Dataset Information

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

ABSTRACT:

Purpose

The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners.

Materials and methods

This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner.

Results

The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures.

Conclusion

Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners.

SUBMITTER: Kakinuma R

PROVIDER: S-EPMC4564227 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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Publications

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

Kakinuma Ryutaro R Moriyama Noriyuki N Muramatsu Yukio Y Gomi Shiho S Suzuki Masahiro M Nagasawa Hirobumi H Kusumoto Masahiko M Aso Tomohiko T Muramatsu Yoshihisa Y Tsuchida Takaaki T Tsuta Koji K Maeshima Akiko Miyagi AM Tochigi Naobumi N Watanabe Shun-Ichi S Sugihara Naoki N Tsukagoshi Shinsuke S Saito Yasuo Y Kazama Masahiro M Ashizawa Kazuto K Awai Kazuo K Honda Osamu O Ishikawa Hiroyuki H Koizumi Naoya N Komoto Daisuke D Moriya Hiroshi H Oda Seitaro S Oshiro Yasuji Y Yanagawa Masahiro M Tomiyama Noriyuki N Asamura Hisao H

PloS one 20150909 9

<h4>Purpose</h4>The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners.<h4>Materials and methods</h4>This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. ...[more]

PMID: 26352144

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Project description:ObjectivesThis study was conducted in order to compare the effect of field of view (FOV) size on image quality between ultra-high-resolution CT (U-HRCT) and conventional high-resolution CT (HRCT).MethodsEleven cadaveric lungs were scanned with U-HRCT and conventional HRCT and reconstructed with five FOVs (40, 80, 160, 240, and 320 mm). Three radiologists evaluated and scored the images. Three image evaluations were performed, comparing the image quality with the five FOVs with respect to the 160-mm FOV. The first evaluation was performed on conventional HRCT images, and the second evaluation on U-HRCT images. Images were scored on normal structure, abnormal findings, and overall image quality. The third evaluation was a comparison of the images obtained with conventional HRCT and U-HRCT, with scoring performed on overall image quality. Quantitative evaluation of noise was performed by setting ROIs.ResultsIn conventional HRCT, image quality was improved when the FOV was reduced to 160 mm. In U-HRCT, image quality, except for noise, improved when the FOV was reduced to 80 mm. In the third evaluation, overall image quality was improved in U-HRCT over conventional HRCT at all FOVs. Noise of U-HRCT increased with respect to conventional HRCT when the FOV was reduced from 160 to 40 mm. However, at 240- and 320-mm FOVs, the noise of U-HRCT and conventional HRCT showed no differences.ConclusionsIn conventional HRCT, image quality did not improve when the FOV was reduced below 160 mm. However, in U-HRCT, image quality improved even when the FOV was reduced to 80 mm.Key points• Reducing the size of the field of view to 160 mm improves diagnostic imaging quality in high-resolution CT. • In ultra-high-resolution CT, improvements in image quality can be obtained by reducing the size of the field of view to 80 mm. • Ultra-high-resolution CT produces images of higher quality compared with conventional HRCT irrespective of the size of the field of view.

Dataset Information

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

Purpose

Materials and methods

Results

Conclusion

Publications

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

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