Which tolerance is specified for CT number accuracy in water regions?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $25.99Unlock all

Master the Task Group 142 Tolerances Test with comprehensive quizzes and insights, including question explanations and essential tips. Prepare for success!

Multiple Choice

Which tolerance is specified for CT number accuracy in water regions?

Explanation:
In CT number accuracy testing, water is the reference point because its CT number is defined as 0 HU. The goal is to ensure the measured CT number within a water region stays very close to zero despite normal system variations. A tolerance of ±5 HU accommodates typical day-to-day fluctuations from calibration drift, reconstruction algorithms, and noise, while still keeping the baseline reliable for distinguishing tissues. Choosing ±2 or ±3 HU would be too tight for routine operation, and ±7 HU would be more permissive than standard practice. The widely accepted tolerance that balances accuracy and practicality is ±5 HU.

In CT number accuracy testing, water is the reference point because its CT number is defined as 0 HU. The goal is to ensure the measured CT number within a water region stays very close to zero despite normal system variations. A tolerance of ±5 HU accommodates typical day-to-day fluctuations from calibration drift, reconstruction algorithms, and noise, while still keeping the baseline reliable for distinguishing tissues.

Choosing ±2 or ±3 HU would be too tight for routine operation, and ±7 HU would be more permissive than standard practice. The widely accepted tolerance that balances accuracy and practicality is ±5 HU.

More Multiple Choice Questions
Subscribe

Get the latest from Passetra

You can unsubscribe at any time. Read our privacy policy