Lesion classification pipelines for image maximum intensity projection
(MIP) and feature MIP. The top portion illustrates the construction of
the region of interest (ROI) that incorporates volumetric and temporal
information from the four-dimensional dynamic contrast-enhanced MRI
sequence. The same ROI was cropped from the first, second, and third
postcontrast subtraction images and combined in the red, green, and blue
(RGB) channels to form a three-dimensional (3D) RGB ROI. For image MIP
(left branch of the bottom portion), the MIP RGB ROI was generated from
the 3D RGB ROI, collapsing volumetric lesion information at the image
level. For feature MIP (right branch of the bottom portion), volumetric
lesion information was integrated at the feature level by max-pooling
the features extracted from all sections. SVM = support vector machine,
VGG = Visual Geometry Group model.