Attenuation Correction and Quantitative PET Analysis

2021 ◽  
pp. 17-25
Author(s):  
Mario Serrano-Sosa ◽  
Ana M. Franceschi ◽  
Chuan Huang
Keyword(s):  
Attenuation Correction ◽  
Quantitative Pet

scholarly journals Machine learning in quantitative PET: A review of attenuation correction and low-count image reconstruction methods

2020 ◽  
Vol 76 ◽  
pp. 294-306
Author(s):  
Tonghe Wang ◽  
Yang Lei ◽  
Yabo Fu ◽  
Walter J. Curran ◽  
Tian Liu ◽  
...  
Keyword(s):  
Machine Learning ◽  
Image Reconstruction ◽  
Attenuation Correction ◽  
Quantitative Pet ◽  
Reconstruction Methods

scholarly journals Towards quantitative PET/MRI: a review of MR-based attenuation correction techniques

2008 ◽  
Vol 36 (S1) ◽  
pp. 93-104 ◽  
Author(s):  
Matthias Hofmann ◽  
Bernd Pichler ◽  
Bernhard Schölkopf ◽  
Thomas Beyer
Keyword(s):  
Attenuation Correction ◽  
Quantitative Pet

scholarly journals Quantitative PET/MR imaging of lung cancer in the presence of artifacts in the MR-based attenuation correction maps

2019 ◽  
Vol 61 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Samuel Kuttner ◽  
Martin Lyngby Lassen ◽  
Silje Kjærnes Øen ◽  
Rune Sundset ◽  
Thomas Beyer ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Mr Imaging ◽  
Attenuation Correction ◽  
Lung Tumor ◽  
Tumor Therapy ◽  
Standardized Uptake Value ◽  
Therapy Response ◽  
Susceptibility Artifacts ◽  
Quantitative Pet ◽  
The Impact

Background Positron emission tomography (PET)/magnetic resonance (MR) imaging may become increasingly important for assessing tumor therapy response. A prerequisite for quantitative PET/MR imaging is reliable and repeatable MR-based attenuation correction (AC). Purpose To investigate the frequency and test–retest reproducibility of artifacts in MR-AC maps in a lung cancer patient cohort and to study the impact of artifact corrections on PET-based tumor quantification. Material and Methods Twenty-five lung cancer patients underwent single-day, test–retest, 18F-fluorodeoxyglucose (FDG) PET/MR imaging. The acquired MR-AC maps were inspected for truncation, susceptibility, and tissue inversion artifacts. An anatomy-based bone template and a PET-based estimation of truncated arms were employed, while susceptibility artifacts were corrected manually. We report the frequencies of artifacts and the relative difference (RD) on standardized uptake value (SUV) based quantification in PET images reconstructed with the corrected AC maps. Results Truncation artifacts were found in all 50 acquisitions (100%), while susceptibility and tissue inversion artifacts were observed in six (12%) and 26 (52%) of the scans, respectively. The RD in lung tumor SUV was < 5% from bone and truncation corrections, while up to 20% RD was introduced after susceptibility artifact correction, with large inconsistencies between test–retest scans. Conclusion The absence of bone and truncation artifacts have limited effect on the PET quantification of lung lesions. In contrast, susceptibility artifacts caused significant and inconsistent underestimations of the lung tumor SUVs, between test–retest scans. This may have clinical implications for patients undergoing serial imaging for tumor therapy response assessment.

Myocardial perfusion scintigraphy in Germany

2007 ◽  
Vol 46 (02) ◽  
pp. 49-55 ◽  
Author(s):  
W. Burchert ◽  
F. M. Bengel ◽  
R. Zimmermann ◽  
J. vom Dahl ◽  
W. Schäfer ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
Myocardial Perfusion ◽  
Attenuation Correction ◽  
Working Group ◽  
Primary Care Physicians ◽  
Gated Spect ◽  
Myocardial Perfusion Scintigraphy ◽  
German Society ◽  
University Hospitals ◽  
Perfusion Scintigraphy

SummaryThe working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine (DGN), in cooperation with the working group Nuclear Cardiology of the German Cardiac Society (DGK), decided to conduct a national survey on myocardial perfusion scintigraphy (MPS). Method: A questionnaire to evaluate MPS for the year 2005 was sent. Results: 346 completed questionnaires had been returned (213 private practices, 99 hospitals and 33 university hospitals). MPS of 112 707 patients were reported with 110 747 stress and 95 878 rest studies. The majority (>75%) was performed with 99mTc-MIBI or tetrofosmin. 201Tl stress-redistribution was used in 22 637 patients (20%). The types of stress were exercise in 78%, vasodilation with adenosine or dipyridamol in 21% and dobutamine in 1%. 99.97% of all MPS were SPECT studies. Gated SPECT was performed in 36% of the stress and in 32% of the rest studies. An attenuation correction was used in 21%. 29 institutions (8%) performed gated SPECT (stress and rest) and attenuation correction. 47% of all MPS were requested by ambulatory care cardiologists, 17% by internists, 12% by primary care physicians, 21% by hospital departments and 2% by others. Conclusion: In Germany, MPS is predominantly performed with 99mTc-perfusion agents. The common type of stress is ergometry. Gated SPECT and attenuation correction do not yet represent standards of MPS practice in Germany, which indicates some potential of optimization.

F-18-FDG Positron Imaging in Oncological Patients: Gamma Camera Coincidence Detection versus Dedicated PET

1999 ◽  
Vol 38 (04) ◽  
pp. 108-114 ◽  
Author(s):  
H.-J. Kaiser ◽  
U. Cremerius ◽  
O. Sabri ◽  
M. Schreckenberger ◽  
P. Reinartz ◽  
...  
Keyword(s):  
Attenuation Correction ◽  
Spatial Resolution ◽  
Gamma Camera ◽  
Lesion Detection ◽  
Coincidence Detection ◽  
System Sensitivity ◽  
Oncological Patients ◽  
Phantom Studies ◽  
Pet System ◽  
Dedicated Pet

Summary Aim of the present study was to investigate the feasibility of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) imaging in oncological patients with a dual head gamma camera modified for coincidence detection (MCD). Methods: Phantom studies were done to determine lesion detection at various lesion-to-background ratios, system sensitivity and spatial resolution. Thirty-two patients with suspected or known malignant disease were first studied with a dedicated full-ring PET system (DPET) applying measured attenuation correction and subsequently with an MCD system without attenuation correction. MCD images were first interpreted without knowledge of the DPET findings. In a second reading, MCD and DPET were evaluated simultaneously. Results: The phantom studies revealed a comparable spatial resolution for DPET and MCD (5.9 × 6.3 × 4.2 mm vs. 5.9 × 6.5 × 6.0 mm). System sensitivity of MCD was less compared to DPET (91 cps/Bq/ml/cmF0V vs. 231 cps/ Bq/ml/cmFOv). At a lesion-to-background ratio of 4:1, DPET depicted a minimal phantom lesion of 1.0 cm in diameter, MCD a minimal lesion of 1.6 cm. With DPET, a total of 91 lesions in 27 patients were classified as malignant. MCD without knowledge of DPET results revealed increased FDG uptake in all patients with positive DPET findings. MCD detected 72 out of 91 DPET lesions (79.1 %). With knowledge of the DPET findings, 11 additional lesions were detected (+12%). MCD missed lesions in six patients with relevance for staging in two patients. All lesions with a diameter above 18 mm were detected. Conclusion: MCD FDG imaging yielded results comparable to dedicated PET in most patients. However, a considerable number of small lesions clearly detectable with DPET were not detected by MCD alone. Therefore, MCD cannot yet replace dedicated PET in all oncological FDG studies. Further technical refinement of this new method is needed to improve image quality (e.g. attenuation correction).

scholarly journals Imaging coronary plaques using 3D motion-compensated [18F]NaF PET/MR

2021 ◽  
Author(s):  
Johannes Mayer ◽  
Thomas-Heinrich Wurster ◽  
Tobias Schaeffter ◽  
Ulf Landmesser ◽  
Andreas Morguet ◽  
...  
Keyword(s):  
Attenuation Correction ◽  
Free Breathing ◽  
Cardiac Motion ◽  
Water Fraction ◽  
3 Dimensional ◽  
Background Ratio ◽  
Motion Models ◽  
Physiological Motion ◽  
Atherosclerosis Imaging ◽  
Novel Applications

Abstract Background Cardiac PET has recently found novel applications in coronary atherosclerosis imaging using [18F]NaF as a radiotracer, highlighting vulnerable plaques. However, the resulting uptakes are relatively small, and cardiac motion and respiration-induced movement of the heart can impair the reconstructed images due to motion blurring and attenuation correction mismatches. This study aimed to apply an MR-based motion compensation framework to [18F]NaF data yielding high-resolution motion-compensated PET and MR images. Methods Free-breathing 3-dimensional Dixon MR data were acquired, retrospectively binned into multiple respiratory and cardiac motion states, and split into fat and water fraction using a model-based reconstruction framework. From the dynamic MR reconstructions, both a non-rigid cardiorespiratory motion model and a motion-resolved attenuation map were generated and applied to the PET data to improve image quality. The approach was tested in 10 patients and focal tracer hotspots were evaluated concerning their target-to-background ratio, contrast-to-background ratio, and their diameter. Results MR-based motion models were successfully applied to compensate for physiological motion in both PET and MR. Target-to-background ratios of identified plaques improved by 7 ± 7%, contrast-to-background ratios by 26 ± 38%, and the plaque diameter decreased by −22 ± 18%. MR-based dynamic attenuation correction strongly reduced attenuation correction artefacts and was not affected by stent-related signal voids in the underlying MR reconstructions. Conclusions The MR-based motion correction framework presented here can improve the target-to-background, contrast-to-background, and width of focal tracer hotspots in the coronary system. The dynamic attenuation correction could effectively mitigate the risk of attenuation correction artefacts in the coronaries at the lung-soft tissue boundary. In combination, this could enable a more reproducible and reliable plaque localisation.

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