CourseCourseConceptConceptDocsDocuments

CAIE A-Level Physics A2 24.2.4 Computed Tomography Ct Scanning Produces a 3d Image of an Internal Questions

Practise explaining how CT combines X-ray views into sectional and three-dimensional images, and comparing its diagnostic value and radiation exposure with a single X-ray.

Syllabus
2028–2030
Course
Physics 9702
Level
A2

Exam points

  • explain how CT combines X-ray images from different angles and sections to form a 3D image
  • compare CT with single X-ray imaging, including diagnostic benefit and radiation exposure

CAIE A-Level Physics A2 24.2.4 Computed Tomography Ct Scanning Produces a 3d Image of an Internal Questions question 1

[Maximum number: 7]

Question (a)

(a)

In computed tomography (CT scanning), it is necessary to take a series of many X-ray images. Outline briefly the principles of CT scanning.

[ 4 ]

Question (b)

(b)

A student creates a model for CT scanning.

A section is divided into four voxels, with pixel numbers A, B, C and D , as shown in Fig. 9.1.

Fig. 9.1

Fig. 9.1

The section is viewed from four different directions V1, V2, V3\mathrm{V}_{1}, \mathrm{~V}_{2}, \mathrm{~V}_{3} and V4\mathrm{V}_{4}, as shown in Fig. 9.1.
The detector readings for each direction are noted and then summed. The result is shown in Fig. 9.2.

Fig. 9.2

Fig. 9.2

The background count is 26 .
Determine the pixel numbers A, B, C and D as shown in Fig. 9.1.
A B
D
C

[ 3 ]
All question bank results loaded