Extent Of Ground-glass Opacity Research Articles

Clinical course and risk factors for development and progression of interstitial lung disease in primary Sjögren’s syndrome

This single-center, retrospective study aimed to investigate the course and prognostic factors of patients with primary Sjögren syndrome-associated interstitial lung disease (pSS-ILD). We included 120 pSS patients who underwent at least two high-resolution computed tomography (HRCT) scans between 2013 and 2021. Clinical symptoms, laboratory data, HRCT findings, and pulmonary function test results were collected. Two thoracic radiologists reviewed the HRCT findings. In patients with pSS without ILD at baseline (n = 81), no development of ILD was found on follow-up (median, 2.8 years). In patients with pSS-ILD (n = 39), total disease extent, extent of coarse reticulation, and traction bronchiectasis increased on HRCT, whereas the extent of ground glass opacity (GGO) decreased at follow-up (median, 3.2 years) (each p < 0.001). In progressive group of pSS-ILD (48.7%), the extent of coarse reticulation and coarseness score of fibrosis were increased at follow-up (p < 0.05). Usual interstitial pneumonia pattern on CT (OR, 15.237) and follow-up duration (OR, 1.403) were independent risk factors for disease progression in patients with pSS-ILD. In both progressive and non-progressive pSS-ILD, GGO decreased, whereas the extent of fibrosis increased even after treatment with glucocorticoid and/or immunosuppressants. In conclusion, progression occurred in approximately half of the pSS-ILD patients with slow gradual deterioration. Our study identified a definite group of progressive pSS-ILD who did not respond to current anti-inflammatory treatment.

CARE Score on Chest Radiograph at Diagnosis Predicts Early and Late Outcomes Among Lung Transplant Patients with COVID-19

PurposeTo assess the ability of an objective radiographic scoring system to predict outcomes among lung transplant (LT) patients with Coronavirus disease 2019 (COVID-19).MethodsWe included all LT patients diagnosed with COVID-19 during a one-year period (March 2020 to Feb 2021; n=54; median age: 60, 20-73 years; M:F 37:17) in our program. Patient characteristics and laboratory values during the acute illness were reviewed. Chest radiographs at time of COVID-19 diagnosis were scored by extent of ground-glass opacity and consolidation using the CARE score (0-18 for each lung). The CARE score was calculated using only the allograft in single LT and the average of both lungs in bilateral LT. Primary outcome was six-month survival after COVID-19. Hospital complications and one-month survival were secondary outcomes.ResultsA minority of patients had a clear allograft (CARE=0, n=12, 22.2%) at presentation. The median score was 2 (interquartile range 0.5-4.625), indicating mild abnormalities. Demographics, underlying diagnosis, comorbidities, symptoms, and spirometry changes were not associated with the baseline CARE score. Baseline CARE score >5 was strongly associated with development of respiratory failure (91.7% vs 35.7%; OR, 95% CI: 19.8, 2.3-168.7; p=0.001), ICU admission (p<0.001), need for ventilator support (p<0.001), and one-month mortality (41.7% vs 2.4%; OR, 95% CI: 29.4, 2.96-333.3; p=0.001). Overall six-month survival was 81.5%. The CARE score was significantly higher among non-survivors (7.7±4.1 vs 2.2±2.7; p=0.002). Patients with a CARE score>5 at diagnosis were significantly less likely to survive at six-month follow-up (41.7%.vs 92.3%; p<0.001). The CARE score had an excellent area under the curve (86.8%, 74.4%-99.2%; p<0.001) on the Receiver operating characteristic curve for predicting six-month survival after COVID-19.ConclusionThe CARE score at time of COVID-19 diagnosis provides useful prognostic information among patients with LT.

CT Features of Lymphatic Plastic Bronchitis in Adults: Correlation with Multimodality Lymphatic Imaging.

To distinguish CT patterns of lymphatic and nonlymphatic causes of plastic bronchitis (PB) through comparison with lymphatic imaging. In this retrospective study, chest CT images acquired prior to lymphatic workup were assessed in 44 patients with PB from January 2014 to August 2020. The location and extent of ground-glass opacity (GGO) was compared with symptoms and lymphatic imaging. Statistical analysis was performed using descriptive statistics, logistic regression, Pearson correlation coefficient, and unweighted κ coefficient for interobserver agreement. Sensitivity and specificity of GGO for lymphatic PB were calculated. Lymphatic imaging was performed in 44 patients (median age, 52 years ± 21 [IQR]; 23 women): 35 with lymphatic PB and nine with nonlymphatic PB. GGO was more frequently observed in patients with lymphatic PB than in those with nonlymphatic PB (91% [32 of 35] vs 33% [three of nine]; P < .001). Univariate logistic regression confirmed this result by showing that GGO was a significant predictor of lymphatic PB (odds ratio, 21 (95% CI: 3.8, 159.7). The model areas under the receiver operating characteristic curve (AUCs) of GGO unadjusted and adjusted for demographics were 0.79 and 0.86, respectively. The location of GGO correlated with lymphatic imaging and bronchoscopic findings. Overall sensitivity and specificity of GGO for lymphatic PB were 91% (32 of 35; 95% CI: 76, 98) and 67% (six of nine; 95% CI: 30, 93), respectively. Patients with lymphatic PB predominantly had multifocal GGO with or without a "crazy paving" pattern; identification of GGO should prompt lymphatic workup in this frequently misdiagnosed condition.Keywords: Lymphography, Lymphatic, CT, Tracheobronchial Tree, Thorax© RSNA, 2022See also commentary by Kligerman and White in this issue.

Texture-based classification of lung disease patterns in chronic hypersensitivity pneumonitis and comparison to clinical outcomes.

Computer-aided detection algorithms applied to CT lung imaging have the potential to objectively quantify pulmonary pathology. We aim to develop an automatic classification method based on textural features able to classify healthy and pathological patterns on CT lung images and to quantify the extent of each disease pattern in a group of patients with chronic hypersensitivity pneumonitis (cHP), in comparison to pulmonary function tests (PFTs).27 cHP patients were scanned via high resolution CT (HRCT) at full-inspiration. Regions of interest (ROIs) were extracted and labeled as normal (NOR), ground glass opacity (GGO), reticulation (RET), consolidation (C), honeycombing (HB) and air trapping (AT). For each ROI, statistical, morphological and fractal parameters were computed. For automatic classification, we compared two classification methods (Bayesian and Support Vector Machine) and three ROI sizes. The classifier was therefore applied to the overall CT images and the extent of each class was calculated and compared to PFTs. Better classification accuracy was found for the Bayesian classifier and the 16x16 ROI size: 92.1±2.7%. The extent of GGO, HB and NOR significantly correlated with forced vital capacity (FVC) and the extent of NOR with carbon monoxide diffusing capacity (DLCO).Clinical Relevance- Texture analysis can differentiate and objectively quantify pathological classes in the lung parenchyma and may represent a quantitative diagnostic tool in cHP.

The Extent and Diverse Trajectories of Longitudinal Changes in Rheumatoid Arthritis Interstitial Lung Diseases Using Quantitative HRCT Scores

We aimed to validate quantitative high-resolution computed tomography (HRCT) imaging analyses of interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients, and to delineate a broad spectrum of annual longitudinal changes of ILD severity in the RA-ILD cohorts. Retrospective cohort 1 (n = 26) had matched PFT results and prospective cohort 2 (n = 34) were followed for over two years with baseline serum specimen. Automated quantitative analysis of HRCT was expressed as the extent of ground-glass opacity, lung fibrosis, honeycombing, and their summation—the total extent of quantitative ILD (QILD). Higher QILD score was associated with lower pulmonary function especially for DLCO% (ρ = −0.433, p = 0.027). Higher serum level of Krebs von den Lungen 6 were significantly associated with high QILD scores (ρ = 0.400, p = 0.026). Regarding QILD score changes in whole lung, even a single point increase was significantly associated with interval progression detected by the radiologist. Four distinct patterns (improvement, worsening, convex-like, and concave-like) during the 24 months were described by QILD scores. Prolonged disease duration of ILD at baseline was significantly associated with worsening of QILD scores. QILD has the potential to reliably evaluate the dynamic severity changes in patients with RA-ILD.

Baseline High-Resolution CT Findings Predict Acute Exacerbation of Idiopathic Pulmonary Fibrosis: German and Japanese Cohort Study.

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is a major cause of morbidity and death in IPF. However, sensitive predictive factors of AE-IPF have not been well-investigated. To investigate whether high-resolution computed tomographic (HRCT) abnormalities predict AE-IPF in independent ethnic cohorts, this study included 121 patients with IPF (54 German and 67 Japanese; mean age, 68.5 ± 7.6 years). Two radiologists independently visually assessed the presence and extent of lung abnormalities in each patient. Twenty-two (18.2%) patients experienced AE-IPF during the follow-up. The incidence of AE-IPF was significantly higher in the Japanese patients (n = 18, 26.9%) than in the German patients (n = 4, 7.3%, p < 0.01). In the Kaplan–Meier analysis, patients with a larger extent of ground glass opacity (GGO), fibrosis, and traction bronchiectasis experienced an earlier onset of AE-IPF (p = 0.0033, 0.0088, and 0.049, respectively). In the multivariate analysis, a larger extent of GGO and fibrosis on HRCT were independent predictors of AE-IPF (p = 0.026 and 0.037, respectively). Additionally, Japanese ethnicity was independently associated with the incidence of AE-IPF after adjustment for HRCT findings (p = 0.0074). In conclusion, a larger extent of GGO and fibrosis on HRCT and Japanese ethnicity appear to be risk factors for AE-IPF.

Clinical and Radiological Features of Various Variants of Extrinsic Allergic Alveolitis

Objective . To optimize diagnosis of various variants of morphologically verified extrinsic allergic alveolitis (EAA), by determining the most significant clinical and radiological indicators of its development. Material and methods . Examinations were made in 82 patients with morphologically confirmed EAA, including 10 people with acute EAA, 38 with subacute EAA, 26 with chronic EAA, and 8 with recurrent EAA. Their medical history data were studied; physical examination, clinical blood, pulmonary function (PF), and lung diffusing capacity tests, and high-resolution computed tomography (HRCT) of the chest were performed. Transbronchial and/or video-assisted thoracoscopic lung biopsies were used for morphological studies. Results . Four disease course variants were identified. Disease duration, adherence to a specific antigenic effect, and the clinical, radiological, and morphological patterns of the disease were determined for its each variant. Conclusions . 1. Acute EAA is characterized by an abrupt onset and rapid (no more than 3 months) development with a preponderance of intoxication syndrome (Cumulative Index (CI), 2.1 ± 0.2 scores); subacute EAA is characterized by a slower (8.5–10 months) development with a predominance of respiratory symptoms (CI, 2.5 ± 0.1 scores), the steady progression of which is observed in chronic EAA (CI, 2.9 ± 0.2 scores). Recurrent EAA in previously cured patients is accompanied by both syndromes simultaneously (CI, 2.7 ± 0.3). 2. The characteristic feature of acute EAA on HRCT of the chest is the extent of ground-glass opacity in both lungs (more than 3 segments) and perivascular infiltrates; that of subacute EAA is microfocal dissemination; that of chronic EAA is macrofocal changes in the presence of interlobular septal thickening, as well all the development of cystic changes in the subpleural zones. In recurrent EAA, all the listed symptoms may appear. 3. Enlarged intrathoracic lymph nodes are most common in subacute EAA in 45.9% of cases and less common in acute and chronic EAA in 20 and 23.8% of cases, respectively. In all disease variants, lymph node hypertrophy affects the bifurcation and paratracheal groups and less often the bronchopulmonary and tracheobronchial groups; the sizes vary from 11 to 20 mm with means of 13.0 ± 1.2 mm.

Influence of radiologic expertise in detecting lung tumors on chest radiographs.

To analyze the influence of radiologic expertise in detecting lung tumors on chest radiographs. We retrieved posteroanterior chest radiographs and CT examination obtained from 283 patients with solitary primary malignant lung tumors who underwent surgical resection. There were 176 men and 107 women with a mean age of 67.0±9.1 (SD) years (range: 33-88 years). Thirteen first-year post-graduate (PGY-1) trainees and nine pulmonary specialists (three radiologists, three thoracic surgeons, and three pulmonologists) interpreted the chest radiographs. Detection rates among trainees and specialists were compared using Student t test. The total numbers of detected tumors ranged from 103 (36.4%) to 136 (48.1%) with a mean of 127.9±9.1 (45.2±3.2%) in the trainee group, and 137 (48.4%) to 182 (64.3%) with a mean of 161.6±13.1 (57.1±4.6%) in the specialist group; the intergroup difference was statistically significant (P<0.001). Significant intergroup detectability differences of >10% were noted for tumors in the peripheral zone with (i) ground glass opacity (GGO) ratio ≥10% and <70% and any size, or (ii) GGO ratio <10% and size ≤2cm; and for tumors hidden by the mediastinum, heart, or diaphragm with (i) GGO ratio ≥10% and <30% and size >3cm, or (ii) GGO ratio <10% and size >2cm. Our study demonstrates significant differences in lung tumor detectability on chest radiographs between PGY-1 trainees and pulmonary specialists according to tumor size, extent of GGO, and tumor location.

Radiological classification of multiple lung cancers and the prognostic impact based on the presence of a ground glass opacity component on thin-section computed tomography

ObjectivesRevised TNM classification has proposed a new clinical classification of lung cancers with multiple pulmonary sites. However, definition of the radiological findings and their prognostic impacts are still controversial. Therefore, we evaluated the prognostic impact of multiple lung cancers based on the radiologic classifications concluded from findings on thin-section computed tomography. MethodsAmong surgically resected 1440 c-stage I lung cancer patients, 246 (17.1%) with multiple lung tumors were reviewed. All tumors were classified into 3 groups based on the extent of ground glass opacity (GGO), i.e., consolidation tumor ratio (CTR); GGO-dominant (GD; 0≤CTR<0.5), solid-dominant (SD; 0.5≤CTR<1.0) and pure-solid (PS; CTR=1.0). Multiple lung tumors were divided radiologically into 6 groups, and their prognoses were compared with that of c-stage I lung cancer using Cox’s proportional hazard model. ResultsOf all, 198 patients (80.5%) were surgically resected more than two tumors and determined as multiple lung cancers pathologically. The number of patients with GD+GD=73 (30%), GD+SD=54 (22%), GD+PS=53 (21%), SD+SD=12 (5%), SD+PS=20 (8%) and PS+PS=34 (14%). A multivariate analysis revealed that PS+PS group consisted of independently significant prognosticator (p<0.001). The overall survival (OS) was 97.3% in GD+GD, 98.2% in GD+SD, 84.8% in GD+PS, 90.9% in SD+SD, 78.7% in SD+PS and 41.8% in PS+PS groups, showing a significant difference between PS+PS group and the other groups. Furthermore, the OS of 1194 c-stage I lung cancer patients was 78.2%, and the prognosis of PS+PS group was significantly poor compared with that of c-stage I (p<0.001), while OS of the other groups were almost equivalent or much better than the c-stage I. ConclusionsAmong multiple lung cancers, PS+PS group is associated with poor survival, which would contribute to the upstaging of T descriptors. The presence of GGO is extremely important when considering the correlation between radiological classification of multiple lung cancers and its prognosis.

Pulmonary fibrosis and emphysema: Is the emphysema type associated with the pattern of fibrosis?

To investigate whether the predominant emphysema type is associated with the high resolution computed tomography (HRCT) pattern of fibrosis in combined pulmonary fibrosis and emphysema (CPFE). Fifty-three smokers with upper lobe emphysema and lower lobe pulmonary fibrosis on - HRCT - were retrospectively evaluated. Patients were stratified into 3 groups according to the predominant type of emphysema: Centrilobular (CLE), paraseptal (PSE), CLE = PSE. Patients were also stratified into 3 other groups according to the predominant type of fibrosis on HRCT: Typical usual interstitial pneumonia (UIP), probable UIP and nonspecific interstitial pneumonia (NSIP). HRCTs were scored at 5 predetermined levels for the coarseness of fibrosis (Coarseness), extent of emphysema (emphysema), extent of interstitial lung disease (TotExtILD), extent of reticular pattern not otherwise specified (RetNOS), extent of ground glass opacity with traction bronchiectasis (extGGOBx), extent of pure ground glass opacity and extent of honeycombing. HRCT mean scores, pulmonary function tests, diffusion capacity (DLCO) and systolic pulmonary arterial pressure were compared among the groups. The predominant type of emphysema was strongly correlated with the predominant type of fibrosis. The centrilobular emphysema group exhibited a significantly higher extent of emphysema (P < 0.001) and a lower extent of interstitial lung disease (P < 0.002), reticular pattern not otherwise specified (P < 0.023), extent of ground glass opacity with traction bronchiectasis (P < 0.002), extent of honeycombing (P < 0.001) and coarseness of fibrosis (P < 0.001) than the paraseptal group. The NSIP group exhibited a significantly higher extent of emphysema (P < 0.05), total lung capacity (P < 0.01) and diffusion capacity (DLCO) (P < 0.05) than the typical UIP group. The typical UIP group exhibited a significantly higher extent of interstitial lung disease, extent of reticular pattern not otherwise specified, extent of ground glass opacity with traction bronchiectasis, extent of honeycombing and coarseness of fibrosis (0.039 > P > 0.000). Although the pulmonary arterial pressure was higher in typical UIP group relative to the NSIP group, the difference was not statistically significant. In CPFE patients, paraseptal emphysema is associated more with UIP-HRCT pattern and higher extent of fibrosis than centrilobular emphysema.

Evaluation of the extent of ground-glass opacity on high-resolution CT in patients with interstitial pneumonia associated with systemic sclerosis: Comparison between quantitative and qualitative analysis

To verify whether quantitative analysis of the extent of ground-glass opacity (GGO) on high-resolution computed tomography (HRCT) could show a stronger correlation with the therapeutic response of interstitial pneumonia (IP) associated with systemic sclerosis (SSc) compared with qualitative analysis. Seventeen patients with IP associated with SSc received autologous peripheral blood stem cell transplantation (auto-PBSCT) and were followed up using HRCT and pulmonary function tests. Two thoracic radiologists assessed the extent of GGO on HRCT using a workstation. Therapeutic effect was assessed using the change of vital capacity (VC) and diffusing capacity of the lung for carbon monoxide (DLco) before and 12 months after PBSCT. Interobserver agreement was assessed using Spearman's rank correlation coefficient and the Bland-Altman method. Correlation with the therapeutic response between quantitative and qualitative analysis was assessed with Pearson's correlation coefficients. Spearman's rank correlation coefficient showed good agreement, but Bland-Altman plots showed that proportional error could be suspected. Quantitative analysis showed stronger correlation than the qualitative analysis based on the relationships between the change in extent of GGO and VC, and change in extent of GGO and DLco. Quantitative analysis of the change in extent of GGO showed stronger correlation with the therapeutic response of IP with SSc after auto-PBSCT than with the qualitative analysis.

Clinical relevance of ground glass opacity in 105 patients with miliary tuberculosis

After the application of chest computed tomography (CT), ground glass opacity (GGO) was introduced as one of major accompanying findings of miliary tuberculosis (MT) in addition to miliary nodules. However, little is known about whether GGO is associated with the clinical manifestations and outcomes of MT. Therefore, the present study examined the clinical relevance of GGO in patients with MT. Chest radiographs and CT scans of MT patients were retrospectively reviewed. Clinical manifestations and outcomes were compared in terms of the extent of GGO revealed by chest CT. Confirmed 105 MT patients were included. GGO was observed in 70 (67%) patients. MT patients with an extent of GGO >50% (n = 21) had symptoms of shorter duration, more frequent dyspnea, and more pronounced changes in the levels of acute phase reactants. Miliary nodules were less discernible on CT in those with an extent of GGO >50%. MT patients with an extent of GGO >50% were significantly associated with a longer hospital stay (p = 0.02) and with acute respiratory failure (p < 0.001) than those with an extent of GGO ≤ 50%. However, mortality among MT patients was not associated with the extent of GGO. MT patients with an extent of GGO >50% had more rapidly progressive manifestations and a greater potential for delayed diagnosis and poorer prognosis. Nevertheless, mortality was not higher in confirmed MT patients with an extent of GGO >50% than in those with an extent of GGO ≤ 50%.

Diagnostic Performance of the QuantiFERON-TB Gold In-Tube Assay and Factors Associated With Nonpositive Results in Patients With Miliary Tuberculosis

The QuantiFERON-TB Gold In-Tube (QFT-GIT) assay provides suboptimal diagnostic performance in patients with miliary tuberculosis. QFT-GIT results should be carefully interpreted, particularly in patients suspected of having miliary tuberculosis with severe lymphocytopenia or an extent of ground glass opacity (GGO) >50% on chest computed tomography (CT). Diagnostic performance of the QFT-GIT assay was evaluated in 44 patients with miliary tuberculosis. Among these individuals, 30 (68%) had true-positive QFT-GIT results. Severe lymphocytopenia and an extent of GGO >50% on chest CT were independent risk factors for nonpositive QFT-GIT results.

Correlation between pretreatment or follow-up CT findings and therapeutic effect of autologous peripheral blood stem cell transplantation for interstitial pneumonia associated with systemic sclerosis

Purpose To evaluate what is useful among various parameters including CT findings, laboratory parameters (%VC, %DLco, KL-6), patients related data (age, sex, duration of disease) to discriminate between responder and non-responder in patients who received autologous peripheral blood stem cell transplantation (auto-PBSCT) for interstitial pneumonia (IP) with systemic sclerosis (SSc). Method Auto-PBSCT and follow-up of at least one year by chest CT, serum KL-6, %VC, and %DLco were performed in 15 patients for IP with SSc. Analyzed CT findings included extent of ground-glass opacity (GGO), intralobular reticular opacity, number of segments that showed traction bronchiectasis, and presence of honeycombing. We regarded the therapeutic response of patients as responders when TLC or VC increase over 10% or DLco increase more than 15%, otherwise we have classified as non-responder. We applied univariate and multivariate analyses to find the significant indicators to discriminate responders from non-responders. P < 0.05 was considered statistically significant. Results Univariate and multivariate analyses showed that the significant parameter to discriminate responders from non-responders were pretreatment KL-6, presence of honeycombing, extent of GGO, and early change in extent of GGO. Among them, extent of GGO and early change in extent of GGO were the strongest discriminators between responders and non-responders ( P = 0.001, 0.001, respectively). Conclusion Several CT findings and pretreatment KL-6 may be useful to discriminate between responder and non-responder in patients who received auto-PBSCT for IP with SSc.

Effect and Safety of Mycophenolate Mofetil in Idiopathic Pulmonary Fibrosis

Background. Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic interstitial lung disease with ineffective treatment. Mycophenolate mofetil (MMF) is an immunomodulatory agent which inhibits lymphocyte proliferation. Objective. We sought to determine the safety and efficacy profile of MMF in IPF patients. Methods. We retrospectively identified ten patients, who met the ATS/ERS 2000 criteria for IPF and received MMF 2 gr/day for 12 months. All of them had routine laboratory, pulmonary function and radiological (high resolution computed tomography-HRCT) data available and were enrolled in the study. Forced vital capacity (FVC), total lung capacity (TLC), diffusion capacity of the lung for carbon monoxide (DLCO), 6-minute walking distance (6MWD), HRCT scans and routine laboratory data at treatment onset were compared with respective values 12 months after treatment onset. Results. There were no significant alterations in FVC, TLC, DLCO and 6MWD pre- and 6 and 12 months post-treatment. HRCT evaluation showed deterioration of the total extent of disease (P = 0.002) and extent of ground-glass opacity (P = 0.02). No cases of clinically significant infection, leucopenia, or elevated liver enzymes were recorded. Conclusions. MMF is a safe therapeutic modality which failed to show a beneficial effect both in functional and radiological parameters in a small cohort of IPF patients.

Lung Perfusion with Dual-Energy Multi-detector Row CT: Can It Help Recognize Ground Glass Opacities of Vascular Origin?

The aim of this study was to evaluate whether the spectral characterization of the iodine content of lung microcirculation could help identify ground-glass opacity (GGO) of vascular origin. Thirty-five consecutive patients with GGO of bronchioloalveolar (group 1; n = 24) and vascular (group 2; n = 11) origin underwent dual-energy multi-detector computed tomographic angiography of the chest using a standard injection protocol. For each patient, two radiologists evaluated by consensus the presence, location, and extent of GGO on diagnostic computed tomographic scans (ie, contiguous 1-mm-thick averaged images from both tubes) and characteristics of the corresponding areas on perfusion scans. A total of 443 segments with GGO were depicted on the diagnostic scans (group 1, n = 231; group 2, n = 212), always intermingled with areas of normal lung attenuation, with a mean of 12.7 segments with GGO per patient. Areas of GGO were located at the level of the upper lobes (n = 128), middle lobe and/or lingula (n = 81), and lower (n = 234) lobes, involving <25% (n = 165), 25% to 50% (n = 103), 50% to 75% (n = 155), and >75% (n = 20) of the segmental surface. The overall quality of perfusion scans was rated as interpretable in all patients. Perfusion scans depicted areas of hyperattenuation within segments of GGO with a significantly higher frequency in group 2 (211 of 212 [99.5%]) than in group 1 (27 of 231 [12%]) (P < .0001). Hyperattenuated areas of vascular origin were observed to match the areas of GGO in surface (203 of 211 [96%]) and contours (208 of 211 [98.6%]). Dual-energy computed tomography can help recognize GGO of vascular origin.

Acute Pulmonary Embolism: Relationships between Ground-Glass Opacification at Thin-Section CT and Hemodynamics in Pigs

To investigate the link between acute pulmonary embolism (PE) and occurrence of ground-glass opacity (GGO) and the relationships between this occurrence and hemodynamics in an animal model of acute PE. In this animal care committee-approved study, PE was achieved by injecting blood clots through a central venous catheter in five pigs. Thin-section computed tomography (CT) and hemodynamic measurements-mean pulmonary arterial pressure (Ppa), systemic and pulmonary cardiac outputs, effective pulmonary capillary pressure (Pc'), right atrial pressure, and occluded Ppa-were obtained before and after PE was achieved. Severity and extent of GGO were assigned scores subjectively, and lung attenuation was measured on each scan. Measurements were performed every 20 minutes after PE was achieved, for a total duration of 60 minutes. Finally, CT pulmonary angiography was performed. Lung attenuation was measured in unobstructed and obstructed zones. Measurements were compared by using analysis of variance and Student t test when appropriate. Correlations were investigated through Spearman rank correlation test. In the unobstructed lung zones, GGO appeared immediately after PE was achieved, with an increased mean lung attenuation (P < .001). Mean Ppa and Pc' increased immediately after PE was achieved, and Pc' reached 23 mm Hg, a value associated with pulmonary edema. Cardiac output did not change (P = .238). Lung attenuation and subjective score assignment for GGO were significantly correlated with Ppa and Pc' (P < .001 to .002). Acute PE induces GGO in unobstructed lung zones. Given constant cardiac output, GGO is likely to be related to redistribution of blood flow from obstructed to unobstructed lung zones and occurs at a pressure consistent with pulmonary edema.

Appearances of pulmonary focal lesions at 0.5-mm slice thickness computed tomography: comparison with 1-mm slice thickness computed tomography

Aim This study aimed to evaluate the validity of 0.5-mm thin-section computed tomography (CT) for the assessment of pulmonary nodular lesion in comparison with 1-mm CT. Materials and Methods A total of 38 focal lesions from 30 patients, which were scanned with 0.5- and 1.0-mm collimation, were evaluated regarding the extent of ground-glass opacity (GGO) and well-defined margin, and the presence of pleural indentation, spicula, and internal air density. The frequency of each finding was statistically compared between 0.5- and 1-mm CT using the McNemar test. Results No statistically significant difference was observed between 0.5- and 1-mm CT for each finding. Conclusion The use of 0.5-mm CT is not justified if the original collimation of multi-detector row CT is near 1 mm.

Detectability of peripheral lung cancer on chest radiographs: effect of the size, location and extent of ground-glass opacity

The purpose of this study was to evaluate the effect of the size and location of lung tumour and the extent of ground-glass opacity (GGO) on thin-section CT for the detection of peripheral lung cancer on chest radiographs. 100 posteroanterior chest radiographs of peripheral lung cancer 20 mm in diameter or smaller were reviewed retrospectively by two chest radiologists individually. Lung cancer was detectable on chest radiographs in 51 (51%) cases. However, in six cases, the tumour was recognized not as a nodular opacity but as a subpleural linear or localized hazy opacity. The median size of detectable lung cancer (17 mm) was larger than that of undetectable lung cancer (14 mm; p<0.001). The frequency of tumours with extent of GGO less than 70% was 94% in detectable cases and 59% in undetectable cases (p<0.001). The frequency of tumours located in unobscured lung was 94% in detectable cases and 59% in undetectable cases (p<0.001). The detectability of peripheral lung cancer on chest radiographs is influenced by tumour size, location and extent of GGO seen on thin-section CT. It should also be noted that some tumours may not be recognized as a nodular opacity even if they are detectable.

Combined evaluation of preoperative FDG uptake on PET, ground-glass opacity area on CT, and serum CEA level: identification of both low and high risk of recurrence in patients with resected T1 lung adenocarcinoma

Patients with the same pathological stage of lung adenocarcinoma display marked variability in postoperative recurrence. The aim of this study was to predict the postoperative prognosis in patients with small-sized pulmonary adenocarcinoma on the basis of FDG uptake on PET, the extent of ground-glass opacity (GGO) on CT, and serum carcinoembryonic antigen (CEA) levels. We evaluated 87 patients (40 men, 47 women; mean age 64 years, age range 42-84 years) with lung adenocarcinoma of 3.0 cm or smaller. The level of FDG uptake (low or high), the extent of GGO (GGO or solid), and serum CEA levels (<20 ng/ml or > or =20 ng/ml) were correlated with the pathological findings of cell dedifferentiation, aggressiveness, N factor, and the incidence of relapse. The patients were divided into the following four groups: those with the GGO pattern (group I, 13 patients), those with solid pattern and low FDG uptake (group II, 35 patients), those with solid pattern, high FDG uptake, and CEA <20 ng/ml (group III, 32 patients), and those with solid pattern, high FDG uptake, and CEA > or =20 ng/ml (group IV, 7 patients). The incidence of cell dedifferentiation, aggressiveness, and lymph node metastasis were significantly different among the groups (p<0.0001); . The 5-year disease-free survival rates were 100% in group I, 80.1% in group II, 43.7% in group III, and 16.7% in group IV (p<0.0001). Combined evaluation of preoperative FDG uptake, GGO, and serum CEA level may enable patients with T1 lung adenocarcinoma at low risk and at high risk of postoperative recurrence to be identified.