Figure 3b:

Estimating right primary motor cortex (PMC; RPMC) motor neuron (MN) density in patients with sporadic amyotrophic lateral sclerosis (ALS) by using MR imaging. (a) Examples of layer-5 regions of interest from HuR immunostaining of RPMC, digitized at magnification of 20×, from two different patients with ALS. Female patient with sporadic ALS with lower limb onset at 64 years old and 9.9-year disease duration; RPMC mean MN density: 89 neurons per square millimeter in the superior RPMC, 86 neurons per square millimeter in the mid RPMC, 166 neurons per square millimeter in the inferior RPMC (left). Male patient with sporadic ALS patient with lower limb onset at 61 years old and 4-year disease duration; RPMC mean MN density: 178 neurons per square millimeter in the superior RPMC, 174 neurons per square millimeter in the mid RPMC, 170 neurons per square millimeter in the inferior PMC (right). Scale bars, 0.1 mm. (b) Automated RPMC segmentation obtained from Freesurfer (http://surfer.nmr.mgh.harvard.edu/) and normalized white matter volume segmentation from SIENAX (FMRIB Software Library) analyses of T1-weighted MR imaging from the same patients as in a. Normalized volume of RPMC, 0.004; normalized white matter volume, 667 523 mm³ (left). Normalized volume of RPMC, 0.008; normalized white matter volume, 702 866 mm³ (right). (c) Graph shows RPMC mean neuronal density in six patients with sporadic ALS estimated by the following equation: y = (471) + (−10 · rPMC_volume) + (−6 · NWMV) + (0.2 · rPMC_volume · NWMV), where rPMC_volume is normalized volume of RPMC (yielded by Freesurfer) and is multiplied by 10 000 and NWMV is normalized white matter volume yielded by SIENAX divided by 10 000 for ease in visualizing the equation. The dotted line designates perfect prediction.