SUV reproducibility on different reporting platforms

Transcription

1 SUV reproducibility on different reporting platforms DJ Towey, Imperial College / Northampton General J Taylor, Sheffield teaching Hospital NHS Trust J Cullis, University Hospitals Coventry and Warwickshire NHS Trust M Barnfield, Leeds Teaching Hospitals NHs Trust S Cade, Royal united Hospitals Bath K Carson, St Luke s Hospital Dublin D Hall, Bristol Royal Infirmary B Kenny, Link Medical Ltd E O Shaughnessy, Poole Hospital NHS Foundation Trust D White, Barnsley Hospital AW Murray, Sheffield teaching Hospital NHS Trust IPEM NM Software Quality Group

2 What is SUV? SUV = %&/() *%&/*+ Image data Injected Patient activity weight SUVmax = maximum in ROI / image - sensitive to noise SUVmean= average in ROI/VOI - sensitive to ROI/VOI size SUVpeak= average in standard sized VOI Other scaling factors SUV: Scaled to Lean Body Mass, BSA, glucose

3 Aims To audit NM/PET reporting software in the following areas: Test of orientation / alignment SUV consistency (using SUV-max no operator variability) Transverse = Sagittal = Coronal Does including a CT make any difference? Effect of CT slice thickness

4 Method Three phantoms scanned on three clinical PET- CT scanners total of 12 datasets

5 Method

6 Audit pass criteria Orientation known from acquisition SUV consistency: Use mode of results as gold standard Manually calculated SUVmax using DICOM tags only Different levels of quoted precision (1-5 decimal places) and rounding errors/differences Quoted precision or 1%, Whichever greater as allowed error

7 Reporting/analysis platforms Vendor Software package Notes GE Volumetrix for Xeleris 2 Use original or Use Displayed options GE Volumetrix for Xeleris 3 Use original or Use Displayed options GE AW (Advantage Workstation) V4.6 Hermes Volume fusion Unix based Hermes Hybrid Viewer MS-Windows based MIM MIRADA MIM XD Advanced Osirix Osirix Only research versions tested FDA approved version also available

8 Reporting/analysis platforms Vendor Software package Notes Philips EBW Multipleversions tested Siemens TrueD On reporting workstations Siemens 3dViewer On acquisition stations Siemens MS viewer Siemens Syngo-Via (results from Manufacturer) Fusion Viewer ImageJ MiPAV Only quotes pixel values Only quotes pixel values Only quotes pixel values

9 Results All software interpreted the orientation tags correctly OSIRIX didn t automatically go into radiographic orientation but did label correctly

10 Results SUV consistency

11 Displayed Image Original Data Raw data ~50x50 pixels

12 GE Healthcare GE- Advantage Windows (GE-AW workstation) Data imported correctly and results matched GE- Volumetrix for Xeleris 2 / Xeleris 3 Use original data vs Use displayed data Original data gives correct result on Transverse slice only Displayed data has been interpolated and therefore does not match the other vendors User prompted for input for non-ge data Injection date & time, residue activity date & time, for Siemens and Philips data

13 Not able to replicate the problem loading non-ge data The Volumetrix manual states that quantitative data should be taken from transverse slices only They recommend using the dedicated AW workstations for quantitative analysis

14 Hermes Medical Solutions Hermes Hybrid Display Data imported correctly and results matched Volume fusion display Last updated 2008, available on most Hermes installations When just PET data loaded- values from Transverse slices are correct Sagittal and coronal values are always different When PET and CT loaded together SUV results decrease

15 Calculation of SUVmax In order to improve the quantitative accuracy, the calculation of SUVmax in Hermes is derived from the original voxels of the PET data. The calculation is independent of any manipulation used for display purposes: no matter what manipulation is used for display, the original voxel data is always used for the SUVmax calculation. This improved method is implemented in Hermes Hybrid Viewer, which replaced the Hermes Classic application Volume Display. Volume Display is no longer current product and is being phased out. The calculation therefore differs between Hybrid Viewer and Volume Display, and this difference is explicitly described in the respective user manuals for these applications. Joakim Arwidson, Quality Manager

16 MIM Data imported correctly and results matched

17 Mirada- XD Data imported correctly and results matched

18 OSIRIX Data imported correctly and results matched Not automatically in radiographic mode

19 Philips - EBW Results tested on three installations of EBW software All three gave different results 2D and 3D viewing options 2D and 3D tools

20 It looks like the users have used the 2D ROI measurement tools on the EBW-NM to check the SUV values. When doing absolute comparisons we recommend using the 2D layout which displays the original transaxial data (this is documented). Alternatively I would always recommend using one of our 3D ROI measurement tools for looking at SUV values these obtain their values from the original slice data rather than the resampled slices they are placed in Joe Glenon, Philips

21 Siemens Healthcare TrueD Data imported correctly and results matched MSViewer Data imported correctly and results matched (Syngo-Via - Manufacturers results) Data imported correctly and results matched 3D Viewer Basic software available on many (?all) PET acquisition workstations Displays images as PET, Fused and in registration panels/windows- Different results in each panel

22 Siemens 3d viewer SUVmax = or or ? SUVmax mode result = 1.96

23 the 3D Viewer is not designed for such quantification, it is only a quick viewing tool. Applications like TrueD or syngo.via (MM Oncology) are the ones to use for quantification of PET image data. On the 3D Viewer, the quantification is derived from the screen pixel interpolated image rather than the stored image. That would explain also why the values differ when calculated from the native image and from the fused views as the pixel interpolation process is different. This application was designed for quick review. Jerome Declerck, Siemens

24 Summary of results All manufactures have a least one piece of software that can give the right answer The three scanner manufactures and Hermes all have at least one piece of software that can give the wrong answer (but most mention differences in the manuals) Variations of ~24% seen (even from same piece of software) Problems arising when quantitation is being done on resampled/interpolated data

25 Quantitative results agree on the following software: GE AW Hermes hybrid display MIM Mirada XD OsiriX Siemens TrueD Siemens MSviewer Be very careful how you use: GE volumetrix Hermes volume display Philips EBW Consider alternatives before using Siemens 3D viewer

26 Next stages Phantom images will soon available on NMSQG website for local testing SUV-peak, SUV-mean Digital phantom has been developed and will be available shortly

27 Thanks to.. My co-authors from the IPEM software SIG Laura Perry Imperial College Healthcare Allison Craig- Royal Marsden