Poster Abstracts: Clinical MRS 312. Determination of Normal Left Atrial and Left Ventricular Diameters by Cardiovascular Magnetic Resonance Imaging Using TrueFISP: Comparison to Two-Dimensional Echocardiograhy

Established normal values are necessary for the identification of pathological cardiac diameters as determined by cardiovascular magnetic resonance (CMR) and important for follow-up studies. We have compared normal diameters for left atrium (LA) and ventricle (LV) between two-dimensional echocardiography (Echo) and CMR using TrueFISP in subjects with no cardiac pathology. Methods: 24 patients (pts) with no cardiac pathology (12 women, 12 men, age 16–77 yr, mean age 51.8 ^ 15.6 yr) were investigated using a CMR imager (Magnetom, Siemens, Erlangen, Germany) and underwent Echo (Hewlett Packer Sonos 2500, Andover, Massachusetts, USA). CMR images were acquired by trueFISP using the horizontal (HLA) and vertical (VLA) long axis plane to measure left atrial (LA) diameters (LAED), left ventricular inferior wall thickness (LVIW), left ventricular enddiastolic (LVEDD) and endsystolic (LVESD) diameters and interventricular septal wall thickness (IVS). LA diameter was also measured in the LV outflow tract view (LVOT). Same diameters were measured by Echo and compared to CMR data. Results: LVEDD was different between men and women in CMR ðp 1⁄4 0:0450Þ: For Echo gender specific differences were present in LVEDD ðp 1⁄4 0:0423Þ; LVESD ðp 1⁄4 0:0298Þ and LVHIT ðp 1⁄4 0:0083Þ: LVEDD was 0.2 cm and LAED 0.8 cm smaller with CMR compared to Echo when measured in LVOT (p $ 0.001). LVEDD was 0.8 cm larger when measured in the VLA by CMR. When LAED was measured in VLA, it was 0.8 cm larger in CMR compared to Echo ðp 1⁄4 0:000Þ: For CMR normal values were determined: LVEDD 3.8–5.6 cm (Mean 4.6 ^ 5 cm, Median 4.5 cm), LVESD 2.0 – 3.3 cm (Mean 2.6 ^ 4 cm, Median 2.6 cm), LVIWT 0.5 – 1.3 cm (Mean 0.9 ^ 0.2 cm, Median 0.9 cm), IWST 0.6–1.3 cm (Mean 1.0 ^ 0.2 cm, Median 0.9 cm), LAED-HLA 3.6-5.7 cm (Mean 4.4 ^ 0.6 cm, Median 4.5 cm), LAED-VLA 3.5 – 5.4 cm (Mean 4.5 ^ 0.5 cm, Median 4.5 cm), LAED-LVOT 2.3 – 3.6 cm (Mean 2.8 ^ 0.4 cm, Median 2.8 cm). Conclusions: There is a good correlation between CMR using TrueFISP and Echo in LA and LV diameters. Diameters measured by CMR as well as by Echo were within the normal ranges, standardized by Echo. We have validated normal ranges of LA and LV diameters for CMR.