| Evaluate lung function is very important to determine serve degree of Lung disease, resectability and predict postoperative lung function. But currently, the standard Lung function tests, including spirometry, plethysmogroply and carbon monoxide-diffusing capacity are performed to determine whole-lung function before and after the therapy .The only means for imaging regional lung ventilation is through a nuclear medicine study But the need to inhale a radioactive substance and poor spatial resolution remain major limitations of this method .Laser -polarized 3He and 129Xe MR imaging have provided detailed imaging of the lung .Although extremely promising ,This modality is limited by the high cost of the laser polarize, The expenses for the noble gases ,and the need for nonproton imaging .Lung abnormality can be found in the CT imaging .But it is difficult to evaluate lung function.Developing of the MRI technique, especial with recent advances of fast MR imaging techniques .MR assessment of lung parenchyma function has become feasible. 1996 year Edelman first reported non-invasion assessment of regional ventilation in the human lung using oxygen-enhanced magnetic resonance imaging. Recently, several investigators have reported that oxygen-enhanced MR Ventilation imaging using IR-SSFSE sequence could obtain good spatial and time resolution lung function imaging and show regional ventilation .There is no report in our country .1.purposeComparing the 11 volunteers signal intensity of lung before and during inhalation pure oxygen, we evaluate an optimal inversion time of IR-SSFSE sequence for oxygen ventilation MR imaging. Study the 31 volunteers signal intensity of lungchange before and during inhalation pure oxygen. Evaluate enhancement effect of signal intensity of the lung during inhalation pure oxygen. Preliminary clinical experience in 5 cases, evaluate the oxygen-enhanced MR ventilation imaging of the lung.2.Material and MethodsEleven volunteers before and during inhalation pure oxygen were examined by MRI using IR-SSFSE sequence in the difference inversion times. Compared the signal intensity of lung before and during inhalation pure oxygen.Thirty-one volunteers during inhalation air and pure oxygen were examined by MRI using IR-SSFSE sequence. TI is 1000 msec which had been proved in previous experiment. Nine cases of 31 volunteers were examined by MR using IR-SSFSE which TI is zero. MR imaging were transferred to a workstation and MR vision software was used for data analysis. Three ROIs were placed on upper-,middle-,and lower-peripheral lung fields. The SI time-course of pure oxygen and air were automatically made by workstation. Measured the signal intensity of lung before and during inhalation pure oxygen, We calculated the oxygen-enhanced percentage rate of lung. Oxygen-enhanced MR ventilation of imaging of the lung were obtained by substract imaging from inhalation of air and pure oxygen. Quantitative T, relaxation time of the lung during breathing of air and pure oxygen. According the f-signal intensity = M0[l-2exp(-TI/T,)]. Statistics using student testing and rank sum test.Five clinical cases during inhalation air and pure oxygen were examined by MRI using IR-SSFSE sequence.. ROI were placed in the central of lesion and normal lung tissue. The SI time-course of pure oxygen and air were automatically. Made by workstation. Calculated the oxygen-enhanced percentage rate of lesion and normal lung tissue before inhalation air and pure oxygen. Subtract imaging from inhalation of air and pure oxygen, evaluated the ventilation function of lesion area and normal lung tissue.3.ResultEleven volunteers during inhalation air and pure oxygen were examined MR using IR-SSFSE in difference TI, the signal intensity of lung were difference and the region of TI 800-1400 msec signal intensity difference is obvious. But TI 1000 mesc was the optimal inversion time for oxygen -enhanced ventilation MR imagingThere were different in the signal intensity of lung during inhalation ai... |
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