A novel alignment procedure to assess calcified coronary plaques in histopathology, post-mortem computed tomography angiography and optical coherence tomography

Evaluating image quality on post-mortem cardiac CT using an anthropomorphic phantom

BACKGROUND

Ischemic heart disease is a major cause of mortality worldwide. Coronary computed tomography angiography (CCTA) has been recognised as a procedure for diagnosing atherosclerotic plaques. One method used to test the diagnostic accuracy of new technical developments on the CT scanner is post-mortem imaging. This study aimed to compare image quality of CCTA on post-mortem hearts scanned inside an anthropomorphic phantom versus scanning directly on the scanner bed, and evaluate which image was most comparable to scanning in-vivo (living patients).

METHODS

Ten post-mortem hearts were scanned using the two methods and ten CCTA in-vivo were included for comparison. Region of interest (ROI) measurements in both the right and left ventricles of the hearts were made and coronary vessel analysis measured plaque burden and composition. To examine the difference between each scanning method, we compared the mean and standard deviation of these measurements. The difference in image quality was also examined visually through images and a dot plot.

RESULTS

A Wilcoxon Signed Rank test showed that ROI measurements from the two methods were significantly different. Mann-Whitney-U tests showed a significant difference between the in-vivo measurements and the two post-mortem scanning methods. Wilcoxon signed-rank tests indicated a significant difference for 4 out of 5 plaque measurements. Visually, a noisier image was seen using the phantom, though it was closer to in-vivo imaging and had a clearer plaque visualisation.

CONCLUSION

A significant difference in image quality between scans taken with the heart directly on the scanner bed compared to inside the phantom, with those inside the phantom being more comparable to in-vivo scans. This highlights the importance of using an appropriate scanning technique when imaging post-mortem organs.

A calcification subtraction method for postmortem coronary computed tomography angiography

Although coronary computed tomography (CT) angiography is a useful tool for evaluating coronary artery lesions both ante- and postmortem, accurate evaluation of the lumen is difficult when highly calcified lesions are present, owing to overestimation of stenosis caused by blooming and partial volume artifacts. In clinical practice, to overcome this diagnostic problem, a subtraction method has been devised to remove calcification by subtracting the precontrast image from the contrast image. In this report, we describe a calcification subtraction method using image analysis software for postmortem coronary CT angiography. This method was devised based on preliminary experimental results showing that the most accurate subtraction was achieved using images reconstructed with a narrower field of view and bone kernel, resulting in higher spatial resolution. This subtraction method allowed evaluation of lumen patency and the degree of stenosis on contrast-enhanced images in a verification using actual specimens where evaluation of the lumen had been difficult because of high calcification. The results were morphologically similar to the macroscopic findings. This method allows more rapid and reliable lesion retrieval and is expected to be useful for postmortem coronary angiography in forensic practice.

Pathobiology of cardiovascular diseases: an update

This article introduces the Second Special Issue of Cardiovascular Pathology (CVP), the official journal of the Society for Cardiovascular Pathology (SCVP). This CVP Special Issue showcases a series of commemorative review articles in celebration of the 25th anniversary of CVP originally published in 2016 and now compiled into a virtual collection with online access for the cardiovascular pathology community. This overview also provides updates on the major categories of cardiovascular diseases from the perspective of cardiovascular pathologists, highlighting publications from CVP, as well as additional important review articles and clinicopathologic references.