Cardiovascular CT in the diagnosis of pericardial constriction: predictive value of inferior vena cava cross-sectional area.

ABSTRACT

BACKGROUND: The diagnosis of pericardial constriction remains challenging. PURPOSE: We sought to evaluate the predictive value of cardiovascular CT-based measurements of inferior vena cava (IVC) parameters in the diagnosis of pericardial constriction. METHODS: Forty-two consecutive patients referred for assessment of pericardial constriction by 64-slice CT were evaluated. The diagnosis of pericardial constriction was confirmed by clinical history, echocardiography, cardiac catheterization, intraoperative findings, histopathology, or a combination. Diameter and cross-sectional area of the suprahepatic IVC and cross-sectional area of the aorta were measured on a single-axial CT image at the level of the esophageal hiatus. Maximum pericardial thickness was measured. Logistic regression and receiver operating curve analyses were performed. RESULTS: Twenty-two patients had pericardial constriction. Mean age of the 42 patients was 57.1 ± 16.4 years, 57.1% were men. IVC diameter, IVC area, the ratio of IVC to aortic area, and pericardial thickness were all significantly greater in patients with constriction than in patients without (P < .05 for all). IVC-to-aortic area ratio had the highest odds ratio (51; 95% CI, 2.8-922) for the prediction of constriction and remained a significant predictor in multivariable analysis. In nested models, IVC-to-aortic area ratio had incremental value over pericardial thickness for the diagnosis of constriction. IVC-to-aortic area ratio discriminated between patients with and without constriction with an area under the curve of 0.88 on receiver operating curve analysis, with a value ≥ 1.6 having a sensitivity and specificity of 95% and 76%, respectively. Interobserver agreement for IVC-to-aortic area ratio was excellent (intraclass correlation coefficient, 0.98). CONCLUSION: Assessment of IVC-to-aortic area ratio on CT aids with the diagnosis of pericardial constriction and has independent and incremental value over pericardial thickness alone.