T1 mapping of the myocardium: intra-individual assessment of post-contrast T1 time evolution and extracellular volume fraction at 3T for Gd-DTPA and Gd-BOPTA

• Published in: Journal of cardiovascular magnetic resonance Vol. 14; no. 1; pp. 27 - 26
• Main Authors: Kawel, Nadine, Nacif, Marcelo, Zavodni, Anna, Jones, Jacquin, Liu, Songtao, Sibley, Christopher T, Bluemke, David A
• Format: Journal Article
• Language: English
• Published: London Elsevier Inc 28.04.2012; BioMed Central; BioMed Central Ltd; Elsevier
• Subjects: Adult; Angiology; Assessments; Binding proteins; Blood; Cardiac patients; Cardiology; Confidence intervals; Contrast agents; Contrast Media; Correlation; Diagnosis; ECV; Extracellular volume fraction; Fibrosis; Fractions; Gadobenate dimeglumine; Gadolinium DTPA; Gadopentetate dimeglumine; Heart diseases; Heart Diseases - diagnosis; Heart Diseases - pathology; Heart muscle; Heart rate; Humans; Image contrast; Image Interpretation, Computer-Assisted; Imaging; Magnetic Resonance Imaging; Male; Maryland; Medicine; Medicine & Public Health; Meglumine - analogs & derivatives; Modified Look-Locker Inversion Recovery; Myocardium; Myocardium - pathology; Observer Variation; Organometallic Compounds; Physiological aspects; Predictive Value of Tests; Radiology; Reference Values; Relaxation time; Reproducibility of Results; Studies; T1 mapping; Time Factors; Volunteers; Young Adult; Maryland; Extracellular volume fraction; ECV; Modified Look-Locker Inversion Recovery; Gadobenate dimeglumine; Gadopentetate dimeglumine; T1 mapping
• ISSN: 1097-6647; 1532-429X; 1532-429X
• DOI: 10.1186/1532-429X-14-26

Myocardial T1 relaxation time (T1 time) and extracellular volume fraction (ECV) are altered in patients with diffuse myocardial fibrosis. The purpose of this study was to perform an intra-individual assessment of normal T1 time and ECV for two different contrast agents. A modified Look-Locker Inversion Recovery (MOLLI) sequence was acquired at 3 T in 24 healthy subjects (8 men; 28 ± 6 years) at mid-ventricular short axis pre-contrast and every 5 min between 5-45 min after injection of a bolus of 0.15 mmol/kg gadopentetate dimeglumine (Gd-DTPA; Magnevist®) (exam 1) and 0.1 mmol/kg gadobenate dimeglumine (Gd-BOPTA; Multihance®) (exam 2) during two separate scanning sessions. T1 times were measured in myocardium and blood on generated T1 maps. ECVs were calculated as ΔR1myocardium/ΔR1blood*1−hematocrit. Mean pre-contrast T1 relaxation times for myocardium and blood were similar for both the first and second CMR exam (p > 0.5). Overall mean post-contrast myocardial T1 time was 15 ± 2 ms (2.5 ± 0.7%) shorter for Gd-DTPA at 0.15 mmol/kg compared to Gd-BOPTA at 0.1 mmol/kg (p < 0.01) while there was no significant difference for T1 time of blood pool (p > 0.05). Between 5 and 45 minutes after contrast injection, mean ECV values increased linearly with time for both contrast agents from 0.27 ± 0.03 to 0.30 ± 0.03 (p < 0.0001). Mean ECV values were slightly higher (by 0.01, p < 0.05) for Gd-DTPA compared to Gd-BOPTA. Inter-individual variation of ECV was higher (CV 8.7% [exam 1, Gd-DTPA] and 9.4% [exam 2, Gd-BOPTA], respectively) compared to variation of pre-contrast myocardial T1 relaxation time (CV 4.5% [exam 1] and 3.0% [exam 2], respectively). ECV with Gd-DTPA was highly correlated to ECV by Gd-BOPTA (r = 0.803; p < 0.0001). In comparison to pre-contrast myocardial T1 relaxation time, variation in ECV values of normal subjects is larger. However, absolute differences in ECV between Gd-DTPA and Gd-BOPTA were small and rank correlation was high. There is a small and linear increase in ECV over time, therefore ideally images should be acquired at the same delay after contrast injection.