title: Effect of contrast dose in the quantification of myocardial extra-cellular volume in adenosine stress/rest perfusion cardiac magnetic resonance examinations.
abstract: Background Diffuse myocardial fibrosis can be quantified by calculating extra-cellular volume (ECV) from native and post-contrast T1 values using dedicated single bolus contrast medium injection protocols. Purpose To evaluate differences in T1 maps and myocardial ECV measurements in routine stress/rest perfusion cardiovascular magnetic resonance (CMR) examinations after injection of single and double dose of contrast medium. Material and Methods Thirty-seven consecutive patients (30 men; mean age, 62 ± 13 years) underwent clinically indicated adenosine stress/rest perfusion CMR examination to rule out myocardial ischemia following a conventional split-dose contrast medium injection strategy. Native and post-contrast T1 mapping was performed 15 min after the first (0.1 mmol/kg) and second (0.1 mmol/kg) dose of contrast medium using a breath-held Modified Look-Locker Inversion recovery (MOLLI) sequence. Student's t-test for paired samples, Bland-Altman plots, and concordance-correlation coefficients (CCC) for agreement between T1 and ECV calculations after single and double dose of contrast medium were calculated. Intra- and inter-observer agreement for measurements was also analyzed. Results Myocardial T1 values after single and double dose of contrast medium significantly differed (mean difference of 114.1 ± 19.9 ms, P < 0.01). A single dose of contrast agent provided slightly higher ECV values (mean difference of 2.3 ± 1.1%). CCC for ECV calculations was 0.66. Intra- and inter-observer agreement for all measurements was excellent (CCC ≥ 0.83). Conclusion Quantification of myocardial ECV on conventional stress/rest perfusion CMR examination is feasible. T1 maps obtained 15 min after 0.1 mmol/kg of contrast medium provide slightly higher myocardial T1 measurements and ECV values compared with T1 maps obtained after a total dose of 0.2 mmol/kg.
authors: 1 Cardiothoracic Imaging Division, Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: Meylin
authors: M
authors: Caballeros
authors: 1 Cardiothoracic Imaging Division, Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: Pablo
authors: P
authors: Bartolomé
authors: 2 Siemens Healthcare, Madrid, Spain.
authors: Óscar
authors: Ó
authors: Fernández González
authors: 3 Siemens Healthcare GmbH, Erlangen, Germany.
authors: Andreas
authors: A
authors: Greiser
authors: 1 Cardiothoracic Imaging Division, Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: Loreto
authors: L
authors: García Del Barrio
authors: 1 Cardiothoracic Imaging Division, Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: Jesús
authors: J
authors: Pueyo
authors: 1 Cardiothoracic Imaging Division, Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain.
authors: Gorka
authors: G
authors: Bastarrika
mesh_terms: D000241:Adenosine; D057791:Cardiac Imaging Techniques; D003287:Contrast Media / Q000008:administration & dosage*; D003326:Coronary Circulation; D005080:Exercise Test; D005110:Extracellular Space / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D011446:Prospective Studies; D012146:Rest; D014665:Vasodilator Agents
chemical_list: D003287:Contrast Media; D014665:Vasodilator Agents; D000241:Adenosine
keywords: Heart; adenosine; magnetic resonance imaging (MRI); myocardial ischemia; myocardium