Matthias Grothoff MD, Presenter: Nothing to Disclose

Lukas H. J. Lehmkuhl MD, Abstract Co-Author: Nothing to Disclose

Janine Hoffmann, Abstract Co-Author: Nothing to Disclose

Christian Luecke, Abstract Co-Author: Nothing to Disclose

Matthias Gutberlet, Abstract Co-Author: Nothing to Disclose

To evaluate the value of different MRI derived parameters to differentiate left ventricular noncompaction of the myocardium (LVNC) in patients with known familial LVNC from other cardiomyopathies.

We examined 11 morphologically affected patients (34.8 years ±18) with known familial LVNC carrying a gene mutation, 11 DCM (32.6 years ±17) and 10 HCM patients compared with 24 healthy volunteers (20.2 years ±6.3) using a 1.5 T scanner and a standard steady state free precession sequence in the 4-chamber view, 2-chamber view and a contiguous set of short axis slices. Total left ventricular muscle mass (MM), the compacted muscle mass (MMcomp), MM-Index=MMI [g/m²], MMnon-comp, percental MMnon-comp, ventricular volumes and function were calculated using the CAAS MRV software (Fig. 1), release 3.3 (Pie Medical Imaging, Maastricht, The Netherlands). Furthermore, inversion recovery gradient echo sequences (IR-GRE) were performed 10-20 min. after the administration of 0.2 mmol/kg body weight Gd-DTPA i.v. (Magnevist, BayerSchering, Berlin, Germany). Additionally, a semi-quantitative segmental analysis according to the 17-segment model of the AHA of the occurrence of increased trabeculations and a ROC-analysis was performed.

The mean EF was significantly reduced (p2/1 in at least one segment demonstrated with a very good sensitivity (100%), but only a poor specificity (27%). None of the LVNC patients demonstrated with intramyocardial late gadolinium enhancement (LGE), but HCM and DCM patients did. Furthermore, increased trabeculations in the basal and septal segments, especially in the segments 4-6, are additional strong indicators for LVNC.

Absolute cMRI quantification of the MMInon-comp with a cut-off of 15 g/m² or the percental MMnon-comp with a cut-off of 25%, together with an absence of LGE and/or increased trabeculations in segments 4-6 allow for a very reliable discrimination of healthy subjects, LVNC and other cardiomyopathies in patients with familial LVNC.

The differentiation between DCM, HCM and LVNC is sometimes difficult. The absolute quantification of muscle mass and the distribution of the trabeculated musculature allow a reliable discrimination.

Grothoff, M, Lehmkuhl, L, Hoffmann, J, Luecke, C, Gutberlet, M, Value of MRI Derived Parameters in the Discrimination of Familial Left Ventricular Noncompaction (LVNC), DCM, and HCM in Comparison to Healthy Volunteers.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11015643.html