Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Magnetic Resonance Imaging


Related Terms

  • MRI
  • Nuclear Magnetic Resonance Imaging

Specialists

  • Radiologist

Comorbid Conditions

Factors Influencing Duration

There are no factors associated with this procedure that would influence disability. Disability may occur as a result of an underlying condition.

Medical Codes

ICD-9-CM:
88.91 - Magnetic Resonance Imaging of Brain and Brain Stem
88.92 - Magnetic Resonance Imaging of Chest and Myocardium; for Evaluation of Hilar and Mediastinal Lymphadenopathy
88.93 - Magnetic Resonance Imaging of Spinal Canal; Spinal Cord Levels: Cervical, Thoracic, Lumbar (Lumbosacral), Spinal Cord, Spine
88.94 - Magnetic Resonance Imaging of Musculoskeletal; Bone Marrow Blood Supply; Extremities (Upper) (Lower)
88.95 - Magnetic Resonance Imaging of Pelvis, Prostate, and Bladder
88.97 - Magnetic Resonance Imaging of Other and Unspecified Sites; Abdomen, Eye Orbit, Face, Neck

Overview

Magnetic resonance imaging (MRI) is a noninvasive diagnostic technique that provides detailed cross-sectional images of organs and structures without the use of x-rays or other radiation.

Each part of the body, on a cellular level, responds differently when exposed to a magnetic field. Therefore, when an individual is surrounded by a magnetic field, a computer can measure the way in which the different parts of the body respond to the magnetic field, resulting in detailed images that can be used for diagnosis of various medical conditions.

MRI is particularly suited to imaging soft tissues. It can assess organ function, can reveal degenerative changes in body structures, and may be used in evaluating the suitability of organs for transplant. MRI is commonly used to reveal tumors throughout the body, examine joints and soft tissues, or evaluate cardiac or brain function. Unlike computed tomography (CT) scans, in which the slices are cross-sectional, MRI can produce slices in any direction throughout the body. MRI is normally considered safe for pregnant women.

Source: Medical Disability Advisor



Reason for Procedure

MRI can be used to reveal tumors throughout the body, indicating their precise location and extent. It can also produce detailed images of the internal structure of the brain, spinal cord, eye, and ear and is useful for examining joints and soft tissues, particularly in the knee and shoulder. It is useful in evaluating the cause of many disorders of uncertain origin, such as seizures, headache, blurred vision, and lower back pain.

In addition to imaging solid structures, MRI protocols have been developed for highlighting fluid flow, allowing investigation of blood vessels (MRI angiography). Evaluation of cardiac function is becoming practical. Some facilities are acquiring the capability for very rapid imaging studies (cine MRI), permitting the study of movements throughout the cardiac cycle.

Although images produced by MRI and those produced by CT scanning are similar in many ways, MRI generally gives a much greater contrast between normal and abnormal tissues. MRI is often used to confirm findings of ultrasound or CT scans. MRI is a valuable diagnostic tool and has a role in selected cases in which other techniques are unreliable. For example, dense breast tissue (as in young women) makes mammography difficult to read. So does scarring, or the presence of silicone implants. In such circumstances, if the woman is at high-risk for breast cancer, MRI may be preferable to traditional mammography.

Source: Medical Disability Advisor



How Procedure is Performed

In MRI, the individual is placed inside a hollow, magnetic tube. Individuals with any metal in their body (implants, pacemakers, metal not removed following an accident or surgery) should inform the doctor and technician before the procedure begins, because some types of metal in the body prevent this procedure from being done.

Once in the MRI tube, the body is exposed to short, pulsed radio waves. In a magnetic field, hydrogen molecules in the body line up parallel to each other. When knocked out of alignment by the strong pulse of radio waves, hydrogen nuclei produce a detectable radio signal as they fall back into alignment. Magnetic coils in the machine detect these signals. They are changed by a computer into an image based on the strength of the signal produced by the different types of tissue. Because the concentration of hydrogen varies in different soft tissues (muscle, fat, fibrous tissue), MRI can differentiate between them. Tissues that contain little or no hydrogen (such as bone) appear as darker images.

In some cases, the contrast of MRI images can be enhanced by means of paramagnetic contrast agents, a substance that can be temporarily magnetized by placing it in a magnetic field. The contrast agent, injected into a vein, is taken up selectively by tissues with more blood vessels. During the MRI procedure, these tissues emit radio waves more readily, increasing the image contrast.

For the individual, most MRI procedures involve lying on a movable table, which is inserted into the opening of the magnet. The part of the body being examined needs to be in the middle of the tube. Although confining, the opening is not overly constrictive. Mild sedation is available for individuals uncomfortable in this position (claustrophobic), as are view mirrors, music, and voice communication with the attending technologists. The procedure may take as little as a few minutes or up to an hour and is characterized by the various rapid, tapping sounds of the MRI scanner acquiring the image. Other than these sounds, the individual perceives nothing, and merely has to lie still until the attendants complete the procedure.

Some newer models of MRI scanners, called open MRI scanners, are less claustrophobic than the normal scanner, but they are not always able to capture the detailed images provided by traditional scanners. If an individual is having a head MRI, he or she may be asked to wear a special magnetic coil around the head. The coil does not touch the individual, and the individual can see through it.

Source: Medical Disability Advisor



Prognosis

MRI imaging provides excellent images for diagnostic purposes. However, it requires a certain level of cooperation from the individual being scanned because the individual must stay still for up to 1 hour.

Source: Medical Disability Advisor



Complications

Some individuals may feel anxious while having the MRI scan performed. Those individuals who have cardiac pacemakers, metal clips that have been applied to vessels to prevent blood clot complications (ferromagnetic aneurysm clips), intrauterine metallic implants, or other metal implants, are contraindicated for MRI scans and may suffer complications if they do undergo MRI scans, since the scanner may interfere with the proper functioning of the ferromagnetic device. Another possible complication is allergy or abnormal reaction to the contrast medium that may be used during some MRI procedures, although that is rare.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

No restrictions or accommodations are anticipated as a result of this procedure.

Source: Medical Disability Advisor



References

General

Davis, Lawrence M., and Lisa Davis. "Magnetic Resonance Imaging (MRI)." eMedicine Health. Eds. Scott Plantz, Francisco Talavera, and Jonathan Adler. 7 Apr. 2004. WebMD, LLC. 21 May 2005 <www.emedicinehealth.com/fulltext/6622.htm>.

Payne, Kattie. "Magnetic Resonance Imaging (MRI)." WebMD.com. Eds. Renée Spengler and Daniel Greer. 17 Jul. 2003. WebMD, LLC. 21 May 2005 <http://my.webmd.com/hw/health_guide_atoz/hw214278.asp?lastselectedguid={5FE84E90-BC77-4056-A91C-9531713CA348}>.

Source: Medical Disability Advisor






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