Improvement of speckle noise reduction using multi-resolutional coherence measurement in ultrasound image.

Ultrasound (US) images are degraded by speckle noise that reduces the contrast and details of images. But the effective method for speckle noise reduction with keeping edge has been still a challenging point. Coherence measurement has been used to distinguish homogeneous region and coherence regions, e.g. edges, and the edge map obtained from coherence measurement has limitation such as noisy or discontinued edge detection. In this paper, to overcome these problems, the enhanced edge map generation using multi-resolutional coherence measurement is proposed and adaptive wavelet based-speckle noise reduction is performed using the enhanced edge map. The experimental results showed that the enhanced edge map by proposed method contains the robust and linked edge information. Moreover, the results show that the proposed method outperforms the conventional method in preserving edge details.

Improvement in erythropoieis-stimulating agent-induced pure red-cell aplasia by introduction of darbepoetin-α when the anti-erythropoietin antibody titer declines spontaneously.

Anti-erythropoietin antibodies usually cross-react with all kinds of recombinant erythropoietins; therefore, erythropoiesis-stimulating agent (ESA)-induced pure red-cell aplasia (PRCA) is not rescued by different ESAs. Here, we present a case of ESA-induced PRCA in a 36-yr-old woman with chronic kidney disease, whose anemic condition improved following reintroduction of darbepoetin-α. The patient developed progressive, severe anemia after the use of erythropoietin-α. As the anemia did not improve after the administration of either other erythropoietin-α products or erythropoietin-ß, all ESAs were discontinued. Oxymetholone therapy failed to improve the transfusion-dependent anemia and a rechallenge with ESAs continuously failed to obtain a sustained response. However, her anemia improved following reintroduction of darbepoetin-α at 3 yr after the initial diagnosis. Interestingly, anti-erythropoietin antibodies were still detectable, although their concentration was too low for titration. In conclusion, darbepoetin-α can improve ESA-induced PRCA when the anti-erythropoietin antibody titer declines and its neutralizing capacity is lost.