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van Praagh GD, Nienhuis PH, Reijrink M, Davidse MEJ, Duff LM, Spottiswoode BS, Mulder DJ, Prakken NHJ, Scarsbrook AF, Morgan AW, Tsoumpas C, Wolterink JM, Mouridsen KB, Borra RJH, Sinha B, Slart RHJA. Automated multiclass segmentation, quantification, and visualization of the diseased aorta on hybrid PET/CT-SEQUOIA. Med Phys 2024. [PMID: 38323867 DOI: 10.1002/mp.16967] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 11/10/2023] [Accepted: 01/16/2024] [Indexed: 02/08/2024] Open
Abstract
BACKGROUND Cardiovascular disease is the most common cause of death worldwide, including infection and inflammation related conditions. Multiple studies have demonstrated potential advantages of hybrid positron emission tomography combined with computed tomography (PET/CT) as an adjunct to current clinical inflammatory and infectious biochemical markers. To quantitatively analyze vascular diseases at PET/CT, robust segmentation of the aorta is necessary. However, manual segmentation is extremely time-consuming and labor-intensive. PURPOSE To investigate the feasibility and accuracy of an automated tool to segment and quantify multiple parts of the diseased aorta on unenhanced low-dose computed tomography (LDCT) as an anatomical reference for PET-assessed vascular disease. METHODS A software pipeline was developed including automated segmentation using a 3D U-Net, calcium scoring, PET uptake quantification, background measurement, radiomics feature extraction, and 2D surface visualization of vessel wall calcium and tracer uptake distribution. To train the 3D U-Net, 352 non-contrast LDCTs from (2-[18 F]FDG and Na[18 F]F) PET/CTs performed in patients with various vascular pathologies with manual segmentation of the ascending aorta, aortic arch, descending aorta, and abdominal aorta were used. The last 22 consecutive scans were used as a hold-out internal test set. The remaining dataset was randomly split into training (n = 264; 80%) and validation (n = 66; 20%) sets. Further evaluation was performed on an external test set of 49 PET/CTs. The dice similarity coefficient (DSC) and Hausdorff distance (HD) were used to assess segmentation performance. Automatically obtained calcium scores and uptake values were compared with manual scoring obtained using clinical softwares (syngo.via and Affinity Viewer) in six patient images. intraclass correlation coefficients (ICC) were calculated to validate calcium and uptake values. RESULTS Fully automated segmentation of the aorta using a 3D U-Net was feasible in LDCT obtained from PET/CT scans. The external test set yielded a DSC of 0.867 ± 0.030 and HD of 1.0 [0.6-1.4] mm, similar to an open-source model with a DSC of 0.864 ± 0.023 and HD of 1.4 [1.0-1.8] mm. Quantification of calcium and uptake values were in excellent agreement with clinical software (ICC: 1.00 [1.00-1.00] and 0.99 [0.93-1.00] for calcium and uptake values, respectively). CONCLUSIONS We present an automated pipeline to segment the ascending aorta, aortic arch, descending aorta, and abdominal aorta on LDCT from PET/CT and to accurately provide uptake values, calcium scores, background measurement, radiomics features, and a 2D visualization. We call this algorithm SEQUOIA (SEgmentation, QUantification, and visualizatiOn of the dIseased Aorta) and is available at https://github.com/UMCG-CVI/SEQUOIA. This model could augment the utility of aortic evaluation at PET/CT studies tremendously, irrespective of the tracer, and potentially provide fast and reliable quantification of cardiovascular diseases in clinical practice, both for primary diagnosis and disease monitoring.
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Affiliation(s)
- Gijs D van Praagh
- Medical Imaging Center, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Pieter H Nienhuis
- Medical Imaging Center, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Melanie Reijrink
- Department of Internal Medicine, division of Vascular Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Mirjam E J Davidse
- Department of Applied Mathematics and Technical Medicine Center, University of Twente, Enschede, the Netherlands
| | - Lisa M Duff
- Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, UK
| | | | - Douwe J Mulder
- Department of Internal Medicine, division of Vascular Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Niek H J Prakken
- Medical Imaging Center, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Andy F Scarsbrook
- University of Leeds, School of Medicine, Leeds, UK
- NIHR Leeds Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust, Leeds, UK
- NIHR Leeds Medtech and In vitro Diagnostics Co-operative, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Ann W Morgan
- University of Leeds, School of Medicine, Leeds, UK
- NIHR Leeds Biomedical Research Centre, Leeds Teaching Hospitals NHS Trust, Leeds, UK
- NIHR Leeds Medtech and In vitro Diagnostics Co-operative, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Charalampos Tsoumpas
- Medical Imaging Center, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, UK
| | - Jelmer M Wolterink
- Department of Applied Mathematics and Technical Medicine Center, University of Twente, Enschede, the Netherlands
| | - Kim B Mouridsen
- Medical Imaging Center, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Ronald J H Borra
- Medical Imaging Center, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Department of Diagnostic Radiology, Turku University Hospital, Turku, Finland
| | - Bhanu Sinha
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Riemer H J A Slart
- Medical Imaging Center, Department of Nuclear Medicine & Molecular Imaging, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Department of Biomedical Photonic Imaging, University of Twente, Enschede, the Netherlands
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Ferreira PF, Nielles-Vallespin S, Scott AD, de Silva R, Kilner PJ, Ennis DB, Auger DA, Suever JD, Zhong X, Spottiswoode BS, Pennell DJ, Arai AE, Firmin DN. Evaluation of the impact of strain correction on the orientation of cardiac diffusion tensors with in vivo and ex vivo porcine hearts. Magn Reson Med 2017; 79:2205-2215. [PMID: 28734017 DOI: 10.1002/mrm.26850] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [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: 03/20/2017] [Revised: 06/07/2017] [Accepted: 07/02/2017] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate the importance of strain-correcting stimulated echo acquisition mode echo-planar imaging cardiac diffusion tensor imaging. METHODS Healthy pigs (n = 11) were successfully scanned with a 3D cine displacement-encoded imaging with stimulated echoes and a monopolar-stimulated echo-planar imaging diffusion tensor imaging sequence at 3 T during diastasis, peak systole, and strain sweet spots in a midventricular short-axis slice. The same diffusion tensor imaging sequence was repeated ex vivo after arresting the hearts in either a relaxed (KCl-induced) or contracted (BaCl2 -induced) state. The displacement-encoded imaging with stimulated echoes data were used to strain-correct the in vivo cardiac diffusion tensor imaging in diastole and systole. The orientation of the primary (helix angles) and secondary (E2A) diffusion eigenvectors was compared with and without strain correction and to the strain-free ex vivo data. RESULTS Strain correction reduces systolic E2A significantly when compared without strain correction and ex vivo (median absolute E2A = 34.3° versus E2A = 57.1° (P = 0.01), E2A = 60.5° (P = 0.006), respectively). The systolic distribution of E2A without strain correction is closer to the contracted ex vivo distribution than with strain correction, root mean square deviation of 0.027 versus 0.038. CONCLUSIONS The current strain-correction model amplifies the contribution of microscopic strain to diffusion resulting in an overcorrection of E2A. Results show that a new model that considers cellular rearrangement is required. Magn Reson Med 79:2205-2215, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Pedro F Ferreira
- Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom.,National Heart and Lung Institute, Imperial College, London, United Kingdom
| | | | - Andrew D Scott
- Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom.,National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Ranil de Silva
- Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom.,National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Philip J Kilner
- Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom.,National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Daniel B Ennis
- Department of Radiological Sciences, University of California, Los Angeles, California, USA
| | - Daniel A Auger
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | | | | | | | - Dudley J Pennell
- Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom.,National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Andrew E Arai
- NHLBI, National Institutes of Health, Bethesda, Maryland, USA
| | - David N Firmin
- Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom.,National Heart and Lung Institute, Imperial College, London, United Kingdom
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Keller EJ, Fang S, Lin K, Freed BH, Smith PM, Spottiswoode BS, Davids R, Carr M, Jolly MP, Markl M, Carr JC, Collins JD. The consistency of myocardial strain derived from heart deformation analysis. Int J Cardiovasc Imaging 2017; 33:1169-1177. [DOI: 10.1007/s10554-017-1090-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 02/02/2017] [Indexed: 11/24/2022]
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Varga-Szemes A, van der Geest RJ, Schoepf UJ, Spottiswoode BS, De Cecco CN, Muscogiuri G, Wichmann JL, Mangold S, Fuller SR, Maurovich-Horvat P, Merkely B, Litwin SE, Vliegenthart R, Suranyi P. Effect of inversion time on the precision of myocardial late gadolinium enhancement quantification evaluated with synthetic inversion recovery MR imaging. Eur Radiol 2017; 27:3235-3243. [PMID: 28050692 DOI: 10.1007/s00330-016-4665-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 04/13/2016] [Revised: 08/24/2016] [Accepted: 11/17/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To evaluate the influence of inversion time (TI) on the precision of myocardial late gadolinium enhancement (LGE) quantification using synthetic inversion recovery (IR) imaging in patients with myocardial infarction (MI). METHODS Fifty-three patients with suspected prior MI underwent 1.5-T cardiac MRI with conventional magnitude (MagIR) and phase-sensitive IR (PSIR) LGE imaging and T1 mapping at 15 min post-contrast. T1-based synthetic MagIR and PSIR images were calculated with a TI ranging from -100 to +150 ms at 5-ms intervals relative to the optimal TI (TI0). LGE was quantified using a five standard deviation (5SD) and full width at half-maximum (FWHM) thresholds. Measurements were compared using one-way analysis of variance. RESULTS The MagIRsy technique provided precise assessment of LGE area at TIs ≥ TI0, while precision was decreased below TI0. The LGE area showed significant differences at ≤ -25 ms compared to TI0 using 5SD (P < 0.001) and at ≤ -65 ms using the FWHM approach (P < 0.001). LGE measurements did not show significant difference over the analysed TI range in the PSIRsy images using either of the quantification methods. CONCLUSIONS T1 map-based PSIRsy images provide precise quantification of MI independent of TI at the investigated time point post-contrast. MagIRsy-based MI quantification is precise at TI0 and at longer TIs while showing decreased precision at TI values below TI0. KEY POINTS • Synthetic IR imaging retrospectively generates LGE images at any theoretical TI • Synthetic IR imaging can simulate the effect of TI on LGE quantification • Fifteen minutes post-contrast MagIR sy accurately quantifies infarcts from TI 0 to TI 0 + 150 ms • Fifteen minutes post-contrast PSIR sy provides precise infarct size independent of TI • Synthetic IR imaging has further advantages in reducing operator dependence.
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Affiliation(s)
- Akos Varga-Szemes
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
| | - Rob J van der Geest
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - U Joseph Schoepf
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA.
| | | | - Carlo N De Cecco
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
| | - Giuseppe Muscogiuri
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
- Department of Imaging, Bambino Gesu Children's Hospital IRCCS, Rome, Italy
| | - Julian L Wichmann
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
- Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany
| | - Stefanie Mangold
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
- Department of Diagnostic and Interventional Radiology, Eberhard-Karls University Tuebingen, Tuebingen, Germany
| | - Stephen R Fuller
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
| | - Pal Maurovich-Horvat
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Bela Merkely
- MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, Budapest, Hungary
| | - Sheldon E Litwin
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Rozemarijn Vliegenthart
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
- Center for Medical Imaging-North East Netherlands, Department of Radiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Pal Suranyi
- Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260, USA
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Vassiliou V, Anita S, Malley T, Raphael CE, Tayal U, Ali A, Sehmi J, Bilal H, Mathew GL, Smith GC, Symmonds K, Greiser A, Spottiswoode BS, Alpendurada F, Auger D, Pennell DJ, Gatehouse P, Prasad S. Systolic T1 mapping for estimation of myocardial diffuse fibrosis. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032320 DOI: 10.1186/1532-429x-18-s1-q52] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Vassiliou V, Wassilew K, Asimakopoulos G, Souza AD, Quarto C, Heng EL, Raphael CE, Spottiswoode BS, Greiser A, Nyktari E, Alpendurada F, Firmin D, Jabbour A, Pepper J, Pennell DJ, Gatehouse P, Prasad S. Histological validation of a new CMR T1-mapping-based protocol to improve accuracy for fibrosis assessment in patients with aortic stenosis. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032424 DOI: 10.1186/1532-429x-18-s1-q56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Keller EJ, Smith PM, Freed B, Allen BD, Spottiswoode BS, Carr ML, Jolly MP, Lin K, Carr JC, Collins JD. Comparison of derived strain values of myocardial regions, levels, and segments by field strength and temporal resolution via cine bSSFP MR imaging. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032394 DOI: 10.1186/1532-429x-18-s1-q16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Lin L, Wang Y, Cao J, Kong L, An J, Zhang T, Spottiswoode BS. 3.0T Cardiac Magnetic Resonance Quantification of Myocardial Extracellular Volume using different delay time of post-contrast T1 mapping for the Diagnosis of Cardiac Amyloidosis. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032604 DOI: 10.1186/1532-429x-18-s1-p316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Alam MH, He T, Auger D, Smith GC, Drivas P, Wage R, Izgi C, Symmonds K, Greiser A, Spottiswoode BS, Anderson L, Firmin D, Pennell DJ. Validation of T2* in-line analysis for tissue iron quantification at 1.5 T. J Cardiovasc Magn Reson 2016; 18:23. [PMID: 27121114 PMCID: PMC4847205 DOI: 10.1186/s12968-016-0243-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [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: 12/22/2015] [Accepted: 04/20/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is a need for improved worldwide access to tissue iron quantification using T2* cardiovascular magnetic resonance (CMR). One route to facilitate this would be simple in-line T2* analysis widely available on MR scanners. We therefore compared our clinically validated and established T2* method at Royal Brompton Hospital (RBH T2*) against a novel work-in-progress (WIP) sequence with in-line T2* measurement from Siemens (WIP T2*). METHODS Healthy volunteers (n = 22) and patients with iron overload (n = 78) were recruited (53 males, median age 34 years). A 1.5 T study (Magnetom Avanto, Siemens) was performed on all subjects. The same mid-ventricular short axis cardiac slice and transaxial slice through the liver were used to acquire both RBH T2* images and WIP T2* maps for each participant. Cardiac white blood (WB) and black blood (BB) sequences were acquired. Intraobserver, interobserver and interstudy reproducibility were measured on the same data from a subset of 20 participants. RESULTS Liver T2* values ranged from 0.8 to 35.7 ms (median 5.1 ms) and cardiac T2* values from 6.0 to 52.3 ms (median 31 ms). The coefficient of variance (CoV) values for direct comparison of T2* values by RBH and WIP were 6.1-7.8 % across techniques. Accurate delineation of the septum was difficult on some WIP T2* maps due to artefacts. The inability to manually correct for noise by truncation of erroneous later echo times led to some overestimation of T2* using WIP T2* compared with the RBH T2*. Reproducibility CoV results for RBH T2* ranged from 1.5 to 5.7 % which were better than the reproducibility of WIP T2* values of 4.1-16.6 %. CONCLUSIONS Iron estimation using the T2* CMR sequence in combination with Siemens' in-line data processing is generally satisfactory and may help facilitate global access to tissue iron assessment. The current automated T2* map technique is less good for tissue iron assessment with noisy data at low T2* values.
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Affiliation(s)
- Mohammed H Alam
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Taigang He
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, UK
- Cardiovascular Science Research Center, St George's, University of London, London, UK
| | - Dominique Auger
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Gillian C Smith
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Peter Drivas
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | - Rick Wage
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | - Cemil Izgi
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | - Karen Symmonds
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | | | | | - Lisa Anderson
- Cardiovascular Science Research Center, St George's, University of London, London, UK
| | - David Firmin
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Dudley J Pennell
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK.
- National Heart and Lung Institute, Imperial College, London, UK.
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Vassiliou V, Wassilew K, Malley T, Raphael CE, Schofield RS, Kirby K, Bowman AD, Symmonds K, Spottiswoode BS, Greiser A, Pierce I, Firmin D, Gatehouse P, Pennell DJ, Prasad S. Incremental benefit in correlation with histology of native T1 mapping, partition coefficient and extracellular volume fraction in patients with aortic stenosis. Journal of Cardiovascular Magnetic Resonance 2016. [PMCID: PMC5032579 DOI: 10.1186/1532-429x-18-s1-o48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chatterjee N, Bane O, Spottiswoode BS, Carr JC, Carroll T. Measurement of myocardial blood volume and water exchange using ferumoxytol. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328585 DOI: 10.1186/1532-429x-17-s1-p253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Chatterjee N, Bane O, Spottiswoode BS, Carr JC, Carroll T. Measurement of myocardial blood volume and water exchange using ferumoxytol. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328902 DOI: 10.1186/1532-429x-17-s1-w11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Kali A, Choi EY, Sharif B, Kim YJ, Bi X, Spottiswoode BS, Cokic I, Yang HJ, Tighiouart M, Li D, Berman DS, Choi BW, Chang HJ, Dharmakumar R. Visual detection and characterization of chronic myocardial infarctions in patients using native T1 maps at 3T. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328608 DOI: 10.1186/1532-429x-17-s1-o74] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Piechnik SK, Ferreira VM, Greiser A, Spottiswoode BS, Robson MD, Neubauer S. Inversion time calculations have varying impact on short, intermediate and long MOLLI T1 values: implications for studies using T1-mapping sequences. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328218 DOI: 10.1186/1532-429x-17-s1-p23] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Varga-Szemes A, van der Geest RJ, Spottiswoode BS, Muscogiuri G, De Cecco CN, Suranyi P, Rehwald WG, Schoepf JU. Quantification of myocardial late gadolinium enhancement using synthetic inversion recovery imaging. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328996 DOI: 10.1186/1532-429x-17-s1-o8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Collins JD, Botelho M, Stark M, Lee DC, Kalisz K, Smith PM, Allen BD, Carr ML, Spottiswoode BS, Carr JC, Freed BH. Cardiac MR feature tracking identifies abnormal biventricular global strain values in biopsy-proven non-ischemic cardiomyopathies. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328348 DOI: 10.1186/1532-429x-17-s1-q8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Chow K, Kellman P, Spottiswoode BS, Nielles-Vallespin S, Arai AE, Salerno M, Thompson RB. Saturation pulse design for quantitative myocardial T1 mapping. J Cardiovasc Magn Reson 2015; 17:84. [PMID: 26428468 PMCID: PMC4589956 DOI: 10.1186/s12968-015-0187-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [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: 05/21/2015] [Accepted: 09/02/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Quantitative saturation-recovery based T1 mapping sequences are less sensitive to systematic errors than the Modified Look-Locker Inversion recovery (MOLLI) technique but require high performance saturation pulses. We propose to optimize adiabatic and pulse train saturation pulses for quantitative T1 mapping to have <1 % absolute residual longitudinal magnetization (|MZ/M0|) over ranges of B0 and [Formula: see text] (B1 scale factor) inhomogeneity found at 1.5 T and 3 T. METHODS Design parameters for an adiabatic BIR4-90 pulse were optimized for improved performance within 1.5 T B0 (±120 Hz) and [Formula: see text] (0.7-1.0) ranges. Flip angles in hard pulse trains of 3-6 pulses were optimized for 1.5 T and 3 T, with consideration of T1 values, field inhomogeneities (B0 = ±240 Hz and [Formula: see text]=0.4-1.2 at 3 T), and maximum achievable B1 field strength. Residual MZ/M0 was simulated and measured experimentally for current standard and optimized saturation pulses in phantoms and in-vivo human studies. T1 maps were acquired at 3 T in human subjects and a swine using a SAturation recovery single-SHot Acquisition (SASHA) technique with a standard 90°-90°-90° and an optimized 6-pulse train. RESULTS Measured residual MZ/M0 in phantoms had excellent agreement with simulations over a wide range of B0 and [Formula: see text]. The optimized BIR4-90 reduced the maximum residual |MZ/M0| to <1 %, a 5.8× reduction compared to a reference BIR4-90. An optimized 3-pulse train achieved a maximum residual |MZ/M0| <1 % for the 1.5 T optimization range compared to 11.3 % for a standard 90°-90°-90° pulse train, while a 6-pulse train met this target for the wider 3 T ranges of B0 and [Formula: see text]. The 6-pulse train demonstrated more uniform saturation across both the myocardium and entire field of view than other saturation pulses in human studies. T1 maps were more spatially homogeneous with 6-pulse train SASHA than the reference 90°-90°-90° SASHA in both human and animal studies. CONCLUSIONS Adiabatic and pulse train saturation pulses optimized for different constraints found at 1.5 T and 3 T achieved <1 % residual |MZ/M0| in phantom experiments, enabling greater accuracy in quantitative saturation recovery T1 imaging.
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Affiliation(s)
- Kelvin Chow
- Department of Biomedical Engineering, Faculty of Medicine and Dentistry, 1082 Research Transition Facility, University of Alberta, Edmonton, AB, T6G 2V2, Canada.
| | - Peter Kellman
- National Institutes of Health, Department of Health and Human Services, National Heart, Lung and Blood Institute, Bethesda, MD, USA.
| | | | - Sonia Nielles-Vallespin
- National Institutes of Health, Department of Health and Human Services, National Heart, Lung and Blood Institute, Bethesda, MD, USA.
| | - Andrew E Arai
- National Institutes of Health, Department of Health and Human Services, National Heart, Lung and Blood Institute, Bethesda, MD, USA.
| | - Michael Salerno
- Cardiovascular Division, Departments of Medicine, Radiology and Medical Imaging, University of Virginia Health System, Charlottesville, VA, USA.
- Biomedical Engineering, University of Virginia Health System, Charlottesville, VA, USA.
| | - Richard B Thompson
- Department of Biomedical Engineering, Faculty of Medicine and Dentistry, 1082 Research Transition Facility, University of Alberta, Edmonton, AB, T6G 2V2, Canada.
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Varga-Szemes A, Muscogiuri G, Schoepf UJ, De Cecco CN, Wichmann JL, Mangold S, Caruso D, Fuller SR, Spottiswoode BS, van der Geest RJ, Suranyi P. Overview of Myocardial T1 Mapping Applications. Curr Radiol Rep 2015. [DOI: 10.1007/s40134-015-0114-z] [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: 11/24/2022]
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Varga-Szemes A, van der Geest RJ, Spottiswoode BS, Suranyi P, Ruzsics B, De Cecco CN, Muscogiuri G, Cannaò PM, Fox MA, Wichmann JL, Vliegenthart R, Schoepf UJ. Myocardial Late Gadolinium Enhancement: Accuracy of T1 Mapping-based Synthetic Inversion-Recovery Imaging. Radiology 2015; 278:374-82. [PMID: 26230908 DOI: 10.1148/radiol.2015150162] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE To compare the accuracy of detection and quantification of myocardial late gadolinium enhancement (LGE) with a synthetic inversion-recovery (IR) approach with that of conventional IR techniques. MATERIALS AND METHODS This prospective study was approved by the institutional review board and compliant with HIPAA. All patients gave written informed consent. Between June and November 2014, 43 patients (25 men; mean age, 54 years ± 16) suspected of having previous myocardial infarction underwent magnetic resonance (MR) imaging, including contrast material-enhanced LGE imaging and T1 mapping. Synthetic magnitude and phase-sensitive IR images were generated on the basis of T1 maps. Images were assessed by two readers. Differences in the per-patient and per-segment LGE detection rates between the synthetic and conventional techniques were analyzed with the McNemar test, and the accuracy of LGE quantification was calculated with the paired t test and Bland-Altman statistics. Interreader agreement for the detection and quantification of LGE was analyzed with κ and Bland-Altman statistics, respectively. RESULTS Seventeen of the 43 patients (39%) had LGE patterns consistent with myocardial infarction. The sensitivity and specificity of synthetic magnitude and phase-sensitive IR techniques in the detection of LGE were 90% and 95%, respectively, with patient-based analysis and 94% and 99%, respectively, with segment-based analysis. The area of LGE measured with synthetic IR techniques showed excellent agreement with that of conventional techniques (4.35 cm(2) ± 1.88 and 4.14 cm(2)± 1.62 for synthetic magnitude and phase-sensitive IR, respectively, compared with 4.25 cm(2) ± 1.92 and 4.22 cm(2) ± 1.86 for conventional magnitude and phase-sensitive IR, respectively; P > .05). Interreader agreement was excellent for the detection (κ > 0.81) and quantification (bias range, -0.34 to 0.40; P > .05) of LGE. CONCLUSION The accuracy of the T1 map-based synthetic IR approach in the detection and quantification of myocardial LGE in patients with previous myocardial infarction was similar to that of conventional IR techniques. The use of T1 mapping to derive synthetic LGE images may reduce imaging times and operator dependence in future T1 mapping protocols with full left ventricular coverage.
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Affiliation(s)
- Akos Varga-Szemes
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Rob J van der Geest
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Bruce S Spottiswoode
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Pal Suranyi
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Balazs Ruzsics
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Carlo N De Cecco
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Giuseppe Muscogiuri
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Paola M Cannaò
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Mary A Fox
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Julian L Wichmann
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - Rozemarijn Vliegenthart
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
| | - U Joseph Schoepf
- From the Division of Cardiovascular Imaging, Department of Radiology and Radiological Science (A.V.S., P.S., C.N.D.C., G.M., P.M.C., M.A.F., J.L.W., R.V., U.J.S.), and Division of Cardiology, Department of Medicine (U.J.S.), Medical University of South Carolina, Ashley River Tower, 25 Courtenay Dr, Charleston, SC 29245-2260; Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands (R.J.v.d.G.); Siemens Medical Solutions, Chicago, Ill (B.S.S.); and Department of Cardiology, Royal Liverpool and Broadgreen University Hospitals, Liverpool, United Kingdom (B.R.)
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Fan J, Meintjes EM, Molteno CD, Spottiswoode BS, Dodge NC, Alhamud AA, Stanton ME, Peterson BS, Jacobson JL, Jacobson SW. White matter integrity of the cerebellar peduncles as a mediator of effects of prenatal alcohol exposure on eyeblink conditioning. Hum Brain Mapp 2015; 36:2470-82. [PMID: 25783559 DOI: 10.1002/hbm.22785] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [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: 09/17/2014] [Revised: 02/23/2015] [Accepted: 02/25/2015] [Indexed: 11/06/2022] Open
Abstract
Fetal alcohol spectrum disorders (FASD) are characterized by a range of neurodevelopmental deficits that result from prenatal exposure to alcohol. These can include cognitive, behavioural, and neurological impairment, as well as structural and functional brain damage. Eyeblink conditioning (EBC) is among the most sensitive endpoints affected in FASD. The cerebellar peduncles, large bundles of myelinated nerve fibers that connect the cerebellum to the brainstem, constitute the principal white matter element of the EBC circuit. Diffusion tensor imaging (DTI) is used to assess white matter integrity in fibre pathways linking brain regions. DTI scans of 54 children with FASD and 23 healthy controls, mean age 10.1 ± 1.0 years, from the Cape Town Longitudinal Cohort were processed using voxelwise group comparisons. Prenatal alcohol exposure was related to lower fractional anisotropy (FA) bilaterally in the superior cerebellar peduncles and higher mean diffusivity (MD) in the left middle peduncle, effects that remained significant after controlling for potential confounding variables. Lower FA and higher MD in these regions were associated with poorer EBC performance. Moreover, effects of alcohol exposure on EBC decreased significantly after inclusion of these DTI measures in regression models, suggesting that these white matter deficits partially mediate the relation of prenatal alcohol exposure to EBC. The associations of greater alcohol consumption with these DTI measures are largely attributable to greater radial diffusivity, possibly indicating poorer myelination. Thus, these data suggest that fetal alcohol-related deficits in EBC are attributable, in part, to poorer myelination in key regions of the cerebellar peduncles.
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Affiliation(s)
- Jia Fan
- MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa.,Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Ernesta M Meintjes
- MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa.,Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Christopher D Molteno
- Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | | | - Neil C Dodge
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Alkathafi A Alhamud
- MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa.,Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Mark E Stanton
- Department of Psychology, University of Delaware, Delaware, Maryland
| | - Bradley S Peterson
- Institute for the Developing Mind, Children's Hospital Los Angeles and the Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Joseph L Jacobson
- Department of Human Biology, University of Cape Town, Cape Town, South Africa.,Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa.,Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Sandra W Jacobson
- Department of Human Biology, University of Cape Town, Cape Town, South Africa.,Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa.,Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan
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Rao AK, Greve AM, Nielles-Vallespin S, Spottiswoode BS, Chow K, Thompson RB, Kellman P, Arai AE. Variability of T1 in purpose recruited normal volunteers and patients as a function of shim (B0), flip angle (B1) and myocardial sector at 3T. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328414 DOI: 10.1186/1532-429x-17-s1-p5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Kellman P, Xue H, Spottiswoode BS, Sandino CM, Hansen MS, Abdel-Gadir A, Treibel TA, Rosmini S, Mancini C, Bandettini WP, McGill LA, Gatehouse P, Moon JC, Pennell DJ, Arai AE. Free-breathing T2* mapping using respiratory motion corrected averaging. J Cardiovasc Magn Reson 2015; 17:3. [PMID: 25616857 PMCID: PMC4305251 DOI: 10.1186/s12968-014-0106-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [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: 06/26/2014] [Accepted: 12/29/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pixel-wise T2* maps based on breath-held segmented image acquisition are prone to ghost artifacts in instances of poor breath-holding or cardiac arrhythmia. Single shot imaging is inherently immune to ghost type artifacts. We propose a free-breathing method based on respiratory motion corrected single shot imaging with averaging to improve the signal to noise ratio. METHODS Images were acquired using a multi-echo gradient recalled echo sequence and T2* maps were calculated at each pixel by exponential fitting. For 40 subjects (2 cohorts), two acquisition protocols were compared: (1) a breath-held, segmented acquisition, and (2) a free-breathing, single-shot multiple repetition respiratory motion corrected average. T2* measurements in the interventricular septum and liver were compared for the 2-methods in all studies with diagnostic image quality. RESULTS In cohort 1 (N = 28) with age 51.4 ± 17.6 (m ± SD) including 1 subject with severe myocardial iron overload, there were 8 non-diagnostic breath-held studies due to poor image quality resulting from ghost artifacts caused by respiratory motion or arrhythmias. In cohort 2 (N = 12) with age 30.9 ± 7.5 (m ± SD), including 7 subjects with severe myocardial iron overload and 4 subjects with mild iron overload, a single subject was unable to breath-hold. Free-breathing motion corrected T2* maps were of diagnostic quality in all 40 subjects. T2* measurements were in excellent agreement (In cohort #1, T2*FB = 0.95 x T2*BH + 0.41, r2 = 0.93, N = 39 measurements, and in cohort #2, T2*FB = 0.98 x T2*BH + 0.05, r2 > 0.99, N = 22 measurements). CONCLUSIONS A free-breathing approach to T2* mapping is demonstrated to produce consistently good quality maps in the presence of respiratory motion and arrhythmias.
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Affiliation(s)
- Peter Kellman
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - Hui Xue
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | | | - Christopher M Sandino
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - Michael S Hansen
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - Amna Abdel-Gadir
- />The Heart Hospital, 16-18 Westmoreland Street, London, W1G 8PH UK
| | - Thomas A Treibel
- />The Heart Hospital, 16-18 Westmoreland Street, London, W1G 8PH UK
| | - Stefania Rosmini
- />The Heart Hospital, 16-18 Westmoreland Street, London, W1G 8PH UK
| | - Christine Mancini
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - W Patricia Bandettini
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - Laura-Ann McGill
- />Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - Peter Gatehouse
- />Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - James C Moon
- />The Heart Hospital, 16-18 Westmoreland Street, London, W1G 8PH UK
| | - Dudley J Pennell
- />Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - Andrew E Arai
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
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Kellman P, Xue H, Chow K, Spottiswoode BS, Arai AE, Thompson RB. Optimized saturation recovery protocols for T1-mapping in the heart: influence of sampling strategies on precision. J Cardiovasc Magn Reson 2014; 16:55. [PMID: 25190004 PMCID: PMC4244052 DOI: 10.1186/s12968-014-0055-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [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: 05/07/2014] [Accepted: 07/09/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND T1-mapping has the potential to detect and quantify diffuse processes such as interstitial fibrosis. Detection of disease at an early stage by measurement of subtle changes requires a high degree of reproducibility. Initial implementation of saturation recovery (SR) T1-mapping employed 3-parameter fitting which was highly accurate but was quite sensitive to noise; 2-parameter fitting greatly reduced the sensitivity to noise at the expense of a small degree of systematic bias. A recently introduced implementation that uses a variable readout flip angle greatly reduces systematic errors in T1-measurement thereby making it feasible to use SR methods with 2-parameter fitting with improved accuracy and precision. SR T1 mapping techniques with multi-heartbeat recovery times have been proposed to better sample the T1 recovery curve, but have not been evaluated for 2-parameter fitting. METHODS An analytic formulation for calculating the standard deviation (SD) for SR T1-mapping with 2-parameter fitting is developed and validated using Monte-Carlo simulation. The coefficient of variation is compared for a brute force optimization of sampling and for several previously described sampling schemes for T1 measurement over several uncertainty ranges. Experimental validation is performed in phantoms over a range of T1, and in-vivo both native and post-contrast. Pixel-wise SD maps are calculated for SR T1-mapping. RESULTS Sampling schemes that use a non-saturated anchor image and multiple (N) measurements at a single fixed saturation delay are found to be near optimum for the case of known T1 and are close to the brute force optimized solution over wide ranges of native and post-contrast T1 values. The fixed delay sampling scheme is simple to implement and provides an improvement over uniformly distributed schemes. CONCLUSIONS Sampling strategies for saturation recovery methods for myocardial T1-mapping have been optimized and validated experimentally. Reduced SD, or improved precision, may be achieved by using fixed saturation delays when considering native myocardium and post-contrast T1 ranges. Pixel-wise estimates of T1 mapping errors have been formulated and validated for SR fitting methods.
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Affiliation(s)
- Peter Kellman
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - Hui Xue
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - Kelvin Chow
- />Department of Biomedical Engineering, University of Alberta, Edmonton, Canada
| | | | - Andrew E Arai
- />National Heart, Lung, and Blood Institute, National Institutes of Health, DHHS, 10 Center Drive MSC-1061, Bethesda, MD 20892 USA
| | - Richard B Thompson
- />Department of Biomedical Engineering, University of Alberta, Edmonton, Canada
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Parekh K, Rigsby CK, deFreitas RA, Spottiswoode BS, Markl M. Quantitative non-contrast T1 mapping of left ventricle in children and young adults. J Cardiovasc Magn Reson 2014. [PMCID: PMC4045832 DOI: 10.1186/1532-429x-16-s1-p268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
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Shao J, Natsuaki Y, Spottiswoode BS, Hu P. Instantaneous Signal Loss simulation (InSiL) - an alternative algorithm for myocardial T1 mapping using the MOLLI sequence. J Cardiovasc Magn Reson 2014. [PMCID: PMC4043513 DOI: 10.1186/1532-429x-16-s1-p26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jiaxin Shao
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | | | | | - Peng Hu
- Department of Radiological Sciences, David Geffen School of Medicine, University of California, Los Angeles, California, USA,Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, California, USA
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Smith PM, Daruwalla V, Freed BH, Spottiswoode BS, Kalisz K, Carr JC, Collins JD. Myocardial strain analysis in patients with Heart Failure with preserved Ejection Fraction using bright blood cine MR images: A comparison with speckle-tracking echocardiography. J Cardiovasc Magn Reson 2014. [PMCID: PMC4042354 DOI: 10.1186/1532-429x-16-s1-p71] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Auger DA, Zhong X, Epstein FH, Meintjes EM, Spottiswoode BS. Semi-automated left ventricular segmentation based on a guide point model approach for 3D cine DENSE cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2014; 16:8. [PMID: 24423129 PMCID: PMC3903450 DOI: 10.1186/1532-429x-16-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 12/03/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The most time consuming and limiting step in three dimensional (3D) cine displacement encoding with stimulated echoes (DENSE) MR image analysis is the demarcation of the left ventricle (LV) from its surrounding anatomical structures. The aim of this study is to implement a semi-automated segmentation algorithm for 3D cine DENSE CMR using a guide point model approach. METHODS A 3D mathematical model is fitted to guide points which were interactively placed along the LV borders at a single time frame. An algorithm is presented to robustly propagate LV epicardial and endocardial surfaces of the model using the displacement information encoded in the phase images of DENSE data. The accuracy, precision and efficiency of the algorithm are tested. RESULTS The model-defined contours show good accuracy when compared to the corresponding manually defined contours as similarity coefficients Dice and Jaccard consist of values above 0.7, while false positive and false negative measures show low percentage values. This is based on a measure of segmentation error on intra- and inter-observer spatial overlap variability. The segmentation algorithm offers a 10-fold reduction in the time required to identify LV epicardial and endocardial borders for a single 3D DENSE data set. CONCLUSION A semi-automated segmentation method has been developed for 3D cine DENSE CMR. The algorithm allows for contouring of the first cardiac frame where blood-myocardium contrast is almost nonexistent and reduces the time required to segment a 3D DENSE data set significantly.
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Affiliation(s)
- Daniel A Auger
- MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Xiaodong Zhong
- MR R&D Collaborations, Siemens Medical Solutions, Atlanta, GA, USA
| | - Frederick H Epstein
- Departments of Radiology and Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Ernesta M Meintjes
- MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa
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Allen BD, Carr M, Zenge MO, Schmidt M, Nadar MS, Spottiswoode BS, Collins JD, Carr JC. Clinical evaluation of accelerated cardiac cine imaging using iterative k-t-sparse SENSE. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044287 DOI: 10.1186/1532-429x-16-s1-w13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Smith PM, Freed BH, Allen BD, Spottiswoode BS, Carr M, Wasielewski M, Campione K, Schmidt M, Nadar MS, Zenge MO, Carr JC, Collins JD. Biventricular strain analysis at 1.5T cardiac MR imaging: preliminary results in volunteers using an iterative SENSE reconstruction with L1 regularization. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044769 DOI: 10.1186/1532-429x-16-s1-p62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Ferreira P, Kilner PJ, McGill LA, Nielles-Vallespin S, Scott AD, Spottiswoode BS, Zhong X, Ho SY, McCarthy K, Ismail T, Gatehouse P, Silva R, Lyon A, Prasad SK, Firmin D, Pennell DJ. Aberrant myocardial sheetlet mobility in hypertrophic cardiomyopathy detected using in vivo cardiovascular magnetic resonance diffusion tensor imaging. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044463 DOI: 10.1186/1532-429x-16-s1-p338] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Allen BD, Carr M, Zenge MO, Schmidt M, Nadar MS, Spottiswoode BS, Collins JD, Carr JC. Evaluation of accelerated real-time CMR using sparse sampling with iterative SENSE reconstruction in patients and volunteers. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044417 DOI: 10.1186/1532-429x-16-s1-o12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Flanagan O, Spottiswoode BS, Carr M, Collins JD, Bi X, Botelho M, Ayache JB, Edelman RR, Carr JC. The validity of a free breathing motion corrected phase sensitive inversion recovery sequence in the detection of delayed myocardial enhancement in non-ischemic heart disease. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044998 DOI: 10.1186/1532-429x-16-s1-p305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Smith PM, Freed BH, Allen BD, Spottiswoode BS, Carr M, Wasielewski M, Campione K, Cordts M, Guetter C, Jolly MP, Schmidt M, Nadar MS, Zenge MO, Carr JC, Collins JD. Biventricular strain analysis at 1.5T cardiac MR imaging: preliminary results in volunteers using an iterative SENSE reconstruction with L1 regularization. J Cardiovasc Magn Reson 2014. [PMCID: PMC4045056 DOI: 10.1186/1532-429x-16-s1-w4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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38
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Alam MH, Baksi AJ, He T, Smith GC, Izgi C, Wage R, Drivas P, Greiser A, Spottiswoode BS, Firmin D, Pennell DJ. Validation of Siemens T2* inline WIP package for quantification of cardiac and hepatic iron loading at 1.5T and 3T. J Cardiovasc Magn Reson 2014. [PMCID: PMC4043195 DOI: 10.1186/1532-429x-16-s1-p323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Semaan E, Spottiswoode BS, Freed B, Stankovic Z, Allen BD, Carr M, Wasielewski M, Campione K, Shah S, Carr JC, Markl M, Collins JD. High-resolution modified look-locker inversion recovery (HR-MOLLI) for RV extracellular volume fraction at 3T and 1.5T: A feasibility study. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044445 DOI: 10.1186/1532-429x-16-s1-p159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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40
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Collins JD, Sommerville L, Föll D, Magrath P, Spottiswoode BS, Freed BH, Carr JC, Markl M. Regional left ventricular myocardial T1 and velocity mapping: elevated extracellular volume fraction is associated with altered myocardial velocities. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044316 DOI: 10.1186/1532-429x-16-s1-p5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Sirry MS, Davies NH, Kadner K, Dubuis L, Saleh MG, Meintjes EM, Spottiswoode BS, Zilla P, Franz T. Micro-structurally detailed model of a therapeutic hydrogel injectate in a rat biventricular cardiac geometry for computational simulations. Comput Methods Biomech Biomed Engin 2013; 18:325-31. [PMID: 23682845 DOI: 10.1080/10255842.2013.793765] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [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: 01/26/2023]
Abstract
Biomaterial injection-based therapies have showed cautious success in restoration of cardiac function and prevention of adverse remodelling into heart failure after myocardial infarction (MI). However, the underlying mechanisms are not well understood. Computational studies utilised simplified representations of the therapeutic myocardial injectates. Wistar rats underwent experimental infarction followed by immediate injection of polyethylene glycol hydrogel in the infarct region. Hearts were explanted, cryo-sectioned and the region with the injectate histologically analysed. Histological micrographs were used to reconstruct the dispersed hydrogel injectate. Cardiac magnetic resonance imaging data from a healthy rat were used to obtain an end-diastolic biventricular geometry which was subsequently adjusted and combined with the injectate model. The computational geometry of the injectate exhibited microscopic structural details found the in situ. The combination of injectate and cardiac geometry provides realistic geometries for multiscale computational studies of intra-myocardial injectate therapies for the rat model that has been widely used for MI research.
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Affiliation(s)
- Mazin S Sirry
- a Cardiovascular Research Unit, Chris Barnard Division of Cardiothoracic Surgery, Faculty of Health Sciences, University of Cape Town , Private Bag X3, 7935 Observatory , South Africa
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Spottiswoode BS, van den Heever DJ, Chang Y, Engelhardt S, Du Plessis S, Nicolls F, Hartzenberg HB, Gretschel A. Preoperative three-dimensional model creation of magnetic resonance brain images as a tool to assist neurosurgical planning. Stereotact Funct Neurosurg 2013; 91:162-9. [PMID: 23446024 DOI: 10.1159/000345264] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 10/15/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Neurosurgeons regularly plan their surgery using magnetic resonance imaging (MRI) images, which may show a clear distinction between the area to be resected and the surrounding healthy brain tissue depending on the nature of the pathology. However, this distinction is often unclear with the naked eye during the surgical intervention, and it may be difficult to infer depth and an accurate volumetric interpretation from a series of MRI image slices. OBJECTIVES In this work, MRI data are used to create affordable patient-specific 3-dimensional (3D) scale models of the brain which clearly indicate the location and extent of a tumour relative to brain surface features and important adjacent structures. METHODS This is achieved using custom software and rapid prototyping. In addition, functionally eloquent areas identified using functional MRI are integrated into the 3D models. RESULTS Preliminary in vivo results are presented for 2 patients. The accuracy of the technique was estimated both theoretically and by printing a geometrical phantom, with mean dimensional errors of less than 0.5 mm observed. CONCLUSIONS This may provide a practical and cost-effective tool which can be used for training, and during neurosurgical planning and intervention.
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Affiliation(s)
- B S Spottiswoode
- MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa
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Ahmed F, Spottiswoode BS, Carey PD, Stein DJ, Seedat S. Relationship between neurocognition and regional brain volumes in traumatized adolescents with and without posttraumatic stress disorder. Neuropsychobiology 2013; 66:174-84. [PMID: 22948482 DOI: 10.1159/000339558] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 05/21/2012] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Studies using convergent neurocognitive and structural imaging paradigms in adolescent posttraumatic stress disorder (PTSD) are limited; in the current study we used both voxel-based morphometry (VBM) to obtain between-group volumetric differences, and Freesurfer to examine the relationship between cognition and regional brain volumes. METHODS Participants were 21 traumatized adolescents with PTSD matched with 32 traumatized adolescents without PTSD. Magnetic resonance images were obtained on a 1.5-Tesla MAGNETOM Siemens Symphony scanner. VBM implemented on FSL was then used to compare between-group grey matter volumes, after which Freesurfer was used to obtain global volume and thickness measurements in different brain regions. RESULTS Significant between-group neurocognitive differences were found for tests of attention, delayed recall and visual reconstruction. On VBM, reduced grey matter was found in three regions in the PTSD group: left insula, right precuneus and right cingulate gyrus, using uncorrected values (p < 0.001), while no statistically significant between-group differences were found on the initial Freesurfer stream. Further Freesurfer analysis on Qdec revealed significant reductions in the insula for the PTSD group. In addition, volumetric changes in the corpus callosum and insula were significantly associated with deficits in logical memory and visual reproduction on Freesurfer analysis. CONCLUSIONS Trauma exposure of itself may be sufficient to cause structural changes in adolescents regardless of PTSD development.
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Affiliation(s)
- Fatima Ahmed
- South African Research Chairs Initiative in Posttraumatic Stress Disorder, Stellenbosch University, Cape Town, South Africa
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Andronikou S, Spottiswoode BS, Tomazos N. A semi-automated method for measuring thickness and white matter integrity of the corpus callosum. SA J Radiol 2012. [DOI: 10.4102/sajr.v16i4.257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Aim. Diseases affecting cerebral white matter may lead to left-right asymmetries and atrophy of interhemispheric connections, i.e. the corpus callosum (CC). Our aim was to describe and test a semi-automated system that divides the midline CC into a number of segments and determines thickness at each, then performs fibre tracking from these segments.
Methods. Six normal female volunteers (average age 25.8 ±6.7 years) and a female patient with diagnosed multiple sclerosis (age 26 years) were scanned on a 3T MRI. We performed diffusion-weighted imaging in 12 directions, and calculated diffusion tensors and fractional anisotropy (FA) maps from this pre-processed data. Fibre tracking from a region-of-interest encompassing the entire CC was done. This fibre data, together with FA maps and the unweighted diffusion tensor imaging (DTI) image (b = 0 s/mm2), were imported into a custom tool written in MATLAB. The midline sagittal position was carefully defined by selecting multiple midline points in coronal and axial views and rotating the image volume and fibre co-ordinates accordingly. Using the customised tool, dorsal and ventral CC contours were manually drawn on the mid-sagittal FA image, initiating automated calculation of a contour midway between these manually drawn lines. The programme was designed to then divide the midline contour into a pre-selected number of segments; from each segment border, perpendicular spokes were projected until they intersected with the dorsal and ventral contours. This technique divided the CC into a pre-set amount of segments, the number of which was limited by the spatial resolution. It was decided to set the number at 40 to ensure that each segment depicted a contiguous strip of voxels across the CC from the dorsal to the ventral contour. The system allows these segments to then be used as seeds for separate fibre tracking in each cerebral hemisphere, and various parameters are automatically plotted as a function of distance along the midline contour. The following parameters are measurable: midline CC thickness; midline FA; fibre volume for each hemisphere (represented as a left/right ratio centred on zero) and mean fibre FA for each hemisphere (also represented as a left/right ratio centred on zero).
Results. The tool proved successful in measuring and plotting CC midline thickness and FA, but was not sensitive for peripheral white matter lesions.
Conclusions. The technique successfully determined values of CC midline thickness, FA and interhemispheric differences. Future research will determine normal values for age and compare CC thickness with peripheral white matter volume loss in large groups of patients, using the semiautomated technique.
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Spottiswoode BS, Du Plessis S, Gretschel A, Lotz JW. Functional MRI in pre-surgical planning: Case study and cautionary notes. SA J Radiol 2012. [DOI: 10.4102/sajr.v16i3.293] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Background. Since its inception almost 20 years ago, functional magnetic resonance imaging (fMRI) has greatly advanced our knowledge of human brain function. Although the clinical applications of fMRI are still limited, there have recently been encouraging advances for its use in pre-operative functional cortical mapping to identify potentially eloquent areas prior to neurosurgery.
Objectives. We explore the potential use of this emerging technique by presenting a neurosurgical case study, as performed at the Cape Universities Brain Imaging Centre (CUBIC), Tygerberg, Cape Town. We conclude with a brief summary of the potential pitfalls of this technique, as well as cautionary guidelines based on our experience.
Methods and results. A 22-year-old male patient from Tygerberg Hospital underwent the successful resection of an anaplastic astrocytoma after fMRI presurgical planning at our facility. The subject was able to leave the ward unassisted.
Conclusion. If consideration is given to the many limitations of this emerging technique, fMRI can be useful in aiding the neurosurgeon in pre-operative planning of his surgical approach.
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Auger DA, Zhong X, Epstein FH, Spottiswoode BS. Mapping right ventricular myocardial mechanics using 3D cine DENSE cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2012; 14:4. [PMID: 22236389 PMCID: PMC3311142 DOI: 10.1186/1532-429x-14-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Accepted: 01/11/2012] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The mechanics of the right ventricle (RV) are not well understood as studies of the RV have been limited. This is, in part, due to the RV's thin wall, asymmetric geometry and irregular motion. However, the RV plays an important role in cardiovascular function. This study aims to describe the complex mechanics of the healthy RV using three dimensional (3D) cine displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance (CMR). METHODS Whole heart 3D cine DENSE data were acquired from five healthy volunteers. Tailored post-processing algorithms for RV mid-wall tissue tracking and strain estimation are presented. A method for sub-dividing the RV into four regions according to anatomical land marks is proposed, and the temporal evolution of strain was assessed in these regions. RESULTS The 3D cine DENSE tissue tracking methods successfully capture the motion and deformation of the RV at a high spatial resolution in all volunteers. The regional Lagrangian peak surface strain and time to peak values correspond with previous studies using myocardial tagging, DENSE and strain encoded CMR. The inflow region consistently displays lower peak strains than the apical and outflow regions, and the time to peak strains suggest RV mechanical activation in the following order: inflow, outflow, mid, then apex. CONCLUSIONS Model-free techniques have been developed to study the myocardial mechanics of the RV at a high spatial resolution using 3D cine DENSE CMR. The consistency of the regional RV strain patterns across healthy subjects is encouraging and the techniques may have clinical utility in assessing disrupted RV mechanics in the diseased heart.
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Affiliation(s)
- Daniel A Auger
- MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Xiaodong Zhong
- MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, USA
| | - Frederick H Epstein
- Departments of Radiology and Biomedical Engineering, University of Virginia, Charlottesville VA, USA
| | - Bruce S Spottiswoode
- MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, South Africa
- Division of Radiology, University of Stellenbosch, Cape Town, South Africa
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Zhong X, Gibberman LB, Spottiswoode BS, Gilliam AD, Meyer CH, French BA, Epstein FH. Comprehensive cardiovascular magnetic resonance of myocardial mechanics in mice using three-dimensional cine DENSE. J Cardiovasc Magn Reson 2011; 13:83. [PMID: 22208954 PMCID: PMC3278394 DOI: 10.1186/1532-429x-13-83] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 12/30/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Quantitative noninvasive imaging of myocardial mechanics in mice enables studies of the roles of individual genes in cardiac function. We sought to develop comprehensive three-dimensional methods for imaging myocardial mechanics in mice. METHODS A 3D cine DENSE pulse sequence was implemented on a 7T small-bore scanner. The sequence used three-point phase cycling for artifact suppression and a stack-of-spirals k-space trajectory for efficient data acquisition. A semi-automatic 2D method was adapted for 3D image segmentation, and automated 3D methods to calculate strain, twist, and torsion were employed. A scan protocol that covered the majority of the left ventricle in a scan time of less than 25 minutes was developed, and seven healthy C57Bl/6 mice were studied. RESULTS Using these methods, multiphase normal and shear strains were measured, as were myocardial twist and torsion. Peak end-systolic values for the normal strains at the mid-ventricular level were 0.29 ± 0.17, -0.13 ± 0.03, and -0.18 ± 0.14 for E(rr), E(cc), and E(ll), respectively. Peak end-systolic values for the shear strains were 0.00 ± 0.08, 0.04 ± 0.12, and 0.03 ± 0.07 for E(rc), E(rl), and E(cl), respectively. The peak end-systolic normalized torsion was 5.6 ± 0.9°. CONCLUSIONS Using a 3D cine DENSE sequence tailored for cardiac imaging in mice at 7 T, a comprehensive assessment of 3D myocardial mechanics can be achieved with a scan time of less than 25 minutes and an image analysis time of approximately 1 hour.
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Affiliation(s)
| | | | - Bruce S Spottiswoode
- MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa
| | | | - Craig H Meyer
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Brent A French
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Frederick H Epstein
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
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Auger DA, Zhong X, Meintjes EM, Epstein FH, Spottiswoode BS. Quantifying right ventricular motion and strain using 3D cine DENSE MRI. J Cardiovasc Magn Reson 2011. [PMCID: PMC3106615 DOI: 10.1186/1532-429x-13-s1-m3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Zhong X, Spottiswoode BS, Meyer CH, Epstein FH. Comparison of SNR efficiencies and strain for cine DENSE using conventional EPI, flyback EPI and spiral k-space trajectories. J Cardiovasc Magn Reson 2011. [PMCID: PMC3106891 DOI: 10.1186/1532-429x-13-s1-p58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Spottiswoode BS, Meintjes EM, Anderson AW, Molteno CD, Stanton ME, Dodge NC, Gore JC, Peterson BS, Jacobson JL, Jacobson SW. Diffusion tensor imaging of the cerebellum and eyeblink conditioning in fetal alcohol spectrum disorder. Alcohol Clin Exp Res 2011; 35:2174-83. [PMID: 21790667 DOI: 10.1111/j.1530-0277.2011.01566.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Prenatal alcohol exposure is related to a wide range of neurocognitive effects. Eyeblink conditioning (EBC), which involves temporal pairing of a conditioned with an unconditioned stimulus, has been shown to be a potential biomarker of fetal alcohol exposure. A growing body of evidence suggests that white matter may be a specific target of alcohol teratogenesis, and the neural circuitry underlying EBC is known to involve the cerebellar peduncles. Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) technique that has proven useful for assessing central nervous system white matter integrity. This study used DTI to examine the degree to which the fetal alcohol-related deficit in EBC may be mediated by structural impairment in the cerebellar peduncles. METHODS Thirteen children with fetal alcohol spectrum disorder (FASD) and 12 matched controls were scanned using DTI and structural MRI sequences. The DTI data were processed using a voxelwise technique, and the structural data were used for volumetric analyses. Prenatal alcohol exposure group and EBC performance were examined in relation to brain volumes and outputs from the DTI analysis. RESULTS Fractional anisotropy (FA) and perpendicular diffusivity group differences between alcohol-exposed and nonexposed children were identified in the left middle cerebellar peduncle. Alcohol exposure correlated with lower FA and greater perpendicular diffusivity in this region, and these correlations remained significant even after controlling for total brain and cerebellar volumes. Conversely, trace conditioning performance was related to higher FA and lower perpendicular diffusivity in the left middle peduncle. The effect of prenatal alcohol exposure on trace conditioning was partially mediated by lower FA in this region. CONCLUSIONS This study extends recent findings that have used DTI to reveal microstructural deficits in white matter in children with FASD. This is the first DTI study to demonstrate mediation of a fetal alcohol-related effect on neuropsychological function by deficits in white matter integrity.
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Affiliation(s)
- Bruce S Spottiswoode
- Department of Human Biology, University of Cape Town Faculty of Health Sciences, South Africa. bspotty@gmail
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