Study confirms iPad’s shortcomings for diagnostic radiology

By: Neil Versel | Feb 29, 2012        

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israel ipadNew research from Australia adds to the evidence that the iPad is a handy but still less-than-perfect tool for radiologists.

In a study presented at the recent International Society for Optical Engineering medical imaging conference in San Diego, Dr. Mark McEntee of the University of Sydney found that the iPad and similar touch-screen tablets are just as good as standard LCD monitors for viewing medical images. But both tablets and consumer-grade LCD screens are suitable only as “secondary” displays, only when high-resolution radiology monitors are not available.

“iPads and other secondary screens should not be used for clinical diagnosis,” McEntee told Australian publication eHealthspace.org. “There is a range of safety concerns associated with using mobile screens.”

McEntee said that high-resolution clinical monitors allow viewers to pick up more “just noticeable differences” in medical images than with iPads or standard LCD screens. He came to this conclusion after having eight U.S. board-certified radiologists attempt to identify intracranial bleeding, fractures and lung nodules from x-rays and other scans.

Primary radiology displays have a resolution of 508 to 750 dots per inch, much greater than the 130 dpi of iPads and desktop monitors, according to the University of Sydney. They also tend to be brighter than consumer-oriented displays.

However, McEntee found no significant difference between the iPad and a standard LCD monitor, making tablets wonderful for freeing physicians from desktop computers when doing inpatient rounds. “In the past, doctors would do their rounds in the wards, returning to a desktop computer to view images. Now they can do it at the bedside with an iPad or other tablet computer,” McEntee said in an article published by the school.

“When no primary display device exists, diagnoses can be carried out on a secondary display device, such as an iPad, but this is only in the most urgent of cases, for example to determine whether a patient is suffering from an intracranial bleed,” McEntee added.

This is similar to the requirement that the U.S. Food and Drug Administration has imposed in clearing several mobile medical image viewing apps for clinical usage, such as offerings from Mobile MIM, GE Healthcare and Calgary Scientific. “This device is not intended to replace full workstations and should be used only when there is no access to a workstation,” the FDA stated in a 510(k) clearance notice for Mobile MIM. The FDA specifically excluded mammography from its clearance.

  • Brian Anderson

    Is this a joke? I was linked here by a tweet that says “Even if the iPad 3 has a retina display, it’s still too low-res for use by radiologists.”

    I’m sorry, but do you understand what retina display means? The human eye can’t tell the difference past a certain point. Assuming the screen were bright enough (which it is), you would not be able to tell the difference between an iPad3 (assuming it comes with retina display) and these monitors.

  • http://methylblue.com/ Max Howell

    iPad 3 dpi won’t be “retina” its dpi is quite a bit less than iPhone 4’s. And even then iPhone retina is debatable. Just because you read it in Apple marketing and on Techcrunch doesn’t make it scientific. You sir, are a lemming, believing the crap that blogs spout without asking for evidence.

  • Mark

    I agree with Max. Unfortunately Apple fanboys are everywhere.

    Resolution of a retina display is only part of the problem anyway. Radiologists need contrast ratios that a retina display cannot provide. I imagine screen size is a big issue here too.

  • http://drrjv.wordpress.com/ drrjv

    The iPad may not be good for mammography but will be fine for most (all) digital imaging such as MR, CT, etc.

    Here is a recent article of interest:

    http://www.auntminnie.com/index.aspx?sec=sup&sub=mri&pag=dis&ItemID=98491&wf=4805
    iPhone shows high accuracy for knee MRIThe iPhone is a fine platform for interpreting knee MRI images, and for most injuries it’s equivalent to a workstation, according to a new study by Canadian researchers that was presented earlier this month at the American Academy of Orthopaedic Surgeons (AAOS) meeting in San Francisco.

  • http://ObamaPacman.com ObamaPacman

    Perhaps the existing devices are very cumbersome to zoom, thus they need to plaster their face on the high DPI display instead.

  • guest

    McEntee had done a great job, by providing significant information about the ipad. As in healthcare, every device must be perfect to provide exact information to the doctor.
    Apple guys can definitely take it as opportunity to enhance their product more.

  • Neil Versel

    What do you mean by “is this a joke”? Sounds like you have an issue with the tweeter, not the study or this article.

  • Brian Anderson

    “iPad 3 dpi won’t be “retina” its dpi is quite a bit less than iPhone 4’s” …. literally three sentences later …. “You sir, are a lemming, believing the crap that blogs spout without asking for evidence.”

    How could you possibly know what the dpi of the iPad3 is. We don’t even know if it’s CALLED the iPad3. Good lord what asinine hypocrisy lol. Hilarious that you actually take yourself seriously.

  • Brian Anderson

    I suppose that’s probably fair, but the article still kind of suggests the same.

  • Brian Anderson

    The screen size thing I could understand. In fact, that seems like a pretty reasonable argument. Arguing that people can’t see results on anything less than 508 dpi, however, is not.

  • http://tedwise.com Ted Wise

    According to Apple’s definition (and it’s their term) it’s the resolution necessary to make individual pixels impossible to discern for a given distance. An iPhone screen needs to have a higher DPI since it’s held closer to the face. An iPad can have a lower DPI and still be classified as a retina display. And laptop screens can have still lower DPIs and yet match the definition.

    I’m a happy user of Homebrew BTW – thanks for coming up with that.

  • http://about.me/evfreed Evan Freedman

    Wait, radiologists have actually been using iPads to conduct precision observation and make clinical diagnosis? I just thought (or assumed, rather) that viewing DICOM imagery on tablets was intended for reviewing images with patients or surveying images while on the go.

    People have seriously been using iPads to make diagnosis? I would not feel comfortable with that in the slightest if I were the patient. I wonder if the method and tools utilized in reaching the diagnosis (iPad in this case) would even be made aware to the patient.

    Although this is only somewhat related, I will still mention that my other major concern remains to be the efficacy of sterilizing tablets. Just think of the sheer number of fingers touching that screen… and none of those fingers can be wearing gloves either! I am not entirely convinced by the protocols that have been developed thus far.

  • xraydoc

    as a radiologist, i can tell you that this study is bogus.  my monitor is 120 dpi and I use it all day long for diagnosis.

  • netwebber

    I am unaware of any radiology displays over 161ppi. This appears to be the highest: http://www.ndssi.com/products/dome/ex-grayscale/s10.php
    Where are these 500-750dpi “Class I” displays? I can’t find anything about DPI or PPI on the American College of Radiology or the Royal College’s website.

  • netwebber

    And as far as I know, the 204ppi IBM T221 was never DICOM certified.

  • Mike, curious reader/skeptic

    These numbers can’t be real.  That would make them about .035mm pixel pitch.  That’s incredibly tiny.  Who makes displays with such fine resolution?  Even the 30 inch Barco Medical 6MP Coronis MDCC-6130-DL has only 3280 X 2048 Pixel Resolution – which is fantastic, but nowhere near 750dpi.

  • Ruudversteeg

    Nice, someone being IT manager debating about the ability of the human eye on diagnostic images. That’s all pure theoretica about retinal.
    The statemen”t “assuming the screen were brigtht enough says it all. I’m sorry, but you have no idea what your talking about!
    I know from my profession what is takes to diagnose medical images like MRI/XRAY/CT.
    There is now way that a commercial screen (or an Ipad for that matter) will be able to display waht a High res. pro monitor will display is the present time.

  • http://www.healthfusion.com/web-based.asp MediTouch EHR

    The diagnostic limitations don’t seem to rest with the iPad EHR or any other hardware or software.  The limitations seem to reside with the DICOM standard — huge image file uploads and downloads are not conducive to any branch of clinical medicine.  even advanced EHR drawing tools like MediDraw, are unable to truly utilize the DICOM standard.  But if you fin the fault truly rests with the iPad current limitations then the retina display of the new iPad should easily solve the issue. 

  • Bob

    There are no screens that approach 500dpi in use for diagnostic imaging!!

    Cranial bleeds are diagnosed generally with CT. That is a small-matrix image and such does not need a diagnostic monitor. Only plain-film and mamo need “cleared” monitors. The average density of a barco is 120ppi.

  • DPD

    what about ultrasound images on ipad2??

  • Jeffj5

    The new iPad has resolution of 264 dpi which is far greater than any diagnostic monitors I use (including for mammography which is about 160 dpi)