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Purpose: Focal interstitial fibrosis (FIF) manifesting as a persistent part-solid nodule (PSN) has been mistakenly treated surgically due to similar imaging features to invasive adenocarcinoma (ADC). The purpose of this study was to observe predictive imaging features correlated with FIF through CT morphologic analysis., Materials and Methods: From January 2009 to December 2020, 44 patients with surgically proven FIF in a single institution were enrolled and compared with 88 ADC patients through propensity score matching. Patient characteristics and CT morphologic analysis of persistent PSNs were used to identify predictive imaging features of FIF. Receiver operating characteristic (ROC) curve analysis was used to quantify the performance of imaging features., Results: A total of 132 patients with 132 PSNs (44 FIF, 88 ADC; mean age, 67.7±7.58; 75 females) were involved in our analysis. Multivariable analysis demonstrated that preserved peritumoral vascular margin (preserved vascular margin), preserved secondary pulmonary lobule margin (preserved lobular margin), and lower coronal to axial ratio (C/A ratio; cutoff: 1.005) were significant independent predictors of FIF ( P< 0.05). ROC curve analysis to evaluate the predictive value of the logistic model based on the imaging features of FIF, and the AUC value was 0.881., Conclusion: CT imaging features of preserved vascular margin, preserved lobular margin, and lower C/A ratio (cutoff, <1.005) might be helpful imaging features in discriminating FIF over ADC among persistent PSN in clinical practice., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: This study aims to develop artificial intelligence (AI) system to automatically classify patients with maxillary sinus fungal ball (MFB), chronic rhinosinusitis (CRS), and healthy controls (HCs)., Methods: We collected 512 coronal image sets from ostiomeatal unit computed tomography (OMU CT) performed on subjects who visited a single tertiary hospital. These data included 254 MFB, 128 CRS, and 130 HC subjects and were used for training the proposed AI system. The AI system takes these 1024 sets of half CT images as input and classifies these as MFB, CRS, or HC. To optimize the classification performance, we adopted a 3-D convolutional neural network of ResNet 18. We also collected 64 coronal OMU CT image sets for external validation, including 26 MFB, 18 CRS, and 20 HCs from subjects from another referral hospital. Finally, the performance of the developed AI system was compared with that of the otolaryngology resident physicians., Results: Classification performance was evaluated using internal 5-fold cross-validation (818 training and 206 internal validation data) and external validation (128 data). The area under the receiver operating characteristic over the internal 5-fold cross-validation and the external validation was 0.96 ±0.006 and 0.97 ±0.006, respectively. The accuracy of the internal 5-fold cross-validation and the external validation was 87.5 ±2.3% and 88.4 ±3.1%, respectively. As a result of performing a classification test on external validation data from six otolaryngology resident physicians, the accuracy was obtained as 84.6 ±11.3%., Conclusions: This AI system is the first study to classify MFB, CRS, and HC using deep neural networks to the best of our knowledge. The proposed system is fully automatic but performs similarly to or better than otolaryngology resident physicians. Therefore, we believe that in regions where otolaryngology specialists are scarce, the proposed AI will perform sufficiently effective diagnosis on behalf of doctors., Competing Interests: The authors have declared that no competing interests exist.

Background: The Korean Society of Thoracic Radiology (KSTR) recently constructed a nation-wide coronavirus disease 2019 (COVID-19) database and imaging repository, referred to the Korean imaging cohort of COVID-19 (KICC-19) based on the collaborative efforts of its members. The purpose of this study was to provide a summary of the clinico-epidemiological data and imaging data of the KICC-19., Methods: The KSTR members at 17 COVID-19 referral centers retrospectively collected imaging data and clinical information of consecutive patients with reverse transcription polymerase chain reaction-proven COVID-19 in respiratory specimens from February 2020 through May 2020 who underwent diagnostic chest computed tomography (CT) or radiograph in each participating hospital., Results: The cohort consisted of 239 men and 283 women (mean age, 52.3 years; age range, 11-97 years). Of the 522 subjects, 201 (38.5%) had an underlying disease. The most common symptoms were fever (n = 292) and cough (n = 245). The 151 patients (28.9%) had lymphocytopenia, 86 had (16.5%) thrombocytopenia, and 227 patients (43.5%) had an elevated CRP at admission. The 121 (23.4%) needed nasal oxygen therapy or mechanical ventilation (n = 38; 7.3%), and 49 patients (9.4%) were admitted to an intensive care unit. Although most patients had cured, 21 patients (4.0%) died. The 465 (89.1%) subjects underwent a low to standard-dose chest CT scan at least once during hospitalization, resulting in a total of 658 CT scans. The 497 subjects (95.2%) underwent chest radiography at least once during hospitalization, which resulted in a total of 1,475 chest radiographs., Conclusion: The KICC-19 was successfully established and comprised of 658 CT scans and 1,475 chest radiographs of 522 hospitalized Korean COVID-19 patients. The KICC-19 will provide a more comprehensive understanding of the clinical, epidemiological, and radiologic characteristics of patients with COVID-19., Competing Interests: Soon Ho Yoon is the chief medical officer of MEDICALIP, Co. Ltd. Other authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Target lung tissue selection remains a challenging task to perform for treating severe emphysema with lung volume reduction (LVR). In order to target the treatment candidate, the percentage of low attenuation volume (LAV%) representing the proportion of emphysema volume to whole lung volume is measured using computed tomography (CT) images. Although LAV% have shown to have a correlation with lung function in patients with chronic obstructive pulmonary disease (COPD), similar measurements of LAV% in whole lung or lobes may have large variations in lung function due to emphysema heterogeneity. The functional information of regional emphysema destruction is required for supporting the choice of optimal target. The purpose of this study is to develop an emphysema heterogeneity descriptor for the three-dimensional emphysematous bullae according to the size variations of emphysematous density (ED) and their spatial distribution. The second purpose is to derive a predictive model of airflow limitation based on the regional emphysema heterogeneity. Deriving the bullous representation and grouping them into four scales in the upper and lower lobes, a predictive model is computed using the linear model fitting to estimate the severity of lung function. A total of 99 subjects, 87 patients with mild to very severe COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I~IV) and 12 control participants with normal lung functions (forced expiratory volume in one second (FEV 1 )/forced vital capacity (FVC) > 0.7) were evaluated. The final model was trained with stratified cross-validation on randomly selected 75% of the dataset (n = 76) and tested on the remaining dataset (n = 23). The dispersed cases of LAV% inconsistent with their lung function outcome were evaluated, and the correlation study suggests that comparing to LAV of larger bullae, the widely spread smaller bullae with equivalent LAV has a larger impact on lung function. The testing dataset has the correlation of r = -0.76 (p < 0.01) between the whole lung LAV% and FEV 1 /FVC, whereas using two ED % of scales and location-dependent variables to predict the emphysema-associated FEV 1 /FVC, the results shows their correlation of 0.82 (p < 0.001) with clinical FEV 1 /FVC.

Purpose To identify the features at CT that are predictive of spread through air spaces (STAS) in surgically resected lung adenocarcinomas. Materials and Methods For this retrospective study, presence of STAS was evaluated in 948 consecutive patients who underwent surgical resection for lung adenocarcinoma from April 2015 to December 2016. Patients who were positive for STAS and negative for STAS were matched at a ratio of 1:2 by using patient variables (age, sex, and smoking status). CT features (ie, percentage of solid component, maximum diameter of solid component, lesion density, location, margin, shape, pseudocavity, calcification, central low attenuation, ill-defined peripheral opacity, air bronchogram, satellite lesions, and pleural retraction) were analyzed by using multivariable logistic regression and receiver operating characteristic curves. Results The final study population consisted of 276 patients (mean age, 59 years; age range, 32-78 years) including 129 men (mean age, 60 years; age range, 36-78 years) and 147 women (mean age, 59 years; age range, 32-78 years). Ninety-two patients were positive for STAS and 184 patients were negative for STAS. STAS was more common in solid tumors (71 of 92; 77%) than in part-solid (21 of 92; 23%) or ground-glass lesions (0 of 92; 0%) (P < .001). STAS was also associated with central low attenuation, ill-defined opacity, air bronchogram, and percentage of solid component (all P < .001). Percentage of solid component was an independent predictor of STAS (odds ratio, 1.06; 95% confidence interval: 1.03, 1.08) and a cut-off value of 90% showed a discriminatory power with a sensitivity of 89.2% and a specificity of 60.3%. Conclusion Percentage of solid component was independently associated with spread through air spaces in lung adenocarcinomas. © RSNA, 2018 Online supplemental material is available for this article.

Purpose: To evaluate serial computed tomography (CT) findings of pulmonary mucormycosis correlated with peripheral blood absolute neutrophil count (ANC)., Materials and Methods: Between February 1997 and June 2016, 20 immunocompromised patients (10 males, 10 females; mean age, 48.9 years) were histopathologically diagnosed as pulmonary mucormycosis. On initial (n=20) and follow-up (n=15) CT scans, the patterns of lung abnormalities and their changing features on follow-up scans were evaluated, and the pattern changes were correlated with ANC changes., Results: All patients were immunocompromised. On initial CT scans, nodule (≤3cm)/mass (>3cm) or consolidation with surrounding ground-glass opacity halo (18/20, 90%)) was the most common pattern. On follow-up CT, morphologic changes (13/15, 87%) could be seen and they included reversed halo (RH) sign, central necrosis, and air-crescent sign. Although all cases did not demonstrate the regular morphologic changes at the same timeline, various combinations of pattern change could be seen in all patients. Sequential morphologic changes were related with recovering of ANC in 13 of 15 patients., Conclusion: Pulmonary mucormycosis most frequently presents as consolidation or nodule/mass with halo sign at CT. Morphologic changes into RH sign, central necrotic cavity or air-crescent sign occur with treatment and recovery of ANC., Key Points: • Pulmonary mucormycosis showed various CT-morphology including CT halo sign • Pulmonary mucormycosis had trends of serial morphologic changes on follow-ups • Recovery of absolute neutrophil count changed CT-morphology of mucormycosis in immune-compromised patients.

The histological subtypes by peripheral tumor location remain uncharacterized in COPD patients with emphysema. We investigated histologic subtypes of peripheral lung cancers based on the context of heterogeneous emphysema distribution in patients with airflow limitation and CT-determined emphysema. A retrospective, cross-sectional study was conducted using data from 754 patients with airflow limitation and newly-diagnosed primary lung cancers from February 2013 to February 2015. Of these, 230 patients had emphysema, as determined by computed tomography software designed to quantify emphysema. Among the 230 patients, the most common subtype in central lesions (n=84) was squamous cell carcinoma (SCC) (n=64/84, 76%). Adenocarcinoma (ADC) was more frequently observed in peripheral lesions (n=146) than central lesions (58/146 [40%] vs. 4/84 [5%], p<0.001). In peripheral lesions, ADC was more frequently seen in areas without emphysema than emphysema areas (43/74 [58%] vs. 15/72 [21%], p<0.001), while SCC was more frequently found in emphysema areas than areas without emphysema (44/72 [61%] vs. 13/74 [18%], p<0.001). These associations persisted with adjustments for age, sex, smoking status and forced expiratory volume in 1s. In patients with both airflow limitation and CT-determined emphysema, the main histological subtype of peripheral lung cancer was SCC in emphysema areas and ADC in areas without emphysema., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Objective: To differentiate smoking-related interstitial fibrosis (SRIF) from usual interstitial pneumonia (UIP) with emphysema on CT in combined pulmonary fibrosis and emphysema (CPFE) patients., Materials and Methods: This study was approved by the institutional review board and informed consent was waived. We included 65 patients who underwent lung biopsy under the suspicion of UIP pattern on HRCT, and after radiologic-pathologic correlation, they were divided into three groups: UIP without emphysema (n = 30), UIP with emphysema (n = 26), and SRIF (n = 9). The quantitative extent of emphysema in the entire lung was visually assessed and fibrotic patterns were qualitatively analyzed based on six characteristics (asymmetry, juxta-subpleural sparing, emphysema beside the honeycombing area, absence of ground grass attenuation/reticulation in honeycombing area, inhomogeneous honeycombing, and absence of honeycombing in the upper lobes). Kaplan-Meier analysis was used for survival analysis, and logistic regression with a receiver operating characteristic curve was used to predict the possibility of SRIF., Results: In qualitative analysis of fibrotic patterns, SRIF tended to exhibit more than three of six fibrotic features, whereas UIP with emphysema demonstrated about two of these characteristics (p = 0.035). In addition, SRIF had a higher extent of emphysema than UIP with emphysema when they have same amount of fibrosis (p = 0.014). In patients with SRIF, 5-year survival rate was 85.7%, while it was 40.7% in UIP with emphysema patients (p = 0.035)., Conclusion: Fibrotic CT patterns and survival rate differed between SRIF and UIP with emphysema among CPFE patients, which explains the variable prognosis of CPFE., Competing Interests: The authors have declared that no competing interests exist.

No study has been published on aortic valve calcification (AVC) extent at lung cancer screening low-dose CT (LDCT) and its relationship with aortic stenosis (AS). The purpose of this study was to estimate the cutoff value of AVC on LDCT for detecting AS in asymptomatic Asian subjects. Six thousand three hundred thirty-eight subjects (mean age, 55.9 years ± 8.6) self-referred to health-promotion center underwent LDCT, coronary calcium scoring CT (CSCT), and echocardiography. AVC was quantified using Agatston methods on CT. AVC extent on LDCT was compared with that on CSCT, and AVC threshold for diagnosing AS was calculated. Clinical factors associated with AS and AVC were sought.AVC was observed in 403 subjects (64.9 years ± 8.7) on LDCT (6.4%), and AVC score measured from LDCT showed strong positive correlation with that from CSCT (r = 0.83, P < 0.0001). Of 403 subjects, 40 (10%) were identified to have AS on echocardiography. Cutoff value of AVC score for detecting AS was 138.37 with sensitivity of 90.0% and specificity 83.2%. On multivariate analysis, age (odds ratio [OR] = 1.10, 95% CI: 1.09-1.12) and hypertension (OR = 1.39, 95% CI: 1.10-1.76) were associated with the presence of AVC, whereas AVC extent at LDCT (OR = 104.32, 95% CI: 16.16-673.70) was the only significant clinical factor associated with AS; AVC extent on LDCT (OR = 104.32, 95% CI: 16.16-673.70) was the significant clinical factor associated with AS.The AVC extent on LDCT is significantly related to the presence of AS, and we recommend echocardiography for screening AS based on quantified AVC values on LDCT.

Objective: To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images., Materials and Methods: This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses., Results: Coronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Measured coronary calcium volumes from VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Among the three VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p < 0.001 for all pairs)., Conclusion: The use of VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC.

Objective: To determine the patho-mechanism of pleural effusion or hydropneumothorax in Mycobacterium avium complex (MAC) lung disease through the computed tomographic (CT) findings., Materials and Methods: We retrospectively collected data from 5 patients who had pleural fluid samples that were culture-positive for MAC between January 2001 and December 2013. The clinical findings were investigated and the radiological findings on chest CT were reviewed by 2 radiologists., Results: The 5 patients were all male with a median age of 77 and all had underlying comorbid conditions. Pleural fluid analysis revealed a wide range of white blood cell counts (410-100690/µL). The causative microorganisms were determined as Mycobacterium avium and Mycobacterium intracellulare in 1 and 4 patients, respectively. Radiologically, the peripheral portion of the involved lung demonstrated fibro-bullous changes or cavitary lesions causing lung destruction, reflecting the chronic, insidious nature of MAC lung disease. All patients had broncho-pleural fistulas (BPFs) and pneumothorax was accompanied with pleural effusion., Conclusion: In patients with underlying MAC lung disease who present with pleural effusion, the presence of BPFs and pleural air on CT imaging are indicative that spread of MAC infection is the cause of the effusion.

Background: Little attention has been paid to the initial and follow-up computed tomography (CT) features in primary multi-drug resistant tuberculosis (pMDR-TB) setting., Purpose: To describe serial CT findings and clinical course of pMDR-TB with antibiotic treatment., Material and Methods: For the last 10 years, 340 MDR-TB patients were managed in a tertiary referral hospital. Among them, we included 44 (27 men, 17 women; mean age, 40 years; age range, 20-81 years) pMDR-TB patients; 37 treated with chemotherapy only and seven treated with medical therapy plus surgery. CT findings were evaluated regarding tree-in-bud sign, acinar nodule, peribronchial, segmental or lobar consolidation and cavity, and their extent. Sputum negative conversion rates and serial CT scores were assessed. To compare changes in disease extent between initial and follow-up CT studies, paired t-test was performed., Results: Two most frequent patterns of lung abnormality were tree-in-bud sign (37 of 44, 84.1%) and acinar nodule (41 of 44, 93.2%). Among 37 patients treated with chemotherapy only, 36 showed negative sputum conversion within 3 months after second-line drug commencement, maintained for >12 months. The other seven undergoing surgery during medical treatment showed excellent outcome with negative conversion achieved within one month after surgery and maintained for >12 months. CT scores showed significant decrease on serial CT studies (P < 0.001) in all., Conclusion: In pMDR-TB, two most frequent abnormal CT patterns are tree-in-bud sign and acinar nodule. In 98% of patients, negative sputum conversion is achieved, and CT score also shows decrease in extent after TB chemotherapy., (© The Foundation Acta Radiologica 2015.)

Background: Recent reports have suggested the association between emphysema and cardiovascular disease (CVD); however, there are few reports regarding association of emphysema severity with metabolic syndrome and its components representing CVD risk factors., Methods: A retrospective cross-sectional study was performed in 2814 adult male subjects over age 40 who visited the Health Promotion Center in Samsung Medical Center for a health checkup program., Results: We classified patients according to the quintiles of forced expiratory volume in 1 sec (FEV1) and emphysema index (EI). FEV1 percentage predicted values (% pred) was inversely associated with prevalence of metabolic syndrome and most of its components, such as abdominal obesity, hypertension, fasting hyperglycemia, and low high-density lipoprotein cholesterol. Although there was no association between prevalence of metabolic syndrome and EI, hypertension was positively associated with EI (P<0.001) and high triglycerides (TGs) were inversely associated with EI (P=0.021). These associations persisted after adjustment of other variables (P<0.001 in hypertension and P=0.039 in high TGs)., Conclusion: The computed tomography-determined EI has a complex association with components of metabolic syndrome that is associated with increased prevalence of hypertension but decreased prevalence of high TGs, whereas FEV1 (% pred) has an inverse association with metabolic syndrome and most of its components with consistent direction.

Background and Objective: Subcentimeter nodules without change in size during long-term follow-up period (for minimum 2 years) are assumed as benign lesions. However, the 2-year stability rule has not been fully verified so far and is still questionable. Thus, we aimed to retrospectively investigate long-term follow-up results for 2-year stable subcentimeter nodules at screening low-dose computed tomography (LDCT)., Methods: A total of 635 subjects having had follow-up LDCTs for the initial 2-year screening period and additional 3 years thereafter and having had non-calcified subcentimeter nodules were included. By using computed tomography (CT) nodule volumetry software, we measured interval changes in nodule volume., Results: A total of 1107 subcentimeter nodules (1037 solid, 70 ground-glass opacity nodules (GGNs)) were detected at baseline CT. Of 1037 solid nodules, 1032 showed no growth during the initial 2-year and 5-year follow-up period. Fifty-nine GGNs were stable for initial 2 years, but two (3.4%) were later proved as adenocarcinomas. Among five solid nodules that showed growth during the initial 2-year follow-up period, one (20%) proved to be an adenocarcinoma, whereas four (36.4%) of 11 GGNs that demonstrated growth were diagnosed as lung cancers., Conclusions: All solid subcentimeter nodules having initial 2-year stability at screening LDCT can be considered benign because none shows growth at further follow-up CT. On the other hand, subcentimeter GGNs have more chance of growth than solid nodules and need further follow-up CT for more than 2 years., (© 2014 Asian Pacific Society of Respirology.)

Objective: To compare the diagnostic performance of light emitting diode (LED) backlight monitors and cold cathode fluorescent lamp (CCFL) monitors for the interpretation of digital chest radiographs., Materials and Methods: We selected 130 chest radiographs from health screening patients. The soft copy image data were randomly sorted and displayed on a 3.5 M LED (2560 × 1440 pixels) monitor and a 3 M CCFL (2048 × 1536 pixels) monitor. Eight radiologists rated their confidence in detecting nodules and abnormal interstitial lung markings (ILD). Low dose chest CT images were used as a reference standard. The performance of the monitor systems was assessed by analyzing 2080 observations and comparing them by multi-reader, multi-case receiver operating characteristic analysis. The observers reported visual fatigue and a sense of heat. Radiant heat and brightness of the monitors were measured., Results: Measured brightness was 291 cd/m(2) for the LED and 354 cd/m(2) for the CCFL monitor. Area under curves for nodule detection were 0.721 ± 0.072 and 0.764 ± 0.098 for LED and CCFL (p = 0.173), whereas those for ILD were 0.871 ± 0.073 and 0.844 ± 0.068 (p = 0.145), respectively. There were no significant differences in interpretation time (p = 0.446) or fatigue score (p = 0.102) between the two monitors. Sense of heat was lower for the LED monitor (p = 0.024). The temperature elevation was 6.7℃ for LED and 12.4℃ for the CCFL monitor., Conclusion: Although the LED monitor had lower maximum brightness compared with the CCFL monitor, soft copy reading of the digital chest radiographs on LED and CCFL showed no difference in terms of diagnostic performance. In addition, LED emitted less heat.

Objective: To evaluate tumor responses in patients treated with anti-angiogenic agents for non-small cell lung cancer (NSCLC) by assessing intratumoral changes using a dual-energy CT (DECT) (based on Choi's criteria) and to compare it to traditional Response Evaluation Criteria in Solid Tumors (RECIST) criteria., Materials and Methods: Ten NSCLC patients treated with bevacizumab underwent DECT. Tumor responses to anti-angiogenic therapy were assessed and compared with the baseline CT results using both RECIST (size changes only) and Choi's criteria (reflecting net tumor enhancement). Kappa statistics was used to evaluate agreements between tumor responses assessed by RECIST and Choi's criteria., Results: The weighted κ value for the comparison of tumor responses between the RECIST and Choi's criteria was 0.72. Of 31 target lesions (21 solid nodules, 8 lymph nodes, and two ground-glass opacity nodules [GGNs]), five lesions (16%) showed discordant responses between RECIST and Choi's criteria. Iodine-enhanced images allowed for a distinction between tumor enhancement and hemorrhagic response (detected in 14% [4 of 29, excluding GGNs] of target lesions on virtual nonenhanced images)., Conclusion: DECT may serve as a useful tool for response evaluation after anti-angiogenic treatment in NSCLC patients by providing information on the net enhancement of target lesions without obtaining non-enhanced images.

Objective: We retrospectively analyzed the CT features of late-onset noninfectious pulmonary complications in patients with pathologically proven graft-versus-host disease (GVHD) after allogeneic stem cell transplant (SCT)., Materials and Methods: We analyzed the CT features of late-onset noninfectious pulmonary complications in 14 patients with pathologic diagnoses of GVHD who survived disease free for more than 3 months after SCT. Late-onset noninfectious pulmonary complications were diagnosed by excluding pulmonary infection in these patients with respiratory symptoms and signs. The presence, extent, and distribution of CT features were evaluated in terms of geographic hypoattenuation, expiratory airtrapping, ground-glass attenuation (GGA), reticulation, crazy paving pattern, bronchiectasis, nodules, and honeycombing. Further disease classification was made on the basis of clinical, radiologic, and pulmonary function test results and histologic findings. The longitudinal changes of late-onset noninfectious pulmonary complications were followed with CT., Results: The 14 patients with late-onset noninfectious pulmonary complications were classified into subgroups with bronchiolitis obliterans (BO) (n = 7), nonclassifiable interstitial pneumonia (n = 5), and combined BO and nonclassifiable interstitial pneumonia (n = 2). The CT features of nonclassifiable interstitial pneumonia were GGA (5/7, 71%), reticulation (4/7, 57%), and crazy paving pattern (4/7, 57%) with a peribronchovascular distribution (6/7, 86%). All patients with nonclassifiable interstitial pneumonia had progression of disease with an increased extent of traction bronchiectasis, reticulation, and honeycombing on follow-up CT scans (median follow-up period, 22 months)., Conclusion: Although not commonly encountered, nonclassifiable interstitial pneumonia as a pattern of chronic GVHD should be included in the differential diagnosis of unexplained peribronchial GGA or progressive traction bronchiectasis after SCT.

Peroxisome proliferator-activated receptor-γ (PPARγ) agonists exhibit potent anti-fibrotic effects in the lung and other tissues. Recently, micro-computed tomography (CT) has been a useful tool for the investigation of lung diseases in small animals and is now increasingly applied to visualize and quantify the pulmonary structures. However, there is little information on the assessment for therapeutic effects of PPARγ agonists on the pulmonary fibrosis in mice using micro-CT. This study was aimed to determine the capability of micro-CT in examining the effects of rosiglitazone on pulmonary fibrosis. We used a murine model of bleomycin-induced lung fibrosis to evaluate the feasibility of micro-CT in evaluating the therapeutic potential of rosiglitazone on pulmonary fibrosis, comparing with pathologic scores. On micro-CT findings, ground glass opacity (80%) and consolidation (20%) were observed predominantly at 3 weeks after the instillation of bleomycin, and the radiologic features became more complex at 6 weeks. In bleomycin-instilled mice treated with rosiglitazone, the majority (80%) showed normal lung features on micro-CT. Radiological-pathologic correlation analyses revealed that ground glass opacity and consolidation were correlated closely with acute inflammation, while reticular opacity was well correlated with histological honeycomb appearance. These results demonstrate that rosiglitazone displays a protective effect on pulmonary fibrosis in mice and that the visualization of bleomycin-induced pulmonary fibrosis using micro-CT is satisfactory to assess the effects of rosiglitazone. It implies that micro-CT can be applied to evaluate therapeutic efficacies of a variety of candidate drugs for lung diseases., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Objectives: To determine the positive reading criteria for malignant nodes when interpreting combined MRI and PET/CT images for preoperative nodal staging in non-small-cell lung cancer (NSCLC)., Methods: Forty-nine patients with biopsy-proven NSCLC underwent both PET/CT and thoracic MRI [diffusion weighted imaging (DWI)]. Each nodal station was evaluated for the presence of metastasis by applying either inclusive (positive if either one read positive) or exclusive (positive if both read positive) criteria in the combined interpretation of PET/CT and MRI. Nodal stage was confirmed pathologically. The combined diagnostic accuracy of PET/CT and MRI was determined on per-nodal station and per-patient bases and compared with that of PET/CT alone., Results: In 49 patients, 39 (19%) of 206 nodal stations harboured malignant cells. Out of 206 nodal stations, 186 (90%) had concordant readings, while the rest (10%) had discordant readings. Inclusive criteria of combined PET/CT and MRI helped increase sensitivity for detecting nodal metastasis (69%) compared with PET/CT alone (46%; P = 0.003), while specificity was not significantly decreased., Conclusion: Inclusive criteria in combined MRI and PET/CT readings help improve significantly the sensitivity for detecting nodal metastasis compared with PET/CT alone and may decrease unnecessary open thoracotomy. Key Points • Combined interpretation of MRI and PET/CT enhances the detection of nodal metastasis. • Inclusive criteria of combined MRI/PET/CT improved the sensitivity for detecting nodal metastasis. • Combined interpretation of MRI and PET/CT may reduce unnecessary open thoracotomies.

Objective: We investigated low dose digital tomosynthesis (DT) for the evaluation of the paranasal sinus (PNS), and compared its diagnostic accuracy with a PNS radiography series (XR)., Materials and Methods: We enrolled 43 patients for whom XR, PNS DT, and OMU CT were performed. We measured effective doses (EDs) of XR, DT, and OMU CT using Monte Carlo simulation software. Two radiologists performed independent observation of both XR and DT. For seven PNSs, they scored anatomic conspicuity of sinuses and confidence on the presence of sinusitis using nine point scales. OMU CT was observed by the third radiologist and the findings were regarded as reference standard. We compared scores for conspicuity and sinusitis confidence between XR and DT., Results: Mean EDs were 29 ± 6 µSv, 48 ± 10 µSv, and 980 ± 250 µSv, respectively, for XR, DT, and CT. Mean scores for conspicuity were 6.3 and 7.4, respectively, for XR and DT. Sensitivity per patient basis for sinusitis detection were 52% and 96%, respectively, for XR and DT in observer 1 (p = 0.001) and 80% and 92% for observer 2 (p = 0.25). Specificities for sinusitis exclusion were 100% for both XR and DT for observer 1 and 89% and 100% for observer 2 (p = 0.50). Accuracies for sinusitis diagnosis were 72% and 98%, respectively, for XR and DT for observer 1 (p = 0.001) and 84% and 95% for observer 2 (p = 0.125)., Conclusion: Patient radiation dose from low dose DT is comparable with that of PNS XR. Diagnostic sensitivity of DT for sinusitis was superior to PNS XR.

Purpose: To assess the correlation among quantitative indexes of computed tomography (CT), spirometric pulmonary function tests (PFTs), and visual scores (VSs) of CT in patients with diffuse interstitial lung disease (DILD) and to prove the estimated value of CT quantification for the prediction of the possibility of pulmonary function impairment., Methods and Materials: A total of 157 patients (male to female ratio, 96:61; mean age, 63 ± 11 years) with DILD were enrolled in this study. All patients underwent volume thin-section CT in the supine position at full inspiration. During the same period, 23 people (male to female ratio, 10:13; mean age, 55 ± 13 years) with no history of DILD and with normal PFTs and CT findings were used as a control group. Quantitative indexes were obtained using a commercial CAD system (Brilliance Workspace v3.0; Philips Medical Systems). Quantitative indexes included total lung volume (TLV), mean lung attenuation, variation of lung attenuation, emphysema volume (<-950 Hounsfield units [HU]), functioning lung volume (-700 HU > pixel > -950 HU), and interstitial lung disease volume (>-700 HU). Visual scores were measured semiquantitatively and included the overall extent of pulmonary parenchymal abnormality as well as the extent of consolidation, ground glass opacity, reticulation, and honeycomb opacities. Quantitative indexes were correlated with PFT and VSs using the Pearson correlation test., Results: Quantitative indexes, PFT results, and VSs differed significantly between the DILD group and the control group, except for emphysematous parameters (P < 0.05).Pulmonary function test results showed significant correlation with quantitative indexes in the DILD group. Functioning lung volume showed positive correlation with forced vital capacity and forced expiratory volume in 1 second (r = 0.80 and 0.73, P < 0.001). Total lung capacity showed positive correlation with TLV (r = 0.83, P < 0.001).Visual scores were correlated with the ratio of a specific volume to TLV (indicated as ®). Interstitial lung disease volume® showed positive correlation (r = 0.53, P < 0.001), and FLV® showed a negative correlation with the overall extent of ILD (r = -0.52, P < 0.001). variation of lung attenuation showed a positive correlation with honeycombing extent (r = 0.37, P < 0.001), and mean lung attenuation showed a positive correlation with reticulation extent (r = 0.42, P < 0.001)., Conclusions: Quantitative indexes measured by a commercial workstation showed good correlation not only with the extent of DILD estimated by visual inspection but also with PFT results. Quantitative indexes can be used as an objective tool for quantitative evaluation of disease extent and for follow-up of the progression or improvement of a DILD.

Objective: We wanted to evaluate the usefulness of the computer-aided detection (CAD) system for detecting pulmonary nodules in real clinical practice by using the CT images., Materials and Methods: Our Institutional Review Board approved our retrospective study with a waiver of informed consent. This study included 166 CT examinations that were performed for the evaluation of pulmonary metastasis in 166 patients with colorectal cancer. All the CT examinations were interpreted by radiologists and they were also evaluated by the CAD system. All the nodules detected by the CAD system were evaluated with regard to whether or not they were true nodules, and they were classified into micronodules (MN, diameter < 4 mm) and significant nodules (SN, 4 ≤ diameter ≤ 10 mm). The radiologic reports and CAD results were compared., Results: The CAD system helped detect 426 nodules; 115 (27%) of the 426 nodules were classified as true nodules and 35 (30%) of the 115 nodules were SNs, and 83 (72%) of the 115 were not mentioned in the radiologists' reports and three (4%) of the 83 nodules were non-calcified SNs. One of three non-calcified SNs was confirmed as a metastatic nodule. According to the radiologists' reports, 60 true nodules were detected, and 28 of the 60 were not detected by the CAD system., Conclusion: Although the CAD system missed many SNs that are detected by radiologists, it helps detect additional nodules that are missed by the radiologists in real clinical practice. Therefore, the CAD system can be useful to support a radiologist's detection performance.

Objective: We wanted to compare the efficacy of the new CT response evaluation criteria for predicting the tumor progression-free survival (PFS) with that of RECIST 1.1 in non-small cell lung cancer (NSCLC) patients who were treated with bevacizumab., Materials and Methods: Sixteen patients (M:F = 11:5; median age, 57 years) treated with bevacizumab and combined cytotoxic chemotherapeutic agents were selected for a retrospective analysis. The tumor response was assessed by four different methods, namely, by using RECIST 1.1 (RECIST), RECIST but measuring only the solid component of tumor (RECISTsolid), the alternative method reflecting tumor cavitation (the alternative method) and the combined criteria (the combined criteria) that evaluated both the changes of tumor size and attenuation. To evaluate the capabilities of the different measurement methods to predict the patient prognosis, the PFS were compared, using the log rank test, among the responder groups (complete response [CR], partial response [PR], stable disease [SD] and progressive disease [PD]) in terms of the four different methods., Results: The overall (CR, PR or SD) response rates according to RECIST, RECISTsolid, the alternative method and the combined criteria were 81%, 88%, 81% and 85%, respectively. The confirmed response rates (CR or PR) were 19%, 19%, 50% and 54%, respectively. Although statistically not significant, the alternative method showed the biggest difference for predicting PFS among the three response groups (PR, SD and PD) (p = 0.07). RECIST and the alternative method showed a significant difference for predicting the prognosis between the good (PR or SD) and poor overall responders (p = 0.02)., Conclusion: The response outcome evaluations using the three different CT response criteria that reflect tumor cavitation, the ground-glass opacity component and the attenuation changes in NSCLC patients treated with bevacizumab showed different results from that with using the traditional RECIST method.

Objective: We conducted a review of serial high-resolution CT (HRCT) findings of cryptogenic organizing pneumonia (COP)., Materials and Methods: Over the course of 14 years, we saw 32 patients with biopsy-confirmed COP. Serial HRCT scans were available for only 22 patients (seven men and 15 women; mean age, 52 years; median follow-up period, 8 months; range, 5-135 months). Serial CT scans were evaluated by two chest radiologists who reached a conclusion by consensus. Overall changes in disease extent were classified as cured, improved (i.e., ≥ 10% decrease in extent), not changed, or progressed (i.e., ≥ 10% increase in extent). When there were remaining abnormalities, the final follow-up CT images were analyzed to express observers' ideas regarding what type of interstitial lung disease the images most likely suggested., Results: The two most common patterns of lung abnormality on initial scans were ground-glass opacification (86% of patients [19/22]) and consolidation (77% of patients [17/22]), distributed along the bronchovascular bundles or subpleural lungs in 13 patients (59%). In six patients (27%), the disease disappeared completely; in 15 patients (68%), the disease was decreased in extent; and in one patient (5%), no change in extent was detected on follow-up CT. When lesions remained, the final follow-up CT findings were reminiscent of fibrotic nonspecific interstitial pneumonia in 10 of 16 patients (63%)., Conclusion: Although COP is a disease with a generally good prognosis, most patients (73%) with COP have some remaining disease seen on follow-up CT scans, and, in such cases, the lesions generally resemble a fibrotic nonspecific interstitial pneumonia pattern.

Background: To evaluate the importance of assessing volume-based parameter of (18)F-FDG PET/CT in patients with malignant pleural mesothelioma (MPM) for the prediction of response and patient outcome early in the course of treatment., Materials and Methods: Patients (n = 13; M:F = 9:4, mean age, 54 years) with histopathologically proven MPM, all of whom were scheduled to undergo curative extrapleural pneumonectomy (EPP) or palliative chemotherapy, were included in this study. They were evaluated using integrated (18)F-FDG PET/CT at baseline. Maximum standardized uptake value (SUVmax), average SUV (SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured using PET/CT data. Relationships between tumor progression and PET parameters were statistically analyzed., Results: Of the 13 patients, 8 (62%) developed disease recurrence after surgery or tumor progression after chemotherapy (median follow-up, 329 days; range, 28-536 days). Between subgroups with and without tumor progression, significant differences were noted in MTV (P = 0.045). On ROC curve analysis, MTV (AUC = 0.850, 95% confidence interval [95% CI] 0.550-0.977) and TLG (AUC = 0.800, 95% CI 0.494-0.960) showed good predictive performance for tumor progression. Multivariate analysis adjusted for treatment modality showed that MTV (HR 1.003, P = 0.025) and TLG (HR 1.001, P = 0.031) were independent factors associated with tumor progression. Time to tumor progression was shorter in patients with a high volume-based parameter of PET than in those with a low value., Conclusions: Volume-based parameters of (18)F-FDG PET/CT have the potential to provide prognostic information in MPM patients who are receiving surgery or palliative chemotherapy.

Background: The purpose of this study was to identify the CT scan features that predict patient outcome after reexpansion procedures in patients with the fibrotic stage of endobronchial TB., Methods: We retrospectively enrolled 30 patients (four men, 26 women) aged 32 +/- 11 years who had lobar or whole-lung atelectasis as sequela of endobronchial TB. Patients underwent helical CT scan examinations and subsequent reexpansion procedures for atelectasis, including balloon dilatation (n = 2), stent placement (n = 23), and surgical bronchoplasty (n = 5). Two thoracic radiologists evaluated the location and extent of airway narrowing, the extent of volume loss, parenchymal calcification, mucus plugging, and bronchiectasis within atelectasis on preprocedural CT scans. The success of reexpansion procedures was defined as the recovery of lung volume being > 80% of the estimated original volume as determined during follow-up imaging. Preprocedural CT scans and clinical features were compared for the results of the reexpansion procedures using the Wilcoxon two-sample test or Fisher exact test., Results: Atelectasis was reexpanded in 30% (nine of 30) of patients after reexpansion procedures. The presence of parenchymal calcification and bronchiectasis within atelectasis showed a high tendency of failure in reexpansion procedures (P < .001). Mucus plugging, the extent of airway narrowing, volume loss on CT images, and endobronchial TB activity at the time of intervention did not affect the results (P > .05). Patients with successful results were significantly younger than those with unsatisfactory results., Conclusions: Parenchymal calcification and bronchiectasis within atelectasis are correlated with a high chance of failure in reexpansion procedures. Knowledge of CT scan features may help radiologists to predict the results of lung-conserving therapy to avoid unnecessary interventions.

Objective: To evaluate the relationship between a computed tomographic reconstruction kernel and the sensitivity of a computer-aided detection (CAD) system for lung nodule detection., Methods: We retrospectively studied 36 consecutive patients with no known pulmonary nodules who underwent low-dose computed tomography for lung cancer screening with 3 different reconstruction kernels (B, C, and L). All series were reviewed with a commercial CAD system for lung nodule detection., Results: The 36 scans showed 231 uncalcified nodules (170 micronodules and 61 nodules). There was little variation of sensitivities for each series (82%, 88%, and 82% for the nodules of B, C, and L, respectively). When the results of 2 series were combined, sensitivities were boosted (B + C, 89%; B + L, 95%; and C + L, 96% for the nodules)., Conclusions: Sensitivity of the CAD system was influenced by the selection of the reconstruction kernel. By combining data from 2 different kernels, CAD sensitivity can be elevated without further patient radiation exposure.

We aimed to evaluate prospectively the efficacy of positron emission tomography (PET)/computed tomography (CT) plus brain magnetic resonance imaging (MRI) for detecting extrathoracic metastases in lung adenocarcinoma. Metastatic evaluations were feasible for 442 consecutive patients (M:F=238:204; mean age, 54 yr) with a lung adenocarcinoma who underwent PET/CT (CT, without IV contrast medium injection) plus contrast-enhanced brain MRI. The presence of metastases in the brain was evaluated by assessing brain MRI or PET/CT, and in other organs by PET/CT. Diagnostic efficacies for metastasis detection with PET/CT plus brain MRI and with PET/CT only were calculated on a per-patient basis and compared from each other. Of 442 patients, 88 (20%, including 50 [11.3%] with brain metastasis) had metastasis. Regarding sensitivity of overall extrathoracic metastasis detection, a significant difference was found between PET/CT and PET/CT plus brain MRI (68% vs. 84%; P=0.03). As for brain metastasis detection sensitivity, brain MRI was significantly higher than PET/CT (88% vs. 24%; P<0.001). By adding MRI to PET/CT, brain metastases were detected in additional 32 (7% of 442 patients) patients. In lung adenocarcinoma patients, significant increase in sensitivity can be achieved for detecting extrathoracic metastases by adding dedicated brain MRI to PET/CT and thus enhancing brain metastasis detection.

Objective: The purpose of this article is to correlate MRI findings of mediastinal nodes with PET/CT and pathology in non-small cell lung cancer., Conclusion: Malignant nodes show high FDG uptake at PET, or eccentric cortical thickening or obliterated fatty hilum on T2-weighted MRI. Benign nodes (with follicular hyperplasia, sinus histiocytosis, fibrotic micronodules, or calcification) may show high FDG uptake at PET, whereas MRI may help distinguish benign from malignant nodes by showing low signal intensity in nodes on T2-weighted MRI.

Clear cell tumor of the lung is a rare and very unusual benign pulmonary tumor. As clear cell tumor of the lung contains abundant cytoplasmic glycogen, this tumor is called "sugar tumor". We report a case of sugar tumor in a 64-yr-old man presenting as a round pulmonary nodule. On dynamic computed tomography (CT) scans, the solitary pulmonary nodule showed early wash-in enhancement with an early washout pattern like a lung malignancy. The patient underwent wedge resection for the tumor. Pathologic examination, including immunohistochemical studies, revealed that the nodule was a benign clear cell tumor, so-called "sugar tumor". Because only a small number of cases have been reported previously, clinical aspects, radiological characteristics on dynamic contrast-enhanced CT, and differential diagnosis of the tumor are not well established. Herein we present a clear cell tumor of the lung and discuss the clinical, radiological, and pathological features of the tumor.

Objective: To determine if a ThinPrep processor (Cytyc Corporation, Boxborough, Massachusetts, U.S.A.) could be used to improve diagnostic accuracy in the absence of a cytopathologist at the time of computed tomography-guided (CT-guided) transthoracic needle aspiration biopsy (TNAB) of the lung., Study Design: Ninety-two patients (59 men and 33 women who were 26-85 years old) underwent CT-guided TNAB. The aspirated specimen was prepared with the ThinPrep cytopreparatory technique for cytologic evaluation. The final histologic diagnoses were based on the pathologic material obtained from a cutting needle biopsy, bronchoscopic biopsy and surgical excision and the on clinical follow-up (mean, 12 months). On this basis, the accuracy, sensitivity and specificity of TNAB for malignant lesions were calculated by comparing the diagnoses obtained from percutaneous transthoracic needle aspiration with the final diagnoses using a chi2 test. was made, 56 (60.9%) were malignant and 36 (39.1%) benign. The diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value for the diagnosis of malignancy were 92%, 87.5%, 100%, 100% and 80%, respectively., Conclusion: CT-guided TNAB using ThinPrep provided excellent diagnostic accuracy and was useful because this technique shows less air-drying artifact and can separate cells and blood clots on the slides.

Purpose: To compare prospectively the diagnostic efficacies of integrated positron emission tomography (PET)/computed tomography (CT) and 3.0-T whole-body magnetic resonance (MR) imaging for determining TNM stages in non-small cell lung cancer (NSCLC)., Materials and Methods: Institutional review board approval and informed consent were obtained. The study included 165 patients (125 men, 40 women; mean age, 61 years) with NSCLC proved at pathologic examination who underwent both unenhanced PET/CT and whole-body MR imaging. Pathologic findings for T (n = 123) and N (n = 150) staging and pathologic or follow-up imaging findings (n = 154) for M staging were reference standards. The efficacies of PET/CT and whole-body MR imaging for lung cancer staging were compared by using the McNemar test., Results: Primary tumors (n = 123 patients) were correctly staged in 101 (82%) patients at PET/CT and in 106 (86%) patients at whole-body MR imaging (P = .263). N stages (n = 150 patients) were correctly determined in 105 (70%) patients at PET/CT and in 102 (68%) patients at whole-body MR imaging (P = .880). Thirty-one (20%) of 154 patients had metastatic lesions. Accuracy for detecting metastases was 86% (133 of 154 patients) at PET/CT, and that at whole-body MR imaging was 86% (132 of 154 patients) (P > .99). Although the differences were not statistically significant, whole-body MR imaging was more useful for detecting brain and hepatic metastases, whereas PET/CT was more useful for detecting lymph node and soft-tissue metastases., Conclusion: Both PET/CT and 3.0-T whole-body MR imaging appear to provide acceptable accuracy and comparable efficacy for NSCLC staging, but for M-stage determination, each modality has its own advantages.

Objective: The purpose of our study was to show the usefulness of nongated low-dose chest CT for coronary screening by comparing the results of coronary artery calcium measurement with that of dedicated calcium-scoring CT., Materials and Methods: One hundred twenty-eight consecutive participants (all men; mean age, 52 +/- 7 years) underwent low-dose chest CT and calcium-scoring CT with prospective ECG gating using 40-MDCT. Low-dose chest CT volume data were reconstructed as 25-cm field of view and three slice thicknesses: 1, 2.5, and 5 mm. For each examination, the lesion area, Agatston calcium score, and calcium mass were measured at 90- and 130-H thresholds. All measurements (130-H threshold) from the calcium-scoring CT were used as reference standards. Spearman's correlation test was used to compare the results., Results: Among the low-dose chest CT examinations, sensitivity was best determined with a 1-mm slice thickness at 130 H and 2.5-mm slice thickness at 90 H. Specificity was best determined with a 5-mm slice thickness at 130 H. Accuracy (90%) was best determined with a 2.5-mm slice thickness at 130 H. Of all protocols, calcium area, score, and mass from a 2.5-mm slice thickness at 130 H correlated best with the reference results (r = 0.89 for all three criteria)., Conclusion: Using a low radiation dose and nongated MDCT, we can detect coronary artery calcium and obtain results comparable to those obtained with dedicated calcium-scoring CT that uses a higher dose and ECG gating.

Objective: To evaluate the relationship between CT dose and the performance of a computer-aided diagnosis (CAD) system, and to determine how best to minimize patient exposure to ionizing radiation while maintaining sufficient image quality for automated lung nodule detection, by the use of lung cancer screening CT., Materials and Methods: Twenty-five asymptomatic volunteers participated in the study. Each volunteer underwent a low-dose CT scan without contrast enhancement (multidetector CT with 16 detector rows, 1.25 mm section thickness, 120 kVp, beam pitch 1.35, 0.6 second rotation time, with 1.25 mm thickness reconstruction at 1.25 mm intervals) using four different amperages 32, 16, 8, and 4 mAs. All series were analyzed using a commercially available CAD system for automatic lung nodule detection and the results were reviewed by a consensus reading by two radiologists. The McNemar test and Kappa analysis were used to compare differences in terms of the abilities to detect pulmonary nodules., Results: A total of 78 non-calcified true nodules were visualized in the 25 study subjects. The sensitivities for nodule detection were as follows: 72% at 32 mAs, 64% at 16 mAs, 59% at 8 mAs, and 40% at 4 mAs. Although the overall nodule-detecting performance was best at 32 mAs, no significant difference in nodule detectability was observed between scans at 16 mAs or 8 mAs versus 32 mAs. However, scans performed at 4 mAs were significantly inferior to those performed at 32 mAs (p < 0.001)., Conclusion: Reducing the radiation dose (i.e. reducing the amperage) lowers lung nodule detectability by CAD. However, relatively low dose scans were found to be acceptable and to cause no significant reduction in nodule detectability versus usual low-dose CT.

Background: Few articles have been published on imaging findings of marginal zone B-cell lymphoma of bronchus-associated lymphoid tissue (BALT) of the lung. We present CT scan and 18F-fluorodeoxyglucose (FDG) PET scan findings of the disease., Methods: From March 1995 to February 2007, 21 pretreatment patients (male patients, 9; female patients, 12; age range, 35 to 76 years; mean [+/- SD] age, 54 +/- 10.4 years) were seen who had pathologic diagnoses of marginal zone B-cell lymphoma of BALT. After CT scans were reviewed searching for specific patterns and distribution of parenchymal lung lesions, patients were classified as having the following four different patterns: (1) single nodular or consolidative; (2) multiple nodular or areas of consolidation; (3) bronchiectasis and bronchiolitis; and (4) diffuse interstitial lung disease (DILD) patterns. In six patients, in whom PET/CT scanning was performed, the pattern and the extent of maximum standardized uptake values (mSUVs) of FDG uptake were described., Results: A single nodular or consolidative pattern was observed in 7 of 21 (33%) patients, multiple nodular or areas of consolidation were observed in 9 patients (43%), bronchiectasis and bronchiolitis were observed in 3 patients (14%), and DILD was observed in 2 patients (10%). On PET scans (n = 6), lesions showed heterogeneous FDG uptake in five patients and homogeneous uptake in one patient, with mSUVs ranging from 2.2 to 6.3 (mean mSUV, 4.2 +/- 1.48)., Conclusions: Marginal zone B-cell lymphomas of BALT manifest diverse patterns of lung abnormality on CT scans, but single or multiple nodules or areas of consolidation are the main patterns that occur in a majority (76%) of patients. Most lesions show heterogeneous but identifiable FDG uptake on PET scans.

Objective: The aim of this study was to assess the diagnostic efficacy of integrated PET/CT using fluorodeoxyglucose (FDG) for the differentiation of benign and metastatic adrenal gland lesions in patients with lung cancer and to compare the diagnostic efficacy with the use of PET alone., Materials and Methods: Sixty-one adrenal lesions (size range, 5-104 mm; mean size, 16 mm) were evaluated retrospectively in 42 lung cancer patients. Both PET images alone and integrated PET/CT images were assessed, respectively, at two-month intervals. PET findings were interpreted as positive if the FDG uptake of adrenal lesions was greater than or equal to that of the liver, and the PET/CT findings were interpreted as positive if an adrenal lesion show attenuation > 10 HU and showed increased FDG uptake. Final diagnoses of adrenal gland lesions were made at clinical follow-up (n = 52) or by a biopsy (n = 9) when available. The diagnostic accuracies of PET and PET/CT for the characterization of adrenal lesions were compared using the McNemar test., Results: Thirty-five (57%) of the 61 adrenal lesions were metastatic and the remaining 26 lesions were benign. For the depiction of adrenal gland metastasis, the sensitivity, specificity, and accuracy of PET were 74%, 73%, and 74%, respectively, whereas those of integrated PET/CT were 80%, 89%, and 84%, respectively (p values; 0.5, 0.125, and 0.031, respectively)., Conclusion: The use of integrated PET/CT is more accurate than the use of PET alone for differentiating benign and metastatic adrenal gland lesions in lung cancer patients.

We tried to assess retrospectively thin-section CT findings of Churg-Strauss syndrome (CSS) in 25 patients and to compare these findings with clinical and histopathologic findings. Of 25 patients, 19 (76%) had parenchymal abnormalities at CT; small nodules (n = 12; 63%), ground-glass opacity (n = 10; 53%), bronchial wall thickening (n = 10; 53%), and consolidation (n = 8; 42%). Parenchymal abnormalities (n = 19) were categorizable as an airway pattern in 11 and an airspace pattern in eight. Patients with an airway pattern (n = 5) had obstructive (n = 3) or combined (n = 2) PFT results, whereas those with an airspace pattern (n = 4) had restrictive (n = 3) or obstructive (n = 1) results. Parenchymal opacities at CT corresponded histologically to areas of eosinophilic pneumonia, necrotizing granulomas, and granulomatous vasculitis; small nodules to eosinophilic bronchiolitis and peribronchiolar vasculitis; and bronchial wall thickening to airway wall eosinophil and lymphocyte infiltration. Patients with airspace pattern responded more readily to treatment than those with airway pattern. CT shows lung parenchymal abnormalities in about three-quarters of CSS patients and these abnormalities can be categorized as airspace or airway patterns. This classification helps predict PFT data, underlying histopathology, and treatment response.

Objective: To document the computed tomographic (CT) image features of gastric and hepatic complications after ingestion of glacial acetic acid., Materials and Methods: There were 5 patients (2 men and 3 women; age range, 2-84 years) who had ingested glacial acetic acid to commit suicide or accidentally. Their abdominal and chest CT scans were retrospectively reviewed to detect and evaluate visceral organ injury. Clinical and laboratory data were also reviewed., Results: Diffuse edematous wall thickening of esophagus and stomach was observed in all patients. Three patients showed nonenhancing, wedge-shaped low densities in the liver on portal venous phase abdominal CT scans. These 3 patients also showed laboratory findings to indicate hepatic failure, hemolysis, metabolic acidosis, and disseminated intravascular coagulation. Two of these patients died despite vigorous supportive treatment., Conclusions: Wedge-shaped low densities can be seen in the liver on CT scans after ingestion of glacial acetic acid. They may represent hepatic necrosis caused by the direct effect of toxic materials absorbed into portal circulation.

This study was conducted to observe effects of two methods of setting positive end-expiratory pressure (PEEP) based on the pressure-volume (PV) curve. After lung injury was induced by oleic acid in six mongrel adult dogs, the inflation PV curve was traced and the lower inflection point (LIP) was measured. The 'PEEP(INF)' was defined as LIP+2 cmH(2)O. After recruitment maneuver to move the lung physiology to the deflation limb of PV curve, decremental PEEP was applied. The lowest level of PEEP that did not result in a significant drop in PaO(2) was defined as the 'PEEP(DEF)'. Arterial blood gases, lung mechanics, hemodynamics, and lung volumes (measured on computed tomography during end-expiratory pause) were measured at PEEP of 0 cmH(2)O, PEEP(INF) and PEEP(DEF) sequentially. The median PEEP(INF) was 13.4 cm H(2)O (interquartile range, 12.5-14.3) and median PEEP(DEF) was 12.0 cm H(2)O (10.0-16.5) (p=0.813). PEEP(DEF) was associated with significantly higher PaO(2) and lung volumes, and significantly lower shunt fraction and cardiac index when compared to PEEP(INF) (p<0.05). Setting the PEEP based on the deflation limb of the PV curve was useful in improving oxygenation and lung volumes in a canine lung injury model.

Objective: The purpose of this study was to describe retrospectively integrated PET/CT findings on pulmonary neuroendocrine tumors and to correlate the findings with prognosis., Materials and Methods: Between May 2003 and February 2005, 37 consecutively enrolled patients (33 men and four women; mean age, 60 years) with histopathologically proven pulmonary neuroendocrine tumors underwent 18F-FDG PET/CT after enhanced standalone CT. CT was used to analyze the morphologic features of the tumors and PET to measure maximum standardized uptake value (SUV). Maximum SUVs of carcinoid tumors, large-cell neuroendocrine carcinomas (LCNECs), and small-cell lung carcinomas (SCLCs) were compared, and maximum SUV and tumor stage and prognosis were correlated., Results: Four (two typical and two atypical) of the seven carcinoid tumors had no FDG uptake or less than mediastinal uptake. The maximum SUVs of primary tumors, in increasing order, were significantly different for carcinoids (mean, 4.0; median, 3.4), LCNECs (mean, 12.0; median, 10.7), and SCLCs (mean, 11.6; median, 11.7) (p = 0.006, Kruskal-Wallis test). There was no significant correlation between maximum SUV of the primary tumor and the tumor stages of carcinoids, LCNECs, or SCLCs (p = 0.08, Jonckheere-Terpstra test; p = 0.768, Mann-Whitney test). Results of receiver operating characteristics analysis showed a maximum SUV greater than 13.7 suggested a poor survival period in cases of LCNEC and SCLC., Conclusion: The maximum SUVs of neuroendocrine tumors are significantly different for carcinoid tumors, LCNECs, and SCLCs, and a high maximum SUV suggests short survival of patients with LCNEC or SCLC.

Integrated fluorine-18 fluorodeoxyglucose positron emission tomography (PET)-computed tomography (CT) for adrenal gland imaging in cancer patients allows early detection and accurate localization of adrenal lesions and differentiation of metastatic nodules from benign lesions, thereby facilitating treatment planning. However, false-positive findings are encountered at integrated PET-CT in approximately 5% of adrenal lesions identified as positive at PET, including adrenal adenomas, adrenal endothelial cysts, and inflammatory and infectious lesions. Moreover, false-negative findings may be seen in adrenal metastatic lesions with hemorrhage or necrosis, small-sized (<10-mm) metastatic nodules, and metastases from pulmonary bronchioloalveolar carcinoma or carcinoid tumors. An awareness of the potential pitfalls of integrated PET-CT enhances the diagnostic efficacy of this modality by allowing differentiation of metastatic adrenal lesions from other abnormalities., (RSNA, 2006)

Histoplasmosis is the most common endemic mycosis in North America, and is followed by coccidioidomycosis and blastomycosis. Although the majority of these infections in immunocompetent persons are self-limited, some patients can develop severe pneumonitis or various forms of chronic pulmonary infection. Cryptococcoci, Aspergillus, Candidas, and Mucorals are ubiquitous organisms, which may affect immunocompromised patients. Specific imaging findings can be expected, depending on the organisms involved, underlying patients' conditions (immune status), and specific situations after immune depleting procedures.

Objective: The purpose of this study was to describe the dynamic CT findings of pulmonary sclerosing hemangioma presenting as a solitary pulmonary nodule and to compare these findings with histopathologic findings., Conclusion: On dynamic CT, sclerosing hemangioma has strong and rapid enhancement attributed histopathologically to the presence of hemangiomatous or papillary components in the tumor.

Objective: The purpose of this study was to describe the radiographic and high-resolution CT (HRCT) findings of adenovirus pneumonia in five patients., Conclusion: Adenovirus pneumonia in adults appears as bilateral patchy parenchymal opacities on chest radiographs and as bilateral ground-glass opacities with a random distribution with or without consolidation on HRCT images. These findings, however, are not specific for adenovirus pneumonia.

Objective: We aimed to identify CT enhancement characteristics that predict hilar or mediastinal nodal metastasis in patients with stage T1 lung cancer., Subjects and Methods: Eighty-four patients (50 men and 34 women; age range, 39-80 years; mean age, 61 years) with stage T1 lung cancer underwent a hemodynamic and a conventional morphologic CT study before curative surgical resection. Peak enhancement (maximum attenuation over the entire time course), net enhancement (peak enhancement minus preenhancement attenuation), maximum enhancement ratio (MER), time to peak enhancement, slope of enhancement on dynamic studies, nodule size, presence of tumor necrosis or thickening of bronchovascular bundles, and marginal characteristics on morphologic studies were analyzed and correlated with the presence of histologically determined mediastinal or hilar nodal metastasis., Results: Mediastinal or hilar nodal metastases were found at surgery in 26 (31%) of 84 patients: mediastinal nodes in 13 (15%) and hilar nodes in 19 (23%). Six (7%) had both mediastinal and hilar nodal metastasis. Peak enhancement, net enhancement, and MER were significantly associated (p = 0.001, 0.002, and 0.008, respectively) with the presence of mediastinal or hilar nodal metastasis. A peak attenuation of 110 H or greater and a net enhancement of 60 H or greater predicted nodal metastasis with accuracies of 73% (61/84 nodules) and 73% (61/84 nodules) and odd ratios of 4.98 and 5.94, respectively., Conclusion: Stage T1 lung cancers showing peak enhancement of 110 H or greater or net enhancement of 60 H or greater on dynamic CT indicate a high likelihood of hilar or mediastinal nodal metastasis.

Objective: In this pictorial essay, we show the usefulness of MDCT angiography for visualization of the bronchial and nonbronchial systemic feeder vessels responsible for hemoptysis., Conclusion: By providing thin-section transaxial, multiplanar reconstruction, and 3D images, CT angiography using MDCT allows comparable or better images than conventional angiography with respect to the depiction of bronchial or nonbronchial systemic arteries. CT angiography is particularly useful for visualizing the ectopic origin of bronchial arteries and nonbronchial systemic collateral arteries.

Objective: We describe a number of benign focal lung lesions with increased 18F-FDG uptake that simulate lung cancer and malignant lesions that lead to false-negatives due to little 18F-FDG uptake on integrated PET/CT images., Conclusion: The integration of clinical history, morphologic findings of lung parenchymal lesions on the CT component, and metabolic activities on the PET component of integrated PET/CT can help reduce false interpretation of the study. A lung biopsy may be needed for lesions showing increased 18F-FDG uptake on PET for tissue confirmation irrespective of their morphology on CT.