סמינר מחלקתי בהנדסה ביו רפואית

יבגני בל
תלמיד המחלקה להנדסה ביו רפואית לתואר שני ירצה בנושא:

Automatic Liver Volume Segmentation and Fibrosis Classification

In this work, we present an automatic method for liver segmentation and fibrosis classification in liver computed-tomography (CT) portal phase scans. The input is a full abdomen CT scan and the output is a liver volume segmentation mask and a fibrosis grade. A multi-stage analysis scheme is applied to each scan, including: volume segmentation, texture features extraction and SVM based classification. Three analysis methods are used: The first approach examines a peripheral band of 11 central slices, since fibrosis is associated with external surface nodularity. A second approach examines the entire liver volume, since large nodules separated by wider scars are irregularly distributed throughout the liver. The features are extracted from every slice and concatenated into a feature vector and subsequently into a feature matrix. The Third approach area of interest is a dilated contour along the segmented liver border, stretching outside and inside the liver area. This approach is targeted to capture contour deformities, as it tends to be lobulated and irregular in fibrosis.
Our data contains portal phase CT examinations from 80 patients, taken with different scanners at Sheba Medical Center. Each examination has a matching Fibroscan grade. The dataset was subdivided into two groups: first group contains healthy cases and mild fibrosis, second group contains moderate fibrosis, severe fibrosis and cirrhosis. Using our automated algorithm, we achieved an average dice index of 0.93±0.05 for segmentation and an average recall of 0.87 for classification. To the best of our knowledge, this is a first end to end automatic framework for liver fibrosis classification; an approach that, once validated, can have potential value in the clinic.

The presented work is joint with Sheba CT Abdomen unit.

העבודה נעשתה בהנחיית פרופ' חיית גרינשפן המחלקה להנדסה ביו-רפואית, אוניברסיטת תל-אביב
ההרצאה תתקיים ביום ראשון 12.11.17, בשעה 14:00
בחדר 315, הבניין הרב תחומי, אוניברסיטת תל אביב