Johannes Greupner, Presenter: Nothing to Disclose

Elke Zimmermann MD, Abstract Co-Author: Nothing to Disclose

Bernd K. Hamm MD, Abstract Co-Author: Research Consultant, Bayer AG Research Consultant, Toshiba Corporation Stockholder, Siemens AG Stockholder, General Electric Company Research grant, Toshiba Corporation Research grant, Koninklijke Philips Electronics NV Research grant, Siemens AG Research grant, General Electric Company Research grant, Elbit Medical Imaging Ltd Research grant, Bayer AG Research grant, Guerbet AG Research grant, Bracco Group Research grant, B. Braun Melsungen AG Research grant, KRAUTH medical KG Research grant, Boston Scientific Corporation Equipment support, Elbit Medical Imaging Ltd Investigator, Copenhagen Malmo Contrast AB

Marc Dewey MD, Abstract Co-Author: Research grant, General Electric Company Research grant, Bracco Group Research grant, Guerbet SA Research grant, Toshiba Corporation Speakers Bureau, Toshiba Corporation Speakers Bureau, Bayer AG Speakers Bureau, Guerbet SA Consultant, Guerbet SA Author, Springer Science+Business Media Deutschland GmbH Institutional research agreement, Siemens AG Institutional research agreement, Koninklijke Philips Electronics NV Institutional research agreement, Toshiba Corporation

Global left ventricular function is usually represented by values related to the maximal and minimal filling of the left ventricle but offer no information about the underlying hemodynamics. But volume-time curves (VTC) obtained by magnetic resonance imaging (MRI) offer a quantitative assessment of left ventricular hemodynamics. As 64-row computed tomography (64-row CT), despite its lower temporal resolution, can also be used to obtain VTCs, we sought to compare 64-row CT with MRI for static functional parameters as well as VTCs.

A total of 39 patients underwent both MRI and CT with standardized examination protocols. VTCs were generated for CT and MRI. For this we used a bicubic spline model to emulate 20 time points (5% steps) of the cardiac cycle. Furthermore end-diastolic and end-systolic volume (EDV and ESV), ejection fraction (EF) as well as peak filling rate (PFR) and peak ejection rate (PER) were calculated. Data was analyzed using student’s t-test and Bland-Altman plots.

Bland-Altman plots showed no significant systematic errors (p>0.05 for all) for EDV (mean difference -7.2±26.1 ml), ESV (mean difference 0.4±26.1 ml) and EF (mean difference -1.1±7.1%) between MRI and 64-row CT, whereas 64-row CT significantly underestimated the PER (mean difference 36.3±95.7 ml/s, p=0.023) and PFR (mean difference 111.0±98.7 ml/s; p<0.05). Regarding VTC agreement there was a significant overestimation of volume (p<0.05) between the MRI and CT during the early systolic phase (0%-25% of the cardiac cycle) and early diastolic phase (40%-55% of the cardiac cycle).

64-row CT allows reliable assessment of global left ventricular function parameters and VTCs are showing significant agreement with MRI during end-systole and during mid- to end-diastole, but 64-row CT is not suited for assessment of hemodynamic parameters like PER and PFR.

64-row CT is an accurate tool to assess static parameters of left ventricular function, but improvements in temporal resolution are required to accurately reflect left ventricular hemodynamics.

Greupner, J, Zimmermann, E, Hamm, B, Dewey, M, Assessment of Left-Ventricular Volume-Time Curves Using Magnetic Resonance Imaging and 64-Row Computed Tomography.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11014705.html