The ‘MedIPad Era’ dawns lures Doctors and medical professionals

By Live Dr - Wed Sep 08, 12:01 pm

The iPad–Radiology’s Sharper Image?

It may still be a work in progress, but Apple’s tablet device could herald a new computing age that extends to the radiology suite.

Apple Inc. has had a tremendous impact on my life. My first “real” computer was a Macintosh Plus, and I’ve finally returned to the Mac fold with the purchase of a MacBook Pro i7. I’m on my second iPhone, and my kids have gone through a plethora of iPods. Apple wasn’t the first company to sell any of these things, but they now own the mobile music market, as well as a huge chunk of the smartphone arena. The Macintosh returned from near-death to account for 10 percent of computer sales in the U.S.1

A new Apple product is newsworthy, and the company plays its mystique to the hilt, dropping just enough hints on the upcoming toy to keep us waiting anxiously. By the time the iPad was officially announced on Jan. 27, we mostly knew what to expect–a tablet computer based on the iPhone operating system. And that’s what we got–but there’s more here than meets the eye.

In the beginning

Indulge me in a historical aside. The iPad isn’t Apple’s first foray into tablet computers. Ever heard of the Newton? I had one, back in 1994. It didn’t work very well.

Did you know that there was another tablet-computer/personal communicator in Apple’s pipeline way back when? In the early days of the Newton development project, Apple had two teams developing portable personal computing devices. Pocket Crystal was meant to be the portable mobile device, and the Newton was originally positioned as a somewhat larger tablet. Eventually, Apple had to decide which to run with, and the Newton won.

Pocket Crystal was spun off as a separate company called General Magic, which commercialized its Magic Cap operating system. The early versions suffered from a memory leak problem; by the time the bug was squashed, its credibility had been damaged irreparably.2

Features and dimensions

For those who have spent most of 2010 in a cave–or at least without broadband (which is tantamount to living in a cave)–the iPad is a wafer-thin computer with a brilliant color screen, a “Home” button on the front, volume control, a power switch, an orientation-lock switch and an earphone jack on the sides. The form factor, screen and Multi-Touch input are the iPad’s key features. From Apple.com:

The Multi-Touch screen on iPad is based on the same revolutionary technology on iPhone. But the technology has been completely reengineered for the larger iPad surface, making it extremely precise and responsive. So whether you’re zooming in on a map, flicking through your photos, or deleting an e-mail, iPad responds with incredible accuracy. And it does just what you want it to.

One of the first things you’ll notice about iPad is how thin and light it is. The screen is 9.7 inches measured diagonally. So overall, it’s slightly smaller than a magazine. At just 1.5 pounds and 0.5 inch thin, you can use it anywhere. And a slight curve to the back makes it easy to pick up and comfortable to hold.3

The 242.8 mm (9.56 inches) (height) x 189.7 mm (7.47 inches) (width) x 13.4 mm (0.53 inches) (thickness) machine will apparently fit into a pocket of a white coat, but just barely. Perhaps bib overalls (but in white) with the large pocket in the front would better suit the iPad-carrying physician?

The iPad’s A4 processor runs at 1GHz (although Apple won’t confirm this), and it has 256 MB of DRAM built onto the processor housing. The user can choose 16, 32 or 64 GB of flash memory for storing music, pictures, videos and, of course, applications.

The iPad screen has a rather remarkable resolution for its size, with 1024 x 768 pixels (XGA) and a 4:3 aspect ratio; measures 9.7 inches (25 cm) diagonally; and has an LED backlight. (Contrast this with the new iPhone 4 screen, which, at 326 pixels per inch, has supposedly more pixels than the human retina can see, and a resolution of 960 x 640.) Is the iPad screen adequate for diagnostic reads–at least for digital, cross-sectional imaging? Yes, according to Stephan Popp, CEO of aycan Digital:

We at aycan have measured the iPad display according to the DIN V 6868-57:2001-02 (Consistency and uniformity testing for medical displays) … The iPad exceeds the values for medical displays category A (suitable for all kind of medical images, except mammography).4

  1. Luminance (min): 1,88 cd/m2
  2. Luminance (max): 363 cd/m2
  3. Contrast ratio: 193:1
  4. Ls: 0.33 cd/m2 (display turned off, luminance of the ambient light on the display)

This information differed from numbers quoted in an AuntMinnie.com article:

(T)he iPad has a maximum luminance of 270 cd/m2, which, while higher than the average of 150-200 cd/m2 seen in off-the-shelf displays, is much lower than your average primary interpretation display, which has an average maximum luminance of 500-600 cd/m2. The iPad’s minimum luminance is 0.3 cd/m2, which yields a still-impressive contrast ratio of 900:1 for a portable device.5

Radiology viewing apps

My goal for this article was to evaluate from the radiologist’s perspective just how useful this little gem might be in viewing images. (We’ll leave other stuff like perusing journals and checking electronic medical records [EMRs] for another time.)

Several iPhone viewing apps are available on iTunes. At this point, no dedicated iPad viewing apps are available, but the iPhone apps function well in magnified mode. For my intensive research on this piece, I’ve stolen my son’s iPad and used it to download viewers from Merge Healthcare (eFilm Mobile), OsiriX and iCRco Inc. (iClarity). I’ve also investigated Mobile MIM (MIMvista) and ResolutionMD from Calgary Scientific.

Today’s radiology viewing apps are bare-bones programs, with half their code devoted to moving image files onto the mobile device. As with any other PACS viewer, some connection to the Mother Ship is required, and by and large, these apps function as extensions of the desktop viewer. OsiriX goes a step beyond with the ability to interface via DICOM Query/Retrieve with any DICOM server, at least in theory, as well as with an OsiriX Web Server. iClarity has a descent search function.

CoActiv has leveraged the connectivity of the OsiriX app and integrated it into its EXAM-PACS product. “Rather than reinvent a working wheel,” says Ed Heere, CoActiv president and CEO, “we chose to align ourselves with the OsiriX group and do a low-level bidirectional link to the existing iPhone app and work to further the much more attractive and useful iPad app in development. This methodology gave us a working app that was up and running by RSNA [the Radiological Society of North America] last year. We suspect that the iPad is . the real ‘future’ in mobile radiology on many levels.” CoActiv does plan to create something even better: “Once the FDA position [on mobile radiology viewers] is clear, we can all put 100 percent of our efforts toward development of a broad range of PACS apps for both the iPad [and other platforms].”

Readers of my blog (www.doctordalai.com) will recognize me as a GUI (graphical user interface) snob, and here’s where our current viewer selection falls short. Screenshots from the OsiriX Mobile, Merge Mobile and iClarity viewers (see Figs. 1-3) show a very simple interface, with tools for window and level adjustments, zooming, scrolling through a series, and rudimentary measurement. All take advantage of the Multi-Touch iPad screen commands to provide these functions via hand gestures. These viewers are fairly easy to use once you’ve established the connection to your server. While I didn’t run any resolution or contrast tests, I found the images eye-pleasing, even running the iPad in magnified mode with apps meant for the smaller iPhone screen.

All the viewers I’ve just described have disclaimers stating that the images are not to be used for diagnosis, and I won’t dispute that disclaimer with what we have so far. And to be honest, computed radiography exams (CRs) don’t look as good on the iPad as the cross-sectional modalities (see Figure 4).

Still, the iPad screen should be adequate for diagnosis, although it can’t be calibrated. But how many of us use standard Dell consumer-grade monitors here and there instead of “proper” medical-grade equipment? Quite a few, I think. Perhaps Apple will create a medical version of the iPad with an advanced display. (I’d love to see the iPhone’s Retina display in iPad size–or on my desktop monitor, for that matter.)

A mobile viewer of this sort has numerous issues. An optimist at heart, I’m convinced that Health Insurance Portability and Accountability Act (HIPAA) compliance and the like can be accomplished easily

The ultimate question is whether the iPad will be useful as a radiology viewer. After much fooling around, I can honestly answer “Maybe” or even “Probably.” With today’s software, the iPad can be a very basic–but very portable–viewer. If that’s as far as we get, I likely wouldn’t go out and buy one just for that purpose. But I think we’re at the very beginning of something revolutionary.

The 3-D rendering in Figure 5 (performed on an OsiriX Macintosh client) gives a taste of what’s possible with the iPad. The applications need to progress beyond simple viewers and become more robust. Yes, I’m advocating full ports of PACS viewing software to the iPad. The rather low RAM (256 MB) will be a hindrance, but the next iteration of hardware likely will have more, and maybe someone will find a way to use the huge amount of available flash memory as a virtual RAM-disk, as we once saw regularly with older PCs.

Mobile MIM was the first iPhone medical app. Now in version 2.0, it’s available in several countries, but the U.S. isn’t one of them. Mobile MIM gives us a glimpse of where we can go with a (mostly) thick client. It has some rather powerful tools, including–remarkably–fusion. The PET or the CT component of a hybrid exam can be blended in or out of the image, window and level presets exist for CT, and various color maps are available for PET (see Figure 6). Also, the viewer can display other modalities, such as CR. MIM offers a much richer palette of tools, including 3-D localization for multiplanar images, annotation and measurement of SUV (standard uptake value) on PET, in addition to the old plain ruler. The bad news (beyond the fact that you can’t get it yet) is that you need the MIM Cloud or the MIM 5.1 workstation to port data to the app. But Mobile MIM certainly served as a proof-of-concept, demonstrating just how powerful this platform can become. An aside: It’s the first “universal” radiology app that supports the iPhone as well as the iPad with separate interfaces, and it is designed for diagnosis, supporting full-resolution images.  (Mobile MIM was my justification for buying my first iPhone, by the way.)

There is one brute-force approach to getting a real PACS client on your iPad today, if your IT department is game: You could connect to PACS via a virtual desktop, as our facility has made possible with our Agfa IMPAX via Citrix (see Figure 7). Note the little 2 x 3 cell Citrix control panel at the bottom of the image. Tap this panel to change from panning to scrolling to virtual keyboard. The approach actually does work–barely–but trying to perform right-clicks and accessing tools and the like is tedious, to say the least. Sometimes, it can be next to impossible. Layering Citrix on top of everything else can slow things to a crawl.  Using LogMeIn or another remote-control program would be a minor improvement but might breach security protocols. No, this isn’t really the answer.

The ultimate solution probably will involve server-side processing and rendering. Even if the iPad itself is computationally overwhelmed by high-level visualization, it could serve as a portal into a big server that can handle such things. (Certainly this can be done in a more optimal manner than with the rather clunky Citrix interface!) A thin computer deserves a very thin client, or even a zero-client solution, and that may be the architecture in the iPad’s future. (Of course, no Flash programs are allowed in this scenario, thanks to Apple.) Picture the rendering above with Multi-Touch controls that allow on-screen manipulation of the image in real time with finger gestures. All we need is the right software and the right connection.  How long will we have wait for this technological panacea?

As usual, if I’ve come up with a wonderful idea, someone else has had it first. With its ResolutionMD Mobile app, Calgary Scientific Inc. has just about perfected the approach I thought was years away. This app has already received approval by Health Canada for diagnostic use by Canadian physicians; it has also received FDA approval and been given the CE Mark for the European market. So far, ResMD is only dedicated for the iPhone, but an iPad version is coming shortly.6

ResolutionMD is based on Calgary’s PureWeb platform, which can fully Web-enable just about any software and make it work remotely on a mobile device or with a Web browser. When properly configured, ResMD will be able to search across any connected PACS and display any DICOM image. But what you see isn’t stored on the iPad. “We drive server-side rending . in fact, so much so that no patient information or data is ever copied or moved to the handheld device,” says Bryon Osing, PhD, CEO of Calgary Scientific. “All images/data are rendered on the server side, and application is virtually presented on the handheld device . with only a tiny trickle of data feeding the device to create the output on the screen. When the session is over, it is like nothing was ever there . as it never was. It is 100 percent secure.  The only thing the handheld device does is host a tiny generic applet that allows us to utilize the native touch-screen controls of the device and facilitate communication with the server.” HIPAA problem solved! And it’s easy to use: The app takes full advantage of the Multi-Touch commands, and with the number-crunching performed on the server and not on the iPad, the user can perform an instant volume rendering and twirl it around on the screen in 3-D with the flick of a finger. (Figure 8) This is where medical imaging apps on the iPad are headed, folks.

The iPad heralds a new age of computing, and radiology should be ready to embrace the concept. Wired magazine recently offered a glimpse into where Apple and other computer companies are taking us:

Even though the iPad looks like an iPhone built for the supersize inhabitants of Pandora, its ambitions are as much about shrinking our laptops as about stretching our smartphones. Yes, the iPad is designed for reading, gaming and media consumption. But it also represents an ambitious rethinking of how we use computers. No more files and folders, physical keyboards and mouses. Instead, the iPad offers a streamlined yet powerful intuitive experience that’s psychically in tune with our mobile, attention-challenged, super-connected new century. Instant-on power. Lightning-fast multi-touch response … The iPad is the first embodiment of an entirely new category, one that [Apple co-founder Steve] Jobs hopes will write the obituary for the computing paradigm that Apple itself helped develop. If Jobs has his way, before long we may be using our laptops primarily as base stations for syncing our iPads.

The fact is, the way we use computers is outmoded. The graphical user interface that’s still part of our daily existence was forged in the 1960s and ’70s, even before IBM got into the PC business. Most of the software we use today has its origins in the pre-Internet era, when storage was at a premium, machines ran thousands of times slower, and applications were sold in shrink-wrapped boxes for hundreds of dollars. With the iPad, Apple is making its play to become the center of a post-PC era …7

I don’t think the iPad interface will replace our PC-based PACS anytime soon. However, if software (and hardware) development progresses as I think it will, I predict we will see a lot of the iPad in our departments–and, more importantly, outside the radiology suite.

If only my old Newton were around to see its offspring!


1.    www.gartner.com/it/page.jsp?id=1401136

2.    http://myapplenewton.blogspot.com/2009/08/defying-gravity-magic-cap.html

3.    www.apple.com/ipad/design

4.    www.auntminnie.com/forum/m.aspx?sec=dsc&sub=pac&m=262175

5.    www.auntminnie.com/index.asp?Sec=sup&Sub=adv&Pag=dis&ItemId=91105

6.    www.imedicalapps.com/2010/06/resolution-md-mobile-calgary-scientific-ipad

7.    www.wired.com/magazine/2010/03/ff_tablet_levy

Sam Friedman, MD, is chief technical officer (CTO) and medical director of nuclear medicine at Pitts Radiology, Columbia, S.C., and a radiology blogger (www.doctordalai.com).



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