Distribution Of Ground-glass Opacity Research Articles

Artificial intelligence-based analysis of the spatial distribution of abnormal computed tomography patterns in SARS-CoV-2 pneumonia: association with disease severity

BackgroundThe substantial heterogeneity of clinical presentations in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia still requires robust chest computed tomography analysis to identify high-risk patients. While extension of ground-glass opacity and consolidation from peripheral to central lung fields on chest computed tomography (CT) might be associated with severely ill conditions, quantification of the central-peripheral distribution of ground glass opacity and consolidation in assessments of SARS-CoV-2 pneumonia remains unestablished. This study aimed to examine whether the central-peripheral distributions of ground glass opacity and consolidation were associated with severe outcomes in patients with SARS-CoV-2 pneumonia independent of the whole-lung extents of these abnormal shadows.MethodsThis multicenter retrospective cohort included hospitalized patients with SARS-CoV-2 pneumonia between January 2020 and August 2021. An artificial intelligence-based image analysis technology was used to segment abnormal shadows, including ground glass opacity and consolidation. The area ratio of ground glass opacity and consolidation to the whole lung (GGO%, CON%) and the ratio of ground glass opacity and consolidation areas in the central lungs to those in the peripheral lungs (GGO(C/P)) and (CON(C/P)) were automatically calculated. Severe outcome was defined as in-hospital death or requirement for endotracheal intubation.ResultsOf 512 enrolled patients, the severe outcome was observed in 77 patients. GGO% and CON% were higher in patients with severe outcomes than in those without. Multivariable logistic models showed that GGO(C/P), but not CON(C/P), was associated with the severe outcome independent of age, sex, comorbidities, GGO%, and CON%.ConclusionIn addition to GGO% and CON% in the whole lung, the higher the ratio of ground glass opacity in the central regions to that in the peripheral regions was, the more severe the outcomes in patients with SARS-CoV-2 pneumonia were. The proposed method might be useful to reproducibly quantify the extension of ground glass opacity from peripheral to central lungs and to estimate prognosis.

HRCT chest in patients suffering from COVID-19: Experience from a tertiary care centre in India during second wave of the pandemic

Abstract Aim The objective of the present study is to describe high-resolution CT (HRCT) chest manifestations of coronavirus disease 2019 (COVID-19) patients during second wave of the pandemic in a tertiary care hospital in New Delhi, India. We also aim to compare the findings on the HRCT chest during the second wave of COVID-19 with the data form earlier outbreaks and to look for any features specific to the second wave and thus indirectly to the delta variant of SARS-CoV-2. We also assessed the severity of the pulmonary involvement based on HRCT findings. Methods We analysed HRCT chest findings in 237 patients with COVID-19 admitted at our institute from 1st April 2021 to 31st May 2021. Covid-19 infection was confirmed by reverse transcription polymerase chain reaction (rt-PCR) or rapid antigen test (RAT) in all these patients. Results The mean age in our study group was 51.3 ± 12.1 years (range 19–79 years) comprising of 136 males (57.4%) and 101 females (42.6%). The majority of the patients showed bilateral (95.3%) and peripheral (42.6%) distribution of the disease. Ground glass opacities were the most common finding, seen in 214 (90.3%) patients, followed by interlobular septal thickening in 202 (85.8%) and crazy paving in 194 (81.3%) patients. Majority (36.7%) of these patients had a CT severity score above 20 indicating severe disease. Conclusion A typical pattern of peripheral subpleural often bilateral distribution of ground glass opacities on HRCT chest usually points to the possibility of COVID-19 pneumonia. The higher incidence of abnormalities on HRCT chest in patients with infection mainly from the delta variant of SARS-Cov-2 was mainly because of the more severe disease in the population. More research is needed to further evaluate the role of HRCT chest in the diagnosis of COVID-19 caused by different strains of the virus.

Brixia Score for Predicting Mortality and Length of Stay in COVID-19 Confirmed Patients at the Hospital in Bandung

On March 11, 2020, the World Health Organization declared the COVID-19 pandemic. This disease damages the lung and resulting mild to severe pneumonia. This study aimed to determine the value of the Brixia score for predicting mortality and length of stay of COVID-19 confirmed patients. The study design was case-control with secondary data from digital medical records of COVID-19 confirmed patients (December 2020 to February 2021). All patients' chest x-rays (CXR) were scored using the Brixia score. Logistic regression and the Spearman rank correlation test were used to identify mortality and length of stay predictors. There were 636 subjects included in this study, with the proportion of deceased patients (case group) being 20.3% (95% CI=17.33, 23.59%). Most CXR findings had signs of pneumonia (95.1%), including ground-glass opacities (GGOs) mixed with consolidation. The distribution of GGOs and consolidation were most frequent in the peripheral of survived patients (83.9%), while the deceased group had peripheral involvements mixed with medial (45.0%) and bilateral (22.2%). The mean Brixia score in the group of decease patients was significantly higher than the group of survived patients (11.95 vs 6.73, p=0.00). Brixia score had an OR of 1.14, 95% CI=1.07, 1.21 after adjusting by age, SpO2 level, and comorbid. The chance of dying was higher than 50% if the Brixia score reached to score of 15 (probability=49%, 95% CI=41, 56%). However, the Brixia score has no significant correlation with length of stay (rho=0.05, p=0.24). In conclusion, the CXR Brixia score can predict mortality, but it can not predict the length of stay of hospitalized COVID-19 confirmed patients.

Coronavirus Disease (COVID-19) Compared with Middle East Respiratory Syndrome (MERS): A Radiological Perspective.

This study aims to describe the radiological findings in chest radiographs (CXRs) of patients with coronavirus disease (COVID-19) and the Middle East respiratory syndrome (MERS) and to compare the radiological patterns of the two diseases. A retrospective cohort study was conducted in a tertiary care hospital in the Southern region of Saudi Arabia. The CXRs were evaluated for the presence and distribution of ground-glass opacities (GGO), consolidation, pleural effusions, pneumothorax, cavitation, and nodules. A total of 120 CXRs from 15 MERS and six COVID-19 patients were assessed. In the first available CXR, GGO was present in 11 (73%) of the MERS patients (18% located in the middle zones and 67% located peripherally) and in 100% of COVID-19 patients (peripheral and middle zone involvement in all patients). In the first available CXRs, consolidation was present in 10 MERS patients (67%) and in all six COVID-19 patients, while it was present in all patients of both groups when all the available CXRs were considered. Confluent consolidation was present in 47% of the MERS patients and 50% of COVID-19 patients. All the fatal cases had confluent consolidation and radiological signs of acute respiratory distress syndrome (ARDS). Pneumothorax was present in 13% of patients, with 100% mortality, and pleural effusion was present in 47% of patients, with 57% mortality. Lung nodules were present in one patient of each group. COVID-19 patients showed earlier development of GGO and consolidation with greater involvement of the middle and peripheral lung zones. Confluent consolidation and ARDSlike radiological findings were associated with high mortality. Pneumothorax and pleural effusions were more frequent in MERS patients, with high associated mortality.

SARS-COV-2 PNEUMONIA LEADING TO PROGRESSION OF PULMONARY SARCOIDOSIS

TOPIC: Pulmonary Manifestations of Systemic Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: The implication of COVID 19 pneumonia on chronic inflammatory disorders is not clearly known. Due to a lack of data, it is difficult to predict the disease course post-COVID 19 pneumonia. Here, we present a case of stable sarcoidosis that progressed rapidly after COVID 19 pneumonia. CASE PRESENTATION: A 43-year-old male, with a history of sarcoidosis, briefly treated with steroids at initial diagnosis and in remission for the last six years, was admitted for dyspnea and hypoxia (room air oxygen saturation 83%) secondary to COVID 19 pneumonia diagnosed a week prior to admission. Chest X-ray on admission showed diffuse bilateral interstitial and airspace opacities. He was treated with dexamethasone and remdesevir. The clinical status of the patient improved after a week, and he was discharged on prednisone taper (10 mg for 5 days). Four weeks later, the patient had a recurrence of dyspnea on exertion with occasional hemoptysis. Computed Tomography (CT) scan of the chest showed honeycombing and reticulations in bilateral upper lobes, interstitial thickening, and worsening hilar and mediastinal lymphadenopathy (sarcoidosis Scadding stage IV). Labs were significant for elevated serum soluble interleukin-2 (IL-2) receptor and calcitriol levels. Pulmonary function test showed a restrictive defect with reduced diffusion capacity. The patient was started on prednisone. Repeat CT scan after three months showed improvement in ground-glass opacities and stable scarring. Fine needle aspiration biopsy of subcarinal lymph node confirmed non-caseating granulomatous inflammation. The patient was started on mycophenolate mofetil, tapered off prednisone, and is being evaluated for a lung transplant. DISCUSSION: The main pathogenesis related to sarcoidosis is the formation of granulomas due to sustained host immune system stimulation from various known and unknown antigens. Activation of the immune system as evidenced by elevated inflammatory makers in viral infections may in turn precipitate the relapse and progression of inflammatory disorders such as sarcoidosis. It is difficult to distinguish between the sequela of COVID 19 pneumonia and sarcoidosis progression. CT scan findings in fibrotic sarcoidosis have upper lobe predilection. However, the distribution of ground-glass opacities and fibrosis in COVID 19 pneumonia is usually peripheral and may have lower lobe predilection. Close monitoring is important to look for activation of sarcoidosis post COVID 19 pneumonia. CONCLUSIONS: Implications of COVID 19 infection on pathogenesis and progression of sarcoid are important to understand, and more research is required so that clinicians can be vigilant about worsening pulmonary function and intervene in a timely manner. REFERENCE #1: Ramdani H, Benelhosni K, Moatassim Billah N, Nassar I. COVID-19 pneumonia in a patient with sarcoidosis: A case report. Clin Case Rep. 2020 Dec 23;9(2):910-913. REFERENCE #2: Tana C, Mantini C, Cipollone F, Giamberardino MA. Chest Imaging of Patients with Sarcoidosis and SARS-CoV-2 Infection. Current Evidence and Clinical Perspectives. Diagnostics (Basel). 2021 Jan 27;11(2):183. DISCLOSURES: No relevant relationships by Salim Daouk, source=Web Response No relevant relationships by Samiksha Gupta, source=Web Response No relevant relationships by Ahmad Hassan, source=Web Response No relevant relationships by SYED HUSSAIN, source=Web Response No relevant relationships by Miloni Parmar, source=Web Response

A single-center comparative study of lung ultrasound versus chest computed tomography during the COVID-19 era.

BackgroundLung ultrasound (LUS) is a bedside imaging tool that has proven useful in identifying and assessing the severity of pulmonary pathology. The aim of this study was to determine LUS patterns, their clinical significance, and how they compare to CT findings in hospitalized patients with coronavirus infection.MethodsThis observational study included 62 patients (33 men, age 59.3±15.9 years), hospitalized with pneumonia due to COVID-19, who underwent chest CT and bedside LUS on the day of admission. The CT images were analyzed by chest radiographers who calculated a CT visual score based on the expansion and distribution of ground-glass opacities and consolidations. The LUS score was calculated according to the presence, distribution, and severity of anomalies.ResultsAll patients had CT findings suggestive of bilateral COVID-19 pneumonia, with an average visual scoring of 8.1±2.9%. LUS identified 4 different abnormalities, with bilateral distribution (mean LUS score: 26.4±6.7), focal areas of non-confluent B lines, diffuse confluent B lines, small sub-pleural micro consolidations with pleural line irregularities, and large parenchymal consolidations with air bronchograms. LUS score was significantly correlated with CT visual scoring (rho = 0.70; p<0.001). Correlation analysis of the CT and LUS severity scores showed good interclass correlation (ICC) (ICC =0.71; 95% confidence interval (CI): 0.52–0.83; p<0.001). Logistic regression was used to determine the cut-off value of ≥27 (area under the curve: 0.97; 95% CI: 90-99; sensitivity 88.5% and specificity 97%) of the LUS severity score that represented severe and critical pulmonary involvement on chest CT (CT: 3-4).ConclusionWhen combined with clinical data, LUS can provide a potent diagnostic aid in patients with suspected COVID-19 pneumonia, reflecting CT findings.

Outcome of asymptomatic patients with positive SARS-CoV-2 viral RNA reverse transcriptase-PCR undergoing surgery: A matched cohort study.

Outcome of asymptomatic patients with positive SARS-CoV-2 viral RNA reverse transcriptase-PCR undergoing surgery: A matched cohort study.

Suspected SARS-CoV-2 infection with fever and coronary heart disease: A case report

BACKGROUNDThe coronavirus disease 2019 (COVID-19) is an emerging infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Suspected cases accounted for a large proportion in the early stage of the COVID-19 outbreak. The deviation of the nucleic acid test by throat swab (the current gold standard of COVID-19) caused by variation in sampling techniques and reagent kits and coupled with nonspecific clinical manifestations make confirmation of the suspected cases difficult. Proper management of the suspected cases of COVID-19 is crucial for disease control.CASE SUMMARYA 65-year-old male presented with fever, lymphopenia, and chest computed tomography (CT) images similar to COVID-19 after percutaneous coronary intervention. The patient was diagnosed as having bacterial pneumonia with cardiogenic pulmonary edema instead of COVID-19. This was based on four negative results for throat swab detection of SARS-CoV-2 nucleic acid using reverse transcriptase-polymerase chain reaction assay and one negative result for serological antibody of SARS-CoV-2 with the serological assay. Additionally, the distribution of ground-glass opacities and thickened blood vessels from the CT images differed from COVID-19 features, which further supported the exclusion of COVID-19.CONCLUSIONDistinguishing COVID-19 patients from those with bacterial pneumonia with cardiogenic pulmonary edema can be difficult. Therefore, it requires serious identification.

Clinical characteristics of 41 patients with pneumonia due to 2019 novel coronavirus disease (COVID-19) in Jilin, China

BackgroundThe clinical characteristics of patients with confirmed 2019 novel coronavirus disease (COVID-19) in Jilin Province, China were investigated.MethodsClinical, laboratory, radiology, and treatment data of 41 hospitalized patients with confirmed COVID-19 were retrospectively collected. The population was stratified by disease severity as mild, moderate, or severe, based on guidelines of the National Health and Medical Commission of China.ResultsThe 41 hospitalized patients with COVID-19 were studied, and the median age was 45 years (interquartile range [IQR], 31–53; range, 10–87 years) and 18 patients (43.9%) were female. All of the patients had recently visited Wuhan or other places (ie, Beijing, Thailand) or had Wuhan-related exposure. Common symptoms included fever (32[78%]) and cough (29[70.7%]). All patients were without hepatitis B/C virus hepatitis. CRP (C-reactive protein, 11.3 mg/L [interquartile range {IQR}, 2.45–35.2]) was elevated in 22 patients (53.7%), and cardiac troponin I (1.5 ng/mL [IQR, 0.8–5.0]) was elevated in 41 patients (100%). Chest computed tomographic scans showed bilateral ground glass opacity (GGO) or GGO with consolidation in the lungs of 27(65.9%) patients. 31(75.6%) patients had an abnormal electrocardiograph (ECG). Comparing the three groups, the levels of CRP and cardiac troponin I, GGO distribution in bilateral lungs, and electrocardiogram changes were statistically significant (p < 0.05). Cardiac troponin I had a strong positive correlation with CRP (r = 0.704, p = 0.042) and LDH (r = 0.738, p = 0.037).ConclusionSignificant differences among the groups suggest that several clinical parameters may serve as biomarkers of COVID-19 severity at hospital admission. Elevated cTnI could be considered as a predictor of severe COVID-19, reflecting the prognosis of patients with severe COVID-19. The results warrant further inspection and confirmation.

Lung Ultrasound in COVID-19 Pneumonia: Correlations with Chest CT on Hospital admission

Background: Lung ultrasound (LUS) is an accurate, safe, and cheap tool assisting in the diagnosis of several acute respiratory diseases. The diagnostic value of LUS in the workup of coronavirus disease-19 (COVID-19) in the hospital setting is still uncertain. Objectives: The aim of this observational study was to explore correlations of the LUS appearance of COVID-19-related pneumonia with CT findings. Methods: Twenty-six patients (14 males, age 64 ± 16 years) urgently hospitalized for COVID-19 pneumonia, who underwent chest CT and bedside LUS on the day of admission, were enrolled in this observational study. CT images were reviewed by expert chest radiologists, who calculated a visual CT score based on extension and distribution of ground-glass opacities and consolidations. LUS was performed by clinicians with certified competency in thoracic ultrasonography, blind to CT findings, following a systematic approach recommended by ultrasound guidelines. LUS score was calculated according to presence, distribution, and severity of abnormalities. Results: All participants had CT findings suggestive of bilateral COVID-19 pneumonia, with an average visual scoring of 43 ± 24%. LUS identified 4 different possible ­abnormalities, with bilateral distribution (average LUS score 15 ± 5): focal areas of nonconfluent B lines, diffuse confluent B lines, small subpleural microconsolidations with pleural line irregularities, and large parenchymal consolidations with air bronchograms. LUS score was significantly correlated with CT visual scoring (r = 0.65, p < 0.001) and oxygen saturation in room air (r = –0.66, p < 0.001). Conclusion: When integrated with clinical data, LUS could represent a valid diagnostic aid in patients with suspect COVID-19 pneumonia, which reflects CT findings.

Chest CT features of coronavirus disease 2019 (COVID-19) pneumonia: key points for radiologists

COVID-19 is an emerging infection caused by a novel coronavirus that is moving so rapidly that on 30 January 2020 the World Health Organization declared the outbreak a Public Health Emergency of International Concern and on 11 March 2020 as a pandemic. An early diagnosis of COVID-19 is crucial for disease treatment and control of the disease spread. Real-time reverse-transcription polymerase chain reaction (RT-PCR) demonstrated a low sensibility; therefore chest computed tomography (CT) plays a pivotal role not only in the early detection and diagnosis, especially for false negative RT-PCR tests, but also in monitoring the clinical course and in evaluating the disease severity. This paper reports the CT findings with some hints on the temporal changes over the course of the disease: the CT hallmarks of COVID-19 are bilateral distribution of ground glass opacities with or without consolidation in the posterior and peripheral lung, but the predominant findings in later phases include consolidations, linear opacities, “crazy-paving” pattern, “reversed halo” sign and vascular enlargement. The CT findings of COVID-19 overlap with the CT findings of other diseases, in particular the viral pneumonia including influenza viruses, parainfluenza virus, adenovirus, respiratory syncytial virus, rhinovirus, human metapneumovirus, etc. There are differences as well as similarities in the CT features of COVID-19 compared with those of the severe acute respiratory syndrome. The aim of this article is to review the typical and atypical CT findings in COVID-19 patients in order to help radiologists and clinicians to become more familiar with the disease.

CT in coronavirus disease 2019 (COVID-19): a systematic review of chest CT findings in 4410 adult patients.

ObjectiveThe objective of this systematic review was to evaluate the key imaging manifestations of COVID-19 on chest CT in adult patients by providing a comprehensive review of the published literature.MethodsWe performed a systematic literature search from the PubMed, Google Scholar, Embase, and WHO databases for studies mentioning the chest CT imaging findings of adult COVID-19 patients.ResultsA total of 45 studies comprising 4410 patients were included. Ground glass opacities (GGO), in isolation (50.2%) or coexisting with consolidations (44.2%), were the most common lesions. Distribution of GGOs was most commonly bilateral, peripheral/subpleural, and posterior with predilection for lower lobes. Common ancillary findings included pulmonary vascular enlargement (64%), intralobular septal thickening (60%), adjacent pleural thickening (41.7%), air bronchograms (41.2%), subpleural lines, crazy paving, bronchus distortion, bronchiectasis, and interlobular septal thickening. CT in early follow-up period generally showed an increase in size, number, and density of GGOs, with progression into mixed areas of GGOs plus consolidations and crazy paving, peaking at 10–11 days, before gradually resolving or persisting as patchy fibrosis. While younger adults more commonly had GGOs, extensive/multilobar involvement with consolidations was prevalent in the older population and those with severe disease.ConclusionThis review describes the imaging features for diagnosis, stratification, and follow-up of COVID-19 patients. The most common CT manifestations are bilateral, peripheral/subpleural, posterior GGOs with or without consolidations with a lower lobe predominance. It is pertinent to be familiar with the various imaging findings to positively impact the management of these patients.Key Points • Ground glass opacities (GGOs), whether isolated or coexisting with consolidations, in bilateral and subpleural distribution, are the most prevalent chest CT findings in adult COVID-19 patients. • Follow-up CT shows a progression of GGOs into a mixed pattern, reaching a peak at 10–11 days, before gradually resolving or persisting as patchy fibrosis. • Younger people tend to have more GGOs. Older or sicker people tend to have more extensive involvement with consolidations. Electronic supplementary materialThe online version of this article (10.1007/s00330-020-06975-7) contains supplementary material, which is available to authorized users.

High resolution computed tomography and classification of children with interstitial lung diseases.

High resolution computed tomography (HRCT) was used to classify children with interstitial lung diseases (ILD). Sixty children with ILD underwent HRCT in supine position under free-respiratory conditions during scanning. Children under 5 years old were sedated with chloral hydrate and the scanning scope was from the lung apex to the diaphragm. In children older than 5 years old, scans were obtained at three levels: aortic arch, tracheal carina, and 1 cm above the right diaphragm. Five infectious patients were followed up. Two experienced radiologists read the films blindly to observe the type and distribution of ground-glass opacities and bronchovascular bundle abnormalities. Bronchovascular bundles were thick in 49 patients, and were thick and stiff in 27 patients. Of the 41 infectious patients, 39 showed thickened bronchovascular bundles, and 26 showed thick and stiff bronchovascular bundles. Of the 19 non-infectious patients, bronchovascular bundles were thickened in 10 patients, and were thick and stiff in 1 patient. Forty-one patients showed lobular ground-glass opacity (32 infectious, 9 non-infectious). Twenty-seven patients showed both bronchovascular bundle abnormality and lobular ground-glass opacity (20 infectious, 7 non-infectious). Eighteen patients showed patchy or mosaic ground-glass opacity (16 infectious, 2 non-infectious). There were 4 cases of bronchiectasis. HRCT is the first non-invasive diagnostic method for children with ILD, and its different manifestations can be classified. In early manifestation, bronchovascular bundles were abnormal and complicated with lobular ground-glass opacity. Patchy ground-glass opacity was the most common manifestation, and appeared to be difficult to disappear. Bronchiectasis indicated that the disease is irretrievable.

Clinical features of three cases with pulmonary alveolar proteinosis secondary to myelodysplastic syndrome developed during the course of Behçet's disease

We have previously reported that myelodysplastic syndrome (MDS) is the most common underlying disease in cases of secondary pulmonary alveolar proteinosis (PAP). Here, we present 3 MDS cases in which PAP developed during the course of Behçet's disease (BD). All patients carried trisomy 8 in the bone marrow. Chest HRCT scans showed variable distribution of ground glass opacities, but none of the scans showed so called "crazy paving appearance". Two patients with intestinal BD who underwent potent immunosuppressive therapy died of sepsis. These findings demonstrate that PAP secondary to MDS may be occasionally associated with BD.

High-resolution computed tomography findings of swine-origin influenza A (H1N1) virus (S-OIV) infection: comparison with scrub typhus

Swine-origin influenza A (H1N1) virus (S-OIV) infection and scrub typhus, also known as tsutsugamushi disease can manifest as acute respiratory illnesses, particularly during the late fall or early winter, with similar radiographic findings, such as a predominance of ground-glass opacity (GGO). To differentiate S-OIV infection from scrub typhus using high-resolution computed tomography (HRCT). We retrospectively reviewed the HRCT findings of 14 patients with S-OIV infection and 10 patients with scrub typhus. We assessed the location, cross-sectional distribution, and the presence of a peribronchovascular distribution of GGO and consolidations on HRCT. We also assessed the presence of interlobular septal thickening, bronchial wall thickening, pneumothorax, pneumomediastinum, pleural effusion, and mediastinal or axillary lymph node enlargement. Scrub typhus was more common than S-OIV in elderly patients (P < 0.001). The monthly incidences of S-OIV and scrub typhus infection reached a peak between October and November. About 86% of S-OIV patients and 80% of scrub typhus patients presented with GGO. About 67% of the GGO lesions in S-OIV had a peribronchovascular distribution, but this was absent in scrub typhus (P = 0.005). Consolidation (93% vs. 10%, P < 0.001) and bronchial wall thickening (43% vs. 0%, P = 0.024) were more frequent in S-OIV infection than scrub typhus. Interlobular septal thickening (90% vs. 36%, P = 0.013) and axillary lymphadenopathy (90% vs. 0%, P < 0.001) were more common in scrub typhus than S-OIV infection. There was considerable overlap in HRCT findings between S-OIV infection and scrub typhus. However, S-OIV showed a distinctive peribronchovascular distribution of GGO lesions. Consolidation and bronchial wall thickening were seen more frequently in S-OIV infection, whereas interlobular septal thickening and axillary lymphadenopathy were more common in scrub typhus. Thus, CT could be helpful for differential diagnosis between S-OIV infection and scrub typhus.

Reexpansion Pulmonary Edema

To determine the computed tomography (CT) imaging features of reexpansion pulmonary edema. A retrospective review was performed of 22 consecutive patients with clinical and radiologic features consistent with reexpansion pulmonary edema (14 male, 8 female; mean age, 56±22.8 y; range, 19 to 82 y) and with available CT scan images within 3 days of drainage of pleural effusion or pneumothorax. The CT images were reviewed by 2 chest radiologists with consensus for the presence, extent, and distribution of ground-glass opacities, septal thickening, consolidation, presence of persistent areas of atelectasis, vascular caliber, linear opacities, residual midline shift, and trapped lung. CT findings included ipsilateral ground-glass opacities (n=21, 95%), smooth septal thickening (n=17, 77%), consolidation (n=14, 68%), and persistent foci of atelectasis (n=19, 86%). Less commonly seen features included air-bronchograms (n=6, 27%) and nodules (n=5, 23%) [centrilobular, n=4 (18%); random, n=1 (4.5%)]. Contralateral abnormalities were seen in 8 cases (36%) and included ground-glass opacities in 6 patients, interlobular septal thickening in 3 patients (13.6%), and consolidation in 3 patients. The most common CT findings of reexpansion pulmonary edema include ipsilateral ground-glass opacities, septal thickening, foci of consolidation, and areas of atelectasis.

Comparative study of clinical, pathological and HRCT findings of primary alveolar proteinosis and silicoproteinosis

To compare the clinical, high-resolution computed tomography (HRCT) and pathological findings of primary alveolar proteinosis (PAP) and silicoproteinosis. The study included 15 patients with PAP (6 women, 9 men, mean age 31 years) and 13 with silicoproteinosis (13 men, mean age 29.5 years). PAP was diagnosed by lung biopsy in 13 and bronchoalveolar lavage in two patients and silicoproteinosis by bronchoalveolar lavage in 10 and autopsy in three cases. HRCT images were reviewed by two chest radiologists with consensus for the presence, extent and distribution of ground-glass opacities, septal thickening, consolidation and nodules. Radiological-pathological correlation was performed by one radiologist and one chest pathologist. Seven (46%) patients with PAP were asymptomatic; the remainder presented slowly progressive dyspnea and dry cough. All silicoproteinosis patients had dry cough and rapidly progressive dyspnea. The most common HRCT finding on PAP was the crazy-paving pattern (93%). All cases had areas of geographic sparing in the affected lung. The most common finding in silicoproteinosis (92%) was dependent consolidation with calcification in 83%. Centrilobular nodules were common (85%). On pathology, both diseases demonstrated intra-alveolar accumulation of PAS material, thickening of interlobular septae and alveolar walls and no evidence of fibrosis. A few silica particles were seen in silicoproteinosis. Despite the pathological similarities, PAP and silicoproteinosis have distinct clinical and imaging features and prognosis. Bilateral crazy-paving pattern with areas of geographic sparing is characteristic for PAP. Silicoproteinosis presents with bilateral dependent consolidation often with areas of calcification. The crazy-paving pattern is not seen in silicoproteinosis.

Nonspecific Interstitial Pneumonia and Idiopathic Pulmonary Fibrosis: Changes in Pattern and Distribution of Disease over Time

To retrospectively assess the change in disease pattern of nonspecific interstitial pneumonia (NSIP) and idiopathic pulmonary fibrosis (IPF) findings seen at thin-section computed tomography (CT) at long-term follow-up and to compare the same with initial findings at CT. The study included 48 patients (28 men, 20 women; mean age, 57.5 years) with biopsy-proved NSIP (n = 23) or IPF (n = 25) who underwent CT at initial diagnosis and at follow-up 34-155 months later. The CT scans were randomized and reviewed by two independent thoracic radiologists for pattern and distribution of ground-glass opacity (GGO), reticulation, traction bronchiectasis and bronchiolectasis, and honeycombing. Statistical analysis was performed by using nonparametric methods and univariate logistic regression. Follow-up CT in patients with NSIP showed marked decrease in the extent of GGO, increase in reticulation, and a greater likelihood of peripheral distribution (all P < .05). At presentation, the CT findings were interpreted as suggestive of NSIP in 18 of 23 patients with NSIP and indeterminate or suggestive of IPF in five. In five (28%) of 18 patients with initial findings suggestive of NSIP, the follow-up CT scans were interpreted as more suggestive of IPF. No CT features seen at presentation allowed distinction between patients with NSIP that maintained an NSIP pattern at follow-up and those that progressed to an IPF pattern. At follow-up CT, 28% of patients with initial CT findings suggestive of NSIP progressed to findings suggestive of IPF. Similar initial CT findings for NSIP may have different imaging outcomes.

Widespread Ground-Glass Opacity of the Lung in Consecutive Patients Undergoing CT: Does Lobular Distribution Assist Diagnosis?

Our purpose was to establish the most frequent diagnoses associated with widespread ground-glass opacity on CT and to determine if the distribution of ground-glass opacity at a lobular level affects the likelihood of a given diagnosis. A retrospective search of our department's CT database from January 1998 through December 2000 revealed 153 cases of ground-glass opacity. Patients evaluated using bronchoscopy or open biopsy within 30 days (mean, 6.9 days) of imaging with ground-glass opacity as the predominant high-resolution CT finding were selected. There were 21 men and 16 women with a mean age of 51.4 years. Two chest radiologists, unaware of the clinical diagnoses, independently recorded lobular distributions. Consensus interpretation was used for discrepancies. Primary distributions were recorded as lobular (geographic ground-glass opacity marginated by septal anatomy), centrilobular (ground-glass opacity related to bronchovascular anatomy), or random. Infectious and other histologic diagnoses fell into four diagnostic groups: atypical pneumonia, chronic infiltrative interstitial disease, acute air-space filling, and drug toxicity. Ground-glass opacity was most frequently associated with acute atypical pneumonia (n = 12, 32%), chronic infiltrative disease (n = 10, 27%), acute air-space filling (n = 6, 16%), and drug toxicity (n = 4, 11%). In five patients, a definitive diagnosis was not established. Ground-glass opacity was most commonly randomly distributed (n = 16, 43%), followed by lobular (n = 15, 41%) and centrilobular (n = 6, 16%) distributions. Distribution did not correlate with diagnostic group. In unselected cases of ground-glass opacity evaluated at a tertiary institution, atypical infection and chronic infiltrative interstitial disease accounted for 59% of diagnoses. Distribution at a lobular level did not differentiate underlying causes.

Chest CT findings and clinical features in mild Legionella pneumonia.

To evaluate mild Legionella pneumonia (LP) by chest CT, and clinical features. In June 2000, an outbreak of LP occurred in Japan. Eight patients with mild LP (seven men, one woman; mean age 55.9 years) had fevers of more than 38 degrees C, but respiratory symptoms were observed only in four. Chest CT was performed before starting an appropriate treatment. CT images were assessed by the distribution of ground-glass opacity (GGO), consolidation, and the existence of pleural effusion. Chest CT findings: multiple segments were affected in all of the patients, (pleural effusion in three, peripheral lung consolidation in seven, and GGO in seven). GGO was located around the consolidation in six patients. Mild LP may present as fever without respiratory symptoms. Chest CT findings of mild LP are bilateral, multiple affected segments and peripheral lung consolidation with GGO.