High-resolution CT quantification of bronchiectasis: clinical and functional correlation

[Bronchial diseases: CT imaging features]

Multidetector row computed tomography (MDCT) is the imaging modality of reference for the diagnosis of bronchiectasis. MDCT may also detect a focal stenosis, a tumor or multiple morphologic abnormalities of the bronchial tree. It may orient the endoscopist towards the abnormal bronchi, and in all cases assess the extent of the bronchial lesions. The CT findings of bronchial abnormalities include anomalies of bronchial division and origin, bronchial stenosis, bronchial wall thickening, lumen dilatation, and mucoid impaction. The main CT features of bronchiectasis are increased bronchoarterial ratio, lack of bronchial tapering, and visibility of peripheral airways. Other bronchial abnormalities include excessive bronchial collapse at expiration, outpouchings and diverticula, dehiscence, fistulas, and calcifications.

Exhaled breath condensate MMP-9 levels in children with bronchiectasis

Bronchiectasis (BE) is still an important cause of chronic supurative respiratory diseases in developing countries. Neutrophil-derived proteases such as neutrophil elastase and matrix metalloproteases (MMPs) are implicated in causing airway damage in chronic pulmonary disease. In this study, we aimed to evaluate the MMP-9 and its natural tissue inhibitors of metalloproteinases (TIMP-1) levels utilizing the exhaled breath condensate (EBC) method and their relationship with radiological findings and pulmonary functions in children with BE.Thirty-eight children with BE and 12 healthy children were included: Group 1 (cystic fibrosis [CF] BE), Group 2 (non-CF BE), Group 3 (control group). High-resolution computerized tomography (HRCT) scores were calculated according to the anatomic extent of BE. Pulmonary function tests were performed, and MMP-9 and TIMP-1 levels in EBC were analyzed by ELISA.Exhaled breath condensate MMP-9 level was 48.9 +/- 26.8 ng/ml for Group 1, and for Group 2, 42.8 +/- 18.1 ng/ml; and for Group 3, 30 +/- 3.7 ng/ml. Although no statistically significant difference was found between the Groups 1 and 2, a significant difference was detected between these groups and controls. No statistically significant difference was found in TIMP-1 levels regarding all groups. EBC MMP-9 levels were inversely correlated with pulmonary functions test, and positively with HRCT scores and annual number of pulmonary infections.In conclusion, this study showed that EBC of children with both CF BE and non-CF BE contained higher levels of MMP-9 in comparison to controls. We suggest that EBC MMP-9 level may be a useful marker of airway injury in patients with BE however prospective studies are needed.

Development and validation of automated 2D-3D bronchial airway matching to track changes in regional bronchial morphology using serial low-dose chest CT scans in children with chronic lung disease

To address potential concern for cumulative radiation exposure with serial spiral chest computed tomography (CT) scans in children with chronic lung disease, we developed an approach to match bronchial airways on low-dose spiral and low-dose high-resolution CT (HRCT) chest images to allow serial comparisons. An automated algorithm matches the position and orientation of bronchial airways obtained from HRCT slices with those in the spiral CT scan. To validate this algorithm, we compared manual matching vs automatic matching of bronchial airways in three pediatric patients. The mean absolute percentage difference between the manually matched spiral CT airway and the index HRCT airways were 9.4 ± 8.5% for the internal diameter measurements, 6.0 ± 4.1% for the outer diameter measurements, and 10.1 ± 9.3% for the wall thickness measurements. The mean absolute percentage difference between the automatically matched spiral CT airway measurements and index HRCT airway measurements were 9.2 ± 8.6% for the inner diameter, 5.8 ± 4.5% for the outer diameter, and 9.9 ± 9.5% for the wall thickness. The overall difference between manual and automated methods was 2.1 ± 1.2%, which was significantly less than the interuser variability of 5.1 ± 4.6% (p<0.05). Tests of equivalence had p<0.05, demonstrating no significant difference between the two methods. The time required for matching was significantly reduced in the automated method (p<0.01) and was as accurate as manual matching, allowing efficient comparison of airways obtained on low-dose spiral CT imaging with low-dose HRCT scans.

Physiology of the small airways: A gender difference?

Small airways are affected in asthma, but gender differences have not been investigated. This study aims to assess whether gender differences exist in the extent of small airway involvement in asthma. Sixteen patients with mild-to-moderate asthma (seven males, median (range) age 39 (19-56) years, FEV(1)%predicted 89% (62-120), PC(20) Methacholine (MCh) 0.4 mg/mL (0.1-4.2)) participated in the study. MCh-induced air trapping at end-expiratory CT scans, alveolar and bronchial exhaled Nitric Oxide (eNO), Single-Breath N(2) closing volume, FEF(25-75%), FEF(50%) and % change in FVC at PC(20) adenosine-5'-monophosphate (AMP) and at PC(20)MCh were evaluated. Multiple regression analyses evaluated whether gender, body mass index and age were explanatory variables for the severity of air trapping. Males had significantly larger MCh-induced increases in low attenuation areas on CT than females, 6% (1-9) versus 2% (-1-7), p=0.012. Males had significantly more signs of MCh-induced air trapping in the non-dependent lung lobes than females. Male gender was the sole factor explaining higher values of MCh-induced signs of air trapping. Females had higher bronchial eNO values than males, 4 nL/s (2-7) versus 2 nL/s (1-4), p=0.04. Small airway involvement in asthma as reflected by MCh-induced air trapping at CT was significantly larger in males than females even in this relatively small group. Bronchial eNO, reflecting partially small airway inflammation, was higher in females than males. These data suggest that the small airways are affected differently in males and females with asthma. Males exhibit small airway involvement by attenuated small airway patency and females by small airway inflammation.

Right and left ventricular function and pulmonary artery pressure in patients with bronchiectasis

BACKGROUND

Bronchiectasis may have deleterious effects on cardiac function secondary to pulmonary hypertension (PH). This study was designed to assess cardiac function and determine the prevalence of PH in patients with cystic and cylindrical bronchiectasis.

METHODS

A cross-sectional study of patients with bronchiectasis diagnosed by CT scan was conducted at King Khalid University Hospital, Riyadh, Saudi Arabia between December 2005 and January 2007. Pulmonary function tests were performed, arterial blood gas measurements were made, and cardiac function and systolic pulmonary artery pressure (SPAP) were assessed by echocardiography.

RESULTS

Of 94 patients (31% men, n = 29), 62 patients (66%) had cystic bronchiectasis and 32 patients (34%) had cylindrical bronchiectasis. Right ventricular (RV) systolic dysfunction was observed in 12 patients (12.8%), left ventricular (LV) systolic dysfunction was observed in 3 patients (3.3%), and LV diastolic dysfunction was observed in 11 patients (11.7%); all had cystic bronchiectasis. RV dimensions were significantly greater in the cystic bronchiectasis group, and were positively correlated with SPAP (p < 0.0001) and negatively correlated with Pao2 (p < 0.016). Other hemodynamic variables were not different between groups. PH in 31 patients (32.9%) was significantly greater in patients with cystic bronchiectasis compared with cylindrical bronchiectasis (p = 0.04). In cystic bronchiectasis, SPAP was positively correlated with Paco2 (p = 0.001), and inversely correlated with Pao2 (p = 0.03), diffusion capacity of the lung for carbon monoxide percentage (p = 0.02), and FEV1 (p = 0.02).

CONCLUSIONS

RV systolic dysfunction and PH were more common than LV systolic dysfunction in bronchiectatic patients. LV diastolic dysfunction was mainly seen in severe PH. We recommend detailed assessment of cardiac function, particularly LV diastolic function, in patients with bronchiectasis.

Prevalence and impact of bronchiectasis in alpha1-antitrypsin deficiency

RATIONALE

alpha(1)-Antitrypsin (AAT) deficiency is associated with increased risk of chronic obstructive pulmonary disease (COPD), in particular emphysema, but airway disease is less well described.

OBJECTIVES

To assess the prevalence of airways disease in subjects with AAT deficiency and to identify the relationship between radiological airway abnormalities and clinical phenotype.

METHODS

We characterized the computed tomographic phenotype of 74 subjects (PiZ), using visual scoring of airway disease and densitometric assessment of emphysema. Computed tomographic measurements were related to physiology, health status (St. George's Respiratory Questionnaire), and emphysema severity, and the relative impact of airway disease and emphysema severity on health status and airflow obstruction was compared by stepwise regression.

MEASUREMENTS AND MAIN RESULTS

Bronchiectatic changes were seen in 70 subjects, and a subgroup with a bronchiectasis-predominant phenotype was identified. Clinically significant bronchiectasis (radiologic bronchiectasis in 4 or more bronchopulmonary segments together with symptoms of regular sputum production) occurred in 20 subjects (27%). AAT-deficient index cases had higher airway disease scores (P < 0.05), more severe emphysema (P < 0.001), and greater impairment of physiology (P < 0.001) and health status (P < 0.05) than nonindex cases. Airway disease scores correlated with health status, and bronchial wall thickening correlated with FEV(1). Regression analysis indicated that emphysema severity had the strongest associations for health status (r = 0.505, P < 0.001) and FEV(1) (r = 0.699, P < 0.001), but the addition of airway disease score improved the regression models (r = 0.596, P = 0.002 and r = 0.783, P < 0.001, respectively).

CONCLUSIONS

Emphysema is the predominant component of COPD in AAT deficiency, but the prevalence and impact of airway disease are greater than currently recognized. Consequently, future therapeutic strategies in AAT deficiency should also target this component of COPD.

Exhaled breath condensate 8-isoprostane, clinical parameters, radiological indices and airway inflammation in COPD

BACKGROUND

Exhaled breath condensate (EBC) 8-isoprostane levels were found increased in chronic obstructive pulmonary disease. However, the relation between EBC 8-isoprostane and parameters which have a known predictive value in COPD, remains vastly unknown, and so does subsequently its clinical value.

OBJECTIVES

To investigate the relationship between 8-isoprostane level in EBC and clinical parameters, radiological indices and airway inflammation in COPD patients.

MATERIALS AND METHODS

We studied 18 COPD patients (all ex-smokers) and 12 healthy controls (5 ex-smokers and 7 never-smokers). All patients underwent clinical evaluation, sputum induction, high-resolution computed tomography (HRCT) of the thorax and EBC 8-isoprostane measurement. 8-Isoprostane levels were correlated with markers that reflect disease severity, such as dyspnea severity, FEV(1) (%pred), emphysema changes and bronchiectasis in HRCT. Emphysema was quantified as the percentage of lung area with attenuation values < -950 Hounsfield units.

RESULTS

8-Isoprostane levels were significantly elevated in EBC of patients with COPD [mean (SE) 18.1 (2) vs. 5.6 (0.7) pg/ml, p = 0.0001], irrespective of lung function impairment. 8-Isoprostane levels were correlated with emphysema score in HRCT (r(2) = 0.43, p = 0.001) as well as with Medical Research Council dyspnea scale score (rho = 0.61, p = 0.005).

CONCLUSION

Our findings suggest that EBC 8-isoprostane levels may reflect the extension of lung emphysema in COPD patients. In this respect, further investigation is required in order to evaluate the possible role of EBC 8-isoprostane in assessing disease progress in COPD patients.

Bronchiectasis and sino-nasal disease: a review

The 'one airway' model for upper and lower respiratory tract disease is a concept gaining increasing momentum in both respiratory medicine and otorhinolaryngology. The specific common aetiology and pathophysiology of concomitant bronchiectasis and sino-nasal disease, such as chronic rhinosinusitis, are discussed here, as well as the clinical manifestations, along with a review of all the relevant literature in the field.

Association between inflammatory markers in induced sputum and clinical characteristics in children with non-cystic fibrosis bronchiectasis

To study clinical, radiological and laboratory features of children with non-cystic fibrosis (non-CF) bronchiectasis (BE) and the association between symptom scores, spirometry, high-resolution computed tomography (HRCT) findings and inflammatory markers in induced sputum in these children. Twenty-seven children with steady-state non-CF BE were cross-sectionally evaluated by symptom scores, pulmonary function tests, anatomic extension and severity scores of BE in HRCT and tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) levels in induced sputum. There were 16 girls and 11 boys. Median (interquartile range) age of study group was 11.4 (9.5-13.6) years, follow-up duration was 3.5 (2-6.5) years and symptom scores were 4 (3-6). Pulmonary function tests revealed FEV(1) of 82%pred (72-93), FVC of 82%pred (74-92), and FEF(25-75%) of 82%pred (68-95). According to anatomic extent of BE on HRCT; 2 patients had mild, 4 had moderate and 21 had severe BE. Based on severity scores of HRCT; 10 patients had mild, 10 had moderate and 7 had severe BE. Neutrophils consisted 29.9% (14.9-53.7) of the total leucocytes in induced sputum samples. Sputum concentration of TNF-alpha was 58 pg/ml (9.2-302) while IL-8 concentration was 2.7 ng/ml (1.7-2.8). Symptom scores correlated with FEV(1) and sputum IL-8 levels (r=-0.49, r=0.67, P<0.05). There was a significant correlation between HRCT severity scores and symptoms, FEV(1), sputum IL-8 and TNF-alpha levels (r=0.64, r=-0.68, r=0.41, r=0.41, respectively, P<0.05). In children BE is associated with ongoing inflammation. This inflammation can be reliably monitored by radiological scores, spirometry, as well as sputum inflammatory markers. Follow-up of children with BE using these clinical tools may improve patient care.

Computed tomography and cystic fibrosis: promises and problems

Computed tomography (CT) has two potential roles in the evaluation of patients with cystic fibrosis (CF) lung disease: as a diagnostic test primarily for the detection of supervening complications and as a monitoring tool in clinical research. Interest in the latter role has gained momentum in the last 5 years because of two factors: (1) therapeutic options for CF lung disease are developing rapidly, hence the need for an outcome measure that can be applied in clinical intervention trials; and (2) it has become clear that traditional outcome measures such as pulmonary function tests are relatively insensitive to the early structural damage that occurs in CF. Several recent studies have shown that CT can be used as a potential surrogate outcome measure, although its suitability for this specific role is controversial and still under investigation. This review summarises current concepts relating to the research applications of CT in CF, with particular emphasis on the evidence supporting the use of CT as a surrogate outcome measure in clinical trials.

Outcome in adult bronchiectasis

The outcome in adult bronchiectasis has not been well described; in particular there has been a lack of long-term prospective studies. Therefore a follow-up study was performed to assess outcome in bronchiectasis in a cohort of adult patients. One hundred-and-one sequential adults, 33 male and 68 female; age 54 +/- 14 years (mean +/- SD) with bronchiectasis had a clinical assessment and spirometry performed. All were non-smokers and 84 were classified as having idiopathic disease. Patients were commenced on a standardized treatment regime and followed up for a minimum period of 2 years. On their last review when patients were clinically stable, a repeat clinical assessment and spirometry was performed and compared with the initial review. The primary endpoints measured were symptoms and FEV1. Subjects were followed up for 8.0 +/- 4.9 years. Clinical review showed that the patients had persistent symptoms that, in the case of dyspnea and sputum volume, were worse on follow-up. Spirometry showed a significant decline in FEV1 over the follow-up period with an average loss of 49 ml per year. This study showed in this group of predominantly female adult patients with bronchiectasis followed up for 8 years, patients had persistent symptoms and an excess loss in FEV1.

Bronchiectasis: correlation of high-resolution CT findings with health-related quality of life

AIM

To evaluate the relationship between the severity of bronchiectatic diseases, as evident on high-resolution computed tomography (HRCT) and the patient's quality of life measured using the St George's Respiratory Questionnaire (SGRQ).

METHODS AND MATERIALS

Forty-six patients (25 women, 21 men, mean age: 63 years) with bronchiectatic disease as evident on recent HRCT examinations were recruited. Each patient completed the SGRQ and underwent respiratory function tests. HRCT findings were blindly and independently scored by two radiologists, using the modified Bhalla scoring system. The relationships between HRCT scores, SGRQ scores and pulmonary function tests were evaluated.

RESULTS

The patients' total CT score did not correlate with the SGRQ scores. However, patients with more advanced disease on HRCT, significantly differed in their SGRQ scores from patients with milder bronchiectatic disease. A significant correlation was found between the CT scores for the middle and distal lung zones and the activity, impacts and total SGRQ scores. No correlation was found between CT scores and respiratory function test indices. However, a significant correlation was found between the SGRQ scores and most of the respiratory function test indices.

CONCLUSION

A correlation between the severity of bronchiectatic disease as expressed in HRCT and the health-related quality of life exists in patients with a more severe bronchiectatic disease but not in patients with mild disease. Such correlation depends on the location of the bronchiectasis in the pulmonary tree.

Fully automated system for three-dimensional bronchial morphology analysis using volumetric multidetector computed tomography of the chest

Recent advancements in computed tomography (CT) have enabled quantitative assessment of severity and progression of large airway damage in chronic pulmonary disease. The advent of fast multidetector computed tomography scanning has allowed the acquisition of rapid, low-dose 3D volumetric pulmonary scans that depict the bronchial tree in great detail. Volumetric CT allows quantitative indices of bronchial airway morphology to be calculated, including airway diameters, wall thicknesses, wall area, airway segment lengths, airway taper indices, and airway branching patterns. However, the complexity and size of the bronchial tree render manual measurement methods impractical and inaccurate. We have developed an integrated software package utilizing a new measurement algorithm termed mirror-image Gaussian fit that enables the user to perform automated bronchial segmentation, measurement, and database archiving of the bronchial morphology in high resolution and volumetric CT scans and also allows 3D localization, visualization, and registration.

Kartagener syndrome

Kartagener syndrome (KS), an autosomal recessively inherited disease, is characterized by the triad of situs inversus, bronchiectasis and sinusitis. This disorder affects the activity of proteins important to the movement of cilia, especially in the respiratory tract and the spermatozoa, developing a series of systemic alterations, which can be diagnosed through radiographic examination. The aim of this paper is to describe a clinical case of this unusual pathology, including a brief literature review, emphasising the radiographic aspects of this pathology and stressing the importance of early diagnosis, which could be determined by an oral radiologist.

Conventional High-Resolution CT Versus Helical High-Resolution MDCT in the Detection of Bronchiectasis

OBJECTIVE

The purpose of this study was to compare conventional high-resolution CT (HRCT) with helical 16-MDCT in the detection of bronchiectasis.

MATERIALS AND METHODS

We retrospectively evaluated 80 patients including 61 with bronchiectasis (mean age, 64 years; range, 22-87 years) and a control group of 19 patients with normal MDCT of the chest. Two sets of images were blindly, randomly analyzed by two observers: contiguous 1-mm slices (MDCT set) and 1-mm slices every 10 mm (HRCT set) derived from the MDCT set. Images were scored independently for presence, extent, and severity of bronchiectasis, followed by a consensus interpretation. Kappa analysis assessed inter- and intraobserver agreement. MDCT was the radiologic gold standard.

RESULTS

Of the 61 patients with bronchiectasis diagnosed with MDCT, 56 (92%) were positive for bronchiectasis on conventional HRCT. Seven patients had positive MDCT scans only, and two patients had positive HRCT scans only. Of 479 lobes, 59 were positive for bronchiectasis on MDCT and negative on HRCT, and 19 lobes were positive for bronchiectasis on HRCT and negative on MDCT (p < 0.0001). MDCT showed 25 more lobes with cylindric, 11 more lobes with varicose, and four more lobes with cystic bronchiectasis than did HRCT. Sensitivity, specificity, and positive and negative predictive values of HRCT in detecting bronchiectasis were 71%, 93%, 88%, and 81%, respectively. Interobserver agreement for presence, extent, and severity of bronchiectasis ranged from moderate to good for MDCT (kappa values, 0.64, 0.5, and 0.48, respectively) and poor to good for HRCT (kappa values, 0.65, 0.46, and 0.25, respectively).

CONCLUSION

Contiguous helical 16-MDCT with 1-mm collimation is superior to HRCT at 10-mm intervals in showing the presence and extent of bronchiectasis.

Assessing immune function in adult bronchiectasis

Bronchiectasis is characterized by chronic airway infection and damage and remains an important health problem. Recent literature has emphasized the role of host defence and immune deficiency in the pathogenesis of bronchiectasis, but there have been few studies of immune function in adult bronchiectasis. A comprehensive screen of immune function was conducted in 103 adult patients with bronchiectasis, encompassing full blood examinations, immunoglobulins and IgG isotypes, complement levels, lymphocyte subsets and neutrophil function. Full blood examinations were normal in this cohort, as were complement levels. Statistical analysis confirmed that a significant number of subjects had low levels of IgG3 (13 patients), B cell lymphocytes (six patients) and T helper cell lymphocytes (seven patients) when compared with controls (P<0.05). The most common abnormality was found with testing of the neutrophil oxidative burst. All subjects had a normal neutrophil phagocytic function but 33 of the subjects had an oxidative burst that was below the normal range (P<0001). Almost half the group (45 subjects) had abnormally low levels of one of these four parameters. The findings of low B cells, Th cells and oxidative burst in bronchiectasis are novel. The results emphasize the importance of immune function assessment for adult bronchiectasis.

Excessive Collapsibility of Bronchi in Bronchiectasis

OBJECTIVE

To evaluate the frequency and severity of bronchomalacia, defined as excessive collapsibility of bronchi, in bronchiectasis; to compare the extent of air trapping in bronchiectasis patients with/without bronchomalacia; and to correlate the severity of bronchomalacia and the extent of air trapping versus pulmonary function.

MATERIALS AND METHODS

Forty-six patients with bronchiectasis evaluated by volumetric expiratory high-resolution computed tomography (CT) and pulmonary function tests were studied. The presence and severity of bronchomalacia were evaluated on contiguous axial high-resolution CT images using a 4-point scale. The extent of air trapping was graded on coronal reformations using a 5-point scale. Differences in the extent of air trapping in patients with/without bronchomalacia and the correlation between the severity of bronchomalacia and the extent of air trapping were investigated. The severity of bronchomalacia and the extent of air trapping were correlated with pulmonary function.

RESULTS

Of 46 patients with bronchiectasis, 32 patients (70%) had bronchomalacia. Air trapping was present in 43 patients (93%). The extent of air trapping in patients with bronchomalacia was significantly greater compared with the patients without bronchomalacia (P=0.0308). The correlation between the severity of bronchomalacia and extent of air trapping was not statistically significant (rs=0.029, P=0.8457).

CONCLUSIONS

The extent of air trapping in bronchiectasis patients with bronchomalacia was significantly greater compared with bronchiectasis patients without bronchomalacia, suggesting that the bronchomalacia is one of the underlying mechanisms of air trapping in bronchiectasis.

Loss of anteroposterior intralobar attenuation gradient of the lung: Correlation with pulmonary function

RATIONALE AND OBJECTIVES

Since the initial description of an intralobar attenuation gradient by Webb et al, it has been suggested that departure from the intralobar attenuation gradient could indicate early lung diseases. However, its significance has not been determined in detail. We aimed to quantify the anteroposterior intralobar attenuation gradient on volumetric end-inspiratory and end-expiratory high-resolution computed tomography (CT) in patients with emphysema and to correlate the gradient values with pulmonary function.

MATERIALS AND METHODS

The study population consisted of 21 consecutive patients with emphysema evaluated with volumetric expiratory high-resolution CT and 6 patients with normal high-resolution CT findings. The anteroposterior intralobar attenuation gradient values were quantified on end-inspiratory and end-expiratory sagittal reformations using a lung analysis software program and were correlated with pulmonary function tests results.

RESULTS

The intralobar attenuation gradient values in patients with forced expiratory volume in 1 second (FEV1) < or =70% were significantly smaller compared with those in patients with FEV1 >70% in bilateral lower lobes at end-expiration (P = .0061, P = .047, respectively, unpaired t-test). The FEV1 values in patients with attenuation gradient values < or =0.02 were significantly lower than in those with attenuation gradient values >0.02 (right lower lobe: P = .024; left lower lobe: P = .0034; chi-squared test). The intralobar attenuation gradient values in bilateral lower lobes at end-expiration were significantly correlated with FEV1 and FEV1/forced vital capacity (right: P = .031, P = .039, respectively; left: P = .036, P = .030, respectively, Pearson correlation).

CONCLUSIONS

The quantitative measurement of the anteroposterior intralobar attenuation gradient values of the lung showed that these gradients at end-expiration in both lower lobes correlate with obstructive physiology.

Alpha-1 antitrypsin deficiency and computed tomography findings

OBJECTIVE

To investigate the severity of bronchiectasis and associated emphysema and the correlation with phenotype in patients with Alpha-1 antitrypsin deficiency.

METHODS

The scoring system of Ooi and his colleagues for bronchiectasis was modified to include the degree of dilatation of bronchi in affected segments and degree of emphysema. This was applied to 26 high-resolution computed tomography thorax scans of the study population. All criteria were scored on a scale of 0-3.

RESULTS

Nine patients (35%) were female and 17 (65%) were male. The median age was 56 years (range: 17-76 years). Twenty-one patients had a ZZ phenotype, 3 patients had an MZ phenotype, and 2 patients had an SZ phenotype. The median forced expiratory volume in 1 second/forced vital capacity ratio was 43% (range: 24%-87%). A total of 156 lobes were assessed, and 38 (24%) had evidence of bronchiectasis. The overall median total score in affected patients for the extent of bronchiectasis was 2, and all had a ZZ phenotype. Fourteen patients (54%) had a degree of dilatation score of 1 or more, all had a ZZ phenotype, and 4 (15%) had no evidence of emphysema. Bronchiectasis was seen most commonly affecting the upper lobes.

CONCLUSION

The ZZ phenotype was associated with bronchiectasis most commonly affecting the upper lobes, with moderate emphysema throughout all lobes. Numbers of patients having the SZ and MZ phenotypes are too small to derive accurate conclusions, but none had evidence of bronchiectasis.

Do High-Resolution CT Findings of Usual Interstitial Pneumonitis Obviate Lung Biopsy?

BACKGROUND

High-resolution CT (HRCT) of the lungs has become an essential component to evaluate patients with diffuse lung disease. Little is known, however, about the current practices of pulmonologists caring for patients with these complex conditions, and, in particular, whether HRCT can obviate the need for surgical lung biopsy.

OBJECTIVES

To investigate the practices of pulmonologists concerning the acceptability of a HRCT diagnosis in lieu of lung biopsy in diffuse lung disease.

METHODS

We asked practicing pulmonologists among membership of the American College of Chest Physicians whether HRCT results could replace lung biopsy in 16 diffuse lung diseases. Responses were examined in light of published evidence, practice guidelines, and certain practice parameters.

RESULTS

Two hundred and thirty (52.6%) of 437 eligible physicians responded. Sixty-seven percent (67%) of respondents accepted HRCT diagnosis for idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP) despite their awareness of guidelines recommending histological diagnosis. Most would not accept a radiologic diagnosis for lymphangioleiomyomatosis (LAM; 37%) or eosinophilic granuloma (Langerhans' cell histiocytosis, LCH; 19%), even though CT findings are frequently characteristic. Responses were similar by type of clinical practice and recency of fellowship training. Chest physicians who referred patients for HRCT more frequently were more likely to accept HRCT diagnosis (p=0.008) and those who had higher self-ratings of proficiency in reading HRCT (p = 0.004) were more likely to believe HRCT often suggests specific diagnosis.

CONCLUSIONS

Most US pulmonologists will accept an HRCT diagnosis of IPF/UIP without lung biopsy, but are reluctant to do so for most other diffuse lung conditions including LAM and LCH.

Relationships between high-resolution computed tomography, lung function and bacteriology in stable bronchiectasis

To determine the relationship between high-resolution computed tomography (HRCT) findings, lung function, and bacteriology in bronchiectasis, we conducted a retrospective study of 49 Korean patients with stable bronchiectasis. To quantify the extent and severity of bronchiectasis, we used a CT scoring system consisting of bronchial dilatation, bronchial wall thickening, the number of bronchiectatic segments, the number of bulla, and the number of emphysema segments. The presence of air-fluid levels and lung consolidation were also evaluated. The results of CT scoring, spirometry and sputum culture were analyzed. Patients with cystic bronchiectasis had higher CT score, more dilated lumen and lower forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1/FVC than patients with cylindrical bronchiectasis. Patients with mixed ventilatory impairment had larger number of bronchiectatic segments than patients with obstructive ventilatory impairment. CT score and the number of bronchiectatic segments were significantly associated with FVC and FEV1, while CT score and the number of emphysema segments were significantly associated with FEV1/FVC. Twenty-one patients of 49 patients showed a positive sputum culture including 15 cases of Pseudomonas aeruginosa. The CT score was the most important predictor of lung function. The presence of air-fluid levels predicted bacterial colonization.

β-Thalassemia Major: Thin-Section CT Features and Correlation with Pulmonary Function and Iron Overload

PURPOSE

To describe and quantify thin-section computed tomographic (CT) features of the lung in patients with beta-thalassemia major (beta-TM) and determine the correlation between thin-section CT findings, pulmonary function test (PFT) results, and iron overload.

MATERIALS AND METHODS

Forty-one patients with beta-TM (mean age, 24.5 years) underwent thin-section CT (during full inspiration and expiration) and PFTs. Two radiologists in consensus recorded the presence of focal bronchial and parenchymal abnormalities and air trapping. A semiquantitative air trapping score (ATS) was used, and patients were separated into air trapping-negative (ATS between 0 and 3) and air trapping-positive (ATS > 3) groups for statistical analysis. Iron overload was estimated by calculating the ratio of the signal intensity (SI) of the liver to the SI of paraspinous muscle by using magnetic resonance imaging in 27 patients (66%). We performed multiple logistic regression analysis to study the influence of age, PFT findings, and SI ratio on the presence of air trapping at CT and multivariate regression analysis to study the simultaneous influence of the presence of air trapping on obstructive PFT indexes.

RESULTS

Air trapping was the predominant thin-section CT finding and was seen in 10 (24%) of 41 patients. No patient had interstitial lung disease at CT, although 11 (27%) had a restrictive spirometric pattern. Simple logistic regression analysis revealed significant associations between ATS and forced expiratory volume in the first second (FEV1), FEV1/forced vital capacity (FVC), forced expiratory flow (FEF) in the midexpiratory phase (FEF25%-75%), FEF at 50% of the FVC (FEF50%), and FEF at 75% of the FVC (FEF75%) (P =.019,.030,.007,.034, and.021, respectively) but not between ATS and SI ratio. At multiple logistic regression analysis, only FEF25%-75% was significantly associated with ATS (P =.019, adjusted odds ratio = 0.86, R2 = 41.8%). Multivariate analysis revealed that ATS did not have a significant influence on lung function indexes (P =.104), although significant effects were found with FEV1, FEF25%-75%, FEF50%, and FEF75% when examined separately.

CONCLUSION

Air trapping may be present at expiratory thin-section CT in patients with beta-TM and is associated with reduced FEF25%-75% values but not hepatic iron overload.