Motion artifacts occurring at the lung/diaphragm interface using 4D CT attenuation correction of 4D PET scans

Killoran, Joseph H.; Gerbaudo, Victor H.; Mamede, Marcelo; Ionascu, Dan; Park, Sang-June; Berbeco, R.

doi:10.1120/jacmp.v12i4.3502

Cited by 21 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Comparison studies have shown that 4-dimensional PET imaging revealed differences of up to 50% compared with 3-dimensional PET imaging in measurements of maximum SUV (SUV max ) and MTV 16, 17. For current imaging equipment, different techniques have been implemented to reconstruct 4-dimensional PET images with one major development: different attenuation correction (AC) images are used for reconstruction of each phase of the 4-dimensional PET image 17, 18, 19, 20. Free-breathing helical computed tomography (FB CT) is a fast and simple method to acquire an AC image; however, it lacks breathing phase correspondence to the PET image.…”

Section: Introductionmentioning

confidence: 99%

Impact of moving target on measurement accuracy in 3D and 4D PET imaging—a phantom study

Cui

Bowsher

Cai

et al. 2017

Advances in Radiation Oncology

View full text Add to dashboard Cite

PurposeThe purpose of this study was to evaluate the impact of tumor motion on maximum standardized uptake value (SUVmax) and metabolic tumor volume (MTV) measurements in both 3-dimensional and respiratory-correlated, 4-dimensional positron emission tomography (PET) imaging. We also evaluated the effect of implementing different attenuation correction methods in 4-dimensional PET image reconstruction on SUVmax and MTV.Methods and materialsAn anthropomorphic thorax phantom with a spherical ball as a surrogate for a tumor was used. Different types of motion were imposed on the ball to mimic a patient's breathing motion. Three-dimensional PET imaging of the phantom without tumor motion was performed and used as the reference. The ball was then set in motion with different breathing motion traces and imaged with both 3- and 4-dimensional PET methods. The clinical 4-dimensional PET imaging protocol was modified so that 3 different types of attenuation correction images were used for reconstructions: the same free-breathing computed tomography (CT) for all PET phases, the same average intensity projection CT for all PET phases, and 4-dimensional CT for phase-matched attenuation correction. Tumor SUVmax and MTV values that were measured from the moving phantom were compared with the reference values.ResultsSUVmax that was measured in 3-dimensional PET imaging was different from the reference value by 20.4% on average for the motions that were investigated; this difference decreased to 2.6% with 4-dimensional PET imaging. The measurement of MTV in 4-dimensional PET also showed a similar magnitude of reduction of deviation compared with 3-dimensional PET. Four-dimensional PET with use of phase-matched 4-dimensional CT for attenuation correction showed less variation in SUVmax and MTV among phases compared with 4-dimensional PET with free-breathing CT or average intensity projection CT for attenuation correction.ConclusionsFour-dimensional PET imaging reduces the impact of motion on measured SUVmax and MTV when compared with 3-dimensional PET imaging. Clinical 4-dimensional PET imaging protocols should consider phase-matched 4-dimensional CT imaging for attenuation correction to achieve more accurate measurements.

show abstract

Section: Introductionmentioning

confidence: 99%

Impact of moving target on measurement accuracy in 3D and 4D PET imaging—a phantom study

Cui

Bowsher

Cai

et al. 2017

Advances in Radiation Oncology

View full text Add to dashboard Cite

show abstract

“…For most patients, the resulting images include approximately half of the PET coincidence events (minimal noise increase) and 20% of the relative motion events (minimal motion blurring). 20 All static and gated images were attenuation-corrected with helical CT or phase-averaged cine CT, 21 reconstructed with ordered subset expectation-maximization over 2 iterations and 28 subsets, 22 filtered with a 6-mm-wide Gaussian postreconstruction filter, and sampled onto a 70-cm transverse field-of-view grid of 3.65 mm × 3.65 mm × 3.27 mm voxels. Sample images are shown in Fig.…”

Section: Pet Image Acquisition and Reconstructionmentioning

confidence: 99%

Assessment of patient selection criteria for quantitative imaging with respiratory-gated positron emission tomography

et al. 2014

View full text Add to dashboard Cite

Abstract. The objective of this investigation was to propose techniques for determining which patients are likely to benefit from quantitative respiratory-gated imaging by correlating respiratory patterns to changes in positron emission tomography (PET) metrics. Twenty-six lung and liver cancer patients underwent PET/computed tomography exams with recorded chest/abdominal displacements. Static and adaptive amplitude-gated [ 18 F]fluoro-D-glucose (FDG) PET images were generated from list-mode acquisitions. Patients were grouped by respiratory pattern, lesion location, or degree of lesion attachment to anatomical structures. Respiratory pattern metrics were calculated during time intervals corresponding to PET field of views over lesions of interest. FDG PET images were quantified by lesion maximum standardized uptake value (SUV max ). Relative changes in SUV max between static and gated PET images were tested for association to respiratory pattern metrics. Lower lung lesions and liver lesions had significantly higher changes in SUV max than upper lung lesions (14 versus 3%, p < 0.0001). Correlation was highest (0.42 AE 0.10, r 2 ¼ 0.59, p < 0.003) between changes in SUV max and nonstandard respiratory pattern metrics. Lesion location had a significant impact on changes in PET quantification due to respiratory gating. Respiratory pattern metrics were correlated to changes in SUV max , though sample size limited statistical power. Validation in larger cohorts may enable selection of patients prior to acquisition who would benefit from respiratory-gated PET imaging.

show abstract

“…26,27 Killoran et al investigated artifacts at the lung-diaphragm interface with helical CTAC, phase-averaged 4DCT, and phase-matched 4DCT attenuation correction under sinusoidal motion. 28 They noted minor improvements in quantification with phase-matched F. 1.…”

Section: Introductionmentioning

confidence: 99%

Impact of CT attenuation correction method on quantitative respiratory‐correlated (4D) PET/CT imaging

et al. 2015

View full text Add to dashboard Cite

Purpose: Respiratory-correlated positron emission tomography (PET/CT) 4D PET/CT is used to mitigate errors from respiratory motion; however, the optimal CT attenuation correction (CTAC) method for 4D PET/CT is unknown. The authors performed a phantom study to evaluate the quantitative performance of CTAC methods for 4D PET/CT in the ground truth setting. Methods: A programmable respiratory motion phantom with a custom movable insert designed to emulate a lung lesion and lung tissue was used for this study. The insert was driven by one of five waveforms: two sinusoidal waveforms or three patient-specific respiratory waveforms. 3DPET and 4DPET images of the phantom under motion were acquired and reconstructed with six CTAC methods: helical breath-hold (3DHEL), helical free-breathing (3DMOT), 4D phase-averaged (4DAVG), 4D maximum intensity projection (4DMIP), 4D phase-matched (4DMATCH), and 4D end-exhale (4DEXH) CTAC. Recovery of SUV max , SUV mean , SUV peak , and segmented tumor volume was evaluated as RC max , RC mean , RC peak , and RC vol , representing percent difference relative to the static ground truth case. Paired Wilcoxon tests and Kruskal-Wallis ANOVA were used to test for significant differences. Results: For 4DPET imaging, the maximum intensity projection CTAC produced significantly more accurate recovery coefficients than all other CTAC methods (p < 0.0001 over all metrics). Over all motion waveforms, ratios of 4DMIP CTAC recovery were 0.2 ± 5.4, −1.8 ± 6.5, −3.2 ± 5.0, and 3.0 ± 5.9 for RC max , RC peak , RC mean , and RC vol . In comparison, recovery coefficients for phase-matched CTAC were −8.4 ± 5.3, −10.5 ± 6.2, −7.6 ± 5.0, and −13.0 ± 7.7 for RC max , RC peak , RC mean , and RC vol . When testing differences between phases over all CTAC methods and waveforms, end-exhale phases were significantly more accurate (p = 0.005). However, these differences were driven by the patient-specific respiratory waveforms; when testing patient and sinusoidal waveforms separately, patient waveforms were significantly different between phases (p < 0.0001) while the sinusoidal waveforms were not significantly different (p = 0.98). When considering only the subset of 4DMATCH images that corresponded to the end-exhale image phase, 4DEXH, mean and interquartile range were similar to 4DMATCH but variability was considerably reduced. Conclusions: Comparative advantages in accuracy and precision of SUV metrics and segmented volumes were demonstrated with the use of the maximum intensity projection and end-exhale CT attenuation correction. While respiratory phase-matched CTAC should in theory provide optimal corrections, image artifacts and differences in implementation of 4DCT and 4DPET sorting can degrade the benefit of this approach. These results may be useful to guide the implementation, analysis, and development of respiratory-correlated thoracic PET/CT in the radiation oncology and diagnostic settings.

show abstract

Motion artifacts occurring at the lung/diaphragm interface using 4D CT attenuation correction of 4D PET scans

Cited by 21 publications

References 25 publications

Impact of moving target on measurement accuracy in 3D and 4D PET imaging—a phantom study

Impact of moving target on measurement accuracy in 3D and 4D PET imaging—a phantom study

Assessment of patient selection criteria for quantitative imaging with respiratory-gated positron emission tomography

Impact of CT attenuation correction method on quantitative respiratory‐correlated (4D) PET/CT imaging

Contact Info

Product

Resources

About