Bone Densitometry

As the population ages, osteoporosis has become a common and frequently-occurring disease. Bone density measurement helps to diagnose osteoporosis. Bone mineral density (BMD) is the most effective predictor of fracture risk, and the fracture risk is geometrically related to bone density. Changes in bone mineral density (BMD) can be monitored using a bone densitometer. The orthotopic spine and/or the bilateral femurs are generally used. When the patient's spine has obvious hyperplasia or deformation, bilateral femoral scans are more meaningful. There are six methods for measuring bone density: 1. QCT bone densitometry; 2. Ultrasound bone densitometry; 3. Single photon bone densitometry; 4. Two-photon bone densitometry; 5. X Line bone density meter detection method; 6, dual energy X-ray bone density meter detection method. Basic Information Specialist classification: growth and development check classification: X-ray Applicable gender: whether men and women apply fasting: not fasting Tips: There is no special contraindication before the examination, and the bone density is painless and no damage, and should be relaxed. Normal value Normal bone density is 100%, and a 1%-12% reduction is basically normal. Clinical significance Clinically used to assist in the diagnosis of osteoporosis, a population survey can be conducted to improve the detection rate of osteoporosis. Indications for bone density testing 1. The reduction of bone mass was found on conventional X-ray films, and bone mineral density measurements confirmed this subjective judgment. 2. Necessary examination before starting hormone replacement therapy (HRT). 3. Patients treated with glucocorticoids or patients with Cushing syndrome. 4, patients with primary hyperparathyroidism, necessary examination before surgery. 5, early menopause or menopause, such as anorexia, hunger and so on. 6. Patients after organ transplantation. 7. My mother had a history of fractures. 8, long-term lack of exercise or bedridden patients. 9. Patients with renal dysfunction in order to monitor the effects of excessive parathyroid hormones. 10. Patients with liver disease. 11. Patients with hyperthyroidism or thyroid hormone therapy. 12. Patients with digestive malabsorption syndrome. 13, height dropped more than 4 cm. 14, weight loss of more than 5 kg. 15. Patients with rheumatoid arthritis, even if they do not receive glucocorticoids. Precautions Before the examination: no special contraindications, and the bone density determination is painless, no damage, should relax. Please follow the doctor's instructions when performing the examination. Inspection process Inspection methods and processes: 1. Single photon absorption measurement (SPA): Using the principle that the absorption of radioactive materials by bone tissue is proportional to the bone mineral content, the radioactive isotope is used as a light source to determine the bone mineral content of the human limb bone. Generally, the site of choice is the junction of the distal 1/3 of the humerus and ulna (the middle and lower 1/3 of the forearm) as the measurement point. Generally, the right-handed person measures the left forearm, and the "left-handed" measures the right forearm. This method does not measure the bone density of the hip and midshaft bones (vertebral bones). 2, dual energy X-ray absorptiometry (DEXA): through the X-ray tube ball through a certain device to obtain two kinds of energy, namely low energy and high energy photon peak. After the photon peak penetrates the body, the scanning system sends the received signal to a computer for data processing to obtain the bone mineral content. The instrument can measure the bone volume of any part of the body, with high precision and less harm to the human body. The radiation dose of one part is equal to 1/30 of a chest radiograph and 1% of QCT. 3. Quantitative CT (QCT): For more than 20 years, computerized machine (CT) has been widely used in the field of clinical radiology. QCT can accurately select bone at a specific site to measure bone mineral density, and can evaluate the bone mineral density of the cortical bone. Clinically, fractures caused by osteoporosis are often located in the spine-rich part of the spine, femoral neck, and distal radius. QCT can be used to observe bone mineral changes in these areas. 4, ultrasonic measurement: due to its radiation-free and diagnostic fractures have attracted widespread attention, the use of acoustic wave velocity and amplitude attenuation can reflect the bone mineral content and bone structure and bone strength, and DEXA correlation. Not suitable for the crowd There are no taboos. Adverse reactions and risks Generally no adverse reactions.