Fig 1.
Image processing pipeline describing data collection, pre-processing, segmentation, quality control and information extraction.
(yellow font = software library; DICOM = Digital Imaging and Communications in Medicine; nii = nifti file type; FSL = FMRIB Software Library; ITK-Snap = Insight Segmentation and Registration Toolkit; RF = random forest; HU = Hounsfield Units. ‘CT-scan’ designed using resources from Flatiron.com).
Fig 2.
Examples of semi-automated subarachnoid hemorrhage segmentations for each modified Fisher grade.
(yellow = segmentation overlay, mFS = modified Fisher Scale).
Table 1.
Descriptive information regarding each patient’s demographics, aneurysm, treatment and hospital outcomes.
Fig 3.
Greater segmented blood load is associated with greater radiological vasospasm risk.
Boxplot of blood volume in patients who developed radiological vasospasm (maroon) and those who did not (blue). (*** = p< .001).
Fig 4.
Receiver operating characteristic (ROC) curve demonstrating the performance characteristics of the binary classifier fit in the logistic regression model.
Black = univariate logistic regression model using normalized total blood volume; gray = logistic regression model using dummy-coded modified Fisher score values.
Table 2.
Logistic regression fit parameters for all variables in the full predictive model including confounding variables.
Fig 5.
Associations between subarachnoid blood volume and metrics of severity of radiological vasospasm.
A: Boxplots of blood volume grouped by radiologist’s impression of subjective severity of vasospasm. B: Scatter plot showing the greatest recorded Lindegaard ratio from TCD plotted against normalized blood volume. (* = p < .05, ** = p < .01).
Fig 6.
Associations between subarachnoid blood volume and temporal vasospasm-related outcomes.
A: Scatter plot showing the number of discrete episodes of vasospasm against normalized blood volume. B: Scatter plot showing the duration of vasospasm in days plotted against normalized blood volume. C: Scatter plot showing the total length of hospital stay plotted against normalized blood volume.