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Browse Prior Art Database

Digital Method for Simulation of Lung Nodules

IP.com Disclosure Number: IPCOM000120568D
Original Publication Date: 1991-May-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 3 page(s) / 100K

Publishing Venue

IBM

Related People

Inaoka, N: AUTHOR [+2]

Abstract

Disclosed is a system for simulating lung nodules (lung tumor shadows) using digital image processing technologies. The density profile for nodule generation is defined as a half-cycle of a sine curve or a SINC (sin(x)/x) function starting from the nodule's two-dimensional center of gravity. The operator determines the shape, the contrast, and its orientation in space by manipulation. In addition to plain nodules, the system can simulate two roentgenological characteristics related to lung nodules. One is a cavity in the tumor, and the other is "a silhouette sign", a sign of pathological changes in the foreground or background of the nodule.

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Digital Method for Simulation of Lung Nodules

      Disclosed is a system for simulating lung nodules (lung
tumor shadows) using digital image processing technologies. The
density profile for nodule generation is defined as a half-cycle of a
sine curve or a SINC (sin(x)/x) function starting from the nodule's
two-dimensional center of gravity.  The operator determines the
shape, the contrast, and its orientation in space by manipulation. In
addition to plain nodules, the system can simulate two
roentgenological characteristics related to lung nodules. One is a
cavity in the tumor, and the other is "a silhouette sign", a sign of
pathological changes in the foreground or background of the nodule.

      The processes of nodule generation are shown in Fig. 1.
Initially, the operator decides the orientation and uses a digitizer
to draw a closed curve to represent the shape of the nodule in the
digital X-ray image on a display. Otherwise, the operator can specify
a circular shape, its position, and its size on a millimeter scale.

      Next, the operator determines the density profile of the nodule
as either a sine curve or a SINC function, and inputs a value for the
contrast between the two-dimensional center of gravity and the
boundary of drawing nodule. This value is determined by using either
the ratio or difference. Immediately, the system calculates the
density slopes from the center of gravity to each boundary point in
proportion to the two-dimensional distance. This means that the
center of gravity has the highest density, the edge points have the
lowest densities, identical to those of their backgrounds, and the
degree of decrease depends on the half-cycle of the selected function
(Fig. 2). Until this phase, no generated nodules appear in the X-ray
image...