For our first projection, we took an initial exposure using 60 kVp and 1 mAs, resulting in a DI of +0.8. This overexposure indicated the need to reduce mAs. Using the 30% mAs rule, the mAs was incrementally decreased to 0.63, producing a DI of +0.3. Since the DI value was in an acceptable range, we felt our technique was justified. The final technique involved in producing an optimal image with a fixed kVp was 60 kVp @ .63 mAs.

In our second projection, our first exposure taken at 60 kVp and 1.6 mAs resulted in a DI of +0.7 (overexposed). We decided to decrease mAs and discovered that 1.4 mAs would yield a DI of +0.1. The final technique involved in producing an optimal image with a fixed kVp was 60 kVp @ 1.4 mAs.

During our third projection, an initial test exposure of 70 kVp and 5.0 mAs resulted in a DI of +1.2. We decided to raise kVp to 75 to achieve proper part penetration. Since we increased kVp, this means we need to decrease mAs. Decreasing the mAs to 2.8 brought the DI to +0.1. The final technique involved in producing an optimal image with a fixed kVp was 75 kVp @ 2.8 mAs.

For our fourth projection, we decided 75 kVp would be enough to penetrate that part since the knee and shoulder shared similar thickness measurements. We started with 75 kVp and 4.0 mAs, the DI was -0.6. Increasing mAs by at least 30% to 5.6 produced a DI of -0.2 with improved brightness and contrast. The final technique involved in producing an optimal image with a fixed kVp was 75 kVp @ 5.6 mAs.

For our fifth projection, an initial exposure taken at 75 kVp with a mAs of 6.5 yielded a DI value of -0.8. We increased mAs to 8.0 which produced a DI of +0.1. The final technique involved in producing an optimal image with a fixed kVp was 75 kVp @ 8 mAs.

In our sixth projection, the first exposure was taken at 75 kVp and 10 mAs. This generated a DI was -2.7. By increasing the mAs to 14.0, we achieved an optimal exposure that resulted in DI of 0.0. The final technique involved in producing an optimal image with a fixed kVp was 75 kVp @ 14 mAs.

Our seventh projection presented more difficulties for us since we hadn’t positioned ribs before. Initial settings on the console of 75 kVp and 8 mAs produced a DI of -1.8 (underexposed). Increasing mAs to 11 resulted in a DI of -0.5, which was in the acceptable range. The final technique involved in producing an optimal image with a fixed kVp was 75 kVp @ 11 mAs.

For our eighth projection, an initial exposure was taken at 75 kVp at 12.5 mAs, which resulted in a DI value of  -9.9, indicating a severe underexposure. We tested several values for mAs until we landed at 40 mAs, which finally generated an acceptable DI value of -0.1. This projection required the highest mAs increase out of all the projections. The final technique involved in producing an optimal image with a fixed kVp was 75 kVp @ 40 mAs.

In our ninth projection, we took our initial exposure at 110 kVp and 5.0 mAs, which generated an image with a DI value of 0.4. However, we decided to retake our exposure at a lower kVp value of 80 since that value would still provide sufficient penetration of the part without excessive patient dose. At 80 kVp, a mAs value of 18 generated an optimal image with a 0.0 DI value. The final technique involved in producing an optimal image with a fixed kVp was 80 kVp @ 18 mAs.

Our final projection required more maneuvering when it came to phantom positioning, but with critical thinking skills, we were able to achieve an optimal image with a kVp value of 110 and a mAs value of 0.8. This generated a DI value of -0.3. These technical factors helped us balance spatial resolution and contrast and provided adequate penetration of the phantom’s lung field. The final technique involved in producing an optimal image with a fixed kVp was 110 kVp @ 0.8 mAs.