ERS3031. High Rate of Identification of Mitral Valve Prolapse on Non-ECG Gated Chest CT
Authors * Denotes Presenting Author
  1. Minji Son *; Bundang Cha Hospital
Primary imaging modality for the diagnosis of mitral valve prolapse (MVP) is echocardiography supplemented by ECG-gated cardiac CT angiography. However, the authors have recently encountered multiple patients with ruptured MVP, initially identified on non-ECG gated chest CT. Notably, there has been no study regarding diagnostic accuracy of MVP on non-ECG gated chest CT. Thus, the purpose of the paper is to evaluate diagnostic accuracy of MVP on non-ECG gated chest CT.

Materials and Methods:
We retrospectively assessed 92 patients who were surgically confirmed MVP and done preoperative non-ECG gated chest CT. The exclusion criteria were poor CT image quality, lacking information about culprit leaflet for MVP on operation record. Finally we assessed 65 patients who were 50 patients with ruptured MVP and 15 patients without ruptured MVP. And as a control, 65 patients, who were without MVP on echo and performed non-gated chest CT within 1months of echo. We analyzed CT findings of “double-line sign” suggesting presence of MVP, and location of culprit leaflet for MVP (A1, 2, 3, P1, 2, 3). A retrospective evaluation was performed by two blind radiologists in a consensus manner for CT findings.

“Double line-sign” to predict ruptured MVP on non-ECG gated chest CT resulted in sensitivity, specificity, negative predictive value, and positive predictive valve of 59%, 99%, 70%, and 97%, respectively. Inter-observer agreement of presence or absence of double line was substantial (kappa value : 0.8). In contrast, only 24.6% (n=16/65) was correctly localized as the culprit lesion on non-ECG gated chest CT.

The high rate of identification of MVP on non-ECG gated chest CT may be explained by the increased mobility of ruptured or redundant leaflet. The result of low diagnostic accuracy for the localization of culprit leaflet for MVP was caused by motion blurring or overlapping between anterior and posterior leaflet. As MVP was frequently seen on non-ECG gated CT, presence of double-line sign should be routinely checked to identify incidental MVP. Familiarity of this CT finding may lead to prompt diagnosis and surgery of ruptured MVP.