✔ 150,000 Industry Executives Profiled
✔ 25,000 Companies Profiled, Ranked and Analyzed
✔ 1,000 Vital Trends Analyzed, totaling 1,000,000 words

Learn More

Better Imaging, including MRI, PET and 320-Slice CT, Creates Advances in Detection, Business and Industry Trends Analysis

A Representative List of Organizations that Have Used our Research and Products:

How to access Plunkett Research data.

What data challenge can we help you solve today?

Take a Tour

Contact

Testimonials