1
|
Pan Y, Varghese J, Tong MS, Yildiz VO, Azzu A, Gatehouse P, Wage R, Nielles-Vallespin S, Pennell DJ, Jin N, Bacher M, Hayes C, Speier P, Simonetti OP. Two-center validation of Pilot Tone based cardiac triggering of a comprehensive cardiovascular magnetic resonance examination. Int J Cardiovasc Imaging 2024; 40:261-273. [PMID: 38082073 DOI: 10.1007/s10554-023-03002-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/31/2023] [Indexed: 12/26/2023]
Abstract
The electrocardiogram (ECG) signal is prone to distortions from gradient and radiofrequency interference and the magnetohydrodynamic effect during cardiovascular magnetic resonance imaging (CMR). Although Pilot Tone Cardiac (PTC) triggering has the potential to overcome these limitations, effectiveness across various CMR techniques has yet to be established. To evaluate the performance of PTC triggering in a comprehensive CMR exam. Fifteen volunteers and 20 patients were recruited at two centers. ECG triggered images were collected for comparison in a subset of sequences. The PTC trigger accuracy was evaluated against ECG in cine acquisitions. Two experienced readers scored image quality in PTC-triggered cine, late gadolinium enhancement (LGE), and T1- and T2-weighted dark-blood turbo spin echo (DB-TSE) images. Quantitative cardiac function, flow, and parametric mapping values obtained using PTC and ECG triggered sequences were compared. Breath-held segmented cine used for trigger timing analysis was collected in 15 volunteers and 14 patients. PTC calibration failed in three volunteers and one patient; ECG trigger recording failed in one patient. Out of 1987 total heartbeats, three mismatched trigger PTC-ECG pairs were found. Image quality scores showed no significant difference between PTC and ECG triggering. There was no significant difference found in quantitative measurements in volunteers. In patients, the only significant difference was found in post-contrast T1 (p = 0.04). ICC showed moderate to excellent agreement in all measurements. PTC performance was equivalent to ECG in terms of triggering consistency, image quality, and quantitative image measurements across multiple CMR applications.
Collapse
Affiliation(s)
- Yue Pan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Juliet Varghese
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Matthew S Tong
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Vedat O Yildiz
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Alessia Azzu
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK
| | - Peter Gatehouse
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK
| | - Rick Wage
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK
| | | | - Dudley J Pennell
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, UK
| | - Ning Jin
- Cardiovascular MR R&D, Siemens Medical Solutions USA, Malvern, PA, USA
| | - Mario Bacher
- Siemens Healthineers AG, Erlangen, Germany
- Department of Diagnostic and Interventional Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | | | | | - Orlando P Simonetti
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA.
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Internal Medicine, Division of Cardiovascular Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
| |
Collapse
|
2
|
Moscatelli S, Gatehouse P, Krupickova S, Mohiaddin R, Voges I, Giese D, Nielles-Vallespin S, Pennell DJ. Impact of compressed sensing (CS) acceleration of two-dimensional (2D) flow sequences in clinical paediatric cardiovascular magnetic resonance (CMR). MAGMA 2023; 36:869-876. [PMID: 37202654 PMCID: PMC10667407 DOI: 10.1007/s10334-023-01098-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/20/2023]
Abstract
OBJECTIVES Two-dimensional (2D) through-plane phase-contrast (PC) cine flow imaging assesses shunts and valve regurgitations in paediatric CMR and is considered the reference standard for Clinical quantification of blood Flow (COF). However, longer breath-holds (BH) can reduce compliance with possibly large respiratory manoeuvres altering flow. We hypothesize that reduced BH time by application of CS (Short BH quantification of Flow) (SBOF) retains accuracy while enabling faster, potentially more reliable flows. We investigate the variance between COF and SBOF cine flows. METHODS Main pulmonary artery (MPA) and sinotubular junction (STJ) planes were acquired at 1.5 T in paediatric patients by COF and SBOF. RESULTS 21 patients (mean age 13.9, 10-17y) were enrolled. The BH times were COF mean 11.7 s (range 8.4-20.9 s) vs SBOF mean 6.5 s (min 3.6-9.1 s). The differences and 95% CI between the COF and SBOF flows were LVSV -1.43 ± 13.6(ml/beat), LVCO 0.16 ± 1.35(l/min) and RVSV 2.95 ± 12.3(ml/beat), RVCO 0.27 ± 0.96(l/min), QP/QS were SV 0.04 ± 0.19, CO 0.02 ± 0.23. Variability between COF and SBOF did not exceed intrasession variation of COF. CONCLUSION SBOF reduces breath-hold duration to 56% of COF. RV flow by SBOF was biased compared to COF. The variation (95% CI) between COF and SBOF was similar to the COF intrasession test-retest 95% CI.
Collapse
Affiliation(s)
- Sara Moscatelli
- Department of Paediatric Cardiology, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Department of CMR, Royal Brompton Hospital, Part of Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK
| | - Peter Gatehouse
- Department of CMR, Royal Brompton Hospital, Part of Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK.
- National Heart and Lung Institute, Imperial College, London, England.
| | - Sylvia Krupickova
- Department of Paediatric Cardiology, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Department of CMR, Royal Brompton Hospital, Part of Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, England
| | - Raad Mohiaddin
- Department of CMR, Royal Brompton Hospital, Part of Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, England
| | - Inga Voges
- Department of Congenital Heart Disease and Pediatric Cardiology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Daniel Giese
- Magnetic Resonance, Siemens Healthcare GmbH, Erlangen, Germany
| | - Sonia Nielles-Vallespin
- Department of CMR, Royal Brompton Hospital, Part of Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, England
| | - Dudley J Pennell
- Department of CMR, Royal Brompton Hospital, Part of Guy's and St Thomas' NHS Foundation Trust, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, London, England
| |
Collapse
|
3
|
Xing X, Ser JD, Wu Y, Li Y, Xia J, Xu L, Firmin D, Gatehouse P, Yang G. HDL: Hybrid Deep Learning for the Synthesis of Myocardial Velocity Maps in Digital Twins for Cardiac Analysis. IEEE J Biomed Health Inform 2023; 27:5134-5142. [PMID: 35290192 DOI: 10.1109/jbhi.2022.3158897] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Synthetic digital twins based on medical data accelerate the acquisition, labelling and decision making procedure in digital healthcare. A core part of digital healthcare twins is model-based data synthesis, which permits the generation of realistic medical signals without requiring to cope with the modelling complexity of anatomical and biochemical phenomena producing them in reality. Unfortunately, algorithms for cardiac data synthesis have been so far scarcely studied in the literature. An important imaging modality in the cardiac examination is three-directional CINE multi-slice myocardial velocity mapping (3Dir MVM), which provides a quantitative assessment of cardiac motion in three orthogonal directions of the left ventricle. The long acquisition time and complex acquisition produce make it more urgent to produce synthetic digital twins of this imaging modality. In this study, we propose a hybrid deep learning (HDL) network, especially for synthetic 3Dir MVM data. Our algorithm is featured by a hybrid UNet and a Generative Adversarial Network with a foreground-background generation scheme. The experimental results show that from temporally down-sampled magnitude CINE images (six times), our proposed algorithm can still successfully synthesise high temporal resolution 3Dir MVM CMR data (PSNR=42.32) with precise left ventricle segmentation (DICE=0.92). These performance scores indicate that our proposed HDL algorithm can be implemented in real-world digital twins for myocardial velocity mapping data simulation. To the best of our knowledge, this work is the first one investigating digital twins of the 3Dir MVM CMR, which has shown great potential for improving the efficiency of clinical studies via synthesised cardiac data.
Collapse
|
4
|
Pan Y, Varghese J, Tong MS, Yildiz VO, Azzu A, Gatehouse P, Wage R, Nielles-Vallespin S, Pennell D, Jin N, Bacher M, Hayes C, Speier P, Simonetti OP. Two-center validation of Pilot Tone Based Cardiac Triggering of a Comprehensive Cardiovascular Magnetic Resonance Examination. Res Sq 2023:rs.3.rs-3121723. [PMID: 37461505 PMCID: PMC10350216 DOI: 10.21203/rs.3.rs-3121723/v1] [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] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Background The electrocardiogram (ECG) signal is prone to distortions from gradient and radiofrequency interference and the magnetohydrodynamic effect during cardiovascular magnetic resonance imaging (CMR). Although Pilot Tone Cardiac (PTC) triggering has the potential to overcome these limitations, effectiveness across various CMR techniques has yet to be established. Purpose To evaluate the performance of PTC triggering in a comprehensive CMR exam. Methods Fifteen volunteers and twenty patients were recruited at two centers. ECG triggered images were collected for comparison in a subset of sequences. The PTC trigger accuracy was evaluated against ECG in cine acquisitions. Two experienced readers scored image quality in PTC-triggered cine, late gadolinium enhancement (LGE), and T1- and T2-weighted dark-blood turbo spin echo (DB-TSE) images. Quantitative cardiac function, flow, and parametric mapping values obtained using PTC and ECG triggered sequences were compared. Results Breath-held segmented cine used for trigger timing analysis was collected in 15 volunteers and 14 patients. PTC calibration failed in three volunteers and one patient; ECG trigger recording failed in one patient. Out of 1987 total heartbeats, three mismatched trigger PTC-ECG pairs were found. Image quality scores showed no significant difference between PTC and ECG triggering. There was no significant difference found in quantitative measurements in volunteers. In patients, the only significant difference was found in post-contrast T1 (p = 0.04). ICC showed moderate to excellent agreement in all measurements. Conclusion PTC performance was equivalent to ECG in terms of triggering consistency, image quality, and quantitative image measurements across multiple CMR applications.
Collapse
|
5
|
Allen JJ, Keegan J, Mathew G, Conway M, Jenkins S, Pennell DJ, Nielles-Vallespin S, Gatehouse P, Babu-Narayan SV. Fully-modelled blood-focused variable inversion times for 3D late gadolinium-enhanced imaging. Magn Reson Imaging 2023; 98:44-54. [PMID: 36581215 DOI: 10.1016/j.mri.2022.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 12/27/2022]
Abstract
PURPOSE Variable heart rate during single-cycle inversion-recovery Late Gadolinium-Enhanced (LGE) scanning degrades image quality, which can be mitigated using Variable Inversion Times (VTIs) in real-time response to R-R interval changes. We investigate in vivo and in simulations an extension of a single-cycle VTI method previously applied in 3D LGE imaging, that now fully models the longitudinal magnetisation (fmVTI). METHODS The VTI and fmVTI methods were used to perform 3D LGE scans for 28 3D LGE patients, with qualitative image quality scores assigned for left atrial wall clarity and total ghosting. Accompanying simulations of numerical phantom images were assessed in terms of ghosting of normal myocardium, blood, and myocardial scar. RESULTS The numerical simulations for fmVTI showed a significant decrease in blood ghosting (VTI: 410 ± 710, fmVTI: 68 ± 40, p < 0.0005) and scar ghosting (VTI: 830 ± 1300, fmVTI: 510 ± 730, p < 0.02). Despite this, there was no significant change in qualitative image quality scores, either for left atrial wall clarity (VTI: 2.0 ± 1.0, fmVTI: 1.8 ± 1.0, p > 0.1) or for total ghosting (VTI: 1.9 ± 1.0, fmVTI: 2.0 ± 1.0, p > 0.7). CONCLUSIONS Simulations indicated reduced ghosting with the fmVTI method, due to reduced Mz variability in the blood signal. However, other sources of phase-encode ghosting and blurring appeared to dominate and obscure this finding in the patient studies available.
Collapse
Affiliation(s)
- Jack J Allen
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Jennifer Keegan
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - George Mathew
- Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Miriam Conway
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Sophie Jenkins
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Dudley J Pennell
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Sonia Nielles-Vallespin
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Peter Gatehouse
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom.
| | - Sonya V Babu-Narayan
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Royal Brompton Hospital. Part of Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| |
Collapse
|
6
|
Moscatelli S, Nielles-Vallespin S, Pennell DJ, Krupickova S, Gatehouse P. Impact of compressed sensing (CS) acceleration of two-dimensional (2D) flow sequences in clinical paediatric cardiac magnetic resonance (CMR). Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Two-dimensional (2D) through-plane phase-contrast (PC) cine flow imaging assesses shunts and valve regurgitations in paediatric CMR, and is considered the reference standard for Clinical quantification Of blood Flow (COF). However, the longer breath-hold (BH) for a flow cine can reduce patient compliance with possibly large respiratory maneuvers altering flow. Compressed sensing (CS) flow has not been widely evaluated in pediatric clinical CMR, although CS flow reduces scan time with persistent accuracy [1–3]. Kocaoglu et al applied CS to ascending and descending aorta and SVC with good results. We used main pulmonary artery (MPA) and sinotubular junction (STJ) planes as usual for clinical CMR.
Purpose
We hypothesise that reduced BH time by modest application of CS to 2D cine through-plane flows (Short BH quantification of Flow) (SBOF) retains accuracy while enabling faster and potentially more reliable paediatric flows. We therefore investigate the variance between conventional COF and new SBOF cine flows in paediatric CMR.
Methods
Paediatric patients were enrolled. Aortic (AO) and MPA COFs were planned from cines of the left and right ventricular outflow tracts. For AO flow the plane was placed at the STJ, and MPA flow was acquired above the pulmonary valve. The same planes were used for COF and SBOF flows at nominally similar parameters except the moderate application of CS exploiting redundancy across the cine frames, SBOF being segmented CS cines not real-time. CVI42 (5.10; Circle CVI) was used for flow analysis (single observer, 3 years' experience). Paired t-tests found the overall differences, and variability was defined at ±2SD for STJSV, MPASV, STJCO, MPACO, and Qp/Qs.
Results and discussion
20 patients (mean age 13.7, range 10–17y) were enrolled (12 CHDs, 7 cardiomyopathies or other diseases). The BH times were COF mean 11.7s (range 8.4–20.9s) vs SBOF mean 6.5s (min 3.6–9.1s). For STJ flows the differences and variabilities between the COF and SBOF flows were SV 6.95±13.6 (ml/beat), CO 0.16±1.35 (l/min) and for MPA flows SV 2.95±12.3 (ml/beat), CO 0.27±0.96 (l/min) and for Qp/Qs were 0.04±0.19 by ml/beat and 0.02±0.23 by l/min. The mean differences were non significant, and variability between SBOF and COF was similar to intrasession repeatability of COF in a separate paediatric population at our centre (unpublished), that might arise from physiological flow changes, possibly in terms of pre and post load and heart rate. With shorter BHs also assisting patient compliance of the SBOF, physiological flow effects might be reduced, although given the variability in COV this was unconfirmed.
Conclusion
Moderate CS applied to clinical segmented-cine paediatric phase-contrast flows in the STJ and MPA planes did not degrade flow repeatability or cause bias. SBOF assists clinical flows by shorter BHs and also may aid compliance and reduce physiological variations.
Funding Acknowledgement
Type of funding sources: None.
Collapse
Affiliation(s)
- S Moscatelli
- Royal Brompton and Harefield Hospital , London , United Kingdom
| | | | - D J Pennell
- Royal Brompton and Harefield Hospital , London , United Kingdom
| | - S Krupickova
- Royal Brompton and Harefield Hospital , London , United Kingdom
| | - P Gatehouse
- Royal Brompton and Harefield Hospital , London , United Kingdom
| |
Collapse
|
7
|
Puricelli F, Voges I, Gatehouse P, Rigby M, Izgi C, Pennell DJ, Krupickova S. Performance of Cardiac MRI in Pediatric and Adult Patients with Fontan Circulation. Radiol Cardiothorac Imaging 2022; 4:e210235. [PMID: 35833165 PMCID: PMC9274315 DOI: 10.1148/ryct.210235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 04/11/2022] [Accepted: 04/18/2022] [Indexed: 06/15/2023]
Abstract
Cardiac MRI has become a widely accepted standard for anatomic and functional assessment of complex Fontan physiology, because it is noninvasive and suitable for comprehensive follow-up evaluation after Fontan completion. The use of cardiac MRI in pediatric and adult patients after completion of the Fontan procedure are described, and a practical and experience-based cardiac MRI protocol for evaluating these patients is provided. The current approach and study protocol in use at the authors' institution are presented, which address technical considerations concerning sequences, planning, and optimal image acquisition in patients with Fontan circulation. Additionally, for each sequence, the information that can be obtained and guidance on how to integrate it into clinical decision-making is discussed. Keywords: Pediatrics, MRI, MRI Functional Imaging, Heart, Congenital © RSNA, 2022.
Collapse
|
8
|
Hatipoglu S, Gatehouse P, Krupickova S, Banya W, Daubeney P, Almogheer B, Izgi C, Weale P, Hayes C, Firmin D, Pennell DJ. Reliability of pediatric ventricular function analysis by short-axis "single-cycle-stack-advance" single-shot compressed-sensing cines in minimal breath-hold time. Eur Radiol 2021; 32:2581-2593. [PMID: 34713331 PMCID: PMC8921124 DOI: 10.1007/s00330-021-08335-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 07/09/2021] [Accepted: 07/23/2021] [Indexed: 12/28/2022]
Abstract
Objectives Cardiovascular magnetic resonance (CMR) cine imaging by compressed sensing (CS) is promising for patients unable to tolerate long breath-holding. However, the need for a steady-state free-precession (SSFP) preparation cardiac cycle for each slice extends the breath-hold duration (e.g. for 10 slices, 20 cardiac cycles) to an impractical length. We investigated a method reducing breath-hold duration by half and assessed its reliability for biventricular volume analysis in a pediatric population. Methods Fifty-five consecutive pediatric patients (median age 12 years, range 7–17) referred for assessment of congenital heart disease or cardiomyopathy were included. Conventional multiple breath-hold SSFP short-axis (SAX) stack cines served as the reference. Real-time CS SSFP cines were applied without the steady-state preparation cycle preceding each SAX cine slice, accepting the limitation of omitting late diastole. The total acquisition time was 1 RR interval/slice. Volumetric analysis was performed for conventional and “single-cycle-stack-advance” (SCSA) cine stacks. Results Bland–Altman analyses [bias (limits of agreement)] showed good agreement in left ventricular (LV) end-diastolic volume (EDV) [3.6 mL (− 5.8, 12.9)], LV end-systolic volume (ESV) [1.3 mL (− 6.0, 8.6)], LV ejection fraction (EF) [0.1% (− 4.9, 5.1)], right ventricular (RV) EDV [3.5 mL (− 3.34, 10.0)], RV ESV [− 0.23 mL (− 7.4, 6.9)], and RV EF [1.70%, (− 3.7, 7.1)] with a trend toward underestimating LV and RV EDVs with the SCSA method. Image quality was comparable for both methods (p = 0.37). Conclusions LV and RV volumetric parameters agreed well between the SCSA and the conventional sequences. The SCSA method halves the breath-hold duration of the commercially available CS sequence and is a reliable alternative for volumetric analysis in a pediatric population. Key Points • Compressed sensing is a promising accelerated cardiovascular magnetic resonance imaging technique. • We omitted the steady-state preparation cardiac cycle preceding each cine slice in compressed sensing and achieved an acquisition speed of 1 RR interval/slice. • This modification called “single-cycle-stack-advance” enabled the acquisition of an entire short-axis cine stack in a single short breath hold. • When tested in a pediatric patient group, the left and right ventricular volumetric parameters agreed well between the “single-cycle-stack-advance” and the conventional sequences.
Collapse
Affiliation(s)
- Suzan Hatipoglu
- Cardiovascular Magnetic Resonance Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK.
| | - Peter Gatehouse
- Cardiovascular Magnetic Resonance Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | - Sylvia Krupickova
- Cardiovascular Magnetic Resonance Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | - Winston Banya
- Research Office, Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | - Piers Daubeney
- Pediatric Cardiology Department, Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | - Batool Almogheer
- Cardiovascular Magnetic Resonance Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | - Cemil Izgi
- Cardiovascular Magnetic Resonance Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK
| | | | | | - David Firmin
- Cardiovascular Magnetic Resonance Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK.,National Heart & Lung Institute, Imperial College, London, UK
| | - Dudley J Pennell
- Cardiovascular Magnetic Resonance Unit, Royal Brompton & Harefield NHS Foundation Trust, London, UK.,National Heart & Lung Institute, Imperial College, London, UK
| |
Collapse
|
9
|
Bermejo IA, Bautista-Rodriguez C, Fraisse A, Voges I, Gatehouse P, Kang H, Piccinelli E, Rowlinson G, Lane M, Semple T, Moscatelli S, Dwornik M, Lota A, Di Salvo G, Wage R, Prasad SK, Mohiaddin R, Pennell DJ, Thavendiranathan P, Krupickova S. Short-Term sequelae of Multisystem Inflammatory Syndrome in Children Assessed by CMR. JACC Cardiovasc Imaging 2021; 14:1666-1667. [PMID: 33744139 DOI: 10.1016/j.jcmg.2021.01.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/14/2021] [Accepted: 01/27/2021] [Indexed: 11/24/2022]
|
10
|
Raphael CE, Mitchell F, Kanaganayagam GS, Liew AC, Di Pietro E, Vieira MS, Kanapeckaite L, Newsome S, Gregson J, Owen R, Hsu LY, Vassiliou V, Cooper R, Mrcp AA, Ismail TF, Wong B, Sun K, Gatehouse P, Firmin D, Cook S, Frenneaux M, Arai A, O'Hanlon R, Pennell DJ, Prasad SK. Cardiovascular magnetic resonance predictors of heart failure in hypertrophic cardiomyopathy: the role of myocardial replacement fibrosis and the microcirculation. J Cardiovasc Magn Reson 2021; 23:26. [PMID: 33685501 PMCID: PMC7941878 DOI: 10.1186/s12968-021-00720-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 04/23/2020] [Revised: 12/10/2020] [Accepted: 01/31/2021] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Heart failure (HF) in hypertrophic cardiomyopathy (HCM) is associated with high morbidity and mortality. Predictors of HF, in particular the role of myocardial fibrosis and microvascular ischemia remain unclear. We assessed the predictive value of cardiovascular magnetic resonance (CMR) for development of HF in HCM in an observational cohort study. METHODS Serial patients with HCM underwent CMR, including adenosine first-pass perfusion, left atrial (LA) and left ventricular (LV) volumes indexed to body surface area (i) and late gadolinium enhancement (%LGE- as a % of total myocardial mass). We used a composite endpoint of HF death, cardiac transplantation, and progression to NYHA class III/IV. RESULTS A total of 543 patients with HCM underwent CMR, of whom 94 met the composite endpoint at baseline. The remaining 449 patients were followed for a median of 5.6 years. Thirty nine patients (8.7%) reached the composite endpoint of HF death (n = 7), cardiac transplantation (n = 2) and progression to NYHA class III/IV (n = 20). The annual incidence of HF was 2.0 per 100 person-years, 95% CI (1.6-2.6). Age, previous non-sustained ventricular tachycardia, LV end-systolic volume indexed to body surface area (LVESVI), LA volume index ; LV ejection fraction, %LGE and presence of mitral regurgitation were significant univariable predictors of HF, with LVESVI (Hazard ratio (HR) 1.44, 95% confidence interval (95% CI) 1.16-1.78, p = 0.001), %LGE per 10% (HR 1.44, 95%CI 1.14-1.82, p = 0.002) age (HR 1.37, 95% CI 1.06-1.77, p = 0.02) and mitral regurgitation (HR 2.6, p = 0.02) remaining independently predictive on multivariable analysis. The presence or extent of inducible perfusion defect assessed using a visual score did not predict outcome (p = 0.16, p = 0.27 respectively). DISCUSSION The annual incidence of HF in a contemporary ambulatory HCM population undergoing CMR is low. Myocardial fibrosis and LVESVI are strongly predictive of future HF, however CMR visual assessment of myocardial perfusion was not.
Collapse
Affiliation(s)
- Claire E Raphael
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.
- Department of CMR, Royal Brompton Hospital, Sydney Street, Sydney, SW3 6NP, UK.
| | - Frances Mitchell
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | | | - Alphonsus C Liew
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Elisa Di Pietro
- Department of Advanced Biomedical Sciences, University of Naples, Naples, Italy
| | - Miguel Silva Vieira
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Lina Kanapeckaite
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Simon Newsome
- London School of Hygiene & Tropical Medicine, London, UK
| | - John Gregson
- London School of Hygiene & Tropical Medicine, London, UK
| | - Ruth Owen
- London School of Hygiene & Tropical Medicine, London, UK
| | - Li-Yueh Hsu
- Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Vassilis Vassiliou
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Robert Cooper
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Aamir Ali Mrcp
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Tevfik F Ismail
- King's College London & Guy's and St Thomas' NHS Foundation Trust, London, UK
| | - Brandon Wong
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Kristi Sun
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Peter Gatehouse
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - David Firmin
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Stuart Cook
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
- National Heart Center, Singapore, Singapore
| | | | - Andrew Arai
- Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | | | - Dudley J Pennell
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Sanjay K Prasad
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| |
Collapse
|
11
|
Wu Y, Hatipoglu S, Alonso-Álvarez D, Gatehouse P, Li B, Gao Y, Firmin D, Keegan J, Yang G. Fast and Automated Segmentation for the Three-Directional Multi-Slice Cine Myocardial Velocity Mapping. Diagnostics (Basel) 2021; 11:346. [PMID: 33669747 PMCID: PMC7922945 DOI: 10.3390/diagnostics11020346] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 02/05/2021] [Accepted: 02/17/2021] [Indexed: 12/29/2022] Open
Abstract
Three-directional cine multi-slice left ventricular myocardial velocity mapping (3Dir MVM) is a cardiac magnetic resonance (CMR) technique that allows the assessment of cardiac motion in three orthogonal directions. Accurate and reproducible delineation of the myocardium is crucial for accurate analysis of peak systolic and diastolic myocardial velocities. In addition to the conventionally available magnitude CMR data, 3Dir MVM also provides three orthogonal phase velocity mapping datasets, which are used to generate velocity maps. These velocity maps may also be used to facilitate and improve the myocardial delineation. Based on the success of deep learning in medical image processing, we propose a novel fast and automated framework that improves the standard U-Net-based methods on these CMR multi-channel data (magnitude and phase velocity mapping) by cross-channel fusion with an attention module and the shape information-based post-processing to achieve accurate delineation of both epicardial and endocardial contours. To evaluate the results, we employ the widely used Dice Scores and the quantification of myocardial longitudinal peak velocities. Our proposed network trained with multi-channel data shows superior performance compared to standard U-Net-based networks trained on single-channel data. The obtained results are promising and provide compelling evidence for the design and application of our multi-channel image analysis of the 3Dir MVM CMR data.
Collapse
Affiliation(s)
- Yinzhe Wu
- National Heart & Lung Institute, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (P.G.); (D.F.); (J.K.)
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London SW7 2AZ, UK;
| | - Suzan Hatipoglu
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London SW3 6NP, UK;
| | - Diego Alonso-Álvarez
- Research Computing Service, Information & Communication Technologies, Imperial College London, London SW7 2AZ, UK;
| | - Peter Gatehouse
- National Heart & Lung Institute, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (P.G.); (D.F.); (J.K.)
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London SW3 6NP, UK;
| | - Binghuan Li
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London SW7 2AZ, UK;
| | - Yikai Gao
- Department of Computing, Faculty of Engineering, Imperial College London, London SW7 2AZ, UK;
| | - David Firmin
- National Heart & Lung Institute, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (P.G.); (D.F.); (J.K.)
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London SW3 6NP, UK;
| | - Jennifer Keegan
- National Heart & Lung Institute, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (P.G.); (D.F.); (J.K.)
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London SW3 6NP, UK;
| | - Guang Yang
- National Heart & Lung Institute, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK; (P.G.); (D.F.); (J.K.)
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London SW3 6NP, UK;
| |
Collapse
|
12
|
Raphael CE, Liew AC, Mitchell F, Kanaganayagam GS, Di Pietro E, Newsome S, Owen R, Gregson J, Cooper R, Amin FR, Gatehouse P, Vassiliou V, Ernst S, O'Hanlon R, Frenneaux M, Pennell DJ, Prasad SK. Predictors and Mechanisms of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy. Am J Cardiol 2020; 136:140-148. [PMID: 32950468 DOI: 10.1016/j.amjcard.2020.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/26/2020] [Accepted: 09/01/2020] [Indexed: 11/16/2022]
Abstract
Atrial fibrillation (AF) in hypertrophic cardiomyopathy (HC) is associated with significant symptomatic deterioration, heart failure, and thromboembolic disease. There is a need for better mechanistic insight and improved identification of at risk patients. We used cardiovascular magnetic resonance (CMR) to assess predictors of AF in HC, in particular the role of myocardial fibrosis. Consecutive patients with HC referred for CMR 2003 to 2013 were prospectively enrolled. CMR parameters including left ventricular volumes, presence and percentage of late gadolinium enhancement in the left ventricle (%LGE) and left atrial volume index (LAVi) were measured. Overall, 377 patients were recruited (age 62 ± 14 years, 73% men). Sixty-two patients (16%) developed new-onset AF during a median follow up of 4.5 (interquartile range 2.9 to 6.0) years. Multivariable analysis revealed %LGE (hazard ratio [HR] 1.3 per 10% (confidence interval: 1.0 to 1.5; p = 0.02), LAVi (HR 1.4 per 10 mL/m2[1.2 to 1.5; p < 0.001]), age at HC diagnosis, nonsustained ventricular tachycardia and diabetes to be independent predictors of AF. We constructed a simple risk prediction score for future AF based on the multivariable model with a Harrell's C-statistic of 0.73. In conclusion, the extent of ventricular fibrosis and LA volume independently predicted AF in patients with HC. This finding suggests a mechanistic relation between fibrosis and future AF in HC. CMR with quantification of fibrosis has incremental value over LV and LA measurements in risk stratification for AF. A risk prediction score may be used to identify patients at high risk of future AF who may benefit from more intensive rhythm monitoring and a lower threshold for oral anticoagulation.
Collapse
Affiliation(s)
- Claire E Raphael
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.
| | - Alphonsus C Liew
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Frances Mitchell
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | | | - Elisa Di Pietro
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Simon Newsome
- Department of Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Ruth Owen
- Department of Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - John Gregson
- Department of Statistics, London School of Hygiene & Tropical Medicine, London, UK
| | - Robert Cooper
- Department of Cardiology, Liverpool Heart and Chest Hospital, Liverpool, UK
| | - Fouad R Amin
- Department of Cardiology, Frimley Park Hospital, Camberley, UK
| | - Peter Gatehouse
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | | | - Sabine Ernst
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Rory O'Hanlon
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | | | - Dudley J Pennell
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Sanjay K Prasad
- IHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| |
Collapse
|
13
|
Mahon C, Gatehouse P, Baksi J, Mohiaddin RH. The mysterious needle in the heart: a case report. Eur Heart J Case Rep 2020; 4:1-4. [PMID: 33043238 PMCID: PMC7534165 DOI: 10.1093/ehjcr/ytaa083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/31/2019] [Accepted: 03/17/2020] [Indexed: 11/18/2022]
Abstract
Background A 53-year-old female with dyspnoea and atypical chest pain. Her electrocardiogram demonstrated a left bundle branch block, transthoracic echocardiogram demonstrated a mildly impaired left ventricle ejection fraction, and coronary angiogram revealed unobstructed coronary arteries. She was referred for cardiovascular magnetic resonance (CMR) for structural and functional assessment. Her imaging revealed an unexpected finding of an off-resonance artefact within the ventricle wall. This material was secondary to a ferromagnetic material. Case summary Chest X ray and computer tomography confirmed a needle-shaped structure in the ventricle wall. Understanding the basis of this off-resonance artefact aided in a new diagnosis, raised questions on the origin of the material, patient safety, and implementation of corrective strategies to optimize image acquisition. Discussion The continued development of CMR is revolutionizing our ability to establish diagnosis and guide patient treatment. The CMR sequences can be prone to artefact. This case highlights the importance of understanding the basis of CMR artefacts.
Collapse
Affiliation(s)
- Ciara Mahon
- Department of Cardiovascular Magnetic Resonance, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
| | - Peter Gatehouse
- Department of Cardiovascular Magnetic Resonance, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
| | - John Baksi
- Department of Cardiovascular Magnetic Resonance, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
- National Heart and Lung Institute, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Raad H Mohiaddin
- Department of Cardiovascular Magnetic Resonance, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
| |
Collapse
|
14
|
Captur G, Bhandari A, Brühl R, Ittermann B, Keenan KE, Yang Y, Eames RJ, Benedetti G, Torlasco C, Ricketts L, Boubertakh R, Fatih N, Greenwood JP, Paulis LEM, Lawton CB, Bucciarelli-Ducci C, Lamb HJ, Steeds R, Leung SW, Berry C, Valentin S, Flett A, de Lange C, DeCobelli F, Viallon M, Croisille P, Higgins DM, Greiser A, Pang W, Hamilton-Craig C, Strugnell WE, Dresselaers T, Barison A, Dawson D, Taylor AJ, Mongeon FP, Plein S, Messroghli D, Al-Mallah M, Grieve SM, Lombardi M, Jang J, Salerno M, Chaturvedi N, Kellman P, Bluemke DA, Nezafat R, Gatehouse P, Moon JC. T 1 mapping performance and measurement repeatability: results from the multi-national T 1 mapping standardization phantom program (T1MES). J Cardiovasc Magn Reson 2020; 22:31. [PMID: 32375896 PMCID: PMC7204222 DOI: 10.1186/s12968-020-00613-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [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: 04/06/2019] [Accepted: 03/02/2020] [Indexed: 04/03/2023] Open
Abstract
BACKGROUND The T1 Mapping and Extracellular volume (ECV) Standardization (T1MES) program explored T1 mapping quality assurance using a purpose-developed phantom with Food and Drug Administration (FDA) and Conformité Européenne (CE) regulatory clearance. We report T1 measurement repeatability across centers describing sequence, magnet, and vendor performance. METHODS Phantoms batch-manufactured in August 2015 underwent 2 years of structural imaging, B0 and B1, and "reference" slow T1 testing. Temperature dependency was evaluated by the United States National Institute of Standards and Technology and by the German Physikalisch-Technische Bundesanstalt. Center-specific T1 mapping repeatability (maximum one scan per week to minimum one per quarter year) was assessed over mean 358 (maximum 1161) days on 34 1.5 T and 22 3 T magnets using multiple T1 mapping sequences. Image and temperature data were analyzed semi-automatically. Repeatability of serial T1 was evaluated in terms of coefficient of variation (CoV), and linear mixed models were constructed to study the interplay of some of the known sources of T1 variation. RESULTS Over 2 years, phantom gel integrity remained intact (no rips/tears), B0 and B1 homogenous, and "reference" T1 stable compared to baseline (% change at 1.5 T, 1.95 ± 1.39%; 3 T, 2.22 ± 1.44%). Per degrees Celsius, 1.5 T, T1 (MOLLI 5s(3s)3s) increased by 11.4 ms in long native blood tubes and decreased by 1.2 ms in short post-contrast myocardium tubes. Agreement of estimated T1 times with "reference" T1 was similar across Siemens and Philips CMR systems at both field strengths (adjusted R2 ranges for both field strengths, 0.99-1.00). Over 1 year, many 1.5 T and 3 T sequences/magnets were repeatable with mean CoVs < 1 and 2% respectively. Repeatability was narrower for 1.5 T over 3 T. Within T1MES repeatability for native T1 was narrow for several sequences, for example, at 1.5 T, Siemens MOLLI 5s(3s)3s prototype number 448B (mean CoV = 0.27%) and Philips modified Look-Locker inversion recovery (MOLLI) 3s(3s)5s (CoV 0.54%), and at 3 T, Philips MOLLI 3b(3s)5b (CoV 0.33%) and Siemens shortened MOLLI (ShMOLLI) prototype 780C (CoV 0.69%). After adjusting for temperature and field strength, it was found that the T1 mapping sequence and scanner software version (both P < 0.001 at 1.5 T and 3 T), and to a lesser extent the scanner model (P = 0.011, 1.5 T only), had the greatest influence on T1 across multiple centers. CONCLUSION The T1MES CE/FDA approved phantom is a robust quality assurance device. In a multi-center setting, T1 mapping had performance differences between field strengths, sequences, scanner software versions, and manufacturers. However, several specific combinations of field strength, sequence, and scanner are highly repeatable, and thus, have potential to provide standardized assessment of T1 times for clinical use, although temperature correction is required for native T1 tubes at least.
Collapse
Affiliation(s)
- Gabriella Captur
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
- UCL MRC Unit for Lifelong Health and Ageing, University College London, 1-19 Torrington Place, London, WC1E 7BH UK
- Cardiology Department, The Royal Free Hospital, Centre for Inherited Heart Muscle Conditions, Pond Street, Hampstead, London, NW3 2QG UK
| | - Abhiyan Bhandari
- UCL Medical School, University College London, Bloomsbury Campus, Gower Street, London, WC1E 6BT UK
| | - Rüdiger Brühl
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2–12, D-10587 Berlin, Germany
| | - Bernd Ittermann
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2–12, D-10587 Berlin, Germany
| | - Kathryn E. Keenan
- National Institute of Standards and Technology (NIST), Boulder, MS 818.03, 325 Broadway, Boulder, CO USA
| | - Ye Yang
- Department of Cardiology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, 310016 Zhejiang People’s Republic of China
| | - Richard J. Eames
- Department of Physics, Imperial College London, Prince Consort Rd, London, SW7 2BB UK
| | - Giulia Benedetti
- Department of Radiology, Guys and St Thomas NHS Foundation Trust, London, UK
| | - Camilla Torlasco
- University of Milan-Bicocca, Piazza dell’Ateneo Nuovo 1, 20100 Milan, Italy
| | - Lewis Ricketts
- UCL Medical School, University College London, Bloomsbury Campus, Gower Street, London, WC1E 6BT UK
| | - Redha Boubertakh
- Cardiovascular Biomedical Research Unit, Queen Mary University of London, London, E1 4NS UK
| | - Nasri Fatih
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
- UCL MRC Unit for Lifelong Health and Ageing, University College London, 1-19 Torrington Place, London, WC1E 7BH UK
| | - John P. Greenwood
- Multidisciplinary Cardiovascular Research Center & Division of Biomedical Imaging, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Leonie E. M. Paulis
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, PO Box 5800, 6202 AZ Maastricht, The Netherlands
| | - Chris B. Lawton
- Bristol Heart Institute, National Institute of Health Research (NIHR) Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, Upper Maudlin St, Bristol, BS2 8HW UK
| | - Chiara Bucciarelli-Ducci
- Bristol Heart Institute, National Institute of Health Research (NIHR) Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, Upper Maudlin St, Bristol, BS2 8HW UK
| | - Hildo J. Lamb
- Department of Radiology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Richard Steeds
- University Hospitals Birmingham NHS Foundation Trust, Edgbaston, Birmingham, B15 2TH UK
| | - Steve W. Leung
- UK Albert B. Chandler Hospital - Pavilion G, Gill Heart & Vascular Institute, Lexington, KY 40536 USA
| | - Colin Berry
- Institute of Cardiovascular and Medical Sciences, RC309 Level C3, Bhf Gcrc, Glasgow, Scotland G12 8TA UK
| | - Sinitsyn Valentin
- Department of Multidisciplinary Clinical Studies, Lomonosov Moscow State University, Moscow, Russia
| | - Andrew Flett
- University Hospital Southampton Foundation Trust, Tremona Road, Southampton, Hampshire SO16 6YD UK
| | - Charlotte de Lange
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway
| | | | - Magalie Viallon
- INSA, CNRS UMR 5520, INSERM U1206, University of Lyon, UJM-Saint-Etienne, CREATIS, F-42023 Saint-Etienne, France
| | - Pierre Croisille
- Department of Radiology, University Hospital Saint-Etienne, Saint-Etienne, France
| | - David M. Higgins
- Philips, Philips Centre, Unit 3, Guildford Business Park, Guildford, Surrey GU2 8XG UK
| | | | - Wenjie Pang
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
| | - Christian Hamilton-Craig
- The Prince Charles Hospital, Griffith University and University of Queensland, Brisbane, Australia
| | - Wendy E. Strugnell
- The Prince Charles Hospital, Griffith University and University of Queensland, Brisbane, Australia
| | - Tom Dresselaers
- Department of Radiology, Universitair Ziekenhuis Leuven, Leuven, UZ Belgium
| | | | - Dana Dawson
- School of Medicine and Dentistry, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, AB25 2ZD Scotland, UK
| | - Andrew J. Taylor
- Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Australia
- Baker Heart and Diabetes Institute, Melbourne, Australia
- Department of Medicine, Monash University, Melbourne, Australia
| | - François-Pierre Mongeon
- Department of Medicine, Montreal Heart Institute and Université de Montréal, 5000 Bélanger Street, Montreal, QC H1T 1C8 Canada
| | - Sven Plein
- Multidisciplinary Cardiovascular Research Center & Division of Biomedical Imaging, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
| | - Daniel Messroghli
- Department of Internal Medicine – Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany
| | - Mouaz Al-Mallah
- King Abdulaziz Cardiac Center (KACC) (Riyadh), National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Stuart M. Grieve
- The University of Sydney School of Medicine, Camperdown, NSW 2006 Australia
| | - Massimo Lombardi
- I.R.C.C.S., Policlinico San Donato, Piazza Edmondo Malan, 2, 20097 San Donato Milanese, MI Italy
| | - Jihye Jang
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Cardiology East Campus, Room E/SH455, 330 Brookline Ave, Boston, MA 02215 USA
| | - Michael Salerno
- University of Virginia Health System, 1215 Lee St, PO Box 800158, Charlottesville, VA 22908 USA
| | - Nish Chaturvedi
- UCL MRC Unit for Lifelong Health and Ageing, University College London, 1-19 Torrington Place, London, WC1E 7BH UK
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1061 USA
| | - David A. Bluemke
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-3252 USA
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Cardiology East Campus, Room E/SH455, 330 Brookline Ave, Boston, MA 02215 USA
| | - Peter Gatehouse
- CMRI Department, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - James C. Moon
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
- Barts Heart Center, St Bartholomew’s Hospital, West Smithfield, London, EC1A 7BE UK
| | - on behalf of the T1MES Consortium
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
- UCL MRC Unit for Lifelong Health and Ageing, University College London, 1-19 Torrington Place, London, WC1E 7BH UK
- Cardiology Department, The Royal Free Hospital, Centre for Inherited Heart Muscle Conditions, Pond Street, Hampstead, London, NW3 2QG UK
- UCL Medical School, University College London, Bloomsbury Campus, Gower Street, London, WC1E 6BT UK
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2–12, D-10587 Berlin, Germany
- National Institute of Standards and Technology (NIST), Boulder, MS 818.03, 325 Broadway, Boulder, CO USA
- Department of Cardiology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, 310016 Zhejiang People’s Republic of China
- Department of Physics, Imperial College London, Prince Consort Rd, London, SW7 2BB UK
- Department of Radiology, Guys and St Thomas NHS Foundation Trust, London, UK
- University of Milan-Bicocca, Piazza dell’Ateneo Nuovo 1, 20100 Milan, Italy
- Cardiovascular Biomedical Research Unit, Queen Mary University of London, London, E1 4NS UK
- Multidisciplinary Cardiovascular Research Center & Division of Biomedical Imaging, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Centre, PO Box 5800, 6202 AZ Maastricht, The Netherlands
- Bristol Heart Institute, National Institute of Health Research (NIHR) Biomedical Research Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, Upper Maudlin St, Bristol, BS2 8HW UK
- Department of Radiology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- University Hospitals Birmingham NHS Foundation Trust, Edgbaston, Birmingham, B15 2TH UK
- UK Albert B. Chandler Hospital - Pavilion G, Gill Heart & Vascular Institute, Lexington, KY 40536 USA
- Institute of Cardiovascular and Medical Sciences, RC309 Level C3, Bhf Gcrc, Glasgow, Scotland G12 8TA UK
- Department of Multidisciplinary Clinical Studies, Lomonosov Moscow State University, Moscow, Russia
- University Hospital Southampton Foundation Trust, Tremona Road, Southampton, Hampshire SO16 6YD UK
- Department of Radiology and Nuclear Medicine, Oslo University Hospital, Sognsvannsveien 20, 0372 Oslo, Norway
- San Raffaele Hospital, Via Olgettina 60, 20132 Milan, Italy
- INSA, CNRS UMR 5520, INSERM U1206, University of Lyon, UJM-Saint-Etienne, CREATIS, F-42023 Saint-Etienne, France
- Department of Radiology, University Hospital Saint-Etienne, Saint-Etienne, France
- Philips, Philips Centre, Unit 3, Guildford Business Park, Guildford, Surrey GU2 8XG UK
- SiemensHealthcare GmbH, Erlangen, Germany
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
- The Prince Charles Hospital, Griffith University and University of Queensland, Brisbane, Australia
- Department of Radiology, Universitair Ziekenhuis Leuven, Leuven, UZ Belgium
- Fondazione Toscana Gabriele Monasterio, Pisa, Italy
- School of Medicine and Dentistry, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, AB25 2ZD Scotland, UK
- Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Australia
- Baker Heart and Diabetes Institute, Melbourne, Australia
- Department of Medicine, Monash University, Melbourne, Australia
- Department of Medicine, Montreal Heart Institute and Université de Montréal, 5000 Bélanger Street, Montreal, QC H1T 1C8 Canada
- Department of Internal Medicine – Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow Klinikum, Berlin, Germany
- King Abdulaziz Cardiac Center (KACC) (Riyadh), National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
- The University of Sydney School of Medicine, Camperdown, NSW 2006 Australia
- I.R.C.C.S., Policlinico San Donato, Piazza Edmondo Malan, 2, 20097 San Donato Milanese, MI Italy
- Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Cardiology East Campus, Room E/SH455, 330 Brookline Ave, Boston, MA 02215 USA
- University of Virginia Health System, 1215 Lee St, PO Box 800158, Charlottesville, VA 22908 USA
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1061 USA
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-3252 USA
- CMRI Department, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
- Barts Heart Center, St Bartholomew’s Hospital, West Smithfield, London, EC1A 7BE UK
| |
Collapse
|
15
|
Gulati A, Ismail TF, Ali A, Hsu LY, Gonçalves C, Ismail NA, Krishnathasan K, Davendralingam N, Ferreira P, Halliday BP, Jones DA, Wage R, Newsome S, Gatehouse P, Firmin D, Jabbour A, Assomull RG, Mathur A, Pennell DJ, Arai AE, Prasad SK. Microvascular Dysfunction in Dilated Cardiomyopathy: A Quantitative Stress Perfusion Cardiovascular Magnetic Resonance Study. JACC Cardiovasc Imaging 2019; 12:1699-1708. [PMID: 30660522 PMCID: PMC8616858 DOI: 10.1016/j.jcmg.2018.10.032] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 10/01/2018] [Accepted: 10/10/2018] [Indexed: 12/19/2022]
Abstract
OBJECTIVES This study sought to quantify myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) in dilated cardiomyopathy (DCM) and examine the relationship between myocardial perfusion and adverse left ventricular (LV) remodeling. BACKGROUND Although regarded as a nonischemic condition, DCM has been associated with microvascular dysfunction, which is postulated to play a role in its pathogenesis. However, the relationship of the resulting perfusion abnormalities to myocardial fibrosis and the degree of LV remodeling is unclear. METHODS A total of 65 patients and 35 healthy control subjects underwent adenosine (140 μg/kg/min) stress perfusion cardiovascular magnetic resonance with late gadolinium enhancement imaging. Stress and rest MBF and MPR were derived using a modified Fermi-constrained deconvolution algorithm. RESULTS Patients had significantly higher global rest MBF compared with control subjects (1.73 ± 0.42 ml/g/min vs. 1.14 ± 0.42 ml/g/min; p < 0.001). In contrast, global stress MBF was significantly lower versus control subjects (3.07 ± 1.02 ml/g/min vs. 3.53 ± 0.79 ml/g/min; p = 0.02), resulting in impaired MPR in the DCM group (1.83 ± 0.58 vs. 3.50 ± 1.45; p < 0.001). Global stress MBF (2.70 ± 0.89 ml/g/min vs. 3.44 ± 1.03 ml/g/min; p = 0.017) and global MPR (1.67 ± 0.61 vs. 1.99 ± 0.50; p = 0.047) were significantly reduced in patients with DCM with LV ejection fraction ≤35% compared with those with LV ejection fraction >35%. Segments with fibrosis had lower rest MBF (mean difference: -0.12 ml/g/min; 95% confidence interval: -0.23 to -0.01 ml/g/min; p = 0.035) and lower stress MBF (mean difference: -0.15 ml/g/min; 95% confidence interval: -0.28 to -0.03 ml/g/min; p = 0.013). CONCLUSIONS Patients with DCM exhibit microvascular dysfunction, the severity of which is associated with the degree of LV impairment. However, rest MBF is elevated rather than reduced in DCM. If microvascular dysfunction contributes to the pathogenesis of DCM, then the underlying mechanism is more likely to involve stress-induced repetitive stunning rather than chronic myocardial hypoperfusion.
Collapse
Affiliation(s)
| | | | - Aamir Ali
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | - Li-Yueh Hsu
- National Institutes of Health, Bethesda, Maryland
| | | | - Nizar A Ismail
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | - Kaushiga Krishnathasan
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | - Natasha Davendralingam
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | - Pedro Ferreira
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | - Brian P Halliday
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | - Daniel A Jones
- Department of Cardiology, Bart's Health NHS Trust, London, United Kingdom
| | | | - Simon Newsome
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Peter Gatehouse
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | - David Firmin
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| | | | | | - Anthony Mathur
- Department of Cardiology, Bart's Health NHS Trust, London, United Kingdom
| | - Dudley J Pennell
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom.
| | | | - Sanjay K Prasad
- Royal Brompton Hospital, London, United Kingdom; Imperial College London, London, United Kingdom
| |
Collapse
|
16
|
Vassiliou VS, Wassilew K, Cameron D, Heng EL, Nyktari E, Asimakopoulos G, de Souza A, Giri S, Pierce I, Jabbour A, Firmin D, Frenneaux M, Gatehouse P, Pennell DJ, Prasad SK. Identification of myocardial diffuse fibrosis by 11 heartbeat MOLLI T 1 mapping: averaging to improve precision and correlation with collagen volume fraction. MAGMA 2018; 31:101-113. [PMID: 28608326 PMCID: PMC5813064 DOI: 10.1007/s10334-017-0630-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 05/04/2017] [Accepted: 05/24/2017] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Our objectives involved identifying whether repeated averaging in basal and mid left ventricular myocardial levels improves precision and correlation with collagen volume fraction for 11 heartbeat MOLLI T 1 mapping versus assessment at a single ventricular level. MATERIALS AND METHODS For assessment of T 1 mapping precision, a cohort of 15 healthy volunteers underwent two CMR scans on separate days using an 11 heartbeat MOLLI with a 5(3)3 beat scheme to measure native T 1 and a 4(1)3(1)2 beat post-contrast scheme to measure post-contrast T 1, allowing calculation of partition coefficient and ECV. To assess correlation of T 1 mapping with collagen volume fraction, a separate cohort of ten aortic stenosis patients scheduled to undergo surgery underwent one CMR scan with this 11 heartbeat MOLLI scheme, followed by intraoperative tru-cut myocardial biopsy. Six models of myocardial diffuse fibrosis assessment were established with incremental inclusion of imaging by averaging of the basal and mid-myocardial left ventricular levels, and each model was assessed for precision and correlation with collagen volume fraction. RESULTS A model using 11 heart beat MOLLI imaging of two basal and two mid ventricular level averaged T 1 maps provided improved precision (Intraclass correlation 0.93 vs 0.84) and correlation with histology (R 2 = 0.83 vs 0.36) for diffuse fibrosis compared to a single mid-ventricular level alone. ECV was more precise and correlated better than native T 1 mapping. CONCLUSION T 1 mapping sequences with repeated averaging could be considered for applications of 11 heartbeat MOLLI, especially when small changes in native T 1/ECV might affect clinical management.
Collapse
Affiliation(s)
- Vassilios S Vassiliou
- Norwich Medical School, University of East Anglia, Bob Champion Research and Education Building, Norwich Research Park, Norwich, NR4 7UQ, UK.
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK.
- Imperial College, National Heart and Lung Institute, London, UK.
| | - Katharina Wassilew
- The Pathology Department, Rigshospitalet, University Hospital of Copenhagen, Blegdamsvej 9, 2100, Copenhagen, Denmark
| | - Donnie Cameron
- Norwich Medical School, University of East Anglia, Bob Champion Research and Education Building, Norwich Research Park, Norwich, NR4 7UQ, UK
| | - Ee Ling Heng
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Evangelia Nyktari
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | - George Asimakopoulos
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | - Anthony de Souza
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
| | | | - Iain Pierce
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Andrew Jabbour
- Department of Cardiology, St Vincent's Hospital, Darlinghurst, Australia
| | - David Firmin
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Michael Frenneaux
- Norwich Medical School, University of East Anglia, Bob Champion Research and Education Building, Norwich Research Park, Norwich, NR4 7UQ, UK
| | - Peter Gatehouse
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Dudley J Pennell
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, National Heart and Lung Institute, London, UK
| | - Sanjay K Prasad
- CMR Unit and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, National Heart and Lung Institute, London, UK
| |
Collapse
|
17
|
Nyktari E, Vassiliou VS, Arzanauskaite M, Gatehouse P, Greiser A, Wechalekar A, Gilbertson J, Pierce I, Sharma R, Mohiaddin R. Challenging Occam's Razor: An Unusual Combination of Sarcoidosis and Amyloidosis. The Value of Cardiac Magnetic Resonance Imaging in Infiltrative Cardiomyopathies. Can J Cardiol 2017; 33:1335.e9-1335.e11. [PMID: 28870471 DOI: 10.1016/j.cjca.2017.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/10/2017] [Accepted: 07/12/2017] [Indexed: 10/19/2022] Open
Abstract
We describe the case of a 66-year old woman with the extremely rare combination of sarcoidosis and amyloidosis (light chain) and the important role of cardiovascular magnetic resonance imaging to differentiate between these 2 infiltrative diseases. Myocardial characterization with T1 mapping can improve disease detection, especially in overlap cases, and possibly obviate the need for cardiac biopsy.
Collapse
Affiliation(s)
- Eva Nyktari
- Department of Cardiovascular Magnetic Resonance, Royal Brompton and Harefield NHS Trust, London, United Kingdom.
| | - Vassilios S Vassiliou
- Department of Cardiovascular Magnetic Resonance, Royal Brompton and Harefield NHS Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College, London, United Kingdom; Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Monika Arzanauskaite
- Department of Cardiovascular Magnetic Resonance, Royal Brompton and Harefield NHS Trust, London, United Kingdom
| | - Peter Gatehouse
- Department of Cardiovascular Magnetic Resonance, Royal Brompton and Harefield NHS Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College, London, United Kingdom
| | | | - Ashutosh Wechalekar
- University College London and Royal Free London NHS Foundation, London, United Kingdom
| | - Janet Gilbertson
- University College London and Royal Free London NHS Foundation, London, United Kingdom
| | - Iain Pierce
- Department of Cardiovascular Magnetic Resonance, Royal Brompton and Harefield NHS Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Rakesh Sharma
- Department of Cardiovascular Magnetic Resonance, Royal Brompton and Harefield NHS Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Raad Mohiaddin
- Department of Cardiovascular Magnetic Resonance, Royal Brompton and Harefield NHS Trust, London, United Kingdom; National Heart and Lung Institute, Imperial College, London, United Kingdom
| |
Collapse
|
18
|
Liew A, Raphael C, Mitchell F, Kanaganayagam G, Di Pietro E, Newsome S, Cooper R, Gatehouse P, Vassiliou V, Pennell D, Frenneaux M, O'Hanlon R, Prasad S. P4510Prognostic value of cardiovascular magnetic resonance in the prediction of atrial fibrillation in hypertrophic cardiomyopathy (HCM). Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx504.p4510] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
19
|
Tsao A, Lota A, Wassall R, Baksi J, Alpendurada F, Nyktari E, Gatehouse P, Firmin D, Cook S, Ware J, Cleland J, Pennell D, Prasad S. 50 Incremental diagnostic value of cardiovascular magnetic resonance in young adult survivors of sudden cardiac arrest. Heart 2017. [DOI: 10.1136/heartjnl-2017-311726.49] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
20
|
Lota A, Baksi J, Tsao A, Mouy F, Wassall R, Halliday B, Tayal U, Izgi C, Alpendurada F, Nyktari E, Wage R, Gatehouse P, Kilner P, Mohiaddin R, Firmin D, Ware J, Cleland J, Cook S, Pennell D, Prasad S. CARDIOVASCULAR MAGNETIC RESONANCE IN SURVIVORS OF SUDDEN CARDIAC ARREST: 14 YEAR EXPERIENCE FROM A TERTIARY REFERRAL CENTRE IN THE UNITED KINGDOM. J Am Coll Cardiol 2017. [DOI: 10.1016/s0735-1097(17)33880-9] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
21
|
Mathew GL, Vassiliou V, Heng EL, Smith GC, Anita S, Unnikrishnan N, Alpendurada F, Pennell DJ, Gatehouse P, Symmonds K, Prasad S. Streamlining trigger delay estimation for T1 mapping. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032755 DOI: 10.1186/1532-429x-18-s1-t11] [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
|
22
|
Fair MJ, Gatehouse P, DiBella EV, Chen L, Wage R, Firmin D. An extended 3D whole-heart myocardial first-pass perfusion sequence: alternate-cycle views with isotropic and high-resolution imaging. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032376 DOI: 10.1186/1532-429x-18-s1-q60] [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: 11/21/2022] Open
|
23
|
Hsu LY, Kellman P, Gatehouse P, Conn HM, Benovoy M, Jacobs M, Arai AE. Correlations and validations of dual-bolus and dual-sequence quantification of first-pass myocardial perfusion CMR in humans and canines. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032113 DOI: 10.1186/1532-429x-18-s1-q17] [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: 11/30/2022] Open
|
24
|
Wage R, Gatehouse P, Jasmin NH, Pennell DJ. Myocardial T1 and ECV mapping: how we optimise technical aspects of acquisition. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032217 DOI: 10.1186/1532-429x-18-s1-t9] [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: 12/03/2022] Open
|
25
|
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
|
26
|
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
|
27
|
Captur G, Gatehouse P, Keenan KE, Heslinga FG, Bruehl R, Prothmann M, Graves MJ, Eames RJ, Torlasco C, Benedetti G, Donovan J, Ittermann B, Boubertakh R, Bathgate A, Royet C, Pang W, Nezafat R, Salerno M, Kellman P, Moon JC. A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance-the T 1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program. J Cardiovasc Magn Reson 2016; 18:58. [PMID: 27660042 PMCID: PMC5034411 DOI: 10.1186/s12968-016-0280-z] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 09/02/2016] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND T1 mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T1 mapping to global clinical care, we developed a phantom-based quality assurance (QA) system for verification of measurement stability over time at individual sites, with further aims of generalization of results across sites, vendor systems, software versions and imaging sequences. We thus created T1MES: The T1 Mapping and ECV Standardization Program. METHODS A design collaboration consisting of a specialist MRI small-medium enterprise, clinicians, physicists and national metrology institutes was formed. A phantom was designed covering clinically relevant ranges of T1 and T2 in blood and myocardium, pre and post-contrast, for 1.5 T and 3 T. Reproducible mass manufacture was established. The device received regulatory clearance by the Food and Drug Administration (FDA) and Conformité Européene (CE) marking. RESULTS The T1MES phantom is an agarose gel-based phantom using nickel chloride as the paramagnetic relaxation modifier. It was reproducibly specified and mass-produced with a rigorously repeatable process. Each phantom contains nine differently-doped agarose gel tubes embedded in a gel/beads matrix. Phantoms were free of air bubbles and susceptibility artifacts at both field strengths and T1 maps were free from off-resonance artifacts. The incorporation of high-density polyethylene beads in the main gel fill was effective at flattening the B 1 field. T1 and T2 values measured in T1MES showed coefficients of variation of 1 % or less between repeat scans indicating good short-term reproducibility. Temperature dependency experiments confirmed that over the range 15-30 °C the short-T1 tubes were more stable with temperature than the long-T1 tubes. A batch of 69 phantoms was mass-produced with random sampling of ten of these showing coefficients of variations for T1 of 0.64 ± 0.45 % and 0.49 ± 0.34 % at 1.5 T and 3 T respectively. CONCLUSION The T1MES program has developed a T1 mapping phantom to CE/FDA manufacturing standards. An initial 69 phantoms with a multi-vendor user manual are now being scanned fortnightly in centers worldwide. Future results will explore T1 mapping sequences, platform performance, stability and the potential for standardization.
Collapse
Affiliation(s)
- Gabriella Captur
- UCL Biological Mass Spectrometry Laboratory, Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London, UK
- NIHR University College London Hospitals Biomedical Research Center, Maple House Suite, Tottenham Court Road, London, W1T 7DN UK
- Barts Heart Center, St Bartholomew’s Hospital, West Smithfield, London, EC1A 7BE UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
| | - Peter Gatehouse
- CMR Department, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - Kathryn E. Keenan
- National Institutes of Standards and Technology (NIST), Boulder, MS 818.03, 325 Broadway, Boulder, CO 80305-3337 USA
| | - Friso G. Heslinga
- Biomagnetics Group, School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 Australia
- NeuroImaging group, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE Enschede, Netherlands
| | - Ruediger Bruehl
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2 – 12, D-10587, Berlin, Germany
| | - Marcel Prothmann
- Cardiology, Charité, Medical Faculty of Humboldt-University Berlin ECRC and HELIOS Clinics, Berlin, Germany
| | - Martin J. Graves
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Richard J. Eames
- Department of Physics, Imperial College London, Prince Consort Rd, London, SW7 2BB UK
| | - Camilla Torlasco
- University of Milan-Bicocca, Piazza dell’Ateneo Nuovo 1, 20100 Milan, Italy
| | | | - Jacqueline Donovan
- Department of Clinical Biochemistry, Royal Brompton Hospital, Sydney Street, London, SW3 6NP UK
| | - Bernd Ittermann
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2 – 12, D-10587, Berlin, Germany
| | - Redha Boubertakh
- Cardiovascular Biomedical Research Unit, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Andrew Bathgate
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
| | - Celine Royet
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
| | - Wenjie Pang
- Resonance Health, 278 Stirling Highway, Claremont, WA 6010 Australia
| | - Reza Nezafat
- Department of Medicine (Cardiovascular Division) Beth Israel Deaconess Medical Center, Harvard Medical School, Cardiology East Campus, Room E/SH455, 330 Brookline Ave, Boston, MA 02215 USA
| | - Michael Salerno
- University of Virginia Health System, 1215 Lee St, PO Box 800158, Charlottesville, VA 22908 USA
| | - Peter Kellman
- National Heart, Lung, and Blood Institute, National Institutes of Health, 10 Center Drive, Building 10, Room B1D416, MSC1061, Bethesda, MD 20892-1061 USA
| | - James C. Moon
- NIHR University College London Hospitals Biomedical Research Center, Maple House Suite, Tottenham Court Road, London, W1T 7DN UK
- Barts Heart Center, St Bartholomew’s Hospital, West Smithfield, London, EC1A 7BE UK
- UCL Institute of Cardiovascular Science, University College London, Gower Street, London, WC1E 6BT UK
| |
Collapse
|
28
|
Captur G, Gatehouse P, Kellman P, Heslinga FG, Keenan K, Bruehl R, Prothmann M, Graves MJ, Chiribiri A, Ittermann B, Pang W, Nezafat R, Salerno M, Moon JC. A T1 and ECV phantom for global T1 mapping quality assurance: The T1 mapping and ECV standardisation in CMR (T1MES) program. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032466 DOI: 10.1186/1532-429x-18-s1-w14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
29
|
Hofman MB, Rodenburg MJ, Bloch KM, Werner B, Westenberg JJ, Valsangiacomo-Buechel E, Nijveldt R, Spruijt OA, Kilner PJ, van Rossum AC, Gatehouse P. In-vivo validation of interpolation-based phase offset correction in MR flow quantification: a multi-vendor, multi-center study. J Cardiovasc Magn Reson 2016. [PMCID: PMC5032564 DOI: 10.1186/1532-429x-18-s1-o88] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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
|
30
|
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]
|
31
|
Heng E, Kellman P, Gatzoulis MA, Moon J, Gatehouse P, Babu-Narayan SV. Quantifying right ventricular diffuse fibrosis in tetralogy of Fallot - a novel customised approach for the challenges of the right ventricle. Journal of Cardiovascular Magnetic Resonance 2016. [PMCID: PMC5032192 DOI: 10.1186/1532-429x-18-s1-o26] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
32
|
Vassiliou V, Heng EL, Sharma P, Nyktari E, Raphael CE, Chin CW, Drivas P, Smith GC, Symmonds K, Mathew GL, Wage R, Ali A, Greiser A, Alpendurada F, Dweck MR, Pennell DJ, Gatehouse P, Prasad SK. Reproducibility of T1 mapping 11-heart beat MOLLI Sequence. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328491 DOI: 10.1186/1532-429x-17-s1-w26] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
33
|
|
34
|
Raphael CE, Hsu LY, Greve AM, Cooper R, Gatehouse P, Wage R, Vassiliou V, Ali A, de Silva R, Stables RH, Di Mario C, Parker KH, Pennell DJ, Arai AE, Prasad SK. Wave intensity analysis and assessment of myocardial perfusion abnormalities in patients with hypertrophic cardiomyopathy. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328451 DOI: 10.1186/1532-429x-17-s1-q72] [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: 11/11/2022] Open
|
35
|
McGill LA, Scott AD, Ferreira P, Nielles-Vallespin S, Ismail TF, Kilner PJ, Gatehouse P, Prasad SK, Giannakidis A, Firmin D, Pennell DJ. Heterogeneity of diffusion tensor imaging measurements of fractional anisotropy and mean diffusivity in normal human hearts in vivo. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328820 DOI: 10.1186/1532-429x-17-s1-o1] [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
|
36
|
Wage R, Patel H, Smith GC, Keegan J, Gatehouse P, Vassiliou V, Heng EL, Hayward C, Rosen SD, Lyon A, Mohiaddin R, Prasad SK, Pennell DJ, Di Mario C. The utility of magnetic resonance imaging in a trial to assess the effect of renal denervation in heart failure with preserved ejection fraction. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328321 DOI: 10.1186/1532-429x-17-s1-t7] [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: 11/10/2022] Open
|
37
|
Vassiliou V, Heng EL, Donovan J, Greiser A, Babu-Narayan SV, Gatzoulis MA, Firmin D, Pennell DJ, Gatehouse P, Prasad SK. Longitudinal stability of gel T1 MRI Phantoms for quality assurance of T1 mapping. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328467 DOI: 10.1186/1532-429x-17-s1-w28] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
38
|
Heng EL, Kellman P, Gatzoulis MA, Moon J, Gatehouse P, Babu-Narayan SV. Pilot data of right ventricular myocardial T1 quantification by free-breathing fat-water separated dark blood saturation-recovery imaging. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328753 DOI: 10.1186/1532-429x-17-s1-q23] [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: 11/10/2022] Open
|
39
|
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.
Collapse
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
| |
Collapse
|
40
|
Simpson R, Keegan J, Gatehouse P, Hansen M, Firmin D. Spiral tissue phase velocity mapping in a breath-hold with non-cartesian SENSE. Magn Reson Med 2014; 72:659-68. [PMID: 24123135 PMCID: PMC3979503 DOI: 10.1002/mrm.24971] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/23/2013] [Accepted: 09/05/2013] [Indexed: 11/07/2022]
Abstract
PURPOSE Tissue phase velocity mapping (TPVM) is capable of reproducibly measuring regional myocardial velocities. However acquisition durations of navigator gated techniques are long and unpredictable while current breath-hold techniques have low temporal resolution. This study presents a spiral TPVM technique which acquires high resolution data within a clinically acceptable breath-hold duration. METHODS Ten healthy volunteers are scanned using a spiral sequence with temporal resolution of 24 ms and spatial resolution of 1.7 × 1.7 mm. Retrospective cardiac gating is used to acquire data over the entire cardiac cycle. The acquisition is accelerated by factors of 2 and 3 by use of non-Cartesian SENSE implemented on the Gadgetron GPU system resulting in breath-holds of 17 and 13 heartbeats, respectively. Systolic, early diastolic, and atrial systolic global and regional longitudinal, circumferential, and radial velocities are determined. RESULTS Global and regional velocities agree well with those previously reported. The two acceleration factors show no significant differences for any quantitative parameter and the results also closely match previously acquired higher spatial resolution navigator-gated data in the same subjects. CONCLUSION By using spiral trajectories and non-Cartesian SENSE high resolution, TPVM data can be acquired within a clinically acceptable breath-hold.
Collapse
Affiliation(s)
- R. Simpson
- NIHR Royal Brompton Cardiovascular Biomedical Research Unit, London, UK
- Imperial College, London
| | - J. Keegan
- NIHR Royal Brompton Cardiovascular Biomedical Research Unit, London, UK
- Imperial College, London
| | - P. Gatehouse
- NIHR Royal Brompton Cardiovascular Biomedical Research Unit, London, UK
| | - M. Hansen
- National Heart, Lung and Blood Institute, NIH, Bethesda, Maryland, USA
| | - D. Firmin
- NIHR Royal Brompton Cardiovascular Biomedical Research Unit, London, UK
- Imperial College, London
| |
Collapse
|
41
|
Scott AD, Ferreira PFADC, Nielles-Vallespin S, Gatehouse P, McGill LA, Kilner P, Pennell DJ, Firmin DN. Optimal diffusion weighting for in vivo cardiac diffusion tensor imaging. Magn Reson Med 2014; 74:420-30. [PMID: 25154715 DOI: 10.1002/mrm.25418] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 07/21/2014] [Accepted: 07/29/2014] [Indexed: 01/10/2023]
Abstract
PURPOSE To investigate the influence of the diffusion weighting on in vivo cardiac diffusion tensor imaging (cDTI) and obtain optimal parameters. METHODS Ten subjects were scanned using stimulated echo acquisition mode echo planar imaging with six b-values, from 50 to 950 s·mm(-2) , plus b = 15 s·mm(-2) reference. The relationship between b-value and both signal loss and signal-to-noise ratio measures was investigated. Mean diffusivity, fractional anisotropy, and helical angle maps were calculated using all possible b-value pairs to investigate the effects of diffusion weighting on the main and reference data. RESULTS Signal decay at low b-values was dominated by processes with high apparent diffusion coefficients, most likely microvascular perfusion. This effect could be avoided by diffusion weighting of the reference images. Parameter maps were improved with increased b-value until the diffusion-weighted signal approached the noise floor. For the protocol used in this study, b = 750 s·mm(-2) combined with 150 s·mm(-2) diffusion weighting of the reference images proved optimal. CONCLUSION Mean diffusivity, fractional anisotropy, and helical angle from cDTI are influenced by the b-value of the main and reference data. Using optimal values improves parameter maps and avoids microvascular perfusion effects. This optimized protocol should provide greater sensitivity to pathological changes in parameter maps.
Collapse
Affiliation(s)
- Andrew D Scott
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College, London, UK
| | - Pedro F A D C Ferreira
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College, London, UK
| | - Sonia Nielles-Vallespin
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Peter Gatehouse
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College, London, UK
| | - Laura-Ann McGill
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College, London, UK
| | - Philip Kilner
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College, London, UK
| | - Dudley J Pennell
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College, London, UK
| | - David N Firmin
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK.,National Heart and Lung Institute, Imperial College, London, UK
| |
Collapse
|
42
|
Ismail TF, Hsu LY, Greve AM, Gonçalves C, Jabbour A, Gulati A, Hewins B, Mistry N, Wage R, Roughton M, Ferreira PF, Gatehouse P, Firmin D, O’Hanlon R, Pennell DJ, Prasad SK, Arai AE. Coronary microvascular ischemia in hypertrophic cardiomyopathy - a pixel-wise quantitative cardiovascular magnetic resonance perfusion study. J Cardiovasc Magn Reson 2014; 16:49. [PMID: 25160568 PMCID: PMC4145339 DOI: 10.1186/s12968-014-0049-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [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: 11/17/2013] [Accepted: 06/20/2014] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Microvascular dysfunction in HCM has been associated with adverse clinical outcomes. Advances in quantitative cardiovascular magnetic resonance (CMR) perfusion imaging now allow myocardial blood flow to be quantified at the pixel level. We applied these techniques to investigate the spectrum of microvascular dysfunction in hypertrophic cardiomyopathy (HCM) and to explore its relationship with fibrosis and wall thickness. METHODS CMR perfusion imaging was undertaken during adenosine-induced hyperemia and again at rest in 35 patients together with late gadolinium enhancement (LGE) imaging. Myocardial blood flow (MBF) was quantified on a pixel-by-pixel basis from CMR perfusion images using a Fermi-constrained deconvolution algorithm. Regions-of-interest (ROI) in hypoperfused and hyperemic myocardium were identified from the MBF pixel maps. The myocardium was also divided into 16 AHA segments. RESULTS Resting MBF was significantly higher in the endocardium than in the epicardium (mean ± SD: 1.25 ± 0.35 ml/g/min versus 1.20 ± 0.35 ml/g/min, P<0.001), a pattern that reversed with stress (2.00 ± 0.76 ml/g/min versus 2.36 ± 0.83 ml/g/min, P<0.001). ROI analysis revealed 11 (31%) patients with stress MBF lower than resting values (1.05 ± 0.39 ml/g/min versus 1.22 ± 0.36 ml/g/min, P=0.021). There was a significant negative association between hyperemic MBF and wall thickness (β=-0.047 ml/g/min per mm, 95% CI: -0.057 to -0.038, P<0.001) and a significantly lower probability of fibrosis in a segment with increasing hyperemic MBF (odds ratio per ml/g/min: 0.086, 95% CI: 0.078 to 0.095, P=0.003). CONCLUSIONS Pixel-wise quantitative CMR perfusion imaging identifies a subgroup of patients with HCM that have localised severe microvascular dysfunction which may give rise to myocardial ischemia.
Collapse
Affiliation(s)
- Tevfik F Ismail
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
- Imperial College London, London, UK
| | - Li-Yueh Hsu
- Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Anders M Greve
- Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Carla Gonçalves
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
| | - Andrew Jabbour
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
| | - Ankur Gulati
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
| | - Benjamin Hewins
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
| | - Niraj Mistry
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
- Imperial College London, London, UK
| | - Ricardo Wage
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
| | | | - Pedro F Ferreira
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
- Imperial College London, London, UK
| | - Peter Gatehouse
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
- Imperial College London, London, UK
| | - David Firmin
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
- Imperial College London, London, UK
| | - Rory O’Hanlon
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
| | - Dudley J Pennell
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
- Imperial College London, London, UK
| | - Sanjay K Prasad
- Cardiovascular Magnetic Resonance and Cardiovascular Biomedical Research Units, Royal Brompton Hospital, London, UK
- Imperial College London, London, UK
| | - Andrew E Arai
- Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| |
Collapse
|
43
|
Nielles-Vallespin S, Mekkaoui C, Gatehouse P, Reese TG, Keegan J, Ferreira PF, Collins S, Speier P, Feiweier T, de Silva R, Jackowski MP, Pennell DJ, Sosnovik DE, Firmin D. Erratum to In vivo diffusion tensor MRI of the human heart: Reproducibility of breath-hold and navigator based approaches (Magn Reson Med 2013;70:454-465). Magn Reson Med 2014. [DOI: 10.1002/mrm.25237] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sonia Nielles-Vallespin
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
- Imperial College of Science; Technology and Medicine; London United Kingdom
| | - Choukri Mekkaoui
- Martinos Center for Biomedical Imaging; Massachusetts General Hospital, Harvard, Medical School; Boston Massachusetts USA
| | - Peter Gatehouse
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
- Imperial College of Science; Technology and Medicine; London United Kingdom
| | - Timothy G. Reese
- Martinos Center for Biomedical Imaging; Massachusetts General Hospital, Harvard, Medical School; Boston Massachusetts USA
| | - Jennifer Keegan
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
- Imperial College of Science; Technology and Medicine; London United Kingdom
| | - Pedro F. Ferreira
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
- Imperial College of Science; Technology and Medicine; London United Kingdom
| | - Steve Collins
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
| | - Peter Speier
- MR R&D, Siemens AG Healthcare Sector; Erlangen Germany
| | | | - Ranil de Silva
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
- Imperial College of Science; Technology and Medicine; London United Kingdom
| | - Marcel P. Jackowski
- Institute of Mathematics and Statistics; University of São Paulo; São Paulo Brazil
| | - Dudley J. Pennell
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
- Imperial College of Science; Technology and Medicine; London United Kingdom
| | - David E. Sosnovik
- Martinos Center for Biomedical Imaging; Massachusetts General Hospital, Harvard, Medical School; Boston Massachusetts USA
| | - David Firmin
- Cardiovascular MR Unit; Royal Brompton And Harefield NHS Foundation Trust; London United Kingdom
- Imperial College of Science; Technology and Medicine; London United Kingdom
| |
Collapse
|
44
|
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
|
45
|
Simpson R, Keegan J, Gatehouse P, Hansen M, Firmin D. Accelerating spiral tissue phase velocity mapping without affecting peak velocity measurements. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044467 DOI: 10.1186/1532-429x-16-s1-w31] [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: 11/17/2022] Open
|
46
|
Heng EL, Vassiliou V, Gatehouse P, Greiser A, Giri S, Donovan J, Babu-Narayan SV, Gatzoulis MA, Pennell DJ, Prasad SK, Firmin D. Temporal stability of gel relaxation-time phantoms for quality control of T1 and extracellular volume fraction measurements. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044048 DOI: 10.1186/1532-429x-16-s1-p60] [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: 11/17/2022] Open
|
47
|
Keegan J, Gatehouse P, Haldar S, Wage R, Babu-Narayan SV, Firmin D. Improved 3D late gadolinium enhancement (LGE) imaging with dynamic-TI in patients with persistent atrial fibrillation. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044963 DOI: 10.1186/1532-429x-16-s1-p6] [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: 11/29/2022] Open
|
48
|
Simpson R, Keegan J, Gatehouse P, Hansen M, Firmin D. Breath-hold spiral tissue phase velocity mapping (TPVM) with non-Cartesian SENSE. J Cardiovasc Magn Reson 2014. [PMCID: PMC4043792 DOI: 10.1186/1532-429x-16-s1-p40] [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: 11/17/2022] Open
|
49
|
Ali A, Hsu LY, Gulati A, Ismail T, Raphael CE, Vassiliou V, Chahal N, Krishnathansan K, Davendralingam N, Goncalves C, Wage R, Ferreira P, Baksi AJ, Gatehouse P, Firmin D, Pennell DJ, Kellman P, Arai AE, Prasad SK. The association between ECV and microcirculation perfusion abnormalities in non-ischemic dilated cardiomyopathy. J Cardiovasc Magn Reson 2014. [PMCID: PMC4044194 DOI: 10.1186/1532-429x-16-s1-o88] [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: 11/14/2022] Open
|
50
|
Nielles-Vallespin S, Mekkaoui C, Gatehouse P, Reese TG, Keegan J, Ferreira PF, Collins S, Speier P, Feiweier T, de Silva R, Jackowski MP, Pennell DJ, Sosnovik DE, Firmin D. In vivo diffusion tensor MRI of the human heart: reproducibility of breath-hold and navigator-based approaches. Magn Reson Med 2012; 70:454-65. [PMID: 23001828 DOI: 10.1002/mrm.24488] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [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: 02/24/2012] [Revised: 08/13/2012] [Accepted: 08/15/2012] [Indexed: 11/11/2022]
Abstract
The aim of this study was to implement a quantitative in vivo cardiac diffusion tensor imaging (DTI) technique that was robust, reproducible, and feasible to perform in patients with cardiovascular disease. A stimulated-echo single-shot echo-planar imaging (EPI) sequence with zonal excitation and parallel imaging was implemented, together with a novel modification of the prospective navigator (NAV) technique combined with a biofeedback mechanism. Ten volunteers were scanned on two different days, each time with both multiple breath-hold (MBH) and NAV multislice protocols. Fractional anisotropy (FA), mean diffusivity (MD), and helix angle (HA) fiber maps were created. Comparison of initial and repeat scans showed good reproducibility for both MBH and NAV techniques for FA (P > 0.22), MD (P > 0.15), and HA (P > 0.28). Comparison of MBH and NAV FA (FAMBHday1 = 0.60 ± 0.04, FANAVday1 = 0.60 ± 0.03, P = 0.57) and MD (MDMBHday1 = 0.8 ± 0.2 × 10(-3) mm(2) /s, MDNAVday1 = 0.9 ± 0.2 × 10(-3) mm(2) /s, P = 0.07) values showed no significant differences, while HA values (HAMBHday1Endo = 22 ± 10°, HAMBHday1Mid-Endo = 20 ± 6°, HAMBHday1Mid-Epi = -1 ± 6°, HAMBHday1Epi = -17 ± 6°, HANAVday1Endo = 7 ± 7°, HANAVday1Mid-Endo = 13 ± 8°, HANAVday1Mid-Epi = -2 ± 7°, HANAVday1Epi = -14 ± 6°) were significantly different. The scan duration was 20% longer with the NAV approach. Currently, the MBH approach is the more robust in normal volunteers. While the NAV technique still requires resolution of some bulk motion sensitivity issues, these preliminary experiments show its potential for in vivo clinical cardiac diffusion tensor imaging and for delivering high-resolution in vivo 3D DTI tractography of the heart.
Collapse
|