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Diagnostic Radiology - Science topic

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This question is not intended for detection of subdural hematomas and hygroms in case overdraindage is suspected. Also I think MRIs are not sensitive to guide fine adjustment. So they offer little benefi in this direction, except in case overdrainage is signficant; like meningeal enhancement as an example.
The question is meant for the yearly follow up of a patient whom we think is well adjusted. How to comment on the decrease or increase of the hyperdensities of trans ependymal diapedsis as an indicator of improvement or worsening. What are the results of research on this point?
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I will be waiting for radiologist answers, but I will add; are old densities have same chance to disappear as the rather recent densities?
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Call for Book Chapters:
Intelligent Diagnosis of Lung Cancer and Respiratory Diseases
Editors:
Wellington Pinheiro dos Santos, Federal University of Pernambuco, Brazil
Juliana Carneiro Gomes, Polytechnique School of The University of Pernambuco, Brazil
Maíra Araújo de Santana, Polytechnique School of The University of Pernambuco, Brazil
Valter Augusto de Freitas Barbosa, Federal University of Pernambuco, Brazil
Introduction
The series of books Intelligent Systems in Radiology aims to present the principles and advances of diagnostic techniques in Radiology based on Artificial Intelligence, from the perspective of the advent of Digital Health. The series consists of three books. Each of them is divided into two parts: one dedicated to theoretical foundations and the other to radiological applications in the real world. This call for chapters is dedicated to the first volume.
The first book, Intelligent Diagnosis of Lung Cancer and Respiratory Diseases, is dedicated to the diagnosis of diseases of the respiratory tract or those that seriously affect the respiratory system. In the first part, the physiological foundations of the respiratory system and the formation of radiographic images and x-ray computed tomography are presented. Principles of respiratory diseases are also presented, including lung cancer, viral and bacterial pneumonia, tuberculosis, and Covid-19. In addition, the principles of pattern recognition and machine learning and the main theoretical and practical tools are also briefly presented, and libraries in the programming languages ​​Python, Java and Matlab are also commented. The second part presents innovative works and systematic reviews of intelligent applications in the diagnosis of lung cancer, tuberculosis, viral and bacterial pneumonias, and Covid-19.
No publication fee will be demanded from the authors of the accepted chapters.
The Objective of the Book
This book series is intended for readers interested in intelligent systems to support diagnosis in Radiology. The series is composed by three books. The first one, Intelligent Diagnosis of Lung Cancer and Respiratory Diseases, the focus of this call, is dedicated to diagnosis of respiratory diseases. The second book covers the diagnosis and treatment of neurodegenerative diseases. The last book is dedicated to Neuroscience applications, from clinical to affective computing applications. All books present comprehensible theoretical fundamentals both from clinical and computer engineering perspectives.
Target Audience
This book is intended to everyone who needs to understand how radiological images, neuroscience and artificial intelligence could work together to generate solutions in the context of intelligent diagnosis support and applied neuroscience and how intelligent systems could process and analyze images to improve early diagnosis and, consequently, prognosis of diseases.
Recommended Topics
Contributors may submit proposals on topics that include, but are not limited to, those listed below. The chapters may take various forms.
Part I: Fundamentals
1. Physiology of the respiratory system
2. Fundamentals of x-ray images and computerized tomography
3. Principles of lung cancer and respiratory diseases
4. Principles of pattern recognition and machine learning
5. Principles of image processing
6. Computer-aided image diagnosis
7. Computational tools and tutorials on Python, Java and Matlab
Part II: Applications
1. Lung cancer
2. Tuberculosis
3. Viral and bacterial pneumonias
4. Covid-19
5. Emergent imaging techniques
Submission process
Potential contributors are invited to submit, on or before January 31, 2021, an abstract of 300 – 400 words proposal (excluding references) that presents the intended contributions of their chapter, intended approach and methodology.
In addition, authors should provide the following:
· Proposed titles of their chapters
· The theme (see above) of their intended chapters
· Full names
· E-mail addresses and
· Affiliations
Chapters submitted must not have been published, accepted for publication, or under consideration for publication anywhere else.
Proposals and full chapters should be submitted via EasyChair according to the following link:
By February 15, 2021, potential authors will be notified about the status of their proposed chapters. When accepted, the authors will receive further information regarding the submission process, including the formatting guidelines.
Full chapters should be submitted on or before April 16, 2021 in a single attached Word or LaTeX file with the Copyright Letter. References should follow IEEE standards. The authors should follow the formatting rules in this link:
Final submissions should be approximately 4,000-5,000 words in length, excluding references, figures, tables, and appendices. All chapters will be peer-reviewed. No fees will be demanded from the authors at any stage.
Full chapters are expected to be at least 25 pages in length, font size of 10pt for the abstract, 12pt for the body text, and single-spaced paragraphs.
Key deadlines
• January 31, 2021 - Proposal submission deadline (300-400 words)
• February 15, 2021 - Notification of acceptance of proposal
• April 16, 2021 - First draft of full chapter submission
• April 30, 2021 - Revision submission
• May 14, 2021 - Final acceptance notification
• December 2021 - Publication
Publisher
The book will be published by Bentham Science Publisher until December 2021.
Please address any questions you may have to Prof. Wellington Pinheiro dos Santos - wellington.santos@ufpe.br.
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Dear Wellington Pinheiro Dos Santos, I am now dealing with a book chapter dealing polymeric nanoparticles (PN) for solid cancer drug delivery. During my bibliographic processing I found appreciable bibliographic material on the same PN used in cancer diagnosis for image contrast mainly. However, in the recommended parts of your Book no one is concerned by this aspect. So, what do you think, if you think this is feasable I Can be in charge of that. Kindest Regards
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I am interested in obtaining a spectral CT dataset to test a reconstruction algorithm. 
Thanks. 
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I am trying to evaluate the performance of a screening tool for meningitis. For this purpose, I have separate data on bacterial, viral and TB meningitis. I am interested in calculating the aforementioned statistics separately for these as they are clinically very different from each other. However, my control arm consists of patients who were suspected of meningitis but were found to not have the disease. I am not sure whether is it appropriate to use the same control arm as "negatives" while calculating these statistics separately for each type of meningitis. Please let me know if you have any suggestions. Many thanks in advance!
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My suggestion would be to forget for a moment the terms sensitivity, specificity, PPV, and NPV because they can be quite confusing when dealing with more than one type of condition. Instead, focus on the value of the test that you want to measure, i.e. which test is preferable over another test with different test characteristics?
For that you need to put a value on each possible test result. You can approach it in either way: as positive contribution to a patient's health or as 'cost' due to an erroneous test results. Both these approaches should result in the same preference. It is probably easiest to approach is from the cost side:
- What is the disadvantage of getting a positive test result if you don't have meningitis?
- What are the respective disadvantages of getting a negative test result if you do have either of the three types of meningitis? I assume that those three disadvantages are not of equal value because otherwise you would not need to bother with the different types of meningitis
Generally the disadvantage of a false negative is much larger than of a false positive, therefore your evaluation should reflect that you are willing to tolerate more than 1 false positive if that is needed for finding 1 more true positive.
Health economists tend to estimate preference through QALYs. Maybe you have a better way to determine the relative value of the four different types of test errors in your example.
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I think if frequency is increased resolution increased, is it correct?
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An ultrasound image has poor resolution because the speed of sound varies by less than 10% and the speckle noise but with the new technologies overcome this problem
regards
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Hello,
I am trying to build an application to scrape information off of the DICOM images, this is mainly CT dose values and store them in a MySQL database.
Just wanted to ask if anyone tried this and can help to set up.
Thanks.
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If you have access to all DICOM images in file system use a command line tool that dumps the information your interested in from all files (e.g. write a script that uses the command line tool).
If the DICOM images are stored in a PACS or any other kind of DICOM network node you have to transfer them first to your local hard drive and proceed as described above.
If you want to develop an application that does the above look for a DICOM library that fits your programming language and needs.
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In medical imaging we are using ultrasound for detecting abnormalities in unborn babies. Can we do same by USCT?
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No of course because of the radiation hazards
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I could come across a few studies that perform AP/PA Chest X-ray view classification using machine learning. However I'm puzzled if this is a truly noteworthy/real problem in the clinical setting. I would like to know whether the radiologists find it hard to distinguish between AP/PA in the clinical setting and an automated system is really required in this regard.
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The principal reason is that the difference in position causes different amounts of magnification of cardiac size. With a PA chest x-ray, the heart is close to the image receptor, and magnification is minimal. With an AP chest x-ray, the heart is further from the image receptor, and appears larger on the image. When evaluating the possible presence of cardiomegaly, only a PA view should be used.
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Can anyone share edx-files (Phoenix) for MRI avanto 1.5T about the abdomen (hepatobiliary system, gall) ?
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i found that MRI siemens standart protocols is out of good imaging. This is may be my fail in understanding but nothing helps. so I hope edx format will help me.
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a. Allow them to transfer into DR.
b. Make them finish their IR residency commitment first.
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Ask them what about IR is less appealing to them; what has deflated their interest in IR; many times a particular instructor or professor can be harder than the IR resident anticipated. Getting to the basis of their thought process regarding seeing themselves in IR often will be a key to helping them in their decision making.
Dennis
Dennis Mazur
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IR residency will be challenged by being one of the most specialized residencies in the NRMP match and yet not having a required clerkship in the medical school curriculum. How do you plan on ensuring that students have adequate exposure to IR prior to making their career decisions?
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A good lecture session for half a day or one day should be informative.
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a. Heavily. We will likely recruit at least one resident per year on the Independent Pathway.
b. Sporadically. We will likely use it only to fill in gaps every few years.
c. Seldomly. We will likely never use that pathway to recruit.
d. We haven’t thought about this.
e. We won’t have an IR residency.
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e. We won’t have an IR residency.
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Do you currently participate in any of the following activities to improve medical student exposure to IR:
a. IR Student Interest Group
b. IR Sub-Internship
c. IR Electives
d. Participation in an IR Medical Student Symposium
e. IR faculty teaching in the M1-M3 medical school curriculum
f. Encourage student engagement in the SIR RFS
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A medical or surgical rotation should include students on rounds with the team to see all radiographs (interventional or non-interventional) taken on each day of the medical student rotation on any service where radiographs are taken.
The radiologist should begin questioning of the interpretation of the radiographs with the medical student going first.
Dennis
Dennis Mazur
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Given the varitey of imaging methods available between clinical methods that are use to detect various type of cancer, so it's important to note whether these methods are aggressive or not and how much harmful they are?
Certainly, imaging techniques by radiation can have destructive effects on the cancerous tumor, But does colonoscopy or endoscopy imaging also have negative effects on the cancerous tumor?
And whether doing it in the false and inexperience manner will have negative effects?
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Colonoscopy when performed by experienced operators has no major complications. Its usefulness exceeds by far any major risk.
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I apply algorithm to segment the CT lung -axial images from background and these images are taken from https://wiki.cancerimagingarchive.net/display/Public/LIDC-IDRI 
LIDC-IDRI - The Cancer Imaging Archive (TCIA) Public ...
Summary The Lung Image Database Consortium image collection (LIDC-IDRI) consists of diagnostic and lung cancer screening thoracic computed tomography (CT) scans with ...
My question is that if anyone know a sit for CT  segmented lungs in order to evaluate my algorithm. 
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agreed with Hayder
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Are there scoring method used in abdominal CT to assess image quality as well as pathology in the abdominal organs?
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Thank you sir, please are there empirical evidence from published data? Please. @ Joseph Zira Dlama
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In Image segmentation, there is a method named 'Active Contour model' which is used to segment deformable model.In 'Active contour model', there are some techniques where the relation of a particular point is found out and it is multiplied by outward unit normal vector of a curve.
What is the best way to find that?or Do the geometrical method like finding tangent and then normal is to be used?
Is there any relation of outward unit normal vector with Signed distance map?
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@Wolfgang Reichl: Hi, gradient in which direction? X ,Y or both?
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Dear all,
Hi,
Does anybody knows segmentation ground truth  of Breast Ultrasound images
Thank you in advance.
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there is a good database with ground truth provided by SIIT biomedical unit , Thammasat university, Thailand 
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Is any data-base that list f factor (roentgen-to-rad conversion factor) for different materials? 
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Daryoush,
You are correct in stating that it is the ratio of the mass energy absorption coefficients.  You can look at a lot of these values at the NIST web site:
Look at Table 3 for elements and Table 4 for compounds and mixtures including some standard tissues.
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Hi.
Can a loose metalic object, from a patients pants or so, affect the homogeneity of the magnetic field? And affect the quality of the image, if it's stuck to the scanner while scanning?
Thank you :)
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2 possible effects:
1. disruption of magnetic field homogeneity and/or gradient linearity, leading to spatial distortion and/or rf inhomogeneity.  Magnitude of effect depends upon size, location and magnetic susceptibility of metal.
2. arcing (sparking) caused by metal rubbing against housing, caused by vibrations during scanning.  This will cause various noise patterns in the image, depending upon when the arcing occurred during the data acquisition (K space filling). Even non magnetic metal can cause this.
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Are you a family physician or pediatrician? if yes, what would be your main reasons to request an advanced imaging test in pediatric patients?
(Please consider orthopedic cases only)
Thank you!
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this is so easy to answer in hindsight with the retrospectoscope. Or even better on a desk running analysis on a population based retrospective study....however in real life where physicians must decide, in broad day light or night alike; some times under time pressure, some times biased by a recent case, sometimes afraid of medicolegal implications ....it becomes harder to only order the best exam
off course there will be overuse, how else can one be sure that all necessary examinations have been carried out... 
and yes it is frustrating that we have examinations and time and effort spend when in hindsight it could have been done without... however ...better safe than sorry and first don't harm are still relevant 
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I am looking for a colleague to share experience and advice.
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In case of suspicion Crohn , we prefer, the first one, US study of the last ileal loop (SICUS). The RMN secondarily . If your service does not have a sonographer delicate, resonanc, with the study of the loops, is indicated .
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Hi every body
In our radiotherapy center, there is a Varian Linac 2100C/D with energy  6MV. However the Flattening Filter Free (FFF) mode is not available. I need PDD, profiles  at several depth measured for fields 2x2, 4x4, 6x6, 8x8, 10x10, 20x20, 30x30 and 40x40 and also Sc and Scp for Varian 2100C/D 6MV energy without Flattening Filter (FFF) for comparing to simulation data obtained by Beannrc code.
Best regards
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Dear Sergio Faermann 
Thanks for your response. you are right two accelerators are not same and of course we can not remove FF, I like to comprise some simulation code , however for validation of each Linac I need PDD and profile measuring data. So for this data, we are able to compare two code which are validated by same measuring.
by the way, thanks for your attention.
beast regards
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Radiographically, keartocystic odntogenic tumors ( multilocular or multilobular )have a similar radiogrphic image to ameloblastoma, are there a diagnostic  radiological features that help to differentiate between the 2 lesion ?
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I concur with everyone's contribution and I hereby commend your effort.
Permit me, to take us back to the question, and summarize the answer. ... " Are there diagnostic radiological features that help to differentiate between KCOT and ameloblastoma? Answer, : There are radiological features that are suggestive of differences between the two and may help to differentiate between KCOT and Ameloblastoma but these are not diagnostic.
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I think direct measurement with anthropomorphic phantom is the best way, but this method needs expensive phantoms and is time consuming according to calibrate and read TLDs. Is an alternative method to asses organ doses with less difficulties?
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You might want to look at the method developed by Walter Huda and me.  Using the free-in-air isocenter kerma, we measured the ratio to organ doses in multiple anthropomorphic phantoms.  Very easy approach to organ dose:
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I have been studying about X-ray Fluoroscopy imaging technique lately and it's immense use in medical diagnosis and therapy. However I find there are many disadvantages to it, such as we can only see a 2D image of a 3D object. Minor details are hard to acquire and/or observe on screen.  Monochromatic display is also another problem as I see it.
What type of improvements are being currently being researched to this imaging technique? I have hit dead ends in my search through google, pubmed, Radiographics Journal & so on.
Please let me know. Thank you.
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Thank you all for your suggestions. They were very helpful. From the discussion with my research colleagues, it seems that most people are inclined towards 3D imaging developments of Fluoroscopy. Thanks again.
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Anybody interested in a simple tool for automated brain tumor segmentation from multimodal MRI images, please check out our BraTumIA (Brain Tumor Image Analysis) software. It can be downloaded from http://www.istb.unibe.ch/content/research/medical_image_analysis/software/index_eng.html
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It requires manual set up for each patient, at the moment we do not offer it as a script for running on a larger database yet
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Hi all,
If I form an array of individual point acoustic sources of same frequency and same output pressure with equal spacing between each other, how will the total pressure from the array depend on the number of individual elements if all the elements are triggered together? Is it a linear relation? The individual point sources will be placed close proximity to each other and all the sources will be triggered at the same instant so that the phase difference can be avoided.
Please help me if anyone has an expertise in this area.
Thanks in advance,
Jose
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Jose,
You're answer depends on the spacing of the elements and the distance from them you are interested in. There will be large pressure fluctuations within the Fresnel zone before a settled Fraunhoffer region emerges. The position of this will depend upon the interactions of the waves from the sources with each other, one of the governing parameters will be your acoustic source spacing. It will be fairly simple to write a model in Matlab to study the relationships yourself using a Rayleigh-Sommerfeld model.
For more information I highly recommend the book "Fundamentals of Ultrasonic Phased Arrays" by Schmerr
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Contrast agent for CEUS: SonoVue
1,5 Tesla MRI
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Yes of course there are some. Here below is one ref but you could find others easily.
Solid focal liver lesions indeterminate by contrast-enhanced CT or MR imaging: the added diagnostic value of contrast-enhanced ultrasound.
Quaia E.
Abdom Imaging. 2012 Aug;37(4):580-90.
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I am particularly worried about the lack of interest of the authorities in Israel ,on the image quality standards and accreditation of medical physicists in diagnostic radiology.Do you have the same situation in your country?Can you suggest ways to improve this situation?
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In India, though we have good amount of experts in the domain of radiology, medical physics but are mostly into their private labs as entrepreneurs. They rarely have time to contribute for the research and development in any form.
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In pulmonary CT angiography, different protocols are applied with different contrast volumes. However, if we know the physiological average amount of CM that fills the pulmonary artery down to the tertiary branches, we can do good exam.
In timing the scan, we need to exclude the CM-filled SVC and the left side of the heart in order to avoid artifacts. So knowing the physiological CM volume on average patient and adjusting the scan time given the size of the chest, and heart rate, a good timing of pulmonary angiography can be performed.
One more technical factor is calculating the scan time in testing bolus technique. This method ensures a maximum concentration of CM in the pulmonary trunk. But giving that we start the scan in the caudo-cranial direction, the CM may be not maximum by the time PA is scanned. It is said that 5 seconds should be added to the time to peak, I don't understand why 5 second? In fact, rationally some seconds should be deducted from the time to peak because this time is consumed by scanning the chest from the base till it reaches the pulmonary artery.
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We use test bolus with ROI in pulmonary trunk and add 2 secs to peak time as delay. Then 30 ml are sufficient for CTPA (on Flash the scan of thorax takes about 3 secs), but aorta is "empty" . However there are plenty of possibilities.  
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At a certain transducer power level the maximum intensity as well as the average intensity in a volume of interest drop rapidly (instead of in a linear manner, as I would have expected). I wondered whether this is due to some kind of rescaling in 3D-US software, but couldn't find any information on that.
Image below shows the same effect observed on a Philips SONOS 7500 3DUS. 
I am working with the following setup: Ultrasonix SonixTablet, running 'Porta SDK 6.07' on it, 4DL14-5/38 linear 4D transducer. Checked the manual for answers. I am taking pictures of metallic surgery tools in soft tissue, such as ex vivo pig hearts.
I'd be happy about any information(paper, book,..) related to that topic.
Thank you for your help
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I googled the probe you use and It seems to be ok for the job you are working on.  Did you use a good transmitting media, I mean ultrasound jel - plenty of it...  You may try to put ex vivo pig hearts in a plastic container filled with ultrasound gel, I have tried plain water for some other experiments, ultrasound gel may even work better.  
You can check my experimental model ( A model for basic ultrasound set-up and training for 3D/4D ultrasound scanning
K E Karaşahin · M Ercan · I Alanbay · U Keskin · M Dede · M C Yenen · I Başer
Ultrasound in Obstetrics and Gynecology 03/2011; 37(3):371-2. )
I believe it will work for you.  Submerge the pig heart  about 4- 5 cm away from the tip of the probe, make sure there is plenty of gel between the heart and the probe.  Try to avoid air bubbles. 
You can also try to fill the plastic cup with jello solution, and observe after it solidifies.  
4 D imaging is real time so you have to be patient, do not move the probe around quickly.  3 D is easier but still requires a stationary probe.  Get a clear 2 D image first.  Then use 3/4 D .
Use small volume or interest for better results (you get higher frequency and better resolution).
Good luck.  
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As a radiologist, interested in cancer imaging, i came across a publication
(Atoum, 2012), that could show correlation between elevated CA 15-3 and stage II-III breast cancer.
Of course CA 15-3 cannot detect early stage breast cancer and is therefore not recommended in screening (Duffy, 2006). 
But sometimes it can be challenging to find a 2-3 cm diffusely infiltrating breast cancer in asymptomatic - especially premenopausal - women with dense tissue (Buist, 2004. Kolb, 2002).
A serum marker might be helpful to select patients for further evaluation, e.g. Breast-MRI, tomosynthesis or ultrasound, in order to find “medium size” breast cancers, that otherwise would go undetected by mammography for quite a while with worsening prognosis.
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Thank you for your contributions! Yes, the idea is a simple blood test as a guide to apply further evaluation. maybe a good example is HCC-screening using AFP in patients with liver cirrhosis at risk of hepatocellular carcinoma. the key for success is a proper selection of patients with a high pre-test probability.
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Some molecules are secreted from the gastro-intestinal mucosa to the gastro-intestinal lumen, and eventually ends up in the feces. Some positron emission tomography (PET) tracers may be secreted into the GI-lumen in this fashion, and therefore potentially confound the use of these tracers for imaging cancers and other pathology in  the GI-tract. I would appreciate some good references for papers or book chapters, which describe the principles and mechanisms of this type of secretion. Thanks. 
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I am studying automatic segmentation of pathologies in the brain, for which I would need a manually segmented and labelled set of CT brain scans. Does anybody know of such a segmented dataset?
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The Cancer Imaging Archive might be worth a try.
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Is there a GATE actor that will let me complete a simulation once a certain number of events occurs in a particular detector?  I am looking to determine dose delivery based on clinical PET scans which have been performed.
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Hi,
For this purpose, I think there is what we call kill actor in GATE simulation platform !
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Gangionic plexus (GP) have an associated with initiation and maintenance of AF. Is there a way to accurately locate them with out high intensity frequency (HIF) such as nuclear imaging - MIBG?
If there is a accurate method of locating GP then what methods are currently being employed in the clinical setting which are reproducible and accurate at the same time?
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Your answer surprises me. With a dose of 80 MBq at rest and a normal collimator, ignoring decay / scatter / attenuation / part of patient outside FOV / geometric efficiency / poor algorithmic efficiecy, your 'true' data compromises at most 6E5 events amidst a lot of noise. Given that likely half the photons are scattered, half are attenuated and three quarters will be outside the field of view and that probably the GP will compromise less than 1.5% of the MIBG uptake within the field of view, I am not convinced that it is at all feasable. 
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If you are a clinical medical physicist, what are the major challenges in your department in order to perform invivo dosimetry for each individual patient when he/she is receiving radiotherapy or undergoing for a diagnostic radiological procedure?
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Hi Shakardokht,
I don't have any experience with dosimetry in diagnostic radiology but I have been doing radiotherapy in vivo dosimetry (TLDs and GaF film) for a while now.  Narayan's work is really intra cavitory dosimetry, which, these days is not performed regularly as modern planning systems can predict/estimate the doses to OARs quite accurately. I have found eye lens dosimetry to be the most challenging one. In vivo dosimetry in this case uses surrogates on the skin to estimate dose to lens at depth. The other issue the uncertainty in dose estimation using TLDs due to the angular dependence of TLDs. Not sure if a phantom exists where one could place TLDs in place of lens and then performs dosimetry by putting TLDs on the skin and comparing the doses from on the skin TLDs to the TLDs placed inside the phantom where the lens is located. The other anatomical areas where in vivo can be challenging are the nose and ear, especially when MV electron are used to treat skin tumours in these areas. The issues to consider here are the electron backscatter, uneven surface and the lack of tissue. There probably are other areas/issues such as dosimeter preparation readout etc. which can also be challenging.
Cheers
Vinod 
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i.e. CR/DR log/linear
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The CR systems uses a log amplifier. There is one advantage as this roughly corrects the signal to be proportional to the density of everything in the beam i.e. inverting the effect of the exponential absorption properties. This is useful to know if you are looking at a raw clinical image (with linear LUT), it can be easier to view after applying a log transform to the images.
There is more and I am stretching my brain for this one, but there are some advantages in terms of noise for log amplifiers. I think linear amplifiers are used for DR as log amplifiers would amplify the electronic noise in low signal regions - this is not an issue for CR as there is negligible electronic noise.
Either way the images are generally presented to the reader with a sigmoid look up table.
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Most radiological equipment and accessories used in diagnostic radiology are composed of  lead e.g lead glass, lead aprons, grids etc. Lead is known to be harmful based on some research findings. So how can we best dispose out-of -use lead materials or is it proper just to dispose them to the environment? 
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If  many  radiological  accessories  are  made  of  lead, that  presupposes  that  contact  with   it  is  not  harmful  in  its  basic  solid  form. The  harm  documented  in  literature  is  from  inhalation  as  powder  or    ingestion  when  dissolved  in  a  solvent.
The  question  also  arises  as  to  how  lead  from  radiological  practice  can  accumulate  to  such  a level  as  to  constitute  an   environmental  hazard.  It  is  not  a   use-and-dispose  consumable  by  the  way  but  made  to  last  ad  infinitum  unless  its  integrity  is  compromised. In  developing  countries  it  would  be  rare  to  see  any  disposal  of  lead-based  radiological  materials  aside  distorted  grid  and  compromised  lead  aprons.  And  even  then,  where  will  the  quantity  that  can  constitute   a  serious  environmental  hazard  be  found? Only  in  metallurgical  companies  that  handle  lead. It  is  the  scrap  metal  from  such  places  that  we  should  worry  about  more.
It  is  my  opinion  that  that  lead  can  be  disposed  normally  in  a  garbage  heap  as  long  as  it  is  not  close  to  a  drinking  water  source. It  can  also  be  buried  deep  down  in  the  soil. Nevertheless, this   calls  for  a  research  to  know  how  it  is  being  disposed  and  the  immediate  and  eventual  environmental  impact  of  non-recycling  in  ones  immediate  environment.
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Can anyone recommend a good publication regarding an influence of the number of counts on SPECT image quality?
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Chapter 9 of Physics in Nuclear Medicine by Simon R. Cherry, James A. Sorenson, Michael E. Phelps discusses counting statistics in some depth. You can preview the book on Google books to see if it the correct content for you.
A review article by E. Gordon DePuey, "Advances in SPECT camera software and
hardware: Currently available and new on the horizon" discusses advances in software that enables lower counts to be used, such as iterative reconstruction, resolution recovery and noise compensation...
I hope this information is useful
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Digital Subtraction Angiography (DSA) images suffer from inhomogeneous contrast agent distributions within the vessels caused by unequally distributed contrast agent.
Is it right/ wrong to apply anti-concentration diffusion model for 2D DSA images? and why?
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I don't know what anti-concentration means, but diffusion of contrast agents is a 3D phenomenon. Angio X-ray images are 2D conical projections of a 3D scene. A pixelvalue in such an X-ray image is the result of the electron-density of all tissue in the path of a beamlet plus some scatter.
So, I would say: doing some diffusion-based modelling in 3D is valid, but in 2D projections it is not valid.
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"Nominal anode input power" is a term describing characteristics of x-ray tubes, defined in IEC 60613 standard. Does it have any official translation to German?
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It should be: Nominelle Anodeneingangsleistung
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Personal dosimeters (viz. TLD) are used for monitoring radiation exposure. As in the current Radiology curriculum, residents hardly work in an environment where radiation monitoring would be required (except DSA), what is the current guideline for personal dose monitoring?
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Yup, thats exactly the practice in Malaysia, a film badge dosimeter worn by every employee at the radiology department and we are given 14 days of extra leave compared to others who work in other departments. The badges are collected by the radiation supervisor.
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From a 41 year old healthy male in the emergency department due to encephalopathic state with confusion, then seizures. Lumbar puncture with 4 cells (mononuclear) and normal protein and glucose count. Still no answer of OCBs or viral serology. Toxic screen positive for Benzodiazepines and Cannabis and known use of synthetic cannabinoids.
Anyone have an idea?
Here the attached MRI:
Thanks.
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It's likely to be a toxic extrapontin demyelination case. The history of the patient also suggest primarely this diagnosis.
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Can any cardio thoracic surgeon and radiologist please tell if they experience any difficulty in detecting the nodal arteries during angiograms?
Do you see the origin and the course?
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These are small caliber arteries and the examination does not necessarily focus on them. Nitroglycerin spayed sublingually can help achieve vasodilatation before angiographic images are taken.
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Shielding design goals are used in the design or evaluation of barriers constructed for the protection of patients, staff and the general public.
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Below is the answer to another question that I gave a while ago, and you should find it helpful:
It is worth adding something to the second part of your question. As you know there are no safe radiation doses (in theory at least). So the objective of shielding is to to ensure that the doses outside the shielded area do not exceed legal limits, or other requirements that may be set nationally. This creates problems in many countries, which do not have their own regulations and tend to follow guidelines available internationally. The most important problem for Engilsh language guidance is that the reccomendations from the US are quite different to those from the EU and the UK. Also, the EC and UK (and many other countries) impose an additional limitation referred to as a Dose Constraint. This is a level used during, for example, the planning of a building to facilitate optimization. Briefly the design levels that tend to be quoted in the US literature are often as high as 50 mSv/y (occupational dose limit). The legal limit often used in EC countries is often as low as 1 mSv/y (public dose limit) and when designing a building this is often reduced further to the design dose constraint of 0.3 mSv/y. All of this is discussed in some detail in the document;
"The Design of Diagnostic Medical Facilities where Ionising Radiation is used."
available for download from my Researchgate page at:
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I'm researching mummies and I am trying to find pathologies for my study. I am not sure whether it is the angle of the x ray causing these 2 circles in the orbit or whether it is an anomaly.
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That one is fun! I am assuming that you are referring to the small foramen indicated at the arrow on the segment of your image that I have attached. The superior circle is the optic foramen and the inferior circle is the medial aspect of the superior orbital fissure.
I noticed that the University of Liverpool has a Medical Imaging and Radiotherapy department within the School of Health Sciences. Their Head is Dr. Stuart Mackay. He may be able to connect you to someone that can help you screen your images.
Carla
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I am doing a mini-systematic review to answer the question 'can cone beam computed tomography improve the risk assessment for inferior nerve injury during lower third molar removal compared to conventional 2d panoramic tomography alone?" My search is limited to studies between 2009 to 2013 March, but my overall finding is that yes cbct is a requisite for the most accurate risk assessment for presurgery treatment planning where an intimate relationship is shown between the inferior alveolar nerve canal and the impacted third molar - does anyone agree/disagree and further questions to be asked?
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I must agree with Prasannasrinivas Deshpande, that most often, numerous radiographic clues can be sought on classical 2D images such as:
- lack of discontinuity of the superior "lamina dura" of the mandibular canal
- good visibility of periapical ligament
- partial superposition of roots and mandibular canal (thus excluding the possibility of have the inferior alveolar nerve completely entrapped between 2 fused roots).
Nevertheless, CBCT imaging proves quite useful in assessing somewhat rare anatomical variations of the mandibular nerve, such as the presence of a retromolar nerve and canal, which can have clinical implications such as difficulty in anesthesia of the retromolar trigone or perioperative bleeding due to surgical trauma of the vascular bundle that accompagnies the retromolar nerve.
For further information:
Lizio G, Pelliccioni GA, Ghigi G, et al. Radiographic assessment of the mandibular retromolar canal using cone-beam computed tomography. Acta Odonto Scand 2013 ;71 :650-655.
Von Arx T, Hänni A, Sendi P et al. Radiographic study of the mandibular retromolar canal : an anatomic structure with clinical importance. J Endod 2011 ;37 :1630-5.
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I have a quick question regarding the recently published Supplements to the "European Guidelines 4th edition". There is a PDF for download here:
I believe that "Table A5.5: Additional g-factors" is wrong. Seems that someone replaced "Breast thickness (cm)" with "Breast thickness (mm)" and multiplied g-factors by 10. Am I right, or am I missing something?
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You are fully correct. The breast thickness is in cm instead of mm and there is a mistake of a factor 10 in the g-factors. I will try to get this rectified/corrected. Thanks for your feedback.
Ruben van Engen
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In those cases, a contrast CT scan seems to be more effective to locate and diagnose the nature of the bleeding. What do you think?
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I do not think that diverticular disease is the only cause of lower gastrointestinal bleeding. In emergancy settings a CT scan may be indicated only after a proctologic examination does not find other source of bleeding (haemorroids, fissures, rectal or anal polyops, solitary ulcer syndrome). Anyway, a successive colonoscopy is mandatory expecially in old patients.
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I'm conducting a study on three groups of subjects, 1 control group (HC) and two different degrees of the same pathology (D1 and D2). I would like to infer the differences of their diffusivity values. I'm using TBSS to do this. I've just compared them, two by two, using unpaired t-tests. Do you suggest to use an ANOVA design before? If yes, which should be the contrast matrix?
I suppose it should be a relatively easy question but I did not find a general agreement about this.
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Yes, of course.
I read on the TBSS forum that "though of course we always try to discourage people
from using ANOVA in general" and I read some instructions on the web but it seems that there is a little bit of confusion about this argument.
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Looking at contrast volumes vs lung volumes - are we getting it right
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Great can we exchange emails to start the process
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Ste wedge
Bone Density in Software like Digora
Cone Beam CT software
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If bone density comes into question from a plain view radiograph, then a follow up, full body dexa scan is ordered (bone density). Follow link for more answers. http://www.osteopenia3.com/dexa-scans.html
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I need to normalize two MR brain volumes in order to match them on a voxel by voxel basis. That means that I need perfect matching between the two brains, i.e. each point of each structure of the first should coincide with the same point (or at least the nearest voxel) of the second. For example the point (x,y) of the thalamus of the first brain should match the same point of the second one.
I tried to use SPM to do this because in the last few years I used it to conduct VBM analyses but I did not obtain an exact correspondence (the reason for which I reflected a lot on this kind of analysis).
Could you please suggest the best way to reach my objective?
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This last comment makes a very important point. Even with the best and most careful registration, you still have no way to confirm that voxels are perfectly matched in a normalized brain space. The other option is to work in native space and create your regions using anatomical boundaries within each individual, which can account for individual differences in anatomy. You can then make strong claims that you are looking at the same brain structure, within a certain degree of confidence based on your inter-rater reliability.
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I have an X-Ray system (fluoroscopic, cinescopy, etc) and I need to calculate the Air-Kerma values (Air-Kerma, Air-Kerma Rate, Dose Area product), and I have to be able to do it utilizing the kVA and mAs values obtained in the system.
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For estimating the air kerma (at a given distance, typically 1 meter) you need the specific yield of the X-ray tube (mGy/mAs). The specific yield depends on the tube voltage and the beam filtration, but also on tube age, construction etc. So the best way is to measure the yield curve of your specific tube, see an example in the attachment. Then you can calculate the air kerma as specific yield * mAs.
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I'm currently comparing the DTI data of three groups of subjects using TBSS.
At first glance I found significant differences among them by performing unpaired t-tests.
After removing two outliers, due to their clinical condition, and using a multiple comparison correction strategy I didn’t find significant differences in two of the comparisons anymore. I therefore tried to compare them without corrections (using a standard threshold) and I found the expected differences again.
Does anyone has the same problem? Do you think it possible to publish uncorrected data if they are reasonable?
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The general rule of thumb is that if you predicted changes in particular areas before you collected the data, you are justified in reporting uncorrected results. But you must explain your a priori hypothesis. If you didn't have any idea where you would see changes appear in the brain, you must use corrected data. For TBSS presentation, a threshold of p<0.05 corrected is considered acceptable.
Tim
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We are thinking of starting to employ the RSNA Mirc system as a teaching file system. Does anybody have any experience they can share? Does it work the way it should, or is a lot of required functionality missing?
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We are at the same point like Peter and his colleagues and evaluate different solutions to get a robust teaching file system up and running.
@Howard: Are there any further resources about the deployment of OsiriX as a teaching file solution?
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There are published data on the indications for referring patients to a CMR study. However, almost all these data have Ben primarily acquired in cardiology environments. So, what are radiologists asked for and what do they think is a valuable question?
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As concerning my hospital, the main questions asked are: tissue characterization and myocardial anatomy/function.