Abstract
Purpose
We studied enhanced method to view the vessels in the brain using Magnetic Resonance Angiography (MRA). Noticing that Maximum Intensity Projection (MIP) image is often used to evaluate the arteries of the neck and brain, we propose a new method for view brain vessels to stereo image in 3D space with more superior and more correct compared with conventional method.
Materials and Methods
We use 3T Siemens Tim Trio MRI scanner with 4 channel head coil and get a 3D MRA brain data by fixing volunteers head and radiating Phase Contrast pulse sequence. MRA brain data is 3D rotated according to the view angle of each eyes. Optimal view angle (projection angle) is determined by the distance between eye and center of the data. Newly acquired MRA data are projected along with the projection line and display only the highest values. Each left and right view MIP image is integrated through anaglyph imaging method and optimal stereoscopic MIP image is acquired.
Results
Result image shows that proposed method let enable to view MIP image at any direction of MRA data that is impossible to the conventional method. Moreover, considering disparity and distance from viewer to center of MRA data at spherical coordinates, we can get more realistic stereo image. In conclusion, we can get optimal stereoscopic images according to the position that viewers want to see and distance between viewer and MRA data.
Conclusion
Proposed method overcome problems of conventional method that shows only specific projected image (z-axis projection) and give optimal depth information by converting mono MIP image to stereoscopic image considering viewers position. And can display any view of MRA data at spherical coordinates. If the optimization algorithm and parallel processing is applied, it may give useful medical information for diagnosis and treatment planning in real-time.
References
1. Jackowski C, Aghayev E, Sonnenschein M, Dirnhofer R, Thali MJ. Maximum intensity projection of cranial computed tomography data for dental identification. International Journal of Legal Medicine. 2006. 120:165–167.
2. Fishman EK, Ney DR, Heath DG, Corl FM, Horton KM, Johnson PT. Volume rendering versus maximum intensity projection in CT angiography: what works best, when, and why. Radiographics. 2006. 26:905–922.
3. Lee J, Chung TS, Lee KY, Suh SH. Comparison of non-invasive imaging studies in the evaluation of carotid artery stenosis and occlusion: CT angiography, time-of-flight MR angiography and contrast-enhanced MR angiography. J Korean Soc Magn Reson Med. 2011. 15:234–241.
4. Kim SM, Lee DH, Choi JW, Choi BS, In HS. Diagnosis of vertebral artery ostial stenosis on contrast-enhanced MR angiography: usefulness of a thin-slab MIP technique. J Korean Soc Magn Reson Med. 2011. 15:77–81.
5. Lee CM, Ryu CW, Kim KW. Assessment of carotid geometry by using the contrast-enhanced MR angiography. J Korean Soc Magn Reson Med. 2010. 14:47–55.
6. Tsuchiya K, Katase S, Yoshino A, Hachiya J, Yodo K. Preliminary evaluation of volume-rendered three-dimensional display of time-of-flight MR angiography in the diagnosis of intracranial aneurysms. Neuroradiology. 2001. 43:633–636.
7. Shapiro LB, Tien RD, Golding SJ, Tötterman SM. Preliminary results of a modified surface rendering technique in the display of magnetic resonance angiography images. Magn Reson Imaging. 1994. 12:461–468.
8. Iriberri JD, Vázquez PP. Depth-enhanced maximum intensity projection. IEEE/EG International Symposium on Volume Graphics. 2010. 93–100.
9. Guttman MA, McVeigh ER. Techniques for Fast Stereoscopic MRI. Magn Reson Med. 2001. 46:317–323.
10. Ianir AI, Leonid PY. New methods to produce high quality color anaglyphs for 3-D Visualization. ICIAR. 2004. 2:273–280.
11. Gatesy SM, Shubin NH, Jenkins FA. Anaglyph stereo imaging of dinosaur track morphology and microtopography. Paleontologia Electronica. 2005. 8:10–22.
12. Smith JR, Connell SD, Swift JA. Stereoscopic display of atomic force microscope images using anaglyph techniques. J Microsc. 1999. 196:347–351.
13. Ahn CB, Kim CY, Park HJ, Oh SJ. f-MRI with three-dimensional visual stimulation. J Korean Soc Magn Reson Med. 2005. 9:24–29.