presentation given at ECR 2013 during the session "Tablets in radiology: friend or foe?"

1. Tablets for mobile (Tele-
)radiology
a critical appraisal
Dr. Erik R. Ranschaert
Radiologist
ECR 2013

2. Introduction
1. Mobile imaging
– trends and evolution
2. Technical aspects
– Display
– Bandwidth
– Safety & Security
3. Clinical use cases
– Mobile Radiology
– Teleradiology

3. Popularity of tablets
• More than 80% of physicians
own and use mobile devices
• Medicine is one of most
obvious use cases
– doctors are mobile
– work in spaces covered by Wi-Fi
– Have heavy information needs
• Approx. 25% of radiologists are
using them clinically
Source: Diagnostic Imaging website;
accessed Nov 25th 2102
“Taking the Pulse U.S. 2012,” Manhattan Research
“Mobile computing in radiology: challenges and benefits.” Diagnostic Imaging, Feb. 12, 2013

4. Why are iPads so popular among radiologists?
Convenience High potential
• Versatile, portable, high quality • To improve
display, touch screen communication, collaboration, co
• Low price vs other LCD displays nsultation and teaching
• access to data from multiple sites • To “streamline” communication
• reading of emergency cases and strengthen relationships with
(CT, MRI) comparable to PACS referring physicians
workstations* • To improve relationships with
patients by displaying images on
a more familiar device
*John S et al. The iPad tablet computer for mobile on-call radiology diagnosis? J Digit Imaging. 2012 May 5.

5. Disruptive technology
• A disruptive technology = new
product that eventually disrupts the
business model of the “incumbent”
technology
• Characteristics: simpler, cheaper,
lower-end, more convenient
• Not necessarily as good as higher-
end equipment, but good enough
• Performance/quality progressively
improves
• Diagnostic-quality mobile readers will
soon be commonplace
How low-end disruption occurs over time
Source: Wikipedia

6. Caution
• despite the appeal of the iPad, using it
requires a thoughtful approach
• we need to be careful not to implement
technology for the sake of technology
• If radiologists don’t analyse it and understand
it we may not get the full benefit

7. iPad and teleradiology
• Is iPad suited for (tele)radiology purposes?
• Technical aspects
• Clinical use cases
• Experience, testimonies

8. Technical aspects
• Various technical
aspects need to be
considered:
1. Display
2. Software (viewers)
3. Bandwith
4. Security and Safety

9. Size
9.7 inch = 25 cm
• .
– for diagnostic purposes a
display needs to be 20-24 inch
(51-61 cm) diagonal, unless
using a larger panel to serve as
pair of monitors 21.3 inch = 54,1 cm
– for clinical review: anything
goes
• iPhone is 3,5 inch (9 cm)
• iPad is 9,7 inch (25 cm)
Copyright E. R. Ranschaert

10. Resolution of display
• Ideally 2-3 MP for diagnostic purposes
• 5 MP is required for mammography

11. Luminance of display
• DIN 6868-157 = German Industry norm
• Luminance:
Source: Image quality assurance in diagnostic X-ray departments - Part 157:
RöV acceptance and constancy test of image display systems in their environment (2012)

12. Specifications
iPad
Barco MDCC- iPhone 4 mini iPad3
iPad 2 7.9”
2121 “Retina” “Retina”
1024 x 768
0.8 MP
Display 163 PPI
21.3” 3.5” 9.7” 9.7”
IPS LCD
1600x1200 960x640 1024x768 2048x1536
Resolution (2 MP) (0,6 MP) (0,8 MP) (3 MP)
430 cd/m2 370 cd/m2
Max luminance 700 cd/m2 480 cd/m2
(ACR advises 171) (decrease vs iPad2)
Pixel Pitch 0,270 mm 0,078 mm 0,192 mm 0,096 mm
PPI (dots/inch) 120 326 132 264
Contrast ratio 1100:1 1242:1 775:1 839:1
Color depth 30 bit 24 bit 24 bit 24 bit/pixel
Price 4500 $ 590 $ 399-529 $ 499-699 $
Copyright E. R. Ranschaert

13. Pixel Pitch
• iPad3 has smaller pixel pitch
than diagnostic LCD
• iPad3 can display smaller
iPhone details but overall image is
smaller
Megapixels Pixel pitch
• Smaller PP does not
LCD 1-2 MP 0,280 mm
necessarily mean better
LCD 3 MP 0,210 mm
performance for clinical task:
LCD 6 MP 0,200 mm
iPhone: 0,6 0,078 mm
• Human sight might not be
iPad2: 0,8 0,192 mm
able to see smaller details
iPad3: 3 0,096 mm
without aid of magnification

14. Contrast ratio
• ability to produce the bright whites
and the dark blacks
• DIN 6868-157 requires ratio ≥ 100:1 for diagnosis
• AAPM requires
• 250:1 for diagnosis
• 100:1 for clinical review
• CR changes rapidly with viewing angles
– ± 10:1 for viewing angles of ≥ 85°
Sources:
Carrein G, Barco White Paper on characteristics of CRT and LCD displays
Indrajit et al., Indian J Radiol. Imaging 2009

15. Contrast ratio
• LCD’s range from 450:1 - 600:1
• can be as high as 1000:1
• ratios > 600:1 provide little improvement
• iPad contrast ratio is 839:1
Source: Carrein G, Barco White Paper on characteristics of CRT and LCD displays
Indrajit et al., Indian J Radiol. Imaging 2009

16. Color bit depth
• number of bits used to
describe the color of a
Bit depth Color single pixel
combinations
2 bit 22 2
• knowledge of color bit
4 bit 24 16
depth is useful when
8 bit 28 256 working with color
16 bit 216 65.536 Doppler and CT/MRI
24 bit 220 16.777.216 with color-encoded
32 bit 24 + 8 bit 16.777.216 functional imaging
• ≥ 30 bit = “deep color”
Source: Indrajit et al., Indian J Radiol. Imaging 2009

17. Influence of ambient light
• Importance of ambient
lighting conditions
• Highly reflective touch
screen
– Influence of sun and lights
– “fingerprints”
– viewing angle
• Calibration tools?
Source: Review Apple iPad 3rd Gen. 2012 4G TabletJ. Simon Leitner / Klaus Hinum
Source: Indrajit et al., Indian J Radiol. Imaging 2009
Copyright E. R. Ranschaert

18. Calibration issues
• High quality display needs reliable calibration to
make a confident diagnosis
• iPads have high quality displays
– luminosity, contrast and pixel density even better than
professional LCD
• iPad has
– No DICOM calibration
– No quality assurance during display’s life
– No contrast control

19. Calibration iPad
• iPad:
– no access to video subsystem
for calibration
– impossible to use a utility
operating separately from
viewing application (as in PACS)
– no photometer
• Solution:
– “Tap test” to adjust
compliance with DICOM curve Barco QA Web mobile

20. Display properties tablets
• viewing angles, brightness and contrast levels can
match up to diagnostic monitors
• Mobile displays cannot compete with the screen size
and resolution of modern medical displays
– they may play an important role in radiology
– they cannot replace but they can function as cost-effective
extension of workstations
Source: Székely et al, EJR 2013 Copyright E. R. Ranschaert

21. Technical aspects
1. Display
2. Software (viewers)
a. Viewing software
b. Volume rendering sw
3. Bandwith
4. Security and Safety

22. Viewing software
• Mobile MIM viewer
– First mobile app for diagnostic radiology to receive FDA
clearance
– cleared in February 2011, process started in 2008
• approved for viewing images and making medical
diagnoses in
– CT, MRI and nuclear medical technology
• mammography is specifically excluded

23. FDA regulation of mobile viewers
• Since the approval of mobile MIM the FDA has put
greater focus on medical mobile apps (software)
• Although FDA has not yet released its official
guidance for mobile medical apps, industry experts
anticipate the agency to claim regulatory authority
over any app that helps providers make a diagnosis
• Currently mobile DICOM viewers can only be used
when and where there is no access to a workstation
Source: FDA clears first diagnostic radiology application for mobile devices
Diagnostic Imaging, Feb 12, 2013

24. Top Five Apps for Radiology
• Mobile MIM*
• Resolution MD mobile*
• eFilm mobile HD
• Osirix HD*
• iClarity
All these viewers have basic viewing
functionality and safe connection
protocols
Source: RSNA 2012 poster LL-INE2523 R. Delgado et al:
Radiologic Images on Your iPad: Top Five Apps
* approved by the US FDA for its clinical use when a close by workstation is not available

26. HTML5 DICOM viewers
• DICOM web-viewers can be used
without installing additional
software
• “Zero-footprint” principle: no
installation, no data storage at
client
• Advantage for security reasons
• Cross-platform usage
• Vendor-neutral: possible to
integrate with any PACS

27. 3D volume rendering apps
• Turns the iPad into a
mobile workstation
• Postprocessing in real-
time on mobile device
• Resolution MD

28. Technical aspects
1. Display
2. Software (viewers)
3. Bandwith
4. Security and Safety

29. Wi-Fi for image transmission
• For routine reading on large Network type
Speed Speed
immobile train/car
monitors ± 3-5 Mbps is needed
• Small screens mean less need Wifi 802.11 b 5,9 Mbps -
for speed thus less BW
• Wavelet technology needs less Wifi 802.11 g 25 Mbps -
speed (“visually lossless”
Wifi 802.11 n 100 Mbps -
compression technique)
• Mobility goes at cost of slower 3G
14 Mbps
144 Kbps
(2 Mpbs real)
downloading speed
– E.g. CT skull with 3G 4G 1000 Mbps 100 Mbps
– 10 sec (still) vs. 3 min (mobile)
Source: Choudri AF et al, J Digit Imaging 2011 Apr 24(2):184-9
Copyright E. R. Ranschaert

30. Copyright E. R. Ranschaert
Mobile data transmission
Est. image size Est. transmission speed
Resolution MB 3G 4G
2 sec (S) < 1 sec (S)
Chest X-ray 2048 x 2400 x 16 1,6 – 3,2
3 min (M) < 1 min (M)
10 sec – 3 min (S) 1 sec (S)
CT 512 x 512 x 16 20 - 200
15 min – 2 h (M) 16 sec (M)
1 – 10 sec (S) < 1 sec (S)
MRI 256 x 256 x 8 2 - 20
2 – 15 min (M) 1 sec (M)
http://www.jhuyett.com/bandwidth.html S = still, M = moving

31. Technical aspects
1. Display
2. Software (viewers)
3. Bandwith
4. Security and Safety
Copyright E. R. Ranschaert

32. BYOD
• Bring Your Own Device
• Risk:
– Lack of essential
security controls
– Higher risk of malware
infection
– Potential loss/theft of
mobile devices

33. iPad & Security risks
• Consumer device: not designed for protecting
sensitive patient data
• Risk to the security of patient records if
downloaded & stored on tablet
• Risk if images are shared using unsecure
platforms
McEntee et al: 5 April 2012; Proc. of SPIE Vol. 8318 DOI: 10.1117/12.913754

34. Secure image sharing?
• Dropbox?
✗
• Allows to uploading and
sharing of images
• Dropbox does not have
HIPAA certifications for
use in health care
settings

35. Copyright E. R. Ranschaert
Massive increase in data breaches
• 97% of US clinicians access patient data on mobile
devices
• Only 38% of HC organisations in US have mobile
saftety policies
• 94% of US hospitals had data breach in past 2 yrs
• In 2010 only 30% reported >5 incidents
• Most important cause is loss or theft of portable
digital equipment (46%)
Source: Third Annual Benchmark Study on Patient Privacy & Data Security, Dec 2012
Diagnostic Imaging,Feb. 12, 2013: 2011 HIMSS survey

36. Copyright E. R. Ranschaert
Tablets are vulnerable to loss/theft
Source: Third Annual Benchmark Study on Patient Privacy & Data Security, Dec 2012

37. Measures to be taken
• Adapted IT logistics for wireless network
• Mobile Device Management Tools
– creation of “safe environment” on BYOD
– access after security check
– data remain within “safe container” on device
– data not accessible for other “private apps” on device
– remote “wiping” of container is possible
• Increased insurance premiums for hospitals
• Image sharing through secured platforms only
Copyright E. R. Ranschaert

38. Image32
• Secure accounts
• Protected health-information is
stripped-out: name, MR number
• Only study-identifiers, no patient-
identifiers
• On-line sharing and simultaneous
viewing on any device
• Online viewer is class-I device:
not for diagnostic use

39. Clinical use cases
• most wanted in emergency setting
– CT brain for evaluation of acute stroke
– Chest XR detection of pneumothorax
– CTA chest for pulmonary embolism
• Accurate and fast, similar results to
reading workstation
Source: kely A, et al. Smartphones, tablets and mobile applications for radiology. Eur J Radiol (2013)

40. Other clinical use-cases
• Chest:
– Chest CT for pulmonary
nodules (metastases)
– Chest XR for tuberculosis
• Abdominal:
– CT appendicitis
– Virtual colonoscopy
• MSK
– spine MRI (spinal injury)
– Knee MRI
Image of patient with gout is displayed with syngo.via
WebViewer. (Provided by Siemens)

41. User’s experience
Copyright E. R. Ranschaert

42. User’s experience (1)
• Screen OK for CT/MRI
• Not for X-ray/mammo
• Good for on-call
radiologists
• Good for giving second
opinion to
clinician/resident
• Bed-side demonstration
• Not for routine
reporting
Copyright E. R. Ranschaert

43. User’s experience (2)
• Main concern is lack of DICOM-calibration
• Fine for less demanding modalities or
maybe selected radiographs ...
Copyright E. R. Ranschaert

44. Advantages iPad for radiology
Hardware Software
• Convenience, versatility • Easy-to-use viewer apps
• Flexibility: inside and • 3D viewing software
outside radiology dpt. • HTML5 viewers for safe
access to images and RIS
• High res touch screen information
• Long lasting battery • Image sharing is facilitated
• Low weight • Integrated communication
tools
• Low price
• Multi-tasking
Copyright E. R. Ranschaert

45. Disadvantages iPad for radiology
Hardware limitations Software limitations
• Screen size, single screen • No DICOM calibration
• Touch screen only • No hanging protocols
• Processor and memory • No integration of priors
limitations • No functional & volumetric
• No multi-tasking assessments
• Limited security of tablets • No access to RIS worklist*
• Scrolling difficult
– strain to fingers
– difficult to control speed
*Exception: HTML5 viewer
Copyright E. R. Ranschaert

46. Emerging teleradiology
applications
• free mobile application
• cloud based
• instant consultation
• helps
– solo-radiologists
– practitionars in remote
in areas
– those who cannot afford
PACS

47. Conclusion
• Mobile devices
– should not be used for routine primary diagnosis
– need adapted safety policies and ICT environment
– are causing a shift towards easier image sharing &
communication with peers, referring doctors and patients
• They are therefore likely to reshape radiology

48. Thank you!
e.ranschaert@jbz.nl