Improved CT Detection of Acute Herpes Simplex Virus Type 1 Encephalitis Based on a Frequency-Selective Nonlinear Blending: Comparison With MRI

Abstract

Frequency-selective nonlinear blending significantly increases contrast and detects brain parenchymal involvement in HSE more sensitively compared with unenhanced CT. The sensitivity of best-contrast CT seems to be equal to that of DWI and almost as good as that of FLAIR.

Autoimmune‐mediated encephalitis and mimics: A neuroimaging review

“…On imaging, both HSV encephalitis and autoimmune limbic encephalitis show T2/FLAIR hyperintensities of the medial temporal lobes with or without associated enhancement, with possible extension into other limbic structures such as the insula, cingulate gyrus, and orbitofrontal cortices (Figure 8A,B,D,E). Restricted diffusion (Figure 8C,F) and hemorrhage in these regions favor HSV as they are typically absent in autoimmune encephalitis 103,104 . Additionally, autoimmune encephalitis frequently involves the basal ganglia, while HSV encephalitis characteristically spares the basal ganglia 5 …”

“…Restricted diffusion (Figure 8C,F) and hemorrhage in these regions favor HSV as they are typically absent in autoimmune encephalitis. 103,104 Additionally, autoimmune encephalitis frequently involves the basal ganglia, while HSV encephalitis characteristically spares the basal ganglia. 5…”

Using Correlative Properties of Neighboring Pixels to Improve Gray-White Differentiation in Pediatric Head CT Images

“…Improved perception of GWD can be expected to be helpful for diagnosing diseases in which it is lost (such as ischemic infarction, encephalitis) as well as for diseases in which gray matter is unduly thickened (such as malformations of cortical development). 1,2,[28][29][30][31] Using the same image-processing algorithm that improved GWD on head CT images with normal findings, previous investigators were able to improve the accuracies of radiologists in diagnosing acute infarction and encephalitis on head CTs. 13,30,32 Further studies are needed to test whether improved gray-white differentiation afforded by CIE on head CT images can translate into similar improved sensitivity for the detection of disease processes such as ischemic infarcts (Fig 5).…”

A review with comments on herpes simplex encephalitis in adults

“…[19] However, it is worth noting that the sensitivity of a new CT post-processing tool based on frequency-selective nonlinear blending (best-contrast CT) seems to be equal to that of DWI and FLAIR, as suggested in a recent study. [20] Unresolved issues in diagnosis PCR-based test in CSF has been established as a gold standard method for the diagnosis of HSE. However, there is evidence of pseudo-negative result influenced by the time of CSF sample collection: the PCR may be negative for HSV-1 during the first 3 days of the illness, [12] however, if the CSF is re-examined after a few days, the PCR may then become positive.…”