Single-Breath-Hold Whole-heart Unenhanced Coronary MRA Using Multi-shot Gradient Echo EPI at 3T: Comparison with Free-breathing Turbo-field-echo Coronary MRA on Healthy Volunteers

Background Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis. Purpose To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers. Material and Methods The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s. Results For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique’s 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased. Conclusion Single breath-hold black-blood FSE sequence has better scan–rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.

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Measurement of T1 Mapping in Patients With Cardiac Devices: Off-Resonance Error Extends Beyond Visual Artifact but Can Be Quantified and Corrected

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.631366 ◽

2021 ◽

Vol 8 ◽

Author(s):

Anish N. Bhuva ◽

Thomas A. Treibel ◽

Andreas Seraphim ◽

Paul Scully ◽

Kristopher D. Knott ◽

...

Keyword(s):

Healthy Volunteers ◽

Pulse Sequence ◽

Resonance Field ◽

Breath Hold ◽

Implantable Cardioverter Defibrillators ◽

Single Breath ◽

Single Breath Hold ◽

Cardiac Implantable Electronic Devices ◽

Cardiac Devices ◽

Cardiovascular Implants

Background: Measurement of myocardial T1 is increasingly incorporated into standard cardiovascular magnetic resonance (CMR) protocols, however accuracy may be reduced in patients with metallic cardiovascular implants. Measurement is feasible in segments free from visual artifact, but there may still be off-resonance induced error.Aim: To quantify off-resonance induced T1 error in patients with metallic cardiovascular implants, and validate a method for error correction for a conventional MOLLI pulse sequence.Methods: Twenty-four patients with cardiac implantable electronic devices (CIEDs: 46% permanent pacemakers, PPMs; 33% implantable loop recorders, ILRs; and 21% implantable cardioverter-defibrillators, ICDs); and 31 patients with aortic valve replacement (AVR) (45% metallic) were studied. Paired mid-myocardial short-axis MOLLI and single breath-hold off-resonance field maps were acquired at 1.5 T. T1 values were measured by AHA segment, and segments with visual artifact were excluded. T1 correction was applied using a published relationship between off-resonance and T1. The accuracy of the correction was assessed in 10 healthy volunteers by measuring T1 before and after external placement of an ICD generator next to the chest to generate off-resonance.Results: T1 values in healthy volunteers with an ICD were underestimated compared to without (967 ± 52 vs. 997 ± 26 ms respectively, p = 0.0001), but were similar after correction (p = 0.57, residual difference 2 ± 27 ms). Artifact was visible in 4 ± 12, 42 ± 31, and 53 ± 27% of AHA segments in patients with ILRs, PPMs, and ICDs, respectively. In segments without artifact, T1 was underestimated by 63 ms (interquartile range: 7–143) per patient. The greatest error for patients with ILRs, PPMs and ICDs were 79, 146, and 191 ms, respectively. The presence of an AVR did not generate T1 error.Conclusion: Even when there is no visual artifact, there is error in T1 in patients with CIEDs, but not AVRs. Off-resonance field map acquisition can detect error in measured T1, and a correction can be applied to quantify T1 MOLLI accurately.

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Whole-Heart Single Breath-Hold Cardiac Cine: A Robust Motion-Compensated Compressed Sensing Reconstruction Method

Reconstruction, Segmentation, and Analysis of Medical Images - Lecture Notes in Computer Science ◽

10.1007/978-3-319-52280-7_6 ◽

2017 ◽

pp. 58-69 ◽

Cited By ~ 1

Author(s):

Javier Royuela-del-Val ◽

Muhammad Usman ◽

Lucilio Cordero-Grande ◽

Marcos Martin-Fernandez ◽

Federico Simmross-Wattenberg ◽

...

Keyword(s):

Compressed Sensing ◽

Breath Hold ◽

Reconstruction Method ◽

Single Breath ◽

Single Breath Hold ◽

Cardiac Cine ◽

Whole Heart

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Safely achieving single prolonged breath-holds of > 5 minutes for radiotherapy in the prone, front crawl position

British Journal of Radiology ◽

10.1259/bjr.20210079 ◽

2021 ◽

pp. 20210079

Author(s):

MJ Parkes ◽

Wilfried De Neve ◽

Vincent Vakaet ◽

Geoffrey Heyes ◽

Timothy Jackson ◽

...

Keyword(s):

Breast Cancer ◽

Carbon Dioxide ◽

Healthy Volunteers ◽

Breath Hold ◽

Surface Markers ◽

Front Crawl ◽

Single Breath ◽

Single Breath Hold ◽

Breast Cancer Radiotherapy ◽

Short Breath

Objective: Breast cancer radiotherapy is increasingly delivered supine with multiple, short breath-holds. There may be heart and lung sparing advantages for locoregional breast cancer of both prone treatment and in a single breath-hold. We test here whether single prolonged breath-holds are possible in the prone, front crawl position. Methods: 19 healthy volunteers were trained to deliver supine, single prolonged breath-holds with pre-oxygenation and hypocapnia. We tested whether all could achieve the same durations in the prone, front crawl position. Results: 19 healthy volunteers achieved supine, single prolonged breath-holds for mean of 6.2 ± 0.3 min. All were able to hold safely for the same duration while prone (6.1 ± 0.2 min ns. by paired ANOVA). With prone, the increased weight on the chest did not impede chest inflation, nor the ability to hold air in the chest. Thus, the rate of chest deflation (mean anteroposterior deflation movement of three craniocaudally arranged surface markers on the spinal cord) was the same (1.2 ± 0.2, 2.0 ± 0.4 and 1.2 ± 0.4 mm/min) as found previously during supine prolonged breath-holds. No leakage of carbon dioxide or air was detectable into the facemask. Conclusion: Single prolonged (>5 min) breath-holds are equally possible in the prone, front crawl position. Advances in knowledge: Prolonged breath-holds in the front crawl position are possible and have the same durations as in the supine position. Such training would therefore be feasible for some patients with breast cancer requiring loco-regional irradiation. It would have obvious advantages for hypofractionation.

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