Outcomes and prognosis of progressive pulmonary fibrosis in patients with antineutrophil cytoplasmic antibody-positive interstitial lung disease.

Approximately one-third of fibrosing interstitial lung diseases exhibit progressive pulmonary fibrosis (PPF), a clinicopathological condition distinct yet resembling idiopathic pulmonary fibrosis (IPF). PPF in ANCA-positive ILD (ANCA-ILD) is poorly documented. To clarify incidence, predictors of PPF in ANCA-ILD, and their prognostic impact, 56 patients with ANCA-ILD were followed for ≥ 1 year (April 2004 to April 2021). PPF was defined per ATS/ERS/JRS/ALAT PPF 2022 guideline. We compared PPF and non-PPF in 38 patients with pulmonary function tests and ≥ 1 year follow up. ANCA-ILD (19 male, 19 female; mean age 72 years) comprised 21 patients with microscopic polyangiitis ILD (MPA-ILD) and 17 with ANCA-positive IP without systemic vasculitis (ANCA-IP). PPF occurred in 15/38 (39.5%) overall, and 27% of patients with MPA-ILD and 53% with ANCA-IP. Patient characteristics did not differ between PPF and non-PPF, however, the survival was significantly worse in patients with PPF than those with non-PPF. On multivariate regression analysis, higher age, higher serum SP-D level, and lower baseline %FVC were associated with PPF. In ANCA-ILD, 39.5% of patients demonstrated PPF, which is associated with increased mortality. Predictors of PPF were older age, higher SP-D, and lower baseline %FVC.

ATS/JRS/ALAT Hypersensitivity Pneumonitis Guidelines for Diagnosis of humidifier lung and summer-type hypersensitivity pneumonitis.

BACKGROUND: The ATS/JRS/ALAT Guidelines for the Diagnosis of Hypersensitivity Pneumonitis (GL for HP) were published in 2020. Humidifier lung and summer-type HP are forms of HP, but it is unclear whether they can be diagnosed using GL for HP. This study examined the level of confidence where humidifier lung and summer-type HP can be diagnosed with GL for HP. METHODS: Data from 23 patients with humidifier lung and 20 patients with summer-type HP (mean age, 67.3 and 57.4 years, respectively) diagnosed between October 2012 and January 2022 were retrospectively reviewed. We evaluated high resolution computed tomography (HRCT) patterns, bronchoalveolar lavage fluid (BALF) findings, exposures, and histopathological findings to determine the level of confidence where a diagnosis of HP could be made using the GL for HP. RESULTS: HRCT pattern was classified as typical HP in 5 (22%) and compatible with HP in 18 (78%) patients with humidifier lung and considered as typical HP in 17 (85%) and compatible with HP in 3 (15%) patients with summer-type. The confidence level for diagnosis of HP was definite in 2 (8.7%), moderate in 14 (60.9%), and low in 7 (30.4%) patients with humidifier lung. It was definite in 12 (60%), high in 3 (15%), and moderate in 5 (25%) patients with summer-type HP. CONCLUSIONS: GL for HP showed utility in diagnosing humidifier lung in many patients with a moderate to low confidence. However, there was a definite to high confidence for patients with summer-type HP.

Projected lung area using dynamic X-ray (DXR) with a flat-panel detector system and automated tracking in patients with chronic obstructive pulmonary disease (COPD).

OBJECTIVES: To assess the association of projected lung area (PLA) measured by DXR with demographic data, pulmonary function, and COPD severity, and to generate PLA over time curves using automated tracking. METHODS: This retrospective study recruited healthy volunteers and COPD patients. Participants were classified into three groups: normal, COPD mild and COPD severe. PLA was calculated from the manually traced bilateral lung contours. PLA over time curves were produced using automated tracking, which was used to calculate slope and intercept by approximate line during forced expiration. The correlation of PLA, difference of PLA between end-inspiration and end-expiration (ΔPLA), slope, and intercept with demographic data and pulmonary function tests were investigated. The difference of PLA, ΔPLA, intercept, and slope among three groups were also evaluated. RESULTS: This study enrolled 45 healthy volunteers and 32 COPD patients. COPD severe group had larger PLA in both lungs at tidal/forced end-inspiration/expiration, smaller slope, and larger intercept than normal group (p < 0.001). PLA was correlated with % forced expiratory volume in one second (%FEV1) (rs from -0.42 to -0.31, p ≤ 0.01). ΔPLA in forced breathing showed moderate correlation with vital capacity (VC) (rs = 0.58, p < 0.001), while ΔPLA in tidal breathing showed moderate correlation with %FEV1 (rs = -0.52, p < 0.001) as well as mild correlation with tidal volume (rs = 0.24, p = 0.032). Intercept was slightly underestimated compared with manually contoured PLA (p < 0.001). CONCLUSION: COPD patients had larger PLA than healthy volunteers. PLA and ΔPLA in tidal breathing showed mild to moderate correlation with %FEV1.

Immunoglobulin G4-positive interstitial pneumonia associated with pleuroparenchymal fibroelastosis.

A 79-year-old former smoking Japanese man was admitted to our hospital with a 2-year history of dry cough and dyspnoea on exertion. High-resolution computed tomography of the chest revealed reticulation and perilobular opacity with bronchial wall thickening and ground-glass opacities (GGOs) in both lungs, in addition to subpleural dense consolidation (pleuroparenchymal fibroelastosis-like lesion; PPFE-like lesion) predominantly in the bilateral upper lobes. Serum immunoglobulin G4 (IgG4) was elevated (348 mg/dl). Lung biopsy specimens obtained by video-assisted surgery revealed a mixture of usual interstitial pneumonia (IP) and non-specific IP pattern admixed with PPFE. In addition, immunohistochemical staining of IgG4 showed numerous IgG4-positive plasma cells. Consequently, he was diagnosed with IgG4-positive IP associated with PPFE. We initiated a combination therapy with prednisolone and cyclosporine as a calcineurin inhibitor. During prednisolone tapering, his clinical conditions and GGOs improved gradually over 12 months. However, reticular opacities and PPFE-like lesions remained unchanged, and pulmonary function test findings slightly deteriorated.

Vector-field dynamic x-ray (VF-DXR) using optical flow method in patients with chronic obstructive pulmonary disease.

BACKGROUND: We assessed the difference in lung motion during inspiration/expiration between chronic obstructive pulmonary disease (COPD) patients and healthy volunteers using vector-field dynamic x-ray (VF-DXR) with optical flow method (OFM). METHODS: We enrolled 36 COPD patients and 47 healthy volunteers, classified according to pulmonary function into: normal, COPD mild, and COPD severe. Contrast gradient was obtained from sequential dynamic x-ray (DXR) and converted to motion vector using OFM. VF-DXR images were created by projection of the vertical component of lung motion vectors onto DXR images. The maximum magnitude of lung motion vectors in tidal inspiration/expiration, forced inspiration/expiration were selected and defined as lung motion velocity (LMV). Correlations between LMV with demographics and pulmonary function and differences in LMV between COPD patients and healthy volunteers were investigated. RESULTS: Negative correlations were confirmed between LMV and % forced expiratory volume in one second (%FEV1) in the tidal inspiration in the right lung (Spearman's rank correlation coefficient, rs = -0.47, p < 0.001) and the left lung (rs = -0.32, p = 0.033). A positive correlation between LMV and %FEV1 in the tidal expiration was observed only in the right lung (rs = 0.25, p = 0.024). LMVs among normal, COPD mild and COPD severe groups were different in the tidal respiration. COPD mild group showed a significantly larger magnitude of LMV compared with the normal group. CONCLUSIONS: In the tidal inspiration, the lung parenchyma moved faster in COPD patients compared with healthy volunteers. VF-DXR was feasible for the assessment of lung parenchyma using LMV.

New risk scoring system for predicting 3-month mortality after acute exacerbation of idiopathic pulmonary fibrosis.

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is often fatal. A straightforward staging system for AE-IPF would improve prognostication, guide patient management, and facilitate research. The aim of study is to develop a multidimensional prognostic AE-IPF staging system that uses commonly measured clinical variables. This retrospective study analyzed data from 353 consecutive patients with IPF admitted to our hospital during the period from January 2008 through January 2018. Multivariate analysis of information from a database of 103 recorded AE-IPF cases was used to identify factors associated with 3-month mortality. A clinical prediction model for AE-IPF was developed by using these retrospective data. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of this model. Logistic regression analysis showed that PaO2/FiO2 ratio, diffuse HRCT pattern, and serum C-reactive protein (CRP) were significantly associated with 3-month mortality; thus, PaO2/FiO2 ratio < 250 (P), CRP ≥ 5.5 (C), and diffuse HRCT pattern (radiological) (R) were included in the final model. A model using continuous predictors and a simple point-scoring system (PCR index) was developed. For the PCR index, the area under the ROC curve was 0.7686 (P < 0.0001). The sensitivity of the scoring system was 78.6% and specificity was 67.8%. The PCR index identified four severity grades (0, 1, 2, and 3), which were associated with a 3-month mortality of 7.7%, 29.4%, 54.8%, and 80%, respectively. The present PCR models using commonly measured clinical and radiologic variables predicted 3-month mortality in patients with AE-IPF.

Novel Artificial Intelligence-based Technology for Chest Computed Tomography Analysis of Idiopathic Pulmonary Fibrosis.

Rationale: There is a growing need to accurately estimate the prognosis of idiopathic pulmonary fibrosis (IPF) in clinical practice, given the development of effective drugs for treating IPF. Objectives: To develop artificial intelligence-based image analysis software to detect parenchymal and airway abnormalities on computed tomographic (CT) imaging of the chest and to explore their prognostic importance in patients with IPF. Methods: A novel artificial intelligence-based quantitative CT image analysis software (AIQCT) was developed by applying 304 high-resolution CT (HRCT) scans from patients with diffuse lung diseases as the training set. AIQCT automatically categorized and quantified 10 types of parenchymal patterns as well as airways, expressing the volumes as percentages of the total lung volume. To validate the software, the area percentages of each lesion quantified by AIQCT were compared with those of the visual scores using 30 plain high-resolution CT images with lung diseases. In addition, three-dimensional analysis for similarity with ground truth was performed using HRCT images from 10 patients with IPF. AIQCT was then applied to 120 patients with IPF who underwent HRCT scanning of the chest at our institute. Associations between the measured volumes and survival were analyzed. Results: The correlations between AIQCT and the visual scores were moderate to strong (correlation coefficient 0.44-0.95) depending on the parenchymal pattern. The Dice indices for similarity between AIQCT data and ground truth were 0.67, 0.76, and 0.64 for reticulation, honeycombing, and bronchi, respectively. During a median follow-up period of 2,184 days, 66 patients died, and 1 underwent lung transplantation. In multivariable Cox regression analysis, bronchial volumes (adjusted hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.16-1.53) and normal lung volumes (adjusted HR, 0.97; 95% CI, 0.94-0.99) were independently associated with survival after adjusting for the gender-age-lung physiology stage of IPF. Conclusions: Our newly developed artificial intelligence-based image analysis software successfully quantified parenchymal lesions and airway volumes. Bronchial and normal lung volumes on HRCT imaging of the chest may provide additional prognostic information on the gender-age-lung physiology stage of IPF.

Vector-Field dynamic X-ray (VF-DXR) using Optical Flow Method.

OBJECTIVES: To explore the feasibility of Vector-Field DXR (VF-DXR) using optical flow method (OFM). METHODS: Five healthy volunteers and five COPD patients were studied. DXR was performed in the standing position using a prototype X-ray system (Konica Minolta Inc., Tokyo, Japan). During the examination, participants took several tidal breaths and one forced breath. DXR image file was converted to the videos with different frames per second (fps): 15 fps, 7.5 fps, five fps, three fps, and 1.5 fps. Pixel-value gradient was calculated by the serial change of pixel value, which was subsequently converted mathematically to motion vector using OFM. Color-coding map and vector projection into horizontal and vertical components were also tested. RESULTS: Dynamic motion of lung and thorax was clearly visualized using VF-DXR with an optimal frame rate of 5 fps. Color-coding map and vector projection into horizontal and vertical components were also presented. VF-DXR technique was also applied in COPD patients. CONCLUSION: The feasibility of VF-DXR was demonstrated with small number of healthy subjects and COPD patients. ADVANCES IN KNOWLEDGE: A new Vector-Field Dynamic X-ray (VF-DXR) technique is feasible for dynamic visualization of lung, diaphragms, thoracic cage, and cardiac contour.

Dynamic Chest X-Ray Using a Flat-Panel Detector System: Technique and Applications.

Dynamic X-ray (DXR) is a functional imaging technique that uses sequential images obtained by a flat-panel detector (FPD). This article aims to describe the mechanism of DXR and the analysis methods used as well as review the clinical evidence for its use. DXR analyzes dynamic changes on the basis of X-ray translucency and can be used for analysis of diaphragmatic kinetics, ventilation, and lung perfusion. It offers many advantages such as a high temporal resolution and flexibility in body positioning. Many clinical studies have reported the feasibility of DXR and its characteristic findings in pulmonary diseases. DXR may serve as an alternative to pulmonary function tests in patients requiring contact inhibition, including patients with suspected or confirmed coronavirus disease 2019 or other infectious diseases. Thus, DXR has a great potential to play an important role in the clinical setting. Further investigations are needed to utilize DXR more effectively and to establish it as a valuable diagnostic tool.

Effectiveness of pirfenidone for idiopathic pulmonary fibrosis associated with pleuroparenchymal fibroelastosis-like lesions and nonspecific interstitial pneumonia.

BACKGROUND: Pirfenidone treatment can slow decline in forced vital capacity (FVC) in idiopathic pulmonary fibrosis (IPF). However, its effects for usual interstitial pneumonia (UIP) with pleuroparenchymal fibroelastosis-like lesions (UIP+PPFELL) and UIP with nonspecific interstitial pneumonia (UIP+NSIP) are unclear. OBJECTIVES: The aim of study is to assess pirfenidone effectiveness for UIP+PPFELL and UIP+NSIP. METHODS: We retrospectively analysed data from 58 IPF patients treated with pirfenidone more than 6 months. The outcomes of interest were 6-month follow-up pulmonary function test results, progression-free survival (PFS) and overall survival (OS). Treatment was considered effective if FVC decline was <5% during the 6-month period. We compared clinical characteristics, effectiveness, PFS and OS between patients with typical IPF (n = 32), UIP+PPFELL (n = 12) and UIP+NSIP (n = 14). RESULTS: Data from 58 IPF patients were analysed. At the 6-month follow-up examination, treatment was deemed effective for 9 of 14 (64%) UIP+NSIP patients, 6 of 12 (50%) UIP+PPFELL patients and 14 of 32 (44%) patients with typical IPF. The 6-month decline in FVC before treatment was greater than that after starting treatment in the UIP+NSIP (-210 vs. -57 mL; P = 0.09), UIP+PPFELL (-370 vs. -89 mL; P = 0.001) and typical IPF (-172 vs. -85 mL; P = 0.37). PFS did not significantly differ between the three groups. OS was significantly shorter for UIP+PPFELL (312 days) than for UIP+NSIP (545 days) and typical IPF (661 days). CONCLUSIONS: Pirfenidone decreased the decline in FVC in patients with UIP+PPFELL and UIP+NSIP, as well as in those with typical IPF. However, outcomes were worse for patients with UIP+PPFELL.

Myeloperoxidase anti-neutrophil cytoplasmic antibody-associated vasculitis with a unique imaging presentation of organizing pneumonia: A case report.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) constitutes a group of blood vessel inflammation diseases of autoimmune origin. Myeloperoxidase (MPO) ANCA is closely related to ANCA associated AAV. The MPO-ANCA positive AAV patients have lung involvement at high rates; however, there are only a few reported cases with organizing pneumonia (OP). A 78-year-old man was presented to our hospital due to a fever of 38 °C despite a whole month of antibiotics treatment. Chest computed tomography image revealed restricted consolidations visible in the middle lobe of the right lung and the upper lobe of the left lung, which suggested an OP pattern. MPO-ANCA and urine occult blood tests were positive. Histopathological examination of the transbronchial biopsy revealed OP and mucus plug. Histological findings on renal biopsy showed necrotizing glomerulonephritis related to AAV. The patient was diagnosed with MPO-ANCA positive AAV and was treated with systemic corticosteroid therapy, from which he recovered rapidly. Thus, when diagnosing OP, the possibility of AAV should be considered by ordering patients' serum ANCA and occult hematuria tests.

Characteristics of non-small-cell lung cancer with interstitial pneumonia: variation in cancer location, histopathology, and frequency of postoperative acute exacerbations in interstitial pneumonia.

BACKGROUND: Non-small-cell lung cancer (NSCLC) has been reported to develop in patients with interstitial pneumonia (IP); however, clinical, radiological, and pathological features remain to be elucidated. METHODS: We retrieved the records of 120 consecutive NSCLC patients associated with IP who underwent surgery at Toranomon Hospital between June 2011 and May 2017. We classified the patients into three groups according to NSCLC location using high-resolution computed tomography: group A, within a fibrotic shadow and/or at the interface of a fibrotic shadow and normal lung; group B, within emphysematous tissue and/or at the interface of emphysematous tissue and normal lung; and group C, within normal lung. In 64 patients, programmed death ligand-1 (PD-L1) status was assessed with immunohistostaining. RESULTS: Most of the patients (89; 70%) were classified as group A. This group tended to have squamous cell carcinoma with the usual interstitial pneumonia (UIP). These cancers were located mainly in the lower lobes and seven of the eight postoperative acute exacerbations (pAE) of IP developed in this group. NSCLC in the group B were mainly squamous cell carcinomas located in the upper lobes. No patient with PD-L1 negative was classified into group B. None of the patients in group C showed UIP. and most of the cancers were adenocarcinoma. The frequency of epidermal growth factor receptor mutation-positive NSCLC was the highest in this group. CONCLUSIONS: The three groups each showed characteristic features in terms of tumor location, histopathology, PD-L1 expression, and frequency of pAEof IP.

Clinical and radiological characteristics of ultrasonic humidifier lung and summer-type hypersensitivity pneumonitis.

BACKGROUND: Ultrasonic humidifier lung is a rare form of hypersensitivity pneumonitis (HP), and its clinical and radiological features are unclear. This study examined the clinical and radiological characteristics of humidifier lung. METHODS: Data from 18 patients with humidifier lung (mean age, 67.3 years) diagnosed during October 2012 through April 2018 were retrospectively reviewed. We compared clinical, laboratory, and CT findings and bronchoalveolar lavage fluid (BALF) characteristics of these patients with those of 19 patients with summer-type HP (mean age, 57.4 years). RESULTS: Cough and dyspnea were the most common symptoms. White blood cell count and serum C-reactive protein titers were higher for humidifier lung than for summer-type HP. Serum levels of Krebs von den Lungen-6 and surfactant protein D were significantly lower for humidifier lung than for summer-type HP. The most common chest CT findings in humidifier lung were ground-glass opacities (88.9%) and mosaic attenuation (50.0%). Centrilobular ground glass nodules were less common in humidifier lung than in summer-type HP (27.8% vs 63.1%; P = 0.043). Peribronchovascular or subpleural nonsegmental consolidation was more frequent in humidifier lung than in summer-type HP (44.4% vs 5.3%; P = 0.013). Lymphocyte fractions in BALF specimens were significantly lower for humidifier lung than for summer-type HP (37.3% vs 69.0%; P < 0.001). Neutrophil fractions were higher for humidifier lung, but the difference was not significant (22.1% vs 8.1%; P = 0.153). The CD4/8 ratio was higher for humidifier lung than for summer-type HP (1.7 vs 0.8; P = 0.003). CONCLUSIONS: The clinical and radiological characteristics of humidifier lung differ from those of summer-type HP.

Detection of Shunting Into Pulmonary Artery on Multidetector Row Computed Tomography Arteriography Before Bronchial Arterial Embolization: A Preliminary Study.

OBJECTIVE: The aim of this study was to investigate the diagnostic performance of detecting systemic arterial pulmonary circulation shunts on multidetector row computed tomography arteriography (MDCTA). METHODS: Thirty-five consecutive bronchial artery embolization sessions with preprocedural MDCTA were performed for 32 patients and 35 sessions. The MDCTA studies with computed tomography value of pulmonary trunk visually lower than that of ascending aorta were defined as "diagnostic MDCTA." Angiographic studies and "diagnostic MDCTA" were evaluated, respectively, for shunting into pulmonary artery. Based on the results of angiographic studies, diagnostic performance of "diagnostic MDCTA" was evaluated. RESULTS: The rate of diagnostic MDCTA was 63% (23 of 35). On "diagnostic MDCTA," sensitivity, specificity, and positive and negative predictive values for detecting shunts were 83% 100%, 100%, 94%, respectively. CONCLUSIONS: Systemic arterial pulmonary circulation shunts were detected on "diagnostic MDCTA" with high sensitivity and specificity.

Projected lung areas using dynamic X-ray (DXR).

BACKGROUND: Dynamic X-ray (DXR) provides images of multiple phases of breath with less radiation exposure than CT. The exact images at end-inspiratory or end-expiratory phases can be chosen accurately. PURPOSE: To investigate the correlation of the projected lung area (PLA) by dynamic chest X-ray with pulmonary functions. MATERIAL AND METHODS: One hundred sixty-two healthy volunteers who received medical check-ups for health screening were included in this study. All subjects underwent DXR in both posteroanterior (PA) and lateral views and pulmonary function tests on the same day. All the volunteers took several tidal breaths before one forced breath as instructed. The outlines of lungs were contoured manually on the workstation with reference to the motion of diaphragm and the graph of pixel values. The PLAs were calculated automatically, and correlations with pulmonary functions and demographic data were analyzed statistically. RESULTS: The PLAs have correlation with physical characteristics, including height, weight and BMI, and pulmonary functions such as vital capacity (VC) and forced expiratory volume in one second (FEV1). VC and FEV1 revealed moderate correlation with the PLAs of PA view in forced inspiratory phase (VC: right, r = 0.65; left, r = 0.69. FEV1: right, r = 0.54; left, r = 0.59). Multivariate analysis showed that body mass index (BMI), sex and VC were considered independent correlation factors, respectively. CONCLUSION: PLA showed statistically significant correlation with pulmonary functions. Our results indicate DXR has a possibility to serve as an alternate method for pulmonary function tests in subjects requiring contact inhibition including patients with suspected or confirmed covid-19.

Miliary opacities in pulmonary sarcoidosis.

Pulmonary sarcoidosis should be considered in the differential diagnosis of miliary opacities in bilateral upper lobes predominance.

IgG4-related disease in the differential diagnosis of lung nodules.

IgG4-related disease is an evolving entity of immune-mediated origin. We report a case of IgG4-related disease mimicking lung cancer with pleural dissemination. A 76-year-old male non-smoker was admitted to our hospital because of chest X-ray abnormality. Chest computed tomography scan showed a lung nodule measuring 26 × 14 mm with tiny nodules on the adjacent pleural surface. Wedge resection by video-assisted thoracoscopic surgery (VATS) was performed to aid diagnosis. Pathological findings of the nodule consisted of lymphoid follicular hyperplasia with lymphoplasmacytic infiltrate, fibrosis, and obstructive vasculitis. Focal and scattered thickening of the pleura with lymphoplasmacytic infiltrate was also observed. The IgG4/IgG ratio in the most prominent area exceeded 80%. Thus, we made a diagnosis of IgG4-related lung and pleural disease. To our knowledge, there has been no report of IgG4-related lung disease mimicking lung cancer with pleural dissemination.

Development of a CT image case database and content-based image retrieval system for non-cancerous respiratory diseases: Method and preliminary assessment.

BACKGROUND: To evaluate the benefits of using a CT image case database (DB) with content-based image retrieval system for the diagnosis of typical non-cancerous respiratory diseases. METHODS: Using this DB, which comprised data on 191 cases covering 69 diseases, 933 imaging findings that contributed to differential diagnoses were annotated. Ten test cases were selected. Image similarity between each marked test case lesion and the lesions of the top 10 retrieved cases were assessed and classified as similar, somewhat similar, or dissimilar by two physicians in consensus. Additionally, the accuracy of five internal medicine residents' abilities to interpret CT findings and provide disease diagnoses with and without the proposed system was evaluated by image interpretation experiments involving five test cases. The rates of concordance between the subjects' interpretations and the correct answers prepared in advance by two specialists in consensus were converted into scores. RESULTS: The mean (± SD) of image similarity among the 10 test cases was as follows: 5.1 ± 2.7 (similar), 2.9 ± 1.0 (somewhat similar), and 2.0 ± 2.4 (dissimilar). Using the proposed system, the subjects' mean score for the correct interpretation of CT findings improved from 15.1 to 28.2 points (p = 0.131) and for the correct disease diagnoses, from 9.3 to 28.2 points (p = 0.034). CONCLUSIONS: Although this was a preliminary small-scale assessment, the results suggest that this system may contribute to an improved interpretation of CT findings and differential diagnosis of non-cancerous respiratory diseases, which are difficult to diagnose for inexperienced physicians.

Limited benefit of CT scans in tuberculosis contact tracing.

OBJECTIVE: The detection of abnormal findings on computed tomography (CT) scans of tuberculosis contacts combined with normal plain radiographs contributes to the early detection of tuberculosis. However, the benefit of the early detection of abnormalities for the prevention of active tuberculosis during follow-up requires evaluation. METHOD: We conducted retrospective comparison of the existence of CT scans of tuberculosis contacts without findings of active tuberculosis on plain radiographs at a hospital in Japan. RESULTS: Among 243 contacts without CT scans, five developed tuberculosis during follow-up. Among 229 contacts with CT scans, 24 were judged as targets of multi-drug therapy since their CT findings were suggestive of active tuberculosis at the time of the CT screening. Among 205 contacts judged as having latent tuberculous infection with CT screening, three developed tuberculosis diseases during follow-up. CONCLUSION: CT scans detected abnormal findings among contacts without abnormalities of plain radiographs but there were some contacts that developed tuberculosis diseases among those with contact investigation including CT scan. The value of CT is equivocal considering the balance of true treatment, overtreatment and harm of radiation.