High-resolution Computed Tomography In Patients Research Articles

Ultrasonic Evaluation of Diaphragm in Patients with Systemic Sclerosis.

The diaphragm is the most important muscle in respiration. Nevertheless, its function is rarely evaluated. Patients with systemic sclerosis (SSc) could be at risk of diaphragmatic dysfunction because of multiple factors. These patients often develop interstitial lung disease (SSc-ILD) and earlier studies have indicated that patients with different ILDs have decreased diaphragmatic mobility on ultrasound (US). This study aimed to evaluate diaphragmatic function in SSc patients using US with regard to the ILD, evaluated with the Warrick score on high-resolution computed tomography (HRCT), and to investigate associations between ultrasonic parameters and dyspnea, lung function, and other important clinical parameters. In this cross-sectional study, we analyzed diaphragm mobility, thickness, lung function, HRCT findings, Modified Medical Research Council (mMRC) dyspnea scale, modified Rodnan skin score (mRSS), autoantibodies, and esophageal diameters on HRCT in patients with SSc. Fifty patients were enrolled in the study. Patients with SSc-ILD had lower diaphragmatic mobility in deep breathing than patients without ILD. The results demonstrated negative correlations between diaphragmatic mobility and mMRC, mRSS, anti-Scl-70 antibodies, esophageal diameters on HRCT, and a positive correlation with lung function. Patients with SSc who experience dyspnea should be evaluated for diaphragmatic dysfunction for accurate symptom phenotyping and personalized pulmonary rehabilitation treatment.

Differentiating combined pulmonary fibrosis and emphysema from pure emphysema: utility of late gadolinium-enhanced MRI

BackgroundDifferentiating combined pulmonary fibrosis with emphysema (CPFE) from pure emphysema can be challenging on high-resolution computed tomography (HRCT). This has antifibrotic therapy implications.MethodsTwenty patients with suspected CPFE underwent late gadolinium-enhanced (LGE) thoracic magnetic resonance imaging (LGE-MRI) and HRCT. Data from twelve healthy control subjects from a previous study who underwent thoracic LGE-MRI were included for comparison. Quantitative LGE signal intensity (SI) was retrospectively compared in regions of fibrosis and emphysema in CPFE patients to similar lung regions in controls. Qualitative comparisons for the presence/extent of reticulation, honeycombing, and traction bronchiectasis between LGE-MRI and HRCT were assessed by two readers in consensus.ResultsThere were significant quantitative differences in fibrosis SI compared to emphysema SI in CPFE patients (25.8, IQR 18.4–31.0 versus 5.3, IQR 5.0–8.1, p < 0.001). Significant differences were found between LGE-MRI and HRCT in the extent of reticulation (12.5, IQR 5.0–20.0 versus 25.0, IQR 15.0–26.3, p = 0.038) and honeycombing (5.0, IQR 0.0–10.0 versus 20.0, IQR 10.6–20.0, p = 0.001) but not traction bronchiectasis (10.0, IQR 5–15 versus 15.0, IQR 5–15, p = 0.878). Receiver operator curve analysis of fibrosis SI compared to similarly located regions in control subjects showed an area under the curve of 0.82 (p = 0.002). A SI cutoff of 19 yielded a sensitivity of 75% and specificity of 86% in differentiating fibrosis from similarly located regions in control subjects.ConclusionLGE-MRI can differentiate CPFE from pure emphysema and may be a useful adjunct test to HRCT in patients with suspected CPFE.

Structured report for chest high-resolution computed tomography in patients with connective tissue disease: Impact on the report quality as perceived by referring clinicians

Rationale and ObjectivesTo evaluate the impact on perceived report quality of referring rheumatologists for a chest high-resolution computed tomography (HRCT) structured report (SR) template for patients with connective tissue disease (CTD), compared to the traditional narrative report (NR). Materials and MethodsWe retrospectively considered 123 HRCTs in patients with CTD. Three radiologists, blinded to the original NRs they wrote during clinical routine, re-reported each HRCT using an SR dedicated template. We then divided all NR-SR couples into three groups (41 HRCT each). Each group was evaluated by one of three rheumatologists (R1, R2, R3), who expressed their perceived report quality for the respective pools of NRs and SRs in terms of completeness, clarity (both on a 10-points scale), and clinical relevance (on a 5-points scale). The Wilcoxon test and the McNemar test were used for statistical analysis. ResultsFor each rheumatologist, SR received higher ratings compared to NR for completeness (median ratings: R1, 10 vs. 7; R2, 10 vs. 8; R3, 10 vs. 6, all p < 0.0001), clarity (median ratings: R1, 10 vs. 7; R2, 10 vs. 8; R3, 10 vs. 7, all p < 0.0001), and clinical relevance (median ratings: R1, 5 vs. 4; R2, 5 vs. 4; R3, 5 vs. 1, all p < 0.0001). After rating dichotomization, the use of SR led to a significant increase (p < 0.01) in completeness, clarity, and clinical relevance as compared to NR, except for clarity as perceived by R2 (p = 1). ConclusionReferring rheumatologists’ perceived report quality for structured reporting of HRCT in patients with CTD was superior to narrative reporting.

Hypersensitivity Pneumonitis High-resolution Computed Tomography Findings, and Their Correlation with the Etiology and the Disease Duration.

Hypersensitivity pneumonitis (HP) is an immune-mediated diffuse parenchymal lung disease induced by inhaled antigens. High-resolution computed tomography (HRCT) is widely used in the diagnosis and follow-up of patients and determining the progression and prognosis of the disease. In this retrospective study, 45 consecutive patients with the final diagnosis of HP, seen at a large tertiary care center during a period of 4 years, were included and their HRCT findings were evaluated. The most common HRCT findings were ground glass opacity and reticulation. Some HRCT patterns were detected more severely in bird fanciers in comparison with other etiologies. There is no "gold standard" for the diagnosis of HP. HRCT findings play an important role in hypersensitivity pneumonitis diagnosis and CT scan also help to define the severity of hypersensitivity pneumonitis injuries. In our study, reticulation and ground glass opacity were the most common findings in HRCT of patients with HP. We also find that patients with avian contacts had a significantly higher rate of fibrosis.

Lymphocytic focus score is positively related to airway and interstitial lung diseases in primary Sjögren's syndrome

Although high-resolution computed tomography (HRCT) is useful for the characterization of minute morphological changes in the lungs, no study has investigated risk factors for lung involvement detected by HRCT in patients with Sjögren's syndrome with or without respiratory symptoms. The aim of the current study was to investigate risk factors for lung involvement in patients with primary Sjögren's syndrome detected by HRCT, with a particular focus on airway and interstitial lung diseases. We performed a retrospective cohort study of patients with primary Sjögren's syndrome and investigated risk factors for lung involvement detected by HRCT. A total of 101 patients with primary Sjögren's syndrome with initial HRCT examinations were enrolled. Higher age, dry mouth, and higher labial gland biopsy focus scores (≥4) were risk factors for airway diseases (odds ratio [OR] 1.064 confidence interval [CI] 1.026-1.102, OR 8.795 CI 2.317-33.378 and OR 3.261 CI 1.100-9.675, respectively) in the multivariable analysis. Higher age, male sex, and higher labial gland biopsy focus scores (≥4) were risk factors for interstitial lung diseases (OR 1.078 CI 1.032-1.127, OR 12.178 CI 1.121-132.307 and OR 3.954 CI 1.423-10.987, respectively) in the multivariable analysis. The presence of anti-T-lymphotropic virus type 1 antibodies was significantly more common in patients with airway diseases. This study showed significant associations of labial gland biopsy focus scores and dry mouth with pulmonary manifestations in patients with primary Sjögren's syndrome. Focus scores as well as dry mouth may reflect lymphoproliferative activity in the lungs in patients with primary Sjögren's syndrome.

Comparison of endobronchial ultrasound and high resolution computed tomography as tools for airway wall imaging in asthma and chronic obstructive pulmonary disease

IntroductionAirway remodeling in asthma and chronic obstructive pulmonary disease (COPD) results in bronchial wall thickening. Bronchial wall thickness (BWT) can be assessed in high-resolution computed tomography (HRCT) and endobronchial ultrasound (EBUS). AimsTo compare BWT measured by EBUS and HRCT in patients with mild-to-moderate asthma and COPD, and to evaluate the relationship between the BWT and pulmonary function. MethodsThe study included patients with mild-to-moderate asthma (n = 24), COPD (n = 36) and controls (n = 12). Bronchoscopy with EBUS (radial probe) and HRCT were performed to measure the BWT in the segmental bronchus. ResultsGood overall agreement between EBUS and HRCT measurements of BWT was demonstrated. Median HRCT-BWT did not reveal any significant differences between individuals with asthma and COPD, and control subjects: 1.56 (1.27–1.70) mm, 1.62 (1.45–1.90) mm, and 1.63 (1.41–1.77) mm, respectively (p = 0.315). In contrast, median BWT measured by EBUS was significantly higher in asthma and COPD groups when compared to controls: 1.20 (1.02–1.41) mm, 1.19 (1.10–1.48) mm, and 0.99 (0.90–1.08) mm, respectively (p = 0.006). There were no differences in BWT in mild-to-moderate asthma and COPD or significant correlations between BWT and the results of pulmonary function tests. ConclusionsThe use of EBUS to assess BWT in asthma and COPD is feasible and it shows good compatibility with HRCT. A tendency towards lower BWT values in EBUS when compared to HRCT was observed. The finding that EBUS measurements demonstrated the differences between BWT in patients with obstructive lung diseases and controls, may suggest that EBUS is a more sensitive method to study the BWT than HRCT.

Esophageal dilatation and interstitial lung disease in systemic sclerosis: A cross-sectional study.

A patulous esophagus on high-resolution computed tomography (HRCT) of the thorax is frequently observed in patients with systemic sclerosis (SSc). Microaspiration has been purported to play a role in the development and progression of SSc interstitial lung disease (ILD), but studies examining the role of microaspiration in SSc ILD have yielded conflicting results. This study was conducted to determine the association between esophageal diameter and SSc ILD. A cross-sectional study of Northwestern Scleroderma Registry patients with available HRCT exams was conducted. The predictor variable was the widest esophageal diameter (WED) on HRCT, and the primary and secondary outcome variables were radiographic ILD and pulmonary function tests respectively. The degree of radiographic ILD was assessed using a semi-quantitative score adapted from published methods. Estimated regression coefficients adjusted for age, sex, race, body mass index, smoking; SSc disease subtype, serum autoantibodies, and disease duration; modified Rodnan skin score, proton pump inhibitor, and immune suppressant medication use and erythrocyte sedimentation rate were calculated. A total of 270 subjects were studied. In the adjusted analyses, there were positive associations between WED and total ILD score (β = 0.27; 95% CI: 0.09-0.41), fibrosis (β = 0.15; 95% CI: 0.07-0.23), and ground glass opacities (β = 0.12; 95% CI: 0.04-0.20); there were negative associations between WED and FVC % predicted (β = -0.42; 95% CI: -0.69 to -0.13), and adjusted DLCO % predicted (β = -0.45; 95% CI: -0.80 to -0.09) after adjusting for potential confounders. Increasing esophageal diameter on HRCT in patients with SSc is associated with more severe radiographic ILD, lower lung volumes, and lower DLCO % predicted. Longitudinal studies are needed to determine if esophageal dilatation is associated with the incidence and/or progression of ILD in patients with SSc.

Brief Report: Pulmonary Function Tests: High Rate of False-Negative Results in the Early Detection and Screening of Scleroderma-Related Interstitial Lung Disease.

Validated methods for the screening and early diagnosis of systemic sclerosis (SSc; scleroderma)-related interstitial lung disease (ILD) are needed. The aim of this study was to evaluate the performance of pulmonary function tests (PFTs) compared with that of high-resolution computed tomography (HRCT) of the chest for the detection of SSc-related ILD in clinical practice, and to identify predictors of lung involvement that is functionally occult but significant on HRCT. Prospectively enrolled patients with SSc were assessed according to the European League Against Rheumatism (EULAR)/EULAR Scleroderma Trial and Research standards. The assessment included PFTs and HRCT. The HRCT images were evaluated in a blinded manner by 2 experienced radiologists. The performance parameters of PFTs for the diagnosis of SSc-related ILD were calculated. Predictors of significant ILD as determined by HRCT in patients with normal forced vital capacity (FVC) values were identified through logistic regression. Among the 102 patients, 64 (63.0%) showed significant ILD on HRCT, while only 27 (26.0%) had an FVC <80% of predicted, and 54 (53.0%) had a decrease in the results of at least 1 PFT. Forty (62.5%) of 64 patients with significant ILD on HRCT had a normal FVC value, translating into a high false-negative rate. Notably, 5 of 40 patients with a normal FVC value had severe, functionally occult lung fibrosis; in 2 of these patients, the results of all of the PFTs were within normal limits. Patients with normal FVC values despite evidence of fibrosis on HRCT more frequently had anti-Scl-70 antibodies and diffuse SSc and less frequently had anticentromere antibodies (ACAs) compared with patients with both normal FVC values and normal HRCT results. The derived evidence-based data reveal a high risk of missing significant SSc-related ILD when relying solely on PFTs. More comprehensive screening algorithms for early detection are warranted. In particular, additional imaging investigations for the early detection of SSc-related ILD should be considered in ACA-negative patients with normal FVC values.

AB0633 Association of Decrease Diffusing Lung Capacity with Progression Pulmonary Alterations by HRCT in Patients with Systemic Sclerosis over A Five-Year Period

BackgroundFunctional lung tests play a one of the key role in assessment of SS pulmonary manifestations. As many as 90% of pts will have interstitial abnormalities on HRCT and 40-75%...

Airway remodeling assessed by high-resolution computed tomography in patients with asthma: relationship to biological markers in induced sputum

To explore the significance of assessing asthma control by high-resolution computed tomography (HRCT) and biological markers in induced sputum. Forty-eight patients with asthma (asthma group) and 10 healthy subjects (control group) were retrospectively analyzed. The asthma patients were divided into 4 groups based on severity: 6 with near-fatal attacks, 12 with severe, 14 with moderate and 16 with mild asthma. These patients received step therapy for 6 months based on the guidelines for the prevention and treatment of asthma. After achieving asthma control or partial control, HRCT, lung function and cytokine levels in induced sputum were measured. The ratio of wall area to total airway area (WA%), the ratio of 2 airway wall thickness to outer diameter (2T/D) and lung densities in both the inspiratory and expiratory phases were measured. Matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinases-1 (TIMP-1), and transformation growth factor-β(1) (TGF-β(1)) levels in the sputum were assessed by enzyme-linked immunosorbent assay. There were significant differences in forced vital capacity and forced expiratory volume in 1 second as the percentage of predicted value (FVC% and FEV(1)%, respectively), the ratio of FEV(1)/FVC, and diffusing capacity of the lung for carbon monoxide (D(LCO)) among groups (F = 5.526, 15.064, 16.326, 2.945, respectively, P < 0.05). Sputum levels of MMP-9, TIMP-1 and TGF-β(1) were significantly increased in the near-fatal asthma, severe asthma, moderate asthma and mild asthma groups [MMP-9: (80 ± 16), (70 ± 9), (59 ± 6), and (52 ± 7) µg/L, respectively; TIMP-1: (212 ± 95), (258 ± 167), (28 ± 51), and 98 ± 60 µg/L, respectively; TGF-β(1): (586 ± 81), (513 ± 54), (401 ± 45) and (351 ± 57) µg/L, respectively]compared with the control group [MMP9: (46 ± 5) µg/L; TIMP: (19 ± 13) µg/L; and TGF-β(1): (258 ± 29) µg/L]. These parameters were progressively increased in the asthma groups with the severity of disease (F = 11.179, 49.914, 9.286, respectively, P < 0.05). The ratio of MMP-9/TIMP-1 in sputum was decreased in the near-fatal attack, severe, moderate and mild asthma groups (0.50 ± 0.28, 0.34 ± 0.13, 0.53 ± 0.22, and 0.87 ± 0.75, respectively) compared with the control group (2.93 ± 1.13). The MMP-9/TIMP-1 ratio in the severe asthma group was lowest among the asthma groups (F = 43.335, P < 0.05). 2T/D and WA% were higher in both the near-fatal asthma group (0.51 ± 0.01 and 0.75 ± 0.01, respectively) and the severe asthma group (0.53 ± 0.03 and 0.77 ± 0.03, respectively) as compared to the moderate asthma group (0.43 ± 0.04 and 0.67 ± 0.04, respectively) or the mild group (0.42 ± 0.04 and 0.66 ± 0.04, respectively). 2T/D and WA% were higher in the asthma groups than in the control group (0.35 ± 0.03 and 0.57 ± 0.04, respectively), (F = 40.224, 41.294, respectively, P < 0.05). Lung densities in both the inspiratory and expiratory phases were lower in the near-fatal attack group as compared to those in the other asthma groups or the control group; and the lung density differences between the two phases in the near-fatal attack group were smaller than those in the other asthma groups or the control group (F = 5.048, 13.247, 11.541, respectively, P < 0.05). 2T/D and WA% were correlated positively with MMP-9, TIMP-1 and TGF-β(1) levels, but negatively with the MMP-9/TIMP-1 ratio, respectively. HRCT and biological markers in induced sputum could be used to accurately evaluate asthma control. These findings suggest that the severity of asthma, especially, near-fatal attack of asthma, is correlated not only with the degree of airway remodeling, but also with the degree of air trapping.

High-resolution computed tomography in rheumatoid arthritis

Dear Editor,We have read with great interest the recent study of Leonelet al. [1] revealing correlation of pulmonary function testwith pulmonary high-resolution computed tomography inpatients with rheumatoid arthritis. Authors revealed thatforced expiratory volume in 1 s (FEV1) was significantlyassociated with high-resolution computed tomography(HRCT) alterations, and methotrexate use and time evolu-tion of the disease have been associated with altered FEV1.In our opinion, some points about computed tomography(CT) scanning in this article are not sufficiently clear.In their study, authors did not mention the type of theCT scanner-conventional high-resolution CT or helicalhigh-resolution multi-detector CT (MDCT) and did notgive information about the use of typical high specialalgorithm for HRCT image. They used 2-mm collimationthickness for scanning; however, thin collimation of1.5 mm or less in HRCT is essential to visualize subtlelung findings as decreased collimation thickness reducesvolume averaging artifacts and increases the spatial reso-lution in the images [2].Position of the patient at CT scan was not stated in themanuscript though the patient position might be vital insuch an imaging procedure since prone position could benoteworthy for optimal evaluation of ground-glass opacitiesbesides frequent standard supine position. All the imageswere obtained with deep inspiration of patients in the study;however, images could also be obtained during dynamicexpiration or at static end-expiration to evaluate for airtrapping in the lung parenchyma.It is well known that air trapping and mosaic perfusion,esophageal dilation, enlargement of mediastinal lymphnodes, dilation of pulmonary artery, and pleural effusioncan also be determined with HRCT in patients with RA,though Leonel et al. did not denote such findings.We hope that above-mentioned comments will add tothe value of the article by Leonel et al.References

Ventilation/perfusion SPECT in chronic obstructive pulmonary disease: an evaluation by reference to symptoms, spirometric lung function and emphysema, as assessed with HRCT

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation which is not fully reversible. Despite the heterogeneity of COPD, its diagnosis and staging is currently based solely on forced expiratory volume in 1 s (FEV(1)). FEV(1) does not explain the underlying pathophysiology of airflow limitation. The relationship between FEV(1), symptoms and emphysema extent is weak. Better diagnostic tools are needed to define COPD. Tomographic lung scintigraphy [ventilation/perfusion single photon emission tomography (V/P SPECT)] visualizes regional V and P. In COPD, relations between V/P SPECT, spirometry, high-resolution computed tomography (HRCT) and symptoms have been insufficiently studied. The aim of this study was to investigate how lung function imaging and obstructive disease grading undertaken using V/P SPECT correlate with symptoms, spirometric lung function and degree of emphysema assessed with HRCT in patients with COPD. Thirty patients with stable COPD were evaluated with the Medical Research Council dyspnoea questionnaire (MRC) and the clinical COPD questionnaire (CCQ). Spirometry was performed. The extent of emphysema was assessed using HRCT. V/P SPECT was used to assess V/P patterns, total reduction in lung function and degree of obstructive disease. The total reduction in lung function and degree of obstructive disease, assessed with V/P SPECT, significantly correlated with emphysema extent (r = 0.66-0.69, p < 0.0001) and spirometric lung function (r = 0.62-0.74, p < 0.0005). The correlation between emphysema extent and spirometric lung function was weaker. No correlation between MRC, CCQ and objective measurements was found. V/P SPECT is sensitive to early changes in COPD. V/P SPECT also has the possibility to identify comorbid disease. V/P SPECT findings show a significant correlation with emphysema extent and spirometric lung function. We therefore recommend that scintigraphic signs of COPD, whenever found, should be reported. V/P SPECT can also be used to categorize the severity of functional changes in COPD as mild, moderate or severe.

High-resolution computed tomography findings in an HIV-positive patient with Swine-origin Influenza A (H1N1) virus-associated pneumonia

To the Editor: Since the introduction of highly active antiretroviral therapy, morbidity and mortality from human immunodeficiency virus (HIV) disease and various associated opportunistic infections have decreased significantly. The 2009 Swine-origin influenza A (H1N1) pandemic is the first to occur since the emergence of HIV/AIDS. A 35-year-old HIV-positive man presented with a four-day history of fever, chills, fatigue, anorexia and mild dyspnea, without cough or chest pain. He was in significant respiratory distress. Physical examination revealed tachypnea, tachycardia, fever of 101.5°F (38.6°C), oxygen saturation on room air of 88%, and crackles in both lungs. Laboratory tests revealed leucopenia, C-reactive protein of 6.1 mg dL–1 and lactate dehydrogenase of 940 IU L–1. Chest X-ray was considered normal. High-resolution CT showed mild ground-glass opacities in both lower lobes, predominantly in the right lung (Figure 1). Bronchoalveolar lavage was negative for Pneumocystis jiroveci, mycobacteria, and malignancy. Real-time polymerase chain reaction confirmed the infection with novel H1N1 virus. Figure 1 High-resolution CT shows mild ground-glass opacities in both lower lobes, predominantly in the right lung. Early data suggest that people co-infected with H1N1 and HIV are not at increased risk of severe or fatal illness when receiving antiretroviral therapy. In most cases, illness caused by H1N1 has been mild, with full recovery [1]. However, HIV-infected individuals may be at higher risk for more severe disease and complications from H1N1 flu virus [2, 3]. Lung infection is an significant cause of morbidity and mortality in patients with advanced HIV infection. Among these patients, Pneumocystis jiroveci pneumonia (PCP) is the most frequent AIDS-defining infection. The clinical symptoms of PCP in HIV-infected patients are non-specific and similar to many other infectious processes. Since empirical treatment for these infections is not devoid of complications, it is necessary to carry out diagnostic tests before effective specific treatment can be established [4]. High-resolution computed tomography (HRCT) is a reliable method for differentiating PCP from other infectious processes in HIV-positive patients. Although ground-glass attenuation on HRCT of patients with AIDS can be the result of several other abnormalities, such as cytomegalovirus (CMV) pneumonia or lymphocytic interstitial pneumonitis, this pattern is considered virtually diagnostic of PCP in most cases [4, 5]. In this case, H1N1 virus-associated pneumonia appeared as ground-glass opacities on HRCT. This infection should be included in the differential diagnosis of pulmonary infections that cause ground-glass opacities in patients with HIV/AIDS.

Nonspecific interstitial pneumonia pattern as pulmonary involvement of rheumatoid arthritis

The pathologic patterns of lung involvement were evaluated in 16 patients with rheumatoid arthritis (RA). They consisted of six females and ten males, with a median age of 67.5 years and diagnosed according to the American Rheumatism Association revised criteria. High-resolution computed tomography (HRCT) of the lungs was performed in all patients, and honeycomb formation was apparent in seven. Histopathologically, seven patients were diagnosed with usual interstitial pneumonia (UIP) pattern, seven with nonspecific interstitial pneumonia/fibrosis (NSIP) pattern, and two with UIP/NSIP hybrid pattern. There were no apparent honeycomb formations on HRCT in patients diagnosed with NSIP pattern. In conclusion, the present study demonstrates that NSIP pattern is also a significant histologic classification of interstitial pneumonia associated with RA.

Utility of High-Resolution CT for Management of Diffuse Lung Disease: Results of a Survey of U.S. Pulmonary Physicians

Rationale and Objectives This study was performed to determine how U.S. pulmonologists rate the clinical contributions of high-resolution computed tomography (CT) in patients with diffuse lung disease, to ascertain how the technique affects management decisions, and to determine the effect of three physician characteristics on these attitudes. Materials and Methods The authors surveyed 450 practicing pulmonologists. The questionnaire explored perceptions of the efficacy of high-resolution CT for achieving five clinical objectives, the importance of high-resolution CT in 17 diseases, and the effects of the CT results on management decisions. Responses were examined by type of clinical practice, monthly referral volume, and year of completion of pulmonary fellowship. Results The response rate was 52.6%. High-resolution CT was rated most helpful for determining the extent of diffuse lung disease and least helpful for assessing disease activity and prognosis. Pulmonologists believed that high-resolution CT was most important in the idiopathic interstitial pneumonias and least important in Pneumocystis carinii pneumonia and emphysema. High-resolution CT results frequently increased the physician's confidence in a presumptive diagnosis. Recently trained pulmonologists were more likely to report that high-resolution CT results altered their management plan. There were no significant differences related to type of practice. Conclusion U.S. pulmonologists in a variety of practice settings value the contributions of high-resolution CT in patients with diffuse lung disease and find it particularly important in the chronic interstitial pneumonias. High-resolution CT results have their greatest effect in confirming a presumptive clinical diagnosis and less frequently alter the management plan.

Availability, Requesting Practices, and Barriers to Referral for High-Resolution CT of the Lungs: Results of a Survey of U.S. Pulmonologists

Rationale and Objectives The authors performed this study to assess the availability of high-resolution computed tomography (CT), current referral practices, and potential barriers to the clinical use of high-resolution CT in patients with diffuse lung disease. Materials and Methods The authors sent a survey to 450 pulmonologists who were members of the American College of Chest Physicians. They sought information about the availability of high-resolution CT services, explored the physicians' current requesting practices and the monthly number of referrals, and assessed the influence of six factors on the decision to refer. Results The authors received completed surveys from 230 pulmonologists (52.6%). High-resolution CT services were available to all respondents and had been used by 226 (98.3%) of them during the preceding 12 months. Two-thirds of respondents referred one to four patients per month, and one-third referred five or more. Monthly referral volume did not significantly vary among different practice types. The pulmonologists expressed a preference for hospital-based imaging facilities and routinely reviewed the images from the examinations they ordered. The most frequent reason for high-resolution CT was classification of a known interstitial process. High-resolution CT was infrequently requested to evaluate symptomatic immunocompromised patients. Confidence in the radiologist's high-resolution CT interpretation was the most important factor influencing the referral decision, and radiation dose to the patient was the least important. Conclusion High-resolution CT services are widely available to and frequently requested by U.S. pulmonologists in a variety of practice settings. High-resolution CT may be underutilized in symptomatic immunocompromised patients. Radiologists should be aware that the perception of their skill in high-resolution CT interpretation is an important determinant in the pulmonologist's decision to refer.