3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantification
Abstract Background Validation of threshold-based PET segmentation and PET quantification is typically performed with fillable phantoms. Theoretical considerations show that the inactive walls of the phantom cavities introduce a contrast dependence of the volume-reproducing threshold (VRT), potentia...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2025-06-01
|
| Series: | EJNMMI Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s40658-025-00768-x |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849725119699615744 |
|---|---|
| author | Adrian Jun Zounek Nico Maximilian Joerg Felix Lindheimer Artem Zatcepin Giovanna Palumbo Rosel Oos Astrid Delker Franz Josef Gildehaus Andreas Bollenbacher Guido Boening Peter Bartenstein Matthias Brendel Nathalie Lisa Albert Sibylle Ziegler Lena Kaiser |
| author_facet | Adrian Jun Zounek Nico Maximilian Joerg Felix Lindheimer Artem Zatcepin Giovanna Palumbo Rosel Oos Astrid Delker Franz Josef Gildehaus Andreas Bollenbacher Guido Boening Peter Bartenstein Matthias Brendel Nathalie Lisa Albert Sibylle Ziegler Lena Kaiser |
| author_sort | Adrian Jun Zounek |
| collection | DOAJ |
| description | Abstract Background Validation of threshold-based PET segmentation and PET quantification is typically performed with fillable phantoms. Theoretical considerations show that the inactive walls of the phantom cavities introduce a contrast dependence of the volume-reproducing threshold (VRT), potentially leading to segmentation errors and therefore miscalculations of target volumes. The goal of this study was to experimentally show the contrast independence of the VRT when using wall-less phantoms. Results Radioactive spheres were produced according to NEMA specifications (D = 10/13/17/22/28/37 mm) using a stereolithographic (SLA) 3D printer. For comparison, hollow spheres were filled with a similar activity concentration. Image data from both sphere types were acquired with five different signal-to-background ratios (SBR = 2/4/6/8/10) using a Siemens mCT 20 and a Biograph 64 TruePoint PET/CT system. Results from wall-less and fillable spheres were compared to evaluate contrast dependence and segmentation accuracy based on VRT and intensity profiles. Wall-less phantoms demonstrated consistent VRT values, with a coefficient of variation of 2% over all SBRs, indicating independence from contrast. Conversely, fillable phantoms exhibited significant VRT variability, with a coefficient of variation (CV) of 9% over all SBRs and up to 40% volume overestimation at low contrast. Additionally, activity distribution in the printed spheres was evaluated using PET-based statistical analysis and autoradiography. The PET intensity distribution in the printed material was highly uniform (CV = 4.2%), with a Kullback–Leibler divergence near zero and no statistically significant difference to the fillable spheres. Autoradiography revealed microscopic regions with elevated counts, showing a CV of 11.7%, which was effectively reduced to 2.4% after Gaussian filtering. Conclusions The theoretical predictions of a significant influence of inactive walls in low-contrast images and contrast-independent VRT in wall-less phantoms were successfully confirmed. SLA 3D printing of phantoms is a promising method for the reliable evaluation of PET quantification methods, particularly in low-contrast scenarios commonly encountered in clinical settings. |
| format | Article |
| id | doaj-art-6fceeda37ec14788b4e86aaa6fe37170 |
| institution | DOAJ |
| issn | 2197-7364 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | EJNMMI Physics |
| spelling | doaj-art-6fceeda37ec14788b4e86aaa6fe371702025-08-20T03:10:32ZengSpringerOpenEJNMMI Physics2197-73642025-06-0112111210.1186/s40658-025-00768-x3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantificationAdrian Jun Zounek0Nico Maximilian Joerg1Felix Lindheimer2Artem Zatcepin3Giovanna Palumbo4Rosel Oos5Astrid Delker6Franz Josef Gildehaus7Andreas Bollenbacher8Guido Boening9Peter Bartenstein10Matthias Brendel11Nathalie Lisa Albert12Sibylle Ziegler13Lena Kaiser14Department of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichDepartment of Nuclear Medicine, LMU University Hospital, LMU MunichAbstract Background Validation of threshold-based PET segmentation and PET quantification is typically performed with fillable phantoms. Theoretical considerations show that the inactive walls of the phantom cavities introduce a contrast dependence of the volume-reproducing threshold (VRT), potentially leading to segmentation errors and therefore miscalculations of target volumes. The goal of this study was to experimentally show the contrast independence of the VRT when using wall-less phantoms. Results Radioactive spheres were produced according to NEMA specifications (D = 10/13/17/22/28/37 mm) using a stereolithographic (SLA) 3D printer. For comparison, hollow spheres were filled with a similar activity concentration. Image data from both sphere types were acquired with five different signal-to-background ratios (SBR = 2/4/6/8/10) using a Siemens mCT 20 and a Biograph 64 TruePoint PET/CT system. Results from wall-less and fillable spheres were compared to evaluate contrast dependence and segmentation accuracy based on VRT and intensity profiles. Wall-less phantoms demonstrated consistent VRT values, with a coefficient of variation of 2% over all SBRs, indicating independence from contrast. Conversely, fillable phantoms exhibited significant VRT variability, with a coefficient of variation (CV) of 9% over all SBRs and up to 40% volume overestimation at low contrast. Additionally, activity distribution in the printed spheres was evaluated using PET-based statistical analysis and autoradiography. The PET intensity distribution in the printed material was highly uniform (CV = 4.2%), with a Kullback–Leibler divergence near zero and no statistically significant difference to the fillable spheres. Autoradiography revealed microscopic regions with elevated counts, showing a CV of 11.7%, which was effectively reduced to 2.4% after Gaussian filtering. Conclusions The theoretical predictions of a significant influence of inactive walls in low-contrast images and contrast-independent VRT in wall-less phantoms were successfully confirmed. SLA 3D printing of phantoms is a promising method for the reliable evaluation of PET quantification methods, particularly in low-contrast scenarios commonly encountered in clinical settings.https://doi.org/10.1186/s40658-025-00768-xSegmentationPhantoms3D printingPET |
| spellingShingle | Adrian Jun Zounek Nico Maximilian Joerg Felix Lindheimer Artem Zatcepin Giovanna Palumbo Rosel Oos Astrid Delker Franz Josef Gildehaus Andreas Bollenbacher Guido Boening Peter Bartenstein Matthias Brendel Nathalie Lisa Albert Sibylle Ziegler Lena Kaiser 3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantification EJNMMI Physics Segmentation Phantoms 3D printing PET |
| title | 3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantification |
| title_full | 3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantification |
| title_fullStr | 3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantification |
| title_full_unstemmed | 3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantification |
| title_short | 3D printing of radioactive wall-less PET phantoms improves threshold-based target delineation and quantification |
| title_sort | 3d printing of radioactive wall less pet phantoms improves threshold based target delineation and quantification |
| topic | Segmentation Phantoms 3D printing PET |
| url | https://doi.org/10.1186/s40658-025-00768-x |
| work_keys_str_mv | AT adrianjunzounek 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT nicomaximilianjoerg 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT felixlindheimer 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT artemzatcepin 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT giovannapalumbo 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT roseloos 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT astriddelker 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT franzjosefgildehaus 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT andreasbollenbacher 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT guidoboening 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT peterbartenstein 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT matthiasbrendel 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT nathalielisaalbert 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT sibylleziegler 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification AT lenakaiser 3dprintingofradioactivewalllesspetphantomsimprovesthresholdbasedtargetdelineationandquantification |