Belohlavek, Otakar

Dostál, Martin

Hudec, Bohuslav

Janeba, Daniel

English

Via Medica Journals

59TechnicalnotesNuclear Medicine Review 2001 Vol. 4, No. 1, pp. 5960Copyright ' 2001 Via MedicaISSN 15069680www.nmr.viamedica.plMartin DostÆl1, Daniel Janeba2, Bohuslav Hudec1, OtakarBelohlavek21Department of Computer Science and Engineering, Faculty of ElectricalEngineering, Czech Technical University, Prague, Czech Republic2Department of Nuclear Medicine  PET Centre, Na Homolce Hospital,Prague, Czech RepublicReconstructed volume files and projection data resulting fromSPECT and PET scans can be viewed and evaluated only on theconsoles belonging to scanners or cameras. Re-evaluation of larg-er data sets resulting in clinical studies leads to consumption ofWBviewer  a way to seetomographic data on PCCorrespondence to: Dr. Daniel JanebaDepartment of Nuclear Medicine  PET CentreNa Homolce HospitalRoentgenova 2, 150 30 Prague 5, Czech RepublicTel: (+420) 2 5727 2169, fax: (+420) 2 5727 2163e-mail: Daniel.Janeba@homolka.czmachine time, which is very inconvenient in routine investigation.Similarly, to present data at conferences or to share the files amongspecialists for clinical discussions is also possible only at the con-soles. That is why PC viewers of different file formats and differentquality can be found on the Internet. The aim of this short commu-nication is to present a viewer designed for SPECT and PET wholebody tomographic imaging. The viewer was created to meet therequirements of the PET centre Prague but is free and can bedownloaded from http://www.homolka.cz/nm.The WBviewer offers all standard operations with the sliceslike setting thresholds, choosing colour table, choosing slices andcreating animation from projections, printing and saving picturesFigure 1. Screenshot of WBviewer.60Nuclear Medicine Review 2001, Vol. 4, No. 1www.nmr.viamedica.plTechnicalnotesas bitmaps (see the screenshot in Fig. 1). If the user has any favor-ite colour table, there is a colour table editor implemented for creat-ing user-accustomed colour tables. While the basic operations withthe slices are easy to understand for everyone dealing with nuclearmedicine, the projections might need some more explanation.To have some 3 dimensional imagination about the radio-pharmaceutical uptake in the body, so-called projections are cal-culated. The tomographic cube of data is projected along theparallel beam then rotated with a fixed angular step around thelong axis and projected again and so on. The result is a set ofprojections (see example in Fig. 2) which when animated will cre-ate a rotating body. This animation can give the physician thepossibility of better imagination of mutual positions of differentstructures. The advantage of this kind of viewing is clearly appar-ent by PET. We regularly use two methods implemented in ECATEXACT software v. 7.2  maximum intensity projection (MIP) andintegral intensity projection (II). The projections are calculated al-ready during the reconstruction and stored in a separate file. Thisway is faster for displaying but is more discspace-consuming.The presented WBviewer calculates the projections directlyfrom volume data. The projection method is up to you  ei-ther conventional MIP or II projection or weighted average pro-jections where the depth of the voxel in the patient body istaken into account (the voxel value is weighted with distanceor reciprocal distance) [1]. The calculated projections can besaved in an internal format and loaded again or the set ofprojections can be saved as bitmaps and animated usingcommercial software.The WBviewer was written in MS Visual Studio 6.0 using theMFC 4.2 libraries. It has been tested on MS Windows 95 andhigher. The input file formats of the viewer are Interfile 3.3 (test-ed on files from Hermes, Nuclear Diagnostics, Sweden) and ECATmatrix format (tested on CTI/Siemens software versions 7.x).References1. Wallis JW, Miller TR, Volume Rendering in Three-Dimensional Displayof SPECT Images. J Nucl Med 1991; 31: 14211430.Figure 2. Projections of whole body, angles from left: 0° (front projection), 30°, 60° and 90° (projectionfrom the right).

WBviewer ? a way to see tomographic data on PC

https://journals.viamedica.pl/nuclear_medicine_review/article/download/15478/12295

WBviewer ? a way to see tomographic data on PC

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