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- Diaz, Sandra, et al.
(författare)
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Hyperpolarized (3)He apparent diffusion coefficient MRI of the lung: Reproducibility and volume dependency in healthy volunteers and patients with emphysema.
- 2008
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Ingår i: Journal of Magnetic Resonance Imaging. - : Wiley. - 1522-2586 .- 1053-1807. ; 27, s. 763-770
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To measure the apparent diffusion coefficient (ADC) of hyperpolarized (HP) (3)He gas using diffusion weighted MRI in healthy volunteers and patients with emphysema and examine the reproducibility and volume dependency. MATERIALS AND METHODS: A total of eight healthy volunteers and 16 patients with emphysema were examined after inhalation of HP (3)He gas mixed with nitrogen (N(2)) during breathhold starting from functional residual capacity (FRC) in supine position. Coronal diffusion-sensitized MR images were acquired. Each subject was imaged on three separate days over a seven-day period and received two different volumes (6% and 15% of total lung capacity [TLC]) of HP (3)He each day. ADC maps and histograms were calculated. The mean and standard deviation (SD) of the ADC at different days and volumes were compared. RESULTS: The reproducibility of the mean ADC and SD over several days was good in both healthy volunteers and patients (SD range of 0.003-0.013 cm(2)/second and 0.001-0.009 cm(2)/second at 6% and 15% of TLC for healthy volunteers, and a SD range of 0.001-0.041 cm(2)/second and 0.001-0.011 cm(2)/second, respectively, for patients). A minor but significant increase in mean ADC with increased inhaled gas volume was observed in both groups. CONCLUSION: Mean ADC and SD of HP (3)He MRI is reproducible and discriminates well between healthy controls and patients with emphysema at the higher gas volume. This method is robust and may be useful to gain new insights into the pathophysiology and course of emphysema. J. Magn. Reson. Imaging 2008. (c) 2008 Wiley-Liss, Inc.
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| 2. |
- Diaz, Sandra, et al.
(författare)
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Validity of apparent diffusion coefficient hyperpolarized He-3-MRI using MSCT and pulmonary function tests as references
- 2009
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Ingår i: European Journal of Radiology. - : Elsevier BV. - 1872-7727 .- 0720-048X. ; 71:2, s. 257-263
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium (He-3)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). Materials and methods: Twenty-seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with Hp He-3-MRI and MSCT. Mean age was 55 (+/- 12) years, 18 female and 9 male. Mean ADC from He-3-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. Results: Mean ADC and standard deviation values were 0.392 +/- 0.119 cm(2)/s for the established emphysema group and 0.216 +/- 0.046 for the pre-clinical emphysema group. MSCT values for the established emphysema group and pre-clinical emphysema group were: EI (%) 11 +/- 12 and 0.4 +/- 0.6, respectively; 15th percentile (Hounsfield Units (HU)), -956 +/- 25 and -933 +/- 13, respectively and MLD (HU) -877 +/- 20 and -863 +/- 15, respectively. Correlations between mean ADC and El and 15th percentile were both r=0.90 and for MLD r=0.59. There was higher correlation between mean ADC and %predicted DLCO (r=0.90) than between El and %predicted DLCO (r=0.76). Conclusion: Hp He-3-MRI correlates well with density measurements from MSCT and agrees better than MSCT with %predicted DLCO which is the PFT most related to emphysema. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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| 4. |
- Aaltonen, H. Laura, et al.
(författare)
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Airspace dimension assessment with nanoparticles as a proposed biomarker for emphysema
- 2021
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Ingår i: Thorax. - : BMJ. - 0040-6376 .- 1468-3296. ; 76:10, s. 1040-1043
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Tidskriftsartikel (refereegranskat)abstract
- Airspace dimension assessment with nanoparticles (AiDA) is a novel method to measure distal airspace radius non-invasively. In this study, AiDA radii were measured in 618 individuals from the population-based Swedish CArdiopulmonary BioImaging Study, SCAPIS. Subjects with emphysema detected by computed tomography were compared to non-emphysematous subjects. The 47 individuals with mainly mild-to-moderate visually detected emphysema had significantly larger AiDA radii, compared with non-emphysematous subjects (326±48 μm vs 291±36 μm); OR for emphysema per 10 μm: 1.22 (1.13-1.30, p<0.0001). Emphysema according to CT densitometry was similarly associated with larger radii compared with non-emphysematous CT examinations (316±41 μm vs 291 μm±26 μm); OR per 10 μm: 1.16 (1.08-1.24, p<0.0001). The results are in line with comparable studies. The results show that AiDA is a potential biomarker for emphysema in individuals in the general population.
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| 7. |
- Alamidi, Daniel, et al.
(författare)
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T1 Relaxation Time in Lungs of Asymptomatic Smokers.
- 2016
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Interest in using T1 as a potential MRI biomarker of chronic obstructive pulmonary disease (COPD) has recently increased. Since tobacco smoking is the major risk factor for development of COPD, the aim for this study was to examine whether tobacco smoking, pack-years (PY), influenced T1 of the lung parenchyma in asymptomatic current smokers.
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| 8. |
- Bernspång, Elisabeth, et al.
(författare)
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CT lung densitometry in young adults with alpha-1-antitrypsin deficiency
- 2011
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 105:1, s. 74-79
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Tidskriftsartikel (refereegranskat)abstract
- Background: Severe (PiZZ) and moderate (PiSZ) alpha-1-antitrypsin (AAT) deficiency predispose to lung emphysema, especially in smokers. We hypothesized that multi-slice computed tomography (CT) might be superior to pulmonary function tests (PFT) to detect lung emphysema in AAT-deficient individuals at the age of 32 years. Methods: A subgroup of PiZZ and PiSZ individuals identified during the Swedish newborn screening programme in 1972-74 underwent multi-slice CT and PFT at the age of 32 years. From the CT scans the percentile density at 15% (PD15) and the relative area below -910 Hounsfield Units (RA(-910) HU) were calculated. The results of PFT and CT were compared between the AAT-deficient individuals and an age-matched control group. Results: Twenty-five PiZZ, 11 PiSZ and 17 PiMM individuals participated in the study. All Pi subgroups had normal lung function. The mean PD15 was 81 (SD 22) g/L in the PiZZ individuals, 96 (SD 35) g/L in the PiSZ individuals and 79 (SD 17) g/L in the PiMM individuals (ns), and the RA-910 were 30 (SD 18)%, 24 (SD 20)%, and 32 (SD 18)%, respectively (ns). For the never-smoker subgroups, in the PiZZ (n = 23), PiSZ (n = 8) and PiMM (n = 12), the mean PD15 were 95 (SD 35) g/L, 81 (SD 22) g/L, and 75 (SD 12) g/L, respectively (ns). PD15 was significantly correlated to CT derived lung size (r = -0.72; p < 0.001). Conclusions: CT densitometry revealed no signs of emphysema and no differences between the AAT-deficient individuals identified by neonatal screening and age-matched control subjects.
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| 9. |
- Garpered, Sabine, et al.
(författare)
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Measurement of airway inflammation in current smokers by positron emission tomography
- 2019
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 39:6, s. 393-398
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Tidskriftsartikel (refereegranskat)abstract
- Background Accumulation of activated neutrophilic leucocytes is known to increase uptake of F-18-fluorodeoxyglucose (F-18-FDG) into lung tissue. Available evidence suggests that smokers and subjects with chronic obstructive pulmonary disease (COPD) have neutrophilic inflammation in peripheral airways. The aim of this study was to examine whether current smokers have higher lung tissue uptake of F-18-FDG than never-smokers when correcting for air fraction of the lungs. Methods We prospectively recruited 33 current smokers and 33 never-smokers among subjects referred for diagnosis or staging of cancer, other than lung cancer, with combined positron emission tomography/computed tomography (PET/CT) with F-18-FDG. Subjects with focal F-18-FDG uptake or focal CT abnormalities in the lungs were excluded. The lungs were segmented in the CT image, and lung density measured. F-18-FDG uptake was measured in the corresponding volume and corrected for air fraction. Results Lung uptake of F-18-FDG, corrected for air fraction, was 12 center dot 5 and 8 per cent higher in the right and left lungs, respectively, in current smokers than in never-smokers (P<0 center dot 05). Conclusion Abnormal lung tissue uptake of F-18-FDG may be masked by reduced lung density if the uptake is not related to air fraction. Increased uptake of F-18-FDG in lung tissue in current smokers relative to never-smokers may reflect inflammation in peripheral airways. Measurements of F-18-FDG uptake in the lung tissue may be useful for animal and human studies of airways disease in COPD and the relation between airway and systemic inflammation.
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