Author + information
- Michele Emdin,
- Giovanni D. Aquaro,
- Nicola R. Pugliese,
- Annamaria Del Franco,
- Giancarlo Todiere,
- Federico Perfetto,
- Andrea Barison,
- Massimo Lombardi and
- Fondazione Toscana G. Monasterio
Late Gadolinium Enhancement (LGE) technique is currently used for the diagnosis of Cardiac Amyloidosis (CA) by Magnetic Resonance (MRI). However, LGE pattern lacks of sensitivity because it is absent in 30% of patients with CA in previous series.
To test a new method for diagnosis of CA by the evaluation of curves of myocardial signal intensity (SI)/time after gadolinium injection.
Cardiac MRI examination was performed in 60 consecutive patients with previous diagnosis of cardiac AL amyloidosis and 10 healthy control subjects. Protocol included evaluation of morphologic and functional features of CA. Conventional LGE images were also acquired and the presence, extent and pattern of LGE was evaluated. Acquisition of T1-weighted inversion recovery gradient echo horizontal long axis view (inversion time, 250 msec) was repeated every minute after gadolinium injection for 8 minutes. In all the images regions of interest (ROIs) were placed in the following sites: subendocardium, subepicardium, middle layer of interventricular septum, left ventricular cavity and skeletal muscle (the latter considered as reference ROI). A software automatically measured SI for all the ROIs generating a SI/time curve, where time was expressed in heart beat number. For each ROI half time of MRI-signal decay (T1/2) was calculated from the SI/time curves.
The typical LGE pattern for CA was observed in 43/60 patients (72%), while 17 subjects showed morphologic features of CA (indexed left ventricular mass 92.7 ± 34.4 g/m2), but negative LGE. At ROC analysis subendocardial T1/2 allowed to distinguish patients with typical LGE from controls with a sensitivity of 98% and specificity 89% (threshold value >272 beats; area under the curve 0.95). Using the same threshold (>272 beats), an abnormal SI/time curves was detected in 12/17 patients with CA and negative LGE. Then, the analysis of SI/time curve permitted to evidence CA in 92% of patients.
The analysis of SI/time curve after gadolinium injection, which represents a simple way to evaluate gadolinium kinetics in myocardium and blood, may improve the accuracy of MRI-LGE for the diagnosis of CA.
Poster Sessions, Expo North
Saturday, March 09, 2013, 3:45 p.m.-4:30 p.m.
Session Title: What Is Unfolding in Cardiac Amyloidosis Research?
Abstract Category: 23. Pericardial/Myocardial Disease
Presentation Number: 1163-143
- 2013 American College of Cardiology Foundation