1 A Novel Approach to Extract Colon Lumen from CT Images for Virtual Colonoscopy 作者 : Dongqing Chen,Zhengrong Liang, Mark R.Wax, Lihong Li 出處 : IEEE,Transaction.

1

A Novel Approach to Extract Colon Lumen from CT Images for Virtual Colonoscopy

作者 :Dongqing Chen ,Zhengrong Liang, Mark R.Wax, Lihong Li

出處 :IEEE ,Transaction on Medical Imaging, Dec. 2000, pp. 1220 - 1226

學生 :林上智指導老師 :張顧耀

2

Outline

IntroductionMethodsResults Conclusion

3

Introduction(1/2)

Colorectal carcinoma is the second leading cause of cancer-related deaths in USA.

Examine the colon require clean colonSegmentation of CT imagesLow-residue diet with ingested contrast sol

utions Enhance materials Remove by computer algorithm

4

Introduction(2/2)

The Method is a multistage approach 1.Image classification (low-level):

A modified self-adaptive on-line vector quantization

technique 2.Extraction (high-level):

A region-growing strategy

5

Outline

IntroductionMethodsResults and DiscussionConclusion

6

Feature Analysis of Image Data

The goal of the low-level processing Classify the body voxel Reduce computing burden

One voxel -> 23dimensional vector ->vector Quantization -> feature vector

Local Volume

(K–L transformation matrix)

7

Feature Analysis of Image Data

2D

old new

8

Vector Quantization

The feature vectors were classified into several classes. Generate class Label voxel to class

9

Vector Quantization

CT Images, there are four classes: 1.Air 2.Soft tissue 3.Muscle 4.Bone or enhanced materials

10

Extraction of the Colon Lumen

The colon lumen consisted of four kinds of labeled voxels: 1.Air 2.Partial volume from air to soft tissue/muscle 3.Enhanced materials 4.Partial volume from enhanced materials to sof

t/muscle

11

Region Growing

12

Region Growing

13

Results

Bowel Preparation Five volunteers

Take a high fluid Low residue diet

Three patients Physical colon cleansing 1000cc of CO2

CT scan Image size:512x512 Slices:300~450

14

Results (1/3)

Total datasets:21 (13 in supine,8 in prone)

15

Results (2/3)

16

Results (3/3)

Segment of colon

17

Conclusion

The electronic colon cleansing technique demonstrated Without the need for pre-procedure physical

bowel cleansing