What Is a Three-Phase Bone Scan?
Commonly known as "bone imaging", one of the common inspection items in nuclear medicine. An isotope whole body bone scan is a radionuclide to detect morphological or metabolic abnormalities of bone tissue. Bone imaging includes whole bone imaging, local bone plane imaging, bone three-phase imaging, bone tomography, bone SPECT / CT imaging, and F18 (fluorine) positron bone imaging.
- Chinese name
- Bone scan
- Commonly known
- "Bone Imaging"
- Detection
- Morphological or metabolic abnormalities of bone tissue
- Classification
- Whole bone imaging
- Features
- First inject radiopharmaceuticals (bone imaging agents)
- Use
- Early detection of bone metastatic tumors, etc.
- Commonly known as "bone imaging", one of the common inspection items in nuclear medicine. An isotope whole body bone scan is a radionuclide to detect morphological or metabolic abnormalities of bone tissue. Bone imaging includes whole bone imaging, local bone plane imaging, bone three-phase imaging, bone tomography, bone SPECT / CT imaging, and F18 (fluorine) positron bone imaging.
Bone scan
- Bone scan is a kind of nuclear medicine imaging examination of whole body bones. It differs from X-ray imaging of local bones in that a radiopharmaceutical (bone imaging agent) is injected before the examination, and the bone is generally absorbed. Generally, 2 3 hours later, use radiological imaging equipment (such as gamma camera, ECT) to detect the radiological distribution of bones throughout the body. If the absorption of radioactivity increases or decreases in some bones, there will be abnormal radioactivity concentration or sparseness. Abnormal bone radioactivity absorption during a bone scan is a reflection of abnormal bone metabolism. Therefore, the bone scan is earlier than the lesion found by X-ray examination, which can be as early as 3 to 6 months.
Bone Scan Clinical Application
- 2. The uptake of bone imaging agents (radioactive drugs) in malignant primary bone tumors is higher than that in normal tissues or benign bone tumors. In the three-phase imaging of bone, the arterial phase may have early filling, and the blood pool phase presents local congestion and delayed phase. Appeared as abnormal concentration of local radioactivity. Osteosarcoma, Ewing's sarcoma, and chondrosarcoma are the most malignant primary malignant bone tumors. Bone imaging has a high diagnostic value, but what type of tumor is clinically combined with age, lesion location, number of lesions, and morphology of the imaging map. Extra-bone metastases (usually lung metastases) of certain primary bone tumors can also concentrate bone imaging agents. Bone imaging is far more sensitive than x-ray diagnosis in the diagnosis of osteosarcoma lung metastases. For primary bone tumors, such as multiple myeloma, with osteolytic changes, the uptake of imaging agents by the diseased tissue does not increase significantly, so the diagnostic sensitivity is not as good as the X-ray examination. In general, bone imaging shows a larger range of lesions than X-rays. For diagnosed primary bone tumors, bone imaging can show the range of abnormal bone metabolism, which is helpful for the formulation of surgical plans. The size of the irradiation field and the reasonable effect of the treatment are estimated.
- 3. Fractures Most fractures are diagnosed with X-rays and do not require bone imaging. However, for small fractures of the spine, toes, wrists, sacrum, sternum, and scapula, X-rays are sometimes difficult to find, and bone imaging at this time has diagnostic value. Stress fracture is a fracture caused by multiple overloaded exercises. Also known as marching fractures or fatigue fractures, similar to minor fractures, they occur at a high rate during recruit training and long marches. If you do not rest in time and continue to increase the load, you may exacerbate minor fractures into obvious fractures. X-rays can not find abnormal bone fracture lines, and in bone delayed imaging, oval or spindle-shaped radioactive concentrations can be found in painful areas. If bone imaging does not show such abnormal concentrations, Exclude stress fractures.
- 4. Aseptic necrosis fracture and dislocation can damage the blood supply of bone and cause aseptic necrosis. The femoral head is the most common site of ischemic aseptic necrosis. In the early stage of necrosis, the radioactivity of the femoral head area on the affected side is reduced. As the femoral head wears, the hips become white, stimulating blood vessel reconstruction, and the radionuclide uptake increases. "Circle" -like changes, that is, the radioactivity in the central area is reduced and the surrounding radioactivity is enhanced. In the later period, due to the more severe white wear of the hip, the radioactive focus is more obvious, so that the radioactivity of the femoral head necrosis is reduced, but the tomography can still see the "fried circle" Sign. It is generally considered that three-phase imaging of bone is more sensitive than simple delayed imaging. In the early stage of aseptic necrosis of the femoral head, local arterial perfusion phase reduction and blood pool phase venous return disorder can be seen.
- 5. Bone graft monitoring bone imaging has unique value for judging whether the graft bone is alive. After bone transplantation, the response to soft tissue injury diminishes. If the local bone imaging shows that the radioactivity at the transplanted bone is similar to or higher than that of normal bone tissue, it indicates good blood flow and bone graft survival.
- Bone imaging is often used in the following cases: (1) early diagnosis of primary bone tumors and soft tissue and lung metastases of bone tumors; (2) examination of bone pain of unknown cause; (3) selection of histological examination of bone pathology; ( 4) Formulate radiotherapy plan; (6) Screen patients with suspicious tumors; (7) Diagnosis and follow-up of skeletal inflammatory lesions; (8) Differential diagnosis of bone and joint trauma such as stress fractures and ischemic osteonecrosis; (9) ) Localized diagnosis of Paget's disease and follow-up after treatment.
- Commonly used bone imaging agent 99mTc-methylene bisphosphonate (99mTc-MDP). The dose is 740-1110MBq (20-30mCi).
Bone scan medical significance
- Bone scan can detect bone metastatic tumors early, so for patients with unknown masses, the presence of bone metastatic tumors means that the tumors are malignant, that is, they have metastasized to the bones. For patients who have been identified as cancer, it is helpful to clinically stage the cancer, that is, to determine whether it is early or late, so that the doctor can decide which treatment method to use, whether it is local surgery, radiotherapy, or systemic chemotherapy. Is it necessary to eradicate it extensively? Treated cancer patients can observe bone metastases and changes in the degree of bone metastases by regularly repeating bone scans (with an interval of 3 months to 1 year) to monitor the efficacy of treatment and tumor recurrence. Bone scan can determine whether the pain is caused by arthritis or para-articular osteopathic disease, osteoarthritis or visceral and neuropathic pain, can diagnose various metabolic bone and joint diseases, and diagnose osteomyelitis early in the inflammation of soft tissue of the limb It can find small fractures in some special parts, such as the sacrum, ribs, etc., observe the blood supply and survival of the transplanted bone, and evaluate the effect of the above-mentioned treatment of various benign and malignant bone diseases. Therefore, bone scan is a routine examination item in cancer patients abroad, and it is also the most important examination item in nuclear medicine department in large domestic general hospitals.
Bone scan
- Isotope whole body bone scan
- Preoperative bone scan
- (1) Early diagnosis of primary bone tumors and soft tissue and lung metastases of bone tumors;
- (2) Examine bone pain of unknown cause;
- (3) Select the histological examination site of bone pathology;
- (4) Formulate radiotherapy plans;
- (5) Preoperative staging of lymphoma, breast cancer, lung cancer, prostate cancer and other system tumors and follow-up after treatment;
- (6) Screening patients with suspicious tumors;
- (7) Diagnosis and follow-up of skeletal inflammatory lesions;
- (8) Differential diagnosis of bone and joint trauma such as stress fracture and ischemic osteonecrosis;
- (9) Localized diagnosis of Paget disease and follow-up after treatment.
CT The difference between bone scan and CT
- Nuclear medicine imaging diagnosis ECT (also known as SPECT) and CT are quite different. In nuclear medicine examinations, drugs are injected first, and the radioactivity of the drugs is used for imaging. CT is a machine that emits X-rays to penetrate the human body for imaging! There is a machine called SPECT / CT that does both together, and the images come out and then merge! This kind of examination is very harmless to the body, so don't worry, it is usually okay after the medicine decays in about one day.
- CT is radiological and ECT is nuclear medicine. Radiation is looking at lesions from anatomy, while nuclear medicine is looking at lesions from a functional perspective. If it is best to do SPECT / CT, when doing ECT, if the staff finds that you have suspicious lesions, they will do CT, so that ECT and CT are done together, the position is unchanged, and then the fusion process will be more clear. Your lesion is gone. And it costs less than the sum of CT and ECT.