A pelvis radiograph is taken with 80 kVp, 30 mAs, and at a distance of 44 inches. If the distance is reduced to 36 inches while maintaining 80 kVp, what will the new intensity be? What mAs should be used to keep the radiographic exposure consistent?

To solve this problem, we need to use the **inverse square law** and the **mAs distance compensation formula**.

### Step 1: Determine the New Intensity
The inverse square law states that the intensity of radiation is inversely proportional to the square of the distance from the source. Mathematically, this is expressed as:

\[
\frac{I_1}{I_2} = \left(\frac{D_2}{D_1}\right)^2
\]

Where:
- \(I_1\) is the initial intensity
- \(I_2\) is the new intensity
- \(D_1\) is the initial distance
- \(D_2\) is the new distance

Given:
- \(D_1 = 44\) inches
- \(D_2 = 36\) inches

Substituting the values:

\[
\frac{I_1}{I_2} = \left(\frac{36}{44}\right)^2
\]

\[
\frac{I_1}{I_2} = \left(\frac{36}{44}\right)^2 \approx \left(0.818\right)^2 \approx 0.669
\]

\[
I_2 = \frac{I_1}{0.669} \approx 1.495 \times I_1
\]

So, the new intensity \(I_2\) will be approximately **1.495 times** the initial intensity \(I_1\).

### Step 2: Calculate the New mAs to Maintain Consistent Exposure
To maintain consistent radiographic exposure, the mAs should be adjusted according to the change in distance using the following formula:

\[
\text{New } mAs = \text{Old } mAs \times \left(\frac{D_2}{D_1}\right)^2
\]

Substituting the given values:

\[
\text{New } mAs = 30 \times \left(\frac{36}{44}\right)^2
\]

\[
\text{New } mAs = 30 \times 0.669 \approx 20.07 \text{ mAs}
\]

### Final Answers:
1. **New Intensity:** The new intensity will be approximately **1.495 times** the initial intensity.
2. **New mAs:** To keep the radiographic exposure consistent, the new mAs should be approximately **20.07 mAs**.

Would you like more details or have any questions?

### Related Questions:
1. How does the inverse square law apply to other forms of energy besides X-rays?
2. What other factors besides distance can affect radiographic exposure?
3. How does changing the kVp affect the intensity of an X-ray beam?
4. What is the relationship between mAs and patient dose?
5. How do grid ratios affect radiographic exposure and patient dose?

### Tip:
Always double-check your distance and exposure settings to ensure optimal image quality while minimizing patient exposure.

Understand how to calculate the new intensity and adjust mAs for a pelvis radiograph when the distance is reduced from 44 inches to 36 inches. This problem covers key radiographic physics concepts like the inverse square law and exposure calculation. Suitable for college-level radiologic technology students.

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