SPI Review Part 1

What is the process of improving the visibility of edges in an image called?

• Coded Excitation

• Edge Enhancement

• Speckle Reduction

• Dynamic Range Adjustment

Answer explanation

The process of improving the visibility of edges in an image is known as Edge Enhancement. This technique increases the contrast at the edges, making them more distinct and easier to identify.

Which principle is used to describe the relationship between flow and velocity in hemodynamics?

• Doppler's Principle

• Bernoulli's Principle

• Pascal's Principle

• Archimedes' Principle

Answer explanation

Bernoulli's Principle describes how an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or potential energy. This principle is fundamental in understanding the relationship between flow and velocity in hemodynamics.

What type of Doppler is used to measure high velocity blood flow?

• Continuous Wave Doppler

• Pulsed Wave Doppler

• Color Flow Doppler

• Spectral Doppler

Answer explanation

Continuous Wave Doppler is used to measure high velocity blood flow because it can assess high-speed movements without aliasing, unlike Pulsed Wave Doppler, which is limited by its sampling rate.

Which artifact occurs due to multiple reflections between two strong reflectors?

• Reverberations

• Shadowing

• Enhancement

• Aliasing

Answer explanation

Reverberations occur when sound waves reflect multiple times between two strong reflectors, creating a series of echoes. This phenomenon is distinct from shadowing, enhancement, and aliasing, making it the correct choice.

What is a non-thermal mechanism mentioned in the bioeffects section?

• Cavitation

• Thermal Mechanism

• Electrical Hazards

• Performance Measures

Answer explanation

Cavitation is a non-thermal mechanism that refers to the formation and collapse of bubbles in a liquid, which can cause significant biological effects. The other options either relate to thermal effects or are not mechanisms.

What is the importance of including units with numerical values?

• Units make numbers more ambiguous.

• Units are not necessary for understanding.

• Units provide clarity and context.

• Units are only needed in scientific contexts.

Answer explanation

Units provide clarity and context by specifying what a numerical value represents, such as meters for distance or seconds for time. This prevents ambiguity and enhances understanding, making them essential in all contexts.

Which of the following is an example of a unit for measuring length?

• cm

• cm²

• cm³

• seconds

Answer explanation

The correct choice is 'cm' as it is a unit of length. 'cm²' and 'cm³' are units of area and volume, respectively, while 'seconds' measure time, not length.

What is the unit for measuring area?

• cm

• cm²

• cm³

• ft

Answer explanation

The unit for measuring area is cm², which represents square centimeters. This is used to quantify two-dimensional space. The other options, cm and ft, measure length, while cm³ measures volume.

How can volume be measured according to the text?

• By using a ruler

• By measuring the displaced water

• By counting the number of objects

• By using a stopwatch

Answer explanation

Volume can be measured by measuring the displaced water, which is a common method for irregularly shaped objects. This technique accurately determines the volume based on the amount of water displaced when the object is submerged.

Which of the following is NOT considered a unit?

• Percent

• cm

• ft

• cm²

Answer explanation

Percent is a ratio that expresses a number as a fraction of 100, but it does not represent a physical measurement like cm (centimeters), ft (feet), or cm² (square centimeters), which are all units of length or area.