Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Estimation and Tracking of AP-diameter of the Inferior Vena Cava in
  Ultrasound Images Using a Novel Active Circle Algorithm   Medical research suggests that the anterior-posterior (AP)-diameter of the
inferior vena cava (IVC) and its associated temporal variation as imaged by
bedside ultrasound is useful in guiding fluid resuscitation of the
critically-ill patient. Unfortunately, indistinct edges and gaps in vessel
walls are frequently present which impede accurate estimation of the IVC
AP-diameter for both human operators and segmentation algorithms. The majority
of research involving use of the IVC to guide fluid resuscitation involves
manual measurement of the maximum and minimum AP-diameter as it varies over
time. This effort proposes using a time-varying circle fitted inside the
typically ellipsoid IVC as an efficient, consistent and novel approach to
tracking and approximating the AP-diameter even in the context of poor image
quality. In this active-circle algorithm, a novel evolution functional is
proposed and shown to be a useful tool for ultrasound image processing. The
proposed algorithm is compared with an expert manual measurement, and
state-of-the-art relevant algorithms. It is shown that the algorithm
outperforms other techniques and performs very close to manual measurement.

23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio