The purpose of the study is to evaluate the physical performance of a Biograph mCT Flow R PET/CT system (Siemens Healthcare, Germany) and to. to fundamentally change how PET imaging is performed. Powered by Siemens’ revolutionary FlowMotion™ technology,. Biograph mCT Flow™ is the world’s first. Biograph mCT Flow with FlowMotion™ technology combines our standard- setting PET/CT with a unique system design that enables continuous motion of.
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No noticeable differences were found between the two systems. Nevertheless, the choice of the reconstruction parameters in our study for the evaluation of the image quality was based on biograhp NEMA NU2 standard that asks to use clinically relevant settings. Open in a separate window.
The CTM acquisition followed the sequential subsequently. The contrast values, background variability, and the accuracy of attenuation and scatter correction for the lung insert were evaluated with an in-house developed plug-in biograpy ImageJ U. All measurements were performed at the site of the clinical installation of the system between August and December The axial sensitivity profiles with the line source placed at the center of the FOV and cm radial offset are shown in Fig.
The advantage of the continuous bed motion is the increase of uniformity in the sensitivity profile across the axial FOV, biographh to the fact biograpj the density of lines of response LOR does not depend of their axial position as in the case of SS acquisitions [ 13 ]. For this acquisition protocol, planning and scanning are restricted by the fixed size of the detector array.
Biograph mCT Flow
All data were corrected for random coincidences, normalization, dead time losses, scatter, and attenuation. Accuracy of count losses and random corrections For this evaluation, the measurements acquired for the evaluation of the scatter fraction and count rate performance was used.
Image quality phantom hot spheres at the center of the axial FOV The calculated activities at the start of the second scan were 5. Time of flight in PET revisited. Effect of scan time on oncologic lesion detection in whole-body PET. This information can be used to significantly improve the image signal-to-noise ratio SNR of the reconstructed PET images, thus, allowing for better image quality and shorter acquisition times [ 89 ].
This is further supported by the findings of Braun and colleges [ 34 ] who showed increased noise in CTM acquisitions in comparison to SS acquisitions with equivalent numbers of true events. The evaluation of positron emission tomographs requires reproducible and reliable methods to allow the comparison of different systems using accepted measurement standards. The scatter fraction and NECR were determined as described in the NEMA NU standard [ 19 ] acquired using software tools provided by the manufacturer and evaluated using in-house software.
The future of hybrid imaging—part 2: These settings were selected to cover the same axial FOV in the same time as performed with the IQ phantom measurements. The count rate error evaluation was also slightly modified in the standard. The bladder was chosen to test for this issue as it contains a uniform activity concentration and therefore similar to the background compartment in the IQ phantom.
Similar to CT acquisitions, the FlowMotion acquisition system tracks the bed position in real time and stores this information in the listmode data file as a new tag for each coincidence event [ 20 ].
The CTM scans giograph acquired with a table speed of biogrxph. This can be attributed in part to the generation of Gibbs artifacts at the edge of the reconstructed object, which are particularly noticeable in smaller objects [ 2529 ]. Evaluation was done using in-house software. NEMA NU measurements All measurements were performed at the site of the clinical installation of the system between August and December Image contrast recovery values sphere-to-background of 8: Nevertheless, based on the findings of Molina-Duran and colleges, [ 33 ] not the entire increase in BG variability can be explained from the decrease in count density.
For an axial FOV excluding the low sensitivity regions at the axial endpoints of the scan range a hypothetical scan ibograph an unlimited number of bed positionsa 4-min acquisition per bed position corresponds to a table speed of 0. There were no visual differences in image quality of the patient scans Fig.
Biograph mCT – Siemens Healthineers Global
At the start of the first measurement, the activity of the point source was 0. The reconstructions of the bbiograph sections through the center of the spheres within the image quality phantom for SS and CTM mode are shown in Fig.
Our data indicate a similar performance of the PET components of the mCT Flow and its predecessor system, the mCT [ 6 ] with the residual differences being discussed below. All procedures performed in studies involving human participants were approved by the regional ethics committee and were in accordance with the Helsinki declaration.
In CTM, the table is moved continuously through the axial FOV of the scanner to acquire date of an extended scan range. The sphere-to-background ratio is 4: A second scan of the same region in CTM mode was acquired at a table speed of 0. The changes in bladder filling are caused by the bioraph between the scans.
Image quality results for 4: Fully 3-D PET reconstruction with system matrix derived from point source measurements. Based on the results of Armstrong [ 25 ], this difference would increase for the smaller spheres when TOF was included into the reconstruction algorithm.
The most significant difference between both standards bjograph the change of the positions of the point source for spatial resolution measurements. The background variability was between 2. However, this study was performed on a different system with an axial FOV of Central slice of the image quality phantom for sequential a and CTM b acquisition modes.
Whole-body images were compared visually by two experienced imaging specialists one nuclear medicine cmt and one imaging physicist.
Concept, acquisition bigoraph optimization and clinical application. The TOF measurement of two coincidence photons allows the localization of the positron annihilation point with a spatial accuracy that depends on the system timing resolution.
The elevated background variability is assumed to blograph caused by the choice of the table speed and the data processing techniques specific to CTM acquisitions. The patient handling system PHS contains a horizontal magnetic drive system that enables a continuous table motion with a positioning accuracy of less than 0.
The CTM FlowMotion technology requires a new design of the patient table and the acquisition electronics. The scatter fraction was calculated to be Thus, users may opt for applying PSF and other geometric corrections to the data, which inevitable makes inter-system comparisons more difficult. Published online Oct For the purpose of comparison between systems, this may not be sufficiently accurate.