Question

High resolution CT (HRCT) of the lung is a specialized CT technique for greater detail of the lung parenchyma. It utilizes:

• A. Special lung filters
• B. Thick collimation
• C. Bone algorithm for image reconstruction
• D. Large field of view

Hint:

HRCT needs thin slices, a small field of view, and a sharp bone-type reconstruction algorithm, not thick slices or a large field.

Answer 1

The Correct Option is C

The question asks what technical trick lets HRCT of the lung show finer detail of the lung tissue than an ordinary chest CT scan.

1. Special lung filters: This is not a defined, standard part of how HRCT is set up, so it does not fit.
2. Thick collimation: Thicker slices average more tissue into each pixel and blur fine detail, which works against the whole point of HRCT, so this is wrong.
3. Bone algorithm for image reconstruction: This sharp, high spatial frequency algorithm boosts edge detail, the same way it is used to bring out fine bone structure, and this same sharpening is exactly what HRCT needs to show the lung's fine architecture, so this fits.
4. Large field of view: A bigger field of view means bigger pixels and less detail per unit area, the opposite of what HRCT is trying to achieve, so this is wrong.

HRCT gets its extra detail from thin slices, a small targeted field of view, and a sharp bone-style reconstruction algorithm. Among the four choices given, the bone algorithm for image reconstruction is the one that correctly describes part of the HRCT technique.

Let's summarize:

• HRCT uses thin collimation, not thick collimation.
• It uses a small field of view, not a large one.
• The sharp, edge-enhancing bone algorithm is what gives HRCT its fine parenchymal detail.

So the correct answer is bone algorithm for image reconstruction.