Airway Dimensions in Asthma and COPD in High Resolution Computed Tomography: Can We See the Difference?

The exact site of airway narrowing in asthma and chronic obstructive pulmonary disease is unknown. High-resolution computed tomography (HRCT) is a sensitive noninvasive imaging technique that can be used to measure airway dimensions. After determining the optimal computed tomographic parameters using a phantom, we measured lobe volume and airway dimensions of isolated canine lung lobes at a transpulmonary pressure of 25 cmH2O. These measurements were repeated after deflation and administration of aerosolized saline and carbachol (256 mg/ml). Lobe volume decreased with all treatments. The maximal lobar volume change was 26% at 6 cmH2O after carbachol. Average airway lumen area decreased with all treatments. After carbachol, at transpulmonary pressures of 25, 15, 10, 8, and 6 cmH2O, lumen area decreased by 7.3 +/- 4.1, 62.0 +/- 4.9, 77.5 +/- 3.0, 31.9 +/- 9.0, and 95.2 +/- 1.0% (SE), respectively. When the airways were divided into four categories on the basis of initial lumen diameter (less than 2, 2–4, 4–6, and greater than 6 mm), the greatest decreases in luminal area after carbachol were seen in intermediate-sized airways (2–4 mm, 56 +/- 4%; 4-6 mm, 59 +/- 3%). HRCT can be used to make accurate measurements of airway dimensions and airway narrowing in excised lungs. HRCT may allow measurement of airway wall thickness and determination of the site of airway narrowing in asthma.

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Volumetric characteristics of idiopathic pulmonary fibrosis lungs: computational analyses of high-resolution computed tomography images of lung lobes

Respiratory Research ◽

10.1186/s12931-019-1189-5 ◽

2019 ◽

Vol 20 (1) ◽

Cited By ~ 1

Author(s):

Bora Sul ◽

Lucia Flors ◽

Joanne Cassani ◽

Michael J. Morris ◽

Jaques Reifman ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Idiopathic Pulmonary Fibrosis ◽

Pulmonary Fibrosis ◽

Lung Volume ◽

High Resolution Computed Tomography ◽

Healthy Group ◽

Volumetric Characteristics ◽

The Difference ◽

Lung Lobes

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease involving progressive degeneration of lung capacity. Current diagnosis of IPF heavily relies on visual evaluation of fibrotic features in high-resolution computed tomography (HRCT) images of the lungs. Although the characteristics of this disease have been studied at the molecular and cellular levels, little is known about the mechanical characteristics of IPF lungs inferred from HRCT images. To this end, we performed a pilot study to investigate the radiographic and volumetric characteristics of lungs in subjects with IPF. Methods We collected HRCT images of healthy (N = 13) and IPF (N = 9) lungs acquired at breath-holds after full inspiration (expanded state) and full expiration (contracted state). We performed statistical analyses on Hounsfield unit (HU) histograms, lobar volumes (V: lobe volume normalized by the lung volume), and lobar flows (Q: the difference in lobe volume divided by the difference in lung volume between the expanded and contracted states). Results Parameters characterizing the HU histograms (i.e., mean, median, skewness, and kurtosis) significantly differed between healthy and IPF subjects, for all lobes in both expanded and contracted states. The distribution of V across lobes differed significantly between the groups in both states. The distribution of Q also differed significantly between the groups: Q values of the lower lobes for the IPF group were 33% (right) and 22% (left) smaller than those for the healthy group, consistent with the observation that radiographic scores were highest in the lower lung section in IPF. Notably, the root-mean-squared difference (RMSD) of Q, a measure of distance from the mean value of the healthy group, clearly distinguished the IPF subjects (RMSD of Q > 1.59) from the healthy group (RMSD of Q < 0.67). Conclusion This study shows that lung volume and flow distribution change heterogeneously across the lung lobes of IPF subjects, with reduced capacity in the lower lobes. These volumetric changes may improve our understanding of the pathophysiology in IPF lungs.

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Quantitative measurement of airway dimensions using ultra-high resolution computed tomography

Respiratory Investigation ◽

10.1016/j.resinv.2018.07.008 ◽

2018 ◽

Vol 56 (6) ◽

pp. 489-496 ◽

Cited By ~ 16

Author(s):

Naoya Tanabe ◽

Tsuyoshi Oguma ◽

Susumu Sato ◽

Takeshi Kubo ◽

Satoshi Kozawa ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Quantitative Measurement ◽

High Resolution Computed Tomography ◽

Airway Dimensions

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Improved visualization of the chorda tympani nerve using ultra‐high-resolution computed tomography

Acta Radiologica Open ◽

10.1177/20584601211061444 ◽

2021 ◽

Vol 10 (11) ◽

pp. 205846012110614

Author(s):

Masahiro Fujiwara ◽

Yoshiyuki Watanabe ◽

Nobuo Kashiwagi ◽

Yumi Ohta ◽

Takashi Sato ◽

...

Keyword(s):

Computed Tomography ◽

High Resolution ◽

Visual Assessment ◽

Middle Ear Surgery ◽

Chorda Tympani ◽

Chorda Tympani Nerve ◽

High Resolution Computed Tomography ◽

High Resolution Ct ◽

The Difference ◽

Temporal Bones

Background Recognition of the anatomical course of the chorda tympani nerve (CTN) is important for preventing iatrogenic injuries during middle-ear surgery. Purpose This study aims to compare visualization of the CTN using two computed tomography (CT) methods: conventional high-resolution CT (C-HRCT) and ultra‐high-resolution CT (U-HRCT). Materials and methods We performed a retrospective visual assessment of 59 CTNs in normal temporal bones of 54 consecutive patients who underwent both C-HRCT and U-HRCT. After dividing CTN into three anatomical segments (posterior canaliculus, tympanic segment, and anterior canaliculus), two neuroradiologists scored the visualizations on a four-point scale. Results On C-HRCT, the visual scores of the posterior canaliculus, tympanic segment, and anterior canaliculus were 3.5 ± 0.7, 1.6 ± 0.6, and 3.1 ± 0.7, respectively. The respective values were significantly higher in all segments on U-HRCT: 3.9 ± 0.2, 2.4 ± 0.6, 3.5 ± 0.6 ( p < 0.01). Although the difference in scores between methods was greatest for the tympanic segment, the visual score on U-HRCT was lower for the tympanic segment than for the anterior and posterior segments ( p < 0.01). Conclusion Ultra‐high-resolution CT provides superior visualization of the CTN, especially the tympanic segment.

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