Dental Imaging - What is happening there?

The first time I was started thinking about dental imaging from a different point of view was when I heard in a talk the speaker saying: "These are statistics about medical imaging, without dental imaging.". I wondered "Why are dental imaging statistics not included?"

My first thought was "well maybe they are seldom"... then again "why would the speaker referred to them specifically?". Dental imaging is definitely increasing! but it seems these procedures are not accounted for when talking about medical imaging. The main dental imaging procedure is X-ray imaging, because X-rays are great for imaging bones and teeth. The increase comes from the fact that digital imaging is now available, which facilitates handling of images. Also, the widespread of these imaging devices make them more prone to use. When I was young, I made some dental images before I wore braces. These images had to be done in a specific clinical imaging facility and were not performed at the dentist clinic. Now, most dental clinics have these devices. Some even say that you should do an annual check up using this technology, so don't be too surprised if the dentist ask you for this next time.

Should you do it? When is it recommended?
The advantage of doing such type of exam without any complaints, it is probably that you will find a cavity before it becomes painful...or to study the evolution of a problem. The disadvantage are the cost and of course, the dose. Although the small doses present in these exams, they are still there. I refer again to this webtool, where you can calculate on your own the risks: Xrayrisk  Traditionally, dental imaging present intra-oral 2D images, but extra-oral are also possible, including 3D images (tomography) which are obtained with a CT scan. Nevertheless, complex exams such as pan-tomography or tomography should only be done in case there is a problem, not for check up...

The main problem with dental imaging is the lack of regulation (either for prescription or safety) and the training of the human resources for these exams. In imaging clinics, you have human resources with radiography studies and possibly even a physicist. In dental clinical, which human resources do they have? 

For more information about the technology and challenges, this article is a good review:
Vandenberghe B, Jacobs R, & Bosmans H (2010). Modern dental imaging: a review of the current technology and clinical applications in dental practice. European radiology, 20 (11), 2637-55 PMID: 20544352

Microwave for breast imaging?

When we hear the word microwave, we immediately think about the heating device we have in our kitchen. But the word microwave just means waves with wavelengths from ranging from 1 meter to 1 millimeter (corresponding frequencies are 300MHz to 300 GHz). Microwave technology has been used in several engineering fields, and biomedical engineering is no exception. Microwave technology is used in the Radio Frequency components for MRI, but it also can be used as an imaging modality of its own. Microwave Imaging is research in progress, but there have been a number of groups working on this, which makes me believe that this will be available soon.

What are the principles behind Microwave Imaging?
Living tissues have different electrical properties than those of air. Therefore, the setup usually involves a liquid around the object and where the antenna is also immersed, so that the interface is minimized. When microwave radiation interacts with living tissue, microwaves can be transmitted, reflected or dissipated (by heat). The penetration of the microwaves goes until about 10 cm. The transmitting antenna emits microwaves and other antennas receive the transmitted and reflected waves. (The transmitting antenna can also receive.) There are differences in the properties of healthy tissue and malignant tumors. The tumors cause the waves to suffer scatter and the waves have now different energy (frequency). With the information of the detected waves, an image can be obtained (through some complicated methods) or the signals can be analyzed.

Advantages of Microwave Imaging:
- Low Cost
- Non-ionizing radiation




The main clinical application of Microwave imaging is breast cancer. This is due to several reasons:
1. Breast tissues are usually above the 10 cm penetration limit.
2. Breast cancer screening will greatly benefit from a low cost and non-ionizing radiation, as well as less painful acquisition for the patients.
 



Image from here.

More about this technique can be read in:
Fear, E., Meaney, P., & Stuchly, M. (2003). Microwaves for breast cancer detection? IEEE Potentials, 22 (1), 12-18 DOI: 10.1109/MP.2003.1180933
Nikolova, N. (2011). Microwave Imaging for Breast Cancer IEEE Microwave Magazine, 12 (7), 78-94 DOI: 10.1109/MMM.2011.942702

Recent news about microwave imaging for breast cancer:
http://www.sciencedaily.com/releases/2013/04/130423211830.htm

More art inspired by Medical imaging

Marilene Oliver is another artist who is inspired by medical images. She creates sculptures and installations based on medical images. The full portfolio can be seen here. I show in this post some images of her most interesting work:

Great moments in TV with medical images/scanners! #13

Scrubs at its best!

Procrastination with Know Your Images - First 3 months balance

More than 2500 visualizations and 83 posts later, I present you the most successful posts from this blog:

Top 5 posts:
Medical Imaging Conferences 2013
Free Medical Imaging Visualization Software
Shortage of Barium affects medical imaging
Best Medical Imaging Book 
Gorilla CT scan

And press coverage: http://www.hologic3d.com/node/570

Thank you all for reading, "linking" and sharing!

ISBI 2013

ISBI 2013 - International Symposium on Biomedical Imaging - is taking place this week in San Francisco. The complete program is available here and abstracts can be read. The final papers will be available in IEEExplore soon (no date was announced). Unfortunately, this conference has no way to follow it more closely for those who couldn't attend.

Open Access Radiology Education

Open Access Radiology Education is a blog that shows case studies and explains them in a language we can understand: http://radiologypics.com/

Look at this image in the blog:

 A kid just swallowed a penny. Read more about this case here.

Siemens Molecular Imaging

Do you want to know more about Siemens Molecular Imaging?

Check the products here:
http://healthcare.siemens.com/molecular-imaging
and the customer portal here:
http://healthcare.siemens.com/molecular-imaging/customer-portal-resource/administration

I found the growth resources in this page quite interesting, specially the white papers.

Image-Guided Surgery - the future

Medical Imaging meets Minority Report:


This application YScope was developed by a Portuguese company specialized in human interaction: http://www.ydreams.com/ 

More information:
http://www.ydreams.com/blog/2012/07/27/ydreams-and-lisbons-hospital-santa-maria-launch-revolutionary-app-in-the-health-and-tech-sectors/

Stanford Mini Med School

I have recently come across these videos from Stanford medical school, where an introduction about several topics of health and research are talked about. The list of videos can be found here: http://www.youtube.com/course?list=ECD7B0DBD8C28BDEA2 

I post here the one about medical imaging:

Open-Source frameworks for medical imaging

C++ frameworks are great to develop new methods from other previously coded methods. Here are some great frameworks for medical imaging:

ITK Insight Segmentation and Registration Toolkit http://www.itk.org/
As the name states, it is great for segmentation and registration, but also has filters, statistics...

STIR Software for Tomographic Image Reconstruction http://stir.sourceforge.net/
It is a open-source framework to reconstruct data for nuclear medicine.

ROOT Rapid Object Oriented  Data Framework http://root.cern.ch/
It is one of the major open source codes ever developed for Physics, so it is great to use in medical physics oriented medical imaging.

XIP eXtensible Imaging Platform   http://www.openxip.org/
https://wiki.nci.nih.gov/display/XIP/eXtensible+Imaging+Platform+-+XIP
A platform design for rapid development of medical applications including DICOM tools, renders...

MITK Medical Imaging Toolkit http://www.mitk.org/
A framework which comprises ITK and VTK, a visualization toolkit.

A complete list with more frameworks:
http://www0.cs.ucl.ac.uk/opensource_mia_ws_2012/links.html

Databases of Medical Images

Medical Image Databases are great to work on medical imaging processing and sometimes to get a feeling of the images before using real data. I have found some databases in the internet that I consider quite interesting:


Minimal Interval Resonance Imaging in Alzheimer's Disease MIRIAD
This database is focused on Alzheimer Diseases patients, but also control patients.

Mini Mammographic Image Analysis Society Database Mini-MIAS
A database with mammograms and with medical information.

Medpix Teaching database MedPix
A database with examples to teach from CT to MRI.

Retrospective Image registration Evaluation RIRE
A database with images to register and the ground truth to compare.

Alzheimer's Disease Neuroimaging Initiative ADNI
This a huge database of patients images with PET and MRI.

Do you know other good databases?

Best Medical Imaging Book

A great book is a precious help. I have several medical imaging books, which I use to cross information. General medical imaging books which focus on the physics and engineering principles are my favorites. Here is some of them:

Medical Imaging Physics. William Hendee and E. Russel Ritenour.
http://www.amazon.com/Medical-Imaging-Physics-William-Hendee/dp/0471382264

Medical Imaging Signals and Systems. Jerry Prince and Jonathan Links.
http://www.amazon.com/Medical-Imaging-Signals-Systems-Prince/dp/0130653535

The Essential Physics of Medical Imaging. J. Bushberg, J. Seibert, E. Leidholdt Jr., J. Boone.
http://www.amazon.com/Essential-Physics-Medical-Imaging-Third/dp/0781780578

These two are also quite famous and used, but I have personally never used them:

Introduction to Medical Imaging: Physics, Engineering and Clinical Applications. N. Smith and A. Webb.
http://www.amazon.com/Introduction-Medical-Imaging-Engineering-Applications/dp/0521190657

Fundamentals of Medical Imaging. Paul Suetens.
http://www.amazon.com/Fundamentals-Medical-Imaging-Paul-Suetens/dp/0521519152

Do you know any other good books?

Procrastination #4

Another cartoonist talks about medical imaging: http://www.poormd.com/

Radiation dose in medical imaging

During this week, the French doctors in the case of radiation overdose were convicted and I was surprised to read that between 2001 and 2006, at least 400 patients underwent about 8% more radiation than the safer dose. This was mainly because radiation dose in radiological exams prior to treatment was not taken into account. I always thought that medical professionals were aware that several medical imaging exams expose the patient to radiation dose. An extra mechanism for signaling was developed in France after this case.

Aunt Minnie article:
http://www.auntminnieeurope.com/index.aspx?sec=nws&sub=rad&pag=dis&ItemID=607680&wf=1
Guardian U.K. article:
http://www.guardian.co.uk/world/2012/sep/24/french-doctors-trial-cancer-overdose

A quick internet tool gives you radiation dose of typical exams: http://www.xrayrisk.com/calculator/calculator-normal-studies.php
For imaging professionals, there is more information on radiation dose:
http://www.imagewisely.org/

Superbowl and medical imaging?

And because the superbowl was this weekend, I draw your attention to a recent study made with former NFL players. PET studies with FDDNP tracer, developed for Alzheimer disease (AD), have been performed and showed differences between normal subjects and the former NFL players. Nevertheless, the study group is small and therefore, more subjects are necessary to make a bolder statement.




Full article about the study:

FDDNP-PET Shows Brain Injury in Former NFL Players

The Journal of Nuclear Medicine article about FDDNP and PIB tracers for AD  

http://jnm.snmjournals.org/content/50/2/191.short

The Human Brain Project

The European Commission has officially announced the selection of the Human Brain Project (HBP) as one of its two FET (Future and Emerging Technologies) Flagship projects. The new project will coordinate European efforts to address one of the greatest challenges of modern science: understanding the human brain.

"Understanding the human brain is one of the greatest challenges facing 21st century science. If we can rise to the challenge, we can gain profound insights into what makes us human, develop new treatments for brain diseases and build revolutionary new computing technologies."


"According to a recent report, nearly one-third of the European population is affected by some kind of psychiatric or neurological disease (anxiety, mood disorders, neurodegenerative disease, etc.)."

The promoting video is very instructive and I'm very exciting about the database with medical images, of course... I hope this project will be very successful!

PET scan for Alzheimer's disease - new hope

Alzheimer's disease (AD) is still one of the most difficult diseases to diagnose. The diagnosis is based on a mental state assessment and complementary exams can be ordered, but are usually not enough to be conclusive. A new PET tracer has the possibility to change that. The first-and-only FDA-approved diagnostic PET tracer for estimation of beta-amyloid neuritic plaque density when evaluating for AD and other causes of cognitive decline. In Europe, it will also be available in the second-quarter of this year. This tracer can be seen as an evolution of 11C-PIB, as can be read here.

Detailed article from the Journal of American Medical Association (from which the image above was taken):
http://jama.jamanetwork.com/article.aspx?articleid=645188
Official webpage: http://www.amyvid.com/Pages/index.aspx
Why early diagnosis is important? http://www.alz.org/research/science/earlier_alzheimers_diagnosis.asp

Great moments in TV with medical images/scanners! #1

I wish I can say this one day!

Shortage of Barium affects medical imaging

I have just read this week that there is a shortage of Barium (actually Barite) which is affecting medical imaging. Barium is used in Gastro-Intestinal (GI) exams in X-ray imaging. The patients drinks a barium solution or the intestine is filled with a liquid containing Barium by the colon. Barium strongly attenuates X-rays and therefore, the GI is clearly seen in the image. The gif below shows a patient swallowing a Barium solution. Colonoscopy is a typical exam which used Barium (see image below). The Barium shortage has several reasons: increased demand, increased safety regulation in Chinese mines (largest supplier worldwide) and Barite world's supply is disappearing. An alternative is necessary as soon as possible or as I also read recently, we have to extract the barium again from the patient's feces... An excelent post about the topic was written here.

    

This shortage reminds me the helium shortage which is also affecting medical imaging.