scholarly journals A single breath-hold multiecho T2* cardiovascular magnetic resonance technique for diagnosis of myocardial iron overload

2003 ◽  
Vol 18 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Mark Westwood ◽  
Lisa J. Anderson ◽  
David N. Firmin ◽  
Peter D. Gatehouse ◽  
Clare C. Charrier ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Iron Overload ◽  
Breath Hold ◽  
Myocardial Iron ◽  
Resonance Technique ◽  
Single Breath ◽  
Single Breath Hold ◽  
Magnetic Resonance Technique ◽  
Cardiovascular Magnetic Resonance Technique

Precision of Multi-Echo CMR for Myocardial Iron Overload Evaluation Is Dependent From MR Sequence Design

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5169-5169
Author(s):  
Antonella Meloni ◽  
incenzo Positano ◽  
Alessia Pepe ◽  
Dell'Amico Maria Chiara ◽  
Luca Menichetti ◽  
...  
Keyword(s):  
Iron Overload ◽  
Conflicts Of Interest ◽  
Iron Concentration ◽  
Breath Hold ◽  
Myocardial Iron ◽  
Single Breath ◽  
Single Breath Hold ◽  
Values Assessment ◽  
Value Determination ◽  
Almost All

Abstract Abstract 5169 Introduction. T2* multiecho cardiovascular magnetic resonance (CMR) is largely used to assess iron overload in heart because of the established inverse relationship between the T2* value and the iron concentration in tissues (Wood JC et al, Hemoglobin 2008). The decay of CMR signal is sampled at several echo times (TEs) and the T2* is inferred by fitting the decay curve to an appropriate model (Positano V et al, NMR in Biomed 2007). Our aim was to quantify the reliance on TEs of the expected error in T2* value determination. Methods. The Cramer-Rao lower bounds theory (CRLB) was used. CRLB provide a fundamental limit to the accuracy in determination of the T2* value from experimental data in dependence of SNR at signal samples. CRLB were evaluated for a commonly used multi-echo sequence with the first TE equal to the minimum achievable (1.4-2 ms), ΔTE of about 2.3 ms to minimize the fat-water interface artifacts, 10 echoes to assure acquisition in a single breath-hold. Results. Percent error in T2* values assessment was lower than 10% in the range of clinical interest, with the exception of very low T2* values. Precision in measurement of low T2* values is strongly dependent on the value of the first TE, that is limited by the used scanner. T2* values greater than 1.8 ms and 1.5 ms can be assessed with an error below 20% using a first TE of 2 ms and 1.5 ms, respectively (see Figure). Conclusions. T2* multiecho sequences used in clinical practice assure an acceptable precision for T2* values ≥ 2 ms, depending from the used hardware. This limit includes almost all patients with hemochromatosis or hemosiderosis in country where the patients can be well managed. For patients with very high myocardial iron overload sequences with lower minimum echo time and/or lower echoes interval may be useful. Disclosures: No relevant conflicts of interest to declare.

Inter-Site Validation of a Single Breath Hold T2* MR Technique for Heart and Liver Iron Measurement.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3830-3830 ◽  
Author(s):  
Paul Kirk ◽  
Lisa J. Anderson ◽  
Mark A. Tanner ◽  
Renzo Galanello ◽  
Gildo Matta ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Breath Hold ◽  
Iron Loading ◽  
Myocardial Iron ◽  
Thalassaemia Major ◽  
Liver Iron ◽  
Single Breath ◽  
Single Breath Hold ◽  
Average Coefficient ◽  
Siemens Sonata

Abstract Background Approximately 60,000 people are born with thalassaemia major every year. The average life expectancy of thalassaemia major patients is 35 years due to iron overload Cardiomyopathy. The cardiomyopathy is reversible when treated early, but once heart failure is established it is often rapidly progressive, and unresponsive to treatment. The single breath hold (SBH) T2* technique has been validated as the most robust and reproducible non-invasive measurement of myocardial and iron load. Our aim in this study was to validate the transferability and reproducibility of this technique in different scanners worldwide. Methods We aim to compare the reproducibility in six different sites worldwide as part of an NIH funded grant (R01-DK66084-01). So far, two of these sites have been validated: Singapore (Siemens Sonata, 1.5T scanner) and Cagliari, Italy (GE Signa, 1.5 T scanner). At both validation sites, 10 patients were scanned for heart and liver T2*, and scans were repeated for interstudy reproducibility. All patients then flew to London to be rescanned on our reference Siemens Sonata scanner. Results Of the 20 patients scanned, 70% had myocardial iron loading (T2* <20ms) and in 10% the myocardial iron loading was severe. Liver iron loading was present in 65% of patients and in 30% this was severe. The coefficient of variation (COV) for the heart T2* measurements between the local sites and London was 5.9% and 4.9% yielding an average coefficient of variation across both sites of 5.4% (figure 1). The coefficient of variation (COV) for the liver T2* measurements between the local sites and London was 11.3% and 3.9% yielding an average coefficient of variation across both sites of 7.6% (figure 2). There was no significant correlation between liver and myocardial loading. Conclusion These are the first data demonstrating the transferability of the SBH T2* technique and the clinical validation from the 2 collaborating centers were excellent for both heart and liver measurements. Further MR sites confirmed for validation include Children’s Hospital of Philadelphia (USA); Ramathibodi Hospital, Bangkok (Thailand); and Chinese University Hong Kong. Figure 1 Figure 1. Figure 2 Figure 2.

A Cross-Sectional MRI T2* Study of Pancreatic and Pituitary Hemosiderosis in 180 Thalassemia Major Patients in Hong Kong.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2771-2771
Author(s):  
Wing Y. Au ◽  
Wynnie Lam ◽  
Winnie Chu ◽  
Hui-leung Yuen ◽  
S.C. Ling ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Iron Overload ◽  
Thalassemia Major ◽  
Carrier State ◽  
Breath Hold ◽  
Cross Sectional ◽  
Single Breath ◽  
Single Breath Hold ◽  
Organ Specific ◽  
Magnetic Resonance Imaging Mri

Abstract Background: The use of magnetic resonance imaging (MRI) for organ specific iron assessment has allowed better tailoring of chelation therapy. Since endocrine failure is common in thalassemia major (TM) patients, we explored the utility of rapid T2* MRI assessment of hemosiderosis in the pancreas and pituitary. The results were correlated with standard T2* heart and liver MRI assessments and clinical data. Material and methods: A total of 180 TM patients (M:F = 91:89, median age, range 12–48) were scanned on a 1.5 T scanner. (Sonata, Siemens Medical, Erlanger, Germany). T2* myocardium was assessed by a cardiac gated single breath hold 8-echo sequence (CMRtools; London, UK). The T2* liver, pancreas and pituitary were performed by a breath hold 20-echo sequence. Subcutaneous deferoxamine was used for chelation, except for addition of deferiprone in 24 cases for 1 year. Results: There was a high incidence of hemosiderosis of heart (severe T2*<12ms: 34%, mild-moderate <20ms, 15%) and liver (severe T2*<1.4ms, 14% mild-moderate <6.3ms, 63%). Iron overload above normal control was commonly found in the pancreas (T2*<23ms, 84%) and pituitary (T2*<5.9ms, 24%). Pancreatic T2* correlated with pituitary T2* (p=0.007, r=0.2), cardiac T2*(p<0.001, r=0.33), liver T2* (p<0.001, r=0.35), ferritin (p=0.004, r=−0.19) and age (p=0.033, r=0.16). Similarly pituitary T2* related to cardiac T2* (p<0.001, r=0.36) and liver T2* (p=0.026, r=0.17). On multivariate analysis, however, pancreatic T2* related to both heart T2* (p<0.001) and liver T2* (p=0.001), while pituitary T2* only related to heart T2* (p<0.001). Documented complications amongst the cases included heart failure (ejection fraction EF<55%, n=28, 16%), hypogonadism (n=84,47%), diabetes mellitus (n=44, 25%), hypoparathyroidism (n=16, 9%) and hypothyroidism (n=36, 20%), with hepatitis B and C carrier state in 2% and 25% respectively. On univariate and multivariate analysis, all 4 endocrine failures correlated with only cardiac T2* results (all p<0.001) and age (all p<0.001), but not with pituitary or pancreatic T2* results. The EF correlated with T2* of pituitary, pancreas and heart, but only MRI heart T2* correlation remained significant on multivariate analysis. Conclusions: MRI pituitary and pancreatic evaluation is viable in a cohort of poorly chelated Chinese thalassemia major patients on subcutaneous deferoxamine treatment. However, an abnormal cardiac T2* result is a good surrogate for endocrine iron overload and appeared more relevant in predicting endocrine complications.

scholarly journals Come eseguire lo studio cardiaco T2 star pesata di risonanza magnetica per gli accumuli di ferro nella talassemia

2020 ◽  
pp. 36-39
Author(s):  
Martini Alberto ◽  
Morelli Giovanni ◽  
Nappa Elena ◽  
Notorio Maurizio
Keyword(s):  
Iron Overload ◽  
Risk Group ◽  
Risonanza Magnetica ◽  
Middle Part ◽  
Mediterranean Coast ◽  
High Risk Group ◽  
Breath Hold ◽  
Single Breath ◽  
Single Breath Hold ◽  
T2 Mri

The aim of the study is to show how to execute a cardiac T2* MRI assessment correctly in patients who suffer from iron overload in vital organs, particularly in the heart. The main cause of iron overload is Thalassemia, the disease which is widely spread in the Southern and Middle part of Italy, as well as the Mediterranean coast. Researchers have demonstrated that patients who suffer from thalassemia might have an excessive and toxic iron overload which could lead to heart failure and death. Thanks to the T2*single breath-hold multi-echoes sequence, using a dedicated software, the patients’ myocardial iron deposition can be classified into three groups: T2* MRI < 10 ms ( high risk group) T2* MRI =10-20 ms ( medium-risk group) T2* MRI > 20 ms (low-risk group) This measure called “saturation time”(expressed in 1/1000 sec.), also allows physicians to customize medical treatment for every patient, same as a good tailor does to make a new dress fits well on every single client. However, to obtain precise and reliable results, radiographers first and radiologists afterwards, must respect every single technical parameter in MR techniques

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