Improvement in PET/CT image quality in overweight patients with PSF and TOF

Taniguchi, Takafumi; Akamatsu, Go; Kasahara, Yukiko; Mitsumoto, Katsuhiko; Baba, Shingo; Tsutsui, Yuji; Himuro, Kazuhiko; Mikasa, Shohei; Kidera, Daisuke; Sasaki, Masayuki

doi:10.1007/s12149-014-0912-z

Cited by 44 publications

(38 citation statements)

References 19 publications

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“…This study did not take the subject size into consideration. However, the PET image quality of overweight subjects (body mass index $ 25) is degraded because of an increase in statistical noise (29)(30)(31). To obtain sufficient image quality, adjusting the injection activity or scanning time in each patient based on body weight or body mass index (29,32,33) might be required for overweight subjects (34,35).…”

Section: Discussionmentioning

confidence: 99%

Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUV_max and SUV_peak: A Phantom Study

Akamatsu

Ikari

Nishida

et al. 2015

J. Nucl. Med. Technol.

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Standardized uptake values (SUVs) have been widely used in the diagnosis of malignant tumors and in clinical trials of tumor therapies as semiquantitative metrics of tumor 18 F-FDG uptake. However, SUVs for small lesions are liable to errors due to partialvolume effect and statistical noise. The purpose of this study was to evaluate the reproducibility and accuracy of maximum and peak SUV (SUV max and SUV peak , respectively) of small lesions in phantom experiments. Methods: We used a body phantom with 6 spheres in a quarter warm background. The PET data were acquired for 1,800 s in list-mode, from which data were extracted to generate 15 PET images for each of the 60-, 90-, 120-, 150-, and 180-s scanning times. The SUV max and SUV peak of the hot spheres in the 1,800-s scan were used as a reference (SUV ref,max and SUV ref,peak ). Coefficients of variation for both SUV max and SUV peak in hot spheres (CV max and CV peak ) were calculated to evaluate the variability of the SUVs. On the other hand, percentage differences between SUV max and SUV ref,max and between SUV peak and SUV ref,peak were calculated for evaluation of the accuracy of SUV. We additionally examined the coefficients of variation of background activity and the percentage background variability as parameters for the physical assessment of image quality. Results: Visibility of a 10-mm-diameter hot sphere was considerably different among scan frames. The CV max and CV peak increased as the sphere size became smaller and as the acquisition time became shorter. SUV max was generally overestimated as the scan time shortened and the sphere size increased. The SUV max and SUV peak of a 37-mm-diameter sphere for 60-s scans had average positive biases of 28.3% and 4.4%, compared with the reference. Conclusion: SUV max was variable and overestimated as the scan time decreased and the sphere size increased. In contrast, SUV peak was a more robust and accurate metric than SUV max . The measurements of SUV peak (or SUV peak normalized to lean body mass) in addition to SUV max are desirable for reproducible and accurate quantification in clinical situations.

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Section: Discussionmentioning

confidence: 99%

Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUV_max and SUV_peak: A Phantom Study

Akamatsu

Ikari

Nishida

et al. 2015

J. Nucl. Med. Technol.

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“…The highest SNR was attained in images reconstructed with OSEM + PSF + TOF. This method of reconstruction was thus found to improve the image quality for overweight patients [9]. Although image quality is improved, clinical usefulness of images depends on lesion detectability, and the research does not indicate that improved image quality due to PSF and TOF translates into clinical usefulness.…”

Section: Potential Of Tof and Psf In Patient Dose Administration Basementioning

confidence: 92%

“…3D PET reconstruction with PSF modeling shows on by 45% and contrast On the same hand, comparison of PSF with PSF images showed a mean bias up to 12% for 8% for SUVmean, and 7,5% for SUVpeak [8]. In addition, it has been shown that, combined with the OSEM algorithms, image quality, especially for overweight patients, could be TOF [5,9]. Armstrong et.al.…”

Section: In Pet Medicalmentioning

confidence: 99%

“…al. evaluated image quality in four distinct reconstructions: OSEM alone, OSEM + PSF, OSEM + TOF, and OSEM + PSF + TOF [9]. The combination OSEM + PSF + TOF decreased the coefficient of variance of the liver for overweight patients to that for normal weight patients while increasing the SNR similarly between two patient groups.…”

Section: Potential Of Tof and Psf In Patient Dose Administration Basementioning

confidence: 99%

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Need for Revising Patient Dose Protocols in Pet Medical Imaging Based on Novel Technology Improvements

Antić¹,

Haglund²

2016

RAD Conference Proceedings

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Abstract. Clinical studies have shown that it is possible to improve image contrast up to 30% when time of flight (TOF) technology is used compared to non-TOF technology [1]. On the other hand, it has been shown that, combined with the point spread function (PSF) in image quality for overweight patients could study and a change of the dose model based on patient weight. This chan EANM procedure guidelines, either replacing them or combining them with a system based on a body-mass-index (BMI) concept, and thus result in significant dose reductions with stronger patient-based dose optimisation. This will also reduce exposure of the nuclear medicine staff. Bearing in mind that the compromise in clinical practice is either to reduce the time of the scan or to reduce the patient dose, and that this depends mostly on whether a facility has a medical cyclotron or not, this work focuses on the overview of possibilities for potential based on appropriate clinical studies.

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“…And, they gave the assumption that the degradation function of CT system has Gaussian distribution. Multiple sets of bone interfaces and the iterative strategy [4][5][6] were utilized to estimate the point spread function. Blind equalization algorithm was applied to the two-dimensional CT blind image restoration [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

Zhang

Sun

Zhang

et al. 2017

J Image Video Proc.

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To solve the problem of CT image degradation, a double regularization CT image blind restoration reconstruction method was proposed. The objective function including both a clear image and point spread function was established. To avoid the over-smoothing phenomenon and protect the detail, the objective function includes two constraint regularization terms. They are total variation (TV) and wavelet sparsity respectively. The objective function was solved by the alternating direction multiplier method (ADMM), and the optimal solution was obtained. Firstly, the CT image blind restoration reconstruction was decomposed into two sub-problems: reconstructed image estimation and point spread function estimation. Furthermore, each sub-problem can be solved by the proximal alternating direction method of multipliers. Finally, the CT image blind restoration reconstruction was realized. The experimental results show that the proposed algorithm takes into account the degradation effect of projection data, and the proposed algorithm is superior to other existing algorithms in the subjective visual effect. At the same time, in the aspect of objective evaluation, the proposed algorithm improves the objective image quality metrics such as peak signal-to-noise ratio (PSNR), structural similarity index metric (SSIM), and universal image quality index (UIQI).

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Improvement in PET/CT image quality in overweight patients with PSF and TOF

Cited by 44 publications

References 19 publications

Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUV_max and SUV_peak: A Phantom Study

Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUV_max and SUV_peak: A Phantom Study

Need for Revising Patient Dose Protocols in Pet Medical Imaging Based on Novel Technology Improvements

Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

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Improvement in PET/CT image quality in overweight patients with PSF and TOF

Cited by 44 publications

References 19 publications

Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUVmax and SUVpeak: A Phantom Study

Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUVmax and SUVpeak: A Phantom Study

Need for Revising Patient Dose Protocols in Pet Medical Imaging Based on Novel Technology Improvements

Double regularization medical CT image blind restoration reconstruction based on proximal alternating direction method of multipliers

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Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUV_max and SUV_peak: A Phantom Study

Influence of Statistical Fluctuation on Reproducibility and Accuracy of SUV_max and SUV_peak: A Phantom Study