Hyperechogenicity of the substantia nigra (SN) in the ``butterfly shaped" midbrain is a widely recognized diagnostic marker to differentiate between the early stages of Parkinsons Disease (PD) and other diseases which cause parkinsonian symptoms. While clinical differentiation of these diseases can be difficult, hyperechogenicity of the SN is only common in PD patients. Transcranial B-mode Ultrasound Imaging (TCUI) has become a heavily relied upon method to detect echogenicity in the brain. While standard B-mode imaging can show the presence of SN hyperechogenicity, it may not be able to do so with high enough specificity for reliably accurate diagnoses. The cutoff of what is considered a normal echogenic size is 0.2cm^2. While harmonic imaging does improve image quality, it suffers from spectral overlap with the noisy fundamental component. Our approach uses an adaptive Third Order Volterra Filter (ToVF), which avoids this problem by completely separating an image into its linear, quadratic, and cubic components with no overlap.