An Attenuation Correction Method for Respiratory-Gated PET/CT Image

Yamazaki, Takahiro; Ue, Hidenori; Haneishi, Hideaki; Hirayama, Akira; Sato, Takashi; Nakamura, Shigeru

doi:10.1109/nssmic.2006.353711

Cited by 3 publications

(3 citation statements)

References 6 publications

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“…These methods include respiratory-gated PET / CT (Nehmeh et al 2004a, 2004b, Pan et al 2004, 2007, Rietzel et al 2005, Wolthaus et al 2005, Abdelnour et al 2007, Dawood et al 2007, Guckenberger et al 2007, Lu et al 2006, Wink et al 2006), deep-inspiration-breathhold (DIBH) PET / CT (Kawano et al 2008, Meirelles et al 2007, Nehmeh et al 2007), postprocessing methods (Dawood et al 2006, Yamazaki et al 2006) and motion-corrected PET reconstruction (Lamare et al 2007, Li et al 2006, Qiao et al 2006, 2007). …”

Section: Introductionmentioning

confidence: 99%

The impact of respiratory motion on tumor quantification and delineation in static PET/CT imaging

Liu¹,

et al. 2009

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Our aim is to investigate the impact of respiratory motion on tumor quantification and delineation in static PET/CT imaging using a population of patient respiratory traces. A total of 1295 respiratory traces acquired during whole body PET/CT imaging were classified into three types according to the qualitative shape of their signal histograms. Each trace was scaled to three diaphragm motion amplitudes (6 mm, 11 mm and 16 mm) to drive a whole body PET/CT computer simulation that was validated with a physical phantom experiment. Three lung lesions and one liver lesion were simulated with diameters of 1 cm and 2 cm. PET data were reconstructed using the OS-EM algorithm with attenuation correction using CT images at the end-expiration phase and respiratory-averaged CT. The errors of the lesion maximum standardized uptake values (SUV max ) and lesion volumes between motion-free and motion-blurred PET/CT images were measured and analyzed. For respiration with 11 mm diaphragm motion and larger quiescent period fraction, respiratory motion can cause a mean lesion SUV max underestimation of 28% and a mean lesion volume overestimation of 130% in PET/CT images with 1 cm lesions. The errors of lesion SUV max and volume are larger for patient traces with larger motion amplitudes. Smaller lesions are more sensitive to respiratory motion than larger lesions for the same motion amplitude. Patient respiratory traces with relatively larger quiescent period fraction yield results less subject to respiratory motion than traces with long-term amplitude variability. Mismatched attenuation correction due to respiratory motion can cause SUV max overestimation for lesions in the lower lung region close to the liver dome. Using respiratoryaveraged CT for attenuation correction yields smaller mismatch errors than those using endexpiration CT. Respiratory motion can have a significant impact on static oncological PET/CT imaging where SUV and/or volume measurements are important. The impact is highly dependent upon motion amplitude, lesion location and size, attenuation map and respiratory pattern. To overcome the motion effect, motion compensation techniques may be necessary in clinical practice to improve the tumor quantification for determining the response to therapy or for radiation treatment planning.

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Section: Introductionmentioning

confidence: 99%

The impact of respiratory motion on tumor quantification and delineation in static PET/CT imaging

Liu¹,

et al. 2009

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“…14 Proposed motion compensation methods using all the detected coincident events typically start with respiratory-gated PET and/or CT data and incorporate estimated image-based motion information either into the image reconstruction [17][18][19][20][21][22] or postprocessing. [23][24][25] The image-based motion information used in these methods can be derived either from respiratory-gated PET or CT images. Motion estimation from gated PET is subject to the high levels of image noise, leading to potential error in the estimated motion that can propagate into the motion corrected images.…”

Section: Introductionmentioning

confidence: 99%

Quiescent period respiratory gating for PET/CT

et al. 2010

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Purpose: To minimize respiratory motion artifacts, this work proposes quiescent period gating ͑QPG͒ methods that extract PET data from the end-expiration quiescent period and form a single PET frame with reduced motion and improved signal-to-noise properties. Methods: Two QPG methods are proposed and evaluated. Histogram-based quiescent period gating ͑H-QPG͒ extracts a fraction of PET data determined by a window of the respiratory displacement signal histogram. Cycle-based quiescent period gating ͑C-QPG͒ extracts data with a respiratory displacement signal below a specified threshold of the maximum amplitude of each individual respiratory cycle. Performances of both QPG methods were compared to ungated and five-bin phase-gated images across 21 FDG-PET/CT patient data sets containing 31 thorax and abdomen lesions as well as with computer simulations driven by 1295 different patient respiratory traces. Image quality was evaluated in terms of the lesion SUV max and the fraction of counts included in each gate as a surrogate for image noise. Results: For all the gating methods, image noise artifactually increases SUV max when the fraction of counts included in each gate is less than 50%. While simulation data show that H-QPG is superior to C-QPG, the H-QPG and C-QPG methods lead to similar quantification-noise tradeoffs in patient data. Compared to ungated images, both QPG methods yield significantly higher lesion SUV max . Compared to five-bin phase gating, the QPG methods yield significantly larger fraction of counts with similar SUV max improvement. Both QPG methods result in increased lesion SUV max for patients whose lesions have longer quiescent periods. Conclusions: Compared to ungated and phase-gated images, the QPG methods lead to images with less motion blurring and an improved compromise between SUV max and fraction of counts. The QPG methods for respiratory motion compensation could effectively improve tumor quantification with minimal noise increase.

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“…These methods typically start with respiratory-gated PET or CT data and incorporate estimated image-based motion vectors either into the image reconstruction [19][20][21][22][23][24] or postprocessing. [25][26][27] The image-based motion vector used in these methods can be derived either from respiratory-gated PET or CT images. If estimated from gated PET images, the motion vectors are subject to the high levels of image noise, and the estimation errors can propagate into the motion-corrected images.…”

Section: Introductionmentioning

confidence: 99%

Respiratory motion correction for quantitative PET/CT using all detected events with internal-external motion correlation

2011

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Purpose: We present a method to correct respiratory motion blurring in PET/CT imaging using internal-external (INTEX) motion correlation. The internal motion of a known tumor is derived from respiratory-gated PET images; this internal motion is then correlated with external respiratory signals to determine the complete information of tumor motion during the scan. Methods: For each PET/CT data, PET listmode data were phase-gated into five bins and reconstructed. The centroid of a targeted tumor in each bin was determined and correlated with the corresponding mean displacement of externally monitored respiratory motion signal. Based on this correlation, the external motion signal was converted into internal tumor motion information in the superior-inferior direction. Then, the PET listmode data were binned sequentially to multiple 1-s sinograms. According to the converted internal tumor motion signal, each 1-s sinogram was registered to a reference frame, which best matched the helical CT attenuation map based on consistency conditions. The registered sinograms were summed and reconstructed to form an image, corrected for the motion of the specific tumor. In this study, the proposed INTEX method was evaluated with phantom and patient studies in terms of tracer concentration and volume. Results: The INTEX method effectively recovered the tracer concentration to the level of the stationary scan data in the phantom experiment. In the patient study, the INTEX method yielded a (17 6 22)% tumor volume decrease and a (10 6 10)% tumor SUVmax increase compared to nongated images. Conclusions: The proposed INTEX method reduces respiratory motion degradation of PET tumor quantification and delineation in an effective manner. This can be used to improve the assessment of response to therapy for a known tumor by minimizing residual motion and matching the attenuation correction, without increasing image noise.

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An Attenuation Correction Method for Respiratory-Gated PET/CT Image

Cited by 3 publications

References 6 publications

The impact of respiratory motion on tumor quantification and delineation in static PET/CT imaging

The impact of respiratory motion on tumor quantification and delineation in static PET/CT imaging

Quiescent period respiratory gating for PET/CT

Respiratory motion correction for quantitative PET/CT using all detected events with internal-external motion correlation

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