ABSTRACT
Odontome gelten zusammen mit den Amelo- blastomen als die häufigsten odontogenen Tumoren. Sie entstehen während der embryo- nalen Zahnkeimentwicklung durch fehlerhaft differenziertes Keimgewebe und werden daher auch als Hamartome bezeichnet. Somit sind sie also strenggenommen keine klassischen Neoplasien.
Subject(s)
Odontoma , Humans , Odontoma/surgery , Odontoma/diagnosis , Odontoma/pathology , Adolescent , Mandibular Neoplasms/surgery , Mandibular Neoplasms/pathology , Mandibular Neoplasms/diagnosis , Maxillary Neoplasms/surgery , Maxillary Neoplasms/pathology , Maxillary Neoplasms/diagnosis , Male , Diagnosis, Differential , FemaleABSTRACT
BACKGROUND: The aim of this study was to evaluate and compare PET image reconstruction algorithms on novel digital silicon photomultiplier PET/CT in patients with newly diagnosed and histopathologically confirmed lung cancer. A total of 45 patients undergoing 18F-FDG PET/CT for initial lung cancer staging were included. PET images were reconstructed using ordered subset expectation maximization (OSEM) with time-of-flight and point spread function modelling as well as Bayesian penalized likelihood reconstruction algorithm (BSREM) with different ß-values yielding a total of 7 datasets per patient. Subjective and objective image assessment with all image datasets was carried out, including subgroup analyses for patients with high dose (> 2.0 MBq/kg) and low dose (≤ 2.0 MBq/kg) of 18F-FDG injection regimen. RESULTS: Subjective image quality ratings were significantly different among all different reconstruction algorithms as well as among BSREM using different ß-values only (both p < 0.001). BSREM with a ß-value of 600 was assigned the highest score for general image quality, image sharpness, and lesion conspicuity. BSREM reconstructions resulted in higher SUVmax of lung tumors compared to OSEM of up to + 28.0% (p < 0.001). BSREM reconstruction resulted in higher signal-/ and contrast-to-background ratios of lung tumor and higher signal-/ and contrast-to-noise ratio compared to OSEM up to a ß-value of 800. Lower ß-values (BSREM450) resulted in the best image quality for high dose 18F-FDG injections, whereas higher ß-values (BSREM600) lead to the best image quality in low dose 18F-FDG PET/CT (p < 0.05). CONCLUSIONS: BSREM reconstruction algorithm used in digital detector PET leads to significant increases of lung tumor SUVmax, signal-to-background ratio, and signal-to-noise ratio, which translates into a higher image quality, tumor conspicuity, and image sharpness.
ABSTRACT
Angiosarcomas are rare aggressive neoplasms with a wide variety of anatomic locations, one third of them presenting multifocal. Molecular imaging with PET/CT and PET/MR plays an emerging role in staging sarcomas. This case demonstrates the value of PET/MR imaging of an angiosarcoma with involvement of the tibial head and a popliteal aneurysm with histopathologic correlation.
