Showing posts with label 3d 360 scanner. Show all posts
Showing posts with label 3d 360 scanner. Show all posts

Thursday, May 8, 2014

What are the best free android apps?




smartypant


I just got an android phone and it's awesome!

I'm just wondering what the best free aops are. I already downloaded angry birds and slice it.



Answer
Tubemate
Adobe reader
mVideoplayer
Winamp
Jigsaroid
Little photo
Color FX
Winamp
MymusicOn
Photo to lab
Magic canvas
Juice defender
Audio tagger free
Ninja jump
Chess free
GPS Test
Photo funia
GPSopt
Battery doctor
Powermax
Skyfire
Opera mini
HD wallpapers
Opera mobile
Penguin fly
Solitaire
3D wallpaper browser
Backgrounds
Appreciate
Cube player
Photo Grid
Appbrain
Navigation
Audiomanager (best for hiding files, also does the function of an real audio manager)
Google skymap
Satellites AR
Super compass
Go EX Launcher
Tag home
Gps essentials
Media converter
CuScreen (fun)
Rmaps
Screen filter
Text to speech SVOX
Free music download
Mixing media player
Network finder
Soul movie
Speedview
BBC News
History eraser
Cover art downloader
Seamen Player
Download all files
Android system info
Magic marker
Photoshop express
FX Camera
livehome
Isodroid
Paint
Barcode scanner
Locus free
CNN
Ulysse Gizmos
Network infoII
Mobo player
tTorrent
Voice search
Taptu
Mortplayer
Facebook
Tricorder
CricketT20fever
Tetris
Free SMS sender
90pandahome2
Free dictionary
Super task manager
Urltopdf
Unrarfree
Android task manager
QQ Player
Droidiris
Advanced task killer
crazyhomelite
Unit converter
dodol wallpaper maker
APNon/off widget
Home switcher
Voice actions
Freecell
Days left
Retro clock
Ghost wars pro
Compass
ESPN
Wikidroid
Yopuzzle2
Baseball superstars
Coveroid
Wallpaper wizardii
Appsfire
Ninja dash
PicsIn
360° camera
G-mon
ultra notes
Pocket
Yellow pages
dxtoplite
Sygic
Auto rotate on/off widget
Rock player
Paper toss
Android assistant
Reversi free
Retro camera
Pyxidis
Free app of today
Ringtone maker


and many many more. Sorry tired off now...




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Saturday, October 26, 2013

tell me the difference :)?

3d 360 scanner
 on 3D    -  ...
3d 360 scanner image



I AM VIETN


Between normal X-ray technology and Computed Tomography used in hospital , especially about Computer Function of CT
thanks
------------------------------------------------------------------------------------------
Small suggestion :)
Are you having blog , could you invite me as your friend :)



Answer
Standard x-rays are simple images similar to photographs taken in the X-ray spectrum of light.

Computed tomography (CT), originally known as computed axial tomography (CAT or CT scan) and body section roentgenography, is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation. The word "tomography" is derived from the Greek tomos (slice) and graphia (to write). CT produces a volume of data which can be manipulated, through a process known as windowing, in order to demonstrate various structures based on their ability to block the X-ray beam. Although historically the images generated were in the axial or transverse plane (orthogonal to the long axis of the body), modern scanners allow this volume of data to be reformatted in various planes or even as volumetric (3D) representations of structures.

Although most common in healthcare, CT is also used in other fields, for example nondestructive materials testing.


Advantages Over Projection Radiography

First, CT completely eliminates the superimposition of images of structures outside the area of interest. Second, because of the inherent high-contrast resolution of CT, differences between tissues that differ in physical density by less than 1% can be distinguished. Third, data from a single CT imaging procedure consisting of either multiple contiguous or one helical scan can be viewed as images in the axial, coronal, or sagittal planes, depending on the diagnostic task. This is referred to as multiplanar reformatted imaging.


Regarding your question about the computing portion, X-ray slice data is generated using an X-ray source that rotates around the object; X-ray sensors are positioned on the opposite side of the circle from the X-ray source. Many data scans are progressively taken as the object is gradually passed through the gantry. They are combined together by the mathematical procedure known as tomographic reconstruction.

Newer machines with faster computer systems and newer software strategies can process not only individual cross sections but continuously changing cross sections as the gantry, with the object to be imaged, is slowly and smoothly slid through the X-ray circle. These are called helical or spiral CT machines. Their computer systems integrate the data of the moving individual slices to generate three dimensional volumetric information (3D-CT scan), in turn viewable from multiple different perspectives on attached CT workstation monitors.
CT scanner with cover removed to show the principle of operation
CT scanner with cover removed to show the principle of operation

In conventional CT machines, an X-ray tube and detector are physically rotated behind a circular shroud (see the image above right); in the electron beam tomography (EBT) the tube is far larger and higher power to support the high temporal resolution. The electron beam is deflected in a hollow funnel shaped vacuum chamber. X-rays are generated when the beam hits the stationary target. The detector is also stationary.

The data stream representing the varying radiographic intensity sensed reaching the detectors on the opposite side of the circle during each sweep is then computer processed to calculate cross-sectional estimations of the radiographic density, expressed in Hounsfield units. Sweeps cover 360 or just over 180 degrees in conventional machines, 220 degrees in EBT.

CT is used in medicine as a diagnostic tool and as a guide for interventional procedures. Sometimes contrast materials such as intravenous iodinated contrast are used. This is useful to highlight structures such as blood vessels that otherwise would be difficult to delineate from their surroundings. Using contrast material can also help to obtain functional information about tissues.

Pixels in an image obtained by CT scanning are displayed in terms of relative radiodensity. The pixel itself is displayed according to the mean attenuation of the tissue(s) that it corresponds to on a scale from -1024 to +3071 on the Hounsfield scale. Pixel is a two dimensional unit based on the matrix size and the field of view. When the CT slice thickness is also factored in, the unit is known as a Voxel, which is a three dimensional unit. The phenomenon that one part of the detector cannot differ between different tissues is called the Partial Volume Effect. That means that a big amount of cartilage and a thin layer of compact bone can cause the same attenuation in a voxel as hyperdense cartilage alone. Water has an attenuation of 0 Hounsfield units (HU) while air is -1000 HU, cancellous bone is typically +400 HU, cranial bone can reach 2000 HU or more (os temporale) and can cause artefacts. The attenuation of metallic implants depends on atomic number of the element used: Titanium usually has an amount of +1000 HU, iron steel can completely extinguish the X-ray and is therefore responsible for well-known line-artifacts in computed tomogrammes.

What laptop would be best?




Miss Sunsh


Hiya, could you help me in finding what laptop would best suit me needs? (University)

First off, i don't need it for games, amazing graphics, or even memory space (I've got a 80gb memory thing which I'll be saving everything to not the laptop in case it crashes.)

What i do need is
1) something that runs really fast and won't leave me waiting ages for pages to load, so a very good working memory. (whatever that is? :P) for instant i use ancestry.co.uk a lot and I'll often have 50+ webpage's pages open at once.
2) Not easily breakable, or prone to glitches. I'm not saying I'm going to throw the thing at the wall, but i don't want some temperamental laptop that keeps crashing or acting up.
3) Somewhat stylish/sleek in appearance.
4) around the £1,000 mark
5) Not a mac, my friend has one and it drives me nuts :P

Any help would be much appreciated. :)
x
Oh and seeing as I'll be getting it for uni/as a uni student, any deals I can cash in on ;o)



Answer
I would recomend the HP G60-214EM. It has one fantastic spec, I have just been looking at laptops and this also has really good deals with it, on pc world. This is a copied spec (from pc world) hope it helps: Processor Type AMD Athlon X2 Dual Core Processor QL62
Processor speed (1.9 GHz, 1 MB Cache) The higher the number of Megahertz (MHZ) the faster the processor should be
Memory Size 3 GB MB
Memory Type DDR2
Hard Drive Capacity 250 GB The bigger the c

Wednesday, October 9, 2013

What is the physics in CAT scan?

3d 360 scanner
 on 3D Scanner Project, Part 2
3d 360 scanner image



sammy


particularly electricity and magnetism (the one who can answer this is really smart) hehehe


Answer
X-ray slice data is generated using an X-ray source that rotates around the object; X-ray sensors are positioned on the opposite side of the circle from the X-ray source. The earliest sensors were scintillation detectors, with photomultiplier tubes excited by (typically) cesium iodide crystals. Cesium iodide was replaced during the eighties by ion chambers containing high pressure Xenon gas. These systems were in turn replaced by scintillation systems based on photo diodes instead of photomultipliers and modern scintillation materials with more desirable characteristics. Many data scans are progressively taken as the object is gradually passed through the gantry. They are combined together by the mathematical procedures known as tomographic reconstruction. The data are arranged in a matrix in memory, and each data point is convolved with its neighbours according with a seed algorithm using Fast Fourier Transform techniques. This dramatically increases the resolution of each Voxel (volume element). Then a process known as Back Projection essentially reverses the acquisition geometry and stores the result in another memory array. This data can then be displayed, photographed, or used as input for further processing, such as multi-planar reconstruction.

Newer machines with faster computer systems and newer software strategies can process not only individual cross sections but continuously changing cross sections as the gantry, with the object to be imaged, is slowly and smoothly slid through the X-ray circle. These are called helical or spiral CT machines. Their computer systems integrate the data of the moving individual slices to generate three dimensional volumetric information (3D-CT scan), in turn viewable from multiple different perspectives on attached CT workstation monitors. This type of data acquisition requires enormous processing power, as the data are arriving in a continuous stream and must be processed in real-time.

In conventional CT machines, an X-ray tube and detector are physically rotated behind a circular shroud (see the image above right); in the electron beam tomography (EBT) the tube is far larger and higher power to support the high temporal resolution. The electron beam is deflected in a hollow funnel shaped vacuum chamber. X-rays are generated when the beam hits the stationary target. The detector is also stationary. This arrangement can result in very fast scans, but is extremely expensive.

The data stream representing the varying radiographic intensity sensed at the detectors on the opposite side of the circle during each sweep is then computer processed to calculate cross-sectional estimations of the radiographic density, expressed in Hounsfield units. Sweeps cover 360 or just over 180 degrees in conventional machines, 220 degrees in EBT.


CT scanner with cover removed to show the principle of operationCT is used in medicine as a diagnostic tool and as a guide for interventional procedures. Sometimes contrast materials such as intravenous iodinated contrast are used. This is useful to highlight structures such as blood vessels that otherwise would be difficult to delineate from their surroundings. Using contrast material can also help to obtain functional information about tissues.

Pixels in an image obtained by CT scanning are displayed in terms of relative radiodensity. The pixel itself is displayed according to the mean attenuation of the tissue(s) that it corresponds to on a scale from +3071 (most attenuating) to -1024 (least attenuating) on the Hounsfield scale. Pixel is a two dimensional unit based on the matrix size and the field of view. When the CT slice thickness is also factored in, the unit is known as a Voxel, which is a three dimensional unit. The phenomenon that one part of the detector cannot differentiate between different tissues is called the "Partial Volume Effect". That means that a big amount of cartilage and a thin layer of compact bone can cause the same attenuation in a voxel as hyperdense cartilage alone. Water has an attenuation of 0 Hounsfield units (HU) while air is -1000 HU, cancellous bone is typically +400 HU, cranial bone can reach 2000 HU or more (os temporale) and can cause artifacts. The attenuation of metallic implants depends on atomic number of the element used: Titanium usually has an amount of +1000 HU, iron steel can completely extinguish the X-ray and is therefore responsible for well-known line-artifacts in computed tomograms. Artifacts are caused by abrupt transitions between low- and high-density materials, which results in data values that exceed the dynamic range of the processing electronics.

Computer Freezes!!!!?




Irfan Burn


My computer always hangs when I tried to use any programs that using 3D features. Including hard games, FLASH games, and even simple games like SOLITAIRE. Sometimes, my computer will hang if I played musics and videos.

I often edit videos and I got annoyed because my computer always hang in the middle of converting process.

I've tried to change my RAM, VGA, power supply cable, adding additional fan inside my computer, and using UPS/Stabilizer. But it's no use.

It's fluxtuation was random. Sometime, i was be able to play games a day full. But the next day, my computer hangs every few seconds after I ran 3D programs.

I'm using Intel Pentium 4;
3.06 GHz Dual Core
1,5 GB of RAM (2 slots)
VGA : ASUS Extreme AX550 series
512.0 MB

What should I do...?



Answer
Your configuration of your computer must be wacky.
The common to your problems is the graphic card

go to the manufacturers website and update the driver.

You can look at this it all helps
Also while your computer is in good nick you should download and install superantispyware because when malware gets going you will not be able to access the net.


Clean Up Computer
===============
Download and run superantispyware. I was put onto this program because of an annoying popup (XP or Vista plus all OS preceding)

http://www.superantispyware.com
Superantispyware is a good program and remember to update it before scanning. A scan may take 45mins.

Note Superantispyware has powerful reset tools that will set stuff back to windows defaults.
To use these tools click preferences >repairs. This may be handy to reset IE URLS if you have annoying pop ups.

Also set up tick boxes that you want in the other tabs as you require.

afterwards clean up the registry with this
Clean up pc and IE
==============
To clean up run this Microsoftâs windows live program. It does registry, spyware , virus , disk clean up and defrag

XP Users http://onecare.live.com/site/en-ca/defau...
http://onecare.live.com/site/en-au/default.htm

Vista Users http://onecare.live.com/site/en-ca/cente...

Run the full safety scanner, it takes a few seconds to install the scanning files but when you start the scan, iIt takes 2 hours or more. So once it starts to load x file of x you can leave the computer and go to bed etc.

Then at the end of the scan it asks you to set it running full time.

Think twice about setting it to run in the background as it could be another thing to slow you down. However, it may be worth while if you have no other security programs running.

Consider the following options:
I personally run Norton 360 which is full internet security and run superantispyware when I want to.

So if you donât have a decent internet security program then perhaps run the superantispyware with your antivirus in the background.

If you sick of antivirus programs that donât work perhaps run onecare full time and run superantispyware whenever.

Now you should be flying and Onecare has even set up a new system restore point for you.

Note onecare does other stuff as well. Click on the menus on the LHS column.

add onecare to your favourites

Slow computer IE freezes
==================
Note: only have to do Safe mode if the files will not delete in normal mode. Try normal first.

Slowly tap the F8 key while the computer is powering up

Just after Verifying DMI files occurs the F8 key will point the computer to a menu where safe mode can be selected.

Note if you mistakenly tap F8 key again, it will continue through to normal boot

Scroll and select safe mode with network

Use explorer to delete the contents of the folder datastore.

Datastore can be found in c:\windows\softwaredistribution.

You may have to do this regularly when the computer slows.

The folder rebuilds itself and the contents are to do with windows updates and logs for errors. There is no harm in deleting the contents.

Reboot.

Also
Over time IE7 seems to set its own (or programs do) tick boxes in the advance tab.
In IE7 (IE6) Tools >Internet Options >Advance Tab
Click Restore advance settings defaults
Tick empty temp files when browser closes (this empties the cache)
Bullet disable phishing filter (IE7)
Delete Browser History, cookies the whole lot regularly.
Close the browser to set the settings.

Optional speed fix
=============
If you want IE7 to speed up and work like IE6 then do this (you can undo it later)
Click tools >manage add ons > enable /disable >select each add on and bullet the disable button
Close the browser to set the settings


RAM and Virtual Memory check
========================
Open up the internet to eg yahoo answers and have a few things open .(eg Word excel or a couple browser pages)
If you normally play music, play that.

Open Task manager >performance tab
Look at the RAM usage in the physical memory (k). If you are using more than 60% of your RAM while your computer is only doing the above then there is not much left for video or games. You may need to install more RAM
1 Gig for XP, 2 Gig for Vista

Look at the PF usage. That is the virtual memory .

Your virtual memory should be set to 1.5 times the amount of RAM you have. Eg 1 gig RAM, therefore 1.5 gig Virtual Memory

Right click my computer icon >properties > advance tab >performance settings > advance tab > virtual memory change > select the drive with the operating system on it (normally C:) bullet custom. Enter the min and max value as one and a half times the RAM you have. In this example, 1500 min and 1500 max. >set.

Your computer is now set for optimum performance for the RAM you have.


Also right click on my computer icon >properties > advance tab >performance settings> the default is let windows, you could try best performance.




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Thursday, September 5, 2013

Computer Freezes!!!!?

3d 360 scanner
 on ct scan left hip 3d ct scan views 2315 keywords
3d 360 scanner image



Irfan Burn


My computer always hangs when I tried to use any programs that using 3D features. Including hard games, FLASH games, and even simple games like SOLITAIRE. Sometimes, my computer will hang if I played musics and videos.

I often edit videos and I got annoyed because my computer always hang in the middle of converting process.

I've tried to change my RAM, VGA, power supply cable, adding additional fan inside my computer, and using UPS/Stabilizer. But it's no use.

It's fluxtuation was random. Sometime, i was be able to play games a day full. But the next day, my computer hangs every few seconds after I ran 3D programs.

I'm using Intel Pentium 4;
3.06 GHz Dual Core
1,5 GB of RAM (2 slots)
VGA : ASUS Extreme AX550 series
512.0 MB

What should I do...?



Answer
Your configuration of your computer must be wacky.
The common to your problems is the graphic card

go to the manufacturers website and update the driver.

You can look at this it all helps
Also while your computer is in good nick you should download and install superantispyware because when malware gets going you will not be able to access the net.


Clean Up Computer
===============
Download and run superantispyware. I was put onto this program because of an annoying popup (XP or Vista plus all OS preceding)

http://www.superantispyware.com
Superantispyware is a good program and remember to update it before scanning. A scan may take 45mins.

Note Superantispyware has powerful reset tools that will set stuff back to windows defaults.
To use these tools click preferences >repairs. This may be handy to reset IE URLS if you have annoying pop ups.

Also set up tick boxes that you want in the other tabs as you require.

afterwards clean up the registry with this
Clean up pc and IE
==============
To clean up run this Microsoftâs windows live program. It does registry, spyware , virus , disk clean up and defrag

XP Users http://onecare.live.com/site/en-ca/defau...
http://onecare.live.com/site/en-au/default.htm

Vista Users http://onecare.live.com/site/en-ca/cente...

Run the full safety scanner, it takes a few seconds to install the scanning files but when you start the scan, iIt takes 2 hours or more. So once it starts to load x file of x you can leave the computer and go to bed etc.

Then at the end of the scan it asks you to set it running full time.

Think twice about setting it to run in the background as it could be another thing to slow you down. However, it may be worth while if you have no other security programs running.

Consider the following options:
I personally run Norton 360 which is full internet security and run superantispyware when I want to.

So if you donât have a decent internet security program then perhaps run the superantispyware with your antivirus in the background.

If you sick of antivirus programs that donât work perhaps run onecare full time and run superantispyware whenever.

Now you should be flying and Onecare has even set up a new system restore point for you.

Note onecare does other stuff as well. Click on the menus on the LHS column.

add onecare to your favourites

Slow computer IE freezes
==================
Note: only have to do Safe mode if the files will not delete in normal mode. Try normal first.

Slowly tap the F8 key while the computer is powering up

Just after Verifying DMI files occurs the F8 key will point the computer to a menu where safe mode can be selected.

Note if you mistakenly tap F8 key again, it will continue through to normal boot

Scroll and select safe mode with network

Use explorer to delete the contents of the folder datastore.

Datastore can be found in c:\windows\softwaredistribution.

You may have to do this regularly when the computer slows.

The folder rebuilds itself and the contents are to do with windows updates and logs for errors. There is no harm in deleting the contents.

Reboot.

Also
Over time IE7 seems to set its own (or programs do) tick boxes in the advance tab.
In IE7 (IE6) Tools >Internet Options >Advance Tab
Click Restore advance settings defaults
Tick empty temp files when browser closes (this empties the cache)
Bullet disable phishing filter (IE7)
Delete Browser History, cookies the whole lot regularly.
Close the browser to set the settings.

Optional speed fix
=============
If you want IE7 to speed up and work like IE6 then do this (you can undo it later)
Click tools >manage add ons > enable /disable >select each add on and bullet the disable button
Close the browser to set the settings


RAM and Virtual Memory check
========================
Open up the internet to eg yahoo answers and have a few things open .(eg Word excel or a couple browser pages)
If you normally play music, play that.

Open Task manager >performance tab
Look at the RAM usage in the physical memory (k). If you are using more than 60% of your RAM while your computer is only doing the above then there is not much left for video or games. You may need to install more RAM
1 Gig for XP, 2 Gig for Vista

Look at the PF usage. That is the virtual memory .

Your virtual memory should be set to 1.5 times the amount of RAM you have. Eg 1 gig RAM, therefore 1.5 gig Virtual Memory

Right click my computer icon >properties > advance tab >performance settings > advance tab > virtual memory change > select the drive with the operating system on it (normally C:) bullet custom. Enter the min and max value as one and a half times the RAM you have. In this example, 1500 min and 1500 max. >set.

Your computer is now set for optimum performance for the RAM you have.


Also right click on my computer icon >properties > advance tab >performance settings> the default is let windows, you could try best performance.

tell me the difference :)?




I AM VIETN


Between normal X-ray technology and Computed Tomography used in hospital , especially about Computer Function of CT
thanks
------------------------------------------------------------------------------------------
Small suggestion :)
Are you having blog , could you invite me as your friend :)



Answer
Standard x-rays are simple images similar to photographs taken in the X-ray spectrum of light.

Computed tomography (CT), originally known as computed axial tomography (CAT or CT scan) and body section roentgenography, is a medical imaging method employing tomography where digital geometry processing is used to generate a three-dimensional image of the internals of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation. The word "tomography" is derived from the Greek tomos (slice) and graphia (to write). CT produces a volume of data which can be manipulated, through a process known as windowing, in order to demonstrate various structures based on their ability to block the X-ray beam. Although historically the images generated were in the axial or transverse plane (orthogonal to the long axis of the body), modern scanners allow this volume of data to be reformatted in various planes or even as volumetric (3D) representations of structures.

Although most common in healthcare, CT is also used in other fields, for example nondestructive materials testing.


Advantages Over Projection Radiography

First, CT completely eliminates the superimposition of images of structures outside the area of interest. Second, because of the inherent high-contrast resolution of CT, differences between tissues that differ in physical density by less than 1% can be distinguished. Third, data from a single CT imaging procedure consisting of either multiple contiguous or one helical scan can be viewed as images in the axial, coronal, or sagittal planes, depending on the diagnostic task. This is referred to as multiplanar reformatted imaging.


Regarding your question about the computing portion, X-ray slice data is generated using an X-ray source that rotates around the object; X-ray sensors are positioned on the opposite side of the circle from the X-ray source. Many data scans are progressively taken as the object is gradually passed through the gantry. They are combined together by the mathematical procedure known as tomographic reconstruction.

Newer machines with faster computer systems and newer software strategies can process not only individual cross sections but continuously changing cross sections as the gantry, with the object to be imaged, is slowly and smoothly slid through the X-ray circle. These are called helical or spiral CT machines. Their computer systems integrate the data of the moving individual slices to generate three dimensional volumetric information (3D-CT scan), in turn viewable from multiple different perspectives on attached CT workstation monitors.
CT scanner with cover removed to show the principle of operation
CT scanner with cover removed to show the principle of operation

In conventional CT machines, an X-ray tube and detector are physically rotated behind a circular shroud (see the image above right); in the electron beam tomography (EBT) the tube is far larger and higher power to support the high temporal resolution. The electron beam is deflected in a hollow funnel shaped vacuum chamber. X-rays are generated when the beam hits the stationary target. The detector is also stationary.

The data stream representing the varying radiographic intensity sensed reaching the detectors on the opposite side of the circle during each sweep is then computer processed to calculate cross-sectional estimations of the radiographic density, expressed in Hounsfield units. Sweeps cover 360 or just over 180 degrees in conventional machines, 220 degrees in EBT.

CT is used in medicine as a diagnostic tool and as a guide for interventional procedures. Sometimes contrast materials such as intravenous iodinated contrast are used. This is useful to highlight structures such as blood vessels that otherwise would be difficult to delineate from their surroundings. Using contrast material can also help to obtain functional information about tissues.

Pixels in an image obtained by CT scanning are displayed in terms of relative radiodensity. The pixel itself is displayed according to the mean attenuation of the tissue(s) that it corresponds to on a scale from -1024 to +3071 on the Hounsfield scale. Pixel is a two dimensional unit based on the matrix size and the field of view. When the CT slice thickness is also factored in, the unit is known as a Voxel, which is a three dimensional unit. The phenomenon that one part of the detector cannot differ between different tissues is called the Partial Volume Effect. That means that a big amount of cartilage and a thin layer of compact bone can cause the same attenuation in a voxel as hyperdense cartilage alone. Water has an attenuation of 0 Hounsfield units (HU) while air is -1000 HU, cancellous bone is typically +400 HU, cranial bone can reach 2000 HU or more (os temporale) and can cause artefacts. The attenuation of metallic implants depends on atomic number of the element used: Titanium usually has an amount of +1000 HU, iron steel can completely extinguish the X-ray and is therefore responsible for well-known line-artifacts in computed tomogrammes.




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