17 October 2008

How healthy are your bones?

In honour of World Osteoporosis Day today, Amy Henderson decided to put her bones to the test and have a Bone Mineral Density scan (BMD). This is what she found out.

In honour of World Osteoporosis Day today, Amy Henderson decided to put her bones to the test and have a Bone Mineral Density scan (BMD). This is what she found out.

Despite the fact that at 28 I am actually a bit young for a BMD scan, my grandmother has osteoporosis and family history of the disease is one of the risk factors.

But where to begin? I started out by contacting the National Osteoporosis Foundation to find out where I could get such a scan done and the Morton and Partners radiologists at the Milnerton Medi-Clinic were kind enough to offer their services.

I had no idea what to expect when I arrived and was thus pleasantly surprised to find out the scan, known as the Dexa Bone Mineral Densitometry scan, is a very simple, non-invasive procedure not unlike going for an X-ray. Elaine Bailey, a radiologist, took me through the steps of the procedure and explained everything as we went along.

Not unlike going for an x-ray
After I had undressed and removed all metal jewellery and clothing with zips or any metal which might interfere with the machine, I was weighed and my height measured. I was then instructed to lie down on a bed with an arm-like structure suspended over the top of the bed which was the scanner.

Bailey went through a list of questions with me which included:

  • Are you left or right handed?
  • Have you had a BMD scan before?
  • Have you had any fractures before?
  • Have you had back surgery?
  • Have you had hip surgery?
  • Have you had a hysterectomy?
  • Have you had oophorectomy?
  • Are you menopausal?
  • Do you have a family history of osteoporosis?
  • Are you on HRT?
  • Are you using fosamax?
  • Do you take calcium?
  • Do you take eltroxin?
  • Do you use cortisone?
  • Are you on any other medication?
  • Do you smoke?
  • Do you exercise?

Since the majority of women who are referred for a BMD scan are perimenopausal or menopausal, Bailey pointed out that it was important for the radiologist to know what kind of medication they are on before they begin the procedure.

The reason for the right/left handed question she said, was because often the hand that is used more will have a stronger bone density.

What is involved in the scan?
Dr Tommy Dicker, who specialises in this field at the Milnerton medi-Clinic, advocates the Dexa method as one of the safest and most reliable ways of measuring bone density and tracking conditions such as osteoporosis.

"Not only is it a very safe and non-invasive procedure, but it's very accurate and the radiation levels are very low," he said.

This is reiterated on RadiologyInfo, a public information website developed and funded by the American College of Radiology (ACR) and the Radiological Society of North America (RSNA).

According to them, Dexa is the method most commonly performed on the lower spine and hips to test for and track osteoporosis and other conditions that cause bone loss. It can also assess an individual’s risk for developing fractures.

They explain that the Dexa machine works by sending a thin, invisible beam of low-dose x-rays with two distinct energy peaks through the bones being examined. One peak is absorbed mainly by soft tissue and the other by bone. The soft tissue amount can be subtracted from the total and what remains is a patient's bone mineral density.

The test results will be in the form of two scores:

  • The T score: This number shows the amount of bone you have compared with a young adult of the same gender with peak bone mass. A score above -1 is considered normal. A score between -1 and -2.5 is classified as osteopenia, the first stage of bone loss. A score below -2.5 is defined as osteoporosis. The T score is used to estimate your risk of developing a fracture.
  • Z score: This number reflects the amount of bone you have compared with other people in your age group and of the same size and gender. If this score is unusually high or low, it may indicate a need for further medical tests.

Quick and painless
After I had answered all the questions, I lay on my back while first my left, then right hip were scanned and then my spine was scanned. My legs were then raised and rested on a block so they were at a 90 degree angle while my hips were scanned together. I then lay on my side as my spine was scanned. All this took about 20 minutes and I felt nothing.

Once this was done I went back to the waiting area while my results were worked out, and then I was called in to speak to Dr Dicker after he had received the results.

I'm very happy to say I passed with flying colours and according to the scan my BMD is perfectly normal for my age, race and gender. The key now however, is to keep it that way. Read here about how to eat right and exercise to prevent osteoporosis.

Prevention better than cure
As happy as I was to hear that everything was in good working order, Dicker did point out that a healthy diet is one of the most important ways to ensure you get adequate calcium intake to protect your bones.

"If you are unsure about whether you're getting enough calcium in your diet or you feel that you might be at risk for osteoporosis, I would strongly recommend you speak to your GP as each case is individual and must be treated as such," he said.

So until I reach menopause I am unlikely to need to go for another BMD scan, but when I do here are some of the things I will need to note:

  • Most radiologists will only see you with a referral from a doctor
  • If you have had a scan before, it helps to take those results along so the doctor can compare the results and see if there is any change in the BMD
  • The average price for a BMD scan is roughly R700, although most medical schemes will cover this.

Sources: RadiologyInfo, www.radiologyinfo.org Morton and Partners Radiologists, Milernton Medi-Clinic, Cape Town.

(Amy Henderson, Health24.com, October 2008)

Read more about the causes and risk factors for osteoporosis:
Osteoporosis and women
Osteoporosis and diet
Osteoporosis and exercise


Read Health24’s Comments Policy

Comment on this story
Comments have been closed for this article.

Ask the Expert

Healthy Bones

Tereza is the CEO of the National Osteoporosis Foundation and worked as a Nursing Sister in the field of Osteoporosis for 18 years prior to her appointment with the Foundation. She used to be the Educational Officer for the Foundation and co-wrote the patient brochure on Osteoporosis. Read more

Still have a question?

Get free advice from our panel of experts

The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical exmanication, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.

* You must accept our condition

Forum Rules