Validation of a Multimodality Flow Phantom and Its Application for Assessment of Dynamic SPECT and PET Technologies

Gabrani-Juma, Hanif; Clarkin, Owen; Pourmoghaddas, Amir; Driscoll, Brandon; Wells, R. Glenn; deKemp, Robert A.; Klein, Ran

doi:10.1109/tmi.2016.2599779

Cited by 19 publications

(32 citation statements)

References 27 publications

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“…To this end, Driscoll and colleagues proposed a phantom simulating two‐compartmental exchange for dynamic contrast‐enhanced (DCE) imaging 20 . The phantom was shown to generate reproducible signal intensity‐time (SI) curves during first‐pass perfusion experiments with computed tomography (CT), PET, and single‐photon emission CT and is currently the only commercially available phantom of its kind 20,21 . Nevertheless, the phantom does not include a full heart model, generates a homogeneous flow distribution within the myocardium, and has not yet been used with MRI.…”

Section: Introductionmentioning

confidence: 99%

“…However, the phantom lacks diversity in capillary size and its low manufacturing reproducibility potentially hampers its commercialization. Both aforementioned phantoms have proven useful in the assessment of perfusion methodologies, but their design limits their use to the measurement of spatially homogeneous perfusion rate and, therefore, allow only global perfusion validation 5,21,23‐25 . Others proposed the use of a real perfused heart in a hardware phantom for physiological perfusion experiments, though the sacrifice of large animals, its high costs, and complicated pre‐scan preparations preclude routine use in the clinic 15,26 …”

Section: Introductionmentioning

confidence: 99%

“…Both aforementioned phantoms have proven useful in the assessment of perfusion methodologies, but their design limits their use to the measurement of spatially homogeneous perfusion rate and, therefore, allow only global perfusion validation. 5,21,[23][24][25] Others proposed the use of a real perfused heart in a hardware phantom for physiological perfusion experiments, though the sacrifice of large animals, its high costs, and complicated pre-scan preparations preclude routine use in the clinic. 15,26 Perfusion phantoms offer distinct advantages in terms of reproducibility in generating DCE-MRI data and providing reliable reference values and, as such, have the possibility to be established as true gold standards across institutions.…”

Section: Introductionmentioning

confidence: 99%

“… 20 The phantom was shown to generate reproducible signal intensity-time (SI) curves during first-pass perfusion experiments with computed tomography (CT), PET, and single-photon emission CT and is currently the only commercially available phantom of its kind. 20 , 21 Nevertheless, the phantom does not include a full heart model, generates a homogeneous flow distribution within the myocardium, and has not yet been used with MRI. Chiribiri et al developed a phantom with a four-chamber heart and a more complex myocardium.…”

Section: Introductionmentioning

confidence: 99%

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Pixel‐wise assessment of cardiovascular magnetic resonance first‐pass perfusion using a cardiac phantom mimicking transmural myocardial perfusion gradients

Milidonis

Nazir

Schneider

et al. 2020

Magnetic Resonance in Med

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Purpose Cardiovascular magnetic resonance first‐pass perfusion for the pixel‐wise detection of coronary artery disease is rapidly becoming the clinical standard, yet no widely available method exists for its assessment and validation. This study introduces a novel phantom capable of generating spatially dependent flow values to enable assessment of new perfusion imaging methods at the pixel level. Methods A synthetic multicapillary myocardial phantom mimicking transmural myocardial perfusion gradients was designed and manufactured with high‐precision 3D printing. The phantom was used in a stationary flow setup providing reference myocardial perfusion rates and was scanned on a 3T system. Repeated first‐pass perfusion MRI for physiological perfusion rates between 1 and 4 mL/g/min was performed using a clinical dual‐sequence technique. Fermi function‐constrained deconvolution was used to estimate pixel‐wise perfusion rate maps. Phase contrast (PC)‐MRI was used to obtain velocity measurements that were converted to perfusion rates for validation of reference values and cross‐method comparison. The accuracy of pixel‐wise maps was assessed against simulated reference maps. Results PC‐MRI indicated excellent reproducibility in perfusion rate (coefficient of variation [CoV] 2.4‐3.5%) and correlation with reference values (R2 = 0.985) across the full physiological range. Similar results were found for first‐pass perfusion MRI (CoV 3.7‐6.2%, R2 = 0.987). Pixel‐wise maps indicated a transmural perfusion difference of 28.8‐33.7% for PC‐MRI and 23.8‐37.7% for first‐pass perfusion, matching the reference values (30.2‐31.4%). Conclusion The unique transmural perfusion pattern in the phantom allows effective pixel‐wise assessment of first‐pass perfusion acquisition protocols and quantification algorithms before their introduction into routine clinical use.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Pixel‐wise assessment of cardiovascular magnetic resonance first‐pass perfusion using a cardiac phantom mimicking transmural myocardial perfusion gradients

Milidonis

Nazir

Schneider

et al. 2020

Magnetic Resonance in Med

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“…Using pumps to control the flow of radioactivity into and out of compartments in the phantom, it is possible to simulate the kinetic behavior found in MBF studies. 8,9 To date, these phantoms have provided time-varying activity within stationary structures and have been criticized for their lack of anatomical realism and their neglect of physiologic cardiac and respiratory motion. Phantoms also have previously been developed to explore the accuracy of ECG-gated SPECT imaging at measuring myocardial volumes and ejection fractions.…”

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confidence: 99%

Dynamic phantoms: Making the right tool for the job

Wells

Klein

2021

Journal of Nuclear Cardiology

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Myocardial blood flow (MBF) measurement has been shown to add incremental value in the diagnosis and prognosis of patients with coronary artery disease. New cardiac cameras make dynamic imaging possible with SPECT and there has been substantial interest in SPECT MBF. As with any new clinical test, a need exists to validate its results, characterize its limitations, and benchmark its performance with evolving methodology. As a test moves into clinical implementation there is a further need to ensure the quality, both of the camera performance in the acquisition of the data and of the processing of that data. Meeting these needs can be readily achieved if there exists a well-controlled reference truth that realistically emulates the inputs to the test.For conventional gamma cameras, there already exist standards for assuring camera performance with respect to static imaging, 1 but many of these tests are not applicable to the new cardiac SPECT camera designs. In addition, as we move into dynamic imaging, there are even less standards available to test and assure accurate performance. From work with PET, we know that camera technical factors such as deadtime corrections 2 and type of reconstruction 3 can influence the values measured for MBF. Therefore, we need to develop new standards for characterizing camera performance, to understand how camera performance influences MBF measurement and to ensure accurate camera performance over its useful life. The ideal test will efficiently test the performance of the complete system, not just select components, by simulating its input and validating the final result.When asking questions about the capability of the design of a system, computer simulations can be extremely valuable. Complex anthropomorphic computer phantoms (such as the XCAT phantom) 4 are available to simulate time-varying activity distributions in the patient, complete with respiratory motion, cardiac contraction and myocardial defects. Coupling these with an accurate model of the camera itself, Monte Carlo simulation (e.g. with GATE 5 or Simind) 6 can provide very realistic datasets for which the truth is well known. Computer simulations also have the advantage that with them we can alter reality-we can turn-off patient breathing, remove scatter or attenuation, increase the tracer extraction fraction-and examine each aspect of the problem and the effect it might have on the final measurement of MBF. However, despite the benefits of computer modeling and the wealth of information it might provide on the ideal performance of a system, it can only simulate what the operator designs into it and there is often an element of doubt that the simulation is accurately modeling all aspects of the problem, especially if complete knowledge of the system (i.e. camera hardware and software) is not known. In addition, and perhaps more importantly, computer simulations can tell us how well the camera design works but cannot tell us how well the camera in our department works.To assess your camera's performance, you need to...

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Development of a dedicated 3D printed myocardial perfusion phantom: proof-of-concept in dynamic SPECT

Kamphuis

Vries

Kuipers

et al. 2022

Med Biol Eng Comput

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We aim to facilitate phantom-based (ground truth) evaluation of dynamic, quantitative myocardial perfusion imaging (MPI) applications. Current MPI phantoms are static representations or lack clinical hard- and software evaluation capabilities. This proof-of-concept study demonstrates the design, realisation and testing of a dedicated cardiac flow phantom. The 3D printed phantom mimics flow through a left ventricular cavity (LVC) and three myocardial segments. In the accompanying fluid circuit, tap water is pumped through the LVC and thereafter partially directed to the segments using adjustable resistances. Regulation hereof mimics perfusion deficit, whereby flow sensors serve as reference standard. Seven phantom measurements were performed while varying injected activity of 99mTc-tetrofosmin (330–550 MBq), cardiac output (1.5–3.0 L/min) and myocardial segmental flows (50–150 mL/min). Image data from dynamic single photon emission computed tomography was analysed with clinical software. Derived time activity curves were reproducible, showing logical trends regarding selected input variables. A promising correlation was found between software computed myocardial flows and its reference ($$\rho$$ ρ = − 0.98; p = 0.003). This proof-of-concept paper demonstrates we have successfully measured first-pass LV flow and myocardial perfusion in SPECT-MPI using a novel, dedicated, myocardial perfusion phantom. Graphical abstract This proof-of-concept study focuses on the development of a novel, dedicated myocardial perfusion phantom, ultimately aiming to contribute to the evaluation of quantitative myocardial perfusion imaging applications.

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Validation of a Multimodality Flow Phantom and Its Application for Assessment of Dynamic SPECT and PET Technologies

Cited by 19 publications

References 27 publications

Pixel‐wise assessment of cardiovascular magnetic resonance first‐pass perfusion using a cardiac phantom mimicking transmural myocardial perfusion gradients

Pixel‐wise assessment of cardiovascular magnetic resonance first‐pass perfusion using a cardiac phantom mimicking transmural myocardial perfusion gradients

Dynamic phantoms: Making the right tool for the job

Development of a dedicated 3D printed myocardial perfusion phantom: proof-of-concept in dynamic SPECT

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