Question 1

If the radiation exposure is too ____, the film is overexposed and the processed image appears too ____ and the radiologist cannot make a diagnosis from such an image.

Accepted Answer

If the radiation exposure is too high, the film is overexposed and the processed image appears too dark (also known as "burned out"). This can make it difficult or impossible for the radiologist to make a diagnosis from such an image. Therefore, option B is the correct choice.

Question 2

Other than retrospective analysis, why do vast amount of images generated for the wide range of digital radiology examinations need to be stored?

Accepted Answer

Images need to be stored for medico-legal purposes to ensure that there is a record of the examination that can be referred to in case of legal inquiries or disputes.

Question 3

____ is used to describe the degree of film blackening as a result of radiation exposure, and it can be measured by a densitometer.

Accepted Answer

D

Question 4

The major components of PACS include image acquisition devices, a PACS computer, devices called interfaces, and display workstations, all of which are connected and linked to the HIS and RIS through digital communication networks.

Accepted Answer

This statement is true.

Question 5

As a radiation detector, film-screen cannot show differences in tissue contrast less than ____.

Accepted Answer

Film-screen technology has a limited ability to differentiate between tissues with similar contrast, typically around 10%. This means that differences in tissue contrast that are less than 10% may not be visible on the film. Therefore, choice B (10%) is the correct answer.

Question 6

The film gamma refers to the sensitivity of the film to radiation.

Accepted Answer

Film gamma refers to the contrast of the film, not its sensitivity to radiation. Sensitivity is measured by film speed or ISO.

Question 7

The term ____, as used in this book, refers to projection radiography, whereby computers process data collected from patients using special electronic detectors that have replaced the X-ray film cassette.

Accepted Answer

Digital radiography specifically refers to the use of special electronic detectors and computer processing to generate images, as opposed to traditional X-ray film. While filmless imaging is a related term, it is not specific to the use of electronic detectors and may apply to other types of imaging, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans. Film-screen radiography is the traditional method of X-ray imaging using a combination of X-ray film and a screen to capture and enhance the image, while digital mammography refers specifically to the use of digital technology for breast imaging.

Question 8

The output of computer processing, or the ____, must first be converted into an analog signal before it can be displayed on a monitor for viewing by the observer.

Accepted Answer

A digital image is the output of computer processing that needs to be converted into an analog signal to be displayed on a monitor.

Question 9

A digital fluoroscopy system consists of very few of the imaging components found in a conventional fluoroscopic imaging system.

Accepted Answer

A digital fluoroscopy system includes many of the same imaging components as a conventional fluoroscopic imaging system, such as an X-ray source, image intensifier, and flat panel detector. The main difference is in how the images are captured, processed and displayed.

Question 10

In order to change a(n)____ (optical range and contrast), an additional set of exposure technique factors must be used, thus increasing the dose to the patient from repeated exposures.

Accepted Answer

The answer of In order to change a(n)____ (optical range...

Question 11

The ____ refers to the sensitivity of the film to radiation.

Accepted Answer

Film speed refers to the sensitivity of the film to radiation. It is usually measured in ISO or ASA units. A higher film speed indicates increased sensitivity to radiation, while a lower film speed indicates decreased sensitivity. The other options, B) OD, C) fog density, and D) film density, refer to other properties of film and are not directly related to its sensitivity to radiation.

Question 12

Which major technical component of a digital radiography system refers to the collection of X-rays transmitted through the patient?

Accepted Answer

Data acquisition is the major technical component of a digital radiography system that refers to the collection of X-rays transmitted through the patient. It involves the use of a detector (such as a flat-panel detector) to capture the X-ray photons and convert them into an electrical signal, which is then processed to form a digital image. Image display, post-processing, and image storage are all important components of digital radiography systems, but they are not directly involved in the acquisition of the X-ray data.

Question 13

As a radiation detector, film-screen cannot show differences in tissue contrast less than 30%.

Accepted Answer

The answer of As a radiation detector, film-screen cannot show...

Question 14

For radiography, which of the following is the highest of all the other imaging modalities, and can range from 5 -15 line pairs/mm?

Accepted Answer

Spatial resolution refers to the ability to distinguish small structures and is measured in line pairs per millimeter. Radiography has the highest spatial resolution compared to other imaging modalities, with a range of 5-15 line pairs/mm. Film-screen and contrast resolution also play a role in image quality, but do not necessarily determine the overall spatial resolution. Optical range is not a term commonly used in imaging modalities.

Question 15

Digital radiography imaging modalities include communication radiography (CR), flat-panel digital radiography (DR), digital mammography (DM), and digital fluorescence (DF)and the laser film digitizer.

Accepted Answer

Digital radiography imaging modalities include computed radiography (CR), flat-panel digital radiography (DR), and digital mammography (DM), but not digital fluorescence (DF) or the laser film digitizer.

Question 16

For digital radiography, special electronic (digital)detectors are used that replace the X-ray film cassette used in film-based radiography.

Accepted Answer

Digital radiography uses electronic detectors instead of X-ray film cassettes.

Question 17

Film-screen radiography has been the workhorse of radiology ever since the discovery of X-ray by W.C.Roentgen in 1895.

Accepted Answer

Film-screen radiography has been widely used in radiology since its inception in 1895, making it the workhorse of radiology.

Question 18

The purpose of image compression is to increase storage space and decrease the image transmission time.

Accepted Answer

The purpose of image compression is to decrease storage space and reduce image transmission time by reducing the file size.

Question 19

A high-end computer is the heart of the PACS system.

Accepted Answer

A high-end computer is typically required to handle the large volumes of medical image data and perform advanced processing tasks, making it a critical component of a PACS system.

Question 20

The digital detector output signal is linear with the input radiation exposure.

Accepted Answer

Digital detectors are designed to have a linear response to radiation exposure, meaning that the output signal is directly proportional to the radiation received. This allows for accurate measurement and quantification of radiation doses.

Quiz 1: Digital Radiography: An Overview

If the radiation exposure is too , the film is overexposed and the processed image appears too and the radiologist cannot make a diagnosis from such an image.