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Dietze MMA, de Jong HWAM. Progress in large field-of-view interventional planar scintigraphy and SPECT imaging. Expert Rev Med Devices 2022; 19:393-403. [PMID: 35695477 DOI: 10.1080/17434440.2022.2088355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Handheld gamma cameras and gamma probes have been successfully implemented for enabling nuclear image or radio-guidance in minimally-invasive procedures. There is an opportunity for large field-of-view interventional planar scintigraphy and SPECT imaging to complement these small field-of-view devices for two reasons. First, a large field-of-view camera enables imaging of relatively larger organs and activity accumulations that are not close to the patient's skin. And second, more precise corrections can be implemented in the SPECT reconstruction algorithm, improving its quality. AREAS COVERED This review article discusses the progress that has been made in the field of large field-of-view interventional planar scintigraphy and SPECT imaging. First, an overview of planar scintigraphy and SPECT is provided. Second, an exploration is given of the potential applications where large field-of-view interventional planar scintigraphy and SPECT imaging may be employed. And third, the requirements for scanner hardware are discussed and an overview of the possible system configurations is provided. EXPERT OPINION We believe that there is an opportunity for large field-of-view interventional planar scintigraphy and SPECT imaging to assist clinical workflows. A major effort is now required to evaluate the prototype systems in clinical studies so that valuable practical experience can be obtained.
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Affiliation(s)
- Martijn M A Dietze
- Radiology and Nuclear Medicine, Utrecht University and University Medical Center, Utrecht, Netherlands
| | - Hugo W A M de Jong
- Radiology and Nuclear Medicine, Utrecht University and University Medical Center, Utrecht, Netherlands
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Dietze MMA, Kunnen B, Brontsema F, Ramaekers P, Beijst C, Afifah M, Braat AJAT, Lam MGEH, de Jong HWAM. A compact and mobile hybrid C-arm scanner for simultaneous nuclear and fluoroscopic image guidance. Eur Radiol 2021; 32:517-523. [PMID: 34132877 PMCID: PMC8660732 DOI: 10.1007/s00330-021-08023-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/22/2021] [Accepted: 04/27/2021] [Indexed: 11/24/2022]
Abstract
Purpose This study evaluates the performance of a mobile and compact hybrid C-arm scanner (referred to as IXSI) that is capable of simultaneous acquisition of 2D fluoroscopic and nuclear projections and 3D image reconstruction in the intervention room. Results The impact of slightly misaligning the IXSI modalities (in an off-focus geometry) was investigated for the reduction of the fluoroscopic and nuclear interference. The 2D and 3D nuclear image quality of IXSI was compared with a clinical SPECT/CT scanner by determining the spatial resolution and sensitivity of point sources and by performing a quantitative analysis of the reconstructed NEMA image quality phantom. The 2D and 3D fluoroscopic image of IXSI was compared with a clinical CBCT scanner by visualizing the Fluorad A+D image quality phantom and by visualizing a reconstructed liver nodule phantom. Finally, the feasibility of dynamic simultaneous nuclear and fluoroscopic imaging was demonstrated by injecting an anthropomorphic phantom with a mixture of iodinated contrast and 99mTc. Conclusion Due to the divergent innovative hybrid design of IXSI, concessions were made to the nuclear and fluoroscopic image qualities. Nevertheless, IXSI realizes unique image guidance that may be beneficial for several types of procedures. Key Points • IXSI can perform time-resolved planar (2D) simultaneous fluoroscopic and nuclear imaging. • IXSI can perform SPECT/CBCT imaging (3D) inside the intervention room. Supplementary Information The online version contains supplementary material available at 10.1007/s00330-021-08023-4.
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Affiliation(s)
- Martijn M A Dietze
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands. .,Image Sciences Institute, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
| | - Britt Kunnen
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.,Image Sciences Institute, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Frank Brontsema
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Pascal Ramaekers
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Casper Beijst
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Maryam Afifah
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Arthur J A T Braat
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Marnix G E H Lam
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
| | - Hugo W A M de Jong
- Radiology and Nuclear Medicine, University Medical Center Utrecht and Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
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Dietze MMA, Kunnen B, Lam MGEH, de Jong HWAM. Interventional respiratory motion compensation by simultaneous fluoroscopic and nuclear imaging: a phantom study. Phys Med Biol 2021; 66:065001. [PMID: 33571969 DOI: 10.1088/1361-6560/abe556] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE A compact and mobile hybrid c-arm scanner, capable of simultaneously acquiring nuclear and fluoroscopic projections and SPECT/CBCT, was developed to aid fluoroscopy-guided interventional procedures involving the administration of radionuclides (e.g. hepatic radioembolization). However, as in conventional SPECT/CT, the acquired nuclear images may be deteriorated by patient respiratory motion. We propose to perform compensation for respiratory motion by extracting the motion signal from fluoroscopic projections so that the nuclear counts can be gated into motion bins. The purpose of this study is to quantify the performance of this motion compensation technique with phantom experiments. METHODS Anthropomorphic phantom configurations that are representative of distributions obtained during the pre-treatment procedure of hepatic radioembolization were placed on a stage that translated with three different motion patterns. Fluoroscopic projections and nuclear counts were simultaneously acquired under planar and SPECT/CBCT imaging. The planar projections were visually assessed. The SPECT reconstructions were visually assessed and quantitatively assessed by calculating the activity recovery of the spherical inserts in the phantom. RESULTS The planar nuclear projections of the translating anthropomorphic phantom were blurry when no motion compensation was applied. With motion compensation, the nuclear projections became representative of the stationary phantom nuclear projection. Similar behavior was observed for the visual quality of SPECT reconstructions. The mean error of the activity recovery in the uncompensated SPECT reconstructions was 15.8% ± 0.9% for stable motion, 11.9% ± 0.9% for small variations, and 11.0% ± 0.9% for large variations. When applying motion compensation, the mean error decreased to 1.8% ± 1.6% for stable motion, 2.2% ± 1.5% for small variations, and 5.2% ± 2.5% for large variations. CONCLUSION A compact and mobile hybrid c-arm scanner, capable of simultaneously acquiring nuclear and fluoroscopic projections, can perform compensation for respiratory motion. Such motion compensation results in sharper planar nuclear projections and increases the quantitative accuracy of the SPECT reconstructions.
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Affiliation(s)
- Martijn M A Dietze
- Radiology and Nuclear Medicine, Utrecht University and University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands. Image Sciences Institute, Utrecht University and University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands
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Dietze MMA, Bastiaannet R, Kunnen B, van der Velden S, Lam MGEH, Viergever MA, de Jong HWAM. Respiratory motion compensation in interventional liver SPECT using simultaneous fluoroscopic and nuclear imaging. Med Phys 2019; 46:3496-3507. [PMID: 31183868 PMCID: PMC6851796 DOI: 10.1002/mp.13653] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 06/03/2019] [Accepted: 06/04/2019] [Indexed: 01/22/2023] Open
Abstract
PURPOSE Quantitative accuracy of the single photon emission computed tomography (SPECT) reconstruction of the pretreatment procedure of liver radioembolization is crucial for dosimetry; visual quality is important for detecting doses deposited outside the planned treatment volume. Quantitative accuracy is limited by respiratory motion. Conventional gating eliminates motion by count rejection but increases noise, which degrades the visual reconstruction quality. Motion compensation using all counts can be performed if the motion signal and motion vector field over time are known. The measurement of the motion signal of a patient currently requires a device (such as a respiratory belt) attached to the patient, which complicates the acquisition. The motion vector field is generally extracted from a previously acquired four-dimensional scan and can differ from the motion in the scan performed during the intervention. The simultaneous acquisition of fluoroscopic and nuclear projections can be used to obtain both the motion vector field and the projections of the corresponding (moving) activity distribution. This eliminates the need for devices attached to the patient and provides an accurate motion vector field for SPECT reconstruction. Our approach to motion compensation would primarily be beneficial for interventional SPECT because the time-critical setting requires fast scans and no inconvenience of an external apparatus. The purpose of this work is to evaluate the performance of the motion compensation approach for interventional liver SPECT by means of simulations. METHODS Nuclear and fluoroscopic projections of a realistic digital human phantom with respiratory motion were generated using fast Monte Carlo simulators. Fluoroscopic projections were sampled at 1-5 Hz. Nuclear data were acquired continuously in list mode. The motion signal was extracted from the fluoroscopic projections by calculating the center-of-mass, which was then used to assign each photon to a corresponding motion bin. The fluoroscopic projections were reconstructed per bin and coregistered, resulting in a motion vector field that was used in the SPECT reconstruction. The influence of breathing patterns, fluoroscopic imaging dose, sampling rate, number of bins, and scanning time was studied. In addition, the motion compensation method was compared with conventional gating to evaluate the detectability of spheres with varying uptake ratios. RESULTS The liver motion signal was accurately extracted from the fluoroscopic projections, provided the motion was stable in amplitude and the sampling rate was greater than 2 Hz. The minimum total fluoroscopic dose for the proposed method to function in a 5-min scan was 10 µGy. Although conventional gating improved the quantitative reconstruction accuracy, substantial background noise was observed in the short scans because of the limited counts available. The proposed method similarly improved the quantitative accuracy, but generated reconstructions with higher visual quality. The proposed method provided better visualization of low-contrast features than when using gating. CONCLUSION The proposed motion compensation method has the potential to improve SPECT reconstruction quality. The method eliminates the need for external devices to measure the motion signal and generates an accurate motion vector field for reconstruction. A minimal increase in the fluoroscopic dose is required to substantially improve the results, paving the way for clinical use.
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Affiliation(s)
- Martijn M. A. Dietze
- Radiology and Nuclear MedicineUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
| | - Remco Bastiaannet
- Radiology and Nuclear MedicineUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
| | - Britt Kunnen
- Radiology and Nuclear MedicineUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
| | - Sandra van der Velden
- Radiology and Nuclear MedicineUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
| | - Marnix G. E. H. Lam
- Radiology and Nuclear MedicineUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
| | - Max A. Viergever
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
| | - Hugo W. A. M. de Jong
- Radiology and Nuclear MedicineUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
- Image Sciences InstituteUtrecht University and University Medical Center UtrechtP.O. Box 855003508 GAUtrechtthe Netherlands
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Dietze MMA, Kunnen B, van der Velden S, Steenbergen JHL, Koppert WJC, Viergever MA, de Jong HWAM. Performance of a dual-layer scanner for hybrid SPECT/CBCT. Phys Med Biol 2019; 64:105020. [PMID: 30947146 DOI: 10.1088/1361-6560/ab15f6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fluoroscopic procedures involving radionuclides would benefit from interventional nuclear imaging by obtaining real-time feedback on the activity distribution. We have previously proposed a dual-layer detector that offers such procedural guidance by simultaneous fluoroscopic and nuclear planar imaging. Acquisition of single photon computed tomography (SPECT) and cone beam computed tomography (CBCT) could provide additional information on the activity distribution. This study investigates the feasibility and the image quality of simultaneous SPECT/CBCT, by means of phantom experiments and simulations. Simulations were performed to study the obtained reconstruction quality for (i) clinical SPECT/CT, (ii) a dual-layer scanner configured with optimized hardware, and (iii) our (non-optimized) dual-layer prototype. Experiments on an image quality phantom and an anthropomorphic phantom (including extrahepatic depositions with volumes and activities close to the median values encountered in hepatic radioembolization) were performed with a clinical SPECT/CT scanner and with our dual-layer prototype. Nuclear images were visually and quantitatively evaluated by measuring the tumor/non-tumor (T/N) ratio and contrast-to-noise ratio (CNR). The simulations showed that the maximum obtained CNR was 38.8 ± 0.8 for the clinical scanner, 30.2 ± 0.9 for the optimized dual-layer scanner, and 20.8 ± 0.4 for the prototype scanner. T/N ratio showed a similar decline. The phantom experiments showed that performing simultaneous SPECT/CBCT is feasible. The CNR obtained from the SPECT reconstruction of largest sphere in the image quality phantom was 43.1 for the clinical scanner and 28.6 for the developed prototype scanner. The anthropomorphic phantom showed that the extrahepatic depositions were detected with both scanners. A dual-layer detector is able to simultaneously acquire SPECT and CBCT. Both CNR and T/N ratio are worse than that of a clinical system, but the phantom experiments showed that extrahepatic depositions with volumes and activities close to the median values encountered in hepatic radioembolization could be distinguished.
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Affiliation(s)
- Martijn M A Dietze
- Radiology and Nuclear Medicine, Utrecht University and University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands. Image Sciences Institute, Utrecht University and University Medical Center Utrecht, PO Box 85500, 3508 GA, Utrecht, The Netherlands. Author to whom any correspondence should be addressed
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van der Velden S, Kunnen B, Koppert WJC, Steenbergen JHL, Dietze MMA, Beijst C, Viergever MA, Lam MGEH, de Jong HWAM. A Dual-layer Detector for Simultaneous Fluoroscopic and Nuclear Imaging. Radiology 2019; 290:833-838. [PMID: 30620257 DOI: 10.1148/radiol.2018180796] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Purpose To develop and evaluate a dual-layer detector capable of acquiring intrinsically registered real-time fluoroscopic and nuclear images in the interventional radiology suite. Materials and Methods The dual-layer detector consists of an x-ray flat panel detector placed in front of a γ camera with cone beam collimator focused at the x-ray focal spot. This design relies on the x-ray detector absorbing the majority of the x-rays while it is more transparent to the higher energy γ photons. A prototype was built and dynamic phantom images were acquired. In addition, spatial resolution and system sensitivity (evaluated as counts detected within the energy window per second per megabecquerel) were measured with the prototype. Monte Carlo simulations for an improved system with varying flat panel compositions were performed to assess potential spatial resolution and system sensitivity. Results Experiments with the dual-layer detector prototype showed that spatial resolution of the nuclear images was unaffected by the addition of the flat panel (full width at half maximum, 13.6 mm at 15 cm from the collimator surface). However, addition of the flat panel lowered system sensitivity by 45%-60% because of the nonoptimized transmission of the flat panel. Simulations showed that an attenuation of 27%-35% of the γ rays in the flat panel could be achieved by decreasing the crystal thickness and housing attenuation of the flat panel. Conclusion A dual-layer detector was capable of acquiring real-time intrinsically registered hybrid images, which could aid interventional procedures involving radionuclides. Published under a CC BY-NC-ND 4.0 license. Online supplemental material is available for this article.
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Affiliation(s)
- Sandra van der Velden
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Britt Kunnen
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Wilco J C Koppert
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Johannes H L Steenbergen
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Martijn M A Dietze
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Casper Beijst
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Max A Viergever
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Marnix G E H Lam
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
| | - Hugo W A M de Jong
- From the Department of Radiology and Nuclear Medicine (S.V.D.V., B.K., W.J.C.K., J.H.L.S., M.M.A.D., C.B., M.G.E.H.L., H.W.A.M.D.J.) and Image Sciences Institute (S.V.D.V., B.K., M.M.A.D., M.A.V.), University Medical Center Utrecht, Utrecht University, PO Box 85500, 3508 GA Utrecht, the Netherlands
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