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.

This video is a collection of selected cases of Plastic Surgery performed on children with congenital deformities.

Errata: Cleft Lip Case 2 has a center photo which belongs to case 1 at day of surgery.

Cartilage is a slippery tissue that provides a smooth surface for joint motion and acts as a cushion between the bones. Synovium is soft, and it lines the joints. It produces fluid, called synovial fluid, for lubrication, and it supplies nutrients and oxygen to the cartilage. As these functions break down, they no longer protect the bones of the knee joint, and bone damage occurs. OA of the knee can cause pain and stiffness. The symptoms worsen over time

3D ultrasound of IUD in uterus

Herniated or Ruptured Disc: Between each of the vertebre of the spine is a disc which is filled with a gel type material to cushion the connection between the vertebre. With age or injury these intervertebral discs can rupture or herniate. This herniation causes them to push against the adjacent nerves which come from the spinal cord. This can frequently cause pain, numbenss and tingling. This animated video reviews herniated disc.

Dr. David Rivadeneira from Stony Brook University in Stony Brook, NY will host a panel discussion on how to obtain improved outcomes during open surgery through the application of advanced techniques and technologies, including the new LigaSure Impact™ instrument. "It provides excellent and reliable hemostasis on major blood vessels, but the big advancement is that it is faster than traditional techniques and leaves no foreign material behind."

The program will begin with a brief introduction of the topic, followed by video presentation of two procedures, a right hemicolectomy and a sigmoid colectomy. Dr. Rivadeneira will discuss the techniques that he uses. "You'll be able to see the impact of applying multifunctional energy-based instruments to enable rapid and reliable dissection of the mesentery and ligation of colonic blood supply. This is particularly evident on tough diverticular cases, where it works very well with complicated tissue." Joining Dr. Rivadeneira, to review and discuss the cases, will be Dr. Sang Lee from Weill Cornell Medical College, NY.

Laparoscopic Suture Repair of Bowel

Demonstration of subcuticular or intradermal suturing technique for wound closure in the operating room.

Cervical cerclage can be placed via transvaginal, open transabdominal, or laparoscopic transabdominal approach, preferably before pregnancy. Recurrent late miscarriages may be due to a weak (sometimes called an incompetent) cervix that shortens or opens too early in pregnancy. Cervical cerclage involves placing a stitch around the upper part of the cervix to keep it closed; the operation may be carried out through the vagina, or through the abdomen, as an open or laparoscopic ('keyhole') procedure.

Osteoporosis is a disease in which bones become brittle and fragile due to low bone mass and bone tissue loss. It's the most common type of bone disease, according to the National Institutes of Health (NIH), and increases your risk of fractures, particularly of the hips, spine, and wrists. Prevalence In the United States, nearly 54 million people ages 50 and older were living with osteoporosis or osteopenia (low bone mass ) in 2010, according to a 2014 article in the Journal of Bone and Mineral Research. More specifically, 10.2 million adults had osteoporosis, and 43.4 million adults had osteopenia, which puts a person at high risk for osteoporosis.

cardiac massage intermittent compression of the heart by pressure applied either over the sternum (closed cardiac massage) or directly to the heart through an opening in the chest wall (open cardiac massage). simple massage in the nursing interventions classification, a nursing intervention defined as stimulation of the skin and underlying tissues with varying degrees of hand pressure to decrease pain, produce relaxation, and/or improve circulation.

Current treatment is a combination of pegylated interferon-alpha-2a or pegylated interferon-alpha-2b (brand names Pegasys or PEG-Intron) and the antiviral drug ribavirin for a period of 24 or 48 weeks, depending on hepatitis C virus genotype. In a large multicenter randomized control study among genotype 2 or 3 infected patients (NORDymanIC),[35] patients achieving HCV RNA below 1000 IU/mL by day 7 who were treated for 12 weeks demonstrated similar cure rates as those treated for 24 weeks.[36][37]

Pegylated interferon-alpha-2a plus ribavirin may increase sustained virological response among patients with chronic hepatitis C as compared to pegylated interferon-alpha-2b plus ribavirin according to a systematic review of randomized controlled trials .[38] The relative benefit increase was 14.6%. For patients at similar risk to those in this study (41.0% had sustained virological response when not treated with pegylated interferon alpha 2a plus ribavirin), this leads to an absolute benefit increase of 6%. About 16.7 patients must be treated for one to benefit (number needed to treat = 16.7; click here [39] to adjust these results for patients at higher or lower risk of sustained virological response). However, this study's results may be biased due to uncertain temporality of association, selective dose response.

Treatment is generally recommended for patients with proven hepatitis C virus infection and persistently abnormal liver function tests.

Treatment during the acute infection phase has much higher success rates (greater than 90%) with a shorter duration of treatment; however, this must be balanced against the 15-40% chance of spontaneous clearance without treatment (see Acute Hepatitis C section above).

Those with low initial viral loads respond much better to treatment than those with higher viral loads (greater than 400,000 IU/mL). Current combination therapy is usually supervised by physicians in the fields of gastroenterology, hepatology or infectious disease.

The treatment may be physically demanding, particularly for those with a prior history of drug or alcohol abuse. It can qualify for temporary disability in some cases. A substantial proportion of patients will experience a panoply of side effects ranging from a 'flu-like' syndrome (the most common, experienced for a few days after the weekly injection of interferon) to severe adverse events including anemia, cardiovascular events and psychiatric problems such as suicide or suicidal ideation. The latter are exacerbated by the general physiological stress experienced by the patient.

Laparoscopic anterior resection for cancer colon in Qatar by Dr. Al-Emadi

ROTIGS medical device by Honolulu inventor Dr. Brad NaPier makes difficult airway intubations easier for medical professionals.

A Medical Video showing an overview of the endocrine and gland system of the human body

As the liver becomes more severely damaged, more obvious and serious symptoms can develop, such as: yellowing of the skin and whites of the eyes (jaundice) swelling in the legs, ankles and feet, due to a build-up of fluid (oedema)

Patent ductus arteriosus (PDA), in which there is a persistent communication between the descending thoracic aorta and the pulmonary artery that results from failure of normal physiologic closure of the fetal ductus (see image below), is one of the more common congenital heart defects.

Multiple myeloma is a cancer formed by malignant plasma cells. Normal plasma cells are found in the bone marrow and are an important part of the immune system.

Vocal Cord Surgery HD

Anatomy of Anterior Abdominal Wall