Pohjonen H K, Savolainen S E, Nikkinen P H, Poutanen V P, Korppi-Tommola E T, Liewendahl B K
Medical Engineering Centre, Helsinki University Central Hospital, Finland.
Ann Nucl Med. 1996 Nov;10(4):409-17. doi: 10.1007/BF03164802.
The importance of applying MRI (CT)/SPECT fusion in the abdominal and thoracic areas has been recognized in recent studies aiming at radionuclide therapy of cancer. According to our earlier results spleen and liver volume determination with different segmentation methods is inaccurate with SPECT alone. We therefore applied a SPECT/MRI registration procedure to the estimation of spleen and liver volumes and spleen/liver activity ratios in three male volunteers administered 111In-labeled thrombocytes and 99mTc-labeled colloids. The objectives of the study were to investigate if the uptake of thrombocytes in the spleen and liver can be measured more accurately when the anatomical borders of these organs are transferred from MRI to SPECT, and to test a SPECT/MRI registration method for improving three-dimensional dosimetry for radiotherapy treatment planning. A good correlation was found between spleen/liver activity ratios calculated from volumetric average activity per pixel values and from total volumetric counts derived from registered data but not from projection data. The average registration residual with this SPECT/MRI fusion method is approximately 1-2 cm in the abdominal area. Combining anatomical images with SPECT is therefore important for improving quantitative SPECT also in the abdomen.
在针对癌症放射性核素治疗的近期研究中，已认识到在腹部和胸部应用MRI（CT）/SPECT融合技术的重要性。根据我们早期的结果，仅使用SPECT通过不同分割方法测定脾脏和肝脏体积是不准确的。因此，我们将SPECT/MRI配准程序应用于三名接受111In标记血小板和99mTc标记胶体的男性志愿者的脾脏和肝脏体积以及脾脏/肝脏活性比的估算。该研究的目的是调查当这些器官的解剖边界从MRI转移到SPECT时，脾脏和肝脏中血小板的摄取是否能更准确地测量，并测试一种SPECT/MRI配准方法以改善放射治疗治疗计划的三维剂量测定。从每个像素值的体积平均活性计算得出的脾脏/肝脏活性比与从配准数据而非投影数据得出的总体积计数之间发现了良好的相关性。使用这种SPECT/MRI融合方法的平均配准残余在腹部区域约为1 - 2厘米。因此，将解剖图像与SPECT相结合对于改善腹部的定量SPECT也很重要。
