Solution to picture of the week #8, and this week’s image November 24, 2007
Posted by tomography in Picture of the week, Radiology.Tags: CT, Ductus Botalli, fetal circulation, Trichophagia
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Ductus botalli is one of three vital shunts in the fetal circulation. The other two are the foramen ovale, and the ductus venosus. After birth, smooth muscle cells in the ductus Botalli react to falling levels of prostaglandin by constriction therefore reducing the flow of blood in the vessel. It is usually completely closed by the fourth up to the tenth day after birth, and it is reduced to what is known by the name of ligamentum arteriosum.
Failure of closure (patent ductus arteriosus) results in a left-to-right shunt in the newborn’s circulation. This in turn allows oxygen rich and poor blood to mix, and may also lead to pulmonary hypertension, heart failure, and arrhythmia. Conservative treatment includes non-steroid anti-inflammatory drugs, for instance indomethacin or ibuprofen. If conservative treatment fails, surgical correction isinevitable.
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You will never guess what this week’s image is, or will You?! Give it a try:
MRI helps surgical planing November 18, 2007
Posted by tomography in development, MRI, Surgery.add a comment
The preoperative magnetic resonance imaging (MRI) image is no longer accurate enough for brain surgery.
Everything changes after the surgeons open your skull. Your brain, and the tumor inside it, no longer fully float in their protective bath of cerebrospinal fluid. Gravity comes into play, as does the atmospheric pressure of the operating theater. The brain responds to these foreign forces, the cerebral tissue sagging, rebounding and changing shape. The tumor that the neurosurgeons want to remove also has changed position.
Thus, the brain the surgeon operates on is a different shape from the one depicted in the preoperative MRI. Of course, once the surgeon begins work, the shape of the brain changes even more. The brain’s changing shape is a problem not only of space, but of time.
In essence, the William and Mary team provides the surgical team with a dynamic computer model of the patient’s brain. In clinical trials, Chrisochoides (mathematician professor at the College of William and Mary) says his team can render a new model in six or seven minutes, but hopes to be able to do so in under two minutes.
We want to help the neurosurgeon make an informed decision of what to cut, where the critical paths are, what areas to avoid, he said. I’m neither a neurosurgeon nor a doctor, so the contribution of my research is to make this distillation of objects really, really, really fast.
The process begins with the acquisition of a variety of images before the surgery – images which are otherwise unavailable in the middle of the procedure. Low-resolution intraoperative data allows the tracking of the shift of brain matter and calculates how to change the preoperative images accordingly.
The brain, of course, is an elastic object.
If you push it, -Chrisochoides said-, it takes energy and then after a while it settles down. We can calculate the place where it settles by solving the partial differential equation. Mathematicians can tell us that there is a solution, but they cannot tell us what the solution is. There’s no such thing for this equation. There’s no analytic solution. So we have to approximate.
Chrisochoides approximates the geometry of the patient’s brain by tessellating it into triangles in three dimensions, or in other words, generating a mesh representing the brain. Users wear 3D glasses to examine projected images of a brain. The glasses give the audience a striking 3D effect, showing off the curves of the vector arrows indicating how displacement was acting on the brain.
Source: NSF
Solution to Picture of the week #7, and this week’s image. November 13, 2007
Posted by tomography in Picture of the week.add a comment
Pneumothorax is very painful and potentially life threatening. It may occur on the bases of several underlying diseases, but mostly due to trauma (e.g. broken ribs), rupture of an emphysematosus bulla, trans-thoracic fine needle biopsy, or as a result of artificial respiration. It is life threatening because it acutely diminishes lung capacity and causes the dislocation of the greater vessels. Most patients complain of a sharp, sudden pain and may become cyanotic very quickly. Dislocation of the mediastinum may result in insufficient cardiac output, and if blood circulation does not match demand, the patient may collapse or even die.
End here is this week’s image:
Starting next week, you will find 5 pictures per week under the “Quiz” page on the main menu. Please, email us your answers; do not write them on the comment section! This nuclear medicine quiz is going to last for 5 weeks, and it is open to everyone, but only students attending the University of Debrecen can earn extra points on their final exam. Good luck!
Grab it like Tom! :-) November 12, 2007
Posted by tomography in development, Innovation, Surgery, What tomorrow brings?.add a comment
The use of 3D imaging in the medical field has proven to be a boon to doctors when diagnosing patients, and 3D models of the human body have assisted medical manufacturers in developing better medical devices and treatments. Now researchers at the Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut (HHI) in Berlin have developed a display that combines a 3-D screen with a non-contact user interface that allows images to be rotated by hand gestures much like the display Tom Cruise played with in the film Minority Report.
The display was developed for medical use where traditional ways of interacting with displays through touch runs the risk of compromising the sterility of work environments. With the newly developed non-contact image control system a physician can rotate a three-dimensional CAT scan image that appears to float before their eyes with a gesture of their fingers, while with another gesture they can click onto the next image.
The system works by utilizing images from three cameras, two of which are installed above the display and a third which is integrated into the frame of the display. The two cameras above the display see the pointing finger from different angles, allowing image-processing software to identify the exact position of the finger in a three-dimensional space. The third camera scans the user’s face and eyes to identify the inclination of the user’s head and the direction in which the eyes are focused and the associated software generates the appropriate pair of stereoscopic images for each eye. The cameras record one hundred frames per minute so, even if the user moves their head, the system instantly adapts the images!!! In this way, the user always sees a high-quality three-dimensional image on the display, even while moving about. This is essential in an operating theater, and allows the physician to act naturally when carrying out routine tasks.
Source: MedGadget
Innovation in moving organs MRI November 10, 2007
Posted by tomography in Cancer, Innovation, MRI, Radiology.add a comment
Isis Innovation, a spinoff of the University of Oxford, has developed new software for existing MRI machines to reduce breathing artifacts in medical images of moving organs, such as liver that sits just below the diaphragm.
Typically in magnetic resonance imaging, to acquire an image of the whole liver, you would need somebody to hold their breath for 60 seconds. Chances are that the patient is not particularly healthy, so it is expecting quite a lot. In existing methods of magnetic resonance imaging, the patient holds his or her breath for 20 seconds at a time while the machine takes an image of the liver in slices. After 60 seconds the slices are then put back together to form a whole image. Because the liver may move in between breath holds, some of the slices may overlap, or they might be put together incorrectly.
The researchers claim the new technology would eliminate this problem by aligning the slices of the liver image to a reference volume, an outline image of the liver taken before the more detailed slices, automatically checking for overlaps or missing slices. The reference image is acquired with a T1 weighted fast spoiled gradient echo (FSPGR) image. T2 images always take longer to acquire, so you break it down into several. You need both the T1 and T2 images to make the diagnoses, as they provide complementary information.(Source: The Engineer)
Worldwide over 1 million people are diagnosed with colorectal cancer annually, with a great proportion developing metastatic liver disease requiring follow up with abdominal Magnetic Resonance Imaging (MRI). Radiographers and Radiologists have raised breathing artefacts as a major issue in accurate diagnosis and estimation of tumour volumes. With current methods, in 19% of cases at least 5% of the liver is missed. Indeed, for lesions between 6 and 30mm in diameter, 3% are missed completely with a further 21% being incorrectly staged, leading to false diagnosis of disease progression or regression.
Working closely with clinical staff, Oxford scientists have used their expertise to find a robust solution. On the left, is an image that is reconstructed from a series of slices. The liver boundary is not smooth and the tumour seems to consist of multiple parts. After application of the Oxford technology, the liver outline is much smoother and the tumour well represented by a spherical shape. The technology significantly improves patient comfort by reducing scan duration and avoiding recalls. The improved quality and accuracy of the dataset provides meaningful estimation of tumour volumes for more precise chemotherapy dose calculation. It is estimated that 25% of the annual 2 million abdominal MRI scans worldwide would benefit from this innovation. The invention reached the Finals of the 2007 Medical Futures Innovation Awards and was also the subject of a recent paper in the European Journal of Radiology. (source:Isis Innovation)
The advantage of the technique is that it is applicable to organs subject to large uncontrolled amounts of motion. An extension of the technology would be the imaging of the head or body parts of patients who suffer from Parkinson’s disease and cannot control their motions.
Getting closer to replicators November 10, 2007
Posted by tomography in development, Future, Off Topic, What tomorrow brings?.add a comment
The first affordable Desktop Factory 3D printer is just about to ship!, paving the way for even more sophisticated manufacturing in the future. Starting out with powdered plastic, it layers the plastic material so precisely that it exactly conforms to the software 3D model that serves as its guide. This home 3D printer brings us closer to the day when we’ll have replicators like those on Star Trek: The Next Generation, making entire meals at the touch of a button and creating complex objects from simple materials. In the meantime, soon you’ll be able to download spare parts for toys and build them in a few minutes, or even prototype your own designs, right in your home.
Ever since the advent of 3D printing, researchers have been trying to figure out how to replicate organs and bones for use in surgeries. Printed organs are still many years away, but researchers in Japan have already begun testing 3D-printed bones on human patients with face or skull injuries.
Someday we may be able to replicate our own skeletons on affordable 3D printers.
source: Charlie White, S.E. Kramer
Tomographyblog.com mentioned on Tiromed.com! November 8, 2007
Posted by tomography in Blogroll, Off Topic.Tags: Tiromed, web 2.0 community
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There are several web based communities, where you can create your own profile, upload your photos, and find others who share your interests. But beyond Facebook, Iwiw, BeBo and such there are some that are tailored for professional users. One of these is Tiromed, which is aimed at people who are related to the medical field. If you are a physician, medical student, or even a pre-med student your place is at Tiromed! Here you may ask for a mentor, or even become one yourself. You can upload your CV, search for job opportunities in your community and beyond, or even find people that you can collaborate with on your research. Tiromed is for everyone regardless of where you are attenting school, or your diploma.
So I had joined Tiromed a little while ago, and later I was asked by one of the founders, Max Sanel , if I’d be interested in being featured on their TiromedSpotlight. Certainly, I said yes, and embedded in my profile is the name of our blog, tomographyblog.com! 
Check out the writing, but hurry it is only available until next week.
X is for Ray November 8, 2007
Posted by tomography in development, Off Topic, Radiology, Tomography.add a comment
This day – Nov. 8. – in 1895, german physicist Wilhelm Roentgen is working in his laboratory in Würzburg when he accidentally discovers the X-ray.
Roentgen was conducting experiments with a Crookes tube — basically a glass gas bulb that gives off fluorescent light when a high voltage current is passed through it — when he noticed that that the beam cast a greenish fluorescent light on a screen nine feet away, despite the tube being shielded by heavy black cardboard.
Roentgen concluded, correctly, that he was dealing with a new kind of ray, one that cast the shadow of a solid object when passed through an opaque covering from its point of origin. Not knowing what kind of ray he was dealing with, exactly, led him to call it an X-ray. The name stuck.
This “X” earned him a noble prize in physics in 1901.
source: wired.com
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