MEDICAL IMAGING

ByAnuja Kulkarni1000722132

LIST OF ACRONYMS CAT - Computed Axial Tomography CT - Computed Tomography DICOM - Digital Imaging and Communications in Medicine EEG - Electroencephalography EKG - Electrocardiography fMRI- Functional Magnetic Resonance Imaging JFIF- JPEG File Interchange Format JPEG- Joint Photographic Experts Group JPIP- JPEG 2000 Interactive Protocol MEG - Magnetoencephalography MRI - Magnetic Resonance Imaging NMR- Nuclear Magnetic Resonance PNG- Portable Network Graphics RF- Radio Frequency SSIM- Structural Similarity

INTRODUCTION Medical imaging as the name suggests is the

technique and process used to create images of parts and functions of human body for clinical purposes.

It is a medical procedure seeking to reveal, diagnose or examine disease. [1]

There are two types of medical imaging, they are- Invisible light medical imaging- radiology /clinical

imaging

Visible light medical imaging- involves digital video or still pictures that can be seen without special equipment.

IMAGING TECHNOLOGIES Radiology: [2]Two forms of radiographic images are in use in medical imaging; projection radiography and fluoroscopy.

Figure 1: Digital Radiography

MAGNETIC RESONANCE IMAGING AND FIDUCIARY MARKERS A magnetic resonance imaging instrument, uses powerful

magnets to polarise and excite hydrogen nuclei in water molecules in human tissue, producing a detectable signal which is spatially encoded, resulting in images of the body. [3]

Fiduciary MarkersFiduciary markers are used in a wide range of medical imaging applications. Images of the same subject produced with two different imaging systems may be correlated by placing a fiduciary marker in the area imaged by both systems. [4]

Figure 3: Fiducial Marker Example

Figure 2: fMRI scan

PHOTO-ACOUSTIC IMAGING AND TOMOGRAPHY Photo acoustic imaging is a recently developed hybrid

biomedical imaging modality based on the photo acoustic effect. [5]

Tomography is the method of imaging a single plane, or slice, of an object resulting in a tomogram. [5]

Figure 4: Computed tomography of brain

CREATION OF THREE-DIMENSIONAL IMAGES

Recently, techniques have been developed to enable CT, MRI and ultrasound scanning software to produce 3D images for the physician. [6]

To produce 3D images, many scans are made, then combined by computers to produce a 3D model, which can then be manipulated by the physician.

Other proposed or developed techniques include: Diffuse optical tomography Elastography Electrical impedance tomography Optoacoustic imaging Ophthalmology

COMPRESSION OF MEDICAL IMAGES JPEG 2000 is the state-of-the-art image

compression DICOM standard for storage and transmission of medical images. [7]

Figure 5: Comparison of JPEG2000 with JPEG [8]

COMPRESSION OF MEDICAL IMAGES

JPIP (JPEG 2000 Interactive Protocol) is a compression streamlining protocol that works with JPEG 2000 to produce an image using the least bandwidth required. [9]

JPIP has the capacity to download only the requested part of a picture, saving bandwidth, computer processing on both ends, and time. [10]

BLOCK DIAGRAM OF JPEG 2000 [11]

Figure 6: Block diagram of JPEG Encoder/decoder [11]

NON-DIAGNOSTIC IMAGING (NEUROIMAGING) Neuroimaging has also been used in experimental

circumstances to allow people to control outside devices, acting as a brain computer interface. [12]

Neuroimaging falls into two broad categories:• Structural imaging• Functional imaging which is used to diagnose

metabolic diseases and lesions on a finer scale (such as Alzheimer's disease)

Figure 7: 3D MRI section of the head [13]

PROPOSED WORK This project introduces the concept of medical imaging and

divulges into its technologies like MRI, tomography, ultrasound etc. It will also compare the compression techniques of medical imaging i.e. JPEG2000 and JPIP on the basis of their bit rates, SSIM index [14], and complexity.

This project proposes to demonstrate creation of 3D images of CT/MRI scan from a normal 2D image. It also shows some circumstances of neuroimaging i.e non-diagnostic medical imaging as in Figure 6.

REFERENCES1. http://en.wikipedia.org/wiki/Medical_imaging2. L.F.Squire and R.A.Novelline Squire's fundamentals of radiology (5th

ed.). Harvard University Press. ISBN 0-674-83339-2  1997; http://en.wikipedia.org/wiki/Image:FMRI.jpg

3. M. Xu and L.H. Wang ; "Photoacoustic imaging in biomedicine". Review of Scientific Instruments 77 (4): 041101. doi:10.1063/1.2195024; 2006

4.  G.T.Herman, “Fundamentals of computerized tomography: Image reconstruction from projection” , 2nd edition, Springer, 2009

5. S.Richard., and C. Cobbold, Foundations of Biomedical Ultrasound, Oxford University press pp. 422–423. 978-0-19-516831-0

6. A. Yamani; A novel pulse-echo technique for medical three dimensional imaging; IEEE trans med imaging; Volume 16 Issue 6 Pages 938-942; Dec 1997

7. A.Khademi and S.Krishnan ; Comparison of JPEG 2000 and other lossless compression schemes; Paper in Engineering in medicine and biology society (IEEE EMBS);2005

REFERENCES8.http://en.wikipedia.org/wiki/

File:JPEG_JFIF_and_2000_Comparison.png(Figure 5)9. eeweb.poly.edu/~yao/EE3414/JPEG.pdf (figure 6)10.http://en.wikipedia.org/wiki/

File:JPEG_JFIF_and_2000_Comparison.png (Figure 6)11. Microsoft and NASA Bring Mars Down to Earth Through the

WorldWide Telescope (07.12.10) - NASA12. A.G.Filler, “The history, development, and impact of computed

imaging in neurological diagnosis and neurosurgery: CT, MRI, DTI: Nature Proceeding DOI: 10.1038/npre.2009.3267.5.Neurosurgical Focus (in press); 2009

13. http://en.wikipedia.org/wiki/Neuroimaging (Figure7)/ Picture reference: sbharris on wikipedia

14. http://en.wikipedia.org/wiki/Structural_similarity