Imaging Definition and 155 Threads

Homework Statement (1) An ideal digital detector only suffers from quantum noise. If, after being exposed to 5 µGy the mean pixel value in the image is 100 and the standard deviation of the pixel values in the image is 5, calculate the SNR? The relationship between pixel value and detector...

Hi, my lecturer said that in PET imaging, the image resolution is superior when the E(max) of the positrons is lower. Why should this be? Thanks

Hello, I just was looking for possible information in the field of imaging quality assurance. I was wondering if their were any predominant scripts or papers on the subject of detecting the quality of an image. I know measuring how "good" an image is incredibly qualitative however, there are...

I observed following phenomena today: in my room with some lightings, there is a stuff toy placed in front of a wall. The ambient lighting doesn't cause any shadow on the wall currently. Now, I switched ON a torch and pointed it to a stuff toy which was kept in front of a wall and a shadow...

Hello, I am wondering if the boards can reccomend any topics of medical imaging in healthcare. I have to make a presentation on the topic and write a paper. The paper must only be sourced from peer reviewed articles or government statistics. So it should be realitvely well known. I believe...

I am a sophomore at RIT studying imaging science, which is essentially a major dedicated to the engineering and development of imaging technologies. i.e. MRIs, lasers, telescopes---anything that involves light. I love my major and plan to use it to pursue a career in astronomy and planetary...

Are there any studies or resources related to imaging of the optic nerve when participants are exposed to specific images or colors? I can't seem to find anything relating to this topic, but I think it would be interesting.

Is it possible to rig a Truss Dobsonian telescope like this one so that you can control it remotely from inside of a building while the telescope itself is on the roof of the building? Then is it possible to attach some sort of adapter to the telescope that would allow you to hook up a camera...

What is meant by a negative distance on a sinogram in PET imaging? http://frcrphysics.com/wp-content/uploads/2014/05/PET-sinogram.jpg In this image displacement can be +ve or -ve. What would a -ve distance be? Thanks

I should start by saying that, as a novice data analyst, I have very little experience with MRI physics, but I believe I understand the absolute fundamentals. Also, this post mostly concerns data analysis issues so might be better suited for some other signal processing forum, but I'm hoping...

Hi everyone. I am currently involved in a project which is using UWB technology to sense/localise/image objects behind walls. The requirement is not to have any transceivers in the room that is going to be imaged. Currently, the idea I have is to detect the backscatter UWB pulses reflected from...

do you have imaging processing' document in matlab? can you share with me? Do you have code MATLAB about increase form yellow to red? Thanks your attention

Looking at Ben Krasnow's youtube video on breaking down the parts and general cost for a scanning electron microscope, he lists a raster scan generator, is that able to produce the highest resolution images still? Or is there another more modern technology for this purpose? Otherwise, how has...

Hi there, I am having a lot of struggles with program. I am not using this for any true kind of publication but more so we can reference material. However, it is very important that I have a coordinate system where I can plot the WCS. Whenever I try to save as a PNG or JPEG it does not...

Hi! Assume paraxial rays. If I have a lens with a focal length ##f## and I place an object at the focal length to the left of the lens, the image will be at infinity. Correct? But will it be imaged in infinity to the left or right of the lens? If I am looking into the lens from the right I...

Hi pf, Please could someone kindly answer a few questions about proton spin in the context of MRI. As I understand it when an external static magnetic field is applied to a patient the magnetic dipole moments of the protons in the hydrogen nuclei will experience a torque causing them to align...

The fundamental question, what is the reference geometry where images can be fused to form a 3D panorama? In other words, how images are assigned a 3D position? Does it require a gyroscope to be built in camera to define its position per image of the interest? Or just it simply fuses images with...

I have a PhD in medical physics from the MD Anderson CAMPEP program and I even took ABR step 1 (just prior to the cut off for residency requirements). Are there any imaging physicists here? Woudl really like to get your feedback on the current outlook for diagphys careers. I have not been having...

I am trying to model a simple system, but the ray-tracing does not seem to be consistent with the analysis of the system in terms of Seidel aberration values. Here's the system layout: When the system contains only the Eye model and the OL lens, it can be referred from the Seidel diagram that...

Hello, I have heard many times that red lighting is good for imaging applications where the effect of ambient light needs to be reduced to a minimum. What is the theory behind this? Why does red light (vs. other colors) reduce the effect of ambient light? Thank you.

Greetings, After getting some training I have access to my universities SEM facilities and I would like to image CDs and DVDs with it(, I know that these consist of many layer which may not be transparent to the e-beam so they might need some preparation. Does anyone have any idea? I am...

I have a question concerning the paper "Quantum imaging with undetected photons". http://arxiv.org/abs/1401.4318 In the schematic (Fig. 1) a photon (idler) is created at NL1 and passing the object at O to be reflected further to NL2. It is then stated in the paper "By reflection at dichroic...

Homework Statement Use either image charge method of separation of variables to solve: The distance between two large, grounded parallel conducting plates is 4x. Between them, two point charges +Q and -Q are inserted and have a distance x and 3x from one of the plates. (A line connecting the...

Hello all, I have been looking at the arXiv account of the quantum imaging experiment but there are certain features of the theory I am trying to get a better understanding of. The main thing at the moment is the relationship between the signal and idler photons. Consider those idlers that are...

Assuming that the double slit experiment creates interference patterns when electrons interact with themselves (or 'other' selves) from a parallel 'space' - one wonders if one can 'image', or at least gain more information about that other 'space' (dare I use the word 'dimension'?) in which the...

I was recently taught that the probability of the photoelectric effect occurring was proportional to Z^3 and E^-3 (where Z is the atomic number, and E is the energy of the photon). My understanding is that the photon's energy must be close to the binding energy of the inner electron to be...

In several fiber-optic-based probes in medical imaging fields, the light travels towards an object through an optical fiber (or even free space), interacts with the object and then travels back through the same fiber (or the same path in free space) and is captured by a camera or photodetector...

To the best of my knowledge, thermal imaging (with a thermograph as the end results) is performed using arrays of thermopiles. This can become hugely expensive and is the reason fire services sometimes have trouble affording thermal imaging cameras. Snakes have heat sensitive ion channels...

Hello, Schrödinger's Picture: Researchers Take An Image Without Ever Detecting Light which speaks about the article from nature Quantum imaging with undetected photons" Normally by the entangled it is not possible to transfer information :rolleyes: Patrick

Could anyone please explain or advice me where to read about principles of Schlieren image formation NOT in terms of ray optics, but in terms of wave or Fourier optics. I understand how that works in terms of heuristic ray optics, but would like to get to know how the actual image formation...

I have a Fresnel lens which is equal-ant to a Plano Convex lens, Consider object on one side and my eye is on the other side of the lens, when I see through that lens I always do see an upright image of same size even if I flip the lens, Can anyone please tell me geometric optics equal-ant of...

Homework Statement Imagine a 10 cm thick slab of flesh. If your x-ray imager can reliably identify a 5% change in intensity from one location to another in an image, what is the smallest diameter bone you are going to be able to make detect in your x-ray image? Absorption length of bone...

In pseudo-thermal ghost imaging using a laser beam passing through a rotating ground glass plate, the temporal coherence is important since the intensities in both scanning and bucket detectors have to be measured within the coherence time of the beam. However, in computational ghost imaging...

Hi there, I've been trying to solve this problem regarding relay imaging so that I can modify my experimental setup accordingly. Please refer to the attached jpg file for the lens setup. I am trying to image the object (the purple block in the attached jpg file) at a specific imaging plane...

hi, i have to prepare a presentation about rf imaging. But i didn't found any medical imaging system using rf. Is there anyone know commercial rf medical imaging system, please help me.

How do particle colliders read the trajectories of particles in the collider? Are EM waves emitted from each of the particles? If some particles do not emit EM waves, does the "sensor" only read particles that emit EM waves? ...In other words, what bridges the gap between our pictorial data and...

Hello people, first i need to say that i am quite a newb for astronomy. I have a idea about creating deep space stereoscopic images. I was wondered if it is usable to place two satellites(space telescopes) in heliocentric orbit, with distance approximately that of pluto , that are 180...

Hi, I'm new to this forum and I have an application where I want to image an object that is in contact with the round side of a half ball lens. I've attached a brief project description. I think this topic on optics is suitable for the Differential Geometry forum, but please let me know if...

Forum, I am an engineering student from Melbourne Australia and I have a simple question related to a literature research project I'm currently undertaking, hopefully someone can help me out. Which engineering or safety standards would a design for a CT or fluoroscopy system, more...

From what I understand, ultrasound beams are generated from hundreds of piezo crystals that constructively interfere with one another. When the beam is reflected, it returns to the crystals and the crystal directly above the reflection (the crystal that obtains mechanical vibrations) records the...

MRIs are used in medicine for diagnostic imaging. I am told it has something to do with protons. But in the human body protons don't exist, only occasional hydronium ions (H3O+. ) I am told that a strong magnetic field imparts a "spin" to the protons (I don't know if this in a quantum...

Dear all, I have a quick question about the use of coupling gel in ultrasound imaging (of an unborn child as an example). As I understand it, if coupling gel were not used, as the ultrasound waves left the transducer, they would undergo a massive amount of reflection at the air-skin (body...

Hello, I use a 10x infinity objective as a condenser in a optical trap setup. The collimated forward scattered light is then focused with a 40mm lens onto a QPD. This is the imaging techqnique. There is also BFPI, and I am not clear on this method. My understanding is that I need to image the...

So I'm an EE undergrad student and the design of medical imaging devices is one area I'm interested in. I often hear that's more appropriate for a BME major. However, designing medial imaging devices undoubtedly involves a lot of knowledge in electronics design, signal processing...

I have a question about observing a field of radiated light (and it's source) through a microscope, specifically vis magnification and the scale of the final image observed (the field, and also the source). I have a slice of field intensity at the plane of a microscope's numerical aperture...

I'm graduating this year with a master in nuclear physics. In my bachelors I did a minor in medical radiation physics. This way I was introduced to medical imaging and I decided to take elective courses from the postgraduate advanced medical imaging. If I hadn't chosen my thesistopic then, I...

The TRACE website has a solar image that is described as, quoting from the text associated with the image, "This is a false-color, 3-layer composite from the TRACE observatory showing the solar corona: the blue, green, and red channels show the 171A, 195A, and 284A, respectively. These TRACE...

Is it possible to detect exoplanets with amateur telescopes? If so what size would be needed. I have seen some amateur protoplanetary disks pictures and would one be able to tell if an exoplanet existed in it as I carved out the material for planet formation? Is it possible for us with current...

This is my first attempt at imaging a debris disk around a star. I chose Fomalhaut because, as far as I can tell, there are no other stars visible at this time of year in the northern hemisphere with their disk's as widely separated from them as Fomalhaut. This task is rather difficult...

Dewing of a mirror or object glass can be countered with various devices and methods, but its occurrence inside a closed system is particularly problematic. I have received the following enquiry (from an experienced observer who has used several instruments over many years) concerning...