Forum:Seminar papers/Biophysics/2. LF/2017-2018/Group 4B (Isabel): MCQ - Ionizing Radiations, Biosignals

A. Ionizing Radiations

1. Which statement is true?

a) The attenuation coefficient measured in CT imaging is a measure of how much tissue in given voxel absorbs ultrasound waves b) Medical imaging is a visual representation of a physical variable c) Medical imaging is a visual representation of a biological variable d) the most common MRI machine uses a magnetic field of 2,5 mT

2. The physical half life of Tc-99m is:

a) 6 hours b) 72 hours c) 3 days d) 50 years

3. The principle of H-NMR is based on which of the following property of protons?

a) up and down quarks b) proton spin c) proton charge d) atomic mass of proton

4. Which is the least dangerous medical imaging technique?

a) NMR b) Ultrasound c) X ray imaging d) CT scan

5. Which statement below is correct:

a) Ionizing radiation photons carry less energy than non-ionizing radiation b) x-ray radiation does not belong to ionizing radiation c) Ionizing radiation is not electromagnetic radiation d) Gamma rays are ionizing radiation

B. Biosignals

1. Electric biosignals are:

a) produced by the heart b) signals created during muscle contractions c) produced in the brain d) all of the above

2. The biomedical signal variable may be a function of:

a) continuous signals and pulses. b) active and passive signals. c) time and measurement of voltage in electrodes. d) time and measurement of position in the patient.

3. Polarisable electrodes are NOT suitable for accurate measurements because:

a) they produce constant contact potential. b) they produce variable contact bias. c) they produce electrolytes. d) they produce no variable contact bias.

4. What are the frequencies and amplitudes of alpha and beta waves, respectively?

a) Alpha waves: 8 - 13 Hz, 50 μV max; Beta waves: 15 - 20 Hz, 5 - 10 μV. b) Alpha waves: 15 - 20 Hz, 5 - 10 μV; Beta waves: 8 - 13 Hz, 50 μV max. c) Alpha waves: 8 - 13 Hz, 50 μV max; Beta waves: 1 - 4 Hz, 100 μV. d) Alpha waves: 1 - 4 Hz, 100 μV, Beta waves: 15 - 20 Hz, 5 - 10 μV.

5. Artefacts are features of signals not arising from the target tissue, but either from outside the patient or:

a) from incorrect use of the measuring instrument. b) from non-targeted tissues. c) from deficiencies in the measuring instrument. d) all of the above.