Option C: Imaging (Additional higher level option topics)

Explain the cause of the radio-frequency emissions from a patient’s body during nuclear magnetic resonance (NMR) imaging.

Explain the cause of the radio-frequency emissions from a patient’s body during nuclear magnetic resonance (NMR) imaging.

Explain the cause of the radio-frequency emissions from a patient’s body during nuclear magnetic resonance (NMR) imaging.

Explain, with appropriate calculations, why a gel is used between the transducer and the skin.

Explain, with appropriate calculations, why a gel is used between the transducer and the skin.

Explain, with appropriate calculations, why a gel is used between the transducer and the skin.

Describe one advantage and one disadvantage of using high frequencies ultrasound over low frequencies ultra sound for medical imaging.

Describe one advantage and one disadvantage of using high frequencies ultrasound over low frequencies ultra sound for medical imaging.

Describe one advantage and one disadvantage of using high frequencies ultrasound over low frequencies ultra sound for medical imaging.

Outline the formation of a B scan in medical ultrasound imaging.

Outline the formation of a B scan in medical ultrasound imaging.

Outline the formation of a B scan in medical ultrasound imaging.

A monochromatic X-ray beam of energy 20 keV and intensity I₀ penetrates 5.00 cm of fat and then 4.00 cm of muscle.

Calculate, in terms of I₀, the final beam intensity that emerges from the muscle.

A monochromatic X-ray beam of energy 20 keV and intensity I₀ penetrates 5.00 cm of fat and then 4.00 cm of muscle.

Calculate, in terms of I₀, the final beam intensity that emerges from the muscle.

A monochromatic X-ray beam of energy 20 keV and intensity I₀ penetrates 5.00 cm of fat and then 4.00 cm of muscle.

Calculate, in terms of I₀, the final beam intensity that emerges from the muscle.

Describe how the measurement in (b) provides diagnostic information for the doctor.

Describe how the measurement in (b) provides diagnostic information for the doctor.

Describe how the measurement in (b) provides diagnostic information for the doctor.

Determine, in terms of I₀, the intensity of ultrasound that is reflected at the muscle–bone boundary.

Determine, in terms of I₀, the intensity of ultrasound that is reflected at the muscle–bone boundary.

Determine, in terms of I₀, the intensity of ultrasound that is reflected at the muscle–bone boundary.

Ultrasound of intensity 50 mW m^-2 is incident on a muscle. The reflected intensity is 10 mW m^-2. Calculate the relative intensity level between the reflected and transmitted signals.

Ultrasound of intensity 50 mW m^-2 is incident on a muscle. The reflected intensity is 10 mW m^-2. Calculate the relative intensity level between the reflected and transmitted signals.

Ultrasound of intensity 50 mW m^-2 is incident on a muscle. The reflected intensity is 10 mW m^-2. Calculate the relative intensity level between the reflected and transmitted signals.

The acoustic impedance of soft tissue is 1.65 × 106 kg m^-2 s^-1. Show that the speed of sound in the soft tissue is approximately 1500 m s^–1.

The acoustic impedance of soft tissue is 1.65 × 106 kg m^-2 s^-1. Show that the speed of sound in the soft tissue is approximately 1500 m s^–1.

The acoustic impedance of soft tissue is 1.65 × 106 kg m^-2 s^-1. Show that the speed of sound in the soft tissue is approximately 1500 m s^–1.

A physician has a range of frequencies available for ultrasound. Comment on the use of higher frequency sound waves in an ultrasound imaging study.

A physician has a range of frequencies available for ultrasound. Comment on the use of higher frequency sound waves in an ultrasound imaging study.

A physician has a range of frequencies available for ultrasound. Comment on the use of higher frequency sound waves in an ultrasound imaging study.

Suggest the advantage in medical diagnosis of using ultrasound of frequency 1 MHz rather than 0.1 MHz.

Suggest the advantage in medical diagnosis of using ultrasound of frequency 1 MHz rather than 0.1 MHz.

Suggest the advantage in medical diagnosis of using ultrasound of frequency 1 MHz rather than 0.1 MHz.

The fluid in the bowel has a similar linear attenuation coefficient as the bowel surface. Gases have much lower linear attenuation coefficients than fluids. Explain why doctors will fill the bowel with air before taking an X-ray image.

The fluid in the bowel has a similar linear attenuation coefficient as the bowel surface. Gases have much lower linear attenuation coefficients than fluids. Explain why doctors will fill the bowel with air before taking an X-ray image.

The fluid in the bowel has a similar linear attenuation coefficient as the bowel surface. Gases have much lower linear attenuation coefficients than fluids. Explain why doctors will fill the bowel with air before taking an X-ray image.

A parallel beam of X-rays travels through 7.8 cm of tissue to reach the bowel surface. Calculate the fraction of the original intensity of the X-rays that reach the bowel surface. The linear attenuation coefficient for tissue is 0.24 cm^–1.

A parallel beam of X-rays travels through 7.8 cm of tissue to reach the bowel surface. Calculate the fraction of the original intensity of the X-rays that reach the bowel surface. The linear attenuation coefficient for tissue is 0.24 cm^–1.

A parallel beam of X-rays travels through 7.8 cm of tissue to reach the bowel surface. Calculate the fraction of the original intensity of the X-rays that reach the bowel surface. The linear attenuation coefficient for tissue is 0.24 cm^–1.

State and explain, with reference to you answer in (a)(i), what needs to be done to produce a clear image of the leg artery using X-rays.

State and explain, with reference to you answer in (a)(i), what needs to be done to produce a clear image of the leg artery using X-rays.

State and explain, with reference to you answer in (a)(i), what needs to be done to produce a clear image of the leg artery using X-rays.

A technician operates an X-ray machine that takes 100 images each day. Estimate the width of the lead screen that is required so that the total exposure of the technician in 250 working days is equal to the exposure that the technician would receive from one X-ray exposure without the lead screen.

A technician operates an X-ray machine that takes 100 images each day. Estimate the width of the lead screen that is required so that the total exposure of the technician in 250 working days is equal to the exposure that the technician would receive from one X-ray exposure without the lead screen.

A technician operates an X-ray machine that takes 100 images each day. Estimate the width of the lead screen that is required so that the total exposure of the technician in 250 working days is equal to the exposure that the technician would receive from one X-ray exposure without the lead screen.

Outline how ultrasound is generated for medical imaging.

Outline how ultrasound is generated for medical imaging.

Outline how ultrasound is generated for medical imaging.

Suggest one reason why doctors use ultrasound rather than X-rays to monitor the development of a fetus. 

Suggest one reason why doctors use ultrasound rather than X-rays to monitor the development of a fetus. 

Suggest one reason why doctors use ultrasound rather than X-rays to monitor the development of a fetus. 

Calculate the density of skin.

Calculate the density of skin.

Calculate the density of skin.

State what is meant by half-value thickness in X-ray imaging.

State what is meant by half-value thickness in X-ray imaging.

State what is meant by half-value thickness in X-ray imaging.

Compare the use of high and low energy X-rays for medical imaging.

Compare the use of high and low energy X-rays for medical imaging.

Compare the use of high and low energy X-rays for medical imaging.

In the ultrasound scan the frequency is chosen so that the distance between the transducer and the organ is at least 200 ultrasound wavelengths. Estimate, based on your response to (b)(ii), the minimum ultrasound frequency that is used.

In the ultrasound scan the frequency is chosen so that the distance between the transducer and the organ is at least 200 ultrasound wavelengths. Estimate, based on your response to (b)(ii), the minimum ultrasound frequency that is used.

In the ultrasound scan the frequency is chosen so that the distance between the transducer and the organ is at least 200 ultrasound wavelengths. Estimate, based on your response to (b)(ii), the minimum ultrasound frequency that is used.

Show that the ratio $\frac{I_{\mathrm{b}}}{I_{\mathrm{t}}}$ is close to 1.

Show that the ratio $\frac{I_{\mathrm{b}}}{I_{\mathrm{t}}}$ is close to 1.

Show that the ratio $\frac{I_{\mathrm{b}}}{I_{\mathrm{t}}}$ is close to 1.

In nuclear magnetic resonance (NMR) protons inside a patient are made to emit a radio frequency electromagnetic radiation. Outline the mechanism by which this radiation is emitted by the protons.

In nuclear magnetic resonance (NMR) protons inside a patient are made to emit a radio frequency electromagnetic radiation. Outline the mechanism by which this radiation is emitted by the protons.

In nuclear magnetic resonance (NMR) protons inside a patient are made to emit a radio frequency electromagnetic radiation. Outline the mechanism by which this radiation is emitted by the protons.

Outline how a gradient field allows NMR to be used in medical resonance imaging.

Outline how a gradient field allows NMR to be used in medical resonance imaging.

Outline how a gradient field allows NMR to be used in medical resonance imaging.