Optical Coherence Tomography For Characterization Research Articles

Serial optical coherence tomography for characterization of coronary lithotripsy efficacy: How much is enough?

Serial optical coherence tomography for characterization of coronary lithotripsy efficacy: How much is enough?

Coronary vessel intimal sequence extraction based on prior boundary constraints in optical coherence tomography image

Optical coherence tomography (OCT) is a new technique applied in cardiovascular system. It can detect vessel intimal, small structure of plaque surface and discover small lesions with its high axial resolution and quantification character. Especially with the application of OCT in characterization of coronary atherosclerotic plaque, diagnosis and treatment strategy making, optimizing percutaneous coronary intervention therapy and assessment after stent planting make the OCT become an efficient tool for cardiovascular disease diagnosis and treatment. This paper presents a novel coronary vessel intimal sequence extraction method based on prior boundary constraints in OCT image. On the basis of conventional Chan-Vese model, we modified the evolutionary weight function to control the evolutionary rate of boundary by adding local information of boundary curve. At the same time, we added the gradient energy term and intimal boundary constraint term based on priori boundary condition to further control the evolutionary of boundary curve. At last, coronary vessel intimal is extracted in a sequence way. The comparison with vessel intimal, manual segmented by clinical scientists (golden standard), indicates that our coronary vessel intimal extraction method is robust to intimal boundary blur, distortion, guide wire shadow and plaque disturbs. The results of this study can be applied to clinical aid diagnosis and precise diagnosis and treatment.

Optical coherence tomography for characterization of cardiac allograft vasculopathy in late survivors of pediatric heart transplantation

Optical coherence tomography (OCT) has been shown to reliably detect cardiac allograft vasculopathy (CAV). In recent studies performed in adult heart transplant (HTx) recipients, OCT revealed the presence of vulnerable plaques and complicated coronary artery lesions, thus challenging the current concept that CAV disease is a diffuse concentric and fibrosing vasculopathy. The aim of our study was to characterize CAV by OCT in a young population of HTx recipients. We prospectively enrolled 21 young HTx recipients (mean age 27 years, range 22 to 38 years) to undergo OCT of the left anterior descending coronary artery (LAD) in addition to annual CAV screening by coronary angiography and virtual histology intravascular ultrasound (VH-IVUS). Quantitative OCT analysis was performed at the site of maximal intimal thickness (MIT) for each LAD segment. Patients were 27 years old with a mean time from cardiac transplantation of 14.7 ± 6.8 years. All patients exhibited intimal hyperplasia with an abnormal (>1) intima-to-media ratio. The median (interquartile range) MIT values by OCT were 0.37 (0.22 to 0.54) mm, 0.46 (0.29 to 0.54) mm and 0.34 (0.25 to 0.49) mm in the distal, middle and proximal LAD segments, respectively. Qualitative OCT analysis rarely showed features of vulnerable plaque or complicated lesions. Consistently, at VH-IVUS, the prevalent component at the site of MIT per vessel assessed by OCT was fibrous tissue. Unlike recent evidence in adult HTx recipients, OCT findings of vulnerable plaque and complicated coronary lesions were found to be rare among late survivors of pediatric HTx.

Optical coherence tomography for characterization of cardiac allograft vasculopathy after heart transplantation (OCTCAV study)

Optical coherence tomography (OCT) is a novel intravascular imaging modality with excellent spatial resolution. This study explored the utility of OCT in cardiac transplantation for the detection and characterization of early changes associated with coronary allograft vasculopathy (CAV). Fifteen consecutive patients, 1 to 4 years after transplant with no angiographic evidence of CAV, underwent successful OCT imaging using the Fourier-domain OCT system (C7-XR, St. Jude Medical, St. Paul, MN) in the left anterior descending artery. Analysis included measurements of the lumen, intima, and media layers, and characterization of atherosclerotic plaques. Patients were stratified by intima-to-media (I/M) ratio and classified as normal (≤1) or abnormal (>1). Patients were a mean of 2.8 years after transplant, 58 years old, and 92% were men. OCT imaging revealed 8 of 15 patients had intimal hyperplasia with an I/M ratio >1. Comparing those with I/M ratio of ≤1 and >1, the median (interquartile range) intimal thickness was greater (75 [70-101] vs 206 [97-269]μm, p = 0.03), whereas the media thickness was no different (72 [70-103] vs 94 [73-113]μm, p = 0.53). In addition, 7 of 15 patients had lipid-rich or calcified atherosclerotic plaques. OCT provides high-resolution quantitative imaging of the coronary arteries and its use allows for detailed assessment of the coronary artery wall and early morphologic changes that occur after cardiac transplantation. The clinical predictive value of these OCT-derived measurements remains to be determined.