Showing posts with label Technology. Show all posts
Showing posts with label Technology. Show all posts

1/16/11

MRI Scans vs CT Scans

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There a few different methods of obtaining medical diagnostic images. Each method or type is known as a modality. In particular, MRI scans and CT scans bring a great deal to the field of medicine. Doctors use both modalities to help them provide accurate information about their patient in order to accurately diagnose what is wrong with them. There are differences between the two, with each providing its own advantages and disadvantages. This article acts as a guide to explaining the main differences between these two important and effective types of scan. Read on to find out more. 

The acronym CT, used with in the term CT scan, is an abbreviation of computed tomography. This modality uses x-rays which is a type of ionizing radiation to produce images of the body's interior. This makes it particularly good at investigating tissue that is more dense than the tissue that surrounds it. A good example of this is bone compared to muscle and the soft tissue and cells encasing it. In order to gain more clarity when using a CT scan, the medical personnel may administer what is known as a contrast agent. To get the most from this, the substance used may be more dense than the part of the body being investigated. This makes iodine or barium good substances to use. For example, for those of us who have had x-rays, the term barium meal may be familiar. 

The acronym MRI is an abbreviation of the term magnetic resonance imaging. Unlike CT and x-ray systems, MRI does not use ionizing radiation. Instead it uses radio waves sent through a magnetic field to acquire its images. This makes it ideal for investigating non-calcified tissue, i.e. other than bones and teeth. That is not to say it cannot be used for this purpose, it is just better suited for looking at softer tissue, organs and cells in the body. A contrast agent can also be used when carrying out an MRI scan: gadolinium or manganese are the most appropriate types as they have paramagnetic properties, and of course MRI makes use of magnetic fields. 

Although both CT and MRI scans produce two dimensional images of tissue and three dimensional reconstructions are created from this, MRI scans have greater image contrast capabilities. By varying an array of scanning parameters, different features of the body can be detected more easily. An MRI is generally considered to be more accurate when it comes to detecting tumors or problems in the brain, although a CT scan is better at detecting solid tumors in the abdomen or chest. 

A CT scan is cheaper than carrying out an MRI scan and is also more widely available so is usually the preferred route to take by doctors. An MRI scan tends to be used only when they have exhausted the other options and need further information still. A CT scan is also much quicker than an MRI scan. 

Both MRI scans and CT scans are important tools used by a doctor to facilitate accurate diagnoses of serious illnesses such as heart disease and cancer. When used in imaging in oncology, these modalities are particularly vital. By combining scanned images over time they allow information to be obtained such as how much the cancerous cells have spread and at what rate they are growing. This means patients can receive updates on whether their treatment is working and whether the cancer shrinking rather than growing in size. PET CT software in particular is vital for providing valuable oncological information such as this. Very different but equally as important as one another, CT scans, and MRI scans as well, play an important role in modern medicine.

1/9/11

Coronary Computed Tomography Angiography: General Considerations

Coronary computed tomography (CCTA) is currently considered to be a technique for high-resolution computed tomography (CT) imaging of the heart. It has become generally accepted that patients with negative CT cardiac results will not need to undergo cardiac catheterization. The radiation dose for the CCTA with modern techniques is much lower than even a few years ago and in some cases, even lower than for cardiac catheterization.

The 64-Slice CT scanner is considered to be the high-end CT system and is preferable for CCTA. However, even earlier generation CT systems are suitable for this task.

In some research studies, there has been an attempt to determine the most beneficial use of cardiac CT scanners, and the consensus appears to be that the high negative predictive value of the multislice CT scanner, used to filter out those patients who do not require further investigatory tests for coronary disease, is where it is currently used most effectively.

CCTA is a non-invasive test, requiring only a contrast injection and for some patients, beta blockers. Therefore the CT scan can be performed as an outpatient examination. The disadvantage of CCTA is that there is a limitation with respect to the image quality for patients with irregular or high heart rates. In such cases, patients may be medicated by beta blockers.
CCTA is also limited where there is extensive calcification, as the high contrast of the calcium leads to "blooming" artifact.

The implementation of X- ray tube current modulation resulted in a dramatic decrease in radiation. In addition, the use of CT scans with ECG -triggering of the radiation resulted in average doses around 3 MSV.

The cost of premium-class, 64-slice CT scanning can be $1.2 - $1.5 million. A dual-source, 64-slice CT scan system costs $1.9 - $2.5 million.
The running costs including: a service contract, three full- time staff members and contrast media are $700 - $850k. In terms of potential revenue, the CCTA exam costs about 10% to 12% of the cost of cardiac catheterization.

Technical Considerations

CCTA requires an accurate imaging of coronary arteries, which move with the cardiac and respiratory cycles. Therefore, high spatial resolution and high temporal resolution are essential.

High contrast-to-noise ratio is of primary importance. To achieve a good enough ratio, it is possible to either increase the X-ray tube output and use thicker slices, or to increase the contrast. The spatial resolution will be impaired by increasing the slice width and filtering the signals.

To eliminate cardiac motion artifact, high-rotation speed system is necessary. Current cardiac CT scanners have 3-3.3 R.P.M speed.

For higher temporal resolution, half the gantry rotation time is used for the reconstruction. To assure the best temporal resolution, it is important to acquire the image in the most stationary phase of the cardiac cycle. Therefore, ECG signal is used to enable the reconstruction of the CCTA image in the cardiac phase of least motion.

The typical scan length of a CCTA examination is about 14 CM. It is essential that the CT scan is completed well within a patient's breathhold, so as to avoid respiratory motion artifacts.

Imaging of the coronary arteries can be achieved on a CT scanner in a variety of different ways. Where the complete heart cycle is scanned, greatest flexibility is available in selecting the optimal phase for coronary artery image reconstruction. This approach enables the best functional analysis. However, the dose to the patient is high. Where only a selected part of the cardiac cycle is CT scanned, the radiation is only during a short interval. In this situation, the radiation is low. There is also the merging of the two approaches: all phases of the heart are CT scanned with reduced radiation, and only the stationary phase window is fully illuminated. Full image quality is obtained for the coronary artery image required phase, whereas the images for functional analysis have lower quality.

In general, the CCTA systems can be classified in 4 groups:

1. Axial scan, Prospective ECG Triggered: this is the most commonly used mode, due to the resultant lower dose. Modern systems typically require 3-4 rotations. It is suitable for patients with heart rates below 70 BMP.

2. Axial scan, Retrospective ECG Gated: in this mode, the axial scan is performed over the full cardiac cycle, over a number of gantry rotations (depending on the detector coverage) so the patient is exposed to high-dose rates.

3. Helical Scan, Retrospective ECG Gated: in this mode the radiation is continuous, while the heart is covered with a low-pitch helical scan. The involved radiation dose is high. This is the mode of choice for patients with high or unstable heart rates.

4. Helical scan, Prospective ECG Triggered: in this mode, the radiation is triggered by ECG, as it is with the axial triggered systems. Systems with dual source (two x-rays tubes and detectors which are positioned at 90 degrees each to other) can be operated at high pitch. A full scan can be performed in less than 0.5 seconds.

Low-pitch prospective systems are rare nowadays.

Performance of CCTA
CT scanning results in a plain-scan resolution of approximately 0.5 mm. With a typical reconstruction field of view of 25 cm, and a reconstruction matrix of 512×512, the pixel size is approximately 0.5 mm, which is a good match for the resolution.

The longitudinal axis resolution of modern, quality CT scanner systems approaches 0.5 mm.

1/8/11

The gift of technology, all year long - Dental Economics

Terry L. Myers, DDS, FAGD

For more on this topic, go to and search using the following key words: dental technology, digital imaging, digital radiography, digital X-rays, 3-D imaging, cone beam, technology, social media, e-mail, Dr. Terry L. Myers.

December is filled with holiday activities, some sentimental "Auld Lang Syne," and anticipation of new adventures. With the improving economy, hopefully the stores will be filled with shoppers looking for perfect gifts. During this season, don't forget to put your practice on your shopping list, and give yourself a "gift that keeps on giving." This phrase was originally used for a phonograph ad in the 1920s, but its spirit still has voice today – the gift of technology will continue to benefit your practice long after the holiday season.

My favorite technologies bring cheer to my office year-round.


Digital radiography has many attributes for the dentist, the patient, and the staff. Digital imaging, especially with my DEXIS® Platinum sensor, provides clear, crisp images that can show cracks, periapical radiolucencies, and even interproximal decay that has broken through the enamel to the dentin.

I can enlarge the image to fill my large computer monitor while maintaining resolution. For me, that's the gift of better treatment planning. There's no waiting for all of this either; digital images appear on the screen almost immediately.

My patients receive the gift of understanding that ultimately leads to their increased and continued dental health. With the clarity and size of the image, educating my patients is much easier, and I can draw or spotlight areas of interest. My sensor's rounded corners increase patient comfort, and that's a cause for celebration too.

My staff gladly accepts the gift of an easier workday. With the direct USB connection, they can easily transport the sensor between operatories and plug in without a docking station. The cable and shape of the digital sensor allows for quicker, easier movement around the mouth, reducing an FMX to a five-minute job.

Not cleaning up or changing the chemicals involved in traditional X-ray is not only a gift, it is a relief. Images can be integrated into a practice-management system, such as DENTRIX, so that all patient files, history, and images are organized and easily retrieved.

For expanding the scope of my practice, my medium-field-of-view GXCB-500 HD™ cone beam scanner gives me the gift of information that is unavailable in 2-D formats. This radiographic option is perfect for diagnosis and patient education for more complicated procedures, such as implants.

From the CBCT scan, I can determine the height and width of bone, position of the roots, and proximity of the teeth to the nerves and sinuses. Now, I can keep more patients in-house, whenever possible, and plan less-invasive procedures.

Intraoral cameras also help with case acceptance. These views provide a great perspective of deteriorating amalgams, possible crown opportunities, tooth fractures, periodontal problems, or even small cracks.Intraoral and extraoral pictures can be printed or e-mailed to patients so they don't forget why treatment is necessary.

As communicating with existing patients and reaching new ones becomes more tied to the Internet, visual technology, such as social networking and Web design, take center stage. Make an impact by emphasizing your technological capabilities on your Web site, Facebook page, or Twitter feed.

Reminders through cell phone texting or e-mails keep the younger generation on time for appointments, and birthday messages remind everyone that their teeth need a birthday checkup too.

I hope this year of columns has given you additional insights into incorporating innovative dental economics and growing a successful business, as well as providing the best care possible to patients. All of us at Keystone Dentistry wish you happiness, health, and technology that counts, all year long!

Dr. Terry L. Myers is a fellow in the Academy of General Dentistry and a member of the Academy of Cosmetic Dentistry and the Dental Sleep Disorder Society. He has a private practice in Belton, Mo. You may contact Dr. Myers at office@keystone-dentistry.com.Digital technology: an ongoing gift for you and your patients

More DE Articles
Past DE Issues

View the original article here

1/6/11

The gift of technology, all year long - Dental Economics

Terry L. Myers, DDS, FAGD


For more on this topic, go to and search using the following key words: dental technology, digital imaging, digital radiography, digital X-rays, 3-D imaging, cone beam, technology, social media, e-mail, Dr. Terry L. Myers.


December is filled with holiday activities, some sentimental "Auld Lang Syne," and anticipation of new adventures. With the improving economy, hopefully the stores will be filled with shoppers looking for perfect gifts. During this season, don't forget to put your practice on your shopping list, and give yourself a "gift that keeps on giving." This phrase was originally used for a phonograph ad in the 1920s, but its spirit still has voice today – the gift of technology will continue to benefit your practice long after the holiday season.


My favorite technologies bring cheer to my office year-round.


Digital technology: an ongoing gift for you and your patients


Digital radiography has many attributes for the dentist, the patient, and the staff. Digital imaging, especially with my DEXIS® Platinum sensor, provides clear, crisp images that can show cracks, periapical radiolucencies, and even interproximal decay that has broken through the enamel to the dentin.


I can enlarge the image to fill my large computer monitor while maintaining resolution. For me, that's the gift of better treatment planning. There's no waiting for all of this either; digital images appear on the screen almost immediately.


My patients receive the gift of understanding that ultimately leads to their increased and continued dental health. With the clarity and size of the image, educating my patients is much easier, and I can draw or spotlight areas of interest. My sensor's rounded corners increase patient comfort, and that's a cause for celebration too.


My staff gladly accepts the gift of an easier workday. With the direct USB connection, they can easily transport the sensor between operatories and plug in without a docking station. The cable and shape of the digital sensor allows for quicker, easier movement around the mouth, reducing an FMX to a five-minute job.


Not cleaning up or changing the chemicals involved in traditional X-ray is not only a gift, it is a relief. Images can be integrated into a practice-management system, such as DENTRIX, so that all patient files, history, and images are organized and easily retrieved.


For expanding the scope of my practice, my medium-field-of-view GXCB-500 HD™ cone beam scanner gives me the gift of information that is unavailable in 2-D formats. This radiographic option is perfect for diagnosis and patient education for more complicated procedures, such as implants.


From the CBCT scan, I can determine the height and width of bone, position of the roots, and proximity of the teeth to the nerves and sinuses. Now, I can keep more patients in-house, whenever possible, and plan less-invasive procedures.


Intraoral cameras also help with case acceptance. These views provide a great perspective of deteriorating amalgams, possible crown opportunities, tooth fractures, periodontal problems, or even small cracks.Intraoral and extraoral pictures can be printed or e-mailed to patients so they don't forget why treatment is necessary.


As communicating with existing patients and reaching new ones becomes more tied to the Internet, visual technology, such as social networking and Web design, take center stage. Make an impact by emphasizing your technological capabilities on your Web site, Facebook page, or Twitter feed.


Reminders through cell phone texting or e-mails keep the younger generation on time for appointments, and birthday messages remind everyone that their teeth need a birthday checkup too.


I hope this year of columns has given you additional insights into incorporating innovative dental economics and growing a successful business, as well as providing the best care possible to patients. All of us at Keystone Dentistry wish you happiness, health, and technology that counts, all year long!


Dr. Terry L. Myers is a fellow in the Academy of General Dentistry and a member of the Academy of Cosmetic Dentistry and the Dental Sleep Disorder Society. He has a private practice in Belton, Mo. You may contact Dr. Myers at office@keystone-dentistry.com.Digital technology: an ongoing gift for you and your patients

More DE Articles
Past DE Issues

View the original article here

NinePoint Medical Adds Optical Coherence Tomography Technology Expert to Board ... - Business Wire (press release)

Eric Swanson Brings More than 30 Years of Technical and Operational Experience to Company

CAMBRIDGE, Mass.--(BUSINESS WIRE)--NinePoint Medical, an emerging leader in the development of in vivo pathology medical devices, today announced the appointment of Eric Swanson as a new member of its board of directors, effective immediately. Mr. Swanson’s appointment expands NinePoint Medical’s board of directors to four members. Mr. Swanson is currently a research affiliate at the Massachusetts Institute of Technology (MIT), a consultant for Draper Laboratory, and an advisor to high-tech startup companies covering a wide range of technologies, including biomedical imaging and optical components.


“Eric is widely considered to be a thought leader within the field of optical coherence tomography and telecommunications, and we believe his broad range of experience and expertise will meaningfully expand our board’s capabilities”

“Eric is widely considered to be a thought leader within the field of optical coherence tomography and telecommunications, and we believe his broad range of experience and expertise will meaningfully expand our board’s capabilities,” said Charles Carignan, president, chief executive officer and board member of NinePoint Medical. “As NinePoint continues to develop a suite of optical imaging devices focused on the convergence of the access, diagnosis and treatment paradigm for the GI tract, Eric’s extensive business experience, contacts and technical know-how will bring a unique and relevant perspective to NinePoint Medical. We are pleased to welcome Eric to our team and look forward to his many contributions.”

"I am excited to join NinePoint Medical’s board and continue to build on my experience working with startups composed of great people, great technology, great market opportunities and, most importantly, the potential to make a major impact. NinePoint Medical is at an exciting stage, and its technology platform has the potential to greatly improve the diagnostic and treatment options available to the medical community,” said Mr. Swanson. “I look forward to working closely with the rest of the board and management team to move NinePoint’s innovative technology forward in development.”

Prior to his current roles as advisor and consultant, Mr. Swanson was the chief scientist at Sycamore Networks, which he co-founded. The company develops and markets intelligent optical switches and other products designed to create more effective communications networks and executed a successful NASDAQ initial public offering in 1999 that reached more than $14 billion in market capitalization at the end of its first day of trading. Before founding Sycamore, Mr. Swanson co-founded and was the chief technology officer of LightLab Imaging, a biomedical imaging company that commercialized OCT for a wide range of medical markets including cardiology and endoscopy. Lightlab was ultimately acquired in 2010 by St. Jude Medical for $100 million. Prior to LightLab Imaging, Mr. Swanson co-founded Advanced Ophthalmic Devices (AOD), a startup focused on ophthalmologic imaging using OCT. AOD was acquired in 1994 by Carl Zeiss Meditec, a leading ophthalmic instrumentation company, and served as a foundation for Zeiss’s highly successful world leading ophthalmic OCT product line. Prior to AOD, Mr. Swanson was an assistant group leader of research and development at the Lincoln Laboratory at the Massachusetts Institute of Technology for 15 years.

Mr. Swanson has authored more than 180 technical papers and holds more than 27 US patents and numerous foreign patents. He is a fellow of the OSA and senior member of the IEEE. In 1992 he received the prestigious Rank Prize for contributions to mankind in Opto-Electronics for his work in the field of OCT. Mr. Swanson holds a B.S. summa cum laude in electrical engineering from the University of Massachusetts at Amherst and an M.S. in electrical engineering from the Massachusetts Institute of Technology.

About NinePoint Medical, Inc.

NinePoint Medical, Inc. is a transformational medical device company developing innovative, real-time, in vivo pathology devices focused on dramatically improving patient care. Through its proprietary optical frequency domain imaging (OFDI), a next-generation frequency domain optical coherence tomography, NinePoint intends to bridge the gap between the diagnosis and treatment of disease. With its advanced optical technology, OFDI will enable physicians and pathologists, for the first time, to view real-time, high resolution imaging of entire organs. Initially, NinePoint is focusing on devices that enable real-time screening and surveillance of the gastrointestinal (GI) tract for patients with Barrett’s esophagus, one of the most common precursors to esophageal cancer. Eventually, NinePoint intends to develop medical devices that provide physicians with immediately actionable information and that will allow them to diagnose and treat patients during the same procedure. This convergence of access, diagnosis and treatment during one procedure is expected to improve patient experiences and outcomes, improve the efficiency of care and provide important savings to the healthcare system. Broader applications of NinePoint’s technology are expected to follow in a variety of areas including pulmonary medicine, gynecology, urology and ENT. Headquartered in Cambridge, Mass., NinePoint is backed by Third Rock Ventures and Prospect Venture Partners. For more information, please visit www.ninepointmedical.com. View the original article here