An improved iterative thresholding method to delineate PET volumes using the delineation-averaged signal instead of the enclosed maximum signal.
Unlabelled: An improved thresholding method for segmentation of PET volumes is proposed that uses the delineation-averaged activity concentration (AC) within an iterative procedure instead of the enclosed maximum AC. Methods: The average-based iterative thresholding method (avg-ITM) needs the backgr...
| Publicado en: | Journal of Nuclear Medicine Technology Vol. 43; no. 1; pp. 28 - 36 |
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| Autor principal: | |
| Formato: | research Journal Article |
| Publicado: |
Society of Nuclear Medicine
Mar2015
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=109777684&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 109777684 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00914916 H7Q jtl: Journal of Nuclear Medicine Technology issn: 00914916 maglogo: N pubinfo: dt: Mar2015 vid: 43 iid: 1 pid: 2576 pub: Society of Nuclear Medicine place: Reston, Virginia artinfo: ui: 109777684 NLM25655341 2012925311 10.2967/jnmt.114.152678 NLM25655341 109777684 ppf: 28 ppct: 8 formats: fmt: @attributes: type: P tig: atl: An improved iterative thresholding method to delineate PET volumes using the delineation-averaged signal instead of the enclosed maximum signal. aug: au: Jentzen, Walter affil: Klinik für Nuklearmedizin, Universität Duisburg-Essen, Essen, Germany walter.jentzen@uni-duisburg-essen.de. sug: subj: Image Processing, Computer Assisted Methods Tomography, Emission-Computed Methods Abdominal Neoplasms Radiography Pilot Studies Human Observer Bias Phantoms, Imaging Reproducibility of Results Thyroid Neoplasms Radiography Tomography, X-Ray Computed Uncertainty ab: Unlabelled: An improved thresholding method for segmentation of PET volumes is proposed that uses the delineation-averaged activity concentration (AC) within an iterative procedure instead of the enclosed maximum AC. Methods: The average-based iterative thresholding method (avg-ITM) needs the background-corrected relative boundary-reproducing threshold (BRT) curve applied to segment the tumor. On the basis of a previous study, which developed an iterative thresholding method using the maximum AC (max-ITM), the average-based BRT curve was derived from the AC profiles of a sphere model. Numerous phantom scans (using glass spheres, wax spheres, and bihemispheres) under different conditions were obtained to verify and assess the avg-ITM. Clinically, the avg-ITM was tested in 2 patients bearing tumors, and the interobserver and intraobserver variability in the volume segmentation was assessed using 5 tumors analyzed by 5 observers. In the entire study, the max-ITM was also applied to compare the respective results. Results: The phantom measurements verified the average-based BRT curve and demonstrated that spheric tumors down to a diameter equaling the spatial resolution could be delineated. In contrast to the max-ITM, the avg-ITM yielded reliable volumes (within the 95% confidence intervals) for standardized uptake values and signal-to-background ratios larger than 3. The volumes derived using the max-ITM were significantly underestimated for object sizes with diameters considerably larger than the spatial resolution. Phantom measurements using bihemispheres with decreasing AC ratios demonstrated that the avg-ITM was robust down to an AC ratio of 0.5 and, therefore, is less prone to nonuniformity than the max-ITM, which was corroborated by real tumor imaging. The observer-related variability was small (mean absolute relative SD < 4%). Conclusion: Compared with the max-ITM, the avg-ITM improves the segmentation results for large objects and is less sensitive against image noise and nonuniformity. A clinical comparison study is warranted to assess the benefits of the avg-ITM method compared with other segmentation methods. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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