Radiomics analysis for differentiating of cervical lymphadenopathy between cancer of unknown primary and malignant lymphoma on unenhanced computed tomography.

To investigate the usefulness of texture analysis to discriminate between cervical lymph node (LN) metastasis from cancer of unknown primary (CUP) and cervical LN involvement of malignant lymphoma (ML) on unenhanced computed tomography (CT). Cervical LN metastases in 17 patients with CUP and cervical LN involvement in 17 patients with ML were assessed by 18F-FDG PET/CT. The texture features were obtained in the total cross-sectional area (CSA) of the targeted LN, following the contour of the largest cervical LN on unenhanced CT. Values for the max standardized uptake value (SUVmax) and the mean SUV value (SUVmean), and 34 texture features were compared using a Mann-Whitney U test. The diagnostic accuracy and area under the curve (AUC) of the combination of the texture features were evaluated by support vector machine (SVM) with nested cross-validation. The SUVmax and SUVmean did not differ significantly between cervical LN metastases from CUP and cervical LN involvement from ML. However, significant differences of 9 texture features of the total CSA were observed (p = 0.001 - 0.05). The best AUC value of 0.851 for the texture feature of the total CSA were obtained from the correlation in the gray-level co-occurrence matrix features. SVM had the best AUC and diagnostic accuracy of 0.930 and 84.8%. Radiomics analysis appears to be useful for differentiating cervical LN metastasis from CUP and cervical LN involvement of ML on unenhanced CT.

Kerley A-lines represent thickened septal plates between lung segments in patients with lymphangitic carcinomatosis: confirmation using 3D-CT lung segmentation analysis.

PURPOSE: Kerley A-lines are generally apparent in patients with pulmonary edema or lymphangitic carcinomatosis. There are two main thoughts regarding the etiology of Kerley A-lines, but no general agreement. Specifically, the lines are caused by thickened interlobular septa or dilated anastomotic lymphatics. Our purpose was to determine the anatomic structure represented as Kerley A-lines using 3D-CT lung segmentation analysis. MATERIALS AND METHODS: We reviewed 139 charts of patients with lymphangitic carcinomatosis of the lung who had CT and X-ray exams with a maximum interval of 7 days. The presence of Kerley A-lines on X-ray was assessed by a radiologist. The A-lines on X-ray were defined as follows: dense; fine (< 1 mm thick); ≥ 2 cm in length, radiating from the hilum; no bifurcation; and not adjacent to the pleura. For cases with Kerley A-lines on X-ray, three radiologists agreed that the lines on CT corresponded with Kerley A-lines. The incidence of A-lines and the characteristics of the lines were investigated. The septal lines between lung segments were identified using a 3D-CT lung segmentation analysis workstation. The percentage of agreement between the A-lines on CT and lung segmental lines was assessed. RESULTS: On chest X-ray, 37 Kerley A-lines (right, 16; left, 21) were identified in the 22 cases (16%). Of these, 4 lungs with 12 lines were excluded from analysis due to technical reasons. Nineteen of the 25 lines (76%) corresponded to the septal lines on CT. Of these, 11 lines matched with automatically segmented lines (intersegmental septa, 4; intersubsegmental septa, 7) by the workstation. Two lines (8%) represented fissures. Four lines corresponded to the bronchial wall/artery (3 lines, 12%) or vein (1 line, 4%). CONCLUSION: Kerley A-lines primarily represented thickened and continued interlobular septal lines that corresponded to the septa between lung segments and subsegments.

Preoperative CT Findings for Predicting Acute Exacerbation of Interstitial Pneumonia After Lung Cancer Surgery: A Multicenter Case-Control Study.

BACKGROUND. Acute exacerbation (AE) is a life-threatening complication of inter-stitial pneumonia (IP). Thoracic surgery may trigger AE. OBJECTIVE. The purpose of this study is to explore the role of preoperative CT findings in predicting postoperative AE in patients with IP and lung cancer. METHODS. This retrospective case-control study included patients from 22 institutions who had IP and underwent thoracic surgery for lung cancer. AE was diagnosed on the basis of symptoms and imaging findings noted within 30 days after surgery and the absence of alternate causes. For each patient with AE, two control patients without AE were identified. After exclusions, the study included 92 patients (78 men and 14 women; 31 with AE [the AE group] and 61 without AE [the no-AE group]; mean age, 72 years). Two radiologists independently reviewed preoperative thin-slice CT examinations for pulmonary findings and resolved differences by consensus. The AE and no-AE groups were compared using the Fisher exact and Mann-Whitney U tests. Multivariable logistic regression was performed. Interreader agreement was assessed by kappa coefficients. RESULTS. A total of 94% of patients in the AE group underwent segmentectomy or other surgery that was more extensive than wedge resection versus 75% in the no-AE group (p = .046). The usual IP pattern was present in 58% of the AE group versus 74% of the no-AE group (p = .16). According to subjective visual scoring, the mean (± SD) ground-glass opacity (GGO) extent was 6.3 ± 5.4 in the AE group versus 3.9 ± 3.8 in the no-AE group (p = .03), and the mean consolidation extent was 0.5 ± 1.2 in the AE group versus 0.1 ± 0.3 in the no-AE group (p = .009). Mean pulmonary trunk diameter was 28 ± 4 mm in the AE group versus 26 ± 3 mm in the no-AE group (p = .02). In a model of CT features only, independent predictors of AE (p < .05) were GGO extent (odds ratio [OR], 2.8), consolidation extent (OR, 9.4), and pulmonary trunk diameter (OR, 4.2); this model achieved an AUC of 0.75, a PPV of 71%, and an NPV of 77% for AE. When CT and clinical variables were combined, undergoing segmentectomy or more extensive surgery also independently predicted AE (OR, 8.2; p = .02). CONCLUSION. The presence of GGO, consolidation, and pulmonary trunk enlargement on preoperative CT predicts AE in patients with IP who are undergoing lung cancer surgery. CLINICAL IMPACT. Patients with IP and lung cancer should be carefully managed when predictive CT features are present. Wedge resection, if possible, may help reduce the risk of AE in these patients. TRIAL REGISTRATION. University Hospital Medical Information Clinical Trial Registry UMIN000029661.

Unenhanced CT texture analysis with machine learning for differentiating between nasopharyngeal cancer and nasopharyngeal malignant lymphoma.

Differentiating between nasopharyngeal cancer and nasopharyngeal malignant lymphoma (ML) remains challenging on cross-sectional images. The aim of this study is to investigate the usefulness of texture features on unenhanced CT for differentiating between nasopharyngeal cancer and nasopharyngeal ML. Thirty patients with nasopharyngeal tumors, including 17 nasopharyngeal cancers and 13 nasopharyngeal MLs, were underwent 18F-FDG PET/CT. All nasopharyngeal cancers and 7 of 13 nasopharyngeal MLs were confirmed by endoscopic biopsy. On unenhanced CT, 34 texture features were analyzed following lesion segmentation in the maximum area of the target lesion. The Mann-Whitney U test and areas under the curve (AUCs) were used for analysis and to compare the maximum standardized uptake values (SUV)max, SUVmean, and 34 texture features. A support vector machine (SVM) was constructed to evaluate the diagnostic accuracy and AUCs of combinations of texture features, with 50 repetitions of 5-fold cross-validation. Differences between the SUVmax and SUVmean for nasopharyngeal cancers and nasopharyngeal MLs were not significant. Significant differences of texture features were seen, as follows: 1 histogram feature (p = 0.038), 3 gray-level co-occurrence matrix features (p < 0.05), and 1 neighborhood gray-level different matrix feature (NGLDM) (p = 0.003). Coarseness in NGLDM provided the highest diagnostic accuracy and largest AUC of 76.7% and 0.82, respectively. SVM evaluation of the combined texture features obtained the highest accuracy of 81.3%, with an AUC of 0.80. Combined texture features can provide useful information for discriminating between nasopharyngeal cancer and nasopharyngeal ML on unenhanced CT.

Automatic bronchial segmentation on ultra-HRCT scans: advantage of the 1024-matrix size with 0.25-mm slice thickness reconstruction.

PURPOSE: The aim of this study was to evaluate the advantages of ultra-high-resolution computed tomography (U-HRCT) for automatic bronchial segmentation. MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board, and written informed consent was waived. Thirty-three consecutive patients who underwent chest CT by a U-HRCT scanner were enrolled. In each patient, CT data were reconstructed by two different protocols: 512 × 512 matrix with 0.5-mm slice thickness (conventional HRCT mode) and 1024 × 1024 matrix with 0.25-mm slice thickness (U-HRCT mode). We used a research workstation to compare the two CT modes with regard to the numbers and total lengths of the automatically segmented bronchi. RESULTS: Significantly greater numbers and longer lengths of peripheral bronchi were segmented in the U-HRCT mode than in the conventional HRCT mode (P < 0.001, for fifth- to eighth-generation bronchi). For example, the mean numbers and total lengths of the sixth-generation bronchi were 81 and 1048 mm in the U-HRCT mode and 59 and 538 mm in the conventional HRCT mode. CONCLUSIONS: The U-HRCT mode greatly improves automatic airway segmentation for the more peripheral bronchi, compared with the conventional HRCT mode. This advantage can be applied to routine clinical care, such as virtual bronchoscopy and automatic lung segmentation.

CT radiomics analysis of lung cancers: Differentiation of squamous cell carcinoma from adenocarcinoma, a correlative study with FDG uptake.

BACKGROUND AND PURPOSE: Pulmonary squamous cell carcinoma (SCC) was reported to have significantly higher histogram_kurtosis obtained by unenhanced computed tomography (CT) and a greater maximum standardized uptake value (SUVmax) determined by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) than pulmonary adenocarcinoma (AD). The first study aim was to investigate whether CT radiomics features could differentiate SCC from AD. The second aim was to investigate correlations between CT radiomics features and SUVmax. MATERIALS AND METHODS: Forty solid lung tumors < 3 cm in diameter pathologically proven to be SCC (n = 18) or AD (n = 22) were included. The SUVmax was determined by 18F-FDG-PET/CT and 42 CT radiomics features were obtained from unenhanced CT. A Mann-Whitney U test was used to compare the SUVmax and each CT radiomics feature to differentiate SCC from AD. The area under the curve (AUC) was calculated from receiver operating characteristic (ROC) analysis. A binary logistic regression analysis was performed for a combination of SUVmax with each CT radiomics feature. A Spearman rank correlation analysis was performed to determine correlations between SUVmax and CT radiomics features. RESULTS: Twenty-six of 42 CT radiomics features were significantly different between groups. The best AUC of the CT radiomics features was 0.81 for both the GLRLM_SRHGE and GLZLM_HGZE. The AUC value improved when the shape_sphericity feature was combined with SUVmax (AUC = 0.92). The CT radiomics features exhibiting strongest correlations with the SUVmax were different in both AD and SCC groups. CONCLUSION: CT radiomics features correlated with tumor structural characteristics of SCC and AD, and were closely related to metabolic information from FDG-PET/CT.

Analysis of bronchoalveolar lavage samples collected from 30 patients with drug-induced pneumonitis.

BACKGROUND: Drug-induced pneumonitis is a disease encountered by pulmonologists in the clinical setting. The diagnosis generally considers the patient's clinical course and the results of peripheral blood tests, radiological examinations, and often bronchoscopic examinations. However, few studies have reported the association between radiological patterns such as ground-glass opacity (GGO) or consolidation, and bronchoalveolar lavage fluid (BALF) cell fractions. This study aimed to clarify this association. METHODS: Patients with a Naranjo's score of probable or definite were enrolled, and all 30 patients were categorized under probable. Data such as patient background, blood examination results, radiological findings, and BALF cell fractions were retrospectively collected. The association between BALF cell fractions and other factors such as chest computed tomography (CT) findings was evaluated. RESULTS: The most common radiological finding in patients with lymphocyte-dominant BALF was GGO, with only one patient exhibiting consolidation. However, patients with eosinophil-dominant BALF were more likely to have consolidation; only three cases showed crazy paving and one showed GGO. In addition, patients with a GGO-dominant pattern on CT had an increased lymphocyte fraction of 41.0%; those with a consolidation-dominant pattern showed a relatively high eosinophil fraction of 5.2%; and those with a crazy paving pattern showed elevated eosinophil and neutrophil fractions of 19.1% and 9.9%, respectively. CONCLUSIONS: In this study, a remarkable difference in radiological findings was observed among different BALF patterns.

Effects of Sodium-Glucose Cotransporter 2 Inhibition on Glucose Metabolism, Liver Function, Ascites, and Hemodynamics in a Mouse Model of Nonalcoholic Steatohepatitis and Type 2 Diabetes.

Many blood glucose-lowering drugs cannot be used once patients with type 2 diabetes (T2D) and nonalcoholic fatty liver disease develop nonalcoholic steatohepatitis (NASH). Therefore, such patients often require insulin treatment. We aimed to determine the effect of sodium-glucose cotransporter 2 inhibitor (SGLT2i) dapagliflozin monotherapy on glucose metabolism in a mouse model of NASH/T2D, with a focus on its diuretic effects. To imitate ascites and to determine its severity by imaging, meglumine sodium amidotrizoate (MSA) was infused into the abdominal cavities of mice. The reduction in ascites induced by dapagliflozin was compared with that induced by furosemide using microcomputed tomography. The effects of each drug on hemodynamics were also compared. A dapagliflozin-related improvement in glucose tolerance was achieved in mice fed a high-fat diet (HFD) or an HFD + methionine-and-choline-deficient diet (MCDD). In dapagliflozin-treated NASH mice, hypoglycemia was not identified during 24-hour casual blood glucose monitoring. In the dapagliflozin and furosemide-treated groups, the time taken for the resolution of artificial ascites was significantly shorter than in the untreated group, and there were no significant differences between these groups. Furosemide significantly reduced the blood pressure and significantly increased the heart rate of the mice. Dapagliflozin caused a mild decrease in systolic, but not diastolic blood pressure, and the heart rate and circulating catecholamine and renin-aldosterone concentrations were unaffected. Dapagliflozin treatment improved glycemic control in the NASH mice versus untreated mice. Thus, dapagliflozin had a prompt diuretic effect but did not adversely affect the hemodynamics of mice with NASH and T2D. Therefore, it may be useful for the treatment of patients with both T2D and liver cirrhosis.

Preoperative assessment of parietal pleural invasion/adhesion of subpleural lung cancer: advantage of software-assisted analysis of 4-dimensional dynamic-ventilation computed tomography.

OBJECTIVE: To evaluate the accuracy of four-dimensional (4D) dynamic-ventilation computed tomography (CT) scanning coupled with our novel image analysis software to diagnose parietal pleural invasion/adhesion of peripheral (subpleural) lung cancer. METHODS: Eighteen patients with subpleural lung cancer underwent both 4D dynamic-ventilation CT during free breathing and conventional (static) chest CT during preoperative assessment. The absence of parietal pleural invasion/adhesion was surgically confirmed in 13 patients, while the presence of parietal pleural invasion/adhesion was confirmed in 5 patients. Two chest radiologists, who were blinded to patient status, cooperatively evaluated the presence of pleural invasion/adhesion using two different imaging modalities: (i) conventional high-resolution CT images, reconstructed in the axial, coronal, and sagittal directions, and (ii) 4D dynamic-ventilation CT images combined with a color map created by image analysis software to visualize movement differences between the lung surface and chest wall. Parameters of diagnostic accuracy were assessed, including a receiver operating characteristic analysis. RESULTS: Software-assisted 4D dynamic-ventilation CT images achieved perfect diagnostic accuracy for pleural invasion/adhesion (sensitivity, 100%; specificity, 100%; area under the curve [AUC], 1.000) compared to conventional chest CT (sensitivity, 60%; specificity, 77%; AUC, 0.846). CONCLUSION: Software-assisted 4D dynamic-ventilation CT can be considered as a novel imaging approach for accurate preoperative analysis of pleural invasion/adhesion of peripheral lung cancer. KEY POINTS: • 4D dynamic-ventilation CT can correctly assess parietal pleural invasion/adhesion of peripheral lung cancer. • A unique color map clearly demonstrates parietal pleural invasion/adhesion. • Our technique can be expanded to diagnose "benign" pleural adhesions for safer thoracoscopic surgery.

Strain measurement on four-dimensional dynamic-ventilation CT: quantitative analysis of abnormal respiratory deformation of the lung in COPD.

PURPOSE: Strain measurement is frequently used to assess myocardial motion in cardiac imaging. This study aimed to apply strain measurement to pulmonary motion observed by four-dimensional dynamic-ventilation computed tomography (CT) and to clarify motion abnormality in COPD. MATERIALS AND METHODS: Thirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during spontaneous breathing. CT data were continuously reconstructed every 0.5 seconds. In the series of images obtained by dynamic-ventilation CT, five expiratory frames were identified starting from the peak inspiratory frame (first expiratory frame) and ending with the fifth expiratory frame. Strain measurement of the scanned lung was performed using research software that was originally developed for cardiac strain measurement and modified for assessing deformation of the lung. The measured strain values were divided by the change in mean lung density to adjust for the degree of expiration. Spearman's rank correlation analysis was used to evaluate associations between the adjusted strain measurements and various spirometric values. RESULTS: The adjusted strain measurement was negatively correlated with FEV1/FVC (ρ=-0.52, P<0.01), maximum mid-expiratory flow (ρ=-0.59, P<0.001), and peak expiratory flow (ρ=-0.48, P<0.01), suggesting that abnormal deformation of lung motion is related to various patterns of expiratory airflow limitation. CONCLUSION: Abnormal deformation of lung motion exists in COPD patients and can be quantitatively assessed by strain measurement using dynamic-ventilation CT. This technique can be expanded to dynamic-ventilation CT in patients with various lung and airway diseases that cause abnormal pulmonary motion.

Quantitative CT density histogram values and standardized uptake values of FDG-PET/CT with respiratory gating can distinguish solid adenocarcinomas from squamous cell carcinomas of the lung.

PURPOSE: To assess the ability of parameters derived from computed tomography (CT) histograms and the maximum standardized uptake value (SUVmax) of 18F-fludeoxyglucose-positron emission tomography/CT (FDG-PET/CT) images to distinguish solid lung adenocarcinomas from squamous cell carcinomas and to determine if these parameters are correlated. METHODS: This study comprised 43 consecutive patients with solid lung cancer (<3 cm in diameter), who underwent both plain chest CT and FDG-PET/CT (adenocarcinoma, n = 25; squamous cell carcinoma, n = 18). Density histograms of targeted lung cancers were created from chest CT images, and kurtosis and skewness were calculated. On FDG-PET/CT, the SUVmax without/with respiratory gating (RG) were calculated for each lesion. The values for the 4 parameters determined for patients in each diagnostic group were compared by the Mann-Whitney test. The diagnostic characteristics of the parameters were assessed by receiver operating characteristic (ROC) curve analysis. Differences between these parameters were assessed by the chi-square test. SUVmax with RG, kurtosis, and skewness were combined for binary logistic regression analysis, and the differences between the combined parameters and SUVmax with RG were also assessed. Spearman rank correlation analysis was used to determine the correlations for kurtosis or for skewness with SUVmax without/with RG. RESULTS: The differences in kurtosis and SUVmax without/with RG between the diagnostic groups were significant (kurtosis, P < 0.004; SUVmax without/with RG both P < 0.0001). ROC curve analysis indicated that each parameter (kurtosis value, skewness value, SUVmax, without/with RG) provided low-high ability to differentiate between 2 groups (area under the curve [AUC]: 0.760, 0.593, 0.900, 0.931, respectively). The ROC of the combined parameters provided the highest ability (AUC: 0.949). Both kurtosis and skewness were significantly correlated with SUVmax without/with RG. Kurtosis and SUVmax with RG were most strongly correlated (ρ = 0.618). CONCLUSION: Quantitative CT histogram values and SUV assessment can differentiate solid lung adenocarcinomas from squamous cell carcinomas. Kurtosis and SUVmax values were strongly correlated. The addition of RG and further combination of the parameters improved the results.

MRI findings and demographics of elastofibroma dorsi: assessment of diffusion-weighted imaging and contrast enhancement patterns.

Background Elastofibroma dorsi is a rare pseudotumoral lesion. Thus, there is no report of magnetic resonance imaging (MRI) findings that investigates multiple patients particularly with respect to diffusion-weighted imaging (DWI) findings and contrast enhancement patterns. Purpose To describe the imaging findings of elastofibroma on MRI, particularly DWI findings and contrast enhancement patterns, and to further investigate patient demographics. Material and Methods Forty-four patients with elastofibroma that underwent MRI were enrolled in this retrospective study. All images were evaluated by two radiologists to visually assess the signal intensity for each sequence. Enhanced elastofibromas were classified into four categories to assess the enhancement pattern. Differences in gender and laterality were also assessed statistically. Results An equal number of men and women were included (n = 22 each). There was no significant difference in laterality ( P = 0.783). All lesions (73 lesions) had low signal intensity on both T1-weighted (T1W) and T2-weighted (T2W) images: heterogeneous in 56, homogeneous in 17. None of the 41 lesions with DWI had true abnormal diffusion restriction. The average ADC value was 1.36 × 10-3 ± 0.29 mm2/s. All 31 lesions that had contrast-enhanced MRI were classified according to enhancement pattern: homogeneous (three lesions, 9.7%); heterogeneous (15 lesions, 48.4%); streak-like (three lesions, 9.7%); and rim-like (ten lesions, 32.2%). Conclusion There were no statistically significant differences in gender or laterality. Elastofibroma showed homogeneous to heterogeneous low signal intensity on T1W and T2W images. No lesion showed abnormal diffusion restriction, and all lesions demonstrated enhancement on MRI.

Hyperinflated lungs compress the heart during expiration in COPD patients: a new finding on dynamic-ventilation computed tomography.

PURPOSE: The aims of this study were to evaluate dynamic changes in heart size during the respiratory cycle using four-dimensional computed tomography (CT) and to understand the relationship of these changes to airflow limitation in smokers. MATERIALS AND METHODS: A total of 31 smokers, including 13 with COPD, underwent four-dimensional dynamic-ventilation CT during regular breathing. CT data were continuously reconstructed every 0.5 s, including maximum cross-sectional area (CSA) of the heart and mean lung density (MLD). Concordance between the cardiac CSA and MLD time curves was expressed by cross-correlation coefficients. The CT-based cardiothoracic ratio at inspiration and expiration was also calculated. Comparisons of the CT indices between COPD patients and non-COPD smokers were made using the Mann-Whitney test. Spearman rank correlation analysis was used to evaluate associations between CT indices and the forced expiratory volume in 1 s (FEV1.0) relative to the forced vital capacity (FVC). RESULTS: Cardiac CSA at both inspiration and expiration was significantly smaller in COPD patients than in non-COPD smokers (P<0.05). The cross-correlation coefficient between cardiac CSA and MLD during expiration significantly correlated with FEV1.0/FVC (ρ=0.63, P<0.001), suggesting that heart size decreases during expiration in COPD patients. The change in the cardiothoracic ratio between inspiration and expiration frames was significantly smaller in COPD patients than in non-COPD smokers (P<0.01). CONCLUSION: Patients with COPD have smaller heart size on dynamic-ventilation CT than non-COPD smokers and have abnormal cardiac compression during expiration.

Asynchrony in respiratory movements between the pulmonary lobes in patients with COPD: continuous measurement of lung density by 4-dimensional dynamic-ventilation CT.

PURPOSE: Four-dimensional dynamic-ventilation CT imaging demonstrates continuous movement of the lung. The aim of this study was to assess the correlation between interlobar synchrony in lung density and spirometric values in COPD patients and smokers, by measuring the continuous changes in lung density during respiration on the dynamic-ventilation CT. MATERIALS AND METHODS: Thirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during free breathing. CT data were continuously reconstructed every 0.5 sec. Mean lung density (MLD) of the five lobes (right upper [RU], right middle [RM], right lower [RL], left upper [LU], and left lower [LL]) was continuously measured by commercially available software using a fixed volume of volume of interest which was placed and tracked on a single designated point in each lobe. Concordance between the MLD time curves of six pairs of lung lobes (RU-RL, RU-RM, RM-RL, LU-LL, RU-LU, and RL-LL lobes) was expressed by cross-correlation coefficients. The relationship between these cross-correlation coefficients and the forced expiratory volume in one second/forced vital capacity (FEV1.0/FVC) values was assessed by Spearman rank correlation analysis. RESULTS: In all six pairs of the pulmonary lobes, the cross-correlation coefficients of the two MLD curves were significantly positively correlated with FEV1.0/FVC (ρ =0.60-0.73, P<0.001). The mean value of the six coefficients strongly correlated with FEV1.0/FVC (ρ =0.80, P<0.0001). CONCLUSION: The synchrony of respiratory movements between the pulmonary lobes is limited or lost in patients with more severe airflow limitation.

CT and MR Imaging of Gynecologic Emergencies.

Gynecologic emergencies include various diseases that result from adnexal and uterine disorders. Adnexal disorders may be classified into the following three categories: (a) disorders that cause hemorrhage (hemorrhagic ovarian cysts and ectopic pregnancies); (b) disorders related to adnexal tumors (adnexal torsion and rupture of ovarian tumors); and (c) disorders related to pelvic inflammatory disease, such as tubo-ovarian abscesses. Unusual adnexal torsion, such as massive ovarian edema, isolated fallopian tube torsion, and paraovarian cyst torsion, has also been described. Uterine disorders in gynecologic emergencies may be classified into two categories: (a) acute fibroid complications, including red degeneration of a uterine leiomyoma, torsion of subserosal myomas, and torsion of the uterus; and (b) causes of acute uterine bleeding, including retained products of conception and uterine arteriovenous malformations. Some gynecologic diseases are self-limited, while others cause infertility or life-threatening infection or bleeding if left untreated. Therefore, prompt and accurate diagnosis is important for appropriate life-saving treatment and for the preservation of fertility. The imaging findings are important when evaluating acute gynecologic diseases because the symptoms and physical examination findings are often nonspecific and limited. Ultrasonography is the first-line imaging modality; however, when a definitive diagnosis cannot be established, computed tomography (CT) and magnetic resonance (MR) imaging may narrow the differential diagnosis. Appropriate management requires radiologists to be familiar with the CT and MR imaging features of gynecologic emergencies. With respect to rare conditions, radiologists should take into account the representative findings presented in this article to increase diagnostic accuracy. ©RSNA, 2017.

Low-Grade Endometrial Stromal Sarcoma with Intravenous and Intracardiac Extension: A Multidisciplinary Approach.

Background. A rare case of low-grade endometrial stromal sarcoma (LG-ESS) extending to inferior vena cava (IVC) and cardiac chambers. Case Report. A 40-year-old woman had IVC tumor, which was incidentally detected by abdominal ultrasonography during a routine medical checkup. CT scan revealed a tumor in IVC, right iliac and ovarian veins, which was derived from the uterus and extended into the right atrium and ventricle. The operation was performed, the heart and IVC were exposed, and cardiopulmonary bypass was initiated. A right atriotomy was performed, and the intracardiac mass was removed. Then the tumor in IVC and the right internal iliac vein were removed after longitudinal venotomies in the suprarenal and infrarenal vena cava, the right common iliac vein. Next the pelvis was explored. Tumors were found originating from the posterior wall of the uterus and continuing into both the right uterine and ovarian vein. The patient underwent total hysterectomy with bilateral salpingooophorectomy. Complete tumor resection was achieved. Histopathological analysis confirmed a diagnosis of LG-ESS. She showed no evidence of disease for 2 years and 3 months. Conclusions. Our case highlights the importance of a multidisciplinary approach in treating this rare cardiovascular pathological condition through preoperative assessment to final operation.

Continuous quantitative measurement of the proximal airway dimensions and lung density on four-dimensional dynamic-ventilation CT in smokers.

PURPOSE: Four-dimensional dynamic-ventilation computed tomography (CT) imaging demonstrates continuous movement of the airways and lungs, which cannot be depicted with conventional CT. We aimed to investigate continuous changes in lung density and airway dimensions and to assess the correlation with spirometric values in smokers. MATERIALS AND METHODS: This retrospective study was approved by the Institutional Review Board, and informed consent was waived. Twenty-one smokers including six patients with COPD underwent four-dimensional dynamic-ventilation CT during free breathing (160 mm in length). The mean lung density (MLD) of the scanned lung and luminal areas (Ai) of fixed points in the trachea and the right proximal bronchi (main bronchus, upper bronchus, bronchus intermedius, and lower bronchus) were continuously measured. Concordance between the time curve of the MLD and that of the airway Ai values was expressed by cross-correlation coefficients. The associations between these quantitative measurements and the forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) values were assessed by Spearman's rank correlation analysis. RESULTS: On the time curve for the MLD, the Δ-MLD1.05 values between the peak inspiratory frame to the later third frame (1.05 seconds later) were strongly correlated with the FEV1/FVC (ρ=0.76, P<0.0001). The cross-correlation coefficients between the airway Ai and MLD values were significantly correlated with the FEV1/FVC (ρ=-0.56 to -0.66, P<0.01), except for the right upper bronchus. This suggested that the synchrony between the airway and lung movement was lost in patients with severe airflow limitation. CONCLUSION: Respiratory changes in the MLD and synchrony between the airway Ai and the MLD measured with dynamic-ventilation CT were correlated with patient's spirometric values.

Can Peripheral Bronchopleural Fistula Demonstrated on Computed Tomography be Treated Conservatively? A Retrospective Analysis.

PURPOSE: Peripheral bronchopleural fistulas (BPF) are communications between a peripheral bronchus or the lung parenchyma and the pleural space. Although reported cases with peripheral BPF might have typical symptoms, we postulate that there may be BPF patients without typical symptoms who are diagnosed on computed tomography (CT) for the first time. MATERIALS AND METHODS: We searched retrospectively for how frequently BPF is found on CT in cases with known or suspected empyema or hydropneumothorax. Also, we examined the clinical charts to ascertain if a diagnosis of BPF was suspected in the CT reports or clinically, and to determine the outcome of each case. RESULTS: Thirteen thoracic cavities of 12 patients were included in this study. Of these, BPF was suspected clinically in only 1. Mention in the CT report about the presence of BPF was found in 2 cases. An apparent finding of BPF on CT was found in 7 of 13 (53%) thoracic cavities of 6 cases. The outcomes were that 1 patient died 1 month later due to multiple organ failure, and 1 patient was discharged subsequently after CT. In the other 10 cases, there was no exacerbation of the symptom regardless of definite evidence of BPF on CT. CONCLUSIONS: In conclusion, when there is hydropneumothorax on CT, it is important for radiologists to diligently search for findings of peripheral BPF and to document it. However, a reference about the need for a surgical approach for BPF may not be required.

Bilateral duplication of the abducens nerves: an incidental finding on magnetic resonance imaging.

Although anomaly of the abducens nerve, including duplication, has been reported in anatomical papers, no radiological report exists regarding a duplicated abducens nerve observed on magnetic resonance (MR) imaging. We encountered a case of bilateral duplication of the abducens nerves, which was found incidentally on MR scans from an 11-year-old boy. He did not have any symptoms of eye movement related to abducens nerve abnormality; thus, the duplication was considered to be a normal variant in this patient. Radiologists should be aware that duplication of the abducens nerve may occur and can be diagnosed on MR, particularly when diagnosing symptomatic patients or as a preoperative assessment for microsurgery of the nerve.

Automated continuous quantitative measurement of proximal airways on dynamic ventilation CT: initial experience using an ex vivo porcine lung phantom.

BACKGROUND: The purpose of this study was to evaluate the feasibility of continuous quantitative measurement of the proximal airways, using dynamic ventilation computed tomography (CT) and our research software. METHODS: A porcine lung that was removed during meat processing was ventilated inside a chest phantom by a negative pressure cylinder (eight times per minute). This chest phantom with imitated respiratory movement was scanned by a 320-row area-detector CT scanner for approximately 9 seconds as dynamic ventilatory scanning. Obtained volume data were reconstructed every 0.35 seconds (total 8.4 seconds with 24 frames) as three-dimensional images and stored in our research software. The software automatically traced a designated airway point in all frames and measured the cross-sectional luminal area and wall area percent (WA%). The cross-sectional luminal area and WA% of the trachea and right main bronchus (RMB) were measured for this study. Two radiologists evaluated the traceability of all measurable airway points of the trachea and RMB using a three-point scale. RESULTS: It was judged that the software satisfactorily traced airway points throughout the dynamic ventilation CT (mean score, 2.64 at the trachea and 2.84 at the RMB). From the maximum inspiratory frame to the maximum expiratory frame, the cross-sectional luminal area of the trachea decreased 17.7% and that of the RMB 29.0%, whereas the WA% of the trachea increased 6.6% and that of the RMB 11.1%. CONCLUSION: It is feasible to measure airway dimensions automatically at designated points on dynamic ventilation CT using research software. This technique can be applied to various airway and obstructive diseases.