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.

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.

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.