Machine learning-based computer-aided simple triage (CAST) for COVID-19 pneumonia as compared with triage by board-certified chest radiologists.

PURPOSE: Several reporting systems have been proposed for providing standardized language and diagnostic categories aiming for expressing the likelihood that lung abnormalities on CT images represent COVID-19. We developed a machine learning (ML)-based CT texture analysis software for simple triage based on the RSNA Expert Consensus Statement system. The purpose of this study was to conduct a multi-center and multi-reader study to determine the capability of ML-based computer-aided simple triage (CAST) software based on RSNA expert consensus statements for diagnosis of COVID-19 pneumonia. METHODS: For this multi-center study, 174 cases who had undergone CT and polymerase chain reaction (PCR) tests for COVID-19 were retrospectively included. Their CT data were then assessed by CAST and consensus from three board-certified chest radiologists, after which all cases were classified as either positive or negative. Diagnostic performance was then compared by McNemar's test. To determine radiological finding evaluation capability of CAST, three other board-certified chest radiologists assessed CAST results for radiological findings into five criteria. Finally, accuracies of all radiological evaluations were compared by McNemar's test. RESULTS: A comparison of diagnosis for COVID-19 pneumonia based on RT-PCR results for cases with COVID-19 pneumonia findings on CT showed no significant difference of diagnostic performance between ML-based CAST software and consensus evaluation (p > 0.05). Comparison of agreement on accuracy for all radiological finding evaluations showed that emphysema evaluation accuracy for investigator A (AC = 91.7%) was significantly lower than that for investigators B (100%, p = 0.0009) and C (100%, p = 0.0009). CONCLUSION: This multi-center study shows COVID-19 pneumonia triage by CAST can be considered at least as valid as that by chest expert radiologists and may be capable for playing as useful a complementary role for management of suspected COVID-19 pneumonia patients as well as the RT-PCR test in routine clinical practice.

Efficacy and safety of isavuconazole against deep-seated mycoses: A phase 3, randomized, open-label study in Japan.

OBJECTIVES: Isavuconazole is a convenient triazole antifungal agent with a broad antifungal spectrum. A randomized, open-label study (ClinicalTrials.gov, NCT03471988) was conducted to evaluate the efficacy and safety of isavuconazole in Japanese patients with deep-seated mycoses. PATIENTS AND METHODS: In Cohort A, patients with aspergillosis (chronic pulmonary aspergillosis and invasive aspergillosis) were randomized in a 2:1 ratio to isavuconazole or voriconazole, and in Cohort B, patients with cryptococcosis and mucormycosis were assigned to isavuconazole for up to 84 days of treatment. The overall outcome was evaluated according to the clinical, radiological, and mycological responses at Days 42 and 84 and at the end of treatment (EOT). RESULTS: A total of 103 participants were enrolled and received the study drug. The overall response rate of patients with chronic pulmonary aspergillosis in the isavuconazole (52 patients) and voriconazole (27 patients) groups was 82.7% and 77.8% at EOT, respectively. The response rate in patients with cryptococcosis (10 patients, isavuconazole group only) was 90.0%. One of three participants with invasive aspergillosis and one of three participants with mucormycosis responded in the isavuconazole group. In the safety evaluation, the incidence of adverse events in participants with chronic pulmonary aspergillosis was similar in both groups. Adverse drug reactions were reported in 32 (61.5%) patients receiving isavuconazole and 23 (85.2%) patients receiving voriconazole. CONCLUSIONS: Isavuconazole showed efficacy and safety in Japanese patients with chronic pulmonary aspergillosis and cryptococcosis, for which the drug is not currently indicated.

The scab-like sign: A CT finding indicative of haemoptysis in patients with chronic pulmonary aspergillosis?

OBJECTIVES: The aim of this study was to assess the CT findings that characterise haemoptysis in patients with chronic pulmonary aspergillosis (CPA). METHODS: We retrospectively identified 120 consecutive patients with CPA (84 men and 36 women, 17-89 years of age, mean age 68.4 years) who had undergone a total of 829 CT examinations between January 2007 and February 2017. In the 11 patients who underwent surgical resection, CT images were compared with the pathological results. RESULTS: The scab-like sign was seen on 142 of the 829 CT scans, specifically, in 87 of the 90 CT scans for haemoptysis and in 55 of the 739 CT scans obtained during therapy evaluation. In 48 of those 55 patients, haemoptysis occurred within 55 days (mean 12.0 days) after the CT scan. In the 687 CT scans with no scab-like sign, there were only three instances of subsequent haemoptysis in the respective patients over the following 6 months. Patients with and without scab-like sign differed significantly in the frequency of haemoptysis occurring after a CT scan (p<0.0001). Pathologically, the scab-like sign corresponded to a fibrinopurulent mass or blood crust. CONCLUSIONS: The scab-like sign should be considered as a CT finding indicative of haemoptysis. KEY POINTS: • Haemoptysis is commonly found in patients with CPA. • A CT finding indicative of haemoptysis in CPA patients is described. • Scab-like sign may identify CPA patients at higher risk of haemoptysis.

Comparison of computer-aided detection (CADe) capability for pulmonary nodules among standard-, reduced- and ultra-low-dose CTs with and without hybrid type iterative reconstruction technique.

PURPOSE: To directly compare the effect of a reconstruction algorithm on nodule detection capability of the computer-aided detection (CADe) system using standard-dose, reduced-dose and ultra-low dose chest CTs with and without adaptive iterative dose reduction 3D (AIDR 3D). MATERIALS AND METHODS: Our institutional review board approved this study, and written informed consent was obtained from each patient. Standard-, reduced- and ultra-low-dose chest CTs (250 mA, 50 mA and 10 mA) were used to examine 40 patients, 21 males (mean age ±â€¯standard deviation: 63.1 ±â€¯11.0 years) and 19 females (mean age, 65.1 ±â€¯12.7 years), and reconstructed as 1 mm-thick sections. Detection of nodule equal to more than 4 mm in dimeter was automatically performed by our proprietary CADe software. The utility of iterative reconstruction method for improving nodule detection capability, sensitivity and false positive rate (/case) of the CADe system using all protocols were compared by means of McNemar's test or signed rank test. RESULTS: Sensitivity (SE: 0.43) and false-positive rate (FPR: 7.88) of ultra-low-dose CT without AIDR 3D was significantly inferior to those of standard-dose CTs (with AIDR 3D: SE, 0.78, p < .0001, FPR, 3.05, p < .0001; and without AIDR 3D: SE, 0.80, p < .0001, FPR: 2.63, p < .0001), reduced-dose CTs (with AIDR 3D: SE, 0.81, p < .0001, FPR, 3.05, p < .0001; and without AIDR 3D: SE, 0.62, p < .0001, FPR: 2.95, p < .0001) and ultra-low-dose CT with AIDR 3D (SE, 0.79, p < .0001, FPR, 4.88, p = .0001). CONCLUSION: The AIDR 3D has a significant positive effect on nodule detection capability of the CADe system even when radiation dose is reduced.

Chest High-resolution Computed Tomography Findings in 601 Patients with Inflammatory Bowel Diseases.

RATIONALE AND OBJECTIVES: Pulmonary involvement in inflammatory bowel disease may reflect the common embryonic origin of the gastrointestinal tract and the bronchial tree. No studies have compared pulmonary high-resolution computed tomography (HRCT) findings between ulcerative colitis (UC) and Crohn disease (CD). This study aimed to assess the relationship between pulmonary HRCT findings and inflammatory bowel disease activity and to compare HRCT findings between UC and CD. MATERIALS AND METHODS: We retrospectively identified 601 consecutive patients (350 with UC and 251 with CD) who had undergone chest HRCT examinations at our institutions between April 2004 and April 2016. Parenchymal abnormalities, enlarged lymph nodes, and pleural effusion were evaluated on HRCT. RESULTS: One hundred sixty-seven patients (94 men, 73 women; aged 12-86 years, mean: 47.2 years) with UC and 93 patients (61 men, 32 women; aged 12-71 years, mean: 37.9 years) with CD had abnormal findings on chest HRCT. The HRCT findings of UC and CD mainly consisted of centrilobular nodules (in 49.1% and 45.2% of cases, respectively) and bronchial wall thickening (in 31.7% and 54.8%, respectively). There was no relationship between HRCT findings and disease activity. Bronchial wall thickening was significantly more frequent in patients with CD than in those with UC (P < .001). CONCLUSION: The main chest HRCT findings in UC and CD are centrilobular nodules and bronchial wall thickening. There are differences in HRCT findings between UC and CD.

Computed tomography findings in Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (DLBCL) of the elderly: comparison with EBV-negative DLBCL.

OBJECTIVE: This study aimed to compare CT findings in patients with Epstein-Barr virus positive (EBV+) diffuse large B-cell lymphoma (DLBCL) of the elderly with CT findings in patients with Epstein-Barr virus negative (EBV-) DLBCL. METHODS: We retrospectively identified 9 consecutive patients with EBV+ DLBCL (6 males and 3 females; aged 72-83 years, mean: 76.2 years) and 39 consecutive patients with EBV- DLBCL (19 males and 20 females; aged 53-91 years, mean: 71.3 years) who had undergone CT examinations between September 2007 and August 2016. In each type of disease, clinical and CT findings were evaluated. RESULTS: No significant differences in B symptom incidence or serum lactate dehydrogenase levels were found between the two diseases. However, the prognosis of patients with EBV+ DLBCL was significantly poorer than that of those with EBV- DLBCL (p < 0.05). Nodal and extranodal necrosis was found in 6 (66.7%) of 9 patients with EBV+ DLBCL and in 6 (15.4%) of 39 patients with EBV- DLBCL (p < 0.005). CONCLUSION: The CT finding of nodal and extranodal necrosis was significantly more frequent in patients with EBV+ DLBCL than in patients with EBV- DLBCL. Advances in knowledge: This is the first report on the CT findings in patients with EBV+ DLBCL of the elderly. Different CT findings are present in EBV+ DLBCL and EBV- DLBCL.

Disseminated Mycobacterium tuberculosis Infection Masquerading as Metastasis after Heavy Ion Radiotherapy for Prostate Cancer.

Fluorodeoxyglucose (FDG)-positron emission tomography with computed tomography (FDG-PET/CT) is useful in disease monitoring of malignancies after therapy, while an FDG uptake may also be present in benign diseases. We herein demonstrate a case of disseminated Mycobacterium tuberculosis mimicking systemic metastasis of prostate cancer. This case highlights that clinicians should consider Mycobacterium tuberculosis in patients with prostate cancer who demonstrate multifocal FDG uptakes masquerading as metastasis, even when the chest photographs reveal a normal appearance and a sputum examination demonstrates negative results. An invasive surgical biopsy may be required and a pathological analysis would be critical in the diagnosis of Mycobacterium tuberculosis.

High-resolution Computed Tomography Findings in Patients with Pulmonary Nocardiosis.

RATIONALE AND OBJECTIVES: Nocardiosis is difficult to diagnose, and the diagnosis is thus frequently delayed. High-resolution computed tomography (HRCT) findings of patients with pulmonary nocardiosis have been documented in few reports. Our study objective was to assess HRCT findings of patients with pulmonary nocardiosis. MATERIALS AND METHODS: This was a retrospective study of 20 consecutive patients with pulmonary Nocardia infections who underwent HRCT of the chest at our institutions from January 2011 to August 2014. After the exclusion of two patients with concurrent infections, the study group comprised 18 patients (11 men, 7 women; age range, 39-83 years; mean, 67.9 years) with pulmonary Nocardia infections. Parenchymal abnormalities, enlarged lymph nodes, and pleural effusion were evaluated on HRCT. RESULTS: Underlying conditions included respiratory disease (n = 6, 33.3%), collagen diseases (n = 5, 27.8%), and diabetes mellitus (n = 4, 22.2%). All patients showed abnormal HRCT findings, including the presence of a nodule/mass (n = 17, 94.4%), ground-glass opacity (n = 14, 77.8%), interlobular septal thickening (n = 14, 77.8%), and cavitation (n = 12, 66.7%). Pleural effusion was seen in two patients. There were no cases of lymph node enlargement. CONCLUSIONS: Among the HRCT findings in patients with pneumonia, a nodule/mass with interlobular septal thickening and/or cavitation are suggestive of pulmonary nocardiosis.

Chest HRCT findings in acute transformation of adult T-cell lymphoma/leukemia.

OBJECTIVES: To assess chest high-resolution computed tomography (HRCT) findings in patients with acute transformation of adult T cell leukaemia/lymphoma (ATLL). METHODS: We retrospectively identified 72 consecutive patients at our institution with ATLL between October 2000 and March 2014. The cases included acute type (n = 20), lymphoma type (n = 21), smouldering type (n = 24) and chronic type (n = 7). Sixteen (7 men, 9 women; aged 36-85 years, mean 63.3 years) of 31 patients (24 with smouldering and seven with chronic type; 51.6 %) developed acute transformation of ATLL, and had undergone chest HRCT examinations. Parenchymal abnormalities, enlarged lymph nodes, pericardial effusion, pleural effusion and skin lesions were evaluated on HRCT. RESULTS: Chest HRCT of 15 of the 16 patients showed abnormal findings, including ground-glass opacity (GGO) (n = 8), consolidation (n = 5), interlobular septal thickening (n = 5) and nodules (n = 5). Pleural effusion was found in five patients, lymph node enlargement in 10 patients and multiple skin thickening in two patients. CONCLUSIONS: Almost all patients with acute transformation of ATLL had abnormal findings on chest HRCT, which consisted mainly of lymph node enlargement, GGO, interlobular septal thickening, nodules and bilateral pleural effusions. KEY POINTS: • The recognition of CT findings of acute transformation is important • Almost all patients with acute transformation have abnormal findings on HRCT • Characteristic CT features are present in acute transformation of indolent ATLL.

Expiratory computed tomographic techniques: a cause of a poor rate of change in lung volume.

Ninety-nine patients (29 males and 70 females; mean age, 57.1 years; range, 22-81 years) were included in this study to evaluate the factors affecting smaller lung volume changes in expiratory high-resolution computed tomography performed to depict air trapping. All patients underwent inspiratory and expiratory chest thin-section CT examinations and pulmonary function tests. Air trapping on CT images was graded subjectively. All variables (age, sex, diagnosis, pulmonary function index, and air trapping score) were compared with the degree of change in lung volume between the inspiratory and expiratory CT examinations. The variables affecting a lower degree of volume change were vital capacity, forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and the FEV1.0/FVC ratio. Bronchiolitis obliterans was the dominant diagnosis in patients with insufficient degrees of breath holding and in patients with negative air trapping scores despite an abnormal air trapping index. An insufficient degree of lung changes between inspiration and expiration on CT examinations represented bronchiolitis obliterans, which resulted in low FEV1.0 and FEV1.0/FVC values. Changes in the time gap from the announcement of exhalation and breath holding to the start of scanning most effectively indicated air trapping in patients with bronchiolar disorders.

A comparison of axial versus coronal image viewing in computer-aided detection of lung nodules on CT.

PURPOSE: To compare primarily viewing axial images (Axial mode) versus coronal reconstruction images (Coronal mode) in computer-aided detection (CAD) of lung nodules on multidetector computed tomography (CT) in terms of detection performance and reading time. MATERIALS AND METHODS: Sixty CT data sets from two institutions were collected prospectively. Ten observers (6 radiologists, 4 pulmonologists) with varying degrees of experience interpreted the data sets using CAD as a second reader (performing nodule detection first without then with aid). The data sets were interpreted twice, once each for Axial and Coronal modes, in two sessions held 4 weeks apart. Jackknife free-response receiver-operating characteristic analysis was used to compare detection performances in the two modes. RESULTS: Mean figure-of-merit values with and without aid were 0.717 and 0.684 in Axial mode and 0.702 and 0.671 in Coronal mode; use of CAD significantly increased the performance of observers in both modes (P < 0.01). Mean reading times for radiologists did not significantly differ between Axial (156 ± 74 s) and Coronal mode (164 ± 69 s; P = 0.08). Mean reading times for pulmonologists were significantly lower in Coronal (112 ± 53 s) than in Axial mode (130 ± 80 s; P < 0.01). CONCLUSION: There was no statistically significant difference between Axial and Coronal modes for lung nodule detection with CAD.

Comparison of high-resolution computed tomography findings between Pseudomonas aeruginosa pneumonia and Cytomegalovirus pneumonia.

OBJECTIVE: To compare pulmonary high-resolution CT (HRCT) findings in patients with Pseudomonas aeruginosa pneumonia to HRCT findings in patients with Cytomegalovirus (CMV) pneumonia. METHODS: We studied 124 patients (77 men, 47 women; age range, 20-89 years; mean age, 65.4 years) with P. aeruginosa pneumonia and 44 patients (22 men, 22 women; age range, 36-86 years; mean age, 63.2 years) with CMV pneumonia. RESULTS: CT findings of consolidation (p < 0.005), bronchial wall thickening (p < 0.001), cavity (p < 0.05), and pleural effusion (p < 0.001) were significantly more frequent in patients with P. aeruginosa pneumonia than in those with CMV pneumonia. Centrilobular nodules, a crazy-paving appearance, and nodules were significantly more frequent in patients with CMV pneumonia than in those with P. aeruginosa pneumonia (all p < 0.001). CONCLUSION: Pulmonary HRCT findings, such as bronchial wall thickening, crazy-paving appearance, and nodules may be useful in distinguishing between P. aeruginosa pneumonia and CMV pneumonia. KEY POINTS: Distinguishing Pseudomonas aeruginosa pneumonia from Cytomegalovirus pneumonia is important. Characteristic features of underlying conditions are present in each pneumonia species. Bronchial wall thickening and cavities are more frequent in Pseudomonas aeruginosa pneumonia. Nodules and a crazy-paving appearance are more frequent in Cytomegalovirus pneumonia.