Automatic indicator dilution curve extraction in dynamic-contrast enhanced imaging using spectral clustering

Abstract

Indicator dilution theory provides a framework for the measurement of several cardiovascular parameters. Recently, dynamic imaging and contrast agents have been proposed to apply the method in a minimally invasive way. However, the use of contrast-enhanced sequences requires the definition of regions of interest (ROIs) in the dynamic image series; a time-consuming and operator dependent task, commonly performed manually. In this work, we propose a method for the automatic extraction of indicator dilution curves, exploiting the time domain correlation between pixels belonging to the same region. Individual time intensity curves were projected into a low dimensional subspace using principal component analysis; subsequently, clustering was performed to identify the different ROIs. The method was assessed on clinically available DCE-MRI and DCE-US recordings, comparing the derived IDCs with those obtained manually. The robustness to noise of the proposed approach was shown on simulated data. The tracer kinetic parameters derived on real images were in agreement with those obtained from manual annotation. The presented method is a clinically useful preprocessing step prior to further ROI-based cardiac quantifications.

Reliability, repeatability, and reproducibility of pulmonary transit time assessment by contrast enhanced echocardiography

“…The development of automated algorithms for ROI definition and MTT estimation could enhance clinical feasibility of this novel CEUS tool [ 29 ]. This could create the opportunity to simplify PTT calculation at the bedside.…”

Noninvasive pulmonary transit time: A new parameter for general cardiac performance

“…18 Analysis can be performed on regular contrast echocardiography images. To improve the implementation, calculation of PTT can be fully automated as previously shown by Saporito et al 28 Given the feasibility and accuracy 4 of this measuring technique, CEUS-derived transit times might be a promising, additional parameter of general cardiac function. An additional advantage is that this measurement is less dependent on image quality than other techniques for reflecting overall cardiopulmonary function.…”