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From: Androcles on 16 Jan 2010 15:13 "Joerg" <invalid(a)invalid.invalid> wrote in message news:7rek2jFd03U2(a)mid.individual.net... > Androcles wrote: >> "Joerg" <invalid(a)invalid.invalid> wrote in message >> news:7rej86Fd03U1(a)mid.individual.net... >>> Androcles wrote: >>>> "RichD" <r_delaney2001(a)yahoo.com> wrote in message >>>> news:524e9de7-330d-40fd-90f5-0d671ec9ce7d(a)j19g2000yqk.googlegroups.com... >>>>> is it possible to design a subcutaneous x ray? >>>>> A surgeon might want to see a depth just below >>>>> where he intends to cut. >>>>> >>>>> The point is, I thought only bones are opaque to x rays. >>>> The problem is focus. >>>> Hold a page of text up at normal reading distance and focus on a few >>>> words. Note that background and peripheral objects, although >>>> noticeable, are out of focus. Now focus on a background object and note >>>> that the writing on the paper is no longer in focus. All lenses, >>>> including those in your eyes, have limited distances or ranges in which >>>> two objects on different planes (focal planes) may be simultaneously in >>>> focus. >>>> The solution has been MRI. >>>> >>> Ultrasound machine had dynamic focusing since the 70's :-) >>> >>> What this means is "on-the-fly" focusing, like a lens that bends to the >>> correct shape while the echoes are coming back from deeper and deeper >>> regions. Easy on receive, but for transmit you need to do several shots >>> and stitch the resulting horizontal image slices together. That's a >>> whole science unto itself but nowadays very much standard procedure. >> >> Yes, I wouldn't doubt it. I have no medical degree and very little >> knowledge in that field, my only use of ultrasound has been >> in an electronics cleaning bath. My experience with MRI is a >> yearly check up when I'm injected with something that makes me >> feel hot and want to pee! >> Thanks for the info. >> > > Yearly? Wow! I was never in an MRI, so far. One reason why ultrasound is > preferred is that MRI is hugely expensive while an ultrasound scan is > typically reimbursed at the two-digit Dollar level. MRI is usually > four-digit. > > The underlying reason is equipment cost. A good MRI machine costs millions > while a decent ultrasound scanner can be had for under $50k. > I have had a stent in my aorta since 2007. I suppose it is worth 4 digits to make sure it hasn't moved, it cost enough to put it there. http://www.web-books.com/eLibrary/Medicine/Cardiovascular/Images/aneurysm_aortic.jpg http://cvm.msu.edu/hospital/services/interventional-radiology/ir-media/Tracheal%20Stent.jpg
From: Androcles on 16 Jan 2010 15:25 "Phil Hobbs" <pcdhSpamMeSenseless(a)electrooptical.net> wrote in message news:-cCdnbu8Ts-Egc_WnZ2dnUVZ_tSdnZ2d(a)supernews.com... > On 1/16/2010 5:31 AM, Androcles wrote: >> "RichD"<r_delaney2001(a)yahoo.com> wrote in message >> news:524e9de7-330d-40fd-90f5-0d671ec9ce7d(a)j19g2000yqk.googlegroups.com... >>> is it possible to design a subcutaneous x ray? >>> A surgeon might want to see a depth just below >>> where he intends to cut. >>> >>> The point is, I thought only bones are opaque to x rays. >> >> The problem is focus. >> Hold a page of text up at normal reading distance and focus on a few >> words. >> Note that background and peripheral objects, although noticeable, are out >> of >> focus. Now focus on a background object and note that the writing on the >> paper is no longer in focus. All lenses, including those in your eyes, >> have >> limited distances or ranges in which two objects on different planes >> (focal >> planes) may be simultaneously in focus. >> The solution has been MRI. >> >> > There are lots of solutions to this. In optical microscopy, you can take > images at several depths and combine them, choosing the level that shows > the most contrast at each position. Zeiss has been selling systems like > that for years. > > In confocal microscopy(*), you can just sum the images taken from > different depths, since out-of-focus planes hardly contribute to the image > at all. > > There's also phase-coded imaging, which uses an artistically designed > phase plate to allow 3D reconstruction from a single image. (It's really > a beautiful technique, which I'd like to understand better than I do.) > > So the old classical optics limitations are being overcome all over the > place. > > Cheers > > Phil Hobbs > > (*)My thesis was on a phase sensitive laser scanning confocal microscope, > and I helped invent the modern real-time confocal. > > -- > Dr Philip C D Hobbs > Principal > ElectroOptical Innovations > 55 Orchard Rd > Briarcliff Manor NY 10510 > 845-480-2058 > > email: hobbs at electrooptical dot net > http://electrooptical.net Very interesting, but Delaney's original question regarded x-rays on subcutaneous tissue, not optical light on a slide. This suggests ... well, you work it out; it may be worth a patent, although dental x-rays seem to be adequate if the film is close to the tooth.
From: Joerg on 16 Jan 2010 15:42 Androcles wrote: > "Joerg" <invalid(a)invalid.invalid> wrote in message > news:7rek2jFd03U2(a)mid.individual.net... >> Androcles wrote: >>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>> news:7rej86Fd03U1(a)mid.individual.net... >>>> Androcles wrote: >>>>> "RichD" <r_delaney2001(a)yahoo.com> wrote in message >>>>> news:524e9de7-330d-40fd-90f5-0d671ec9ce7d(a)j19g2000yqk.googlegroups.com... >>>>>> is it possible to design a subcutaneous x ray? >>>>>> A surgeon might want to see a depth just below >>>>>> where he intends to cut. >>>>>> >>>>>> The point is, I thought only bones are opaque to x rays. >>>>> The problem is focus. >>>>> Hold a page of text up at normal reading distance and focus on a few >>>>> words. Note that background and peripheral objects, although >>>>> noticeable, are out of focus. Now focus on a background object and note >>>>> that the writing on the paper is no longer in focus. All lenses, >>>>> including those in your eyes, have limited distances or ranges in which >>>>> two objects on different planes (focal planes) may be simultaneously in >>>>> focus. >>>>> The solution has been MRI. >>>>> >>>> Ultrasound machine had dynamic focusing since the 70's :-) >>>> >>>> What this means is "on-the-fly" focusing, like a lens that bends to the >>>> correct shape while the echoes are coming back from deeper and deeper >>>> regions. Easy on receive, but for transmit you need to do several shots >>>> and stitch the resulting horizontal image slices together. That's a >>>> whole science unto itself but nowadays very much standard procedure. >>> Yes, I wouldn't doubt it. I have no medical degree and very little >>> knowledge in that field, my only use of ultrasound has been >>> in an electronics cleaning bath. My experience with MRI is a >>> yearly check up when I'm injected with something that makes me >>> feel hot and want to pee! >>> Thanks for the info. >>> >> Yearly? Wow! I was never in an MRI, so far. One reason why ultrasound is >> preferred is that MRI is hugely expensive while an ultrasound scan is >> typically reimbursed at the two-digit Dollar level. MRI is usually >> four-digit. >> >> The underlying reason is equipment cost. A good MRI machine costs millions >> while a decent ultrasound scanner can be had for under $50k. >> > I have had a stent in my aorta since 2007. > I suppose it is worth 4 digits to make sure it hasn't moved, it cost enough > to put it there. > > http://www.web-books.com/eLibrary/Medicine/Cardiovascular/Images/aneurysm_aortic.jpg > http://cvm.msu.edu/hospital/services/interventional-radiology/ir-media/Tracheal%20Stent.jpg > Oh yeah, got to be careful. Glad that they caught yours in time since aortic aneurysms are generally symptom-less. With a friend of ours it happened on a golf course, too late :-( -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Androcles on 16 Jan 2010 15:56 "Joerg" <invalid(a)invalid.invalid> wrote in message news:7remmlFu8dU3(a)mid.individual.net... > Androcles wrote: >> "Joerg" <invalid(a)invalid.invalid> wrote in message >> news:7rek2jFd03U2(a)mid.individual.net... >>> Androcles wrote: >>>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>>> news:7rej86Fd03U1(a)mid.individual.net... >>>>> Androcles wrote: >>>>>> "RichD" <r_delaney2001(a)yahoo.com> wrote in message >>>>>> news:524e9de7-330d-40fd-90f5-0d671ec9ce7d(a)j19g2000yqk.googlegroups.com... >>>>>>> is it possible to design a subcutaneous x ray? >>>>>>> A surgeon might want to see a depth just below >>>>>>> where he intends to cut. >>>>>>> >>>>>>> The point is, I thought only bones are opaque to x rays. >>>>>> The problem is focus. >>>>>> Hold a page of text up at normal reading distance and focus on a few >>>>>> words. Note that background and peripheral objects, although >>>>>> noticeable, are out of focus. Now focus on a background object and >>>>>> note that the writing on the paper is no longer in focus. All lenses, >>>>>> including those in your eyes, have limited distances or ranges in >>>>>> which two objects on different planes (focal planes) may be >>>>>> simultaneously in focus. >>>>>> The solution has been MRI. >>>>>> >>>>> Ultrasound machine had dynamic focusing since the 70's :-) >>>>> >>>>> What this means is "on-the-fly" focusing, like a lens that bends to >>>>> the correct shape while the echoes are coming back from deeper and >>>>> deeper regions. Easy on receive, but for transmit you need to do >>>>> several shots and stitch the resulting horizontal image slices >>>>> together. That's a whole science unto itself but nowadays very much >>>>> standard procedure. >>>> Yes, I wouldn't doubt it. I have no medical degree and very little >>>> knowledge in that field, my only use of ultrasound has been >>>> in an electronics cleaning bath. My experience with MRI is a >>>> yearly check up when I'm injected with something that makes me >>>> feel hot and want to pee! >>>> Thanks for the info. >>>> >>> Yearly? Wow! I was never in an MRI, so far. One reason why ultrasound is >>> preferred is that MRI is hugely expensive while an ultrasound scan is >>> typically reimbursed at the two-digit Dollar level. MRI is usually >>> four-digit. >>> >>> The underlying reason is equipment cost. A good MRI machine costs >>> millions while a decent ultrasound scanner can be had for under $50k. >>> >> I have had a stent in my aorta since 2007. >> I suppose it is worth 4 digits to make sure it hasn't moved, it cost >> enough to put it there. >> >> >> http://www.web-books.com/eLibrary/Medicine/Cardiovascular/Images/aneurysm_aortic.jpg >> >> http://cvm.msu.edu/hospital/services/interventional-radiology/ir-media/Tracheal%20Stent.jpg >> > > Oh yeah, got to be careful. Glad that they caught yours in time since > aortic aneurysms are generally symptom-less. With a friend of ours it > happened on a golf course, too late :-( > If sudden intense back pain while sitting relaxed at the computer is symptom-less then I would hate to find out what a symptom is. :-) I went to lay on the bed but it wasn't easing after 30 minutes so I called an ambulance. At least I finished the post I was writing.
From: Joerg on 16 Jan 2010 16:31
Androcles wrote: > "Joerg" <invalid(a)invalid.invalid> wrote in message > news:7remmlFu8dU3(a)mid.individual.net... >> Androcles wrote: >>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>> news:7rek2jFd03U2(a)mid.individual.net... >>>> Androcles wrote: >>>>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>>>> news:7rej86Fd03U1(a)mid.individual.net... >>>>>> Androcles wrote: >>>>>>> "RichD" <r_delaney2001(a)yahoo.com> wrote in message >>>>>>> news:524e9de7-330d-40fd-90f5-0d671ec9ce7d(a)j19g2000yqk.googlegroups.com... >>>>>>>> is it possible to design a subcutaneous x ray? >>>>>>>> A surgeon might want to see a depth just below >>>>>>>> where he intends to cut. >>>>>>>> >>>>>>>> The point is, I thought only bones are opaque to x rays. >>>>>>> The problem is focus. >>>>>>> Hold a page of text up at normal reading distance and focus on a few >>>>>>> words. Note that background and peripheral objects, although >>>>>>> noticeable, are out of focus. Now focus on a background object and >>>>>>> note that the writing on the paper is no longer in focus. All lenses, >>>>>>> including those in your eyes, have limited distances or ranges in >>>>>>> which two objects on different planes (focal planes) may be >>>>>>> simultaneously in focus. >>>>>>> The solution has been MRI. >>>>>>> >>>>>> Ultrasound machine had dynamic focusing since the 70's :-) >>>>>> >>>>>> What this means is "on-the-fly" focusing, like a lens that bends to >>>>>> the correct shape while the echoes are coming back from deeper and >>>>>> deeper regions. Easy on receive, but for transmit you need to do >>>>>> several shots and stitch the resulting horizontal image slices >>>>>> together. That's a whole science unto itself but nowadays very much >>>>>> standard procedure. >>>>> Yes, I wouldn't doubt it. I have no medical degree and very little >>>>> knowledge in that field, my only use of ultrasound has been >>>>> in an electronics cleaning bath. My experience with MRI is a >>>>> yearly check up when I'm injected with something that makes me >>>>> feel hot and want to pee! >>>>> Thanks for the info. >>>>> >>>> Yearly? Wow! I was never in an MRI, so far. One reason why ultrasound is >>>> preferred is that MRI is hugely expensive while an ultrasound scan is >>>> typically reimbursed at the two-digit Dollar level. MRI is usually >>>> four-digit. >>>> >>>> The underlying reason is equipment cost. A good MRI machine costs >>>> millions while a decent ultrasound scanner can be had for under $50k. >>>> >>> I have had a stent in my aorta since 2007. >>> I suppose it is worth 4 digits to make sure it hasn't moved, it cost >>> enough to put it there. >>> >>> >>> http://www.web-books.com/eLibrary/Medicine/Cardiovascular/Images/aneurysm_aortic.jpg >>> >>> http://cvm.msu.edu/hospital/services/interventional-radiology/ir-media/Tracheal%20Stent.jpg >>> >> Oh yeah, got to be careful. Glad that they caught yours in time since >> aortic aneurysms are generally symptom-less. With a friend of ours it >> happened on a golf course, too late :-( >> > > If sudden intense back pain while sitting relaxed at the computer is > symptom-less then I would hate to find out what a symptom is. :-) Problem is, that many people (like myself) have those shooting back pains come up for the usual reasons. "Floppy disks", as some folks in the south would say ... > I went to lay on the bed but it wasn't easing after 30 minutes so I > called an ambulance. At least I finished the post I was writing. > You were very lucky. Our friend was calmly standing there looking at a golf shot someone did. Then he just fell over, and that was it. Another friend had one in brain blood vessels but she survived. She said she felt absolutely nothing, just blacked out. Luckily they had a meeting and the guy next to her caught her head before it hit the table and another dialed 911 milliseconds later. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. |