BMD HIP & SPINE

BMD (Bone Mineral Density) Test Overview

Bone mineral density (BMD) testing, most popularly referred to as a DEXA or DXA scan, is a specialized form of X-ray that focuses on measuring the density and strength of bones. The test is used in the diagnosis of osteoporosis and in determining the likelihood of an individual suffering from fractures. In particular, the hip and spine regions are the main targets of BMD testing since these areas are at high risk of receiving osteoporotic damages. With this type of test, only a small dose of ionizing radiation is used in the imaging of the lower spine and the hips in order to depict images inside the body where bone loss can be present. 

The BMD test has minimal preparation requirements. Most preferentially, patients are recommended to change into loose and light clothes, preferably casual wears, since outfits with zippers, belts or buttons are discouraged. One has to be careful and avoid taking calcium supplements 24 hours before the test. There is typically no food or medication restrictions unless specifically directed by a medical practitioner. 

What is BMD Test? 

The BMD test uses a method which is advanced called Dual-Energy X-ray Absorptiometry (DXA). This involves a specific process of using two X rays but one of them has a higher energy level. Both beams pass alternatively through the bone and the amount absorbed is measured. This test assesses the quantity of bone loss and determines bone strength too. Simply put, if absorption is low, then the osseous . is low and hence could mean risk of osteoporosis. 

Types of BMD Tests: 

Central DXA: 

1. This is a gold standard in diagnosing osteoporosis and it is the most precise, as it estimates BMD at the hip and spine. 

Peripheral DXA (pDXA): 

1. Measures the density of wrist or heel or finger bones. This test is used in case central DXA w9 cannot be done. 

List of Parameters Considered During the BMD Test:

T-score: 

• It considers a comparison of the bone density of a patient with that of a normal adult of 30 years age of the same sex. 
• Interpretations: 
• Above -1: Normal range of bone density. 
• An area between -1 and -2.5: Osteopenia (a condition where bone loss is lesser than osteoporosis). 
• Below -2.5: Osteoporosis. 

 Z-score: 

• This examination provides information on the amount of bone a patient possesses in relation to the amount that is appropriate for their sex, age, and size. 
• It is important in assessing secondary reasons for the occurrence of osteoporosis. 

Reasons for Taking a BMD Test:

• To diagnose the presence of osteoporosis even if the patient has not experienced any fracture. 
• To give an estimation of the chance of the development of future fractures. 
• To follow changes in bone density over time and in response to medications that may have an effect on the skeleton. 
• To evaluate the efficacy of treatments for the condition of osteoporosis. 

Benefits of Taking the Test:

• An easy test does not require the patient to undergo any form of surgical procedure. 
• Can prevent complications and risk associated with the condition, In this case, osteoporosis. 
• The information obtained from the test becomes hand in glove when coupled with information obtained from the BMD test. 
• Patients with a BMD test are likely to be fractures prone and that the stage of disease being suffered from has distorted bone mass. 

Illnesses Diagnosed with a BMD Test:

• Osteoporosis which is a condition in which bones are thin, brittle and weak. 
• Elderly Osteopenia or lower than normal bone mass that precedes the disease osteoporosis. 
• Diseases that are associated with bone loss such as some endocrine abnormalities. 

Preparing for a BMD Test:

• Individuals should wear simple and easy clothes. 
• Appearances should be held where piercings and other metallic items should not be worn. 
• Milk and dairy preparations which are known to be calcium containing chemicals should also be ontaken approximately 24 hours to the planned procedure. 

Pre-requisites: 

• Declaration of all medications taken, as some may change the test results. 
• Informing the technologist of any barium tests or other contrast media that have been performed on the patient recently. 
• Any patient who seeks medical assistance and has discomfort when lying on their back for an extended period should be noted. 

Most Appropriate Period to Conduct BMD Test: 

• In general, the test may be conducted at any time; however, it is best to do it in consultation with a physician bearing in mind a particular time with respect to prescribed medicines or events in life like postpartum or menopause age – life events. 

Eligibility: 

• A woman aged 65 and above and a man aged 70 and above should be included among the recommended persons. 
• Others with risk factors like previous fractures, certain medications, or conditions affecting the skeletal system should also be tested at an earlier age. 

Procedure for Taking a BMD Test: 

• The patient is asked to recline on a table covered with padding as a scanner arm traverses several parts of the body. 
• The individual is instructed to keep very still when the target area is scanned during the test for best possible outcomes. 
• The average length of the test is approximately between 10 minutes and 30 minutes and is painless and easy to endure. 

Cautions Before Test: 

• The necessity of having the test done should be counselled by a medical practitioner first, this applies more to pre-menopausal women and pregnant women. 
• Patients should also be aware of their metal implants, including hip replacements, informing the technician as these will influence the readings.