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Medicine Technology

Some Hospitals Are Ditching Lead Aprons During X-Rays 104

Posted by BeauHD from the about-face dept.
pgmrdlm shares a report from ABC News: Some hospitals are ditching the ritual of covering reproductive organs and fetuses during imaging exams after prominent medical and scientific groups have said it's a feel-good measure that can impair the quality of diagnostic tests and sometimes inadvertently increase a patient's radiation exposure. The about-face is intended to improve care, but it will require a major effort to reassure regulators, health care workers and the public that it's better not to shield.

Lead shields are difficult to position accurately, so they often miss the target area they are supposed to protect. Even when in the right place, they can inadvertently obscure areas of the body a doctor needs to see -- the location of a swallowed object, say -- resulting in a need to repeat the imaging process, according to the American Association of Physicists in Medicine, which represents physicists who work in hospitals. Shields can also cause automatic exposure controls on an X-ray machine to increase radiation to all parts of the body being examined in an effort to "see through" the lead. Moreover, shielding doesn't protect against the greatest radiation effect: "scatter," which occurs when radiation ricochets inside the body, including under the shield, and eventually deposits its energy in tissues. "In April, the physicists' association recommended that shielding of patients be 'discontinued as routine practice,'" the report adds. "Its statement was endorsed by several groups, including the American College of Radiology and the Image Gently Alliance, which promotes safe pediatric imaging. However, experts continue to recommend that health care workers in the imaging area protect themselves with leaded barriers as a matter of occupational safety."
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Some Hospitals Are Ditching Lead Aprons During X-Rays More

Some Hospitals Are Ditching Lead Aprons During X-Rays

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  • X-Ray machines (Score:3)

    by Arthur, KBE ( 6444066 ) on Thursday January 16, 2020 @10:33PM (#59628458)
    The beams are pretty focused and most of the aprons are just tossed onto the patient and droop or fit sloppily.

    • Re:X-Ray machines (Score:5, Informative)

      by Tim Hamilton ( 5961502 ) on Thursday January 16, 2020 @10:55PM (#59628486)
      Holy cow, BeauHD, you high school imbecile! How dare you attempt to mislead people on a once-reputable technology news site!

      Lead shields are difficult to position accurately, so they often miss the target area they are supposed to protect. Even when in the right place, they can inadvertently obscure areas of the body a doctor needs to see -- the location of a swallowed object, say -- resulting in a need to repeat the imaging process, according to the American Association of Physicists in Medicine, which represents physicists who work in hospitals. Shields can also cause automatic exposure controls on an X-ray machine to increase radiation to all parts of the body being examined in an effort to "see through" the lead. Moreover, shielding doesn't protect against the greatest radiation effect: "scatter," which occurs when radiation ricochets inside the body, including under the shield, and eventually deposits its energy in tissues.

      Any idiot radiologist knows that X-rays are an optics problem which is what ALL the above "arguments" for removing shielding display ignorance of. If the operator does not understand reflection of radiation, absorption, or how the equipment even works ('in an effort to "see through" the lead'), these persons should have their credentials and licenses revoked

      And as for you, Arthur, yes, that is the idea for the aprons to be "sloppy." Statistically, they don't do a *huge* amount, and they are important enough to wear, but they are not important enough to affix them with something constrictive like a straitjacket. I am in the medical field, and my wife is an endodontist with a bachelor's and master's degree in physics. She "swears by" the apron for the patient as being worthwhile and always walks behind a dense wall whenever she runs the CBCT. That 0.5% lower chance of cancer X is worth a few footsteps for everyone.

      • And I'm a big highfalutin PhD nuclear podiatrist and Knight of the British Empire. So there.

      • Re: (Score:2, Insightful)

        by Anonymous Coward

        Holy cow, BeauHD, you high school imbecile!

        Tim,
        Can I call you Tim? No? OK.
        Asshole,
        Grow the fuck up. Why did write that ? It's clear that a) It's a quote, so b) It's not necessarily BeauHD's opinion, and c) Based on the story, there is legitimate debate in the medical community about the efficacy of shielding.

        If you'd like to participate in that debate, you might try modeling your input on posts like this one [slashdot.org], wherein someone describes some legitimate reasons that lead aprons might cause problems. Note t

      • Re: (Score:1, Informative)

        by Anonymous Coward

        This decision is based on solid scientific evidence. The only "optics" problem is in the political sense; a single X-ray exposure is completely benign. Even a CT scan won't come close to increasing chances of cancer by 0.5%. Low dose radiation is not harmful; on the contrary, it has even been shown effective in treating cancer [cureus.com]. Many people would be healthier and alive today if not for decades of FUD causing avoidance of imaging and limiting research into medical applications.

        Further reading:
        Radiation Hormes [nih.gov]

        • Re: (Score:1)

          by Anonymous Coward
          Radiation-based hormesis is a bunch of pseudoscience. Cherry-pick the sample set, and sure, you get life extension. Look at a real sample set, and yeah, you have vaporized DNA and killed cells.

      • Re:X-Ray machines (Score:4, Funny)

        by quenda ( 644621 ) on Friday January 17, 2020 @01:15AM (#59628660)

        Holy cow, BeauHD, you high school imbecile! >

        Hi, you must be new here. Welcome to slashdot.

      • What I get from their statement is this: "Lead aprons are not being used properly, so obviously the solution is not to use them at all."

        They also don't even mention dental X-rays or dental CT scans.

        I'm also a bit suspicious of "American Association of Physicists in Medicine": presumably they know about physics, but how much do they know about physiology? (They do quote from the American College of Obstetricians and Gynecologists.)

    • Exactly right. X-ray techs can't be bothered to do it right, so why bother doing it. Who cares if there are 100,000 more cancers in a population of 400,000,000. It's just a drop in the bucket.

  • Seriously? (Score:5, Insightful)

    by pz ( 113803 ) on Thursday January 16, 2020 @10:41PM (#59628476) Journal

    Reading through the summary one comes to the conclusions that ...

    1. There are hospitals that find their technicians mis-position lead aprons so frequently that they are increasing exposure to a fraction of patients that is MORE damaging than removing basic protection and thus increasing exposure for everyone. Me, I'll stay away from those hospitals, thanks, since their hiring procedures appear to be seriously lacking.

    2. Lead shields help, even if they are not perfect (i.e., they don't help with internal scatter). So, despite the fact that they are beneficial, because they are not perfect, we shouldn't use them at all. Right. Again, I'll stay away from hospitals that rely on reasoning like that.

    3. Risk from radiation is sufficiently large that employees who are substantially removed from the radiation source in 1/r^2 terms should be shielded, but patients don't need to worry? Right. I'll definitely be going to other hospitals, thanks.

    • Re: (Score:3)

      by Cyberax ( 705495 )
      The main issue is that they are pointless. The additional whole-body radiation exposure from typical x-ray is immaterial. With the LNT model you would expect an additional cancer every several tens of millions of exposures. So lead aprons are basically just "feel good" measures anyway.

    • Re:Seriously? (Score:5, Insightful)

      by drkshadow ( 6277460 ) on Thursday January 16, 2020 @11:14PM (#59628532)

      Egad, man!

      I've noticed at dentist offices that the newer ones say "Our equipment is new; the new stuff uses better technology and weaker X-ray sources, so you just don't need pratective coverings." They barely step around the corner, not taking any extra precautions themselves. I believe that second part: newer technology, sources of energy less intense.

      So lets address your risk 3. The last time I had a chest X-ray, the machine was about five feet from me. It irradiated my upper torso, presumably. The X-ray practitioner was about ten feet away, behind, presumably, a wall with leaded glass (and some sort of lead insulation within?). They're standing to the side, not behind; gotta keep an eye on the patient.

      Perhaps the scatter does dissipate with 1/r^2. (Surely you're not suggesting the X-ray machine completely lacks focus.) Suppose that the X-rays hit the body, scatters and goes 3 feet through your body, on average. (It's an x-ray. It goes completely through it -- your body scarcely appears in the image.) Then, they're receiving 1/3^2 as much radiation as your body (which isn't 3ft thick in all directions): it goes 3ft through your body, they're 8-10ft away -- they're 3x as far away, take the inverse of the square of the proportional distance. So, yeah, they're getting 1/9th the radiation that you are. Ok.

      Then they're taking X-rays every 20 minutes. So, 3*8hr, 24x the exposure per day. 300 working days per year? Do the math. Really.

      Basic occupational safety. Check.

      You stick with the older tech, though: the machines that probably justify the lead vest, don't use as focused an energy source, just blast the whole area with X-rays until the film shows some bone. No computer noise reduction, no reduced dosages, no modern technology. That's allllll you.

      • Re: (Score:2)

        by rastos1 ( 601318 )
        His argument wasn't that operators should not be shielded, but that patients should be shielded too (on parts that are not relevant to the diagnostics).

      • Re: (Score:2)

        by Bengie ( 1121981 )
        "Step around the corner"? They use hand held x-rays guns now. They can't step away from it, they hold it in their hand. Heck, my wife recently had some injections put into her hand where they had a real-time x-ray video so the nurse could get the needle exactly perfect to improve the quality. They're both sitting next to a device that is just constantly emitting x-rays, for several minutes.
      • I recall my former dentists office. They told me that it was hard to manipulate the x-ray head after it'd been used for some time. I explained heat - you know it is a tube and tubes throw a LOT of heat off. It was like watching a light bulb go off.

    • For #1, sounds good - I'm sure you have a list of these hospitals, right?

      For #2, see #1. I'm sure that since you are omniscient and know exactly how good any given hospital employee is, you trust that they are aligning it right. And if not, then they wouldn't have hired them, right! Really tight logic!

      For #3, blank stare. You do..know...that someone who performs e.g. 500 X-rays a year has a different risk profile than a single patient who gets 1 or 2 a year, right? I mean, surely you understand that right?

      • Re: (Score:2)

        by Bengie ( 1121981 )
        Having talked to several technicians who just stood next to me during x-rays, they all tell me the dosages are several magnitudes less than they use to be. Even if they stood right in the path where I was, the total amount they're exposed to each year wouldn't even show up. Be it dentist office, joint clinic, or the hospital, they're all tell me their body radiation exposure device used to show some activity after a month even when behind walls, but now they stand next to the devices and nothing..... Not on

    • Re: (Score:3, Insightful)

      by tlhIngan ( 30335 )

      I suspect the reason is simple - almost no one uses film for x-rays anymore. Film is not a sensitive medium, so they had to use much more x-ray radiation to get a clear image.

      Today's digital imagers are so sensitive that they require very low power sources. My dentist uses a USB digital imager but still has the old style X-ray emitters to save costs (they still work), so you still have to put up the mat.

      But when I did a chest X-ray and recently a shoulder x-ray, they just had a little stand with a thin curt

      • Re:Seriously? (Score:4, Informative)

        by tlhIngan ( 30335 ) <slashdot&worf,net> on Friday January 17, 2020 @05:26AM (#59628866)

        Another benefit of lowered dosages is more frequent imaging - I'm sure back when you had a lifetime limit of 18 chest x-rays, people would use it far more sparingly. But today when the dosage is so low, they're using it far more often, so you're getting better images with lower dosages far quicker means you can image more often without worrying about exceeding a lifetime limit of dosage.

        And that probably leads to better treatment since you can image more often and get better images in near real time.

        I believe if you halve the intensity you can do it 4 times as long. I wouldn't be surprised if x-rays exposure has been reduced to a tenth or even less, so you can have at least 100 times as many images these days. A lifetime limit of 1800 images is quite a bit more than than 18. If you estimate someone may live to 90, that would mean at most an x-ray every 5 years. But at today's dosage, that's 20 x-rays a year.

        • Re: (Score:2)

          by Bengie ( 1121981 )
          Wow, 18 total? When I went in for a chest x-ray several years ago because of stomach pains, the technician took several with me standing and several with my laying down. I asked them about taking so many and they just shrugged it off with "unless you're getting this weekly". They did have me wear a lead apron, but it just mostly covered my genitals.

          On this topic, had my gallbladder taken out. It's freaking outpatient and I only had 3 incisions. I was told I could immediately eat anything I wanted after th
      • The cool part about the imager, it's basically a CCD.
    • Employees who administer x-rays daily are at receiving more cumulative doses of radiation than someone who just gets a couple of x rays in their lifetime, which is why shielding the employees matters more than the patient.

    • 3. Risk from radiation is sufficiently large that employees who are substantially removed from the radiation source in 1/r^2 terms should be shielded, but patients don't need to worry? Right.

      A patient catches radiation from one x-ray, once.
      Radiology staff, if not shielded, would catch parts of every x-ray, for every patient, every day of the working week.

      That's why they also wear radiation monitoring patches (film badges) to keep monitoring their daily and lifetime exposure.
      Because they still do catch parts of of every x-ray, for every patient, every day of the working week. Only with shielding it's far less.

    • Reading through the summary one comes to the conclusions that ...

      1. There are hospitals that find their technicians mis-position lead aprons so frequently that they are increasing exposure to a fraction of patients that is MORE damaging than removing basic protection and thus increasing exposure for everyone. Me, I'll stay away from those hospitals, thanks, since their hiring procedures appear to be seriously lacking.

      2. Lead shields help, even if they are not perfect (i.e., they don't help with internal scatter). So, despite the fact that they are beneficial, because they are not perfect, we shouldn't use them at all. Right. Again, I'll stay away from hospitals that rely on reasoning like that.

      3. Risk from radiation is sufficiently large that employees who are substantially removed from the radiation source in 1/r^2 terms should be shielded, but patients don't need to worry? Right. I'll definitely be going to other hospitals, thanks.

      Some other considerations:

      (1) Single-dose levels have decreased to 1/20th the level from many decades ago when the safety procedures were first formed.

      (2) Sometimes incorrect positioning of the shield covers the intended target, requiring a second dose.

      (3) Sometimes adaptive systems increase the dose in response to a shield that covers the intended target.

  • Ask for an apron. Notice that the technician is safely behind a lead wall.

  • X-Ray sensors sense more than X-Rays! (Score:5, Informative)

    by BobC ( 101861 ) on Thursday January 16, 2020 @11:27PM (#59628546)

    X-Ray sensors are incredibly sensitive ("fast"), the goal being to minimize the X-Ray dose to the patient. But such sensors tend to get "sloppy", and sense far more than X-Rays. This is a problem, and lead aprons make it worse!

    The issue is that when X-Rays hit lead, the high-energy photons are absorbed then are re-emitted at lower energies, an effect called "X-Ray fluorescence". Many of these photons are still near X-Ray energies, and modern sensors are able to detect them.

    This means the resulting image can have lots of stray content, resulting in fuzziness and a loss of contrast.

    The details of how this all happens gets involved, but the bottom line is that keeping lead (and similar materials) far away improves image quality. Which in turn can permit the original exposure to be further reduced.

    And that's the net gain here: Lead X-Ray fluorescence makes the image worse, so the default response to get better images is to use a higher dose! So getting rid of the lead yields two benefits.

    • Who said lead? Lithium6 or lithium deuteride and a bit of beryllium in a lead honey comb may be a somewhat more expensive solution. I hear the Irish are using bundles of lead pencils and rubber bands as an effective radiation solution.

    • Sounds to me like we should improve the sensor instead of removing protection from patients.

      • Re: (Score:3)

        by BobC ( 101861 )

        That's the path that been followed, and it is nearing the limit of physics.

        To adequately penetrate the body and provide good contrast between flesh, cartilage and bone, only a relatively small range of X-Ray energies can get the job done.

        There are trade-offs between the strength of the X-Ray source, the duration of the X-Ray pulse, and the sensitivity of the sensor.

        The traditional approach is to use a short powerful pulse, which has many benefits both for imaging and for the patient. But the shorter the pu

    • Ah, this is the comment that makes sense. Thanks.

  • Radiation (Score:3)

    by tquasar ( 1405457 ) on Thursday January 16, 2020 @11:36PM (#59628562)
    Has the use become so common that is it used when it may not be necessary? Can dentists, MD's and other pros reply? Do people with chronic conditions get a higher exposure? I have had cavities since I was young and was often exposed to radiation. Lots of RC cola candy and other sugars when I was six or seven. My teeth were and still are in poor condition.

    • Re: (Score:2)

      by guruevi ( 827432 )

      The dosage of radiation in (modern) X-Ray machines is so low, you probably get more radiation flying a plane.

      That being said, you don't want to continuously beam someone for everything because sometimes things do go wrong and a lead apron won't protect you. Having unnecessary procedures exposes you to unnecessary risk, both from the procedure as well as the diagnosis - hence why, unlike in the TV shows, we don't do full body scans to figure out what is wrong with someone. Your dental x-rays won't damage you

    • Re: (Score:3, Interesting)

      by The Gingivist ( 6534576 )
      I am a dentist. the image quality and speed have changed so much even in the last 10 years. i almost always use a lead apron not because its needed, but because spending the time to convince a patient they dont need it is a waste. our new CBCT machine has an effective dose of 80% LESS than the previous years model when run in ultra low dose mode with almost no loss in quality. think of it like less light and cranking up the ISO sensitivity on your DSLR. its nuts how little radiation is needed. they are def

      • Re: (Score:2)

        by kackle ( 910159 )

        i would say all my retakes of my 3-d CBCT imaging is because of the apron.

        Why would an (chest?) apron get in the way of dental, x-ray pictures?

    • Re: (Score:2)

      by Kjella ( 173770 )

      A modern chest X-ray will give you about 0.1 mSv. The occupational limit is 50 mSv/year or the equivalent of 500 chest X-rays/year, though astronauts go even higher. At 35000 feet you get 0.003 mSv/hour extra so if airplane staff fly 2000 hours a year they get 6 mSv or the equivalent of 60 chest X-rays. Not all radiation is completely equal but it's almost impossible to reach dangerous levels through diagnostic imaging alone, even with intensive post-surgery surveillance. Usually it's in combination with ra

  • Modern x-ray machines are FAR weaker than old ones (Score:5, Insightful)

    by Ungrounded Lightning ( 62228 ) on Friday January 17, 2020 @03:27AM (#59628772) Journal

    As I understand it:

    Modern x-ray machines emit ORDERS OF MAGNITUDE less energy than old ones from mid-20th century. This is because, first, enormous improvements were made in the sensitivity of x-ray film, the n second, film was replaced with far more sensitive semiconductor image sensors that are close to single-photon counters.

    Each improvement in image sensor technology was accompanied by a reduction in beam current and thus x-ray intensity.

    When I was a kid there were machines in shoe stores which would shine enough x-rays through your feet to light up fluorescent screens - for minutes, while your dad and the shoe salesman discussed the fit of the shoe - over and over, while your little reproductive organs were irradiated and your feet ditto to the point of giving you the odd benign tumorous lump - which didn't help the shoes fit at all.

    Annually your hospital would give you a chest x-ray - "screening" for Tuberculosis.

    People born these days, even if they have a few cat scans, are likely to be exposed to less medical x-rays over a lifetime than ONE of those annual chest x-rays.

    • Re: (Score:3)

      by pz ( 113803 )

      Modern x-ray machines emit ORDERS OF MAGNITUDE less energy than old ones from mid-20th century. This is because, first, enormous improvements were made in the sensitivity of x-ray film, the n second, film was replaced with far more sensitive semiconductor image sensors that are close to single-photon counters.

      I've heard that many times, too. Doing a quick search, I found a couple of unsubstantiated remarks that there was a 70% and a 90% reduction switching from film to digital sensors. Those were unsubstantiated claims, so perhaps there's one order of magnitude there, perhaps. The single authoritative source I could find was this presentation:

      https://www.aapm.org/meetings/... [aapm.org]

      while they did not provide quantitative measurements for equivalent image quality, it appears they were pushing digital instead for bett

    • Funny you mention CAT or CT. A whole body CT takes about 20 minutes. A group of forward thinkers said how about if we mount a bunch of x-ray heads instead of just beaming the one. It brought the time down to 20 seconds and the overall radiation exposure down significantly. How long before we see this everywhere - give it 20-30 years. I recall my endodontist, I asked why we couldn't just regenerate teeth - she told me they were doing that in the labs 20 years ago.

  • Lead shielding likely increases dose absorbed, no matter what marginal gains in source exposure have been realized, and even when positioned correctly. Internal scatter is by far the largest contribution of dose hitting the shield. All it does is prevent radiation that was otherwise going to harmlessly leave the body from doing so, and reflecting a proportion of that radiation into more scatter and absorbed dose into the body. It was always done to placate patients (who often demand it), despite the fact t

  • Input from a medical physicist (Score:3, Informative)

    by nkeat ( 923753 ) on Friday January 17, 2020 @09:03AM (#59629172)
    Lead shielding has always been for reassurance more than safety. The output of an x-ray device is tightly limited (collimated) so that the direct beam outside the imaged field of view is pretty much zero - for a conventional x-ray unit, the field of view should coincide with the area that is lit up when the radiographer/tech is setting up the exposure. Irradiation outside this field is due to scatter, which if it interacts with any shielding, will likely be exiting the body, so there is close to no dose reduction. If there is lead apron overlying the chamber that sits behind the detector, and is used for exposure control, the presence of the apron could lead to increased dose (this would be pretty poor practise, but I guess it happens). Ultimately, I'm sure they've caused a lot more problems than they solve - they take time to set up, cost money to keep in good condition (the lead tends to crack and need testing and replacement) and are a good source for transmission of infection from one patient to another - most places will try to keep them clean, but that's difficult to do well. In the very early days of x-ray (50-100+ years ago), x-ray beams were largely uncollimated, less filtered, and a lead apron would have been useful to shield non target organs, as well as protecting operators who were often directly in the beam itself. Modern x-ray systems do use lower doses than historical devices - appropriate beam filtration, digital detectors, modern image processing have all made a difference; let's say to be on the generous side that we're approaching an order of magnitude reduction over the last 25 years or so I've been in medical physics. The chest x-ray and dental x-rays that come to mind for most people are actually very low dose procedures (think hours to days equivalent of naturally occurring background radiation). As an operator, it makes sense to be a decent distance away from an x-ray source, but the dose rates away from the beam are very low in 'conventional' x-ray rooms. In other situations, e.g. CT scanners, dynamic x-ray and interventional suites, the doses to the surrounding environment are higher and the beam may not be angled directly away from the operator, so more precaution is appropriate for the operators (lead aprons for the radiologists and techs are useful, lead glass screens are also used). The larger doses to the patients should be justified by the extra healthcare information provided by these types of imaging, but unnecessary repeated imaging should be avoided where possible.

  • So their insanely stupid reasoning is, that the staff is too fucking "dumb by choice" lazy to do it properly, and it couldawoulamaybea in *some* (far from all!) cases result in nullifying its use,

    so instead of telling the staff and machine manufacturers to do it *properly* or be fired(!),

    they *enable* and breed that behavior, and nullify natural selection ...

    Do you want a population of retards? Cause that's how you get a population of retards!

    Frankly, thia case of unnatural anti-selection should be treated

  • A few months ago, took bite wings at the dentist. Was surprised and pleased that they added ANOTHER lead collar around my neck. Cannot believe that anyone would propose LESS shielding. Especially for the operator, who would absorb aggregate radiation doing multiple x-rays per day. Of note, there's no clearing house for patients accumulating aggregate radiation across many health care providers.

  • However, experts continue to recommend that health care workers in the imaging area protect themselves with leaded barriers as a matter of occupational safety."

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