A radiograph of the forearm is acquired using 2.5 milliamperage (mA) at 60 kilovoltage peak (kVp). What new kVp is required to double the exposure?

A radiograph of the forearm is acquired using 2.5 milliamperage (mA) at 60 kilovoltage peak (kVp). What new kVp is required to double the exposure?

• A. 65 kVp
• B. 68 kVp
• C. 69 kVp
• D. 72 kVp

Answer: (C)

To understand the required change in kilovoltage peak (kVp) necessary to double the exposure in radiography, it's essential to recognize the relationship between kVp and exposure. Doubling the exposure typically involves increasing the kVp by a specific percentage. In general, a rule of thumb in radiography is that a 15% increase in kVp will double the exposure at the image receptor. Starting with an initial kVp of 60, calculating a 15% increase gives a value of 9 (15% of 60). Adding this to the original kVp results in approximately 69 kVp (60 + 9 = 69). This calculation aligns with the principles of radiographic imaging and helps ensure that the proper techniques are used to achieve the desired exposure levels while maintaining image quality. Thus, increasing the kVp to 69 will effectively double the exposure as required by the question.

To understand the required change in kilovoltage peak (kVp) necessary to double the exposure in radiography, it's essential to recognize the relationship between kVp and exposure. Doubling the exposure typically involves increasing the kVp by a specific percentage.

In general, a rule of thumb in radiography is that a 15% increase in kVp will double the exposure at the image receptor. Starting with an initial kVp of 60, calculating a 15% increase gives a value of 9 (15% of 60). Adding this to the original kVp results in approximately 69 kVp (60 + 9 = 69).

This calculation aligns with the principles of radiographic imaging and helps ensure that the proper techniques are used to achieve the desired exposure levels while maintaining image quality. Thus, increasing the kVp to 69 will effectively double the exposure as required by the question.