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  1. Article ; Online: Complementary role of hybrid imaging with SPECT myocardial perfusion and coronary CT angiography in hypertrophic cardiomyopathy.

    Abazid, Rami M / Romsa, Jonathan G / Warrington, James C / Akincioglu, Cigdem / Stodilka, Robert Z / Vezina, William C

    Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology

    2021  Volume 29, Issue 5, Page(s) 2716–2720

    MeSH term(s) Cardiomyopathy, Hypertrophic/diagnostic imaging ; Computed Tomography Angiography/methods ; Coronary Angiography/methods ; Coronary Artery Disease/diagnostic imaging ; Humans ; Myocardial Perfusion Imaging/methods ; Perfusion ; Tomography, Emission-Computed, Single-Photon/methods
    Language English
    Publishing date 2021-01-06
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1212505-2
    ISSN 1532-6551 ; 1071-3581
    ISSN (online) 1532-6551
    ISSN 1071-3581
    DOI 10.1007/s12350-020-02497-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Coronary sinus to left atrium fistula on computed tomography angiography: Differentiation from unroofed coronary sinus with literature review.

    Abazid, Rami M / Goha, Ahmed / Romsa, Jonathan G / Warrington, James C / Akincioglu, Cigdem / Stodilka, Robert Z / Kiaii, Bob / Vezina, William C

    Journal of cardiovascular computed tomography

    2020  Volume 15, Issue 2, Page(s) e15–e17

    MeSH term(s) Computed Tomography Angiography ; Coronary Sinus/diagnostic imaging ; Coronary Vessel Anomalies ; Fistula ; Heart Atria/diagnostic imaging ; Heart Septal Defects, Atrial ; Humans ; Predictive Value of Tests
    Language English
    Publishing date 2020-11-13
    Publishing country United States
    Document type Case Reports ; Review
    ZDB-ID 2394360-9
    ISSN 1876-861X ; 1934-5925
    ISSN (online) 1876-861X
    ISSN 1934-5925
    DOI 10.1016/j.jcct.2020.11.003
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Boot-Shaped Heart After Robotic Coronary Assist Bypass Surgery.

    Abazid, Rami M / Akincioglu, Cigdem / Warrington, James C / Romsa, Jonathan G / Stodilka, Robert Z / Kiaii, Bob / Fox, Stephanie / Vezina, William C

    JACC. Cardiovascular imaging

    2020  Volume 13, Issue 11, Page(s) 2430–2434

    MeSH term(s) Coronary Artery Bypass ; Humans ; Predictive Value of Tests ; Robotic Surgical Procedures ; Robotics ; Treatment Outcome
    Language English
    Publishing date 2020-04-15
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2491503-8
    ISSN 1876-7591 ; 1936-878X
    ISSN (online) 1876-7591
    ISSN 1936-878X
    DOI 10.1016/j.jcmg.2020.01.028
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Hiatal hernia after robotic-assisted coronary artery bypass graft surgery.

    Abazid, Rami M / Khatami, Alireza / Romsa, Jonathan G / Warrington, James C / Akincioglu, Cigdem / Stodilka, Robert Z / Fox, Stephanie / Kiaii, Bob / Vezina, William C

    Journal of thoracic disease

    2021  Volume 13, Issue 2, Page(s) 575–581

    Abstract: Background: The aim of the present study is to determine the incidence/progression of hiatal hernia (HH) after robotic-assisted coronary artery bypass grafting (RA-CABG) surgery.: Methods: We reviewed the pre- and post-operative computed tomography ( ... ...

    Abstract Background: The aim of the present study is to determine the incidence/progression of hiatal hernia (HH) after robotic-assisted coronary artery bypass grafting (RA-CABG) surgery.
    Methods: We reviewed the pre- and post-operative computed tomography (CT) of 491 patients who underwent RA-CABG between 2000 and 2017. Post-operative CT was acquired prospectively in a research protocol. CT was reviewed to assess the presence and the size of HH.
    Results: We found 444/491 (90.4%) had pre-operative CT, while 201/491 (40.9%) had post-operative CT. In total, 155/491 (31.6%) had both pre- and long-term post-operative CT with a mean follow-up of 6.2 (±3.5) years. HH was more prevalent on post-operative CT, 64/155 (41.3%) compared to pre-operative CT, 44/155 (28.4%), P<0.0001. The diameter of pre-existing HH 2.8 (±1.8) cm was significantly greater after surgery 3.9 (±2.5) cm, P<0.0001. As well the volume of the pre-existing HH 5.8 (4.4-9.2) mL (quartile) was significantly greater after surgery 14.1 (7.2-64.9) mL, P<0.0001. 20/155 (12.9%) had a newly developed HH after RA-CABG. A binary multivariate regression including HH risk factors showed that male gender is a predictor of developing a HH after RA-CABG with Hazard Ratio of 3.038, confidence interval (1.10-8.43), P=0.033.
    Conclusions: RA-CABG is associated with an increased risk of developing HH and increases the size of pre-existing HH.
    Language English
    Publishing date 2021-02-24
    Publishing country China
    Document type Journal Article
    ZDB-ID 2573571-8
    ISSN 2077-6624 ; 2072-1439
    ISSN (online) 2077-6624
    ISSN 2072-1439
    DOI 10.21037/jtd-20-2557
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Tc-99m pyrophosphate left atrial uptake in patients with atrial fibrillation and cardiac amyloidosis.

    Abazid, Rami M / Romsa, Jonathan G / Warrington, James C / Stodilka, Robert Z / Davey, Ryan A / De, Sabe / Laidley, David L / Vezina, William C / Akincioglu, Cigdem

    Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology

    2021  Volume 29, Issue 5, Page(s) 2731–2733

    MeSH term(s) Amyloidosis/complications ; Amyloidosis/diagnostic imaging ; Atrial Fibrillation/complications ; Atrial Fibrillation/diagnostic imaging ; Cardiomyopathies/diagnostic imaging ; Diphosphates ; Heart ; Humans ; Technetium Tc 99m Pyrophosphate
    Chemical Substances Diphosphates ; Technetium Tc 99m Pyrophosphate (5L76I61H2B)
    Language English
    Publishing date 2021-01-27
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1212505-2
    ISSN 1532-6551 ; 1071-3581
    ISSN (online) 1532-6551
    ISSN 1071-3581
    DOI 10.1007/s12350-020-02508-3
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Variable lung density consideration in attenuation correction of whole-body PET/MRI.

    Marshall, Harry R / Prato, Frank S / Deans, Lela / Théberge, Jean / Thompson, R Terry / Stodilka, Robert Z

    Journal of nuclear medicine : official publication, Society of Nuclear Medicine

    2012  Volume 53, Issue 6, Page(s) 977–984

    Abstract: Unlabelled: Present attenuation-correction algorithms in whole-body PET/MRI do not consider variations in lung density, either within or between patients; this may adversely affect accurate quantification. In this work, a technique to incorporate ... ...

    Abstract Unlabelled: Present attenuation-correction algorithms in whole-body PET/MRI do not consider variations in lung density, either within or between patients; this may adversely affect accurate quantification. In this work, a technique to incorporate patient-specific lung density information into MRI-based attenuation maps is developed and compared with an approach that assumes uniform lung density.
    Methods: Five beagles were scanned with (18)F-FDG PET/CT and MRI. The relationship between MRI and CT signal in the lungs was established, allowing the prediction of attenuation coefficients from MRI. MR images were segmented into air, lung, and soft tissue and converted into attenuation maps, some with constant lung density and some with patient-specific lung densities. The resulting PET images were compared by both global metrics of quantitative fidelity (accuracy, precision, and root mean squared error) and locally with relative error in volumes of interest.
    Results: A linear relationship was established between MRI and CT signal in the lungs. Constant lung density attenuation maps did not perform as well as patient-specific lung density attenuation maps, regardless of what constant density was chosen. In particular, when attenuation maps with patient-specific lung density were used, precision, accuracy, and root mean square error improved in lung tissue. In volumes of interest placed in the lungs, relative error was significantly reduced from a minimum of 12% to less than 5%. The benefit extended to tissues adjacent to the lungs but became less important as distance from the lungs increased.
    Conclusion: A means of using MRI to infer patient-specific attenuation coefficients in the lungs was developed and applied to augment whole-body MRI-based attenuation maps. This technique has been shown to improve the quantitative fidelity of PET images in the lungs and nearby tissues, compared with an approach that assumes uniform lung density.
    MeSH term(s) Animals ; Dogs ; Female ; Lung/anatomy & histology ; Lung/diagnostic imaging ; Magnetic Resonance Imaging/methods ; Multimodal Imaging/methods ; Positron-Emission Tomography ; Tomography, X-Ray Computed ; Whole Body Imaging/methods
    Language English
    Publishing date 2012-06
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 80272-4
    ISSN 1535-5667 ; 0097-9058 ; 0161-5505 ; 0022-3123
    ISSN (online) 1535-5667
    ISSN 0097-9058 ; 0161-5505 ; 0022-3123
    DOI 10.2967/jnumed.111.098350
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Tracking transplanted cells using dual-radionuclide SPECT.

    Stodilka, Robert Z / Blackwood, Kimberly J / Prato, Frank S

    Physics in medicine and biology

    2006  Volume 51, Issue 10, Page(s) 2619–2632

    Abstract: The purpose of this study was to characterize the performance of single photon emission computed tomography (SPECT) in tasks associated with tracking transplanted cells. Previous studies identified matters of hardware design, whereas we focus on ... ...

    Abstract The purpose of this study was to characterize the performance of single photon emission computed tomography (SPECT) in tasks associated with tracking transplanted cells. Previous studies identified matters of hardware design, whereas we focus on biological variables impacting system performance, such as cell colony growth and non-specific radiolabelling. Using experimental data, a digital phantom was developed of in vitro 111In-radiolabelled stem cells, transfected with a reporter gene, transplanted into canine infarcted myocardium and interrogated using a peripherally injected 131I-radiolabelled reporter probe. Single- and dual-head SPECT acquisition was simulated. Performance was characterized using an estimation task, where the precision of parameter estimates (111In and 131I radiolabel quantity, cell colony size and location, and background) was tracked as the phantom evolved to simulate 111In-label efflux, cell colony growth and improved reporter probe specificity. In vitro pre-labelling of transplanted cells improved precision of parameter estimates via a priori size and location information. Precision of radiolabel quantity estimates improved with cell colony growth, despite 111In radiolabel dilution; size and location parameters were influenced little. Precision of radiolabel quantity estimates improved with reduced reporter probe non-specific uptake. The performance of SPECT in cell tracking is influenced strongly by biological variables. These should be considered when planning experiments or developing SPECT technology for cell tracking.
    MeSH term(s) Animals ; Cell Movement/physiology ; Cells, Cultured ; Humans ; Image Interpretation, Computer-Assisted/methods ; Iodine Radioisotopes ; Phantoms, Imaging ; Radiopharmaceuticals ; Reproducibility of Results ; Sensitivity and Specificity ; Stem Cell Transplantation/methods ; Stem Cells/diagnostic imaging ; Stem Cells/physiology ; Tomography, Emission-Computed, Single-Photon/instrumentation ; Tomography, Emission-Computed, Single-Photon/methods
    Chemical Substances Iodine Radioisotopes ; Radiopharmaceuticals
    Language English
    Publishing date 2006-05-21
    Publishing country England
    Document type Evaluation Studies ; Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 208857-5
    ISSN 1361-6560 ; 0031-9155
    ISSN (online) 1361-6560
    ISSN 0031-9155
    DOI 10.1088/0031-9155/51/10/017
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  8. Article ; Online: Singular value decomposition analysis of a photoacoustic imaging system and 3D imaging at 0.7 FPS.

    Roumeliotis, Michael B / Stodilka, Robert Z / Anastasio, Mark A / Ng, Eldon / Carson, Jeffrey J L

    Optics express

    2011  Volume 19, Issue 14, Page(s) 13405–13417

    Abstract: Photoacoustic imaging is a non-ionizing imaging modality that provides contrast consistent with optical imaging techniques while the resolution and penetration depth is similar to ultrasound techniques. In a previous publication [Opt. Express 18, 11406 ( ... ...

    Abstract Photoacoustic imaging is a non-ionizing imaging modality that provides contrast consistent with optical imaging techniques while the resolution and penetration depth is similar to ultrasound techniques. In a previous publication [Opt. Express 18, 11406 (2010)], a technique was introduced to experimentally acquire the imaging operator for a photoacoustic imaging system. While this was an important foundation for future work, we have recently improved the experimental procedure allowing for a more densely populated imaging operator to be acquired. Subsets of the imaging operator were produced by varying the transducer count as well as the measurement space temporal sampling rate. Examination of the matrix rank and the effect of contributing object space singular vectors to image reconstruction were performed. For a PAI system collecting only limited data projections, matrix rank increased linearly with transducer count and measurement space temporal sampling rate. Image reconstruction using a regularized pseudoinverse of the imaging operator was performed on photoacoustic signals from a point source, line source, and an array of point sources derived from the imaging operator. As expected, image quality increased for each object with increasing transducer count and measurement space temporal sampling rate. Using the same approach, but on experimentally sampled photoacoustic signals from a moving point-like source, acquisition, data transfer, reconstruction and image display took 1.4 s using one laser pulse per 3D frame. With relatively simple hardware improvements to data transfer and computation speed, our current imaging results imply that acquisition and display of 3D photoacoustic images at laser repetition rates of 10Hz is easily achieved.
    MeSH term(s) Algorithms ; Computer-Aided Design ; Elasticity Imaging Techniques/instrumentation ; Equipment Design ; Equipment Failure Analysis ; Image Interpretation, Computer-Assisted/instrumentation ; Image Interpretation, Computer-Assisted/methods ; Imaging, Three-Dimensional/instrumentation ; Phantoms, Imaging
    Language English
    Publishing date 2011-07-12
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1491859-6
    ISSN 1094-4087 ; 1094-4087
    ISSN (online) 1094-4087
    ISSN 1094-4087
    DOI 10.1364/OE.19.013405
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  9. Article ; Online: Technical Note: Comparison of megavoltage, dual-energy, and single-energy CT-based μ-maps for a four-channel breast coil in PET/MRI.

    Patrick, John C / Terry Thompson, R / So, Aaron / Butler, John / Faul, David / Stodilka, Robert Z / Yartsev, Slav / Prato, Frank S / Gaede, Stewart

    Medical physics

    2017  Volume 44, Issue 9, Page(s) 4758–4765

    Abstract: Purpose: The purpose of this study was to describe and evaluate methods for calculating a megavoltage computed tomography (MVCT)-derived MR hardware attenuation map (μ-map) and dual-energy CT (DECT) for 511 keV photons.: Methods: Phantom measurements ...

    Abstract Purpose: The purpose of this study was to describe and evaluate methods for calculating a megavoltage computed tomography (MVCT)-derived MR hardware attenuation map (μ-map) and dual-energy CT (DECT) for 511 keV photons.
    Methods: Phantom measurements were acquired on a whole-body hybrid PET/MRI system, using a four-channel receive-only MR radiofrequency (RF) breast coil. Two acquisitions were performed: with the phantoms positioned in the four-channel RF breast coil, and without the breast coil. PET attenuation from the breast coil was corrected using three different CT-derived hardware μ-maps: (a) Single-energy CT (SECT), (b) DECT, and (c) MVCT. Each attenuation-corrected (AC) PET volume was evaluated and compared with the acquisition performed without the breast coil.
    Results: The breast coil attenuated PET photons by 10% overall. Threshold values were applied to the SECT μ-map to reduce the effects of metal artifacts, but overcorrection occurred in more highly attenuated regions. The DECT-derived virtual monochromatic image reduced beam-hardening artifacts, but other metal artifacts remained. Despite the remaining metal artifacts in the DECT image, it led to an improvement in the more attenuated regions. The MVCT images appear to be free from metal artifacts leading to an artifact-free μ-map and a further improvement AC-PET images.
    Conclusions: Our MVCT-based approach for creating μ-maps for MR RF coils greatly reduces artifacts produced by metal in a SECT approach. This eliminates the need for other artifact reduction methods, including the application of a threshold of narrow beam attenuation coefficients, or disassembling hardware to remove high-Z components before imaging with a kilovoltage source.
    MeSH term(s) Artifacts ; Breast/diagnostic imaging ; Breast Neoplasms/diagnostic imaging ; Female ; Humans ; Magnetic Resonance Imaging ; Phantoms, Imaging ; Positron-Emission Tomography ; Tomography, X-Ray Computed
    Language English
    Publishing date 2017-09
    Publishing country United States
    Document type Journal Article
    ZDB-ID 188780-4
    ISSN 2473-4209 ; 0094-2405
    ISSN (online) 2473-4209
    ISSN 0094-2405
    DOI 10.1002/mp.12407
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  10. Article ; Online: Description and assessment of a registration-based approach to include bones for attenuation correction of whole-body PET/MRI.

    Marshall, Harry R / Patrick, John / Laidley, David / Prato, Frank S / Butler, John / Théberge, Jean / Thompson, R Terry / Stodilka, Robert Z

    Medical physics

    2013  Volume 40, Issue 8, Page(s) 82509

    Abstract: Purpose: Attenuation correction for whole-body PET/MRI is challenging. Most commercial systems compute the attenuation map from MRI using a four-tissue segmentation approach. Bones, the most electron-dense tissue, are neglected because they are ... ...

    Abstract Purpose: Attenuation correction for whole-body PET/MRI is challenging. Most commercial systems compute the attenuation map from MRI using a four-tissue segmentation approach. Bones, the most electron-dense tissue, are neglected because they are difficult to segment. In this work, the authors build on this segmentation approach by adding bones using a registration technique and assessing its performance on human PET images.
    Methods: Twelve oncology patients were imaged with FDG PET/CT and MRI using a Turbo-FLASH pulse sequence. A database of 121 attenuation correction quality CT scans was also collected. Each patient MRI was compared to the CT database via weighted heuristic measures to find the "most similar" CT in terms of body geometry. The similar CT was aligned to the MRI with a deformable registration method. Two MRI-based attenuation maps were computed. One was a standard four-tissue segmentation (air, lung, fat, and lean tissue) using basic image processing techniques. The other was identical, except the bones from the aligned CT were added. The PET data were reconstructed with the patient's CT-based attenuation map (the silver standard) and both MRI-based attenuation maps. The relative errors of the MRI-based attenuation corrections were computed in 14 standardized volumes of interest, in lesions, and over whole tissues. The squared Pearson correlation coefficient was also calculated over whole tissues. Statistical testing was done with ANOVAs and paired t-tests.
    Results: The MRI-based attenuation correction ignoring bone had relative errors ranging from -37% to -8% in volumes of interest containing bone. By including bone, the magnitude of the relative error was reduced in all cases (p<0.001), ranging from -3% to 4%. Further, the relative error in volumes of interest adjacent to bone was improved from a mean of -7.5% to 2% (p<0.001). In the other seven volumes of interest, including bone reduced the magnitude of relative error in three cases (p<0.001), had no effect in three cases, and increased relative error in one case. There was no statistically significant difference in the relative error in lesions. Over whole tissues, including bone slightly increased relative error in lung from 7.7% to 8.0% (p=0.002), in fat from 8.5% to 9.2% (p<0.001), and in lean tissue from -2.1% to 2.6% (p<0.001), but reduced the magnitude of relative error in bone from -14.6% to 1.3% (p<0.001). The correlation coefficient was essentially unchanged in all tissues regardless of whether bone was included or not.
    Conclusions: The approach to include bones in MRI-based attenuation maps described in this work improves quantification of whole-body PET images in and around bony anatomy. The reduction in error is often large (tens of percents), and could alter image interpretation and subsequent patient care. Changes in other parts of the PET image are minimal and likely not of clinical significance.
    MeSH term(s) Bone and Bones/diagnostic imaging ; Female ; Humans ; Image Processing, Computer-Assisted/methods ; Magnetic Resonance Imaging/methods ; Male ; Middle Aged ; Multimodal Imaging/methods ; Positron-Emission Tomography/methods ; Tomography, X-Ray Computed ; Whole Body Imaging/methods
    Language English
    Publishing date 2013-08
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 188780-4
    ISSN 2473-4209 ; 0094-2405
    ISSN (online) 2473-4209
    ISSN 0094-2405
    DOI 10.1118/1.4816301
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