Clinico-radiological correlation and prognostic value of baseline chest computed tomography in eosinophilic granulomatosis with polyangiitis

OBJECTIVES

While chest high-resolution CT (HRCT) is correlated to severity and prognosis in asthma, it has not been studied in eosinophilic granulomatosis with polyangiitis (EGPA). Our objective is to study the prognostic value of baseline HRCT in EGPA patients.

METHODS

Retrospective, multicentre observational study in three French hospitals, including EGPA patients with available chest HRCT before any systemic treatment. Two experienced radiologists blinded to clinical data evaluated HRCT images using semi-quantitative scoring. HRCT characteristics were correlated with clinical features and outcome.

RESULTS

Among 46 patients, 38 (82.6%) had abnormal parenchymal findings on HRCT, including bronchial wall thickening (69.6%), mosaic perfusion (63.0%), ground-glass opacities (32.6%), bronchiectasis (30.4%), mucous plugging (21.7%) and consolidations (17.4%). Patients were clustered into three groups depending on HRCT features: ground-glass pattern, i.e. with ground-glass opacities with or without bronchial abnormalities (group 1, 28.3%), bronchial pattern (group 2, 41.3%) and extra-pulmonary pattern with no significant abnormality (group 3, 30.4%). Group 2 showed less frequent cardiac involvement (31.6 vs 46.2 and 42.9% in groups 1 and 3), more frequent positive ANCA (52.6 vs 0.0 and 14.3%) and higher eosinophil count (median 7510 vs 4000 and 4250/mm3). Group 1 showed worse prognosis with more frequent steroid-dependency (58.3 vs 11.1 and 28.6%) and requirement for mepolizumab (25.0 vs 11.1 and 7.1%). Conversely, group 2 showed a better outcome with higher rates of remission (88.9 vs 41.6 and 71.4%).

CONCLUSION

Chest HRCT at diagnosis of EGPA may have prognostic value and help clinicians better manage these patients.

A study of the diagnostic value of a modified transthoracic lung ultrasound scoring method in interstitial lung disease

Background

Interstitial lung disease (ILD) is a serious complication of connective tissue disease (CTD) with significant morbidity and mortality. Lung ultrasound (LUS) has been widely used in the diagnosis of a variety of lung diseases. However, there is no standard ultrasound scanning method or scoring method for connective tissue disease associated with interstitial lung disease (CTD-ILD); therefore, it is necessary to establish a set of standard evaluation methods.

Methods

A total of 60 consecutive patients with clinically confirmed CTD and suspected ILD were prospectively included in this study. LUS and high-resolution computed tomography (HRCT) were used to examine all patients. The time between HRCT and LUS examinations was less than 2 weeks. The ultrasonographic results were evaluated with the modified scoring method and the Buda scoring method. The imaging results were evaluated with the HRCT Warrick scoring method. The primary aim was to evaluate the diagnostic value of a modified ultrasound scoring method in CTD-ILD.

Results

The results of the Youden index for the diagnosis of CTD-ILD by the modified method, the Buda method, and the HRCT method were 0.845, 0.711, and 0.911, respectively, with areas under the receiver operating characteristic (ROC) curve (AUC) of 0.982 [95% confidence interval (CI): 0.945-1.000], 0.950 (95% CI: 0.851-0.990), and 0.985 (95% CI: 0.949-1.000), respectively. With a clinical diagnosis as the gold standard, the consistency of the modified method and the HRCT method for CTD-ILD was high (Kappa values =0.872 and 0.913, respectively). The values of the modified method and the Buda method consistently and significantly increased with the increasing severity of CTD-ILD. For the former, there were significant differences between the mild, moderate, and severe groups (P<0.05). The ROC curve used to calculate the modified ultrasound score predicted the critical values of mild and severe pulmonary fibrotic lesions at 34 points (sensitivity, 100%; specificity, 92.9%; AUC =0.933; 95% CI: 0.807-1.000) and 64.5 points (sensitivity, 92.0%; specificity, 85.3%; AUC =0.972; 95% CI: 0.929-1.000).

Conclusions

The modified ultrasound method has a higher diagnostic value than the Buda method for CTD-ILD.

Effects of non-stationary blur on texture biomarkers of bone using Ultra-High Resolution CT

Purpose

To advance the development of radiomic models of bone quality using the recently introduced Ultra-High Resolution CT (UHR CT), we investigate inter-scan reproducibility of trabecular bone texture features to spatially-variant azimuthal and radial blurs associated with focal spot elongation and gantry rotation.

Methods

The UHR CT system features 250×250 μm detector pixels and an x-ray source with a 0.4×0.5 mm focal spot. Visualization of details down to ~150 μm has been reported for this device. A cadaveric femur was imaged on UHR CT at three radial locations within the field-of-view: 0 cm (isocenter), 9 cm from the isocenter, and 18 cm from the isocenter; we expect the non-stationary blurs to worsen with increasing radial displacement. Gray level cooccurrence (GLCM) and gray level run length (GLRLM) texture features were extracted from 237 trabecular regions of interest (ROIs, 5 cm diameter) placed at corresponding locations in the femoral head in scans obtained at the different shifts. We evaluated concordance correlation coefficient (CCC) between texture features at 0 cm (reference) and at 9 cm and 18 cm. We also investigated whether the spatially-variant blurs affect K-means clustering of trabecular bone ROIs based on their texture features.

Results

The average CCCs (against the 0 cm reference) for GLCM and GLRM features were ~0.7 at 9 cm. At 18 cm, the average CCCs were reduced to ~0.17 for GLCM and ~0.26 for GLRM. The non-stationary blurs are incorporated in radiomic features of cancellous bone, leading to inconsistencies in clustering of trabecular ROIs between different radial locations: an intersection-over-union overlap of corresponding (most similar) clusters between 0 cm and 9 cm shift was >70%, but dropped to <60% for the majority of corresponding clusters between 0 cm and 18 cm shift.

Conclusion

Non-stationary CT system blurs reduce inter-scan reproducibility of texture features of trabecular bone in UHR CT, especially for locations >15 cm from the isocenter. Radiomic models of bone quality derived from UHR CT measurements at isocenter might need to be revised before application in peripheral body sites such as the hips.

Serum B-cell activating factor and lung ultrasound B-lines in connective tissue disease related interstitial lung disease

OBJECTIVE

To investigate the role of serum B-cell activating factor (BAFF) and lung ultrasound (LUS) B-lines in connective tissue disease related interstitial lung disease (CTD-ILD), and their association with different ILD patterns on high resolution computed tomography (HRCT) of chest.

METHODS

We measured the levels of BAFF and KL-6 by ELISA in the sera of 63 CTD-ILD patients [26 with fibrotic ILD (F-ILD), 37 with non-fibrotic ILD (NF-ILD)], 30 CTD patients without ILD, and 26 healthy controls. All patients underwent chest HRCT and LUS examination.

RESULTS

Serum BAFF levels were significantly higher in CTD patients compared to healthy subjects (617.6 ± 288.1 pg/ml vs. 269.0 ± 60.4 pg/ml, p < 0.01). BAFF concentrations were significantly different between ILD group and non-ILD group (698.3 ± 627.4 pg/ml vs. 448.3 ± 188.6 pg/ml, p < 0.01). In patients with ILD, BAFF concentrations were significantly correlated with B-lines number (r = 0.37, 95% CI 0.13-0.56, p < 0.01), KL-6 level (r = 0.26, 95% CI 0.01-0.48, p < 0.05), and Warrick score (r = 0.33, 95% CI 0.09-0.53, p < 0.01), although all correlations were only low to moderate. B-lines number correlated with Warrick score (r = 0.65, 95% CI 0.48-0.78, p < 0.01), and KL-6 levels (r = 0.43, 95% CI 0.21-0.61, p < 0.01). Patients with F-ILD had higher serum BAFF concentrations (957.5 ± 811.0 pg/ml vs. 516.1 ± 357.5 pg/ml, p < 0.05), KL-6 levels (750.7 ± 759.0 U/ml vs. 432.5 ± 277.5 U/ml, p < 0.05), B-lines numbers (174.1 ± 82 vs. 52.3 ± 57.5, p < 0.01), and Warrick score (19.9 ± 4.6 vs. 13.6 ± 3.4, p < 0.01) vs. NF-ILD patients. The best cut-off values to separate F-ILD from NF-ILD using ROC curves were 408 pg/ml for BAFF (AUC = 0.73, p < 0.01), 367 U/ml for KL-6 (AUC = 0.72, p < 0.05), 122 for B-lines number (AUC = 0.89, p < 0.01), and 14 for Warrick score (AUC = 0.87, p < 0.01) respectively.

CONCLUSION

Serum BAFF levels and LUS B-lines number could be useful supportive biomarkers for detecting and evaluating the severity and/or subsets of CTD-ILD. If corroborated, combining imaging, serological, and sonographic biomarkers might be beneficial and comprehensive in management of CTD-ILD.

Demographic and clinico-radiological profile on High-Resolution Computerized Tomography (HRCT) thorax in mild or asymptomatic clinically suspected COVID-19 patients in high-endemicity area of India-Can HRCT be the first screening tool? -The DECRYPTION study

BACKGROUND

With COVID-19 cases rising, despite CT chest being of value in diagnosis and prognostication in COVID-19, its role in mild or asymptomatic suspected COVID-19, before RT-PCR test is lacking.

METHOD

This is a retrospective observational study involving asymptomatic or mildly symptomatic clinically suspected COVID-19 infection in a high endemicity area. Of 2532 HRCT chest database, 376 eligible cases were analyzed for clinico-radiological correlation for CT findings based CORADS and CT severity score between positive vs negative group.

RESULTS

Of 376, 186 (48.46%) had COVID-19 features on HRCT in mild and asymptomatic suspected patients. 98 (26.06%) had CO-RARDS - 5, 88 (23.40%) had CO-RADS - 4. 48 (12.76%), 128 (34.04%), 14 (3.72%) had CO-RADS score of 3,2,1, respectively. Positive CT findings were more likely beyond 3 days of symptoms compared to those presenting earlier {days: (Mean) 4.2 vs 2.76} Positive CT was significantly associated with patients with anosmia and dyspnea. The common presenting symptoms were Fever 196 (52.12%) and followed by sore throat in 173 (46.01%). The common HRCT findings were Ground glass opacity (GGO) (74.60%), followed by Lymphadenopathy (LN) (27.92%). LN which was more prevalent in symptomatic patients {99/343 (28.86%) vs {6/33 (18.18%)} asymptomatics (P: 0.04)}. Consolidation was significantly more in asymptomatics with COPD (P: 0.004). 6 (3.22%) patients had CT score >17/25.

CONCLUSION

Chest HRCT picked 48.46% positive cases in mildly symptomatic and asymptomatic patients of which 3.22% had severe involvement (>17). Being a noninvasive, rapid, sensitive, low risk of cross infection with high reproducibility, chest CT is worth evaluating as screening modality even in asymptomatic and mildly symptomatic clinically suspected COVID-19.

Application of a Novel Ultra-High Resolution Multi-Detector CT in Quantitative Imaging of Trabecular Microstructure

PURPOSE

To evaluate the performance of a novel ultra-high resolution multi-detector CT scanner (Canon Aquilion Precision UHR CT), capable of visualizing ~150 μm details, in quantitative assessment of bone microarchitecture. Compared to conventional CT, the spatial resolution of UHR CT begins to approach the size of the trabeculae. This might enable measurements of microstructural correlates of osteoporosis, osteoarthritis, and other bone disease.

METHODS

The UHR CT system features a 160-row x-ray detector with 250×250 μm pixels (measured at isocenter) and a custom-designed x-ray source with a 0.4×0.5 mm focal spot. Visualization of high contrast details down to ~150 μm has been achieved on this device, which is now commercially available for clinical use. To evaluate the performance of UHR CT in quantification of bone microstructure, we imaged a variety of human bone samples (including ulna, radius, and vertebrae) embedded in a ~16 cm diameter plastic cylinder and in an anthropomorphic thorax phantom (QRM-Thorax, QRM Gmbh). Helical UHR CT acquisitions (120 kVp tube voltage) were acquired at scan exposures of 375 mAs - 5 mAs. For comparison, the samples were also imaged using a Normal Resolution (NR) mode available on the scanner, involving 500 μm slice thickness, exposure of 50 mAs, and a focal spot of 0.6×1.3 mm. We obtained micro-CT (μCT) of the bone samples at ~28 μm voxel size as a gold-standard reference. Geometric measurements of bone microstructure were performed in 17 regions-of-interests (ROIs) distributed throughout the bones of the phantoms; image registration was used to place the ROIs at corresponding locations in the UHR CT and NR CT. Trabecular thickness Tb.Th, spacing Tb.Sp, and Bone Volume fraction BvTv were obtained. The UHR and NR imaging protocols were compared terms of correlations to μCT and error of trabecular measurements. The effect of dose on trabecular morphometry was also studied for the UHR CT. Furthermore, we evaluated the sensitivity of texture features of trabecular bone (recently proposed as an alternative to geometric indices of microstructure) to imaging protocol. Image texture evaluation was performed using ~150 regions of interest (ROIs) across all bone samples. Three-dimensional Gray Level Co-occurrence Matrix (GLCM) and Gray Level Run Length Matrix (GLRM) features were extracted for each ROI. We analyzed correlation and concordance correlation coefficient (CCC) of the mean ROI values of texture features obtained using the UHR and NR modes.

RESULTS

UHR CT reconstructions of bone samples clearly demonstrated improved visualization of the trabeculae compared to NR CT. UHR CT achieved substantially better correlations for all three metrics of bone microstructure, in particular for BvTv (correlation coefficient of 0.91 for UHR CT compared to 0.84 for NR CT) and TbSp (correlation of 0.74 for UHR CT and 0.047 for NR CT). The error obtained with UHR CT was generally smaller than that of NR CT. For TbSp, the mean deviation from μCT (averaged across all bone samples) was only ~0.07 for UHR CT, compared to 0.25 for NR CT. Analysis of reproducibility of texture features of trabecular bone between UHR CT and NR CT revealed fair correlations (>0.7) for the majority of GLCM features, but relatively poor CCC (e.g. 0.02 for Energy and 0.04 for Entropy). The magnitude of texture metrics is particularly affected by the enhanced spatial resolution of UHR CT.

CONCLUSION

The recently introduced UHR CT achieves improved correlation and reduced error in measurements of trabecular bone microstructure compared to conventional resolution CT. Future development of diagnostic strategies based on textural biomarkers derived from UHR CT will need to account for potential sensitivity of texture features to image resolution.

Functional and Objective Audiovestibular Evaluation of Children With Apparent Semicircular Canal Dehiscence-A Case Series in a Pediatric Vestibular Center

Semicircular canal dehiscence is a bony abnormality in the otic capsule especially involving the superior semicircular canal. Since its identification in 1998, there is significant research regarding the pathology in the adult population. This condition generates a third window effect that is well–described in the literature. However, the entity is rare in the pediatric population with limited research. Difficulties encountered in children are obtaining a direct history that is essential for the diagnosis followed by neurovestibular tests that may be difficult to perform. This study presents observations regarding different clinical and diagnostic aspects of semicircular canal dehiscences in children as a retrospective audit in a tertiary pediatric vestibular center. Of 580 children assessed in a 30 months period undergoing comprehensive functional and objective audiovestibular assessment, 13 children (2.2%) were detected to possess radiological semicircular canal dehiscences (high resolution computed tomography scans at 0.625 mm slices reformatted in the axial, coronal and sagittal planes). The right superior semicircular canal was most commonly affected (66.6%). There were 4 bilateral semicircular canal dehiscences. Clinical suspicion of the condition was raised with reliable surrogate history from carers or from older children (100%), a mixed or conductive hearing loss (80% of hearing losses) in the presence of normal impedance audiometry (92.3%), normal transient otoacoustic emissions (84.6%) on the side of the dehiscence and the presence of replicable pathological saccades in the video head impulse test (76.9%). Disequilibrium symptoms and typical third window symptoms were absent or difficult to elicit in children (46.15 and 30.76% respectively). Only 3 (0.5%) fulfilled the adult criteria of a superior semicircular canal dehiscence syndrome. The abnormal video head impulse test characterized by pathological saccades may affect other non-dehisced ipsilateral canals. Semicircular canal dehiscences are rare in children but may be considered as an etiology for hearing losses and imbalance. Children with semicircular canal dehiscence may present differently from the classical superior semicircular canal dehiscence syndrome found in adults.

[Application of technique of HRCT and multipliate plane reconstruction in analysis of image features of superior semicircular canal dehiscence]

Objective: Application of technique of high resolution CT (HRCT) and multipliate plane reconstruction, analyzed the image features of suspicious superior semicircular canal dehiscence (SSCD) to improve the understanding of the SSCD.Method:From January 2016 to April 2017, a total of 230 adult patients who checked temporal bone HRCT were collected in this retrospective study, of which 160 cases (320 ears) of the non-SSCD, 73 cases were male (146 ears), 87 cases were female (174 ears), aged 18 to 70 years old; 70 cases (113 ears) were suspicious diagnosed with SSCD, 33 cases were male (55 ears), 37 cases were female (58 ears), and 18 to 71 years old. The thin section CT scan of the temporal bone translocation was performed on all subjects, then the CT post processing workstation was used for multipliate plane reconstruction (MPR), and the main rows of coronal and oblique sagittal image reconstruction was performed. To observe, measure and record the HRCT features and datas of the suspicious SSCD and non-SSCD, then analyze the collected data.Result:There were 160 cases (320 ears) in non-SSCD group, and the height of the superior semicircular canal was (6.43±0.51)mm, the outer tube diameter was (0.83±0.13)mm, the thickness of the tympanic cavity was (2.19±0.62)mm, the anteroposterior diameter of mastoid was (14.55±1.98)mm; There were 70 cases (113 ears) in the suspicious SSCD group, the above results were (6.42±0.60)mm, (0.85±0.16)mm, (1.62±0.55)mm, (13.24±1.97)mm, respectively. Statistical analysis showed that there were no significant difference in the height of the superior semicircular canal (P=0.94) and the outer tube diameter (P=0.64), There were significant differences in the thickness of the tympanic cavity (P=0.002) and the anteroposterior diameter of mastoid (P=0.004). There were 70 cases (113 ears) in group suspicious SSCD, the unilateral defect had 27 cases (27 ears), and bilateral defect had 43 cases (86 ears). The defect was located in the middle of the parietal wall in 48 ears, located in the anterior wall of 20 ears, located in the posterior wall of 32 ears, more than two defects in 13 ears; 7 ears were mastoid pneumatic type, 90 ears were mastoid sclerotic type, 16 ears were mastoid mixed type.Conclusion:The SSCD was more common in the sclerotic mastoid. The bilateral defect was common, mostly located in the middle of the parietal wall. The occurrence of the lesion is not related to the height and diameter of the superior semicircular canal, but may be related to the thinning of the whole temporal bone.

Renal Stone Characterization using High Resolution Imaging Mode on a Photon Counting Detector CT System

In addition to the standard-resolution (SR) acquisition mode, a high-resolution (HR) mode is available on a research photon-counting-detector (PCD) whole-body CT system. In the HR mode each detector consists of a 2x2 array of 0.225 mm × 0.225 mm subpixel elements. This is in contrast to the SR mode that consists of a 4x4 array of the same sub-elements, and results in 0.25 mm isotropic resolution at iso-center for the HR mode. In this study, we quantified ex vivo the capabilities of the HR mode to characterize renal stones in terms of morphology and mineral composition. Forty pure stones - 10 uric acid (UA), 10 cystine (CYS), 10 calcium oxalate monohydrate (COM) and 10 apatite (APA) - and 14 mixed stones were placed in a 20 cm water phantom and scanned in HR mode, at radiation dose matched to that of routine dual-energy stone exams. Data from micro CT provided a reference for the quantification of morphology and mineral composition of the mixed stones. The area under the ROC curve was 1.0 for discriminating UA from CYS, 0.89 for CYS vs COM and 0.84 for COM vs APA. The root mean square error (RMSE) of the percent UA in mixed stones was 11.0% with a medium-sharp kernel and 15.6% with the sharpest kernel. The HR showed qualitatively accurate characterization of stone morphology relative to micro CT.

Pulmonary gas conducting interstitial pathway

In spite of the growing efforts oriented towards revealing different aspects of emphysema, the persistence of the emphysematous or emphysema-like changes (ELCs) is not explored yet in the open literature. In this study we demonstrate the persistence of an ELC for 22 years in a spontaneous pneumothorax (SP) patient which indicates a hitherto unknown gas supply to the ELC. For this purpose we used high resolution computed tomography (HRCT) images processed into three-dimensional (3D) geometry. By the same token, not only a long persistence but also the volume increase of this ELC between 2002 and 2010 was demonstrated. The 3D geometry visualized an aerated interstitial structure between the sites of supposed gas leakage at the wall of the third generation airways and the ELC. This potential gas conducting interstitial pathway is not a continuation and has neither the form nor the structure of a bronchus. The finding suggests that in this patient the intrabronchial gas passes through the bronchial wall and via a gas conducting interstitial pathway reaches the ELC. Despite the availability of the presently employed techniques for at least 15 years, such case and phenomenon have not been described previously. The retrieval of the patient suggests that the findings could be relevant for a considerable proportion of the population.

EDART, a discrete algebraic reconstructing technique for experimental data obtained with high resolution computed tomography

A novel reconstruction method is presented to improve the image quality of three dimensional (3D) datasets for samples consisting of only one material and surrounding air, obtained with high resolution X-ray Computed Tomography (μCT). It combines discrete tomography with iterative reconstruction algorithms, it is applicable for routine μCT applications and is referred to as the Experimental Discrete Algebraic Reconstruction Technique (EDART). A fast and intuitive method to estimate the attenuation coefficient and segmentation threshold, in case these are unknown, is included. Experimental results illustrate that EDART allows the improvement of the reconstruction quality as compared to standard iterative reconstruction when few projections are available, without significantly increasing the reconstruction time.

Pulmonary involvement in rheumatoid arthritis: multidetector computed tomography findings

BACKGROUND

Pulmonary involvement in rheumatoid arthritis (RA) is common and encompasses a large spectrum of disease with different treatment options and prognoses. Therefore, assessment of these patients with multidetector computed tomography (MDCT) is vital.

PURPOSE

To evaluate the MDCT pulmonary findings of patients with RA and to compare these findings with the clinical status.

MATERIAL AND METHODS

Chest MDCT scans of 85 patients with RA between 2006-2012 were assessed. One patient with a pulmonary infection was excluded from the study. MDCT findings and distribution of the CT findings were examined, and patients were classified according to the predominant CT pattern. The pulmonary function test (PFT) results and categories, demographic characteristics, and clinical status of some of the patients for whom the results were obtained were evaluated, and the CT findings, PFT results, demographic characteristics, and clinical status were compared.

RESULTS

The study group consisted of 20 men (mean age, 58.1 years ± 13.1; range, 15-77 years) and 64 women (mean age, 55.3 years ± 11.5; range, 30-84 years). The most frequent findings were nodules (78.6%) and pleural thickening (48.8%). The most common CT patterns were follicular bronchiolitis (FB) in 28 (33.3%) patients and nodular disease (ND) in 12 (14.3%) others. There was no statistically significant difference between the CT findings and PFT results, and no statistically significant difference was noted in the CT findings between symptomatic and asymptomatic patients. In addition, there were some patients who exhibited no symptoms and/or had abnormal PFT results but had abnormal CT findings.

CONCLUSION

Rheumatoid arthritis is associated with a high frequency of CT findings and CT patterns, with nodules and pleural thickening being the most common CT findings and FB and ND being the most common CT patterns. MDCT identification of patients with RA may be helpful in the evaluation of pulmonary disease, even in patients without symptoms and PFT abnormalities.

Role of HRCT in detection and characterization of pulmonary abnormalities in patients with febrile neutropenia

Background:

Fever is of grave concern in the management of patients with neutropenia with early detection of a focus of infection being the major goal. As lungs are the most common focus, chest imaging is of vital importance. This Institute Review Board approved prospective study was undertaken to assess the usefulness of high resolution computed tomography (HRCT) in early detection and characterization of pulmonary abnormalities in febrile neutropenia.

Materials and Methods:

A total of 104 consecutive patients (M:F:75:29, age range 11–66 years) with fever of 38.2°C or more with an absolute neutrophil count <500/μl underwent HRCT chest. HRCT diagnosis was compared with final diagnosis based on ancillary investigations.

Results:

HRCT could detect pulmonary abnormalities in 93 patients (89.4%) with air space consolidation being the predominant finding (n = 57), followed by ground-glass opacities (Ground glass opacity (GGO), n = 49) and nodules (n = 39). HRCT could correctly characterize the infective lesions in 76 patients (81.7%). Presence of random or pleural-based nodules >10 mm with or without surrounding GGO or cavitations was sensitive (95.23%) and specific (96.7%) for fungal infection, while small (1–4 mm) random or centrilobular nodules with tree-in-bud appearance was sensitive (90%) and highly specific (97.02%) for tuberculosis. Diagnosis of pyogenic infection based on presence of air-space consolidation, pleural effusion, GGO or centrilobular nodules showed a sensitivity of 84.78% and specificity of 93.84%, whereas patchy or diffuse GGO, interstitial thickening and/or air-space consolidation showed high sensitivity (86.7%) and specificity (96.8%) for Pneumocystis jiroveci pneumonia.

Conclusion:

HRCT chest is an excellent modality in the diagnostic work-up of patients with febrile neutropenia allowing early detection and characterization of pulmonary abnormalities.