High-resolution computed tomography findings from adult patients with Influenza A (H1N1) virus-associated pneumonia

Objective

The aim of this study was to assess the high-resolution computed tomography (HRCT) findings at presentation in patients diagnosed with Influenza A (H1N1) virus-associated pneumonia.

Materials and methods

We reviewed the HRCT findings from 20 patients diagnosed with Influenza A (H1N1) and compared their HRCT scans with chest radiographs, obtained on the same day. The imaging studies were obtained 4-9 days after the onset of symptoms. The patients included 11 men and 9 women (ages 24-62 years; mean 42.7 years). All patients had a body temperature greater than 100.4 °F (>38 °C), tachypnea, and cough. Other common symptoms included diarrhea (60%) and sore throat (30%). The radiographs and HRCT scans were reviewed independently by two observers who reached a consensus decision.

Results

The predominant HRCT findings consisted of bilateral ground-glass opacities (n = 12), bilateral areas of consolidation (n = 2), or a mixed bilateral pattern of ground-glass opacities and areas of consolidation (n = 6). The abnormalities were bilateral in all of the 20 patients, had a predominantly sub-pleural distribution in 13 patients, and had a random distribution in the remaining 7 patients. The predominant radiographic findings were consolidations. Normal radiographs were found in 4 out of the 20 patients.

Conclusion

HRCT may reveal parenchymal abnormalities in patients with Influenza A (H1N1) infection who have normal findings on radiographs. The predominant HRCT findings were bilateral, peripheral, ground-glass opacities and/or bilateral areas of consolidation. The patients who presented consolidations had more severe clinical course.     

Herpes-Simplex-Virus 1 pneumonia in the immunocompromised host: high-resolution CT patterns in correlation to outcome and follow-up

Objective

To identify the high-resolution CT (HRCT) patterns of Herpes-Simplex-Virus 1 (HSV) pneumonia in immunocompromised patients and correlate findings to outcome and radiographic follow-up until death or complete resolution of findings.

Patients and methods

HRCT data-sets and plain radiographic follow-ups were reviewed in 25 immunocompromised patients with confirmation of new onset HSV-1 pneumonia. Pattern and distribution of abnormalities was assessed by two chest radiologists and findings evaluated regarding outcome and dynamics.

Results

The most frequent CT abnormalities included ground-glass attenuation (n = 18; 72%) in a bilateral, symmetric and random distribution, air-space consolidations (n = 13; 52%) in a bilateral, asymmetric and peribronchial allocation and interlobular septal thickening (n = 6; 24%).When classified by leading HRCT pattern, patients subdivided into distinct groups with either dominant ground-glass attenuation or air-space consolidation. Six patients died after a median 8 days of diagnosis; the median interval until complete radiographic remission of pathology was 20 days. Pre-dominance of air-space consolidations was associated with significant delay of improvement (p = 0.023); however, patient outcome was comparable in both subgroups (p = 0.9).

Conclusion

Diagnosis of HSV pneumonia is challenging and requires familiarity with two distinct HRCT patterns: predominance of ground-glass opacities or air-space consolidations. Whilst the two forms are not linked to patient outcome they demonstrate a variable dynamic at follow-up.     

Serial evaluation of high-resolution CT findings in patients with pneumonia in novel swine-origin influenza A (H1N1) virus infection

Objectives

The purpose of our study was to review the changes in the serial high-resolution CT (HRCT) findings from patients with novel swine-origin influenza A (H1N1) virus (S-OIV) infection.

Methods

HRCT findings of 70 patients with presumed or laboratory-confirmed novel S-OIV infection were reviewed. The pattern (consolidation, ground glass, fibrosis and air trapping), distribution and extent of abnormality of the lesions on the HRCT were evaluated at different time points. To assess changes that occurred over time, the CT scans in 56 patients were examined in sequence.

Results

The most common CT findings in patients with S-OIV infection are ground-glass opacities with or without consolidation at the first week. The abnormalities peaked at the second week and resolved after that time, which resulted in substantial reduced residual disease at 4 weeks or later. The development of fibrosis was noted in the first week and peaked at the third week of illness (34.7%), then decreased slowly after that time. The mean time of air trapping being noted after the onset of symptoms was 55.5±20.6 days. Comparing the findings of initial CT, most results (96.4%) of follow-up chest CT findings showed improvement (p<0.01).

Conclusion

The abnormalities of ground-glass opacities and/or consolidation on initial CT scans tended to resolve to fibrosis, which then resolved completely or displayed substantially reduced residual disease. HRCT may show more changes in disease progression and play an important role in the evaluation of severe S-OIV.A novel swine-origin influenza A (H1N1) virus (S-OIV) was first reported in Mexico and became rampant globally later on in spring 2009 [1]. The World Health Organization declared the first Phase 6 global influenza pandemic of the century on 11 June 2009 [2]. During peak periods of influenza in autumn to winter of that year, a proportion of patients developed severe acute respiratory distress syndrome (ARDS), and some died of the disease. Serial chest radiography has been the main technique in the initial investigation of patients with suspected H1N1. However, multislice CT (MSCT) scanning is more sensitive than chest radiography, providing more detailed radiological features. Previous studies have reported that the predominant CT findings of disease were unilateral or bilateral multifocal peribronchovascular and/or subpleural ground-glass opacities (GGOs) with or without consolidation [1,3]. Little is known, however, about sequential MSCT findings during the subsequent course of pneumonia with H1N1. The purpose of this study was to evaluate the radiological changes on serial thin-section chest CT scans in patients with H1N1 during the acute and convalescent periods of the illness.     

High-resolution computed tomographic findings of Aspergillus infection in lung transplant patients

Objective

The aim of this study was to assess high-resolution computed tomographic (HRCT) findings at presentation in lung transplant patients diagnosed with pulmonary Aspergillus infection.

Materials and methods

We retrospectively reviewed HRCT findings from 23 patients diagnosed with pulmonary aspergillosis. Imaging studies were performed 2–5 days after the onset of symptoms. The patient sample comprised 12 men and 11 women aged 22–59 years (mean age, 43.6 years). All patients had dyspnea, tachypnea, and cough. Diagnoses were established with Platelia Aspergillus enzyme immunoassays for galactomannan antigen detection in bronchoalveolar lavage and recovery of symptoms, and HRCT findings after voriconazole treatment. The HRCT scans were reviewed independently by two observers who reached a consensus decision.

Results

The main HRCT pattern, found in 65% (n = 15) of patients, was centrilobular tree-in-bud nodules associated with bronchial thickening. This pattern was described in association with areas of consolidation and ground-glass opacities in 13% (n = 3) of patients. Consolidation and ground-glass opacities were the main pattern in 22% (n = 5) of patients. The pattern of large nodules with and without the halo sign was observed in 13% (n = 3) of patients, and were associated with consolidation and ground-glass opacities in one case.

Conclusion

The predominant HRCT findings in lung transplant patients with pulmonary aspergillosis were bilateral bronchial wall thickening and centrilobular opacities with the tree-in-bud pattern. Ground-glass opacities and/or bilateral areas of consolidation were also common findings. Pulmonary nodules with the halo sign were found in only 13% of patients.     

Herpes simplex virus pneumonia: high-resolution CT findings

The purpose of this study was to evaluate the high-resolution computed tomographic (HRCT) findings of five adult patients (either immunocompromised or immunocompetent) with herpes simplex virus (HSV) pneumonia. We retrospectively assessed HRCT images of 5 patients (all male patients, age range 39–70 years; mean 62 years) with HSV pneumonia. The specific pathological findings that allowed for a definite diagnosis of HSV pneumonia included the presence of intranuclear inclusion bodies on haematoxylin and eosin staining, or positive immunohistochemical staining. High-resolution CT scans (HiSpeed Advantage or LightSpeed QX/i, GE Healthcare) using 1- or 1.25-mm collimation at 10-mm intervals without intravenous contrast medium injection were assessed, in particular for the presence and distribution of parenchymal abnormalities including ground-glass attenuation, airspace consolidation, nodules and interlobular septal thickening. In two patients, pathological specimens were obtained from open lung biopsy or bronchoscopic biopsy, and were correlated with HRCT findings. Three HRCT patterns of pulmonary abnormalities were identified in our series of HSV pneumonia: predominant areas of diffuse or multifocal ground-glass attenuation, predominant areas of multifocal peribronchial consolidations, and a mixed pattern of both. Histopathologically, areas of ground-glass attenuation seen on HRCT corresponded to diffuse alveolar damage in one patient who underwent open lung biopsy. No specific differences in HRCT findings were seen between the immunocompromised and the immunocompetent patients. In patients suspected of having an acute lower respiratory infection, whether immunocompromised or immunocompetent, a possibility of HSV pneumonia can be included in differential diagnoses when diffuse or multifocal areas of ground-glass attenuation and/or consolidations are seen on HRCT.Herpes simplex virus (HSV) pneumonia can occur in patients with complications of immunosuppression, airway injury from intubation or smoke inhalation [1, 2]. Pathologically, HSV infection can have three main forms of pulmonary involvement: necrotising tracheobronchitis, necrotising pneumonia and interstitial pneumonitis [3]. The interstitial pneumonitis form of HSV pulmonary infection is characterised by diffuse alveolar damage consisting of interstitial lymphocytic infiltration, alveolar haemorrhage and hyaline membrane formation [4].A few reports have previously described the high-resolution CT (HRCT) findings of HSV pneumonia in immunocompromised patients [1, 2], including areas of ground-glass attenuation, airspace consolidation and small centrilobular nodules.The purpose of this study was to evaluate the HRCT findings of five adult patients (either immunocompromised or immunocompetent) with HSV pneumonia.     

Paracoccidioidomycosis: High-resolution computed tomography-pathologic correlation

Objective

The purpose of this study was to describe the high-resolution computed tomography (HRCT) features of pulmonary paracoccidioidomycosis and to correlate them with pathologic findings.

Methods

The study included 23 adult patients with pulmonary paracoccidioidomycosis. All patients had undergone HRCT, and the images were retrospectively analyzed by two chest radiologists, who reached decisions by consensus. An experienced lung pathologist reviewed all pathological specimens. The HRCT findings were correlated with histopathologic data.

Results

The predominant HRCT findings included areas of ground-glass opacities, nodules, interlobular septal thickening, airspace consolidation, cavitation, and fibrosis. The main pathological features consisted of alveolar and interlobular septal inflammatory infiltration, granulomas, alveolar exudate, cavitation secondary to necrosis, and fibrosis.

Conclusion

Paracoccidioidomycosis can present different tomography patterns, which can involve both the interstitium and the airspace. These abnormalities can be pathologically correlated with inflammatory infiltration, granulomatous reaction, and fibrosis.     

Exogenous lipoid pneumonia: high-resolution CT findings

The aim of this study was to assess high-resolution computed tomography (HRCT) findings of exogenous lipoid pneumonia. High-resolution computed tomography was obtained in 25 patients with proven exogenous lipoid pneumonia resulting from aspiration of squalene (derived from shark liver oil). Diagnosis was based on biopsy (n = 9), bronchoalveolar lavage (n = 8), or sputum cytology and clinical findings (n = 8). The clinical history of taking squalene was confirmed in all patients. The CT findings were classified into three patterns: diffuse ground-glass opacity, consolidation, and interstitial abnormalities. Distribution of the abnormalities, duration of taking squalene, predisposing factors for aspiration, and route of administration were analyzed. Ten patients showed diffuse ground-glass opacity pattern. Seven of 10 patients had predisposing conditions such as unconsciousness, pharyngeal dysmotility, or motor disturbances, and 6 patients had a recent history of taking large amount of squalene through nasal route. Seven patients who had consolidation pattern had a history of taking squalene for several months and did not have any predisposing factor. All of the 5 patients who had a pattern of interstitial abnormalities had a history of taking squalene longer than 1 year and showed segmental distribution of interstitial thickening with interposing ground-glass opacities. Three patients simultaneously had two different patterns at different lobes of the lung. The HRCT findings of lipoid pneumonia are ground-glass opacities, consolidation, and interstitial abnormalities. These HRCT findings with appropriate inquiries could be useful for diagnosis of exogeneous lipoid pneumonia. Received: 12 September 1997; Revision received: 13 February 1998; Accepted: 7 April 1998     

H1N1 pneumonia: our experience in 50 patients with a severe clinical course of novel swine-origin influenza A (H1N1) virus (S-OIV)

Purpose

The authors reviewed chest radiographs (CXR) and thin-section computed tomography (CT) findings of pulmonary complications in a selected population of 50 consecutive patients with severe novel swine-origin influenza A (H1N1) virus (S-OIV) pneumonia who were seen at the Subintensive Respiratory Unit (UTSIR) and at the Intensive Care Unit (ICU) at Monaldi Hospital, Naples, Italy.

Materials and methods

CXR and CT findings of 50 patients who fulfilled the World Health Organisation (WHO) criteria for S-OIV infection were reviewed by four radiologists. The final study group of 50 patients was divided into two subgroups on the basis of clinical course: group 1 consisted of 42 patients requiring noninvasive mechanical ventilation and admitted to the UTSIR; group 2 consisted of eight patients who required ICU admission and extracorporeal membrane oxygenation or advanced mechanical ventilation from October 2009 to December 2009. All patients underwent CXR and thinsection multidetector CT (MDCT) scan; the initial and follow-up radiographs and CT scans were evaluated for the presentation and follow-up pattern (consolidation, groundglass opacities, nodules, reticulation), distribution and extent of abnormality.

Results

All patients had radiological signs of pulmonary involvement. Ground-glass opacity and consolidation, which was mainly peripheral, was the most frequent finding. In three patients, we report for the first time in viral pneumonia the reversed halo sign. Lesion extent was related to aggressiveness of the illness. More often, both lungs were involved (82%). Thoracic comorbidity was present in 18% of patients; 22% of patients was obese, and in this group, the clinical course was more aggressive than in the others with the same lesion extent at imaging. Furthermore, superinfection led to worsening of the clinical conditions.

Conclusions

The most common CXR and CT findings in patients with S-OIV infection were unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On MDCT, ground-glass opacities and areas of consolidation had a predominant peribronchovascular and subpleural distribution, resembling organising pneumonia; they progressed to bilateral extensive airspace disease in severely ill patients.     

Comparison of initial high resolution computed tomography features in viral pneumonia between metapneumovirus infection and severe acute respiratory syndrome

Objective

To review and compare initial high resolution computed tomography (HRCT) findings in patients with metapneumovirus pneumonia and severe acute respiratory syndrome (SARS-Coronovirus).

Materials and methods

4 cases of metapneumovirus pneumonia (mean age of 52.3 years) in an institutional outbreak (Castle Peak Hospital) in 2008 and 38 cases of SARS-coronovirus (mean age of 39.6 years) admitted to Tuen Mun hospital during an epidemic outbreak in 2003 were included. HRCT findings of the lungs for all patients were retrospectively reviewed by two independent radiologists.

Results

In the metapneumovirus group, common HRCT features were ground glass opacities (100%), consolidation (100%), parenchymal band (100%), bronchiectasis (75%). Crazy paving pattern was absent. They were predominantly subpleural and basal in location and bilateral involvement was observed in 50% of patients. In the SARS group, common HRCT features were ground glass opacities (92.1%), interlobular septal thickening (86.8%), crazy paving pattern (73.7%) and consolidation (68%). Bronchiectasis was not seen. Majority of patient demonstrated segmental or lobar in distribution and bilateral involvement was observed in 44.7% of patients. Pleural effusion and lymphadenopathy were of consistent rare features in both groups.

Conclusion

Ground glass opacities, interlobular septal thickening and consolidations were consistent HRCT manifestations in both metapneumovirus infection and SARS. The presence of bronchiectasis (0% in SARS) may point towards metapneumovirus while crazy paving pattern is more suggestive of SARS.     

Chronic interstitial pneumonia in young patients undergoing lung transplantation or autopsy: clinico-radiologic-pathologic observations from a single institution

Purpose

To retrospectively evaluate high-resolution computed tomography (HRCT) findings and clinical diagnoses of chronic interstitial pneumonia (IP) with a poor prognosis in young patients (≤50 years).

Materials and methods

HRCT images of 8 men and 7 women (mean age 34.8 years) obtained before lung transplantation or autopsy were reviewed. After reviewing whole lung specimens and pathologic diagnoses, all patients were clinically diagnosed according to the 2010 idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP) consensus statement.

Results

HRCT images revealed intralobular reticular opacity, air cysts, ground glass opacity, traction bronchiectasis, and interlobular septal thickening. Intralobular reticular opacity was the most extensive finding. Abnormal findings existed predominantly in both the peripheral and lower lung zones in only 1 patient. Classifications of HRCT patterns were “UIP” (n = 2), “inconsistent with UIP” (n = 11), and “indeterminate UIP” (n = 2). Multidisciplinary diagnoses were “IPF/UIP” (n = 1), “possible IPF/UIP” (n = 1), “IP with connective tissue disease” (n = 7), “fibrotic nonspecific IP” (n = 1), and “unclassified IP” (n = 5).

Conclusion

The most extensive HRCT finding was intralobular reticular opacity. Most HRCT images differed from typical IPF/UIP, and IPF/UIP was uncommon in young patients with chronic IP with a poor prognosis.

     

Nonspecific interstitial pneumonia: histologic correlation with high-resolution CT in 29 patients

Purpose

To determine the pathological correlation with various high-resolution CT (HRCT) findings in cases with nonspecific interstitial pneumonia (NSIP), paying special attention to pathological subgroups.

Material and methods

The study involved 29 patients diagnosed with NSIP by surgical lung biopsy. A total of 54 specimens were obtained and grouped according to Katzenstein's classification (groups 1–3) for NSIP. Two observers then evaluated the HRCT findings for every biopsy site and classified the findings according to the main pattern evident into the following four radiologic pattern groups: A, ground-glass attenuation and fine reticulation; B, ground-glass and coarse reticulation; C, consolidation and D, ground-glass attenuation and consolidation.

Results

The pathological pattern was NSIP group 1 in 6 patients, group 2 in 22 and group 3 in 25, while 1 specimen was normal. The main HRCT pattern was pattern A in 15 specimens, B in 8, C in 9 and D in 21. Although there were no significant correlation between HRCT patterns and histological subgroups (Chi-square test, p = 0.07), pattern C was more frequently seen in group 2 (7 of 9) and pattern A was more common in group 3 (11 of 15). HRCT pattern A corresponded pathologically to areas of thickened alveolar septa with temporal uniformity. Pattern B correlated with areas with airspace enlargement/emphysema or dilation of small airways superimposed on thickened alveolar septa. Pattern C was pathologically associated with areas of severe thickened alveolar septa, mucin stasis in the small airways and intraluminal organization.

Conclusion

The pathological backgrounds of the same CT findings in patients with NSIP varied among all pathological subgroups. Areas of ground-glass attenuation and air-space consolidation did not always correspond to reversible pathological findings.     

Computed tomographic features of 23 sporadic cases with Legionella pneumophila pneumonia

Objective

To describe the chest computed tomographic (CT) findings of Legionella pneumophila pneumonia.

Methods

CT scans obtained from 23 sporadic cases of L. pneumophila pneumonia were retrospectively reviewed. Chest CT findings were analyzed with regard to the patterns and distributions of pulmonary abnormalities. We also analyzed the histopathology of lungs from guinea pigs with experimentally induced L. pneumophila pneumonia.

Results

Consolidation and ground-glass opacity (GGO) were the main findings of CT scans in L. pneumophila pneumonia. The distribution of opacities was categorized as non-segmental (n = 20) and segmental (n = 4). Non-segmental distribution may follow an onset of segmental distribution. Pleural effusion was observed in 14 (58.3%) patients, of which 13 were accompanied with non-segmental distribution. Abscess formation was observed in only one immunocompromised patient. In the animal pneumonia model, the lesions comprised of terminal bronchioles, alveolar spaces, and interstitia. Small bacilli were observed to be contained by many macrophages within the alveoli.

Conclusion

Non-segmental distribution was significantly more frequent than segmental distribution in L. pneumophila pneumonia. It is possible that L. pneumophila infection initially results in segmental pneumonia, which progresses to typical non-segmental distribution.     

Cytomegalovirus Pneumonia: High-Resolution CT Findings in Ten Non-AIDS Immunocompromised Patients

Objective

To describe the HRCT findings of cytomegalovirus (CMV) pneumonia in non-AIDS immunocompromised patients.

Materials and Methods

This retrospective study involved the ten all non-AIDS immunocompromised patients with biopsy-proven CMV pneumonia and without other pulmonary infection encountered at our Medical Center between January 1997 and May 1999. HRCT scans were retrospectively analysed by two chest radiologists and decisions regarding the findings were reached by consensus.

Results

The most frequent CT pattern was ground-glass opacity, seen in all patients, with bilateral patchy (n = 8) and diffuse (n = 2) distribution. Other findings included poorly-defined small nodules (n = 9) and consolidation (n = 7). There was no zonal predominance. The small nodules, bilateral in eight cases and unilateral in one, were all located in the centrilobular region. Consolidation (n = 7), with patchy distribution, was bilateral in five of seven patients (71%). Pleural effusion and bilateral areas of thickened interlobular septa were seen in six patients (60%).

Conclusion

CMV pneumonia in non-AIDS immunocompromised patients appears on HRCT scans as bilateral mixed areas of ground-glass opacity, poorly-defined centrilobular small nodules, and consolidation. Interlobular septal thickening and pleural effusion are frequently associated.     

HRCT findings in the lungs of non-smokers with neurofibromatosis

Purpose

Interstitial lung disease in neurofibromatosis (NF) has been disputed and attributed to smoking-related changes. The aim of this study was to describe HRCT findings in the lungs of non-smokers with NF.

Materials and methods

Six never-smokers with NF underwent lung HRCT. Two radiologists evaluated the HRCT scans and a final decision was reached by consensus. The HRCT scans were analyzed with regard to the number, size, location (upper, middle or lower lung zone) and distribution (peripheral and central) of lung cysts and the presence of ground-glass density centrilobular micronodules.

Results

All patients with NF had small (2–18 mm) thin wall cysts and upper-lobe predominant patchy areas of ground-glass density centrilobular micronodules. In five cases, there were 3–17 cysts and in one there were numerous (>100). Lung cysts were central (1), subpleural (1) and in both locations (4).

Conclusion

Interstitial lung disease in NF is not associated with smoking and may be entirely asymptomatic. HRCT may reveal small cysts, with barely perceptible walls therefore not representing emphysema and occasionally a minimal micronodular pattern of ground glass opacity. There was no radiologic evidence of lung fibrosis, honeycombing or severe bullous disease.     

Novel Influenza A (H1N1) Virus Infection in Children: Chest Radiographic and CT Evaluation

Objective

The purpose of this study was to evaluate the chest radiographic and CT findings of novel influenza A (H1N1) virus infection in children, the population that is more vulnerable to respiratory infection than adults.

Materials and Methods

The study population comprised 410 children who were diagnosed with an H1N1 infection from August 24, 2009 to November 11, 2009 and underwent chest radiography at Dankook University Hospital in Korea. Six of these patients also underwent chest CT. The initial chest radiographs were classified as normal or abnormal. The abnormal chest radiographs and high resolution CT scans were assessed for the pattern and distribution of parenchymal lesions, and the presence of complications such as atelectasis, pleural effusion, and pneumomediastinum.

Results

The initial chest radiograph was normal in 384 of 410 (94%) patients and abnormal in 26 of 410 (6%) patients. Parenchymal abnormalities seen on the initial chest radiographs included prominent peribronchial marking (25 of 26, 96%), consolidation (22 of 26, 85%), and ground-glass opacities without consolidation (2 of 26, 8%). The involvement was usually bilateral (19 of 26, 73%) with the lower lung zone predominance (22 of 26, 85%). Atelectasis was observed in 12 (46%) and pleural effusion in 11 (42%) patients. CT (n = 6) scans showed peribronchovascular interstitial thickening (n = 6), ground-glass opacities (n = 5), centrilobular nodules (n = 4), consolidation (n = 3), mediastinal lymph node enlargement (n = 5), pleural effusion (n = 3), and pneumomediastinum (n = 3).

Conclusion

Abnormal chest radiographs were uncommon in children with a swine-origin influenza A (H1N1) virus (S-OIV) infection. In children, H1N1 virus infection can be included in the differential diagnosis, when chest radiographs and CT scans show prominent peribronchial markings and ill-defined patchy consolidation with mediastinal lymph node enlargement, pleural effusion and pneumomediastinum.     

Quantitative assessment of change in regional disease patterns on serial HRCT of fibrotic interstitial pneumonia with texture-based automated quantification system

Objectives

To evaluate the usefulness of a texture-based automated quantification system (AQS) for evaluating the extent and interval change of regional disease patterns on initial and follow-up high-resolution computed tomographies (HRCTs) of fibrotic interstitial pneumonia (FIP).

Methods

Eighty-nine patients with clinically and/or biopsy confirmed usual interstitial pneumonia (UIP) (n?=?71) and non-specific interstitial pneumonia (NSIP) (n?=?18) were included. An AQS to quantify five disease patterns (ground-glass opacity [GGO], reticular opacity [RO], honeycombing [HC], emphysema [EMPH], consolidation [CONS]) and normal lung was developed. The extent and interval changes of each disease pattern, FS (fibrosis score), TA (total abnormal lung fraction) of entire lung on initial and 1-year follow-up HRCTs were quantified. The agreement between the results of AQS and two readers was assessed. Results of AQS were correlated with forced vital capacity (FVC) and carbon monoxide diffusing capacity (DLco).

Results

The Intraclass correlation coefficient (ICC) study revealed acceptable agreement between visual assessment and AQS (r?=?0.78, 0.66 for HC; 0.76, 0.61 for FS; 0.64, 0.68 for TA, initial and follow-up HRCTs, respectively). Linear regression analysis revealed the extent of HC, TA on initial CT, interval changes of FS contributed negatively to DLco, and interval changes of FS, TA contributed negatively to FVC.

Conclusions

Our AQS is comparable with visual assessment for evaluating the disease extent and the interval changes of FIP on HRCT.

Key Points

? HRCT is widely used to assess fibrotic interstitial pneumonia ? An automated quantification system matched well with visual assessment of HRCT ? Abnormal lung fraction on HRCT correlated with the decrease in diffusion capacity ? Automated quantification of HRCT images is useful in assessing fibrotic interstitial pneumonia     

Exogenous lipoid pneumonia: HRCT, MR, and pathologic findings

The objective of this study was to describe high-resolution CT (HRCT) and MR findings of exogenous lipoid pneumonia and to correlate them with pathologic findings. A retrospective review of the medical records of our institution revealed seven patients with a diagnosis of lipoid pneumonia based on clinical data, chest films, bronchoalveolar lavage, and follow-up. Both HRCT and MR imaging were reviewed by two readers. Pathologic examination of the resected specimen or surgical biopsies were also reviewed in the four available cases. The HRCT findings were pulmonary consolidations (n = 6) with fatty (n = 3) or unspecific but low attenuation values (n = 3), areas of ground-glass opacities (n = 5), septal lines, and centrilobular interstitial thickening (n = 5). In five of the seven cases, a crazy-paving pattern of various spread was also present, either isolated (n = 1) or surrounding a pulmonary consolidation. In two cases traction bronchiectasis and cystic changes consistent with fibrosis were seen. At MR imaging (n = 2) a pulmonary consolidation of high signal intensity on T1-weighted image consistent with lipid content was present in one case. Pathologic examination (n = 4) showed the coexistence of lobules with lesions of various ages, sometimes in contiguous lobules, within the same patient. Recent lesions were those with alveolar fill-in by spumous macrophages and almost normal alveolar walls and septae. In more advanced lesions, lobules were filled in with larger vacuoles often surrounded by inflammatory infiltrates of alveolar walls, bronchiolar walls, and septa. The oldest lesions were characterized by fibrosis and parenchymal distortion around large lipid-containing vacuoles. The HRCT findings reflect pathologic findings in exogenous lipoid pneumonia. Although non-specific, consolidation areas of low attenuation values and crazy-paving pattern are frequently associated in exogenous lipoid pneumonia and are indicative of the diagnosis. Received: 24 July 1998; Revision received: 30 December 1998; Accepted: 1 February 1999     

Correlation between HRCT findings,pulmonary function tests and bronchoalveolar lavage cytology in interstitial lung disease associated with rheumatoid arthritis

A prospective study correlating high-resolution computed tomography (HRCT), lung function tests (PFT) and bronchoalveolar lavage (BAL) cytology in patients with interstitial lung disease (ILD) associated with rheumatoid arthritis (RA). Fifty-three RA patients with suspected ILD (19 men, 34 women) underwent 71 HRCT (14 of 53 with sequential HRCT, mean follow-up 24.3 months). The HRCT evaluation by two observers on consensus included a semi-quantitative characterisation of lesion pattern and profusion on representative anatomical levels. Fifty-two HRCT were followed by PFT and BAL. Agreement or discordance of HRCT-, PFT- and BAL findings were analysed with Pearsons correlation, score and McNemars test. Tobacco-fume exposure was estimated in pack years. Smoking/non-smoking groups were compared with Students t test. In 49 of 53 patients, HRCT was suggestive of ILD associated with RA (66 of 71 HRCT). Reticular lesions were found in 40 of 53 patients, in 15 of 40 presenting as mixed pattern with ground-glass opacities (GGO). Pure reticular patterns predominated in patients with long duration of ILD (p>0.01). Pure GGO were not observed. Lesion profusion was highly variable and correlated moderately negative with diffusion capacity (mean 88.2% (SD±20.9%); r=–0.54; p<0.001) and very weak with vital capacity and FEV1 (mean values 92.2% (SD±18.3%); r=–0.27; p<0.05 and 89.8% (SD±17.5%); r=–0.31; p<0.01). In patients with GGO, BAL differentials tended towards neutrophilia (=0.39; p=0.04; McNemar test p>0.2), but not towards lymphocytosis (=0.10; p=0.23; McNemar test p>0.2). Differences in smoking history were not significant (p>0.1). The HRCT appears most appropriate for the detection and follow-up of ILD associated with RA. The PFT and BAL correlate only partially with lesion profusion or grading on HRCT, but they contribute valuable information about dynamic lung function and differential diagnoses (pneumonia, medication side effects).