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Objectives Quantitative computed tomography (CT) plays an increasingly important role in phenotyping airway diseases. Lung parenchyma and airway inflammation could be quantified by contrast enhancement at CT, but its investigation by multiphasic examinations is limited. We aimed to quantify lung parenchyma and airway wall attenuation in a single contrast-enhanced spectral detector CT acquisition. Methods For this cross-sectional retrospective study, 234 lung-healthy patients who underwent spectral CT in four different contrast phases (non-enhanced, pulmonary arterial, systemic arterial, and venous phase) were recruited. Virtual monoenergetic images were reconstructed from 40–160 keV, on which attenuations of segmented lung parenchyma and airway walls combined for 5th–10th subsegmental generations were assessed in Hounsfield Units (HU) by an in-house software. The spectral attenuation curve slope between 40 and 100 keV (λHU) was calculated. Results Mean lung density was higher at 40 keV compared to that at 100 keV in all groups (p λHU of lung attenuation was significantly higher in the systemic (1.7 HU/keV) and pulmonary arterial phase (1.3 HU/keV) compared to that in the venous phase (0.5 HU/keV) and non-enhanced (0.2 HU/keV) spectral CT (p p ≤ 0.001). λHU for wall attenuation was significantly higher in the pulmonary arterial (1.8 HU/keV) and systemic arterial (2.0 HU/keV) compared to that in the venous (0.7 HU/keV) and non-enhanced (0.3 HU/keV) phase (p ≤ 0.002). Conclusions Spectral CT may quantify lung parenchyma and airway wall enhancement with a single contrast phase acquisition, and may separate arterial and venous enhancement. Further studies are warranted to analyze spectral CT for inflammatory airway diseases. Key Points • Spectral CT may quantify lung parenchyma and airway wall enhancement with a single contrast phase acquisition. • Spectral CT may separate arterial and venous enhancement of lung parenchyma and airway wall. • The contrast enhancement can be quantified by calculating the spectral attenuation curve slope from virtual monoenergetic images.

Background Recent studies support magnetic resonance angiography (MRA) as a diagnostic tool for pulmonary arterial disease. Purpose To determine MRA image quality and reproducibility, and the dependence of MRA image quality and reproducibility on disease severity in patients with chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). Material and Methods Twenty patients with COPD (mean age 66.5 ± 8.9 years; FEV1% = 42.0 ± 13.3%) and 15 with CF (mean age 29.3 ± 9.3 years; FEV1% = 66.6 ± 15.8%) underwent morpho-functional chest magnetic resonance imaging (MRI) including time-resolved MRA twice one month apart (MRI1, MRI2), and COPD patients underwent non-contrast computed tomography (CT). Image quality was assessed visually using standardized subjective 5-point scales. Contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured by regions of interest. Disease severity was determined by spirometry, a well-evaluated chest MRI score, and by computational CT emphysema index (EI) for COPD. Results Subjective image quality was diagnostic for all MRA at MRI1 and MRI2 (mean score = 4.7 ± 0.6). CNR and SNR were 4 43.8 ± 8.7 and 50.5 ± 8.7, respectively. Neither image quality score nor CNR or SNR correlated with FEV1% or chest MRI score for COPD and CF (r = 0.239–0.248). CNR and SNR did not change from MRI1 to MRI2 ( P = 0.434–0.995). Further, insignificant differences in CNR and SNR between MRA at MRI1 and MRI2 did not correlate with FEV1% nor chest MRI score in COPD and CF (r = −0.238–0.183), nor with EI in COPD (r = 0.100–0.111). Conclusion MRA achieved diagnostic quality in COPD and CF patients and was highly reproducible irrespective of disease severity. This supports MRA as a robust alternative to CT in patients with underlying muco-obstructive lung disease.

Objectives Pulmonary perfusion abnormalities are prevalent in patients with chronic obstructive pulmonary disease (COPD), are potentially reversible, and may be associated with emphysema development. Therefore, we aimed to evaluate the clinical meaningfulness of perfusion defects in percent (QDP) using DCE-MRI. Methods We investigated a subset of baseline DCE-MRIs, paired inspiratory/expiratory CTs, and pulmonary function testing (PFT) of 83 subjects (age = 65.7 ± 9.0 years, patients-at-risk, and all GOLD groups) from one center of the “COSYCONET” COPD cohort. QDP was computed from DCE-MRI using an in-house developed quantification pipeline, including four different approaches: Otsu’s method, k-means clustering, texture analysis, and 80th percentile threshold. QDP was compared with visual MRI perfusion scoring, CT parametric response mapping (PRM) indices of emphysema (PRMEmph) and functional small airway disease (PRMfSAD), and FEV1/FVC from PFT. Results All QDP approaches showed high correlations with the MRI perfusion score (r = 0.67 to 0.72, p r = 0.72, p p Emph (r = 0.70 to 0.75, p Emph (mean difference = 35.85 to 40.40) and PRMfSAD (mean difference = 15.12 to 19.68), but in close agreement when combining both PRM indices (mean difference = 1.47 to 6.03) for all QDP approaches. QDP correlated moderately with FEV1/FVC (r = − 0.54 to − 0.41, p Conclusion QDP is associated with established markers of disease severity and the extent corresponds to the CT-derived combined extent of PRMEmph and PRMfSAD. We propose to use QDP based on Otsu’s method for future clinical studies in COPD. Key Points • QDP quantified from DCE-MRI is associated with visual MRI perfusion score, CT PRM indices, and PFT. • The extent of QDP from DCE-MRI corresponds to the combined extent of PRMEmph and PRMfSAD from CT. • Assessing pulmonary perfusion abnormalities using DCE-MRI with QDP improved the correlations with CT PRM indices and PFT compared to the quantification of pulmonary blood flow and volume.

Interstitial lung diseases (ILDs) comprise over 200 parenchymal lung disorders. Among them, fibrosing ILDs, especially idiopathic pulmonary fibrosis, are associated with a poor prognosis, whereas some other ILDs, such as sarcoidosis, have a much better prognosis. A high proportion manifests as fibrotic ILD (fILD). Lung cancer (LC) is a frequent complication of fILD. Activated fibroblasts are crucial for fibrotic processes in fILD. The aim of this exploratory study was to evaluate the imaging properties of static and dynamic fibroblast activation protein (FAP) inhibitor (FAPI) PET/CT in various types of fILD and to confirm FAP expression in fILD lesions by FAP immunohistochemistry of human fILD biopsy samples and of lung sections of genetically engineered (Nedd4-2(−/−)) mice with an idiopathic pulmonary fibrosislike lung disease. Methods: PET scans of 15 patients with fILD and suspected LC were acquired 10, 60, and 180 min after the administration of 150–250 MBq of a (68)Ga-labeled FAPI tracer (FAPI-46). In 3 patients, dynamic scans over 40 min were performed instead of imaging after 10 min. The SUV(max) and SUV(mean) of fibrotic lesions and LC were measured and CT-density–corrected. Target-to-background ratios (TBRs) were calculated. PET imaging was correlated with CT-based fibrosis scores. Time–activity curves derived from dynamic imaging were analyzed. FAP immunohistochemistry of 4 human fILD biopsy samples and of fibrotic lungs of Nedd4-2(−/−) mice was performed. Results: fILD lesions as well as LC showed markedly elevated (68)Ga-FAPI uptake (density-corrected SUV(max) and SUV(mean) 60 min after injection: 11.12 ± 6.71 and 4.29 ± 1.61, respectively, for fILD lesions and 16.69 ± 9.35 and 6.44 ± 3.29, respectively, for LC) and high TBR (TBR of density-corrected SUV(max) and SUV(mean) 60 min after injection: 2.30 ± 1.47 and 1.67 ± 0.79, respectively, for fILD and 3.90 ± 2.36 and 2.37 ± 1.14, respectively, for LC). SUV(max) and SUV(mean) decreased over time, with a stable TBR for fILD and a trend toward an increasing TBR in LC. Dynamic imaging showed differing time–activity curves for fILD and LC. (68)Ga-FAPI uptake showed a positive correlation with the CT-based fibrosis index. Immunohistochemistry of human biopsy samples and the lungs of Nedd4-2(−/−) mice showed a patchy expression of FAP in fibrotic lesions, preferentially in the transition zone to healthy lung parenchyma. Conclusion: (68)Ga-FAPI PET/CT imaging is a promising new imaging modality for fILD and LC. Its potential clinical value for monitoring and therapy evaluation of fILD should be investigated in future studies.

Background There is a clinical need for imaging-derived biomarkers for the management of chronic obstructive pulmonary disease (COPD). Observed pulmonary T1 (T1 (TE)) depends on the echo-time (TE) and reflects regional pulmonary function. Purpose To investigate the potential diagnostic value of T1 (TE) for the assessment of lung disease in COPD patients by determining correlations with clinical parameters and quantitative CT. Study type Prospective non-randomized diagnostic study. Population Thirty COPD patients (67.7 ± 6.6 years). Data from a previous study (15 healthy volunteers [26.2 ± 3.9 years) were used as reference. Field strength/sequence Study participants were examined at 1.5 T using dynamic contrast-enhanced three-dimensional gradient echo keyhole perfusion sequence and a multi-echo inversion recovery two-dimensional UTE (ultra-short TE) sequence for T1 (TE) mapping at TE1-5 = 70 μsec, 500 μsec, 1200 μsec, 1650 μsec, and 2300 μsec. Assessment Perfusion images were scored by three radiologists. T1 (TE) was automatically quantified. Computed tomography (CT) images were quantified in software (qCT). Clinical parameters including pulmonary function testing were also acquired. Statistical tests Spearman rank correlation coefficients (ρ) were calculated between T1 (TE) and perfusion scores, clinical parameters and qCT. A P-value Results Median values were T1 (TE1-5 ) = 644 ± 78 msec, 835 ± 92 msec, 835 ± 87 msec, 831 ± 131 msec, 893 ± 220 msec, all significantly shorter than previously reported in healthy subjects. A significant increase of T1 was observed from TE1 to TE2 , with no changes from TE2 to TE3 (P = 0.48), TE3 to TE4 (P = 0.94) or TE4 to TE5 (P = 0.02) which demonstrates an increase at shorter TEs than in healthy subjects. Moderate to strong Spearman's correlations between T1 and parameters including the predicted diffusing capacity for carbon monoxide (DLCO, ρ -0.69) were found. Overall, correlations were strongest at TE2 , weaker at TE1 and rarely significant at TE4 -TE5 . Data conclusion In COPD patients, the increase of T1 (TE) with TE occurred at shorter TEs than previously found in healthy subjects. Together with the lack of correlation between T1 and clinical parameters of disease at longer TEs, this suggests that T1 (TE) quantification in COPD patients requires shorter TEs. The TE-dependence of correlations implies that T1 (TE) mapping might be developed further to provide diagnostic information beyond T1 at a single TE. Level of evidence 2 TECHNICAL EFFICACY: Stage 1.

We describe the creation and characterization of a calibration CT mini‐lung‐phantom incorporating simulated airways and ground‐glass densities. Ten duplicate mini‐lung‐phantoms with Three‐Dimensional (3‐D) printed tubes simulating airways and gradated density polyurethane foam blocks were designed and built. Dimensional accuracy and CT numbers were measured using micro‐CT and clinical CT scanners. Micro‐CT images of airway tubes demonstrated an average dimensional variation of 0.038 mm from nominal values. The five different densities of incorporated foam blocks, simulating ground‐glass, showed mean CT numbers (±standard deviation) of −897.0 ± 1.5, −844.1 ± 1.5, −774.1 ± 2.6, −695.3 ± 1.6, and −351.0 ± 3.7 HU, respectively. Three‐Dimensional printing and subtractive manufacturing enabled rapid, cost‐effective production of ground‐truth calibration mini‐lung‐phantoms with low inter‐sample variation that can be scanned simultaneously with the patient undergoing lung quantitative CT.

Objective: Evaluation of software tools for segmentation, quantification, and characterization of fibrotic pulmonary parenchyma changes will strengthen the role of CT as biomarkers of disease extent, evolution, and response to therapy in idiopathic pulmonary fibrosis (IPF) patients. Methods: 418 nonenhanced thin-section MDCTs of 127 IPF patients and 78 MDCTs of 78 healthy individuals were analyzed through 3 fully automated, completely different software tools: YACTA, LUFIT, and IMBIO. The agreement between YACTA and LUFIT on segmented lung volume and 80th (reflecting fibrosis) and 40th (reflecting ground-glass opacity) percentile of the lung density histogram was analyzed using Bland-Altman plots. The fibrosis and ground-glass opacity segmented by IMBIO (lung texture analysis software tool) were included in specific regression analyses. Results: In the IPF-group, LUFIT outperformed YACTA by segmenting more lung volume (mean difference 242 mL, 95% limits of agreement −54 to 539 mL), as well as quantifying higher 80th (76 HU, −6 to 158 HU) and 40th percentiles (9 HU, −73 to 90 HU). No relevant differences were revealed in the control group. The 80th/40th percentile as quantified by LUFIT correlated positively with the percentage of fibrosis/ground-glass opacity calculated by IMBIO (r = 0.78/r = 0.92). Conclusions: In terms of segmentation of pulmonary fibrosis, LUFIT as a shape model-based segmentation software tool is superior to the threshold-based YACTA, tool, since the density of (severe) fibrosis is similar to that of the surrounding soft tissues. Therefore, shape modeling as used in LUFIT may serve as a valid tool in the quantification of IPF, since this mainly affects the subpleural space.

Muco-obstructive lung diseases are characterized by airway obstruction and hyperinflation, which can be quantified by imaging. Our aim was to evaluate µCT for longitudinal quantification of muco-obstructive lung disease in β-epithelial Na+ channel overexpressing ( Scnn1b-TG) mice and of the effects of neutrophil elastase (NE) knockout on its progression. Lungs from wild-type (WT), NE−/−, Scnn1b-TG, and Scnn1b-TG/NE−/− mice were scanned with 9-µm resolution at 0, 5, 14, and 60 days of age, and airway and parenchymal disease was quantified. Mucus adhesion lesions (MAL) were persistently increased in Scnn1b-TG compared with WT mice from 0 days (20.25 ± 6.50 vs. 9.60 ± 2.07, P < 0.05), and this effect was attenuated in Scnn1b-TG/NE−/− mice (5.33 ± 3.67, P < 0.001). Airway wall area percentage (WA%) was increased in Scnn1b-TG mice compared with WT from 14 days onward (59.2 ± 6.3% vs. 49.8 ± 9.0%, P < 0.001) but was similar in Scnn1b-TG/NE−/− compared with WT at 60 days (46.4 ± 9.2% vs. 45.4 ± 11.5%, P = 0.97). Air proportion (Air%) and mean linear intercept ( Lm) were persistently increased in Scnn1b-TG compared with WT from 5 days on (53.9 ± 4.5% vs. 30.0 ± 5.5% and 78.82 ± 8.44 µm vs. 65.66 ± 4.15 µm, respectively, P < 0.001), whereas in Scnn1b-TG/NE−/−, Air% and Lm were similar to WT from birth (27.7 ± 5.5% vs. 27.2 ± 5.9%, P = 0.92 and 61.48 ± 9.20 µm vs. 61.70 ± 6.73 µm, P = 0.93, respectively). Our results suggest that µCT is sensitive to detect the onset and progression of muco-obstructive lung disease and effects of genetic deletion of NE on morphology of airways and lung parenchyma in Scnn1b-TG mice, and that it may serve as a sensitive endpoint for preclinical studies of novel therapeutic interventions for muco-obstructive lung diseases.

Die Computertomographie (CT) bietet durch ihre hohe Detailauflosung und die Moglichkeit der multidimensionalen Rekonstruktion eine zuverlassige Moglichkeit der Diagnostik und Verlaufskontrolle morphologischer Zeichen der Mukoviszidose (zystische Fibrose, CF) der Lunge. Standardisierte Leitlinien zur technischen Durchfuhrung bestehen aktuell noch nicht, werden aber fur verschiedene Altersgruppen diskutiert. Zentral bleibt die Applikation ionisierender Strahlung, die stets – jedoch auch besonders in Hinblick auf uberwiegend junge CF-Patienten – einer strengen rechtfertigenden Indikation bedarf. Der Einsatz von CT-Kontrastmitteln ist meist fur Notfallindikationen erforderlich. In der CT finden sich bereits fruhzeitig typische Lungenveranderungen der CF wie Bronchiektasien, Schleimretentionen („mucus plugging“) oder Zeichen der Uberblahung (Air Trapping). Mit der Zeit wurden verschiedene Bewertungsrichtlinien fur eine systematische Schweregradeinteilung etabliert. Diese dienen nicht nur zur individuellen Krankheitseinschatzung, sondern auch im Rahmen von Studien zur Verlaufsbeurteilung und Therapiekontrolle. Unter der technischen Entwicklung der CT kommen auch zunehmend computerbasierte Nachverarbeitungsprogramme zur halbautomatischen Auswertung und Quantifizierung zum Einsatz. Diese sollen nicht nur den klinischen Alltag erleichtern, sondern auch dazu beitragen, standardisierte und quantitative Protokolle und Auswertungen, z. B. im Rahmen von Studien, zu ermoglichen. Parallel wird nach Alternativen der Bildgebung gesucht. Zunehmende Bedeutung gewinnt die Magnetresonanztomographie (MRT), die durch verbesserte Bildqualitat sowie spezialisierte Protokolle an Bedeutung gewinnt und die CT fur Langzeitverlaufe an zahlreichen spezialisierten Zentren bereits haufig ablost.

There is a clinical need for imaging-derived biomarkers for the management of chronic obstructive pulmonary disease (COPD). Observed pulmonary TTo investigate the potential diagnostic value of TProspective non-randomized diagnostic study.Thirty COPD patients (67.7 ± 6.6 years). Data from a previous study (15 healthy volunteers [26.2 ± 3.9 years) were used as reference.Study participants were examined at 1.5 T using dynamic contrast-enhanced three-dimensional gradient echo keyhole perfusion sequence and a multi-echo inversion recovery two-dimensional UTE (ultra-short TE) sequence for TPerfusion images were scored by three radiologists. TSpearman rank correlation coefficients (ρ) were calculated between TMedian values were TIn COPD patients, the increase of T2 TECHNICAL EFFICACY: Stage 1.

Bronchial thermoplasty (BT) can be considered in the treatment of severe asthma to reduce airway smooth muscle mass and bronchoconstriction. We hypothesized that BT may thus have long-term effects on airway dimensions and air-trapping detectable by quantitative computed tomography (QCT).Paired in- and expiratory CT and inspiratory CT were acquired in 17 patients with severe asthma before and up to two years after bronchial thermoplasty and in 11 additional conservatively treated patients with serve asthma, respectively. A fully automatic software calculated the airways metrics for wall thickness (WT), wall percentage (WP), lumen area (LA) and total diameter (TD). Furthermore, lung air-trapping was quantified by determining the quotient of mean lung attenuation in expiration vs. inspiration (E/I MLA) and relative volume change in the Hounsfield interval -950 to -856 in expiration to inspiration (RVCBT reduced WT for the combined analysis of the 2nd-7th airway generation significantly by 0.06 mm (p = 0.026) and WP by 2.05% (p 0.001), whereas LA and TD did not change significantly (p = 0.147, p = 0.706). No significant changes were found in the control group. Furthermore, E/I MLA and RVCBT significantly reduced airway narrowing and air-trapping in patients with severe asthma. This can be interpreted as direct therapeutic effects caused by a reduction in airway-smooth muscle mass and changes in innervation. A reduction in air-trapping indicates an influence on more peripheral airways not directly treated by the BT procedure.

Objectives To evaluate the prognostic value of fully automatic lung quantification based on spectral computed tomography (CT) and laboratory parameters for combined outcome prediction in COVID-19 pneumonia. Methods CT images of 53 hospitalized COVID-19 patients including virtual monochromatic reconstructions at 40-140keV were analyzed using a fully automated software system. Quantitative CT (QCT) parameters including mean and percentiles of lung density, fibrosis index (FIBI-700, defined as the percentage of segmented lung voxels ≥-700 HU), quantification of ground-glass opacities and well-aerated lung areas were analyzed. QCT parameters were correlated to laboratory and patient outcome parameters (hospitalization, days on intensive care unit, invasive and non-invasive ventilation). Results Best correlations were found for laboratory parameters LDH (r = 0.54), CRP (r = 0.49), Procalcitonin (r = 0.37) and partial pressure of oxygen (r = 0.35) with the QCT parameter 75th percentile of lung density. LDH, Procalcitonin, 75th percentile of lung density and FIBI-700 were the strongest independent predictors of patients’ outcome in terms of days of invasive ventilation. The combination of LDH and Procalcitonin with either 75th percentile of lung density or FIBI-700 achieved a r2 of 0.84 and 1.0 as well as an area under the receiver operating characteristic curve (AUC) of 0.99 and 1.0 for the prediction of the need of invasive ventilation. Conclusions QCT parameters in combination with laboratory parameters could deliver a feasible prognostic tool for the prediction of invasive ventilation in patients with COVID-19 pneumonia.

Resumo Fundamento: A embolia pulmonar aguda (EPA) tem desfecho clínico variável. A angiotomografia computadorizada (angio-CT) é considerada o padrão-ouro para o diagnóstico. Objetivo: Avaliar se o volume vascular pulmonar (VVP) quantificado por software automatizado é um preditor de mortalidade após EPA. Métodos: Estudo de coorte retrospectivo no qual a imagem da angio-CT de 61 pacientes com EPA foi reanalisada. O VVP e o volume pulmonar (VP) foram estimados automaticamente pelo software Yacta. Calculamos o VVP ajustado pela razão: VVP(cm3)/VP(litros). Parâmetros prognósticos clássicos da angio-CT (carga embólica; razão do diâmetro do ventrículo direito/ventrículo esquerdo; razão do diâmetro da artéria pulmonar/aorta; desvio do septo interventricular; infarto pulmonar e refluxo de contraste na veia hepática) foram avaliados. A mortalidade em 1 mês foi o desfecho analisado. Consideramos um valor de p

Quantitative CT analysis allows for measurement of static lung volumes. Objective: To evaluate the value of QCT analysis before and after the use of tiotropium/olodaterol respimat in patients with mild/moderate therapy naive COPD patients. Methods: Patients which newly diagnosed COPD and another radiological finding, which indicated a follow-up CT within 6-12 weeks, were put on tiotropium/olodaterol and followed up. Non-enhanced thin-sections were acquired in paired inspiratory/expiratory breath-hold and quantified using YACTA. Results: 10 patients were enrolled (7males, mean age 64 y.). Mean initial VC was 3,45 l (SD 1,2 l) and RV 3,9 l (SD 1,3 l) measured by bodyplethysmography and VC was 3,2 l (SD 1,1 l) and RV 3,8 l (SD 1,3 l) by QCT. At follow up, the VC improved by 130 ml and RV decreased by480 ml in the body as well in the QCT (VC +210 ml, RV-600ml). IN QCT the air-trapping was reduced by converting severe into mild air-trapping or normalization. The correlations of the measurements were high and were also able to show regional differences of the improvement (fig.1). Conclusions: QCT calculated static lung function measurements correlating high with the lung function measurements before and after a tiotropium/olodaterol Respimat treatment. Additional value might be due to the possibility of analysis of regional aspects for identification of failure or eventually local treatment.

Introduction: Impact of ultra-low-dose (ULD) computed tomography (CT) on quantification of structural disease and structure-function relationships in early Cystic Fibrosis (CF) lung disease have not been studied to date. Aim: To quantify structural lung disease and compare same session standard low radiation dose (LD) and ULD CT with pulmonary function measures in early CF lung disease. Methods: 46 CF subjects (age 11(6-17) yrs) with mild lung disease (FEV1≥70%pred) performed multiple breath washout (MBW), and spirometry directed paired inspiratory/expiratory CT with LD (CTDIvol: 1.23 mGy) and ULD (CTDIvol: 0.22 mGy). Quantification was performed automatically by validated institutional CT software. Results: Effective radiation dose was reduced by 78% in ULD vs. LD. Rates of abnormality were highest for CT and MBW and lowest for spirometry. Strong correlations were observed between LD and ULD readouts (gas trapping r=0.91, p

Aim Light microscopy is used as template in the evaluation and further development of medical imaging methods. Tissue shrinkage caused by histological processing is known to influence lung tissue dimensions. In diagnosis of COPD, computed tomography (CT) is widely used for automated airway measurement. The aim of this study was to compare histological and computed tomographic measurements of pig lung bronchi. Methods Airway measurements of pig lungs were performed after freezing under controlled inflation pressure in a liquid nitrogen bath. The wall thickness of seven bronchi was measured via Micro-CT and CT using the integral-based method (IBM) and the full-width-at-half-maximum method (FWHM) automatically and histologically on frozen and paraffin sections. Statistical analysis was performed using the Wilcoxon test, Pearson's correlation coefficient with a significance level at p, Automated measurement techniques advance diagnosis of lung diseases. Pig bronchi wall size varies between Micro-CT, CT IBM, CT FWHM and histology. CT IBM is closest to histological results, followed by Micro-CT. CT FWHM differs highly from all other groups. https://bit.ly/3iRXSrv

IntroductionQuantitative analysis of multi-detector computed tomography (MDCT) plays an increasingly important role in assessing airway disease. Depending on the algorithms used, airway dimensions may be over- or underestimated, primarily if contrast material was used. Therefore, we tested a modified integral-based method (IBM) to address this problem.MethodsTemporally resolved cine-MDCT was performed in seven ventilated pigs in breath-hold during iodinated contrast material (CM) infusion over 60s. Identical slices in non-enhanced (NE), pulmonary-arterial (PA), systemic-arterial (SA), and venous phase (VE) were subjected to an in-house software using a standard and a modified IBM. Total diameter (TD), lumen area (LA), wall area (WA), and wall thickness (WT) were measured for ten extra- and six intrapulmonary airways.ResultsThe modified IBM significantly reduced TD by 7.6%, LA by 12.7%, WA by 9.7%, and WT by 3.9% compared to standard IBM on non-enhanced CT (pConclusionsThe modified IBM can optimize airway wall segmentation and reduce the influence of CM on quantitative CT. This allows a more precise measurement as well as potentially the comparison of enhanced with non-enhanced scans in inflammatory airway disease.

Novel therapeutic options in chronic obstructive pulmonary disease (COPD) require delicate patient selection and thus demand for expert radiologists visually and quantitatively evaluating high-resolution computed tomography (CT) with additional functional acquisitions such as paired inspiratory-expiratory scans or dynamic airway CT. The differentiation between emphysema-dominant and airway-dominant COPD phenotypes by imaging has immediate clinical value for patient management. Assessment of emphysema severity, distribution patterns, and fissure integrity are essential for stratifying patients for different surgical and endoscopic lung volume reduction procedures. This is supported by quantitative software-based postprocessing of CT data sets, which delivers objective emphysema and airway remodelling metrics. However, the significant impact of scanning and reconstruction parameters, as well as intersoftware variability still hamper comparability between sites and studies. In earlier stage COPD imaging, it is less clear as to what extent quantitative CT might impact decision making and therapy follow-up, as emphysema progression is too slow to realistically be useful as a mid-term outcome measure in an individual, and longitudinal data on airway remodelling are still very limited.

Acute pulmonary embolism (APE) has a variable clinical outcome. Computed tomography pulmonary angiography (CTPA) is the gold standard for this diagnosis.To evaluate if the pulmonary vascular volume (PVV) quantified by automated software is a mortality predictor after APE.Retrospective cohort study where the CTPA imaging of 61 patients with APE was reanalyzed. Pulmonary vascular volume (PVV) and pulmonary volume (PV) were automatically estimated using the Yacta software. We calculated the adjusted PVV by the ratio: PVV(cm3)/PV(liters). Classical prognostic CTPA parameters (clot load index, right ventricle/left ventricle diameter ratio, pulmonary artery/aorta diameter ratio, ventricular septal bowing, pulmonary infarction and reflux of contrast into the hepatic vein) were assessed. The outcome assessed was one-month mortality. We considered a p-value0.05 as statistically significant.Seven deaths (11%) occurred at one month among these 61 patients. PVV23cm3/L was an independent predictor of one-month mortality in the univariate [odds ratio (OR): 26; 95% confidence interval (CI): 3-244; p=0.004] and multivariate analyses [adjusted OR: 19; 95%CI: 1.3-270; p=0.03]. The classical CTPA parameters were not associated with one-month mortality in this sample. The PVV23cm3/L showed a sensitivity of 86%, a specificity of 82%, a negative predictive value of 94% and a positive predictive value of 64% to identify the patients who died.PVV23cm3/L was an independent predictor of one-month mortality after APE. This parameter showed better prognostic performance than other classical CTPA findings. (Arq Bras Cardiol. 2020; 115(5):809-818).A embolia pulmonar aguda (EPA) tem desfecho clínico variável. A angiotomografia computadorizada (angio-CT) é considerada o padrão-ouro para o diagnóstico.Avaliar se o volume vascular pulmonar (VVP) quantificado por software automatizado é um preditor de mortalidade após EPA.Estudo de coorte retrospectivo no qual a imagem da angio-CT de 61 pacientes com EPA foi reanalisada. O VVP e o volume pulmonar (VP) foram estimados automaticamente pelo software Yacta. Calculamos o VVP ajustado pela razão: VVP(cm3)/VP(litros). Parâmetros prognósticos clássicos da angio-CT (carga embólica; razão do diâmetro do ventrículo direito/ventrículo esquerdo; razão do diâmetro da artéria pulmonar/aorta; desvio do septo interventricular; infarto pulmonar e refluxo de contraste na veia hepática) foram avaliados. A mortalidade em 1 mês foi o desfecho analisado. Consideramos um valor de p0,05 como estatisticamente significativo.Sete mortes (11%) ocorreram entre os 61 pacientes durante 1 mês de seguimento. O VVP ajustado23cm3/L foi um preditor independente de mortalidade na análise univariada (odds ratio [OR]: 26; intervalo de confiança de 95% [IC95%]: 3-244; p=0,004) e na análise multivariada (OR ajustado: 19 [IC95%: 1,3-270]; p=0,03). Os parâmetros clássicos da angio-CT não foram associados à mortalidade em 1 mês nesta amostra. O VVP ajustado23cm3/L apresentou sensibilidade de 86%, especificidade de 82%, valor preditivo negativo de 94% e valor preditivo positivo de 64% para identificação dos pacientes que morreram.VVP ajustado23cm3/L foi um preditor independente de mortalidade após EPA. Esse parâmetro mostrou melhor desempenho prognóstico do que os outros achados clássicos da angio-CT. (Arq Bras Cardiol. 2020; 115(5):809-818).

Background Radiologic evidence of air trapping (AT) on expiratory computed tomography (CT) scans is associated with early pulmonary dysfunction in patients with cystic fibrosis (CF). However, standard techniques for quantitative assessment of AT are highly variable, resulting in limited efficacy for monitoring disease progression. Objective To investigate the effectiveness of a convolutional neural network (CNN) model for quantifying and monitoring AT, and to compare it with other quantitative AT measures obtained from threshold-based techniques. Materials and methods Paired volumetric whole lung inspiratory and expiratory CT scans were obtained at four time points (0, 3, 12 and 24 months) on 36 subjects with mild CF lung disease. A densely connected CNN (DN) was trained using AT segmentation maps generated from a personalized threshold-based method (PTM). Quantitative AT (QAT) values, presented as the relative volume of AT over the lungs, from the DN approach were compared to QAT values from the PTM method. Radiographic assessment, spirometric measures, and clinical scores were correlated to the DN QAT values using a linear mixed effects model. Results QAT values from the DN were found to increase from 8.65% ± 1.38% to 21.38% ± 1.82%, respectively, over a two-year period. Comparison of CNN model results to intensity-based measures demonstrated a systematic drop in the Dice coefficient over time (decreased from 0.86 ± 0.03 to 0.45 ± 0.04). The trends observed in DN QAT values were consistent with clinical scores for AT, bronchiectasis, and mucus plugging. In addition, the DN approach was found to be less susceptible to variations in expiratory deflation levels than the threshold-based approach. Conclusion The CNN model effectively delineated AT on expiratory CT scans, which provides an automated and objective approach for assessing and monitoring AT in CF patients.