Automatic Kidney Location Method in Multi-Phase MRI Images

Kidney functional imaging brings a new way for doctors to better understand the function of each kidney. Due to the advantage of no radiation, the study of MRI imaging for kidney GFR (Glomerular Filtration Rate) becomes more and more popular. Automatically locating the kidney region in the MRI images is the first and very important step for the whole analysis flow. Unlike the kidney location in CT images, there are no bones can be the reference to automatically perform the location. Furthermore, there are some disturbing tissues which have the similar intensity with the kidney region in different phase images. This paper proposed a novel method to automatically locating the kidney using the non-contrast scan images and the parenchymal phase images. First, 3D registration and subtraction were employed; then we performed Max Intensity Projection along Anterior-Posterior direction and Head-Foot direction; afterwards, gray morphological method was used to remove some disturbing tissues and at last we used the MID(Max Intensity Distribution) curve to obtain the kidney region boundary. The method was evaluated on 13 data sets including model pigs and patients, and the location results were very good.