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MINUTES-tcon
DICOM Working Group Eleven
(Display Function Standard)
November 5, 2014
Members Present
Philips Healthcare
Siemens Healthcare
Toshiba Visualization System NA
Represented by
Joe Luszcz
Andreas Klingler
Jonathan Whitby
Members Absent
Voting Representative
AIUM
*AAOMR
*American College of Radiology
*CARS
*FDA
*Panasonic
Web 3D Consortium
Thomas Nelson
Allan Farman
Alan Rowberg
Heinz Lemke
Kish Chakrabarti
Florian Knicker
N. Polys
Other Member Representatives and Observers Present
Luiza Kowalczyk
MITA/NEMA
Julien Erath
Siemens Healthcare
Elmar Seeberger
Siemens AG
Stephen Vastagh
MITA/NEMA
* Not counted toward quorum
Presiding Officer:
Secretary
Joe Luszcz, Co-Chair
Luiza Kowalczyk
1. Opening
The meeting was called to order at 08:00 (am) USA Eastern Time. The participants introduced
themselves. The antitrust rules were reviewed. The approval of the previous minutes was tabled. The
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WG-11 (Display Function Standard) of
The DICOM Standards Committee.
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November 05, 2014
purpose of this meeting is to discuss the Curved Straightened MPR supplement for First Reading.
1. SupXXX CurvedStraightened MPR
Members conducted a lengthy technical discussion regarding Curved Straightened MPR.
A.Klingler created and presented a Curved-Straightened-MPR-Diagram which was discussed in
details.
The document Curved-Straigthened-MPR Diagram.vsd is also posted in the ftp folder. The
main topics of the discussion was:

MPR Start Point (0070,xxx)

MPR Direction Vector (0070,xxx)

MPR View Width (00700,xxx)

MPR Slab Thickness

Finding a plane (tangent line was suggested and parallel approach to it)

View direction (which direction is pointing-rotation attributes)
2. Proposed Reference Algorithm for Straightened MPR
1) Refer to Andreas Klingler’s drawing
2) Reference plane defined by
a) MPR Width Direction
b) Vector tangent to curve at starting point
c) OPEN ISSUE: Whether to explicitly include a Starting Tangent Vector attribute
d) OPEN ISSUE: Should curve be defined to be in center of MPR view, or should an offset
attribute be added so the curve can be placed anywhere within the MPR view:
3) Start and end points of view specified as index values of points in the curve array
a) Unambiguous should the same (x,y,z) point exist more than once in the curve array
b) Faster to find the points in the array than by (x,y,z) searching
4) Distance along curve between start and end points is calculated, lines are equally spaced between
start and end points with the number of lines an implementation decision
5) Curve direction does not have to be vertical in the MPR View
a) Based on a View Rotation attribute value
i) UP:
Start point at bottom of MPR view, End point at top of MPR view
ii) RIGHT: Start point at left side of MPR view, End point at right side of MPR view
iii) DOWN: Start point at top of MPR view, End point at bottom of MPR view
iv) LEFT:
Start point at right side of MPR view, End point at left side of MPR view
b) Should we constrain to UP or RIGHT only?
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WG-11 (Display Function Standard) of
The DICOM Standards Committee.
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November 05, 2014
6) All MPR lines are defined to
a) Intersect the curve
b) Be perpendicular to the curve at the intersection point
c) Be parallel to the reference plane
7) Look direction
a) Right Hand Rule from Tangent vector to Perpendicular vector: i.e., looking down through the
view
8) Corner case: when curve becomes vertical to the reference plane
a) All lines perpendicular to curve are parallel to the reference plane
b) Define “neighbor” lines as the last line prior to the curve becoming vertical and the first line
just as the line deviates from vertical
c) General rule: Smooth rotation of lines in the vertical segment from neighbor lines
d) Ambiguity: Look direction should the line turn back towards the starting point direction as the
line deviates from vertical
i) If line turns back in the original direction: ok, look direction still down
ii) If line reverses direction, what to do???
HOMEWORK: Members should review the algorithms in use in their products to see if there are
any details that are not intellectual property and can be shared for the
standardized description of these views.
Members should also make it a priority to review open-source implementations
like Osirix, both to gain insight over that algorithm and also to compare to their
proprietary implementations to see if there is substantial agreement (and thus
validate it as a viable model for the standard parameteric description)
J. Luszcz will try to capture in text and drawings what they’ve defined so far
during today’s meeting
This group intends to present this draft supplement to WG-06, next week, for first reading.
3. Supplement 156
The Group has completed all revisions needed for the reading for Letter Ballot, next week, at
the WG-06 meetings.
2. Next Meetings
T-con(s) (all USA Eastern Time)

2014-11-07
07.00-09.00 (am)USA Eastern Time
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WG-11 (Display Function Standard) of
The DICOM Standards Committee.
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November 05, 2014
In-person

It was decided that in-person meetings will be held in conjunction with the WG-06 meetings
instead of at SIIM.
3. Adjournment
The t-con was adjourned 09:45am USA Eastern Time.
Submitted by Luiza Kowalczyk, Secretary
Reviewed by legal counsel, Clark Silcox
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WG-11 (Display Function Standard) of
The DICOM Standards Committee.
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November 05, 2014