CT scanner
A CAT scan or a CT scanner machine is a large machine in the shape of a doughnut. The patient is made to lie on a couch. The couch can slide backwards and forwards. The couch slips into the centre of the doughnut shaped machine which takes the x-ray images around the body. The actual procedure takes anywhere from half an hour to one and half hours. During the CAT scan procedure, the patient's bodily movement has to be minimal and should remain as still and quiet as possible. This significantly helps to increase the clarity of the x ray images.
Some CAT scans need special preparations before hand. The preparation may vary according to the type of scan taken.
For abdominal CT scans, the patient is asked not to eat or drink anything after midnight, the night before the scan. A 'contrast medium' has to be drunk or an injection of 'contrast medium' is administered to the patient. Some of this liquid can be taken at home but more of the liquid is taken in the x ray department before the scan. The contrast medium makes the digestive system show more clearly in the scan. This does not have any side effects.
For CT scans of the head, the patient is given an injection of 'contrast medium' dye beforehand to make the scan clearer.
For CT scans of the chest, the injection of 'contrast medium' dye is administered beforehand to show up the tissues in the area containing cancer or blood vessels more clearly.
For pelvic CT scans, the patient is asked not to eat or drink after midnight of the night before the scan. An injection of 'contrast medium' is given before the scan. An injection of a drug to slow down the movement of the pelvis area is given so that there will be distortion during the time of the scan.
For a rectal scan, the patient is given an enema occasionally. This makes the outline of the bowel stand out more during the scan.
In certain detailed scans of the bowel called virtual colonoscopy, the patient is asked not to eat or drink for 36 hours before the study and two doses of a strong laxative the day before the scan is advised.
Spiral CT Scan
CAT scan technology continues to evolve and promises better quality pictures and patients safety. Newer type of CT scans is known as Spiral or helical CT scan. It is called Spiral scan because the X-ray beam rotates around the patient during the scan in a spiral shape. This helps to give a continuous picture with no possible gaps between the 'slices' of the scan. The 'spiral' or 'helical' CAT scans provide more rapid and accurate visualization of the internal organs. They give more detailed pictures of the organs and tissues including blood vessels. The Spiral CT scans are faster than a normal CT scan. Many trauma centers have started using such scans for more rapid diagnose of internal injuries after serious body trauma.
Anterior Cord Syndrome
Anterior Cord Syndrome refers to the Anterior Spinal Artery Syndrome. The anterior spinal artery originates from the vertebral arteries and basal artery at the base of the brain. It supplies the anterior two thirds of the spinal cord to the upper thoracic, that is chest, region. Anterior cord syndrome results from injury to the motor and sensory pathways in the anterior cord. Patients suffering from Anterior Cord Syndrome may feel some crude sensations, but their movement and more detailed sensation is lost. In Anterior cord syndrome there is damage primarily in the anterior 2/3 cord. This is related to vascular insufficiency, sparing the posterior columns. Anterior cord syndrome usually results from the compression of the artery that runs in front of the spinal cord. The compression may be from bone fragments or a large disc herniation.
In Anterior Spinal cord syndrome, there is usually complete loss of strength below the level of the injury. Anterior spinal artery syndrome produces variable loss of motor function and of sensitivity to pinprick and temperature. Thus the patient undergoes complete sensory loss. But the sensitivity to vibration (vibratory sense) and position sense (proprioception) is preserved.
In Anterior Cord syndrome, the anterior section of the spinal cord is injured. This results in loss of movement and sensory perception. In anterior cord syndrome, there is complete motor paralysis.
In Anterior Cord Syndrome, there is sparing of the dorsal column. The patient therefore exhibits greater motor loss in the legs than arms.
It is interesting to note 80% of spinal cord injuries occur in males. Children suffer spinal cord injuries due to sports activities. Adult suffer spinal cord injuries that are work related.
MRI is a most accurate imaging test for spinal disorders. This is because in MRI the spinal cord parenchyma, soft tissue lesions like hematomas, tumors and interverterbral disks, bony lesions like erosion, hypertrophic changes, collapse, fracture and subluxation are revealed. Myelography with a radiopaque agent is used less often. Physicians normally use CT scans to demonstrate bony fragments compressing the anterior spinal cord. X rays may help to detect bony lesions.
Anterior cord syndrome is said to have the worst prognosis of all cord syndromes. The prognosis is usually good if the recovery is evident and progressive in the patient during first 24 hours. However, if there are no signs of sacral sensibility to pinprick or temperature are present after 24 hours, then the prognosis for functional recovery can be said to be poor. There is no standard course of treatment or cure for anterior cord syndrome. Physicians adopt drug therapies and surgery as part of the treatment program. There have been some exceptional cases where sensations that travel along pathways are still intact after the injury. Normally, it is observed that only 10 to 15% of anterior cord syndrome sufferers demonstrate any improvement in functions over a period of time.
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