A feasible and automatic free tool for T1 and ECV mapping

Altabella, Luisa; Borrazzo, Cristian; Carnì, Marco; Galea, Nicola; Francone, Marco; Fiorelli, Andrea; Castro, Elisabetta Di; Catalano, Carlo; Carbone, Iacopo

doi:10.1016/j.ejmp.2016.12.002

Cited by 18 publications

(21 citation statements)

References 20 publications

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“…(1) can equally well be employed to calculate ECV pixel-wise instead of ROI-wise and to generate ECV maps. The reliability of pixel ECV values crucially depends, however, on an adequate registration of native and post-contrast T1 maps [30,31]. The quotient of differences of T1 relaxation rates (i.e., reciprocal T1 times) in Eq.…”

Section: Post-contrast T1 and Ecv Mappingmentioning

confidence: 99%

Cardiac magnetic resonance T1 mapping. Part 1: Aspects of acquisition and evaluation

Reiter

Kräuter

et al. 2018

European Journal of Radiology

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While an enormous number of studies have documented pathological alterations of the myocardial native longitudinal relaxation time (T1) and the fraction of the extracellular myocardial volume (ECV), it has also become clear that continuously evolving T1 mapping sequence, acquisition and evaluation techniques have a substantial impact on quantitative results, making the translation of reported findings into routine clinical use particularly challenging. To provide a basis for the discussion of pathological myocardial T1 and ECV alterations, the present review aims to summarize the methodological aspects of myocardial T1 mapping along with technical and physiological factors influencing results and normal ranges of myocardial native T1 and ECV reported across studies. 2. Sequences and protocols Numerous techniques have been introduced for the generation of cardiac T1 maps [11-22], each of which possesses specific advantages and disadvantages with respect to acquisition time, spatial resolution, accuracy (systematic bias of estimated T1 compared to true T1), and

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Section: Post-contrast T1 and Ecv Mappingmentioning

confidence: 99%

Cardiac magnetic resonance T1 mapping. Part 1: Aspects of acquisition and evaluation

Reiter

Kräuter

et al. 2018

European Journal of Radiology

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“…Another way to avoid this bias would be if ECV calculations could be performed without the need for blood sampling. It has recently been proposed that T1 mapping can be used to determine a synthetic Hct derived from the longitudinal relaxation rate of blood [ 15 , 16 ]. Even though they showed a significant correlation (r 2 = 0.51) between longitudinal relaxation rate of the blood and Hct measured from venous blood, there may be significant difference in actual ECV and synthetic ECV for individual patients, specifically pediatric patients and young adults [ 17 ], affecting the ability to detect relatively small differences in ECV between normal and diffuse disease or treated vs non-treated subjects.…”

Section: Discussionmentioning

confidence: 99%

Importance of standardizing timing of hematocrit measurement when using cardiovascular magnetic resonance to calculate myocardial extracellular volume (ECV) based on pre- and post-contrast T1 mapping

Engblom

Kanski

Kopic

et al. 2018

Journal of Cardiovascular Magnetic Resonance

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BackgroundCardiovascular magnetic resonance (CMR) can be used to calculate myocardial extracellular volume fraction (ECV) by relating the longitudinal relaxation rate in blood and myocardium before and after contrast-injection to hematocrit (Hct) in blood. Hematocrit is known to vary with body posture, which could affect the calculations of ECV.The aim of this study was to test the hypothesis that there is a significant increase in calculated ECV values if the Hct is sampled after the CMR examination in supine position compared to when the patient arrives at the MR department.MethodsForty-three consecutive patients including various pathologies as well as normal findings were included in the study. Venous blood samples were drawn upon arrival to the MR department and directly after the examination with the patient remaining in supine position. A Modified Look-Locker Inversion recovery (MOLLI) protocol was used to acquire mid-ventricular short-axis images before and after contrast injection from which motion-corrected T1 maps were derived and ECV was calculated.ResultsHematocrit decreased from 44.0 ± 3.7% before to 40.6 ± 4.0% after the CMR examination (p < 0.001). This resulted in a change in calculated ECV from 24.7 ± 3.8% before to 26.2 ± 4.2% after the CMR examination (p < 0.001). All patients decreased in Hct after the CMR examination compared to before except for two patients whose Hct remained the same.ConclusionVariability in CMR-derived myocardial ECV can be reduced by standardizing the timing of Hct measurement relative to the CMR examination. Thus, a standardized acquisition of blood sample for Hct after the CMR examination, when the patient is still in supine position, would increase the precision of ECV measurements.

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“…ECM expansion has been linked to electrical, mechanical and vasomotor dysfunctions, cardiac brosis and, eventually, increased mortality (2, 3). Contrast enhanced Cardiac Computed Tomography (CCT) and Cardiovascular Magnetic Resonance (CMR) use extracellular extravascular contrast agents to non-invasively quantify the myocardial Extra-Cellular Volume (ECV) (3)(4)(5)(6). In particular, CCT is increasingly used in experimental and clinical setting, due to its opportunity to assess lots of cardiac features other than ECV and brosis (such as coronary anatomy, calci cation etc) in a very shorter time and with a higher spatial resolution than MRI (4,5).…”

Section: Introductionmentioning

confidence: 99%

Unexpected increase of myocardial extracellular volume fraction in low cardiovascular risk HIV patients

Borrazzo

d’Ettorre²,

Ceccarelli³

et al. 2020

Preprint

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Background: People living with HIV (PLWH) are prone to develop sub-clinical Cardiovascular (CV) disease, despite the effectiveness of combined Antiretroviral Therapy (cART). Algorithms developed to predict CV risk in the general population could be inaccurate when applied to PLWH. Myocardial Extra-Cellular Matrix (ECM) expansion, measured by computed tomography, has been associated with an increased CV vulnerability in HIV-negative population. Measurement of Myocardial Extra-Cellular Volume (ECV) by computed tomography or magnetic resonance, is considered a useful surrogate for clinical evaluation of ECM expansion. In the present study, we aimed to determine the extent of cardiovascular involvement in asymptomatic HIV-infected patients with the use of a comprehensive cardiac computed tomography (CCT) approach.Materials and methods: In the present study, ECV in low atherosclerotic CV risk PLWH was compared with ECV of age and gender matched HIV- individuals. 53 asymptomatic HIV+ individuals (45 males, age 48 (42.5-48) years) on effective cART (CD4+ cell count: 450 cells/μL (IQR: 328-750); plasma HIV RNA: <37 copies/ml in all subjects) and 18 age and gender matched controls (14 males, age 55 (44.5-56) years) were retrospectively enrolled. All participants underwent CCT protocol to obtain native and postcontrast Hounsfield unit values of blood and myocardium, ECM was calculated accordingly.Results: The ECV was significantly higher in HIV+ patients than in the control group (ECV: 31% (IQR: 28%-31%) vs 27.4% (IQR: 25%-28%), p<0.001). The duration of cART (standardized β=0.56 (0.33-0.95), p=0.014) and the years of exposure to HIV infection (standardized β=0.53 (0.4-0.92), p<0.001), were positively and strongly associated with ECV values. Differences in ECV (p<0.001) were also observed regarding the duration of cART exposure (<5 years, 5-10 years and >10 years). Moreover, ECV was independently associated with age of participants (standardized β = 0.42 (0.33-0.89), p=0.084).Conclusions: HIV infection and exposure to antiretrovirals play a detrimental role on ECV expansion. An increase in ECV indicates ECM expansion, which has been associated to a higher CV risk in the general population. The non-invasive evaluation of ECM trough ECV could represent an important tool to further understand the relationship between HIV infection, cardiac pathophysiology and the increased CV risk observed in PLWH.

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A feasible and automatic free tool for T1 and ECV mapping

Cited by 18 publications

References 20 publications

Cardiac magnetic resonance T1 mapping. Part 1: Aspects of acquisition and evaluation

Cardiac magnetic resonance T1 mapping. Part 1: Aspects of acquisition and evaluation

Importance of standardizing timing of hematocrit measurement when using cardiovascular magnetic resonance to calculate myocardial extracellular volume (ECV) based on pre- and post-contrast T1 mapping

Unexpected increase of myocardial extracellular volume fraction in low cardiovascular risk HIV patients

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