Kyung Jin Nam

Computed tomography findings of influenza A (H1N1) pneumonia in adults: pattern analysis and prognostic comparisons.

Aim The aim of this study was to evaluate retrospectively the chest computed tomography findings of influenza A (H1N1) pneumonia and their relationship with clinical outcome. Methods Chest computed tomography findings and clinical outcomes of 76 patients with influenza A (H1N1) pneumonia were assessed. Computed tomography findings were evaluated for the presence and distribution of parenchymal abnormalities, which were then classified into 3 patterns: bronchopneumonia, cryptogenic organizing pneumonia (COP), and acute interstitial pneumonia (AIP) patterns. Clinical courses were divided into 2 groups on the basis of necessitating admission to intensive care unit or mechanical ventilation therapy (group 1) or not (group 2). Results Lung abnormalities consisted of ground-glass opacity (93%, 71 patients), consolidation (66%, 50 patients), small nodules (61%, 46 patients), and tree-in-bud sign (22%, 17 patients). Lesions were classified into bronchopneumonia (49%, 37 patients), COP (30%, 23 patients), AIP (18%, 14 patients), and unclassifiable (3%, 2 patients) patterns. Patients with AIP pattern had a tendency to belonging to group 1, accounting for 40% (8 of 20 patients) of group 1 course and only 11% (6 of 56 patients) of group 2 course (P = 0.004). Conclusions Computed tomography findings of influenza A (H1N1) pneumonia in adults can be classified into COP, AIP, and bronchopneumonia patterns. Patients presenting with AIP pattern have a tendency to show poor prognosis.

Chronic destructive pulmonary tuberculosis: assessment of disease activity by computed tomography.

Background Determination of disease activity of chronic destructive pulmonary tuberculosis (TB) on imaging studies can be difficult because several imaging findings due to disease chronicity such as a residual cavity can be misinterpreted as an active disease. Purpose To evaluate computed tomography (CT) findings to predict active disease in patients with chronic destructive pulmonary TB. Material and Methods CT findings of 36 patients with chronic active destructive pulmonary TB and 78 patients with chronic inactive destructive pulmonary TB were reviewed and their patterns of lung lesions were compared. Statistical comparisons were performed using chi-square and Students T tests for univariate analyses, and a stepwise logistic regression method was used for multivariate analysis. Results Based on univariate analyses, cavitary destruction (P = 0.015), non-branching centrilobular nodules (P < 0.001), tree-in-bud pattern (P < 0.001), airspace nodules (P < 0.001), and cavities in other lobes (P = 0.001) were more frequently seen in chronic active destructive pulmonary TB. A stepwise logistic regression analysis demonstrated that tree-in-bud pattern (odds ratio, 52.3; 95% confidence interval, 6.2-437.2; P < 0.001) were significant CT findings associated with active disease. Conclusion Tree-in-bud pattern were the most characteristic CT findings to predict active disease in patients with chronic destructive pulmonary TB.

Image quality of CT angiography in young children with congenital heart disease: a comparison between the sinogram-affirmed iterative reconstruction (SAFIRE) and advanced modelled iterative reconstruction (ADMIRE) algorithms

AIM To compare the image quality of computed tomography angiography (CTA) reconstructed by sinogram-affirmed iterative reconstruction (SAFIRE) with that of advanced modelled iterative reconstruction (ADMIRE) in children with congenital heart disease (CHD). MATERIAL AND METHODS Thirty-one children (8.23±13.92 months) with CHD who underwent CTA were enrolled. Images were reconstructed using SAFIRE (strength 5) and ADMIRE (strength 5). Objective image qualities (attenuation, noise) were measured in the great vessels and heart chambers. Two radiologists independently calculated the contrast-to-noise ratio (CNR) by measuring the intensity and noise of the myocardial walls. Subjective noise, diagnostic confidence, and sharpness at the level prior to the first branch of the main pulmonary artery were also graded by the two radiologists independently. RESULTS The objective image noise of ADMIRE was significantly lower than that of SAFIRE in the right atrium, right ventricle, and myocardial wall (p<0.05); however, there were no significant differences observed in the attenuations among the four chambers and great vessels, except in the pulmonary arteries (p>0.05). The mean CNR values were 21.56±10.80 for ADMIRE and 18.21±6.98 for SAFIRE, which were significantly different (p<0.05). In addition, the diagnostic confidence of ADMIRE was significantly lower than that of SAFIRE (p<0.05), while the subjective image noise and sharpness of ADMIRE were not significantly different (p>0.05). CONCLUSION CTA using ADMIRE was superior to SAFIRE when comparing the objective and subjective image quality in children with CHD.

Image quality and radiation dose of CT venography with double dose reduction using model based iterative reconstruction: comparison with conventional CT venography using filtered back projection:

Background Computed tomography venography (CTV) at low kVp using model-based iterative reconstruction (MBIR) can enhance vascular enhancement with noise reduction. Purpose To evaluate image qualities and radiation doses of CTV at 80 kVp using MBIR and a small iodine contrast media (CM) dose and to compare these with those of CTV performed using a conventional protocol. Material and Methods Sixty-five patients (mean age = 58.1 ± 7.2 years) that underwent CTV for the evaluation of deep vein thrombosis (DVT) and varicose veins were enrolled in this study. Patients were divided into two groups: Group A (35 patients, 80 kVp, MBIR, automatic tube current modulation, CM = 270 mg/mL, 100 mL) and Group B (30 patients, 100 kVp, filtered back projection [FBP], 120 fixed mA, CM = 370 mg/mL, 120 mL). Objective and subjective image qualities of inferior vena cava (IVC), femoral vein (FV), and popliteal vein (PV) were assessed and radiation doses were recorded. Results Mean vascular enhancement in group A was significantly lower than in group B (P < 0.01). Noise in group A was significantly lower than in group B except for PV and contrast-to-noise ratio were not significantly different in the two groups (P > 0.05). In addition, radiation dose in group A was significantly lower than in group B (P < 0.001). Subjective image quality comparison revealed group A was statistically inferior to group B except for subjective image noise. Conclusion CTV at 80 kVp using MBIR with small iodine contrast dose provided acceptable image quality at a lower radiation dose than conventional CTV using FBP.

Diagnostic performance and radiation dose of lower extremity CT angiography using a 128-slice dual source CT at 80 kVp and high pitch

Background Multi-detector computed tomography (MDCT) angiography is now used for the diagnosing patients with peripheral arterial disease. The dose of radiation is related to variable factors, such as tube current, tube voltage, and helical pitch. Purpose To assess the diagnostic performance and radiation dose of lower extremity CT angiography (CTA) using a 128-slice dual source CT at 80 kVp and high pitch in patients with critical limb ischemia (CLI). Material and Methods Twenty-eight patients (mean, 64.1 years; range, 39–80 years) with CLI were enrolled in this retrospective study and underwent CTA using a 128-slice dual source CT at 80 kVp and high pitch and subsequent intra-arterial digital subtraction angiography (DSA), which was used as a reference standard for assessing diagnostic performance. Results For arterial segments with significant disease (>50% stenosis), overall sensitivity, specificity, and accuracy of lower extremity CTA were 94.8% (95% CI, 91.7–98.0%), 91.5% (95% CI, 87.7–95.2%), and 93.1% (95% CI, 90.6–95.6%), respectively, and its positive and negative predictive values were 91.0% (95% CI, 87.1–95.0%), and 95.1% (95% CI, 92.1–98.1%), respectively. Mean radiation dose delivered to lower extremities was 266.6 mGy.cm. Conclusion Lower extremity CTA using a 128-slice dual source CT at 80 kVp and high pitch was found to have good diagnostic performance for the assessment of patients with CLI using an extremely low radiation dose.

Patterns of malignant non-mass enhancement on 3-T breast MRI help predict invasiveness: using the BI-RADS lexicon fifth edition

Background Non-mass enhancements (NME) with invasive components account for 10–42% of total malignant NMEs. The factors associated with invasiveness on magnetic resonance imaging (MRI) could be useful for clinical assessment and treatment. Purpose To evaluate the clinical significances of the distributions and internal enhancement patterns (IEP) of malignant NMEs on 3-T breast MRI. Material and Methods A total of 448 consecutive women with newly diagnosed breast cancer that had undergone preoperative MRI and surgery between February 2013 and March 2016 were identified. After exclusions, 72 malignant NMEs without a mass in 72 women (mean age = 51.5 years) were included. Two readers independently assessed distributions and IEPs of NME, according to the Breast Imaging Reporting and Data System lexicon fifth edition. Collected data included the presence of invasion and histopathologic factors. Results A clustered ring IEP was significantly associated with invasive cancer (75.0%, P = 0.001, Reader1; 72.9%, P < 0.001, Reader 2), absence of necrosis (79.0%, P < 0.001; 72.1%, P < 0.001, respectively), and high Ki-67 expression (74.2%, P = 0.048; 74.2%, P = 0.003, respectively). A clumped IEP was related to ductal carcinoma in situ (33.3%, P = 0.025; 50.0%, P = 0.001, respectively), absence of lymph node metastasis (24.1%, P = 0.029; 31.5%, P = 0.030, respectively), and presence of necrosis (34.5%, P = 0.003; 44.8%, P = 0.001, respectively). Conclusion The presence of a clustered ring IEP in patients with breast cancer was found to be significantly associated with invasive breast cancer and high Ki-67 expression.

Stereotactic vacuum-assisted breast biopsy under lateral decubitus position

Purpose Stereotactic vacuum-assisted breast biopsy (VAB) has been established as a standard method for histological diagnosis of microcalcification or nonpalpable breast lesions on mammography. Generally, the procedure has been done under the prone position or upright sitting position. We herein attempt to evaluate clinical utility of Stereotactic VAB under lateral decubitus position. Methods One hundred six women (mean age, 51.2 years) with mammographically detected microcalcification underwent lateral decubitus positioning VAB using the 8G probe. In all cases, we obtained mammography specimens for identification of microcalcification and postprocedure mammography. We reviewed mean procedure time, pieces of specimen, pathology and follow-up mammography. Results The procedure took approximately 20 minutes (range, 15-24 minutes). Average number of obtained specimens was 8.5 pieces (range, 6-12 pieces). Microcalcifications were confirmed in both specimen mammography and microscopic slides. Of 106 cases, 10 cases were diagnosed as ductal carcinoma in situ. Additional surgical management was performed. Atypical ductal hyperplasias were found in 8 cases, and fibrocystic changes in 88 cases. Conclusion Stereotactic VAB using the 8G probe under lateral decubitus position does not need a dedicated table, and is easier to maintain the position. Also, this procedure is accurate and safe. Thus, stereotactic VAB using the 8G probe under lateral decubitus position will be a useful method for diagnosis of microcalcification or nonpalpable breast lesions on mammography.