# Conventional and Deep Learning Methods for Skull Stripping in Brain MRI
## 3 Classical or Conventional Skull Stripping Approaches
### Meta-Algorithms and Hybrid Methods
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Classical Methods** & **Authors** & **Year** & **Methods** & **Dataset** & **Performance Measures** \\ \hline \multirow{4}{*}{\begin{tabular}{c} Histogram Thresholding and Morphology-based Methods \\ Methods \\ \end{tabular} } & [PERSON] et al. [50] & 2001 & BSE & T\({}_{1}\)W & Jaccard, Dice Coefficient \\  & [PERSON] et al. [45] & 2002 & HRBS & T\({}_{1}\)W & Jaccard, Dice Coefficient \\  & [PERSON] et al. [46] & 2012 & SMILES & T\({}_{1}\)W & [PERSON], Dice, Sensitivity, Specificity \\  & [PERSON] and & 2010,2011 & BEA & T\({}_{1}\)W and T\({}_{2}\)W & [PERSON], Dice, Sensitivity, Specificity \\  & [PERSON] et al. [54] & 2012 & HEAD & T\({}_{1}\)W & [PERSON], Dice, Sensitivity, Specificity \\  & [PERSON] et al. [55] & 2007 & SMSS & Adult and infant T\({}_{1}\)W T\({}_{2}\)W & Dice Coefficient \\ \hline \multirow{4}{*}{\begin{tabular}{c} Median Thresholding and Morphology-based Methods \\ Methods \\ \end{tabular} } & [PERSON], [PERSON] M [25] & 2002 & BET & T\({}_{1}\)W and T\({}_{2}\)W & Mean \(\uparrow\) error formulation \\  & [PERSON] et al. [64] & 2006 & MLS & T\({}_{1}\)W (Induding Pediatric) & Jaccard, Dice, Sensitivity, Specificity, False Positive Rate \\  & [PERSON] et al. [64] & 2019 & Improved BET & T\({}_{1}\)W & Distance (ASSI), maximum symmetric surface distance \\  & [PERSON] et al. [63] & 2009 & RBFs & T\({}_{1}\)W & Jaccard, Sensitivity, Specificity and Extraction Risk \\  & [PERSON] et al. [69] & 2004 & HWA & T\({}_{1}\)W & Jaccard, Risk Evaluation \\  & [PERSON] et al. [107] & 2014 & optBT & T\({}_{1}\)W & Median Sum of Square and Name \\ \hline \multirow{4}{*}{\begin{tabular}{c} Atlas or library-based Methods \\ \end{tabular} } & [PERSON] et al. [67] & 2010 & MATS & T\({}_{1}\)W & Jaccard, Jaccard, \\  & [PERSON] et al. [70] & 2012 & BEAST & T\({}_{1}\)W, T\({}_{2}\)W, and PDW & Dice, False Positive Rate (FPF) and False Negative Rate (PNR), leave-one-out-out-validation (LOOV) \\  & [PERSON] et al. [81] & 2017 & MONSTR & T\({}_{1}\)W, T\({}_{2}\)W Including Tumor & Dice, ASSD, LOOV, Percent of erroneous boundary voxels \\  & [PERSON] et al. [68] & 2015 & _Precomm_ & T\({}_{1}\)W & [PERSON], Volume error, Sensitivity, ASSD \\  & [PERSON] et al. [78] & 2016 & MAIS & T\({}_{1}\)W, T\({}_{2}\)W & Dice, Absolute and Percent Volume Differences, Intraclass \\  & [PERSON] et al. [80] & 2016 & ALFA & T\({}_{1}\)W, T\({}_{2}\)W (noncital) & Dice, HDL Sensitivity, Specificity \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} Region Growing Methods \\ \end{tabular} } & [PERSON] et al. [83] & 1992 & Semi-automated & MRI and CT & Visual inspection \\  & [PERSON] et al. [84] & 1997 & 30 SBG & MRI and clinical short-axis cardiac & \\  & [PERSON] [86] & 2009 & 22 DRG & T\({}_{1}\)W & Jaccard, Dice, Sensitivity, Specificity \\  & [PERSON] et al. [80] & 2014 & 22 DRG (MARGA) & T\({}_{1}\)W, T\({}_{2}\)W & Dice \\  & [PERSON] et al. [69] & 2004 & HWA & T\({}_{1}\)W & Jaccard, Dice, Sensitivity, Specificity \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Meta-algorithms and \\ Hybrid Methods \\ \end{tabular} } & [PERSON] et al. [94; 2013, 2012] & aic:StepTismageFilter & T\({}_{1}\)W, T\({}_{2}\)W, and CT & Dice, extractor error \\  & [PERSON] et al. [96] & 2004 & BEA & T\({}_{1}\)W & Dice, Sensitivity, Specificity, HDL, SSSD \\ \cline{1-1}  & [PERSON] et al. [99] & 2011 & ROREX & T\({}_{1}\)W & [PERSON], Sensitivity, Specificity, HDL, SSSD \\ \cline{1-1}  & [PERSON] et al. [101] & 2011 & Modified ROREX & T\({}_{1}\)W (GBM) & Dice, SSSD \\ \cline{1-1}  & [PERSON] et al. [100] & 2011 & SPECTRE & T\({}_{1}\)W & Dice, Containment Index (CT), paired t-test \\ \cline{1-1}  & [PERSON] et al. [101] & 2012 & LABEL & T\({}_{1}\)W, T\({}_{2}\)W (Noncate) & [PERSON], FPR, FN, mean projection map \\ \cline{1-1}  & [PERSON] et al. [69] & 2004 & HWA & T\({}_{1}\)[PERSON] & [PERSON], Risk Evaluation \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Notable conventional skull stripping algorithms.