Amir Davarpanah MD, Presenter: Nothing to Disclose

Cormac Thomas Farrelly MD, Abstract Co-Author: Nothing to Disclose

Saurabh Shah, Abstract Co-Author: Employee, Siemens AG

Sven Zuehlsdorff PhD, Abstract Co-Author: Research grant, Siemens AG

James Christopher Carr MD, Abstract Co-Author: Nothing to Disclose

To compare the multi-echo DFW separation technique (DFW) to standard T1-weighted fat-saturated imaging with shared prepulses (SHARP) for detection of pericardial disease

21 patients with clinical ± echocardiographic suspicion of pericardial disease were evaluated with CMR. SHARP and DFW imaging was carried out on all patients following an intravenous injection of 0.2 mmol/kg of Gadolinium-DTPA. For quantitative analysis, pericardial thickness was measured for both protocols. Results were compared using independent samples t-test. Pericardial thickness of more than 4 mm was considered abnormal. Two readers qualitatively assessed studies for the presence of thickened pericardium using a 4-point scale (1: poor, 2: fair, 3: Good, 4: Excellent). Results were compared based on Intraclass correlation (ICC) and nonparametric test (Wilcoxon).

9 patients were diagnosed with pericardial thickening suggestive of pericarditis (standard; 5.9±1.7mm, Water; 6.4±1.7mm, Fat; 5.7±1.9mm) with no significant difference in measurements between the two protocols (P>0.05). Subjective analysis of pericardial thickening showed significantly higher scores for the DFW protocol (P<0.05; median 3, range 3-4) with excellent inter-reader agreement (α=0.85).

The Multi-echo DFW separation method allows improved identification of pericardial tissue from surrounding fat compared to conventional fat saturated imaging and has the potential to become the CMR technique of choice for assessment of pericardial disease.

Depiction of pericardial disease with Cardiac MR (CMR) is technically challenging, as fat suppression is generally necessary to differentiate parietal pericardium from pericardial fat. Fat suppression techniques including inversion or saturation pre pulses to “null” fat may lead to inhomogeneous fat suppression and increased noise. Fat suppression using basic in and opposed phase imaging is prone to partial-volume effects and may also lead to inconsistent fat suppression. The Dixon fat-water (DFW) separation method has previously been implemented in the liver and heart for improved characterization of liver steatosis and fatty masses, respectively. The DFW method may also be used to improve definition of pericardial tissue by reliably suppressing surrounding fat and has the versatility of being applied as a cine or delayed enhanced imaging technique.

Davarpanah, A, Farrelly, C, Shah, S, Zuehlsdorff, S, Carr, J, Multi-Echo Dixon Fat and Water Separation Method for Diagnosing Pericardial Disease Using Cardiac MRI.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8012542.html