ABSTRACT
BACKGROUND: Automatic identification of proper image frames at the end-diastolic (ED) and end-systolic (ES) frames during the review of invasive coronary angiograms (ICA) is important to assess blood flow during a cardiac cycle, reconstruct the 3D arterial anatomy from bi-planar views, and generate the complementary fusion map with myocardial images. The current identification method primarily relies on visual interpretation, making it not only time-consuming but also less reproducible. OBJECITVE: In this paper, we propose a new method to automatically identify angiographic image frames associated with the ED and ES cardiac phases. METHOD: A detection algorithm is first used to detect the key points (i.e. landmarks) of coronary arteries, and then an optical flow method is employed to track the trajectories of the selected key points. The ED and ES frames are identified based on all these trajectories. Our method was tested with 62 ICA videos from two separate medical centers. RESULTS: Comparing consensus interpretations by two human expert readers, excellent agreement was achieved by the proposed algorithm: the agreement rates within a one-frame range were 92.99% and 92.73% for the automatic identification of the ED and ES image frames, respectively. CONCLUSION: The proposed automated method showed great potential for being an integral part of automated ICA image analysis.
Subject(s)
Heart , Image Processing, Computer-Assisted , Algorithms , Coronary Angiography/methods , Coronary Vessels/diagnostic imaging , Diastole , Heart/physiology , Humans , Image Processing, Computer-Assisted/methodsABSTRACT
Tumor-induced osteomalacia (TIO) is typically caused by phosphaturic mesenchymal tumor (PMT) that secretes the phosphaturic hormone, fibroblast growth factor-23 (FGF23), resulting in decreased phosphate reabsorption in kidneys, hypophosphatemia, and finally osteomalacia. Rare cases of malignant tumor manifesting with TIO other than PMT had been reported, although in most of these reports, except one, circulating FGF23 levels were not evaluated and tissue expressing of FGF23 was not confirmed. In this article, we report a case of TIO in a patient with pulmonary small cell carcinoma with liver metastasis. The patient manifested with hypophosphatemia. His circulating level of FGF23 was markedly increased. The expression of FGF23 in tumor cells was confirmed. Furthermore, the regulatory mechanism of FGF23 in this patient was also investigated.