Diagnostic Imaging

MOC

What is MOC?

Bone mineral density (BMD ) is a diagnostic test that measures bone mineral density ( BMD ), providing essential information about skeletal health. Based on the bone densitometry technique, bone mineral density (BMD) is the most accurate and reliable method for detecting bone loss.

Why is a DEXA scan done?

The MOC exam is performed for:

Early diagnosis of osteoporosis – It allows us to identify a reduction in bone density before fractures occur.
Fracture risk assessment – Helps estimate the likelihood of osteoporotic fractures, especially in people at risk.
Monitoring over time – It allows you to evaluate the effectiveness of treatments and the evolution of bone health.

Who should undergo a BMD scan?

The test is particularly suitable for:

Postmenopausal women and men over 65 – To detect early osteoporosis related to age or hormonal changes.
People with risk factors – For example, a family history of osteoporosis, previous fractures, prolonged use of corticosteroids, or other pathologies that affect bone health.
Patients being treated for osteoporosis – To monitor the effectiveness of therapies and the evolution of bone density over time.

How do you prepare for the exam?

Preparing for the DEXA exam is very simple. Fasting is not required. A healthcare assistant will assist the patient from the beginning and throughout the exam. You may remain dressed, and you will only need to remove any metal objects (e.g., piercings, necklaces, earrings, rings, etc.).

How is the exam carried out?

During the DEXA scan, the patient is placed on a bed and simply has to remain still for a few minutes. The machine scans specific areas of the body, usually the spine and femur, and provides all the necessary values for bone densitometry.

How long does the MOC exam take?

It has an average total duration of 10-15 minutes, depending on the areas to be analyzed.

What are the risks of BMD?

The test is completely painless and noninvasive. During the procedure, the patient experiences no discomfort. A very low dose of radiation is used, significantly lower than other radiological tests, and it carries no significant risks.

Who can't do the MOC?

DEXA is not recommended for pregnant women, to avoid even minimal radiation exposure. Generally, there are no absolute contraindications, but the evaluation should always be made by a physician based on the patient's clinical condition.

How does MOC work?

The MOC machine consists of a horizontal bed and a movable arm equipped with a low-intensity X-ray source and detector . During the examination, the arm emits beams of X-rays of different energies that pass through the bone and surrounding tissues.

The detector on the opposite side measures how much of the radiation is absorbed by the bone , allowing the computer system to precisely calculate bone mineral density . The data is then processed by dedicated software that provides numerical values (BMD) and related diagnostic indices (T-score and Z-score) , useful for evaluating bone health and identifying any conditions of osteopenia or osteoporosis.

What are the types of MOC?

Currently, two techniques are used for BMD, both based on bone densitometry:

DEXA MOC (Dual-Energy X-ray Absorptiometry): the most common and precise.
MOC peripheral: assesses bone density in the wrist, heel, or other peripheral areas.

DEXA technology is the most widely used today due to its precision. DEXA uses two X-ray beams with different energy levels to analyze bone tissue and accurately measure bone density. Once soft tissue absorption has been ruled out, bone mineral density can be calculated.

The test measures the mineral density of specific areas of the skeleton, such as the lumbar spine, femoral neck, and, more rarely, the forearm or entire body. X-ray absorption varies depending on the amount of minerals present in the bones.

Interpretation of results: T-score and Z-score

The results of the DEXA MOC are expressed through reference parameters to evaluate bone mineral density:

BMD (Bone Mineral Density): It measures the amount of minerals present in the bones. The higher the BMD, the stronger and more resistant the bones are to fractures. A low BMD, however, can indicate more fragile bones and a higher risk of osteoporosis. Measuring BMD is important for preventing bone problems and maintaining good skeletal health.
T-score: It indicates how much the patient's bone density deviates from the ideal value, that is, the peak bone mass reached around age 30. A low T-score may indicate osteopenia or osteoporosis.
Z-score: Compares the patient's bone density to that of other people of the same age, sex, and body size. It is useful for identifying whether bone loss is related to factors other than aging.