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3D MRI Brain Anatomy
3D MRI Brain Anatomy Mohamed 23,568 Views • 2 years ago

I call this technique deep rendering. I basically stacked graphical cross-sections (in this case, MRI rendering data), using proper increments and clip through them with the camera. This way I am able to explore all internal components in full 3D real-time.

I actually was able to figure out how to colorize different organs to help distinguish them apart from each other but couldn't get the shader to render real-time in Maya.

Credit: MRI scans courtesy of University of Washington Digital Anatomist Program

From axons to tracts
From axons to tracts Mohamed 21,054 Views • 2 years ago

The complex circuitry interconnecting different areas in the brain, known collectively as white matter, is composed of millions of axons organized into fascicles and bundles. Upon macroscopic examination of sections of the brain, it is difficult to discern the orientation of the fibers. The same is true for conventional imaging modalities. However, recent advancements in magnetic resonance imaging (MRI) make such task possible in a live subject. By sensitizing an otherwise typical MRI sequence to the diffusion of water molecules it is possible to measure their diffusion coefficient in a given direction1. Normally, the axonal membrane and myelin sheaths pose barriers to the movement of water molecules and, thus, they diffuse preferentially along the axon2. Therefore, the direction of white matter bundles can be elucidated by determining the principal diffusivity of water. The three-dimensional representation of the diffusion coefficient can be given by a tensor and its mathematical decomposition provides the direction of the tracts3; this MRI technique is known as diffusion tensor imaging (DTI). By connecting the information acquired with DTI, three-dimensional depictions of white matter fascicles are obtained4. The virtual dissection of white matter bundles is rapidly becoming a valuable tool in clinical research.

Our journey begins with a transverse section of tightly packed axons as seen through light microscopy. Although represented as a two-dimensional "slice", we see that these axons in fact resemble tubes. A simulation of water molecules diffusing randomly inside the axons demonstrates how the membranes and myelin hinder their movement across them and shows the preferred diffusion direction --along the axons. The tracts depicted through DTI slowly blend in and we ride along with them. As we zoom out even more, we realize that it is a portion of the corpus callosum connecting the two sides of the brain we were traveling on and the great difference in relative scale of the individual axons becomes evident. The surface of the brain is then shown, as well as the rest of the white matter bundles--a big, apparently chaotic tangle of wires. Finally, the skin covers the brain.

With the exception of the simulated water molecules, all the data presented in the animation is obtained through microscopy and MRI. Computer algorithms for the extraction of the cerebral structures and a custom-built graphics engine make our journey through the brain's anatomy possible in a living person.

Micrograph courtesy of Dr. Christian Beaulieu, University of Alberta.
Music by Mario Mattioli.

References:
1. Stejskal, E.O., et al., J. Chem. Phys., 1965. 42:
2. Beaulieu, C., NMR Biomed., 2002. 15:435-55.
3. Basser, P.J., et al., J. Magn. Reson. B, 1994. 103:247-54.
4. Mori, S., et al., NMR Biomed., 2002. 15:468-80.

The ABC's of Adult CPR Part 2
The ABC's of Adult CPR Part 2 Mohamed 20,100 Views • 2 years ago

The ABC's of Adult CPR

Subcutaneous Pattern Suture
Subcutaneous Pattern Suture M_Nabil 13,805 Views • 2 years ago

Subcutaneous Pattern Suture

Deep Tie
Deep Tie M_Nabil 14,273 Views • 2 years ago

Deep Tie

Instrumental Tie
Instrumental Tie M_Nabil 9,495 Views • 2 years ago

Instrumental Tie

Use of Skin Stapler Remover
Use of Skin Stapler Remover M_Nabil 15,881 Views • 2 years ago

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Lateral internal sphincterotomy
Lateral internal sphincterotomy Mohamed 42,387 Views • 2 years ago

Lateral internal sphincterotomy

Interscalene Block
Interscalene Block M_Nabil 9,824 Views • 2 years ago

Interscalene Block

Off-Pump CABG in Dextrocardia
Off-Pump CABG in Dextrocardia DrHouse 10,579 Views • 2 years ago

Off-Pump CABG in Dextrocardia; A New Challenge for a New Era

Laparoscopic Sleeve Gastrectomy Operation
Laparoscopic Sleeve Gastrectomy Operation Mohamed 10,259 Views • 2 years ago

Laparoscopic Sleeve Gastrectomy Operation

Cholecystectomy & Retroperitoneal Tumor Removal
Cholecystectomy & Retroperitoneal Tumor Removal Mohamed 17,700 Views • 2 years ago

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Brain tumor resection with open approach
Brain tumor resection with open approach Scott 17,453 Views • 2 years ago

Resection of a glioblastoma multiforme, a very malignant, aggressive brain tumor.

Cutting Circle - Validated Exercise for Laparoscopy in Box Trainer
Cutting Circle - Validated Exercise for Laparoscopy in Box Trainer Scott 10,863 Views • 2 years ago

This task requires cutting a circle from a rubber glove streched over 16 nails in a wooden board. Penalties are calculated when the cutting deviated from the drawn line. Score = time (seconds) + surface of glove in mgs deviated from circle. Performance standard: Score = 189 sec

Direct Puncture Capsulorhexis
Direct Puncture Capsulorhexis DrHouse 11,303 Views • 2 years ago

Direct puncture capsulorhexis with a slightly barbed 30g needle on a TB syringe with BSS permits excellent control even with very high vitreous pressure without use of viscoelastic. Ideal for biaxial (microincision) cataract surgery.

Repair of Pectus Excavatum
Repair of Pectus Excavatum DrPhil 15,401 Views • 2 years ago

Repair techniques for various types of asymmetric pectus excavatum are illustrated. Morphology-tailored bar shaping and selecting the hinge points are key elements of the technique. Repair of two cases on an eccentric type and unbalanced type according to "Park Classification" was demonstrated.

Fibroma Excision in the Cheek
Fibroma Excision in the Cheek Doctor 11,475 Views • 2 years ago

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Thyroidectomy Modern Technique
Thyroidectomy Modern Technique Doctor 41,320 Views • 2 years ago

Modern technique of thyroidectomy for tumors

Funny Check up Trick
Funny Check up Trick Scott 46,959 Views • 2 years ago

very funny medical video..DO NOT TRY AT CLINIC

How the Ear Works?
How the Ear Works? Doctor 17,452 Views • 2 years ago

This animated video reviews how the ear works and some of the typical problems with the ear.

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