Keywords:
Endocrine disorders, Diagnostic procedure, Computer Applications-General, MR, Cardiac, Metabolic disorders, Tissue characterisation
Authors:
C. Roux1, N. Kachenoura1, P. Kamenicky2, L. Hajji-Besson1, M. J. Graves3, E. Mousseaux4, P. Chanson2, A. Redheuil4; 1Paris/FR, 2Krêmelin-Bicêtre/FR, 3Cambridge/UK, 4Paris Cedex 15/FR
Methods and Materials
This is a longitudinal pilot study performed in an academic center from Sept 2009 to Jan 2013.
Ten consecutive patients with active Cushing’s disease (CD) were included and matched with ten healthy volunteers on age,
sex and heart rate.
Inclusion criteria were: age between 15 and 60 years and Cushing's syndrome of pitutary origin newly diagnosed and untreated.
Patients and volunteers had a cardiac MRI exam shortly after diagnosis and a follow-up exam on average 6 month after cortisol normalization obtained by pituitary adenoma resection.
Imaging protocol included multiplane SSFP cine,
MOLLI T1 mapping sequences before and 15 minutes after contrast injection and late gadolinium enhancement 10 minutes after contrast injection.
Ventricular volumes and mass were measured in MRI before and after treatment from standard cine SSFP in short-axis views.
For T1 mapping,
a mid-ventricular short-axis slice was acquired using a Modified Look-Locker Inversion Recovery (MOLLI)3 sequence during a single breath-hold before contrast and at 15 minutes after a bolus injection (0.2 mmol/kg,
Dotarem,
Guerbet).
The MOLLI sequence was performed using a 3(3)3(3)5 scheme to obtain 11 points on the recovery curve within a single breathhold.
In patients,
myocardial borders were first manually drawn on the original grayscale MOLLI image acquired with the inversion time providing the best contrast between myocardium and LV cavity.
It was then superimposed on the corresponding T1 map and corrected manually to exclude pixels from the LV cavity and epicardial fatty tissues (Figure 1).
Average T1 values for the entire slice were recorded and partition coefficient (λ) was calculated using the previously described formula: Lambda= (nativeR1myo - post-contrast R1myo)/ (native R1LV-Cavity- post-contrast R1LV-cavity); R1 = 1/T1.