COSC 4372编程代写、Python，Java程序代写

日期：2021-10-29 10:41

COSC 4372/6370 Algorithmic Medical Imaging

Assignment 1

Type: N/A

Deadline: See Instructors’ Email

Do this assignment after reviewing the lecture material, then study and comprehend the basic

theory that follows below.

Theory: An imaging scanner has the purpose of generating an image of the structure of an

object. The image generation process of generic scanner may include the following steps

Part 1: Data or Image Collection

 “Cut” the object in small pieces each corresponding to a voxel Vi,j,k

 For each voxel Vi,j,k measure the signal intensity (SI) Si,j,k that originates from material of

the object contained in this voxel

Part 2: Image Reconstruction

 Organize the Si,j,k so they correspond to known relative or absolute positions

Part 3: Image Visualization

 Arrange the Si,j,k in assemblies and visualize them as 1D, 2D or 3D objects ‘objects”, thee

are 1D, 2D or 3D images!

In modern imaging scanner, especially MRI scanners, the user can control (and program)

parameters and specifics in any of these three parts. We focus on the first two parts: how to

collect the data and how to reconstruct them and generate an image. A virtual scanner will be a

piece of code that when executed it generates an image based on:

 The anatomy of the Virtual Object (this is the phantom)

 The properties of the Virtual Object that relate to the particular imaging modality

 How the data are collected and reconstructed (the Scanner Control Code)

The Scanner Control Code is a list of scanner-functions: when each scanner-function is

executed, it performs one of the fundamental tasks needed in the sequence of events to collect

and generate the image. In an actual scanner, scanner functions often control actual hardware:

RF power emitters, cotnrolelrs of magnetic field gradients, ADC parameters etc.

Our first scanner-functions will be

Select_OneVoxel() can select a voxel (i.e. a tiny cube) from inside the object

Acquire_Signal_OnePoint() it acquires the signal from a single point in space

Scanner Control Code A:

Let’s now put together a first version of the Scanner Control Code to acquire a 2D image with

size N1xN2. This image will be generated by collecting the signal from N1xN2 voxels that

belong to the same slice!

/* Algorithm to acquire a slice */

For I = 1 to N1

For j = 1 to N2

Select_OneVoxel()

Acquire_Signal_OnePoint()

Next N2

Next N1

COSC 4372/6370 Algorithmic Medical Imaging

Prof. Nikolaos V Tsekos

Task1

Update the above Scanner Control Code A

(a) What should be the arguments for functions:

Select_OneVoxel() and Acquire_Signal_OnePoint()?

(b) Based on your answer to 1(a), what other pieces of code (well lines …) you should add to

comlwte thae code so that all arguments are known (and passed) to the functions?

Let’s call the updated code as Scanner Control Code B

Task 2

Modify the updated Scanner Control Code B (from Task 1), to scan a 3D using the line-scan.

In case you were not able to perform Task 1, for partial credit you can do the same to the

original Scanner Control Code A

To perform Tasks 3 and 4 refer to text starting below in page 3 of this document

Task 3

Modify Control Code B to collect an YZ slice. Hint: Consider the assignment of indices in the

table in page 3.

For this particular algorithm, how do you determine where is the slice?

Task 4

Assume you want to collect a multislice set that is composed of 3 slices on XY that are parallel

to XY and along axis Z (Figure 3). Re-write algorithm 2 to perform this task

COSC 4372/6370 Algorithmic Medical Imaging

Prof. Nikolaos V Tsekos

Additional Info about Tasks 3 and 4

Axis & index Finding the Axes Using your

Right Hand

Axis 1 or X i First or index finger

Axis 2 Y j Second finger

Axis 3 Z k Thumb