common carotid artery/ image j /온목동맥

For your experiment using the common carotid artery in ultrasound imaging, here’s how you can define ROIs and proceed with calculations:

ROI Selection:

1. Artery Wall: This provides a good contrast with the lumen (inside the artery) and surrounding tissue.
2. Esophagus Wall: Often located posterior to the carotid, it can serve as another structure with distinct echogenicity for contrast comparison.
3. Muscle: The surrounding sternocleidomastoid muscle or other adjacent muscles can be used for background or tissue contrast.

Number of ROIs:

For more reliable CNR and SNR values, selecting multiple ROIs from different sections of each structure will help average out any anomalies:

• 3 ROIs from the Artery Wall (inner and outer layers if possible).
• 2–3 ROIs from the Esophagus Wall.
• 3 ROIs from the surrounding Muscle.

Using ImageJ:

Once you have measured the mean intensity and standard deviation from the ROIs in ImageJ:

• SNR: You'll calculate it using the formula:
  • SNR=Mean Signal Intensity (Structure)Standard Deviation (Background Noise)\text{SNR} = \frac{\text{Mean Signal Intensity (Structure)}}{\text{Standard Deviation (Background Noise)}}SNR=Standard Deviation (Background Noise)Mean Signal Intensity (Structure)​.
• CNR: Use the formula:
  • CNR=Mean Intensity (Structure)−Mean Intensity (Background)Standard Deviation of Background\text{CNR} = \frac{\text{Mean Intensity (Structure)} - \text{Mean Intensity (Background)}}{\text{Standard Deviation of Background}}CNR=Standard Deviation of BackgroundMean Intensity (Structure)−Mean Intensity (Background)​.

Calculating CNR and SNR:

Once you have these values (mean intensity and standard deviation) for each ROI, you can either:

• Manually calculate the CNR and SNR using the formulas in a program like Excel.
• Automate the process by creating a simple script or macro to handle the repetitive calculations.

Presenting in a Table:

To present this data in a table format, it should look something like this:

ROIMean IntensityStandard DeviationCNR (Calculated)SNR (Calculated)

Artery Wall	X	Y	Z	W
Esophagus	X	Y	Z	W
Muscle	X	Y	Z	W

You can create this table in Excel, where the CNR and SNR columns are filled by applying the formulas to the respective ROI data.

Statistical Analysis:

To statistically validate your results:

• ANOVA (Analysis of Variance) is a great choice to test if there are statistically significant differences between the groups (e.g., different gel pads affecting the CNR and SNR values).
• Post-hoc tests (like Tukey's test) can help you further analyze which specific pairs of groups are significantly different if the ANOVA results show significance.

For your gel pad experiment, using ANOVA to compare the CNR and SNR values across the different gel pads (carrageenan, regular, gelatin) will provide evidence on whether there's a statistically significant improvement or difference in ultrasound image quality based on the gel type.