99Tcm-DTPA lung epithelial cell permeability assay

The 99Tcm-DTPA lung epithelial cell permeability assay is used to understand the permeability of alveolar epithelial cells and capillary endothelium. The inner diameter of the alveolar capillaries averages 8m. When the radioactive particles (99mTc-MAA) with a diameter of 10-60m are injected, the particles enter the pulmonary vascular bed with the blood flow, and are once incarcerated in the pulmonary capillaries or pulmonary arterioles. The distribution was proportional to local pulmonary blood flow (r=0.97). Basic Information Specialist Category: Respiratory Examination Category: Radionuclide Applicable gender: whether men and women apply fasting: not fasting Tips: Pay attention to normal eating habits before check, pay attention to personal hygiene. Normal value When the alveolar epithelium is normal, the clearance curve is a single-phase exponential curve. The normal reference value depends on the situation of each hospital. It has been reported in the literature that the average half-clearance time of 99mTc-DTPA is 86 +/- 26 min. Clinical significance Understand the effects of lung disease on the permeability of lung epithelial cells. It can be used for the assessment of lung epithelial permeability in patients with acute lung injury, such as hyaline membrane disease and adult respiratory distress syndrome. The early stage of the lesion can be accelerated by 99Tcm-DTPA, C1/2 is shortened, and C1/2 can be improved after the condition is improved. Gradually returned to normal. It is worth noting that other lung diseases, such as acute interstitial pneumonia and idiopathic pulmonary fibrosis, which cause changes in the integrity of alveolar epithelial cells, can also be obtained. Therefore, the permeability of lung epithelial cells is determined. Can be used for efficacy observation, but can not be a clear diagnosis of lung disease. Abnormal results: reduced or defective limitations. 1. One side of the lung is not developed; 2. Lung leaf abnormality; 3. Lung segmental abnormality; 4. Diffuse abnormality; Radioactive distribution reverses the tip of the lung above the bottom of the lung, which is caused by pulmonary hypertension. People who need to be examined: suspected pulmonary vascular disease, such as PTE, pulmonary inflammation, etc.; chronic obstructive pulmonary disease; tumor and other symptoms of compression of the pulmonary artery and other symptoms. Low results may be diseases: chronic obstructive pulmonary disease, pulmonary stenosis considerations Forbidden before examination: Pay attention to normal eating habits and pay attention to personal hygiene. Requirements for examination: actively cooperate with the doctor, oxygen for 10 ~ 15min; whether there is pulmonary hypertension, the choice of sitting position (good lung expansion) injection is appropriate; MAA before injection, shake, slow injection, avoid pumping back blood; there are right to left shunt patients Use with caution; patients with severe pulmonary hypertension and extreme damage to the pulmonary vascular bed; children and lung resection patients reduced; negative reactions are rare, timely inhalation of oxygen and symptoms disappear after rest. Inspection process Principle: The inner diameter of alveolar capillaries is 8m on average. When radioactive particles (99mTc-MAA) with a diameter of 10-60m are injected, the particles enter the pulmonary vascular bed with blood flow, and are incarcerated in the pulmonary capillaries or pulmonary arterioles. Within, its distribution is proportional to local pulmonary blood flow (r = 0.97). By using a nuclear medicine imaging apparatus to photograph in vitro, an image reflecting local pulmonary blood perfusion can be obtained, so it is called lung perfusion imaging. Imaging agent: 99mTc-MAA (large particle polymerized human serum albumin) suspension. Supine position slow (about 1min) intravenous injection, avoid pumping back blood (anti-particle aggregation). Multi-body planar imaging (ANT, POST, RLA, LLA, LAO, RAO, LPO, RPO) or / and tomographic imaging. Not suitable for the crowd Inappropriate crowd: No. Adverse reactions and risks Nothing.