Purpose
To assess the performance of computer extracted feature analysis of dynamic contrast enhanced (DCE) magnetic resonance images (MRI) of axillary lymph nodes. To determine which quantitative features best predict nodal metastasis.
Methods
This institutional board-approved HIPAA compliant study, in which informed patient consent was waived, collected enhanced T1 images of the axilla from patients with breast cancer. Lesion segmentation and feature analysis were performed on 192 nodes using a laboratory-developed quantitative image analysis (QIA) workstation. The importances of 28 features were assessed. Classification used the features as input to a neural net classifier in a leave-one-case-out cross-validation and evaluated with receiver operating characteristic (ROC) analysis.
Results
The area under the ROC curve (AUC) values for features in the task of distinguishing between positive and negative nodes ranged from just over 0.50 to 0.70. Five features yielded AUCs greater than 0.65: two morphological and three textural features. In cross-validation, the neural net classifier obtained an AUC of 0.88 (SE 0.03) for the task of distinguishing between positive and negative nodes.
Conclusion
QIA of DCE MRI demonstrated promising performance in discriminating between positive and negative axillary nodes.
is assumed that also in non-erythrocytes the membrane skeleton is mostly composed of heterotetramers of a-II and b-II spectrin. Because of a-spectrins' potential role as mechanotransducers, we investigate the effect of mechanical stimulation on the spectrin-ankyrin B membrane skeleton of NIH 3T3 fibroblasts and murine C3H 10T½ cells. Using quantitative fluorescence microscopy and biochemical techniques, the absolute changes in cellular spectrin and ankyrin B content were determined. Before stimulation the spectrins and ankyrin B make up more than 10% of cytosolic and membrane proteins. Thus, they constitute a much more significant part of the non-erythroid cytoskeleton in these cells than previously assumed. Interestingly, both cell types contain all four major isoforms of spectrin. However, while a-II spectrin is the dominant a spectrin in 3T3, in 10T½ cells it is the 'erythroid' a-I spectrin. Also, at least half of the a spectrins do not have b-spectrin counterparts and thus cannot be part of the classical heterotetramere structure. Mechanical stimulation decreases the overall spectrin amount by up to 60% with a-spectrins exhibiting the largest loss. In contrast, the number of ankyrin B copies increases by almost 30%. Furthermore, the fraction of polyubiquitinated spectrin actually increases, which in part could account for the reduction in a-spectrins and is in line with their proposed mechanically enhanced selfubiquitination activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.