From: trevorc@uwovax.uwo.ca
Subject: RSNA '92 - Another point of view
Organization: Nuclear Medicine, U. Western Ontario, Canada
Date: Mon, 14 Dec 1992 12:58:53 GMT

Posted by permission of Robert Zimmerman, Brigham & Women's Hospital,
Boston, MQA
----------------
From: zimmer%bwnmr4@harvard.harvard.edu (Bob Zimmerman)

                   Report on 1992 RSNA Meeting 

                        Robert E. Zimmerman

Joint Program in Nuclear Medicine, Harvard Medical School,
Brigham and Women's Hospital, Children's Hospital, Dana Farber
Cancer Center and Beth Israel Hospital, Boston MA

12 December 1992

Herein are contained my personal thoughts and reflections upon
having returned from this year's RSNA meeting.

Motivation for attending

This year I attended the RSNA on the spur of the moment having
decided that there was too much going on at this year's RSNA in
the area of PACS and networking to ignore.  We are planning to
improve our software and hardware which is currently running in a
multi-vendor multi-modality Ethernet environment.  In particular
we are looking for a high quality color printer that will accept
a variety of formats and connect directly to the department
Ethernet.  My perspective is that of a physicist-engineer based
in nuclear medicine.  I attended from late afternoon of Monday 30
Nov to late afternoon of Wednesday 2 Dec.

Preliminary observations

The RSNA this year is more mind numbing than previous years, if
that is possible.  The technical exhibits, scientific exhibits,
refresher courses, scientific sessions and infoRAD are spread
over 3 floors of two buildings separated by about a kilometer
walkway.  A bus or taxi ride between the buildings takes 10-15
minutes.  This meeting is HUGE! 

By a stroke of good luck, or, probably great planning on the part
of the program committee, members of the AAPM received a copy of
the full program the week before the RSNA convened.  The airplane
ride and the elevated ride into the city was profitably spent
trying to make sense out of the complex program.

The amazing thing I found is the overall quality of the meeting
is probably better, at least equivalent to, previous years.  It
is a tribute to the planning and organizational skills of the
RSNA team that makes this meeting work.  Congratulations are in
order.

The only negative items I can think of are that I always seemed
to be in the wrong building and, for a period of 45 minutes
Tuesday morning, there was no power in the portion of the city of
Chicago that includes McCormick Place.  Only detriment to the
meeting seemed to be the refresher courses for that morning were
half-completed and a few computers that did not come up properly
when the power came back on about 10 AM.

Refresher Courses

The refresher courses had something for everyone.  There was a
heavy emphasis on continuing courses that spread over several
days and explored a topic at depth.  In addition there were 2
Categorical Courses and a Special Course on Computers for Clini-
cal Education in Radiology.  It was this latter course that I
attended.  

It was organized and presided over by Edward V. Staab, MD and
Janice C. Honeyman, PhD of Gainsville.  It was quite an ambitious
undertaking, meeting for a total of 12 hours throughout the week. 
There is a syllabus of this course available for $25. 

This Special Course on Computers for Clinical Education in
Radiology (Course No. 426) on Tuesday morning was subtitled
Clinical Applications of Computers.  David Gur, Pittsburgh ,
presented a survey, Requirements of Digital Imaging, concentrat-
ing on requirements at the workstation from the users perspec-
tive.  Elliot Fishman, Baltimore, was presenting an excellent
discussion entitled Advanced Image Processing when the lights
went.  The outage was due to a problem at a sub-station in
Chicago and took 45 minutes to get the power back.

Course No. 526, next in the series was on Wednesday morning and
subtitled PACS-Communications.  Brent Stewart, Los Angeles,
presented: Network Topologies, Media and Routing Protocols.  The
syllabus contains 16 pages covering this talk.  May be worth the
$25 for the syllabus.  Steven Horii, Washington, presented:
Network and ACR-NEMA Protocols.  He gave an eloquent dissertation
on how ACR-NEMA/DICOM fits into the larger world of network
protocols.  This observer got the impression that while ACR-NEMA
is at the cutting edge of network communication protocols it may
be too much too late.  It has taken just too long to have any
impact and there are other protocols that could supplant it.  The
ACR-NEMA hardware standard is certainly dead.  It was mentioned
only in off-hand comments at this meeting.

Sam Dwyer, Los Angeles, presented a survey: Wide-Area Network
Strategies, bringing into focus the costs associated with telera-
diology.  

Other attendees stated that this course in the early part of the
week was very mixed in quality, either too detailed or too wide
ranging.  I thought that these mid-week sessions were very good.

Scientific Sessions

Tuesday Afternoon - Room L-1 Physics (MR: Stereotaxic)

This session had 3 papers dealing with distortions in MRI imag-
ing.  Only one (No. 717: Design of a New 3D Geometric Distortion
Phantom for MR Imaging, ML Kessler, PL Carson, TL Chenevert, RK
Ten Haken of Ann Arbor) addressed the problem in a straightfor-
ward manner.  They described a 3D phantom made of 44 Lucite rods
with helical groves cut on them.  Accuracy of the error determi-
nations was better than 1.0 mm.  During the discussion it was
pointed out that this air filled phantom did not address the
position errors due to susceptibility effects.

Wednesday Morning - Evers Nuclear Medicine (Brain)

No. 763: Value of Tl-201 Imaging in Cerebral Lesions: Emission CT
with Autoradiography. K Maier-Hauff, GS Barzen, H Gottschalk of
Berlin.
These authors claimed that Tl-201 was able to differentiate
between high vs low grade tumors and also differentiate between
residual tumor and recurring tumor vs necrosis and scarring.  The
autoradiography using phosphor plates allowed further refinement
of the location of the thallium in the surgical specimens al-
though no information was gained about whether the distribution
was intra- or extra cellular.  

No. 769C: Spect Imaging of Brain Tumors with Tc-99m MIBI. B
Bagni, R Tamarozzi, F Calzolari, S Ceruti, L Pinna of Ferrara.
In this condensed 6 minute paper these investigators reported
that MIBI could substitute for Tl-201 but agreed choroid plexus
uptake and the ability to pickup low grade tumors were problems.

No. 771: Registration of Tl-201 SPECT and PET Images with MR
Images in Patients with Primary Brain Tumors.  HA Macapinlac, AM
Scott , J Zhang, H Kalaigian CI Caluser, RL DeLaPaz of New York
Using the Pelizzari software for registration these authors
concluded that the more accurate localization and characteriza-
tion of brain tumors resulted.   The registration process took 1
hour after all the data was present.  Registration accuracy was
thought to be 2-3 mm.  They also raised the tantalizing idea that
Tl-201 may be better that FDG for tumor characterization. 

Wednesday Morning - Room 1 Physics (Nuclear Medicine)

No. 875:  Mainframe Image Processing Speed Achieved in Personal
Computers with Memory-Intensive Algorithms  JP Pratt, JL Lear, of
Denver  
By trading increased programming complexity and more memory these
authors were able to speed up convolution, interpolation and
filtering operations by an order of magnitude.  The major strate-
gy was to use precomputed look-up tables instead of time expen-
sive machine instructions.  The resulting code was very machine
specific.

No. 876 Correlation of SPECT and MR Images of the Cerebral
Cortex: Finite Resolution Effects.  JR Gault, KJ Kearfott, PA
Hudgins, TL Wilson, TH Fox,forg NP Alazraki of Atlanta.
Using primarily a single slice Hoffman phantom and a simulated
SPECT image derived from the MR image the authors pointed out the
necessity of knowing the anatomy when reading brain perfusion
images.  They made a very convincing case for image registration.

No. 877C: Correction of Count-Rate Errors in Simultaneous Emis-
sion-Transmission CT.  BH Hasegawa, TF Lang, JK Brown, EL Gingold
of San Francisco.
The combination CT-ECT scanner using a Ge detector needs correc-
tion for pile-up errors produced during the dual imaging process. 
Analytic corrections were shown to help but compensating filters
and lower count rates will also be investigated.

No. 878C: Transmission CT of the Head with a SPECT System
Equipped with a Collimated Line Source and a Fan-Beam Collimator. 
BJ Kemp, FS Prato, L Reese of London, Ontario
These authors reported on their progress with a Monte Carlo aided
design of a SPECT camera transmission system.  They intend that
the final system will be able to provide CT images of sufficient
quality to allow accurate attenuation correction of SPECT brain
images.  But just how useful will poor quality CT images be when
the real anatomical images are available in another part of the
hospital?

No. 879C: Monte-Carlo Determination of Dual-Energy-Window Multi-
plier Required for Tc-99m Scatter Correction.  KF Koral, J Luo, X
Wang, CE Floyd, RJ Jaszczak, M Ljungberg of Ann Arbor.
This paper lays to rest any hope someone may have had that the
simple two window SPECT acquisition and subtraction of a fraction
of the scatter window from the photopeak window will permit good
scatter correction.  They show that the fraction to be subtracted
is a strong function of depth and surrounding activity.  It is
time to look critically at other methods.

Scientific Exhibits and infoRAD

The scientific exhibits were rather closely integrated with the
highly promoted infoRAD demonstration area.  In addition to the
more traditional poster and viewbox exhibits there was a consid-
erable number of computer based exhibits that were placed on the
periphery of the infoRAD area.  Some were quite good.   Those
that caught my attention are described below.

The centerpiece of the infoRAD area was the demonstration of the
ACR-NEMA style exchange of image files.  The Mallinkrodt at
Washington University helped to put this exhibit together.   A
large number of companies demonstrated that they could send,
receive and redisplay their own files after being stored on an
intermediate node.   Most of the participants also demonstrated
the ability to get 'foreign' image files from the intermediate
node and display them.  Real compatibility issues beyond just
display were not addressed.   Active transfer between participat-
ing companies were not addressed.   

I guess it is a start but so many of us have gone so much further
while waiting for industry to catch up that it all was sort of
ho-hum.  I still maintain that the ACR-NEMA interchange format
(since 1985) has been an industry sponsored delaying tactic to
avoid the real issues of data exchange.  And to think that some
of us 'users' helped in this delay.  Well, hindsight is always
easier than foresight.

Other items of interest at infoRAD were the 3 theaters with
nearly continuous presentations from industry.  Many presenta-
tions were performed several times during the week.  Unfortunate-
ly the presentation I was most interested on 'ACR-NEMA Standard
and Nuclear Medicine' by R. Roman never actually happened.  I
tried twice.  None of the others held enough interest to tear me
away from the other attractions of the meeting.

The rest of infoRAD was divided into exhibits in the following
categories: Literature Searches, Computer aided Instruction,
Videodisks and New Technologies and Radiology Workstations and
Internet.  Oh yes, there was an elaborate virtual reality demon-
stration that convinced me that not much will come of the ap-
proach demonstrated here.

The quality of the exhibits varied greatly.  A few that got above
my threshold are described below.

SPACE 9404: High-Speed Network (Local Area, Wide Area) Support
for Electronic Radiology. GJ Blaine, JR Cox, RG Jost of St. Louis
This exhibit demonstrated a broadband ATM (asynchronous transfer
mode) network switch for use in a local area environment telera-
diology application.

SPACE 9503:  OSIRIS: A Multiplatform, Multiomodality Imaging
Software. O Ratib, Y Ligier, C Girard, R Perrier, M Logean, JF
Vurlod of Geneva.
These people had a big presence.  A booth in infoRAD, flashly
brochures and frequent presentations in the infoRAD theaters. 
They seemed to be everywhere.  What they had was medical imaging
software that was platform independent and followed industry
standards.  It is "non commercial software" and can be obtained
free to medical institutions and universities.  Hard to beat
that.

SPACE 11-002:  A True 3D Atlas of the Human Skull and Brain.  KH
Hoehne, W Lierse, T Schiemann, R Schubert, M Riemer, U Tiede of
Hamburg
A truly interesting exhibit showing software that would be a
great teaching and diagnostic aid.  Christened "VOXEL-MAN/brain",
the atlas permits sectioning, dissection, identification etc. of
color coded parts of the brain on a realistic display using a
UNIX/Motif workstation.

SPACE 10-007:  Experimental Variables Affecting LSF Measurements
and Associated Frequency Descriptors: Simulation and Experimental
Study.  MF D'Souza, SM Mohapatra, JR Prince, JD Turley, JC
Leonard, DA Wilson of Oklahoma City
This exhibit, while presenting nothing new gave a very good
review of all the factors affecting the measurement of LSF in
imaging systems.

SPACE 10-26: 3DVIEWNIX: A Data-, Machine-, and Application-
independent Open Software System for the Visualization and
Analysis of Multidimensional, Multimodality Medical Images.  JK
Udupa, D Odhner, S Samarasekera, RJ Goncalves of Philadelphia
This exhibit was demonstrating an interesting software program
for viewing 3D medical data sets.  It is platform independent,
uses industry standards and their own multidimensional general-
ization to the ACR-NEMA standards.  The software will eventually
be released for others to use.

Technical Exhibits

There is no way I can adequately describe everything I saw and
looked at in the technical exhibit area.  The following is very
selective description of what grabbed me the most.  

Computer companies (real computer companies, that is) exhibiting
included Hewlett Packard, Sun and Digital.  Mostly they dem-
onstrated application programs, both commercial and academic. 
Notable was the fusion program from Marilyn Noz and Chip Maguire
and the Analyze program from Mayo in the Sun booth.  Also fea-
tured was application software developed for MRI segmentation and
surgery planning from the Surgical Planning Lab of the Radiology
Department of Brigham and Women's Hospital.

Digital was allowing Nynex to demonstrate their multimedia
physicians console/workstation for teleradiology in their booth. 

IDX is the company that took over DECrad from Digital.  They had
a large booth and were allowing other parties to demo software. 
In particular two packages from Brigham and Women's Hospital were
being shown.  A group that I work with was showing their improved
image registration software for SPECT, MRI and CT brain work. 
Newest feature is an integrated environment where contouring,
fitting and image review are performed from the same window. 
Using the fast graphics capability there is improved feedback on
the local fitting errors to assist in proper contouring.  Most
patients registrations can be performed within 10 minutes by a
skilled operator.  We are anxious to port it to the Alpha which
is coming real soon.  Also from the same hospital was a demo of
how DECrad can be linked to a digital image archive.  One depart-
ment database (DECrad) can be extended to serve as the entry into
the PACS archive.  Very nice.

Color Printers

I was interested only in color printers that were networkable. 
They had to be capable of readily connecting to an Ethernet and
the more image formats supported the better.  What follows is a
listing of features and opinions.  No guarantees of accuracy. 
Almost certainly there are omissions.  I would appreciate being
advised of other vendors' products.  Parallel ports and serial
ports, while in theory capable of networking, in practice the
expertise and trouble necessary to accomplish the job rule out
serious consideration, for me.

Mitsubishi had several booths.  The booth of their Professional
Electronics Division had only analog color printers to show. 
However another division, Mitsubishi International Corporation
was pushing the Shinko CHC-S446i ColorStream/DS.  It is of the
dye sublimation type, cost about $12K and supports parallel, RS-
232, Appletalk and SCSI inputs simultaneously.  It speaks a
Postscript compatible dialect as well as some other formats.  It
will have an Ethernet port soon.

Panasonic's lone digital printer is only speced at 203 dpi and
has only a parallel port.  It does knows Postscript and some
other formats.

Sieko was exhibiting two color printers that met the cut.  The
Professional Color Point used dye sublimation technology, con-
nected to Appletalk or to Ethernet with an adapter box and spoke
Postscript II. List price is $11,999.  The CH4104 listed for
$3999 also could do Appletalk and Postscript.   Both printers are
300 dpi but the image quality is notably better on the more
expensive printer with much better continuous color representa-
tion.

Sony was showing the UP-D7000 Digital Color Printer selling for
$11-12K.  Unfortunately it only comes with a SCSI port which
complicates the networking situation.
     
I did not see Tektronix at this meeting but I will not hold that
against them.  I obtained information on 3 digital printers from
Tektronix immediately after the meeting.  They use 3 different
technologies and they all seem to work very well judging from the
samples sent.  Prices range from $5000 to $10,000.  They provide
automatic switching between RS-232, parallel, Appletalk and
optional Ethertalk inputs.  The printers can be made to speak
TCP/IP also.  All of the printers know Postscript.  The best
images (publication quality) are with the Phaser IISD which uses
dye sublimation technology at 300 dpi.

I did not make it to the Kodak booth so do not know if they were
showing the Model 7720 digital color printer.  We have 2 of these
in operation at one of our hospitals.  They make beautiful
pictures but are very costly.

3M was showing a Color Laser Imager which used wet chemistry,
performed at 176 images per hour, worked off of Ethernet and cost
only $125K.  It handled a variety of film sizes, produced both
prints and transparencies.  Unfortunately is also requires
venting and handling of hazardous chemicals like any standard
film processor.

At one of the booths I ran into a representative from Apunix
Computer Services.  This company is able to perform system
integration services such as writing drivers, matching color
printers to your instruments and network etc.   In particular,
they had used Mitsubishi, Sharp and JVC color printers on Ether-
net. This may be an attractive way to get the job done.

Perhaps the most satisfactory solution is that provided by a
company from northern Ohio called Codonics.   They have a Mitsu-
bishi print engine imbedded into a system that contains a Unix
box, a hard disk spooler, and understands more that 20 formats. 
This comes complete with an Ethernet interface for about $13K.  
Unfortunately it is only about 160 dpi, not a limitation for most
images but may limit sharpness of alphanumerics.

A few observations on digital color network printers

Dye sublimation technology is well recognized to give the best
continuous tone color images.  Other technologies seem to achieve
colors by something akin to the half-tone process used by newspa-
pers for black and white images.  There is an obvious graininess
to color images associated with all the technologies except the
dye sublimation printers.  Expect these type of printers to cost
upwards of $9000.  Kodak has a very nice networkable printer that
is too expensive and knows a limited number of protocols.  It
does not seem to have good spooler capability either.  One
solution I have seen was to add an external MacIntosh as a front
end.  Tektronix offers a very nice solution but their printers
know only Postscript.  External disks for spooling are available. 
I like the system from Codonics the best right now and the price
is within reason considering that there is an internal computer,
disk and many formats are understood. 

Nuclear Medicine Cameras and Computers

Toshiba was exhibiting a 2-head SPECT system and their brand new
Sun based acquisition and processing system.  They have thrown
out the Tosbac computer of recent memory.  There are 12 of the
new computer systems in use.  It uses Xwindows, Motif and other
standards.  Costs about $70K.

General Electric had their Optima camera with the detectors at
right angles in the booth.  I was more interested the nuclear
medicine networking part of the exhibit.  It seems that GE is
linking with other product distributors to improve the utility of
their networking and "open system" ideas.  A company called Data
Medical, in the GE booth, was presenting their system integration
capabilities.  This took the form of Evergreen Technologies'
MedVision with GE's connectivity products: P-Link for IBM PCs, M-
Link for MACs and U-Link for Unix machines.  They were also in a
position to install other network peripherals and provide train-
ing in the use of the network.  Seems like a great idea that GE
is admitting that there are some better ideas that do not come
from GE.  The only downside is that it all seems terribly expen-
sive.  GE was also showing the Star 4000i which is the same old
STAR computer but with an Intel 860i added to speed up some
operations.

ADAC had a new dual head camera with heads shaved so that they
could fit tightly together at 90 degrees.  Sort of a large field
version of the GE Optima camera.  In full production by June at
$650K.  They also were making color prints on a Sieko CH 5404
printer.  It appeared to be make prints of lower quality.

Questions 

Is this business about right angled detectors proving useful? 
Are their any edge effects that interfere in real patients?  Has
it been used successfully in brain as well as heart imaging?  How
many real users of this technology are there?

-- 

Trevor Cradduck,                |  Voice: (519) 667-6574     
Department of Nuclear Medicine, |  FAX: (519) 667-6734
Victoria Hospital,              |  
University of Western Ontario,  |  E-mail: cradduck@uwo.ca
LONDON,  Ontario,               |  
Canada,  N6A 4G5                |