Radwa A. Noureldin MD, MSc, Presenter: Nothing to Disclose

Ronald Ouwerkerk PhD, Abstract Co-Author: Nothing to Disclose

Roderic Ivan Pettigrew MD, PhD, Abstract Co-Author: Nothing to Disclose

Ahmed Medhat Gharib MBChB, Abstract Co-Author: Nothing to Disclose

Obesity has a detrimental effect on cardiac function, we aimed to evaluate relationship between musculoskeletal fat deposition and myocardial function.

Seventy-seven HIPPA-compliant subjects, without history of cardiac disease, were scanned after IRB approval and signing a written informed consent. We used a Siemens Verio 70cm bore 3T-MRI. Short axis (SA) and 4-chamber SSFP cine were obtained for evaluation of global myocardial function; EF, EDV, ESV, SV and LV mass, variables were indexed to BSA. Pericardial fat volume was quantified on SA images at end systole, extended from level of mitral valve to the apex. MRS was performed using PRESS technique, TR/TE = 4000/24ms. PRESS voxel was targeting the vastus lateralis (VL), anterior tibial (AT) and soleus muscles. Musculoskeletal fat fraction (FF) was quantified using Amares/MRUI. IMCL was also calculated. Axial T1 weighted images at L4-L5 level were acquired for abdominal fat measurement.

All subjects were successfully scanned, mean age 51±12 years, 46% were men, and 69% were white, and BMI range 19.4-54.8 and mean value 32±8.7. Mean EF, EDVI, ESVI, SVI and LVMI were 60±12%, 60±15, 23±7, 37±10 and 54±11 respectively. The mean musculoskeletal fat in VL, AT and soleus muscles was 0.06±0.05, 0.05±0.04, and 0.1±0.07 % respectively. In VL muscle; FF inversely correlated with ESVI, EDVI and SVI (r= -0.49, -0.52, 0.43, p<0.001), and was associated with pericardial and abdominal fat volumes (r= 0.3, 0.46, P<0.05), both also correlated with IMCL (0.43, 0.28, p<0.05). In AT muscle; FF inversely correlated with ESVI and EDVI (r= -0.3, -0.3, p<0.05), and was associated with pericardial and abdominal fat volumes (r= 0.35, 0.48, P≤0.01), however, IMCL correlated with pericardial fat volume (0.32, p<0.05). In soleus muscle; FF was associated with pericardial and abdominal fat volumes (r= 0.47, 0.49, P<0.001), IMCL showed same pattern of correlation (r= 0.4, 0.25, P< 0.05).

In population without known cardiac disease, musculoskeletal fat accumulation (lipid fraction) is associated with decreased systolic ejection and diastolic filing (compliance).

Early reduction of cardiac compliance is demonstrated in obesity and correlates with fat accumulation in skeletal muscles.

Noureldin, R, Ouwerkerk, R, Pettigrew, R, Gharib, A, Fat Accumulation in Skeletal Muscle Quantified by MRS: Relationship to Global Myocardial Function.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13025780.html