ACU2E-Net: A novel predict-refine attention network for segmentation of soft-tissue structures in ultrasound images.

Segmentation of anatomical structures in ultrasound images is a challenging task due to existence of artifacts inherit to the modality such as speckle noise, attenuation, shadowing, uneven textures and blurred boundaries. This paper presents a novel attention-based predict-refine network, called ACU2E-Net, for segmentation of soft-tissue structures in ultrasound images. The network consists of two modules: a predict module, which is built upon our newly proposed attentive coordinate convolution; and a novel multi-head residual refinement module, which consists of three parallel residual refinement modules. The attentive coordinate convolution is designed to improve the segmentation accuracy by perceiving the shape and positional information of the target anatomy. The proposed multi-head residual refinement module reduces both segmentation biases and variances by integrating residual refinement and ensemble strategies. Moreover, it avoids multi-pass training and inference commonly seen in ensemble methods. To show the effectiveness of our method, we collect a comprehensive dataset of thyroid ultrasound scans from 12 different imaging centers, and evaluate our proposed network against state-of-the-art segmentation methods. Comparisons against state-of-the-art models demonstrate the competitive performance of our newly designed network on both the transverse and sagittal thyroid images. Ablation studies show that proposed modules improve the segmentation Dice score of the baseline model from 79.62% to 80.97% and 82.92% while reducing the variance from 6.12% to 4.67% and 3.21% in transverse and sagittal views, respectively.

Post liver transplant complications of Budd-Chiari syndrome.

BACKGROUND/PURPOSE: Budd-Chiari syndrome (BCS) is a rare, life-threatening disease characterized by hepatic venous outflow obstruction. Liver transplantation (LT) is widely accepted as an effective therapeutic measure for irreversible liver failure due to BCS. There is debate on differences in the post LT course and complications in patients with BCS as compared to non-Budd-Chiari (NBC) patients. METHOD: In this retrospective study, data on all patients who received a liver transplant for BCS at the Shiraz Organ Transplantation Center between January 1996 and September 2017 were reviewed and compared to data of a control group who had received liver transplants over the same period but due to other causes (NBC). RESULTS: Out of 4225 patients who received liver transplants in the study period, 108 had BCS and an age- and gender-matched control group consisted of 108 NBC cases. The mean ± standard deviation (SD) of model for end-stage liver disease (MELD) scores were 19.1 ± 3 and 20 ± 3 for BCS and NBC groups, respectively (p = 0.33). One-, 3-, 5-, and 10-year survival rates in the BCS group were as follows: 82%, 78%, 76%, and 76% compared with the NBC rates of 83%, 83%, 83%, and 76%, respectively (p = 0.556). There was no difference between the two groups in complication rates after 6 months. In the later period, vascular thrombosis was more common in BCS. CONCLUSIONS: Whole-organ LT from deceased donors in patients with BCS had comparable outcomes with LT due to other causes of end-stage liver disease. In most instances, these patients should receive lifelong anticoagulation.