Journal: Scientific Reports

Article Title: Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound

doi: 10.1038/s41598-022-17319-4

Figure Lengend Snippet: CT contrast of the skull compared to various MR contrasts (skull A). Cortical and trabecular bone contrast is clearly depicted by CT and may be preserved by two of the three MR post-processing methods. The units for MRsimCT, –log(short TE), and short TE–long TE are not the same, thus different windowing and leveling were used. Scale bars and skull density ratios (SDRs) are shown at the bottom of each image. MRsimCT was the preferred choice based on bone contrast, minimal SDR change compared to CT, minimal background signal bias, and generalizable post-processing. Therefore, it was used for the remainder of this study.

Article Snippet: When targeting the geometric focus, the InSightec MR binary image mask, InSightec MRsimCT, and InSightec CT achieved comparable phase correction performance with respect to normalized target intensity, normalized peak intensity, positioning error, and focal spot volume (Fig. , Table ).

Techniques:

Journal: Scientific Reports

Article Title: Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound

doi: 10.1038/s41598-022-17319-4

Figure Lengend Snippet: Relationship between CT and MRsimCT values. MRsimCT values prior to HU bone scaling in (2) span a range from 0 to 1 and can be used as an estimate for bone fraction. For the CT parameters used in this study, pure bone was calculated to have a value of 2000 HU . The black line depicts the nominal relationship between CT and MRsimCT values. Because only three ex vivo skulls were used in this study, using a linear regression to predict CT HU from MRsimCT values may overfit to the data. Therefore, the nominal linear relationship was used to predict CT HU instead.

Article Snippet: When targeting the geometric focus, the InSightec MR binary image mask, InSightec MRsimCT, and InSightec CT achieved comparable phase correction performance with respect to normalized target intensity, normalized peak intensity, positioning error, and focal spot volume (Fig. , Table ).

Techniques: Ex Vivo

Journal: Scientific Reports

Article Title: Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound

doi: 10.1038/s41598-022-17319-4

Figure Lengend Snippet: Summary of results for the phase corrected focal spots (target at the geometric focus).

Article Snippet: When targeting the geometric focus, the InSightec MR binary image mask, InSightec MRsimCT, and InSightec CT achieved comparable phase correction performance with respect to normalized target intensity, normalized peak intensity, positioning error, and focal spot volume (Fig. , Table ).

Techniques:

Journal: Scientific Reports

Article Title: Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound

doi: 10.1038/s41598-022-17319-4

Figure Lengend Snippet: CT contrast of the skull compared to various MR contrasts (skull A). Cortical and trabecular bone contrast is clearly depicted by CT and may be preserved by two of the three MR post-processing methods. The units for MRsimCT, –log(short TE), and short TE–long TE are not the same, thus different windowing and leveling were used. Scale bars and skull density ratios (SDRs) are shown at the bottom of each image. MRsimCT was the preferred choice based on bone contrast, minimal SDR change compared to CT, minimal background signal bias, and generalizable post-processing. Therefore, it was used for the remainder of this study.

Article Snippet: 3D hydrophone raster scans were acquired for five sets of phase corrections: no correction, InSightec MR binary image mask, InSightec MRsimCT, InSightec CT, and hydrophone.

Techniques:

Journal: Scientific Reports

Article Title: Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound

doi: 10.1038/s41598-022-17319-4

Figure Lengend Snippet: Relationship between CT and MRsimCT values. MRsimCT values prior to HU bone scaling in (2) span a range from 0 to 1 and can be used as an estimate for bone fraction. For the CT parameters used in this study, pure bone was calculated to have a value of 2000 HU . The black line depicts the nominal relationship between CT and MRsimCT values. Because only three ex vivo skulls were used in this study, using a linear regression to predict CT HU from MRsimCT values may overfit to the data. Therefore, the nominal linear relationship was used to predict CT HU instead.

Article Snippet: 3D hydrophone raster scans were acquired for five sets of phase corrections: no correction, InSightec MR binary image mask, InSightec MRsimCT, InSightec CT, and hydrophone.

Techniques: Ex Vivo

Journal: Scientific Reports

Article Title: Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound

doi: 10.1038/s41598-022-17319-4

Figure Lengend Snippet: Summary of results for the phase corrected focal spots (target at the geometric focus).

Article Snippet: 3D hydrophone raster scans were acquired for five sets of phase corrections: no correction, InSightec MR binary image mask, InSightec MRsimCT, InSightec CT, and hydrophone.

Techniques: