Henry Anhalt DO FAAP
Ped Eddo

Cranial nerves exam 1st to 7th from the USMLE collection

Removal of pregnancy within the fallopain tube using laparoscopic keyhole surgery. A segment of the tube together with the pregnancy within is removed.

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.

different aging and other skin spots can be treated succesfully with Co2 laser.

Surgical Knot

How to read ECG Part 2:
1-All
2-Myocardial Ischaemia
3-Ectopics, Sinus Pause
4-Atrial Arrhythmias
5-Ventricular Arrhythmia
6-A-V Block

Removal of pregnancy within the fallopain tube using laparoscopic keyhole surgery. A segment of the tube together with the pregnancy within is removed video.

Next to esophagojejunostomy stapling for the reconstruction following total gastrectomy, several silk stitches anchoring the jejunum to endoabdominal fascia are made to restore the function of phrenoesophageal ligament.
anchoring suture reduces the impairment of the anastomotic blood flow that is caused by gravitational tension and so is useful to protect the esophagojejunostomy after total gastrectomy.

On screening colonoscopy, this abnormality was encountered in the cecum. This round worm is Ascaris Lumbricoides, one of the most common human parasites in the world. When ingested, the durable Ascaris eggs hatch in the small intestine releasing larva that migrate through the intestinal wall, and t...ravel both hematogenously and lymphatically to the heart and lungs. Over the next several days, the larva mature in the alveoli, then migrate up the trachea to be swallowed back into the gastrointestinal tract. These larva will then mature in the small bowel; adults couples will succeed in producing an extraordinary number of eggs, over 200,000 ova per day. The adults live one to two years. The majority of Ascaris infections are as in this example asymptomatic. Symptoms are a consequence of either the immunologic hypersensitivity of the host to the worm as in the pulmonary stage referred as Loffler's syndrome or to mechanical obstruction of lumen by the worm. Heavy worm burden can result in intestinal obstruction and migrating worms can cause pancreatitis and/or cholangitis when involving the pancreatobiliary tree. Multiple medical therapies are approved for its treatment including mebendazole. Epidemiologically, infections are most common in areas of lower socio-economic conditions. This man manages a pig farm in China that is used to test pharmaceutical agents. From an endoscopic standpoint it is noteworthy that the worms do not like light and will move away fro the attention it is receiving. In this example, the endoscopist was too slow to snare his prey which succeeded in escaping temporarily into the cooler and darker confines of the small bowel out of reach of the endoscope but not from the soon to be consumed anti-helminthic therapy.

Endoscopic third ventriculostomy in a patient with obstructive hydrocephalus

This video shows how to draw a blood sample which is medically known as venepuncture

Total Laparoscopic Hysterectomy

Bilateral High flex knee replacements for British patient. 81 year old Ken Perris is highly satisfied after double flexible knee replacements in Chennai hospital by Orthopaedic surgeon Dr.A.K.Venkatachalam of www.kneeindia.com. High flex or flexible knee replacements confer the ability to kneel, squat, sit cross legged. Minimally invasive surgical approaches reduce pain and hasten recovery.

Teeth Whitening

Hemostasis after Tooth Extraction

This video depicts how a stent is placed in the coronary artieries. We first place a guiding wire in the heart artery through a catheter, usually from the groin. Then the stent is inflated by a balloon in the artery, which is then removed. The stent remains permanently. Blood thinners, aspirin and plavix, are both required after a stent is placed in your heart artery.

Rhinoplasty Surgery Video

This high technology apparatus for the forearm is helping to restore hand movement in stroke patients. ~ Detroit Medical Center

Its technical name is selective laser trabeculoplasty or SLT. It's a virtually painless, minimally invasive procedure that provides several benefits over conventional treatments for glaucoma. ~ Detroit Medical Center