Ching-Li Cheng

Application of scanning electron microscopy and X-ray microanalysis: FE-SEM, ESEM-EDS, and EDS mapping for studying the characteristics of topographical microstructure and elemental mapping of human cardiac calcified deposition

AbstractTo explore the pathogenic mineral formation in a huge cardiolith isolated from the left heart atrium of an 80-year-old male patient, field emission scanning electron microscopy (FE-SEM) was used to analyze the topographic microstructure and perform elemental mapping in a cross-section of the cardiac calcified deposit after dissection. Environmental SEM equipped with an energy dispersive X-ray spectrometer (EDS) was also used to investigate the composition and spatial distribution of elements in the cross-section, and fiberoptic Raman spectroscopy was used to reidentify the chemical composition of designated positions. The results indicated that calcium hydroxyapatite and cholesterol were the main components of the cardiac calculus. The plate-like structures of calcium hydroxyapatite were unevenly spread over the cholesterol of the cardiac calculus. The calcium hydroxyapatite-rich area exhibited higher amounts of C, O, P, and Ca elements as well as trace amounts of N, Na, Mg, and Al, whereas the major concentration of C, minor concentrations of N and O, and trace amounts of P and Ca were observed in the cholesterol-rich area. Hypercholesterolemia associated with calcification of this cardiac calculus was proposed. Both FE-SEM and ESEM energy dispersive X-ray microanalyses were performed directly, for the first time, to provide useful information on the microstructural characteristics and spatial distribution of elements on the surface of human cardiac calculi. FigureThe ESEM micrographs of cholesterol- and calcium hydroxyapatite-rich areas and the corresponding EDS spectra of a cross-sectional cardiac calcified deposit of human

Composition and distribution of elements and ultrastructural topography of a human cardiac calculus.

Trace elements (TEs) may contribute to the formation of calculi or stones or be involved in the aetiopathogenesis of stone diseases. The compositions and spatial distribution of elements from the inner nucleus to outer crust of the cardiac calculus were investigated by energy-dispersive X-ray fluorescence (EDXRF) spectrometer. The surface topograph, distribution map of elements, elemental and chemical compositions were also determined by environmental scanning electron microscope (ESEM)–energy-dispersive X-ray (EDX) analysis. Twenty-five elements were identifiable from 18 positions on the cardiac calculus by EDXRF spectrometer, in which the highest concentrations of toxic TEs (Ni, Pt, Hg, Sn, Pb, W, Au, Al, Si) and higher levels of essential TEs (Ca, Sr, Cr, P) were detected. A moderate positive Pearson’s correlation between TEs concentrations of Mg, Ca or P and location differences from centre to periphery in the cardiac calculus was observed. A positive correlation was also found for Ca/Zn and Ca/Cu, indicating the gradual increase of calcium concentration from inner nucleus to outer crust of cardiac calculus. The drop-like nodules/crystals on the surface of petrous part of cardiac calculus were observed from ESEM analysis. ESEM–EDX analysis determined the calculus to be predominantly composed of calcium hydroxyapatite and cholesterol, as indicated by the petrous surface and drop-like nodules/crystals, respectively. This composition was confirmed using a portable Raman analyser. The spatial distribution analysis indicated a gradual increase in Mg, P and Ca concentrations from the inner nucleus to the outer crust of the cardiac calculus. The major chemical compositions of calcium hydroxyapatite and cholesterol were detected on this cardiac calculus.

Spectral and morphological classification of different chronic and acute Taiwanese gallstones via FTIR, SEM and ESEM-EDX microanalyses

BACKGROUND Gallstone disease is one of the leading upper gastrointestinal surgical problems in different countries. AIMS To analyze the chronic gallstones and acute gallbladder sludge retrieved from 36 Taiwanese patients. METHODS FTIR microspectroscopy was used to classify the types of gallstones, and an ESEM-EDX microanalysis was first applied to determine the microstructural features and elemental compositions of the various gallstones. Bacteria presented on the surface of gallstones were also detected by SEM. RESULTS Four types of gallstones were obtained from these 36 Taiwanese patients: calcium bilirubinate (CaBR) stones (30.6%), cholesterol stones (19.4%), mixed stones including 6 subtypes (47.2%), and acute gallbladder sludge (2.8%) made of CaBR and protein/insoluble biomaterials. Bacteria imprints and bacterial discharges or bacterial biofilms were also found on the surface of gallstones and acute sludge under a SEM observation. ESEM-EDX results revealed that calcium was found to be the main constituent of all of the types of stones except cholesterol stones, and aluminum was also presented in most of the stones and sludge samples. Chloride was only detected in the acute gallbladder sludge. CONCLUSION FTIR spectra, morphological features, and elemental compositions of the acute gallbladder sludge were different from those of the chronic gallstones.

Ex vivo assessment of valve thickness/calcification of patients with calcific aortic stenosis in relation to in vivo clinical outcomes

Calcific aortic stenosis (AS) plays a critical role in the risk of cardiovascular disease. This preliminary study examined the relationship between the ex vivo valve thickness/calcification and in vivo clinical outcomes of Chinese patients with calcific AS. Six Chinese patients (3 patients with tricuspid aortic valves (TAV)) and 3 patients with. bicuspid aortic valves (BAV) with calcific AS undergoing heart valve replacement were initially chosen for this study. In vivo medical imaging of these calcific AS patients was evaluated using computed tomography and echocardiography. The ex vivo measurements including the actual thickness, calcified area and components of the calcified aortic values excised were performed by a digimatic caliper, X-ray equipment with a cellSens imaging analysis and portable Raman spectroscopy, respectively. Six patients were diagnosed with symptomatic moderate-to-severe AS. The thickness of noncoronary (N) leaflet in the excised TAV was significantly thicker than left-coronary (L) leaflet (p < 0.01), and right-coronary (R) leaflet was also thicker than L (p < 0.05), but no significant difference occurred between N and R (p > 0.05). The extent of calcification in the excised TAV was a statistically significant difference between N and L (p < 0.01) and between R and L (p < 0.01), respectively. However, there was no significant difference between R and L in both thickness and calcification for the excised BAV (p > 0.05). The patients No. 1-3 were found to be TAV with partial commissural fusion. The patient No. 4 was classified as a type 1 NL-BAV morphotype, but both patients 5 and 6 were found to be true BAV (type 0 lateral-BAV). Each calcified valve leaflet was composed of apatites, proteins (collagen and proteoglycan), and a small amount of β-carotene and cholesterol after Raman spectral determination. The calcified nodules of each valve leaflet were predominately identified to be calcium hydroxyapatite and type-B carbonate apatite. However, octacalcium phosphate was also detected in the protein-rich part of calcified valve leaflets. A positive correlation was observed between thickness and calcification for both excised TAV and BAV after ex vivo examinations. Moreover, a negative relationship was obtained among in vivo AVA index, ex vivo thickness and ex vivo calcification for these calcific AS patients.

Echocardiographic manifestations and chemical composition of stenotic bicuspid aortic valves

AbstractBicuspid aortic valve (BAV) is an inherited form of heart disease with only two aortic valve leaflets via a disorder of cardiac valvulogenesis. We investigated the in vivo echocardiographic features of cardiac morphology in patients with BAV and the ex vivo compositional components of all the excised BAV leaflets isolated from BAV patients. Three BAV patients were randomly selected. All patients underwent 2D transthoracic echocardiography (TTE) with a Doppler ultrasound tool. The compositional components of each respective BAV leaflet for all the excised BAVs were determined by a portable fiber-optic Raman spectroscopy. Preoperative TTE revealed the thickened and calcified BAV leaflets, and stenotic aortic flow for all BAV patients. These BAV patients exhibited severe aortic stenosis (AS) by the lower values of aortic valve area (AVA) index. One patient showed a more significant left ventricle hypertrophy, whereas two patients exhibited a significant aortic regurgitation (AR). In addition, three different Raman spectral patterns were summed up from 121 randomized Raman determinations for all the excised BAV leaflets. The main calcified deposition in each BAV leaflet was formed by large amounts of calcium hydroxyapatite and type-B carbonate apatite (Raman bands at 960 and 1070 cm−1). The calcified BAV leaflets were composed of different compositional components such as calcium hydroxyapatite, type-B carbonate apatite, lipids, proteins, cholesterol and β-carotene. The rare NL subtype of type 1 BAV morphotype was found in one patient, but two patients had the purely BAV morphotype with two equal-sized leaflets.

New morphological classification of congenital quadricuspid aortic valve and its histopathologic features

We report a 52-year-old male patient who had a quadricuspid aortic valve (QAV) associated with aortic regurgitation (AR) and left ventricular hypertrophy (LVH). A new accessory cusp (ACC) with maximum thickness than other cusps was located between right coronary cusp (RCC) and left coronary cusp (LCC). The histopathological features revealed markedly thickened and distorted cusp architecture with fibrosis and/or myxomatous degeneration in both non-coronary cusp (NCC) and ACC. Two equal sizes for larger cusps (RCC and NCC) and two equal sizes for smaller cusps (LCC and ACC) were obtained. This QAV belonged to type C QAV of Hurwitzs classification, but also suggested as a modified type III of Jagannaths classification or a new type V of Nakamuras classification by locating ACC between RCC and LCC.

Cost-utility analysis of direct VAD versus double bridges to heart transplantation in patients with refractory heart failure

This study compared the cost‐utility of direct ventricular assist device (VAD) vs double bridges, extracorporeal membrane oxygenation (ECMO) before VAD, to heart transplantation in patients with refractory heart failure.

Dual-Energy Computed Tomography Gemstone Spectral Imaging: A Novel Technique to Determine Human Cardiac Calculus Composition.

Objective Understanding the chemical composition of any calculus in different human organs is essential for choosing the best treatment strategy for patients. The purpose of this study was to assess the capability of determining the chemical composition of a human cardiac calculus using gemstone spectral imaging (GSI) mode on a single-source dual-energy computed tomography (DECT) in vitro. Methods The cardiac calculus was directly scanned on the Discovery CT750 HD FREEdom Edition using GSI mode, in vitro. A portable fiber-optic Raman spectroscopy was also applied to verify the quantitative accuracy of the DECT measurements. Results The results of spectral DECT measurements indicate that effective Z values in 3 designated positions located in this calculus were 15.02 to 15.47, which are close to values of 15.74 to 15.86, corresponding to the effective Z values of calcium apatite and hydroxyapatite. The Raman spectral data were also reflected by the predominant Raman peak at 960 cm−1 for hydroxyapatite and the minor peak at 875 cm−1 for calcium apatite. Conclusions A potential single-source DECT with GSI mode was first used to examine the morphological characteristics and chemical compositions of a giant human cardiac calculus, in vitro. The CT results were consistent with the Raman spectral data, suggesting that spectral CT imaging techniques could be accurately used to diagnose and characterize the compositional materials in the cardiac calculus.