Correlative Detection of Isolated Single and Multi-Cellular Calcifications in the Internal Elastic Lamina of Human Coronary Artery Samples

Han Wen,Houxun Miao,Catherine P Nguyen,Alejandro Morales Martinez,Thomas C Larsen,Manfred Boehm,Kellan P Moorse,Zu-Xi Yu,Alan T Remaley,Eric E Bennett,Ahmed M Gharib

doi:10.1038/s41598-018-29379-6

Abstract

Histopathology protocols often require sectioning and processing of numerous microscopy slides to survey a sample. Trade-offs between workload and sampling density means that small features can be missed. Aiming to reduce the workload of routine histology protocols and the concern over missed pathology in skipped sections, we developed a prototype x-ray tomographic scanner dedicated to rapid scouting and identification of regions of interest in pathology specimens, thereby allowing targeted histopathology analysis to replace blanket searches. In coronary artery samples of a deceased HIV patient, the scanner, called Tomopath, obtained depth-resolved cross-sectional images at 15 µm resolution in a 15-minute scan, which guided the subsequent histological sectioning and microscopy. When compared to a commercial tabletop micro-CT scanner, the prototype provided several-fold contrast-to-noise ratio in 1/11th the scan time. Correlated tomographic and histological images revealed two types of micro calcifications: scattered loose calcifications typically found in atherosclerotic lesions; isolated focal calcifications in one or several cells in the internal elastic lamina and occasionally in the tunica media, which we speculate were the initiation of medial calcification linked to kidney disease, but rarely detected at this early stage due to their similarity to particle contaminants introduced during histological processing, if not for the evidence from the tomography scan prior to sectioning. Thus, in addition to its utility as a scouting tool, in this study it provided complementary information to histological microscopy. Overall, the prototype scanner represents a step toward a dedicated scouting and complementary imaging tool for routine use in pathology labs.

Highlights

This study of the coronary artery samples of a deceased HIV patient was part of an ongoing clinical study of patients with HIV who develop early coronary artery disease in order to understand the nature of atherosclerosis in this patient population[36]
Correlated findings between the tomographic and histological images confirmed two forms of micro calcification deposits that were present in the coronary artery of the patient
A particular significance of the Tomopath complementary information in this study is that it enabled the detection of isolated and focal micro-calcification in the internal elastic lamina (IEL) which could not be ascertained by histology alone

Summary

Introduction

This study of the coronary artery samples of a deceased HIV patient was part of an ongoing clinical study of patients with HIV who develop early coronary artery disease in order to understand the nature of atherosclerosis in this patient population[36]. Due to a few design optimizations tailored to histopathology samples, Tomopath provided sufficient resolution in paraffin-embedded coronary segments to detect micro calcifications as small as a single cell, and sufficient tissue contrast to show the vessel wall layers in most cases, thereby allowing matching with the subsequent histological images and placement of the micro calcifications in the layered structure of the coronary wall. Correlated findings between the tomographic and histological images confirmed two forms of micro calcification deposits that were present in the coronary artery of the patient

Methods

Results

Conclusion