Sung Min Ko, Presenter: Nothing to Disclose

Jin-Woo Choi, Abstract Co-Author: Nothing to Disclose

Hweung Kgon Hwang, Abstract Co-Author: Nothing to Disclose

Meong Gun Song, Abstract Co-Author: Nothing to Disclose

To determine the utility of ECG-gated dual-source CT (DSCT) in evaluating planimetered mitral valve area (MVA) and detecting left atrial appendage (LAA) thrombus in patients with atrial fibrillation (AF) and mitral stenosis (MS).

We retrospectively enrolled 112 patients (82 women, 55±10.5 years old) with AF and MS who underwent ECG-gated two-phase DSCT and transthoracic echocardiography (TTE) prior to operation. 76 out of 112 patients underwent cardiac magnetic resonance (CMR). All patients underwent intraoperative transesophageal echocardiography (TEE). MVAs derived with manual planimetry by using cine short-axis DSCT and CMR images obtained through the mitral valve were compared between each other and with grade of MS (mild, moderate, severe) based on TTE assessment. Diagnostic performance of DSCT for the detection of LAA thrombus was determined using intraoperative findings as the reference standard. Image data were independently reviewed by 2 observers blinded to the echocardiographic findings and intraoperative results.

There were 15 patients with mild MS, 57 with moderate MS, and 40 with severe MS by TTE. The interobserver agreement for the planimetered MVA by DSCT was excellent (r=0.91, p< .0001). There was excellent agreement (r= 0.889, p< .001) between DSCT and CMR in measuring MVAs with overestimation (0.13±0.15 cm2) of DSCT. Quantification of the MVA by DSCT (mean, 1.3±0.33 cm2) was well correlated with the severity of MS by TTE (r= 0.65, p< .001). With ROC analysis, discrimination between moderate and severe degrees of MS with DSCT was highly accurate when cutoff MVA (1.15 cm2 in comparison with TTE) was used. With intraoperative results as the reference method, the sensitivity, specificity, and positive and negative predictive values of DSCT for the detection of LAA thrombus were 92.6% (25 of 27 patients), 98.8% (84 of 85 patients), 96.2% (25 of 26 patients), and 97.7% (84 of 86 patients), respectively. Inter-rater agreement was 0.93 between DSCT and intraoperative results, 0.90 between DSCT and TTE, and 0.51 between DSCT and TEE for the detection of LAA thrombus

Two-phase DSCT allows quantitative assessment of MS and excellent diagnostic performance for the detection of LAA thrombus in patients with AF and MS.

Two-phase DSCT provide a useful imaging modality for accurate quantitative assessment of MS by measuring MVA and for the detection of LAA thrombus.

Ko, S, Choi, J, Hwang, H, Song, M, Utility of Dual-Source Computed Tomography for Quantification of Stenotic Mitral Valve Area and Detection of the Left Atrial Appendage Thrombus in Patients with Atrial Fibrillation and Mitral Stenosis.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11015596.html