Rapid Fire Abstracts
Tomoro Morikawa, MD
Physician
National Cerebral and Cardiovascular Center, Japan
Tomoro Morikawa, MD
Physician
National Cerebral and Cardiovascular Center, Japan
Ohta Yasutoshi, MD, PhD
Head physician
National Cerebral and Cardiovascular Center, Japan
Morita Yoshiaki, MD, PhD
Head Physician
National Cerebral and Cardiovascular Center, Japan
Tatsuya Nishii, MD, PhD
National Cerebral and Cardiovascular Center, Japan
Hiroki Horinouchi, MD, PhD
Physician
National Cerebral and Cardiovascular Center, Japan
Akiyuki Kotoku, MD, PhD
Physician
National Cerebral and Cariovascular Center, Japan
Midori Fukuyama, MD
Physician
National Cerebral and Cardiovascular Center, Japan
Emi Tateishi, MD, PhD
Physician
National Cerebral and Caridovascular Center, Japan
Tetsuya Fukuda, MD, PhD
Director
National Cerebral and Cardiovascular Center, Japan
Extracellular volume fraction (ECV) is used for myocardial property evaluation that is usually assessed at a single time point; however, ECV changes over time in normal myocardium or fibrotic myocardium associated with LGE have not been adequately evaluated. Recently, a method was introduced to predict myocardial contrast medium concentration at any given time point using dynamic T1 mapping and a two-compartment pharmacokinetic model. This method allows for a completely standardized temporal assessment of pathological changes. The purpose of this study was to evaluate the disease characteristics and temporal changes in pharmacokinetic model-derived ECV maps in cardiomyopathy patients.
Methods: This study evaluated 25 cardiomyopathy patients, including 12 with DCM and 13 with HCM, who underwent cardiac magnetic resonance (CMR) examination with dynamic T1 mapping. In addition to routine examinations, including cine and 10-minute late gadolinium enhancement (LGE), native T1 and dynamic T1 maps (2, 5, 9, and 15 min after contrast administration) were obtained using the modified Look-Locker inversion recovery sequence. Pharmacokinetic analysis of myocardial and blood pool gadolinium concentrations was performed using a two-compartment model, and predicted concentration maps (mmol/l) at 7, 10, 15, 20, and 25 minutes after contrast was generated from calculated parameters. ECV values were measured in each myocardial segment based on the 16-segment model at every time point. Based on LGE, segments were classified into LGE-negative remote segments (REMOseg) and LGE-positive segments (LGEseg). For the LGEseg, ROIs were explicitly drawn in hyperenhancement legions on the LGE images. Temporal changes in ECV in REMOseg, LGEseg and ROI and differences in disease were assessed.
Results: 94 REMOseg and 98 LGEseg were identified in DCM, and 116 REMOseg and 92 LGEseg were identified in HCM. ECV(%) values at each time point in REMOseg were 25.8, 26.2, 26.1, 26.2, and 26.3 in DCM, and 24.2, 24.8, 25.0, 25.0, and 25.0 in HCM, with no significant differences (p=0.48). ECV(%) values at each time point in the LGEseg were 34.4, 34.4, 34.4, 35.0, and 35.4 for DCM and 34.9, 35., 36.4, 37.0, and 38.5 for HCM, which were significantly higher for HCM when the temporal factors were considered(p< 0.05). In both DCM and HCM, the LGEseg showed significantly higher values than the REMOseg(p< 0.001). Analysis of all REMOseg over time showed a significant increase in ECV values from 7 min to 10 min, after which a plateau was reached. In contrast, the LGEseg showed a persistent increase from 7 to 25 minutes, indicating a different dynamic pattern than the REMOseg.
Conclusion:
Temporal assessment of ECV from pharmacokinetic modeling shows that ECV does not change significantly after 10 min in non-LGE myocardium, but tends to increase progressively in myocardium presenting with LGE.
