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San Valentin EM, Damasco JA, Bernardino M, Court KA, Godin B, Canlas GM, Melancon A, Chintalapani G, Jacobsen MC, Norton W, Layman RR, Fowlkes N, Chen SR, Huang SY, Melancon MP. Image-Guided Deployment and Monitoring of a Novel Tungsten Nanoparticle-Infused Radiopaque Absorbable Inferior Vena Cava Filter in a Swine Model. J Vasc Interv Radiol 2024; 35:113-121.e3. [PMID: 37696432 PMCID: PMC10872373 DOI: 10.1016/j.jvir.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 08/30/2023] [Accepted: 09/03/2023] [Indexed: 09/13/2023] Open
Abstract
PURPOSE To improve radiopacity of radiolucent absorbable poly-p-dioxanone (PPDO) inferior vena cava filters (IVCFs) and demostrate their effectiveness in clot-trapping ability. MATERIALS AND METHODS Tungsten nanoparticles (WNPs) were incorporated along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of WNPs. The physicochemical and in vitro and in vivo imaging properties of PPDO IVCFs with WNPs with single-polymer PHB (W-P) were compared with those of WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB). RESULTS In vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physicomechanical properties of the PPDO sutures. W-P- and W-PB-coated IVCFs were deployed successfully into the inferior vena cava of pig models with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at Week 3 for both filters. CONCLUSIONS The results highlight the utility of nanoparticles (NPs) and polymers for enhancing radiopacity of medical devices. Different methods of incorporating NPs and polymers can still be explored to improve the effectiveness, safety, and quality of absorbable IVCFs.
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Affiliation(s)
- Erin Marie San Valentin
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jossana A Damasco
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Marvin Bernardino
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Karem A Court
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, Texas
| | - Biana Godin
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, Texas
| | | | - Adam Melancon
- Department of Radiation Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Megan C Jacobsen
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - William Norton
- Department of Veterinary Medicine and Surgery, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Rick R Layman
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Natalie Fowlkes
- Department of Veterinary Medicine and Surgery, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Stephen R Chen
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Steven Y Huang
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Marites P Melancon
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas.
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Thompson EA, Jacobsen MC, Fuentes DT, Layman RR, Cressman ENK. Quantitative dual-energy computed tomography with cesium as a novel contrast agent for localization of thermochemical ablation in phantoms and ex vivo models. Med Phys 2023; 50:7879-7890. [PMID: 37409792 PMCID: PMC10770302 DOI: 10.1002/mp.16558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 06/02/2023] [Accepted: 06/11/2023] [Indexed: 07/07/2023] Open
Abstract
BACKGROUND Thermochemical ablation (TCA) is a minimally invasive therapy under development for hepatocellular carcinoma. TCA simultaneously delivers an acid (acetic acid, AcOH) and base (sodium hydroxide, NaOH) directly into the tumor, where the acid/base chemical reaction produces an exotherm that induces local ablation. However, AcOH and NaOH are not radiopaque, making monitoring TCA delivery difficult. PURPOSE We address the issue of image guidance for TCA by utilizing cesium hydroxide (CsOH) as a novel theranostic component of TCA that is detectable and quantifiable with dual-energy CT (DECT). MATERIALS AND METHODS To quantify the minimum concentration of CsOH that can be positively identified by DECT, the limit of detection (LOD) was established in an elliptical phantom (Multi-Energy CT Quality Assurance Phantom, Kyoto Kagaku, Kyoto, Japan) with two DECT technologies: a dual-source system (SOMATOM Force, Siemens Healthineers, Forchheim, Germany) and a split-filter, single-source system (SOMATOM Edge, Siemens Healthineers). The dual-energy ratio (DER) and LOD of CsOH were determined for each system. Cesium concentration quantification accuracy was evaluated in a gelatin phantom before quantitative mapping was performed in ex vivo models. RESULTS On the dual-source system, the DER and LOD were 2.94 and 1.36-mM CsOH, respectively. For the split-filter system, the DER and LOD were 1.41- and 6.11-mM CsOH, respectively. The signal on cesium maps in phantoms tracked linearly with concentration (R2 = 0.99) on both systems with an RMSE of 2.56 and 6.72 on the dual-source and split-filter system, respectively. In ex vivo models, CsOH was detected following delivery of TCA at all concentrations. CONCLUSIONS DECT can be used to detect and quantify the concentration of cesium in phantom and ex vivo tissue models. When incorporated in TCA, CsOH performs as a theranostic agent for quantitative DECT image-guidance.
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Affiliation(s)
- Emily A Thompson
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Megan C Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - David T Fuentes
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Rick R Layman
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Erik N K Cressman
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Jacobsen MC, Rigaud B, Simiele SJ, Rauch GM, Ning MS, Vedam S, Klopp AH, Stafford RJ, Brock KK, Venkatesan AM. Feasibility of quantitative diffusion-weighted imaging during intra-procedural MRI-guided brachytherapy of locally advanced cervical and vaginal cancers. Brachytherapy 2023; 22:736-745. [PMID: 37612174 DOI: 10.1016/j.brachy.2023.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/30/2023] [Accepted: 06/15/2023] [Indexed: 08/25/2023]
Abstract
PURPOSE To determine the feasibility of quantitative apparent diffusion coefficient (ADC) acquisition during magnetic resonance imaging-guided brachytherapy (MRgBT) using reduced field-of-view (rFOV) diffusion-weighted imaging (DWI). METHODS AND MATERIALS T2-weighted (T2w) MR and full-FOV single-shot echo planar (ssEPI) DWI were acquired in 7 patients with cervical or vaginal malignancy at baseline and prior to brachytherapy, while rFOV-DWI was acquired during MRgBT following brachytherapy applicator placement. The gross target volume (GTV) was contoured on the T2w images and registered to the ADC map. Voxels at the GTV's maximum Maurer distance comprised a central sub-volume (GTVcenter). Contour ADC mean and standard deviation were compared between timepoints using repeated measures ANOVA. RESULTS ssEPI-DWI mean ADC increased between baseline and prebrachytherapy from 1.03 ± 0.18 10-3 mm2/s to 1.34 ± 0.28 10-3 mm2/s for the GTV (p = 0.06) and from 0.84 ± 0.13 10-3 mm2/s to 1.26 ± 0.25 10-3 mm2/s at the level of the GTVcenter (p = 0.03), consistent with early treatment response. rFOV-DWI during MRgBT demonstrated mean ADC values of 1.28 ± 0.14 10-3 mm2/s and 1.28 ± 0.19 10-3 mm2/s for the GTV and GTVcenter, respectively (p = 0.02 and p = 0.03 relative to baseline). No significant differences were observed between ssEPI-DWI and rFOV-DWI ADC measurements. CONCLUSIONS Quantitative ADC measurement in the setting of MRI guided brachytherapy implant placement for cervical and vaginal cancers is feasible using rFOV-DWI, with comparable mean ADC comparable to prebrachytherapy ssEPI-DWI, and may enable MRI-guided radiotherapy targeting of low ADC, radiation resistant sub-volumes of tumor.
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Affiliation(s)
- Megan C Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX.
| | - Bastien Rigaud
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Samantha J Simiele
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Gaiane M Rauch
- Department of Abdominal Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Matthew S Ning
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Sastry Vedam
- University of Maryland, Department of Radiation Oncology, Baltimore, MD
| | - Ann H Klopp
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - R Jason Stafford
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Kristy K Brock
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX; Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX
| | - Aradhana M Venkatesan
- Department of Abdominal Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX.
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Jacobsen MC, Maheshwari E, Klopp AH, Venkatesan AM. Image-Guided Radiotherapy for Gynecologic Malignancies: What the Radiologist Needs to Know. Radiol Clin North Am 2023; 61:725-747. [PMID: 37169434 DOI: 10.1016/j.rcl.2023.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Pelvic imaging is integral to contemporary radiotherapy (RT) management of gynecologic malignancies. For cervical, endometrial, vulvar, and vaginal cancers, three-dimensional imaging modalities aid in tumor staging and RT candidate selection and inform treatment strategy, including RT planning, execution, and posttherapy surveillance. State-of-the-art care routinely incorporates magnetic resonance (MR) imaging, 18F-fluorodeoxyglucose-PET/computed tomography (CT), and CT to guide external beam RT and brachytherapy, allowing the customization of RT plans to maximize patient outcomes and reduce treatment-related toxicities. Follow-up imaging identifies radiation-resistant and recurrent disease as well as short-term and long-term toxicities from RT.
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Affiliation(s)
- Megan C Jacobsen
- Division of Diagnostic Imaging, Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Unit 1472, Houston, TX 77030, USA. https://twitter.com/megjacobsen
| | - Ekta Maheshwari
- Division of Abdominal Imaging, Department of Radiology, University of Pittsburgh Medical Center, PUH Suite E204, 200 Lothrop St, Pittsburgh, PA 15213, USA. https://twitter.com/dr_ektam
| | - Ann H Klopp
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Houston, TX 77030, USA. https://twitter.com/AnnKloppMD
| | - Aradhana M Venkatesan
- Division of Diagnostic Imaging, Department of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Unit 1473, Houston, TX 77030, USA.
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Thompson EA, Fowlkes NW, Jacobsen MC, Layman RR, Cressman ENK. Quantitative Dual-Energy CT Image Guidance for Thermochemical Ablation: In Vivo Results in the Rabbit VX2 Model. J Vasc Interv Radiol 2023; 34:782-789. [PMID: 36539151 PMCID: PMC10542852 DOI: 10.1016/j.jvir.2022.12.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/07/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
PURPOSE To evaluate the feasibility of using dual-energy computed tomography (CT) and theranostic cesium hydroxide (CsOH) for image guidance of thermochemical ablation (TCA) in a rabbit VX2 tumor model. MATERIALS AND METHODS In vivo experiments were performed on New Zealand white rabbits, where VX2 tumor fragments (0.3 mL) were inoculated into the right and left flanks (n = 16 rabbits, 32 tumors). Catheters were placed in the approximate center of 1- to 2-cm diameter tumors under ultrasound guidance. TCA was delivered in 1 of 3 treatment groups: untreated control, 5-M TCA, or 10-M TCA. The TCA base reagent was doped with 250-mM CsOH. Dual-energy CT was performed before and after TCA. Cesium (CS)-specific images were postprocessed on the basis of previous phantom calibrations to determine Cs concentration. Line profiles were drawn through the ablation center. Twenty-four hours after TCA, subjects were euthanized, and the resulting damage was evaluated with histopathology. RESULTS Cs was detected in 100% of treated tumors (n = 21). Line profiles indicated highest concentrations at the injection site and decreased concentrations at the tumor margins, with no Cs detected beyond the ablation zone. The maximum detected Cs concentration ranged from 14.39 to 137.33 mM. A dose-dependent trend in tissue necrosis was demonstrated between the 10-M TCA and 5-M TCA treatment groups (P = .0005) and untreated controls (P = .0089). CONCLUSIONS Dual-energy CT provided image guidance for delivery, localization, and quantification of TCA in the rabbit VX2 model.
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Affiliation(s)
- Emily A Thompson
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Natalie W Fowlkes
- Department of Veterinary Medicine and Surgery, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Megan C Jacobsen
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Rick R Layman
- Department of Imaging Physics, the University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Erik N K Cressman
- Department of Interventional Radiology, the University of Texas MD Anderson Cancer Center, Houston, Texas.
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San Valentin EM, Damasco JA, Bernardino M, Court KA, Godin B, Canlas GM, Melancon A, Chintalapani G, Jacobsen MC, Norton W, Layman RR, Fowlkes N, Chen SR, Huang SY, Melancon MP. Image-guided deployment and monitoring of a novel tungsten nanoparticleâ€"infused radiopaque absorbable inferior vena cava filter in pigs. bioRxiv 2023:2023.02.06.527049. [PMID: 36798362 PMCID: PMC9934538 DOI: 10.1101/2023.02.06.527049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The use of absorbable inferior vena cava filters (IVCFs) constructed with poly-p-dioxanone (PPDO) eliminates risks and complications associated with the use of retrievable metallic filters. Radiopacity of radiolucent PPDO IVCFs can be improved with the incorporation of nanoparticles (NPs) made of high-atomic number materials such as gold and bismuth. In this study, we focused on incorporating tungsten NPs (WNPs), along with polyhydroxybutyrate (PHB), polycaprolactone (PCL), and polyvinylpyrrolidone (PVP) polymers to increase the surface adsorption of the WNPs. We compared the imaging properties of WNPs with single-polymer PHB (W-P) and WNPs with polymer blends consisting of PHB, PCL, and PVP (W-PB). Our in vitro analyses using PPDO sutures showed enhanced radiopacity with either W-P or W-PB coating, without compromising the inherent physico-mechanical properties of the PPDO sutures. We observed a more sustained release of WNPs from W-PB-coated sutures than W-P-coated sutures. We successfully deployed W-P- and W-PB-coated IVCFs into the inferior vena cava of pig models, with monitoring by fluoroscopy. At the time of deployment, W-PB-coated IVCFs showed a 2-fold increase in radiopacity compared to W-P-coated IVCFs. Longitudinal monitoring of in vivo IVCFs over a 12-week period showed a drastic decrease in radiopacity at week 3 for both filters. Results of this study highlight the utility of NPs and polymers for enhancing radiopacity of medical devices; however, different methods of incorporating NPs and polymers can still be explored to improve the efficacy, safety, and quality of absorbable IVCFs.
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Simiele S, Starks C, Jacobsen MC, Venkatesan AM, Klopp AH, Colbert L. PO42 Presentation Time: 4:45 PM. Brachytherapy 2022. [DOI: 10.1016/j.brachy.2022.09.148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Simiele S, Jacobsen MC, Bruno T, Venkatesan AM, Lin L, Colbert L, Klopp AH. PO24 Presentation Time: 7:40 AM. Brachytherapy 2022. [DOI: 10.1016/j.brachy.2022.09.130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Jacobsen MC, Beriwal S, Dyer BA, Klopp AH, Lee SI, McGinnis GJ, Robbins JB, Rauch GM, Sadowski EA, Simiele SJ, Stafford RJ, Taunk NK, Yashar CM, Venkatesan AM. Contemporary image-guided cervical cancer brachytherapy: Consensus imaging recommendations from the Society of Abdominal Radiology and the American Brachytherapy Society. Brachytherapy 2022; 21:369-388. [PMID: 35725550 DOI: 10.1016/j.brachy.2022.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/15/2022] [Accepted: 04/24/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE To present recommendations for the use of imaging for evaluation and procedural guidance of brachytherapy for cervical cancer patients. METHODS An expert panel comprised of members of the Society of Abdominal Radiology Uterine and Ovarian Cancer Disease Focused Panel and the American Brachytherapy Society jointly assessed the existing literature and provide data-driven guidance on imaging protocol development, interpretation, and reporting. RESULTS Image-guidance during applicator implantation reduces rates of uterine perforation by the tandem. Postimplant images may be acquired with radiography, computed tomography (CT), or magnetic resonance imaging (MRI), and CT or MRI are preferred due to a decrease in severe complications. Pre-brachytherapy T2-weighted MRI may be used as a reference for contouring the high-risk clinical target volume (HR-CTV) when CT is used for treatment planning. Reference CT and MRI protocols are provided for reference. CONCLUSIONS Image-guided brachytherapy in locally advanced cervical cancer is essential for optimal patient management. Various imaging modalities, including orthogonal radiographs, ultrasound, computed tomography, and magnetic resonance imaging, remain integral to the successful execution of image-guided brachytherapy.
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Affiliation(s)
- Megan C Jacobsen
- The University of Texas MD Anderson Cancer Center, Department of Imaging Physics, Houston, TX
| | - Sushil Beriwal
- Allegheny Health Network, Department of Radiation Oncology, Pittsburgh, PA; Varian Medical Systems, Palo Alto, CA
| | - Brandon A Dyer
- Legacy Health, Department of Radiation Oncology, Portland, OR
| | - Ann H Klopp
- The University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, TX
| | - Susanna I Lee
- Massachusetts General Hospital, Department of Radiology, Boston, MA
| | - Gwendolyn J McGinnis
- The University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, TX
| | | | - Gaiane M Rauch
- The University of Texas MD Anderson Cancer Center, Department of Abdominal Imaging, Houston, TX
| | | | - Samantha J Simiele
- The University of Texas MD Anderson Cancer Center, Department of Radiation Physics, Houston, TX
| | - R Jason Stafford
- The University of Texas MD Anderson Cancer Center, Department of Imaging Physics, Houston, TX
| | - Neil K Taunk
- University of Pennsylvania, Department of Radiation Oncology, Philadelphia, PA
| | - Catheryn M Yashar
- University of California San Diego, Department of Radiation Oncology, San Diego, CA
| | - Aradhana M Venkatesan
- The University of Texas MD Anderson Cancer Center, Department of Abdominal Imaging, Houston, TX.
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Damasco JA, Huang SY, Perez JVD, Manongdo JAT, Dixon KA, Williams ML, Jacobsen MC, Barbosa R, Canlas GM, Chintalapani G, Melancon AD, Layman RR, Fowlkes NW, Whitley EM, Melancon MP. Bismuth Nanoparticle and Polyhydroxybutyrate Coatings Enhance the Radiopacity of Absorbable Inferior Vena Cava Filters for Fluoroscopy-Guided Placement and Longitudinal Computed Tomography Monitoring in Pigs. ACS Biomater Sci Eng 2022; 8:1676-1685. [PMID: 35343679 PMCID: PMC9045416 DOI: 10.1021/acsbiomaterials.1c01449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Inferior vena cava filters (IVCFs) constructed with poly-p-dioxanone (PPDO) are promising alternatives to metallic filters and their associated risks and complications. Incorporating high-Z nanoparticles (NPs) improves PPDO IVCFs' radiopacity without adversely affecting their safety or performance. However, increased radiopacity from these studies are insufficient for filter visualization during fluoroscopy-guided PPDO IVCF deployment. This study focuses on the use of bismuth nanoparticles (BiNPs) as radiopacifiers to render sufficient signal intensity for the fluoroscopy-guided deployment and long-term CT monitoring of PPDO IVCFs. The use of polyhydroxybutyate (PHB) as an additional layer to increase the surface adsorption of NPs resulted in a 2-fold increase in BiNP coating (BiNP-PPDO IVCFs, 3.8%; BiNP-PPDO + PHB IVCFs, 6.2%), enabling complete filter visualization during fluoroscopy-guided IVCF deployment and, 1 week later, clot deployment. The biocompatibility, clot-trapping efficacy, and mechanical strength of the control PPDO (load-at-break, 6.23 ± 0.13 kg), BiNP-PPDO (6.10 ± 0.09 kg), and BiNP-PPDO + PHB (6.15 ± 0.13 kg) IVCFs did not differ significantly over a 12-week monitoring period in pigs. These results indicate that BiNP-PPDO + PHB can increase the radiodensity of a novel absorbable IVCF without compromising device strength. Visualizing the device under conventional radiographic imaging is key to allow safe and effective clinical translation of the device.
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Affiliation(s)
- Jossana A Damasco
- Departments of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Steven Y Huang
- Departments of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Joy Vanessa D Perez
- Departments of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | | | - Katherine A Dixon
- Departments of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Malea L Williams
- Departments of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Megan C Jacobsen
- Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Roland Barbosa
- Covalent Metrology Sunnyvale, Sunnyvale, California 94085, United States
| | - Gino Martin Canlas
- Department of Chemistry, Lamar University, Beaumont, Texas 77710, United States
| | | | - Adam D Melancon
- Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Rick R Layman
- Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Natalie W Fowlkes
- Veterinary Medicine and Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Elizabeth M Whitley
- Veterinary Medicine and Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
| | - Marites P Melancon
- Departments of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
- UT Health Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, United States
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Abstract
Dual-energy CT (DECT) imaging is a technique that extends the capabilities of CT beyond that of established densitometric evaluations. CT pulmonary angiography (CTPA) performed with dual-energy technique benefits from both the availability of low kVp CT data and also the concurrent ability to quantify iodine enhancement in the lung parenchyma. Parenchymal enhancement, presented as pulmonary perfused blood volume maps, may be considered as a surrogate of pulmonary perfusion. These distinct capabilities have led to new opportunities in the evaluation of pulmonary vascular diseases. Dual-energy CTPA offers the potential for improvements in pulmonary emboli detection, diagnostic confidence, and most notably severity stratification. Furthermore, the appreciated insights of pulmonary vascular physiology conferred by DECT have resulted in increased use for the assessment of pulmonary hypertension, with particular utility in the subset of patients with chronic thromboembolic pulmonary hypertension. With the increasing availability of dual energy-capable CT systems, dual energy CTPA is becoming a standard-of-care protocol for CTPA acquisition in acute PE. Furthermore, qualitative and quantitative pulmonary vascular DECT data heralds promise for the technique as a "one-stop shop" for diagnosis and surveillance assessment in patients with pulmonary hypertension. This review explores the current application, clinical value, and limitations of DECT imaging in acute and chronic pulmonary vascular conditions. It should be noted that certain manufacturers and investigators prefer alternative terms, such as spectral or multi-energy CT imaging. In this review, the term dual energy is utilised, although readers can consider these terms synonymous for purposes of the principles explained.
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Affiliation(s)
- Ioannis Vlahos
- Department of Thoracic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Megan C Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Myrna C Godoy
- Department of Thoracic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Rick R Layman
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Ahmad M, Jacobsen MC, Thomas MA, Chen HS, Layman RR, Jones AK. A Benchmark for automatic noise measurement in clinical computed tomography. Med Phys 2020; 48:640-647. [PMID: 33283284 DOI: 10.1002/mp.14635] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 11/15/2020] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Assessment of image quality directly in clinical image data is an important quality control objective as phantom-based testing does not fully represent image quality across patient variation. Computer algorithms for automatically measuring noise in clinical computed tomography (CT) images have been introduced, but the accuracy of these algorithms is unclear. This work benchmarks the accuracy of the global noise (GN) algorithm for automatic noise measurement in contrast-enhanced abdomen CT exams in comparison to precise reference noise measurements. The GN algorithm was further optimized compared to the previous report in the literature. METHODS Reference values of noise were established in a public image dataset of 82 contrast-enhanced abdomen CT exams. The reference noise values were obtained by manual regions-of-interest measurements of pixel standard deviation in the liver parenchyma according to an instruction protocol. Noise measurements taken by six observers were averaged together to improve reference noise statistical precision. The GN algorithm was used to automatically measure noise in each image set. The accuracy of the GN algorithm was determined in terms of RMS error compared to reference noise. The GN algorithm was optimized by conducting 1000 trials with random algorithm parameter values. The trial with the lowest RMS error was used to select optimum algorithm parameters. RESULTS The range of noise across CT image sets was 8.8-28.8 HU. Reference noise measurements were made with a precision of ±0.78 HU (95% confidence interval). The RMS error of automatic noise measurement was 0.93 HU (0.77-1.19 HU 95% confidence interval). The automatic noise measurements were equally accurate across image sets of varying noise magnitude. Optimum GN algorithm parameter values were: a kernel size of 7 pixels, and soft tissue lower and upper thresholds of 0 and 170 HU, respectively. CONCLUSIONS The performance of automatic noise measurement was benchmarked in a large clinical CT dataset. The study provides a framework for thorough validation of automatic clinical image quality measurement methods. The GN algorithm was optimized and validated for automatic measurement of soft-tissue noise in abdomen CT exams.
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Affiliation(s)
- Moiz Ahmad
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Megan C Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - M Allan Thomas
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Henry S Chen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Rick R Layman
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - A Kyle Jones
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
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13
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Perez JVD, Jacobsen MC, Damasco JA, Melancon A, Huang SY, Layman RR, Melancon MP. Optimization of the differentiation and quantification of high-Z nanoparticles incorporated in medical devices for CT-guided interventions. Med Phys 2020; 48:300-312. [PMID: 33216978 DOI: 10.1002/mp.14601] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 01/18/2023] Open
Abstract
PURPOSE Material differentiation has been made possible using dual-energy computed tomography (DECT), in which the unique, energy-dependent attenuating characteristics of materials can provide new diagnostic information. One promising application is the clinical integration of biodegradable polymers as temporary implantable medical devices impregnated with high-atomic number (high-Z) materials. The purpose of this study was to explore the incorporation of high atomic number (high-Z) contrast materials in a bioresorbable inferior vena cava filter for advanced CT-based monitoring of its location and differentiating from surrounding materials. MATERIALS AND METHODS Imaging optimization and calibration studies were performed using a body phantom. The dual-energy CT (DECT) ratios for iron, zirconium, barium, gadolinium, ytterbium, tantalum, tungsten, gold, and bismuth were generated for peak kilovoltage combinations of 80/150Sn, 90/150Sn, and 100/150Sn kVp in dual-source CT via linear regression of the CT numbers at low and high energies. A secondary calibration of the material map to the nominal material concentration was generated to correct for use of materials other than iodine. CT number was calibrated to the material concentration based on single-energy CT (SECT) with additional filtration (150Sn kVp). These quantification methods were applied to monitoring of biodegradable inferior vena cava filters (IVCFs) made of braided poly(p-dioxanone) sutures infused with ultrasmall bismuth nanoparticles (BiNPs) implanted in an adult domestic pig. RESULTS Qualitative material differentiation was optimal for high-Z (>73) contrast agents in DECT. However, quantification became nonlinear and inaccurate as the K-edge of the material increased. Using the high-energy (150Sn kVp) data component as a SECT scan, the linearity of quantification curves was maintained with lower limits of detection than with DECT. Among the materials tested, bismuth had optimal differentiation from iodine in DECT while maintaining increased contrast in high-energy SECT for quantification (11.5% error). Coating the IVCF with BiNPs resulted in markedly greater radiopacity (maximum CT number, 2028 HU) than that of an uncoated IVCF (maximum CT number, 127 HU). Using DECT imaging and processing, the BiNP-IVCF could be clearly differentiated from iodine contrast injected into the inferior vena cava of the pig. CONCLUSIONS These findings may improve widespread integration of medical devices incorporated with high-Z materials into the clinic, where technical success, possible complications, and device integrity can be assessed intraoperatively and postoperatively via DECT imaging.
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Affiliation(s)
- Joy Vanessa D Perez
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- College of Medicine, University of the Philippines Manila, Manila, Philippines
| | - Megan C Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jossana A Damasco
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Adam Melancon
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Steven Y Huang
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Rick R Layman
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Marites P Melancon
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
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Jacobsen MC, Thrower SL. Multi-energy computed tomography and material quantification: Current barriers and opportunities for advancement. Med Phys 2020; 47:3752-3771. [PMID: 32453879 PMCID: PMC8495770 DOI: 10.1002/mp.14241] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 04/20/2020] [Accepted: 05/07/2020] [Indexed: 12/21/2022] Open
Abstract
Computed tomography (CT) technology has rapidly evolved since its introduction in the 1970s. It is a highly important diagnostic tool for clinicians as demonstrated by the significant increase in utilization over several decades. However, much of the effort to develop and advance CT applications has been focused on improving visual sensitivity and reducing radiation dose. In comparison to these areas, improvements in quantitative CT have lagged behind. While this could be a consequence of the technological limitations of conventional CT, advanced dual-energy CT (DECT) and photon-counting detector CT (PCD-CT) offer new opportunities for quantitation. Routine use of DECT is becoming more widely available and PCD-CT is rapidly developing. This review covers efforts to address an unmet need for improved quantitative imaging to better characterize disease, identify biomarkers, and evaluate therapeutic response, with an emphasis on multi-energy CT applications. The review will primarily discuss applications that have utilized quantitative metrics using both conventional and DECT, such as bone mineral density measurement, evaluation of renal lesions, and diagnosis of fatty liver disease. Other topics that will be discussed include efforts to improve quantitative CT volumetry and radiomics. Finally, we will address the use of quantitative CT to enhance image-guided techniques for surgery, radiotherapy and interventions and provide unique opportunities for development of new contrast agents.
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Affiliation(s)
- Megan C. Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sara L. Thrower
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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15
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Huang SY, Damasco JA, Tian L, Lu L, Perez JVD, Dixon KA, Williams ML, Jacobsen MC, Dria SJ, Eggers MD, Melancon AD, Layman RR, Whitley EM, Melancon MP. In vivo performance of gold nanoparticle-loaded absorbable inferior vena cava filters in a swine model. Biomater Sci 2020; 8:3966-3978. [PMID: 32558854 PMCID: PMC7386069 DOI: 10.1039/d0bm00414f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Absorbable inferior vena cava filters (IVCFs) offer a promising alternative to metallic retrievable filters in providing protection against pulmonary embolism (PE) for patients contraindicated for anticoagulant therapy. However, because absorbable filters are not radiopaque, monitoring of the filter using conventional X-ray imaging modalities (e.g. plain film radiographs, computed tomography [CT] and fluoroscopy) during deployment and follow-up is not possible and represents a potential obstacle to widespread clinical integration of the device. Here, we demonstrate that gold nanoparticles (AuNPs) infused into biodegradable filters made up of poly-p-dioxanone (PPDO) may improve device radiopacity without untoward effects on device efficacy and safety, as assessed in swine models for 12 weeks. The absorbable AuNP-infused filters demonstrated significantly improved visualization using CT without affecting tensile strength, in vitro degradation, in vivo resorption, or thrombus-capturing efficacy, as compared to similar non-AuNPs infused resorbable IVCFs. This study presents a significant advancement to the development of imaging enhancers for absorbable IVCFs.
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Affiliation(s)
- Steven Y Huang
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA.
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Le Roux LG, Qiu X, Jacobsen MC, Pagel MD, Gammon ST, R. Piwnica-Worms D, Schellingerhout D. Axonal Transport as an In Vivo Biomarker for Retinal Neuropathy. Cells 2020; 9:cells9051298. [PMID: 32456061 PMCID: PMC7291064 DOI: 10.3390/cells9051298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 02/03/2023] Open
Abstract
We illuminate a possible explanatory pathophysiologic mechanism for retinal cellular neuropathy by means of a novel diagnostic method using ophthalmoscopic imaging and a molecular imaging agent targeted to fast axonal transport. The retinal neuropathies are a group of diseases with damage to retinal neural elements. Retinopathies lead to blindness but are typically diagnosed late, when substantial neuronal loss and vision loss have already occurred. We devised a fluorescent imaging agent based on the non-toxic C fragment of tetanus toxin (TTc), which is taken up and transported in neurons using the highly conserved fast axonal transport mechanism. TTc serves as an imaging biomarker for normal axonal transport and demonstrates impairment of axonal transport early in the course of an N-methyl-D-aspartic acid (NMDA)-induced excitotoxic retinopathy model in rats. Transport-related imaging findings were dramatically different between normal and retinopathic eyes prior to presumed neuronal cell death. This proof-of-concept study provides justification for future clinical translation.
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Affiliation(s)
- Lucia G. Le Roux
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (X.Q.); (M.D.P.); (S.T.G.); (D.R.P.-W.)
- Correspondence: ; Tel.: +713-563-5338
| | - Xudong Qiu
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (X.Q.); (M.D.P.); (S.T.G.); (D.R.P.-W.)
| | - Megan C. Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
| | - Mark D. Pagel
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (X.Q.); (M.D.P.); (S.T.G.); (D.R.P.-W.)
| | - Seth T. Gammon
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (X.Q.); (M.D.P.); (S.T.G.); (D.R.P.-W.)
| | - David R. Piwnica-Worms
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX 77054, USA; (X.Q.); (M.D.P.); (S.T.G.); (D.R.P.-W.)
| | - Dawid Schellingerhout
- Department of Neuroradiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
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17
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Javadi S, Elsherif S, Bhosale P, Jensen CT, Layman RR, Jacobsen MC, Le O, Jia S, Parikh RJ, Tamm EP. Quantitative attenuation accuracy of virtual non-enhanced imaging compared to that of true non-enhanced imaging on dual-source dual-energy CT. Abdom Radiol (NY) 2020; 45:1100-1109. [PMID: 32052130 DOI: 10.1007/s00261-020-02415-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To evaluate the quantitative attenuation and reliability of virtual non-contrast (VNC) images of the abdomen acquired from multiphasic scans with a dual-energy computed tomography (DECT) system and compare it with that of true non-enhanced images (TNC) on second- (Flash) and third- (Force) generation DECT scanners. METHODS This retrospective study was approved by the institutional review board and included 123 patients with pancreatic cancer who had undergone routine clinical multiphasic DECT examinations at our institution using Flash and Force scanners between March and August 2017. VNC images of the abdomen were reconstructed from late arterial phase images. For every patient, regions-of-interest were defined in the aorta, fluid-containing structures (gallbladder, pleural effusion, and renal cysts > 10 mm), paravertebral muscles, subcutaneous fat, spleen, pancreas, renal cortex, and liver (eight locations) on TNC and VNC images. The mean attenuation of VNC was compared with TNC by organ for each CT scanner using an equivalence test and the Bland-Altman plot. The mean attenuations for TNC or VNC were compared between the Force and Flash CT scanners using a two-sample t test. RESULTS The VNC attenuation of organs on the Force scanner was lower than was that on the Flash, and the mean attenuation difference in different organs on the Force was closer to 0. The estimated means of TNC and VNC were equivalent for an equivalence margin of 10 on the Force scanner. CONCLUSION VNC images in DECT are a promising alternative to TNC images. In clinical scenarios in which non-enhanced CT images are required but are not available for accurate diagnosis, VNC images can potentially serve as an alternative to TNC images without the radiation exposure risks.
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18
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Jacobsen MC, Cressman ENK, Tamm EP, Baluya DL, Duan X, Cody DD, Schellingerhout D, Layman RR. Dual-Energy CT: Lower Limits of Iodine Detection and Quantification. Radiology 2019; 292:414-419. [PMID: 31237496 PMCID: PMC6694721 DOI: 10.1148/radiol.2019182870] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/12/2019] [Accepted: 05/01/2019] [Indexed: 01/30/2023]
Abstract
Background Assessments of the quantitative limitations among the six commercially available dual-energy (DE) CT acquisition schemes used by major CT manufacturers could aid researchers looking to use iodine quantification as an imaging biomarker. Purpose To determine the limits of detection and quantification of DE CT in phantoms by comparing rapid peak kilovoltage switching, dual-source, split-filter, and dual-layer detector systems in six different scanners. Materials and Methods Seven 50-mL iohexol solutions were used, with concentrations of 0.03-2.0 mg iodine per milliliter. The solutions and water sample were scanned five times each in two phantoms (small, 20-cm diameter; large, 30 × 40-cm diameter) with six DE CT systems and a total of 10 peak kilovoltage settings or combinations. Iodine maps were created, and the mean iodine signal in each sample was recorded. The limit of blank (LOB) was defined as the upper limit of the 95% confidence interval of the water sample. The limit of detection (LOD) was defined as the concentration with a 95% chance of having a signal above the LOB. The limit of quantification (LOQ) was defined as the lowest concentration where the coefficient of variation was less than 20%. Results The LOD range was 0.021-0.26 mg/mL in the small phantom and 0.026-0.55 mg/mL in the large phantom. The LOQ range was 0.07-0.50 mg/mL in the small phantom and 0.20-1.0 mg/mL in the large phantom. The dual-source and rapid peak kilovoltage switching systems had the lowest LODs, and the dual-layer detector systems had the highest LODs. Conclusion The iodine limit of detection using dual-energy CT systems varied with scanner and phantom size, but all systems depicted iodine in the small and large phantoms at or below 0.3 and 0.5 mg/mL, respectively, and enabled quantification at concentrations of 0.5 and 1.0 mg/mL, respectively. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Hindman in this issue.
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Affiliation(s)
- Megan C. Jacobsen
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
| | - Erik N. K. Cressman
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
| | - Eric P. Tamm
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
| | - Dodge L. Baluya
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
| | - Xinhui Duan
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
| | - Dianna D. Cody
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
| | - Dawid Schellingerhout
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
| | - Rick R. Layman
- From the Departments of Imaging Physics (M.C.J., D.D.C., R.R.L.),
Interventional Radiology (E.N.K.C., D.L.B.), Diagnostic Radiology, Abdominal
Imaging Section (E.P.T.), and Diagnostic Radiology, Neuroradiology Section
(D.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd,
Houston, TX 77030; and Radiology, Medical Physics Section (X.D.), University of
Texas Southwestern Medical Center, Dallas, Tex
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Ger RB, Yang J, Ding Y, Jacobsen MC, Cardenas CE, Fuller CD, Howell RM, Li H, Stafford RJ, Zhou S, Court LE. Synthetic head and neck and phantom images for determining deformable image registration accuracy in magnetic resonance imaging. Med Phys 2018; 45:10.1002/mp.13090. [PMID: 30007075 PMCID: PMC6331282 DOI: 10.1002/mp.13090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 05/07/2018] [Accepted: 05/15/2018] [Indexed: 02/01/2023] Open
Abstract
PURPOSE Magnetic resonance imaging (MRI) provides noninvasive evaluation of patient's anatomy without using ionizing radiation. Due to this and the high soft-tissue contrast, MRI use has increased and has potential for use in longitudinal studies where changes in patients' anatomy or tumors at different time points are compared. Deformable image registration can be useful for these studies. Here, we describe two datasets that can be used to evaluate the registration accuracy of systems for MR images, as it cannot be assumed to be the same as that measured on CT images. ACQUISITION AND VALIDATION METHODS Two sets of images were created to test registration accuracy. (a) A porcine phantom was created by placing ten 0.35-mm gold markers into porcine meat. The porcine phantom was immobilized in a plastic container with movable dividers. T1-weighted, T2-weighted, and CT images were acquired with the porcine phantom compressed in four different ways. The markers were not visible on the MR images, due to the selected voxel size, so they did not interfere with the measured registration accuracy, while the markers were visible on the CT images and were used to identify the known deformation between positions. (b) Synthetic images were created using 28 head and neck squamous cell carcinoma patients who had MR scans pre-, mid-, and postradiotherapy treatment. An inter- and intrapatient variation model was created using these patient scans. Four synthetic pretreatment images were created using the interpatient model, and four synthetic post-treatment images were created for each of the pretreatment images using the intrapatient model. DATA FORMAT AND USAGE NOTES The T1-weighted, T2-weighted, and CT scans of the porcine phantom in the four positions are provided. Four T1-weighted synthetic pretreatment images each with four synthetic post-treatment images, and four T2-weighted synthetic pretreatment images each with four synthetic post-treatment images are provided. Additionally, the applied deformation vector fields to generate the synthetic post-treatment images are provided. The data are available on TCIA under the collection MRI-DIR. POTENTIAL APPLICATIONS The proposed database provides two sets of images (one acquired and one computer generated) for use in evaluating deformable image registration accuracy. T1- and T2-weighted images are available for each technique as the different image contrast in the two types of images may impact the registration accuracy.
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Affiliation(s)
- Rachel B. Ger
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Jinzhong Yang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Yao Ding
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Megan C. Jacobsen
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Carlos E. Cardenas
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Clifton D. Fuller
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Rebecca M. Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Heng Li
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - R. Jason Stafford
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Shouhao Zhou
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Laurence E. Court
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Nute JL, Jacobsen MC, Stefan W, Wei W, Cody DD. Development of a dual-energy computed tomography quality control program: Characterization of scanner response and definition of relevant parameters for a fast-kVp switching dual-energy computed tomography system. Med Phys 2018; 45:1444-1458. [PMID: 29446082 DOI: 10.1002/mp.12812] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 12/17/2022] Open
Abstract
PURPOSE A prototype QC phantom system and analysis process were developed to characterize the spectral capabilities of a fast kV-switching dual-energy computed tomography (DECT) scanner. This work addresses the current lack of quantitative oversight for this technology, with the goal of identifying relevant scan parameters and test metrics instrumental to the development of a dual-energy quality control (DEQC). METHODS A prototype elliptical phantom (effective diameter: 35 cm) was designed with multiple material inserts for DECT imaging. Inserts included tissue equivalent and material rods (including iodine and calcium at varying concentrations). The phantom was scanned on a fast kV-switching DECT system using 16 dual-energy acquisitions (CTDIvol range: 10.3-62 mGy) with varying pitch, rotation time, and tube current. The circular head phantom (22 cm diameter) was scanned using a similar protocol (12 acquisitions; CTDIvol range: 36.7-132.6 mGy). All acquisitions were reconstructed at 50, 70, 110, and 140 keV and using a water-iodine material basis pair. The images were evaluated for iodine quantification accuracy, stability of monoenergetic reconstruction CT number, noise, and positional constancy. Variance component analysis was used to identify technique parameters that drove deviations in test metrics. Variances were compared to thresholds derived from manufacturer tolerances to determine technique parameters that had a nominally significant effect on test metrics. RESULTS Iodine quantification error was largely unaffected by any of the technique parameters investigated. Monoenergetic HU stability was found to be affected by mAs, with a threshold under which spectral separation was unsuccessful, diminishing the utility of DECT imaging. Noise was found to be affected by CTDIvol in the DEQC body phantom, and CTDIvol and mA in the DEQC head phantom. Positional constancy was found to be affected by mAs in the DEQC body phantom and mA in the DEQC head phantom. CONCLUSION A streamlined scan protocol was developed to further investigate the effects of CTDIvol and rotation time while limiting data collection to the DEQC body phantom. Further data collection will be pursued to determine baseline values and statistically based failure thresholds for the validation of long-term DECT scanner performance.
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Affiliation(s)
- Jessica L Nute
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Megan C Jacobsen
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Medical Physics Program, The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Wolfgang Stefan
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Wei Wei
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Dianna D Cody
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
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21
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Tian L, Lee P, Singhana B, Chen A, Qiao Y, Lu L, Martinez J, Tasciotti E, Jacobsen MC, Melancon A, McArthur M, Eggers M, Huang S, Melancon MP. In vivo imaging of radiopaque resorbable inferior vena cava filter infused with gold nanoparticles. Proc SPIE Int Soc Opt Eng 2018; 10576. [PMID: 31406393 DOI: 10.1117/12.2293738] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Radiopaque resorbable inferior vena cava filter (IVCF) were developed to offer a less expensive alternative to assessing filter integrity in preventing pulmonary embolism for the recommended prophylactic period and then simply vanishes without intervention. In this study, we determined the efficacy of gold nanoparticle (AuNP)-infused poly-p-dioxanone (PPDO) as an IVCF in a swine model. Infusion into PPDO loaded 1.14±0.08 % AuNP by weight as determined by elemental analysis. The infusion did not alter PPDO's mechanical strength nor crystallinity (Kruskal-Wallis one-way ANOVA, p<0.05). There was no cytotoxicity observed (one-way ANOVA, p<0.05) when tested against RF24 and MRC5 cells. Gold content in PPDO was maintained at ~2000 ppm during the 6-week incubation in PBS at 37°C. As a proof-of-concept, two pigs were deployed with IVCF, one with AuNP-PPDO and the other without coating. Results show that the stent ring of AuNP-PPDO was highly visible even in the presence of iodine-based contrast agent and after clot introduction, but not of the uncoated IVCF. Autopsy at two weeks post-implantation showed AuNP-PPDO filter was endothelialized onto the IVC wall, and no sign of filter migration was observed. The induced clot was also still trapped within the AuNP-PPDO IVCF. As a conclusion, we successfully fabricated AuNP-infused PPDO IVCF that is radiopaque, has robust mechanical strength, biocompatible, and can be imaged effectively in vivo. This suggests the efficacy of this novel, radiopaque, absorbable IVCF for monitoring its position and integrity over time, thus increasing the safety and efficacy of deep vein thrombosis treatment.
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Affiliation(s)
- Li Tian
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Patrick Lee
- College of Medicine, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
| | - Burapol Singhana
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Innovative Nanomedicine Research Unit, Chulabhorn International College of Medicine, Thammasat University, Rangsit Campus, Pathum Thani, Thailand 12120
| | - Aaron Chen
- Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yang Qiao
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Linfeng Lu
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Jonathan Martinez
- Center for Biomimetic Medicine, Houston Methodist, Houston, TX 77030, USA
| | - Ennio Tasciotti
- Center for Biomimetic Medicine, Houston Methodist, Houston, TX 77030, USA
| | - Megan C Jacobsen
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Adam Melancon
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Mark McArthur
- Department of Veterinary Medicine The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | - Steve Huang
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Marites P Melancon
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.,Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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22
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Weinersmith KL, Brown CE, Clingen KB, Jacobsen MC, Topper LB, Hechinger RF. Euhaplorchis californiensis Cercariae Exhibit Positive Phototaxis and Negative Geotaxis. J Parasitol 2018; 104:329-333. [PMID: 29381420 DOI: 10.1645/17-80] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Parasites often use external cues to identify and move toward environments where they are likely to encounter suitable hosts. The trematode parasite Euhaplorchis californiensis produces cercariae that emerge from California horn snails ( Cerithideopsis californica [= Cerithidea californica]) to infect California killifish ( Fundulus parvipinnis) as second intermediate hosts. Based upon work on a congeneric Euhaplorchis species from Florida, and based on the ecology of its killifish host, we hypothesized that E. californiensis cercariae in southern California estuaries are positively phototactic and negatively geotactic, using both sunlight and gravity to guide their movement to the upper water column. To distinguish positive phototaxis from negative geotaxis, we first quantified E. californiensis movement in response to light along a horizontal plane and determined they were positively phototactic. In a second experiment, we quantified E. californiensis movement along a vertical plane in response to an overhead light, a light from below, or no light. We found that E. californiensis exhibit negative geotaxis in the absence of light, but will swim in the direction of gravity to move toward a light source from below. Thus, E. californiensis are both positively phototactic and negatively geotactic, but cercariae prioritize phototactic cues. These results suggest that E. californiensis cercariae aggregate in the open water, indicating that the pelagic zone represents an area of high infection risk for California killifish hosts.
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Affiliation(s)
- K L Weinersmith
- 1 BioSciences Department, 6100 Main Street, Rice University, Houston, Texas 77005
| | - C E Brown
- 1 BioSciences Department, 6100 Main Street, Rice University, Houston, Texas 77005
| | - K B Clingen
- 1 BioSciences Department, 6100 Main Street, Rice University, Houston, Texas 77005
| | - M C Jacobsen
- 1 BioSciences Department, 6100 Main Street, Rice University, Houston, Texas 77005
| | - L B Topper
- 1 BioSciences Department, 6100 Main Street, Rice University, Houston, Texas 77005
| | - R F Hechinger
- 2 Scripps Institution of Oceanography-Marine Biology Research Division, University of California, San Diego, La Jolla, California 92093
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23
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Jacobsen MC, Schellingerhout D, Wood CA, Tamm EP, Godoy MC, Sun J, Cody DD. Intermanufacturer Comparison of Dual-Energy CT Iodine Quantification and Monochromatic Attenuation: A Phantom Study. Radiology 2017; 287:224-234. [PMID: 29185902 DOI: 10.1148/radiol.2017170896] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Purpose To determine the accuracy of dual-energy computed tomographic (CT) quantitation in a phantom system comparing fast kilovolt peak-switching, dual-source, split-filter, sequential-scanning, and dual-layer detector systems. Materials and Methods A large elliptical phantom containing iodine (2, 5, and 15 mg/mL), simulated contrast material-enhanced blood, and soft-tissue inserts with known elemental compositions was scanned three to five times with seven dual-energy CT systems and a total of 10 kilovolt peak settings. Monochromatic images (50, 70, and 140 keV) and iodine concentration images were created. Mean iodine concentration and monochromatic attenuation for each insert and reconstruction energy level were recorded. Measurement bias was assessed by using the sum of the mean signed errors measured across relevant inserts for each monochromatic energy level and iodine concentration. Iodine and monochromatic errors were assessed by using the root sum of the squared error of all measurements. Results At least one acquisition paradigm per scanner had iodine biases (range, -2.6 to 1.5 mg/mL) with significant differences from zero. There were no significant differences in iodine error (range, 0.44-1.70 mg/mL) among the top five acquisition paradigms (one fast kilovolt peak switching, three dual source, and one sequential scanning). Monochromatic bias was smallest for 70 keV (-12.7 to 15.8 HU) and largest for 50 keV (-80.6 to 35.2 HU). There were no significant differences in monochromatic error (range, 11.4-52.0 HU) among the top three acquisition paradigms (one dual source and two fast kilovolt peak switching). The lowest accuracy for both measures was with a split-filter system. Conclusion Iodine and monochromatic accuracy varies among systems, but dual-source and fast kilovolt-switching generally provided the most accurate results in a large phantom. © RSNA, 2017 Online supplemental material is available for this article.
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Affiliation(s)
- Megan C Jacobsen
- From the Department of Imaging Physics (M.C.J., C.A.W., D.D.C.), Department of Diagnostic Radiology, Sections of Neuroradiology (D.S.), Abdominal Imaging (E.P.T.), and Thoracic Imaging (M.C.G.), and Department of Biostatistics (J.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030
| | - Dawid Schellingerhout
- From the Department of Imaging Physics (M.C.J., C.A.W., D.D.C.), Department of Diagnostic Radiology, Sections of Neuroradiology (D.S.), Abdominal Imaging (E.P.T.), and Thoracic Imaging (M.C.G.), and Department of Biostatistics (J.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030
| | - Cayla A Wood
- From the Department of Imaging Physics (M.C.J., C.A.W., D.D.C.), Department of Diagnostic Radiology, Sections of Neuroradiology (D.S.), Abdominal Imaging (E.P.T.), and Thoracic Imaging (M.C.G.), and Department of Biostatistics (J.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030
| | - Eric P Tamm
- From the Department of Imaging Physics (M.C.J., C.A.W., D.D.C.), Department of Diagnostic Radiology, Sections of Neuroradiology (D.S.), Abdominal Imaging (E.P.T.), and Thoracic Imaging (M.C.G.), and Department of Biostatistics (J.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030
| | - Myrna C Godoy
- From the Department of Imaging Physics (M.C.J., C.A.W., D.D.C.), Department of Diagnostic Radiology, Sections of Neuroradiology (D.S.), Abdominal Imaging (E.P.T.), and Thoracic Imaging (M.C.G.), and Department of Biostatistics (J.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030
| | - Jia Sun
- From the Department of Imaging Physics (M.C.J., C.A.W., D.D.C.), Department of Diagnostic Radiology, Sections of Neuroradiology (D.S.), Abdominal Imaging (E.P.T.), and Thoracic Imaging (M.C.G.), and Department of Biostatistics (J.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030
| | - Dianna D Cody
- From the Department of Imaging Physics (M.C.J., C.A.W., D.D.C.), Department of Diagnostic Radiology, Sections of Neuroradiology (D.S.), Abdominal Imaging (E.P.T.), and Thoracic Imaging (M.C.G.), and Department of Biostatistics (J.S.), The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030
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24
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Ger RB, Yang J, Ding Y, Jacobsen MC, Fuller CD, Howell RM, Li H, Jason Stafford R, Zhou S, Court LE. Accuracy of deformable image registration on magnetic resonance images in digital and physical phantoms. Med Phys 2017. [PMID: 28622410 DOI: 10.1002/mp.12406] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Accurate deformable image registration is necessary for longitudinal studies. The error associated with commercial systems has been evaluated using computed tomography (CT). Several in-house algorithms have been evaluated for use with magnetic resonance imaging (MRI), but there is still relatively little information about MRI deformable image registration. This work presents an evaluation of two deformable image registration systems, one commercial (Velocity) and one in-house (demons-based algorithm), with MRI using two different metrics to quantify the registration error. METHODS The registration error was analyzed with synthetic MR images. These images were generated from interpatient and intrapatient variation models trained on 28 patients. Four synthetic post-treatment images were generated for each of four synthetic pretreatment images, resulting in 16 image registrations for both the T1- and T2-weighted images. The synthetic post-treatment images were registered to their corresponding synthetic pretreatment image. The registration error was calculated between the known deformation vector field and the generated deformation vector field from the image registration system. The registration error was also analyzed using a porcine phantom with ten implanted 0.35-mm diameter gold markers. The markers were visible on CT but not MRI. CT, T1-weighted MR, and T2-weighted MR images were taken in four different positions. The markers were contoured on the CT images and rigidly registered to their corresponding MR images. The MR images were deformably registered and the distance between the projected marker location and true marker location was measured as the registration error. RESULTS The synthetic images were evaluated only on Velocity. Root mean square errors (RMSEs) of 0.76 mm in the left-right (LR) direction, 0.76 mm in the anteroposterior (AP) direction, and 0.69 mm in the superior-inferior (SI) direction were observed for the T1-weighted MR images. RMSEs of 1.1 mm in the LR direction, 0.75 mm in the AP direction, and 0.81 mm in the SI direction were observed for the T2-weighted MR images. The porcine phantom MR images, when evaluated with Velocity, had RMSEs of 1.8, 1.5, and 2.7 mm in the LR, AP, and SI directions for the T1-weighted images and 1.3, 1.2, and 1.6 mm in the LR, AP, and SI directions for the T2-weighted images. When the porcine phantom images were evaluated with the in-house demons-based algorithm, RMSEs were 1.2, 1.5, and 2.1 mm in the LR, AP, and SI directions for the T1-weighted images and 0.81, 1.1, and 1.1 mm in the LR, AP, and SI directions for the T2-weighted images. CONCLUSIONS The MRI registration error was low for both Velocity and the in-house demons-based algorithm according to both image evaluation methods, with all RMSEs below 3 mm. This implies that both image registration systems can be used for longitudinal studies using MRI.
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Affiliation(s)
- Rachel B Ger
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Jinzhong Yang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Yao Ding
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Megan C Jacobsen
- UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Clifton D Fuller
- UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Rebecca M Howell
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Heng Li
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - R Jason Stafford
- UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Shouhao Zhou
- UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Laurence E Court
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.,UTHealth Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.,Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
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25
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Jacobsen MC, Dusart PJ, Kotowicz K, Bajaj-Elliott M, Hart SL, Klein NJ, Dixon GL. A critical role for ATF2 transcription factor in the regulation of E-selectin expression in response to non-endotoxin components of Neisseria meningitidis. Cell Microbiol 2015; 18:66-79. [PMID: 26153406 PMCID: PMC4973847 DOI: 10.1111/cmi.12483] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 06/26/2015] [Accepted: 07/05/2015] [Indexed: 01/15/2023]
Abstract
Vascular injury is a serious complication of sepsis due to the gram‐negative bacterium Neisseria meningitidis. One of the critical early steps in initiating this injury is via the interaction of leucocytes, particularly neutrophils, with adhesion molecules expressed on inflamed endothelium. We have previously demonstrated that both lipopolysaccharide (LPS) and non‐LPS components of meningococci can induce very high levels of expression of the vascular endothelial cell adhesion molecule E‐selectin, which is critical for early tethering and capture of neutrophils onto endothelium under flow. Using an LPS‐deficient strain of meningococcus, we showed that very high levels of expression can be induced in primary endothelial cells, even in the context of weak activation of the major host signal transduction factor [nuclear factor‐κB (NF‐κB)]. In this study, we show that the particular propensity for N. meningitidis to induce high levels of expression is regulated at a transcriptional level, and demonstrate a significant role for phosphorylation of the ATF2 transcription factor, likely via mitogen‐activated protein (MAP) kinases, on the activity of the E‐selectin promoter. Furthermore, inhibition of E‐selectin expression in response to the lpxA− strain by a p38 inhibitor indicates a significant role of a p38‐dependent MAPK signalling pathway in ATF2 activation. Collectively, these data highlight the role that LPS and other bacterial components have in modulating endothelial function and their involvement in the pathogenesis of meningococcal sepsis. Better understanding of these multiple mechanisms induced by complex stimuli such as bacteria, and the specific inflammatory pathways they activate, may lead to improved, focused interventions in both meningococcal and potentially bacterial sepsis more generally.
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Affiliation(s)
- M C Jacobsen
- Infection, Inflammation and Rheumatology Section, Institute of Child Health, University College London, London, UK.,Department of Biology, Faculty of Science, University of Regina, Regina, SK, Canada
| | - P J Dusart
- Infection, Inflammation and Rheumatology Section, Institute of Child Health, University College London, London, UK.,Science for Life Laboratory, Clinical Applied Proteomics, School of Biotechnology, Royal Institute of Technology (KTH), Solna, Sweden
| | - K Kotowicz
- Infection, Inflammation and Rheumatology Section, Institute of Child Health, University College London, London, UK
| | - M Bajaj-Elliott
- Infection, Inflammation and Rheumatology Section, Institute of Child Health, University College London, London, UK
| | - S L Hart
- Experimental and Personalised Medicine Section, Institute of Child Health, University College London, London, UK
| | - N J Klein
- Infection, Inflammation and Rheumatology Section, Institute of Child Health, University College London, London, UK
| | - G L Dixon
- Infection, Inflammation and Rheumatology Section, Institute of Child Health, University College London, London, UK.,Department of Microbiology, Great Ormond Street Hospital, London, UK
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Abstract
PURPOSE To determine relationships among patient size, scanner radiation output, and size-specific dose estimates (SSDEs) for adults who underwent computed tomography (CT) of the torso. MATERIALS AND METHODS Informed consent was waived for this institutional review board-approved study of existing data from 545 adult patients (322 men, 223 women) who underwent clinically indicated CT of the torso between April 1, 2007, and May 13, 2007. Automatic exposure control was used to adjust scanner output for each patient according to the measured CT attenuation. The volume CT dose index (CTDI(vol)) was used with measurements of patient size (anterioposterior plus lateral dimensions) and the conversion factors from the American Association of Physicists in Medicine Report 204 to determine SSDE. Linear regression models were used to assess the dependence of CTDI(vol) and SSDE on patient size. RESULTS Patient sizes ranged from 42 to 84 cm. In this range,CTDI(vol) was significantly correlated with size (slope = 0.34 mGy/cm; 95% confidence interval [CI]: 0.31, 0.37 mGy/cm; R(2) = 0.48; P < .001), but SSDE was independent of size (slope = 0.02 mGy/cm; 95% CI: -0.02, 0.07 mGy/cm; R(2) = 0.003; P = .3). These R(2) values indicated that patient size explained 48% of the observed variability in CTDI(vol) but less than 1% of the observed variability in SSDE. The regression of CTDI(vol) versus patient size demonstrated that, in the 42-84-cm range, CTDI(vol) varied from 12 to 26 mGy. However, use of the evaluated automatic exposure control system to adjust scanner output for patient size resulted in SSDE values that were independent of size. CONCLUSION For the evaluated automatic exposure control system,CTDI(vol) (scanner output) increased linearly with patient size; however, patient dose (as indicated by SSDE) was independent of size.
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Affiliation(s)
- Jodie A Christner
- Department of Radiology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
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27
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Abstract
A 10-year-old female spayed domestic shorthaired cat presented with a subcutaneous tumor between the first and second phalanges of the left hind foot. Six months after excision, a similar tumor occurred on the medial aspect of the third phalanx of the same limb. Histologically, both tumors consisted of solid masses of spindle and round cells, many of which grew within endothelial-lined vessels. Tumor cells stained positively for smooth muscle actin and vimentin, but were negative for cytokeratin, S-100, desmin, synaptophysin, factor VIII-related antigen, and neuron-specific enolase. The diagnosis was dermal intravascular leiomyosarcoma.
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Affiliation(s)
- M C Jacobsen
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
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Abstract
Lesions consistent with exertional myopathy (EM) were documented postmortem in four North American river otters (Lutra canadensis) during translocation for a population restoration project. Clinical signs in these otters included depression, anorexia and shock. Gross lesions in one otter included locally extensive linear, pale areas within the subscapularis, rectus abdominis, quadriceps, and dorsal laryngeal muscles. Microscopic lesions were characterized by acute to subacute myofiber necrosis of varying severity, and occurred in a variety of skeletal muscles as well as cardiac muscle in one otter. Based on these observations, we conducted a retrospective review of records of otters which experienced similar capture, transfer, and holding protocols between 1995 and 1997, but with a successful outcome (n = 69). Significant elevations in serum aspartate aminotransferase (AST) and creatine kinase (CK) were observed in 19 (28%) of the otters, but may have been higher due to delayed sample collection from some otters. However, none of the otters with elevated enzymes exhibited clinical signs suggestive of EM. These findings indicate that river otters may develop EM when translocated, but many cases may be mild or clinically inapparent.
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Affiliation(s)
- B K Hartup
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
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Abstract
A magnetic position and orientation tracking system is currently available for the determination of the position and orientation of a sensor relative to a source by utilizing the principle of low-frequency magnetic field technology. The application of this system for biomechanical analysis of human movement is examined in this study. Studies of both planar particle motion and spatial rigid body motion based on Eulerian angle description and screw displacement axis description have been performed. The system has been found to be quite accurate and easy to use, and it would be a useful tool in kinesiologic research.
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Affiliation(s)
- K N An
- Department of Orthopedics, Mayo Clinic, Rochester, MN 55905
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