@article{WevrettFenwickScuffhametal.2018, author = {Wevrett, Jill and Fenwick, Andrew and Scuffham, James and Johansson, Lena and Gear, Jonathan and Schl{\"o}gl, Susanne and Segbers, Marcel and Sj{\"o}green-Gleisner, Katarina and Soln{\´y}, Pavel and Lassmann, Michael and Tipping, Jill and Nisbet, Andrew}, title = {Inter-comparison of quantitative imaging of lutetium-177 (\(^{177}\)Lu) in European hospitals}, series = {EJNMMI Physics}, volume = {5}, journal = {EJNMMI Physics}, doi = {10.1186/s40658-018-0213-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-233658}, year = {2018}, abstract = {Background This inter-comparison exercise was performed to demonstrate the variability of quantitative SPECT/CT imaging for lutetium-177 (\(^{177}\)Lu) in current clinical practice. Our aim was to assess the feasibility of using international inter-comparison exercises as a means to ensure consistency between clinical sites whilst enabling the sites to use their own choice of quantitative imaging protocols, specific to their systems. Dual-compartment concentric spherical sources of accurately known activity concentrations were prepared and sent to seven European clinical sites. The site staff were not aware of the true volumes or activity within the sources—they performed SPECT/CT imaging of the source, positioned within a water-filled phantom, using their own choice of parameters and reported their estimate of the activities within the source. Results The volumes reported by the participants for the inner section of the source were all within 29\% of the true value and within 60\% of the true value for the outer section. The activities reported by the participants for the inner section of the source were all within 20\% of the true value, whilst those reported for the outer section were up to 83\% different to the true value. Conclusions A variety of calibration and segmentation methods were used by the participants for this exercise which demonstrated the variability of quantitative imaging across clinical sites. This paper presents a method to assess consistency between sites using different calibration and segmentation methods.}, language = {en} } @article{WernerMarcusSheikhbahaeietal.2018, author = {Werner, Rudolf A. and Marcus, Charles and Sheikhbahaei, Sara and Solnes, Lilja B. and Leal, Jeffrey P. and Du, Yong and Rowe, Steven P. and Higuchi, Takahiro and Buck, Andreas K. and Lapa, Constantin and Javadi, Mehrbod S.}, title = {Visual and Semiquantitative Accuracy in Clinical Baseline 123I-Ioflupane SPECT/CT Imaging}, series = {Clinical Nuclear Medicine}, volume = {44}, journal = {Clinical Nuclear Medicine}, number = {1}, issn = {1536-0229}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168181}, year = {2018}, abstract = {PURPOSE: We aimed to (a) elucidate the concordance of visual assessment of an initial I-ioflupane scan by a human interpreter with comparison to results using a fully automatic semiquantitative method and (b) to assess the accuracy compared to follow-up (f/u) diagnosis established by movement disorder specialists. METHODS: An initial I-ioflupane scan was performed in 382 patients with clinically uncertain Parkinsonian syndrome. An experienced reader performed a visual evaluation of all scans independently. The findings of the visual read were compared with semiquantitative evaluation. In addition, available f/u clinical diagnosis (serving as a reference standard) was compared with results of the human read and the software. RESULTS: When comparing the semiquantitative method with the visual assessment, discordance could be found in 25 (6.5\%) of 382 of the cases for the experienced reader (ĸ = 0.868). The human observer indicated region of interest misalignment as the main reason for discordance. With neurology f/u serving as reference, the results of the reader revealed a slightly higher accuracy rate (87.7\%, ĸ = 0.75) compared to semiquantification (86.2\%, ĸ = 0.719, P < 0.001, respectively). No significant difference in the diagnostic performance of the visual read versus software-based assessment was found. CONCLUSIONS: In comparison with a fully automatic semiquantitative method in I-ioflupane interpretation, human assessment obtained an almost perfect agreement rate. However, compared to clinical established diagnosis serving as a reference, visual read seemed to be slightly more accurate as a solely software-based quantitative assessment.}, subject = {SPECT}, language = {en} } @phdthesis{Janssen2023, author = {Janßen, Jan Paul}, title = {Capabilities of a multi-pinhole SPECT system with two stationary detectors for in vivo imaging in rodents}, doi = {10.25972/OPUS-32860}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-328608}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Molecular imaging of rats is of great importance for basic and translational research. As a powerful tool in nuclear medicine, SPECT can be used to visualize specific functional processes in the body, such as myocardial perfusion or bone metabolism. Typical applications in laboratory animals are imaging diagnostics or the development of new tracers for clinical use. Innovations have enabled resolutions of up to a quarter of a millimeter with acceptable sensitivity. These advances have recently led to significantly more interest in SPECT both clinically and preclinically. The objective of this thesis was to evaluate the performance of the new U-SPECT5/CT E-Class by MILabs with a dedicated ultra-high resolution multi-pinhole collimator for rats and its potential for in vivo imaging of rats. The unique features of the U-SPECT are the large stationary detectors and the new iterative reconstruction algorithm. In addition, compared to the conventional system, the "E-Class" uses only two detectors instead of three. First, the sensitivity, maximum resolution, and uniformity were determined as performance parameters. Thereafter, CNRs for different activity levels comparable to those of typical in vivo activities were examined. Finally, two example protocols were carried out for imaging with 99mTc-MIBI and 99mTc-HMDP in healthy rats to evaluate the in vivo capabilities. For this purpose, CNR calculations and an image quality assessment were performed. The focus was on image quality as a function of scan time and post-reconstruction filter across a wide range of realistically achievable in vivo conditions. Performance was reasonable compared to other systems in the literature, with a sensitivity of 567 cps/MBq, a maximum resolution of 1.20 mm, and a uniformity of 55.5\%. At the lower activities, resolution in phantom studies decreased to ≥1.80 mm while maintaining good image quality. High-quality bone and myocardial perfusion SPECTs were obtained in rats with a resolution of ≥1.80 mm and ≥2.20 mm, respectively. Although limited sensitivity remains a weakness of SPECT, the U-SPECT5/CT E-Class with the UHR-RM collimator can achieve in vivo results of the highest standard despite the missing third detector. Currently, it is one of the best options for high-resolution radionuclide imaging in rats.}, subject = {SPECT}, language = {en} }