## 1 Introduction  
According to the definition of the World Health Organization (WHO, 1994), osteoporosis is a systemic skeletal disease characterized by low bone mass, impaired microarchitecture of bone tissue and, consequently, its increased susceptibility to fractures [1]. It is estimated that osteoporosis affects 22.1% of women and 6.1% of men over the age of 50. Globally, this condition affects approximately 200 million women. In contrast, osteopenia, according to WHO criteria, occurs in 54% of women and 30% of men over the age of 50. The occurrence of osteoporosis is most often associated with age, when disorders of bone tissue remodeling lead to its negative balance. Due to the aging of society, osteoporosis has become a serious civilization disease. The problem has deepened due to the COVID-19 pandemic. The lack of referral of patients for diagnostic tests and the lifestyle that society led during the lockdown contributed significantly to the development of this disease. Lack of physical activity, inappropriate diet, low calcium and phosphorus intake, excessive alcohol consumption, and vitamin D deficiency are risk factors that increase the likelihood of osteoporosis. BMI (Body Mass Index) plays a significant role in assessing the risk of osteoporosis, although it is not a direct indicator of bone mineral density. Low BMI (\(<\)18.5 kg/m\({}^{2}\)) is a risk factor, as it is associated with reduced mechanical loading on bones and deficiencies in vitamin D and calcium, which contribute to bone weakening. On the other hand, high BMI (\(>\)25 kg/m\({}^{2}\)) can have a protective effect, although excess body fat is sometimes linked to negative effects on bone metabolism. BMI is included in fracture risk assessment algorithms, such as FRAX (Fracture Risk Assessment Tool) [2]. In addition to the previously mentioned factors, glucocorticoids used in the treatment of COVID-19 also disrupt bone metabolism and are the third most common cause of osteoporosis, following postmenopausal and senile osteoporosis [3; 4; 5; 6]. Their long-term use increases the risk of fractures, as confirmed by a 2002 study showing nearly a threefold higher risk of vertebral fractures in patients taking these drugs [7; 8]. Considering the above factors, a significant increase in the incidence of osteoporosis should be expected in the coming years. One of the biggest problems associated with this disease is its asymptomatic nature. Osteoporosis is most often diagnosed at an advanced stage, when osteopororetic fractures have already occurred. Osteoporotic fractures are particularly dangerous in the case of the spine, where reduced height and body deformations (e.g., deepening kyphosis) lead to reduced respiratory capacity of the lungs and deterioration of the circulatory and respiratory system, which ultimately results in the patient's death. Currently, the gold standard in osteoporosis diagnostics is bone densitometry (DXA), which consists of bone mineral density (BMD) measurements [9; 10]. The main purpose of this test is to identify patients at particular risk of fractures and to partially monitor the effectiveness of treatment [11]. Bone densitometry is most often performed in the femur and lumbar spine. A significant advantage of bone mineral density measurements in the spine is the high content of trabecular bone, which is where osteopororetic changes appear first [12]. This allows for a relatively accurate determination of the risk of fractures in this location (the most common occur in the L1 vertebra). The results of densitometry, however, can be subject to certain limitations. One of the main issues is the presence of artifacts such as vascular calcifications, osteophytes, or degenerative changes in the spine, which can affect the measurement of bone mineral density (BMD). A particular concern is abdominal aortic calcification, which is often observed in older individuals. This condition can cause artifacts in measurements, leading to results that suggest higher bone density.