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new fundus camera for examining the retina without dilating the pupil

Pediatric Lumbar puncture

Epidermoid cysts, also called sebaceous, keratin, or epithelial cysts, are small, hard lumps that develop under the skin. These cysts are common. They grow slowly. They do not cause other symptoms and are nearly never cancerous. Epidermoid cysts are often found on the face, head, neck, back, or genitals

Anorectal malformations are defects that occur during the fifth to seventh weeks of fetal development. With these defects, the anus (opening at the end of the large intestine through which stool passes) and the rectum (area of the large intestine just above the anus) do not develop properly

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.

Watch that video of Pathway and Ejaculation of Sperm

Thigh pain is most often caused by injuries to bones, joints, muscles, tendons, ligaments, and other soft tissues or blood vessels. These injuries are often caused during sports competition, or strain from overuse, obesity, or pregnancy.

Medical examination of the abdomen from Loyola University, Chicago

A video showing the total thyroidectomy operation

Hypercalcemia is a condition in which the calcium level in your blood is above normal. Too much calcium in your blood can weaken your bones, create kidney stones, and interfere with the way your heart and brain works. Hypercalcemia most commonly results from overactive parathyroid glands. These four tiny glands are each about the size of a grain of rice and are located on or near the thyroid gland. Other causes of hypercalcemia include cancer, certain other medical disorders, some medications, and excessive use of calcium and vitamin D supplements. Signs and symptoms of hypercalcemia may range from nonexistent to severe. Treatment depends on the underlying cause.

Retinitis pigmentosa is a rare, inherited degenerative eye disease that causes severe vision impairment. Symptoms often begin in childhood. They include decreased vision at night or in low light and loss of side vision (tunnel vision).

The Human Body in Numbers.

Bartholin gland Marsupialization in Primary Bartholin Cyst

A positive Speed's test result is usually thought to suggest inflammation or lesions related to the biceps/labral complex. The specificity, sensitivity, and positive and negative predictive values are determined for the Speed's test.

Intrauterine insemination (IUI) is a fertility treatment that involves placing sperm inside a woman's uterus to facilitate fertilization. The goal of IUI is to increase the number of sperm that reach the fallopian tubes and subsequently increase the chance of fertilization.

Osteochondral Allograft

Sialadenitis is an infection of the salivary glands. It is usually caused by a virus or bacteria . The parotid (in front of the ear) and submandibular (under the chin) glands are most commonly affected. Sialadenitis may be associated with pain, tenderness, redness, and gradual, localized swelling of the affected area.

Tracheotomy is a surgical procedure which consists of making an incision on the anterior aspect of the neck and opening a direct airway through an incision in the trachea (windpipe). The resulting stoma (hole), or tracheostomy, can serve independently as an airway or as a site for a tracheostomy tube to be inserted; this tube allows a person to breathe without the use of his or her nose or mouth. Both surgical and percutaneous techniques are widely used in current surgical practice. It is among the oldest described procedures.

ICDs are useful in preventing sudden death in patients with known, sustained ventricular tachycardia or fibrillation. Studies have shown ICDs to have a role in preventing cardiac arrest in high-risk patients who haven't had, but are at risk for, life-threatening ventricular arrhythmias. View an animation of an ICD. Newer-generation ICDs may have a dual function which includes the ability to serve as a pacemaker. The pacemaker feature would stimulate the heart to beat if the heart rate is detected to be too slow. What is an Implantable Cardioverter Defibrillator (ICD)? An ICD is a battery-powered device placed under the skin that keeps track of your heart rate. Thin wires connect the ICD to your heart. If an abnormal heart rhythm is detected the device will deliver an electric shock to restore a normal heartbeat if your heart is beating chaotically and much too fast. ICDs have been very useful in preventing sudden death in patients with known, sustained ventricular tachycardia or fibrillation. Studies have shown that they may have a role in preventing cardiac arrest in high-risk patients who haven't had, but are at risk for, life-threatening ventricular arrhythmias.