Cardiac <scp>MRI</scp> at Low Field Strengths

Campbell‐Washburn, Adrienne E.; Varghese, Juliet; Nayak, Krishna S.; Ramasawmy, Rajiv; Simonetti, Orlando P.

doi:10.1002/jmri.28890

Cited by 9 publications

(3 citation statements)

References 140 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lower field, open MRI scanners have been available for some time, offering an alternative that can accommodate patients with severe obesity and/or claustrophobia. While cardiac MRI has been demonstrated on these systems [ 32 , 33 ], an open magnet configuration can require compromises in overall system performance. The recent introduction of low-field MRI scanners with conventional magnet design but larger bore diameter and higher table weight limits may help expand MRI access to patients with severe obesity [ 34 ].…”

Section: Discussionmentioning

confidence: 99%

The impact of severe obesity on image quality and ventricular function assessment in echocardiography and cardiac MRI

Goyal,

Crabtree,

Lee

et al. 2024

Int J Cardiovasc Imaging

Self Cite

View full text Add to dashboard Cite

This study sought to evaluate the impact of severe obesity on image quality and ventricular function assessment in cardiovascular magnetic resonance (MRI) and trans-thoracic echocardiography (TTE). We studied 100 consecutive patients who underwent clinically indicated cardiac MRI and TTE studies within 12 months between July 2017 and December 2020; 50 (28 females and 22 males; 54.5 ± 18.7 years) with normal body mass index (BMI) (18.5–25 kg/m2) and 50 (21 females and 29 males; 47.2 ± 13.3 years) with severe obesity (BMI ≥ 40 kg/m2). MRI and TTE image quality scores were compared within and across cohorts using a linear mixed model. Categorical left (LVF) and right (RVF) ventricular function were compared using Cohens Kappa statistic. Mean BMI for normal weight and obese cohorts were 22.2 ± 1.7 kg/m2 and 50.3 ± 5.9 kg/m2, respectively. Out of a possible 93 points, mean MRI image quality score was 91.5 ± 2.5 for patients with normal BMI, and 88.4 ± 5.5 for patients with severe obesity; least square (LS) mean difference 3.1, p = 0.460. TTE scores were 64.2 ± 13.6 for patients with normal BMI and 46.0 ± 12.9 for patients with severe obesity, LS mean difference 18.2, p < 0.001. Ventricular function agreement between modalities was worse in the obese cohort for both LVF (72% vs 80% agreement; kappa 0.53 vs 0.70, obese vs. normal BMI), and RVF (58% vs 72% agreement, kappa 0.18 vs 0.34, obese vs. normal BMI). Severe obesity had limited impact on cardiac MRI image quality, while obesity significantly degraded TTE image quality and ventricular function agreement with MRI.

show abstract

Section: Discussionmentioning

confidence: 99%

The impact of severe obesity on image quality and ventricular function assessment in echocardiography and cardiac MRI

Goyal,

Crabtree,

Lee

et al. 2024

Int J Cardiovasc Imaging

Self Cite

View full text Add to dashboard Cite

show abstract

“…5,6 Another important factor affecting relaxation parameters is the magnetic field strength. 5,[7][8][9] Most of the current myocardial parametric mapping sequences have been developed and validated at a field strength of 1.5 T or 3 T, [10][11][12][13] as these are the most common field strengths in clinical use. With the renewed interest in cardiac imaging at lower-field-strength (0.55T) MRI systems, there is a desire to develop mapping techniques at this field strength.…”

Section: Introductionmentioning

confidence: 99%

“…First, the shorter T 1 and longer T 2 relaxation time require specific optimization in sequence design. 7,9 Second, lower field strength results in an inherently low SNR. 15 Third, the limited gradient performance of current commercial 0.55T MRI scanners leads to longer TRs and TEs, which reduces the scan efficiency, increases the scan time, and restricts the spatial and temporal resolution.…”

Section: Introductionmentioning

confidence: 99%

Free‐breathing 3D whole‐heart joint T₁/T₂ mapping and water/fat imaging at 0.55 T

Si,

Crabb,

Kunze

et al. 2024

Magnetic Resonance in Med

View full text Add to dashboard Cite

PurposeTo develop and validate a highly efficient motion compensated free‐breathing isotropic resolution 3D whole‐heart joint T1/T2 mapping sequence with anatomical water/fat imaging at 0.55 T.MethodsThe proposed sequence takes advantage of shorter T1 at 0.55 T to acquire three interleaved water/fat volumes with inversion‐recovery preparation, no preparation, and T2 preparation, respectively. Image navigators were used to facilitate nonrigid motion‐compensated image reconstruction. T1 and T2 maps were jointly calculated by a dictionary matching method. Validations were performed with simulation, phantom, and in vivo experiments on 10 healthy volunteers and 1 patient. The performance of the proposed sequence was compared with conventional 2D mapping sequences including modified Look‐Locker inversion recovery and T2‐prepared balanced steady‐SSFP sequence.ResultsThe proposed sequence has a good T1 and T2 encoding sensitivity in simulation, and excellent agreement with spin‐echo reference T1 and T2 values was observed in a standardized T1/T2 phantom (R2 = 0.99). In vivo experiments provided good‐quality co‐registered 3D whole‐heart T1 and T2 maps with 2‐mm isotropic resolution in a short scan time of about 7 min. For healthy volunteers, left‐ventricle T1 mean and SD measured by the proposed sequence were both comparable with those of modified Look‐Locker inversion recovery (640 ± 35 vs. 630 ± 25 ms [p = 0.44] and 49.9 ± 9.3 vs. 54.4 ± 20.5 ms [p = 0.42]), whereas left‐ventricle T2 mean and SD measured by the proposed sequence were both slightly lower than those of T2‐prepared balanced SSFP (53.8 ± 5.5 vs. 58.6 ± 3.3 ms [p < 0.01] and 5.2 ± 0.9 vs. 6.1 ± 0.8 ms [p = 0.03]). Myocardial T1 and T2 in the patient measured by the proposed sequence were in good agreement with conventional 2D sequences and late gadolinium enhancement.ConclusionThe proposed sequence simultaneously acquires 3D whole‐heart T1 and T2 mapping with anatomical water/fat imaging at 0.55 T in a fast and efficient 7‐min scan. Further investigation in patients with cardiovascular disease is now warranted.

show abstract

Exercise MR of Skeletal Muscles, the Heart, and the Brain

Hooijmans,

Jeneson,

Jørstad

et al. 2024

Magnetic Resonance Imaging

View full text Add to dashboard Cite

Magnetic resonance (MR) imaging (MRI) is routinely used to evaluate organ morphology and pathology in the human body at rest or in combination with pharmacological stress as an exercise surrogate. With MR during actual physical exercise, we can assess functional characteristics of tissues and organs under real‐life stress conditions. This is particularly relevant in patients with limited exercise capacity or exercise intolerance, and where complaints typically present only during physical activity, such as in neuromuscular disorders, inherited metabolic diseases, and heart failure. This review describes practical and physiological aspects of exercise MR of skeletal muscles, the heart, and the brain. The acute effects of physical exercise on these organs are addressed in the light of various dynamic quantitative MR readouts, including phosphorus‐31 MR spectroscopy (31P‐MRS) of tissue energy metabolism, phase‐contrast MRI of blood flow and muscle contraction, real‐time cine MRI of cardiac performance, and arterial spin labeling MRI of muscle and brain perfusion. Exercise MR will help advancing our understanding of underlying mechanisms that contribute to exercise intolerance, which often proceed structural and anatomical changes in disease. Its potential to detect disease‐driven alterations in organ function, perfusion, and metabolism under physiological stress renders exercise MR stress testing a powerful noninvasive imaging modality to aid in disease diagnosis and risk stratification. Although not yet integrated in most clinical workflows, and while some applications still require thorough validation, exercise MR has established itself as a comprehensive and versatile modality for characterizing physiology in health and disease in a noninvasive and quantitative way.Evidence Level5Technical EfficacyStage 1

show abstract

Cardiac MRI at Low Field Strengths

Cited by 9 publications

References 140 publications

The impact of severe obesity on image quality and ventricular function assessment in echocardiography and cardiac MRI

The impact of severe obesity on image quality and ventricular function assessment in echocardiography and cardiac MRI

Free‐breathing 3D whole‐heart joint T₁/T₂ mapping and water/fat imaging at 0.55 T

Exercise MR of Skeletal Muscles, the Heart, and the Brain

Contact Info

Product

Resources

About

Cardiac MRI at Low Field Strengths

Cited by 9 publications

References 140 publications

The impact of severe obesity on image quality and ventricular function assessment in echocardiography and cardiac MRI

The impact of severe obesity on image quality and ventricular function assessment in echocardiography and cardiac MRI

Free‐breathing 3D whole‐heart joint T1/T2 mapping and water/fat imaging at 0.55 T

Exercise MR of Skeletal Muscles, the Heart, and the Brain

Contact Info

Product

Resources

About

Free‐breathing 3D whole‐heart joint T₁/T₂ mapping and water/fat imaging at 0.55 T