Dexa p.ppresent
-
Upload
shrikant-tilawat -
Category
Documents
-
view
562 -
download
0
Transcript of Dexa p.ppresent
DEXA Scan to
Detect
Osteoporosis
DEXA scan
Information
Common questions
About DEXA scan
Who should have a DEXA scan?
Preparition for DEXA scan
What happens during a DEXA scan
Use in paediatrics
Interpretion
What are the risks?
What is DEXA Scanning? (About Dexa
Scan )
DEXA scan is an instrument
used to measure the density
of bones. DEXA stands for
dual energy X-ray
absorptiometry. It is now also called
DXA scan. Measurements of bone mineral density are important in many areas of science, but its most important use is found in clinical assessment of osteoporosis (which is a disease in which there is decreased bone mineral density, possibly due to menopause, malnutrition and various other factors).
Who should have a DEXA scan?
• estrogen deficiency in women at clinical risk for osteoporosis
• evidence of vertebral abnormalities
• long term steroid use
• patients with primary hyperparathyroidism
• the need for monitoring to assess response to approved drug therapies for osteoporosis.
• People with Gorhams vanishing bone disease / Lymphangiomatosis
About DEXA scan
Working of the DEXA Scan
In a DEXA scan, the patient is placed
between two sources of X-ray radiation
and a detector. The two sources of X-ray radiation emit
X-rays of different energy levels. These X-rays
penetrate the body depending on the density of the
body tissues i.e. denser tissues do not allow X-rays to
pass through. The X-rays transmitted out on the other
side are detected by an electronic detector, which then
calculates the density of the entire tissue region
between the X-ray source and the detector.
It also calculates the density of specific tissue such as bone by subtracting the other soft tissue absorption value from the source, and hence can gives a clear idea of the bone mineral density. Using two X-ray sources is simply
Preparition 0f DEXA scan
You probably won't need to make any preparations before scan. If the patient usually take medication, continue to take this as usual unless his/her doctor specifically tells no.
• It's best to wear light clothing that doesn't have metal fasteners over y spine or tummy areas. Remove any metal jewellery that wear in navel because this can interfere with the scan of spine.
• A radiographer (a health professional trained to perform imaging procedures) will operate the scanning equipment.
• A DEXA scan isn't recommended for pregnant women, unless there is an urgent medical reason. Please tell your radiographer if you could be pregnant.
Patient may be asked to sign a consent form. This confirms that he understand the benefits, risks and possible alternatives to the procedure and have given his permission for it to go ahead.
What happens during a DEXA scan
The scan usually takes about 10 minutes. Patient
may be asked to remove clothing and put on a
gown.
Patient will be taken to the X-ray room and asked
to lie down on an X-ray table. The radiographer
will operate the scanner from behind a window.
He or she will be able to see, hear and speak to
pt. during the procedure.
What happens during a DEXA
scan
The X-ray machine will slowly pass over your
body and send X-rays through the bones being
tested, usually the hip and lower spine.
A detector will measure how much X-ray radiation
passes through the bones and sends the
information to a computer. It can take as little as
10 seconds to scan each bone - it's important to
lie very still while this is happening.
Current practice in paediatrics
However, it seems that DXA is still in its early days in paediatrics, and there are widely acknowledged limitations and disadvantages with DXA.
Some clinics may routinely carry out DXA scans on paediatric patients with conditions such as nutritional rickets, lupus, and Turner Syndrome. DXA has been demonstrated to measure skeletal maturity and body fat composition and has been used to evaluate the effects of pharmaceutical therapy. It may also aid paediatricians in diagnosing and monitoring treatment of disorders of bone mass acquisition in childhood
How do you interpret the test
results and who is a candidate for
treatment?
• A DEXA scan report
compares the patient's bone
mineral density values with
those of young normal
patient (T score) and with
age matched normal patient
(Z score). By comparing a
patient's bone density
against there peers, a low
score indicates there may
be a reason other than age
related bone loss.
How do you interpret the test
results and who is a candidate for
treatment?
Patients risk factors for osteoporosis that should play a part in the decision to begin treatment include: a maternal history of a hip fracture, any previous fracture after the age of fifty, tall height at age of 25, poor health, some sedatives and anticonvulsant drugs, and the inability to rise from a chair without the use of the arms. The current treatment recommendations are the start of drug therapy to reduce the risk fracture for all women with a bone mineral density T score of less than -2 without other risk factors and for those with a T score of less than -
interpret ion of the test
results
• between 0 and -1 (for example, -0.5), your bone density is normal
• between -1 and -2.5, this is classed as osteopenia - this means bone density is lower than normal, but don't yet have osteoporosis
• below -2.5, this is classed as osteoporosis
• sometimes Z score be given in a scan. This is a measure of how the bone density compares to the average for a person of his own age. This score isn't used to diagnose osteoporosis, but can be used along with age and gender to calculate risk of having a hip fracture in the next 10 years.
What are the risks?
Radiation exposure
Less then the amount of radiation that one receives on an airline flight from Delhi to London and back.
There are a certain group of individuals who should not have the Dexa Scan test. These are
Women who are pregnant or who think they might could be pregnant
Anyone who has had another “contrast x-ray” within the last seven days (examples--upper GI test, CAT scans…)
Anyone who has had a nuclear scan within the last seven days (examples--bone scan, thyroid study…)
What are the risks & benifits
The dexa scan is used to measure bone mineral density as opposed to a regular x-ray or CAT scan for a variety of reasons. First, the dexa scan is extremely accurate; even more so than an x-ray. For bone density loss to show up on a regular x-ray, a person would have to lose 20-30% of their bone mass. Second, the dexa scan requires much less radiation exposure than a CAT scan or “regular” x-ray (Radiographic Absorptiometry). Ironically and interestingly, a person is exposed to more radiation on a “coast-to-coast” airline flight than during a dexascan! Lastly, dexa scans are much less costly than other tests. The current cost (January 2009) for a dexa scan is around Rs.1000/-for W.B. & 400/- for single site,in Govt. institute, it might be worth your while to have this test if your doctor advises it or you are in one of the risk groups listed above.
DEXA SCANNING FANTASTIC
FOR MEASURING B M D
The dexa scan is a fantastic
test for measuring bone
mineral density&body fat
compositin. It is
affordable, painless and
extremely accurate. Most
definitely this is a test worthy of
your time in relation to
osteoporosis diagnosis and
treatment.
PROTECTION IS
ESSENTIAL