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.
|Published (Last):||14 August 2017|
|PDF File Size:||12.90 Mb|
|ePub File Size:||20.26 Mb|
|Price:||Free* [*Free Regsitration Required]|
Data were reconstructed with an ordered-subset expectation maximization OSEM [ 25 ] 3D iterative algorithm, using 2 iterations i and 24 subsets sand additionally with 2 iterations and 21 subsets applying PSF correction and TOF. Nevertheless, CTM enables the use of varying table speeds for different axial regions.
Maximum solid line and minimum dashed line relative count rate error for the different activity distributions.
Image contrast recovery values sphere-to-background of 8: NEMA NU measurements All measurements were performed at the site of the clinical installation of the system between August and December This information can be used to significantly improve the image signal-to-noise ratio SNR of the biorgaph PET images, thus, allowing for better image quality and shorter acquisition times [ 89 ].
Contrast recovery values as well as image quality obtained in SS and CTM acquisition modes were biograaph.
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 CTM FlowMotion technology requires a new design of the patient table and the acquisition electronics. Characterization of sampling schemes for whole body PET imaging. For this acquisition protocol, planning and scanning are restricted by the fixed size of the detector array. The first and the last slice of the acquisitions were excluded from this evaluation. 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 for ImageJ U.
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. No noticeable difference between the two systems was observed.
For resolution measurements, an 18 F point source inside a glass capillary tube was used. The system sensitivity was then boigraph as the ratio between the true count rate with no absorption and the starting activity.
Based on this relationship, a considerable decrease in detectability is expected when the acquisition time is reduced by a factor of 2, which is inevitably related to image contrast.
The advantage of the continuous bed motion is the increase of uniformity in the sensitivity profile across the axial FOV, due to the fact that the density biograpu lines of response LOR does not depend of their axial position as in the case of SS acquisitions [ 13 ]. For this evaluation, the measurements acquired for the evaluation of the scatter fraction and count rate performance was used.
Biograph mCT – Siemens Healthineers Global
The reconstructions of the transaxial sections through the center of the spheres within the image quality phantom for SS and CTM mode are shown in Fig. The expected value of the true count rate is gained by bioraph fit through all data below the peak NECR standard as opposed to the extrapolated values from the last three acquisitions standard.
Whole-body images were compared visually by two experienced imaging specialists one nuclear medicine physician and one imaging physicist. Schematic diagram of a step-and-shoot SS left and continuous right table motion CTM acquisition protocol.
Based on the results of Armstrong [ 25 ], this difference would increase for the smaller spheres when TOF was included into the reconstruction algorithm. National Center for Biotechnology InformationU.
This set of parameters should be defined by the vendor and be delivered with the system, e. For an axial FOV excluding the low sensitivity regions at the axial endpoints of the scan range a hypothetical scan with an unlimited number of bed positionsa biograpu acquisition per bed position corresponds to a table speed of 0.
No visual difference in overall PET image quality was observed by two experienced imaging experts. Fully 3-D PET reconstruction with system matrix biogrraph from point source measurements.
Therefore, the CTM acquisitions resulted in a lower number of collected true events than in SS mode, which in turn resulted in an elevated background variability [ 33 ]. A digital architecture for routinely storing and buffering the entire bit event stream at maximum bandwidth for every acquisition in clinical real-time 3-D PET: 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.
A similar increase was observed in blograph CVs which equate to the biogralh variability in the bladder of the two patients. In comparison, Marti-Climent et al. Small differences in local uptake e.
Biograph mCT 20 Excel
Axial sensitivity profile for the measurements with the line source in the center of the field of view and at cm radial offset. Within the SS protocol, the table is in a fixed position during an acquisition of data in the FOV and subsequently moves to the next position to acquire data of an axial range greater than the axial FOV of the system. Online random subtraction was applied from a delayed coincidence window.
Support Center Support Center. TOF information was not used in this measurement. Sensitivity The mCT Flow system had a sensitivity of 9. Discussion 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.
There were no visual differences in image quality of the patient scans Fig. The changes in bladder filling are caused by the time between the scans. Traditionally, whole-body PET examinations are performed in step-and-shoot SS mode, introducing the patient table motion between consecutive acquisitions of adjacent bed positions [ 1011 ].
All procedures performed in studies involving human participants were approved by the regional ethics committee and were in accordance with the Helsinki declaration.