Bone densitometry

The bone densitometry is a diagnostic technique that is used to measure the density of calcium in the bones. It is a very common test in adults and the elderly since one of its main uses is to detect osteoporosis early ; in addition, it serves to evaluate how the treatment is working. Densitometry is a very simple test for the patient to perform and, moreover, very fast; It does not even require hospital admission.

X-rays are usually used to carry out this diagnostic test ; Despite the fact that there are currently other more innovative techniques, X-rays are still widely used when performing densitometry.

The test is performed on a single bone, which in the vast majority of cases is the hip, or the lower vertebrae of the spine. In certain cases, densitometry can be performed on the entire body, but it is not the most common.

What is densitometry?

Bone densitometry is a medical test used to evaluate the density of calcium that exists in the bones. That is why it is frequently used to assess the risk of fractures, as well as whether or not the patient has certain bone diseases, such as osteoporosis.

When performing densitometry, two groups of statistical data are taken into account.

• T-score: this parameter indicates the density of calcium that the analyzed bone presents in relation to the maximum amount that the same bone would have under normal conditions. When the score is greater than -1, the result is normal. Meanwhile, if the value ranges between -1 and -2.5, it implies that the patient has a slightly lower bone density than usual. And finally, the patient is considered to have osteoporosis when the score is less than -2.5.
• Z-score: this statistical group includes those parameters that indicate the calcium density of the bone in question compared to the population mean based on various demographic factors: age, sex and BMI. Although they are not determining parameters, abnormal values ​​of the same can lead the doctor to request additional tests.

How long does this test last?

Duration : the bone density test usually lasts between 10 and 30 minutes, depending on the equipment used and the areas to be examined. It’s a pretty quick test.

Who is done with densitometry?

Currently, there is a great debate in the medical field about when it is appropriate to perform this medical test. There are certain population groups for which densitometry is indicated.

• Postmenopause: those women who have already gone through the menopause phase and who do not undergo any hormonal treatment, but who suffer from severe symptoms. Also postmenopausal women who are regular smokers because tobacco significantly accelerates the loss of calcium in the bones.
• Elderly: densitometry is also a test indicated for those elderly people in whose family there is a history of hip fracture.
• Medications: in some cases it is advisable to evaluate the density of calcium present in the bones when people consume medications such as corticosteroids or antiepileptic drugs.
• Alcohol: and, finally, those people who consume alcohol on a regular basis as it favors the loss of calcium in the bones of the body.

Why is densitometry performed?

Densitometry is a diagnostic test that has a large selection of applications.

Osteoporosis

Osteoporosis is a bone disease characterized by a decrease in bone mass density. In this way, the bones become more porous as both the number and the size of the cavities present inside them increases. That is why the bones are more fragile, thus increasing the risk of fracture.

Generally, people reach the maximum amount of bone mass when they are between 30 and 35 years old. From that moment on, there is a progressive loss of it.

Osteoporosis is a disease that affects mainly women , mainly for two reasons. On the one hand, their peak bone mass is lower than that of men. And, on the other hand, menopause dramatically accelerates the loss of bone mass.

Imperfect osteogenesis

Osteogenesis imperfecta is a genetic disease characterized by the fact that the bones are very fragile , so that they fracture very easily. The first symptoms appear in childhood, and can be very varied: weakness in the muscles, a deviated spine …

The severity with which this disease occurs varies significantly from one person to another. In some cases, there are just a few fractures in a lifetime, while other people have several dozen of them.

Multiple myeloma

A malignant tumor that begins in plasma cells , which form a very important part of the immune system. As the disease progresses, the myeloma cells clump together in the bone marrow, as well as in the more solid areas of the bone.

It is a disease that mainly affects older people and whose main symptoms are the following: pain of varying intensity in the bones, frequent fractures, weakness for no apparent reason, and fever .

Kidney disease

Certain kidney diseases can also lead to loss of bone mass, which may lead the doctor to request a densitometry. These types of disorders mean that the kidneys are damaged in some way, so that they cannot filter the blood properly . A condition that can lead to waste build-up in the body, thus leading to potentially serious health problems.

Liver disease

The liver is the largest organ in the body, and it fulfills very important functions for the proper functioning of the body. There are a wide range of disorders that may result in a loss of bone mass, such as the hepatitis , the cirrhosis or hemochromatosis.

How is densitometry performed?

As we have commented before, the duration of the densitometry is quite short. It is a very simple medical test that is performed in just 15 – 30 minutes, which does not require hospital admission; it is carried out on an outpatient basis . It is painless, so it is very comfortable for the patient.

In this case, the patient can go to the clinic with total normality; it is not necessary to go on an empty stomach. In relation to medications, it is important to inform the doctor of all those that are previously consumed; in case of taking calcium supplements, they should not be ingested 24 hours before the densitometry begins.

Process

When the patient goes to the clinic where the test is to be performed, they should first wear a dressing gown to make it easier for the doctor to proceed with the bone densitometry.

It should then be placed on the stretcher in the position indicated by the doctor depending on the bone on which the test is to be performed. For example, if you want to measure the bone density of the spine, the legs should be higher, so that the back is fully supported on the table.

The doctor then proceeds with the test, taking a series of X – rays . A totally painless procedure for the patient. After a few minutes, the doctor communicates that the densitometry has finished.

Complications

The complications of bone densitometry hardly exist since it is a painless and non-invasive test for the patient . However, when using X-rays for your procedure, there is always a certain risk, before which a series of basic precautions must be taken. It must be taken into account that the radiation dose is infinitely lower than that of routine X-ray tests.

In this way, unlike the usual radiological tests, it is not necessary for the patient to wear lead protectors to protect sensitive organs such as the genitals or the ovaries.

Conclution

Currently, it is estimated that osteoporosis is a disease that affects around three million people in Spain , especially those over 50 years of age. In addition, as experts point out, 33% of women and 17% of men will suffer a fracture due to osteoporosis.

In these cases, densitometry is a key radiological test to diagnose this condition. Thus, based on the density of calcium present in the bone, the doctor can estimate the risk of suffering from osteoporosis. Similarly, densitometry is recommended in those patients with osteoporosis who are undergoing treatment for this disease, so that the doctor can evaluate its effectiveness.

In short, the main objective of densitometry is to help prevent bone fractures through prevention in relation to lifestyle, as well as the prescription of the corresponding medical treatment when necessary