Commentary

Semi-quantitative assessment of tricuspid regurgitation on contrast-enhanced multidetector CT

La enfermedad valvular cardíaca es un problema clínico que se ha estudiado con técnicas de imagen clásicas como la ecocardiografía o la RM. El avance tecnológico de la TC permite obtener imágenes estáticas y dinámicas con las que hacer un análisis morfológico y, en muchas ocasiones, funcional. A pesar que actualmente está solo indicada en los pacientes en los que la ecocardiografía o la RM no son concluyentes o están contraindicadas, la TC multidetector permite diagnosticar la estenosis o insuficiencia por planimetría, valorar y cuantificar el calcio valvular, y mostrar las repercusiones funcionales en el resto de estructuras cardíacas. Teniendo en cuenta que la TC multidetector es una técnica cada día más utilizada para el diagnóstico de la enfermedad isquémica, creemos interesante que el radiólogo conozca la potencialidad que esta técnica tiene en el estudio de la afección valvular.

Heart valve disease is a clinical problem that has been studied with classical imaging techniques like echocardiography and MRI. Technological advances in CT make it possible to obtain static and dynamic images that enable not only a morphological but also a functional analysis in many cases. Although it is currently indicated only in patients with inconclusive findings at echocardiography and MRI or those in whom these techniques are contraindicated, multidetector CT makes it possible to diagnose stenosis or regurgitation through planimetry, to evaluate and quantify valvular calcium, and to show the functional repercussions of these phenomena on the rest of the structures of the heart. Given that multidetector CT is being increasingly used in the diagnosis of ischemic heart disease, we think it is interesting for radiologists to know its potential for the study of valvular disease.

To retrospectively determine the value of a volumetric ventricle analysis for the assessment of right ventricular dysfunction in patients with suspected pulmonary embolism (PE) by using image data from non-electrocardiographically (ECG)-gated multidetector computed tomography angiography (CTA).

Hypothesizing that the presence of PE and the embolus location correlated with right ventricular dysfunction, we retrospectively analyzed 100 non–ECG-gated pulmonary CTA datasets of patients with central, peripheral, and without PE. Right ventricle/left ventricle (RV/LV) diameter ratio measured in transverse sections (RV/LV_trans), four-chamber view (RV/LV_4ch), and RV/LV volume ratio (RV/LV_vol) were assessed on CT images. The results were correlated with the embolus location, the 30-day mortality rate, and the necessity of intensive care treatment.

All CT parameters showed statistically significant differences between all patients groups depended on embolus location. The receiver operating characteristic analysis RV/LV_vol showed the strongest discriminatory power to differ between patients with central and without PE and between patients with central and peripheral PE (central PE vs. no PE: RV/LV_vol = 0.932, RV/LV_trans = 0.880, and RV/LV_4ch = 0.811, central PE vs. peripheral PE: RV/LV_vol = 0.950, RV/LV_trans = 0.849, and RV/LV_4ch = 0.881), indicating a correlation with embolus location predisposing for RVD. For the identification of high-risk patients with PE all three CT parameters showed statistically significant values (P < .0001), whereas in the receiver operating characteristic analysis, RV/LV_vol had the strongest discriminatory power (RV/LV_vol = 0.819, RV/LV_trans = 0.799, and RV/LV_4ch = 0.758).

Ventricle volumetry of non–ECG-gated CTA allows the assessment of right ventricular dysfunction in patients with acute PE. Compared to unidimensional measurements, a volumetric analysis seems to be slightly superior to identify high-risk patients with adverse clinical outcome. However, the method is more time consuming and requires dedicated software tools compared to unidimensional parameters, which is disadvantageous in an emergency setting.