Results in Academic radiology: 9,770
(searched for: container_group_id:1306)
Academic radiology, Volume 29; https://doi.org/10.1016/j.acra.2017.08.007
The purpose of this study is to improve accuracy of near-term breast cancer risk prediction by applying a new mammographic image conversion method combined with a two-stage artificial neural network (ANN)-based classification scheme.The dataset included 168 negative mammography screening cases. In developing and testing our new risk model, we first converted the original grayscale value (GV)-based mammographic images into optical density (OD)-based images. For each case, our computer-aided scheme then computed two types of image features representing bilateral asymmetry and the maximum of the image features computed from GV and OD images, respectively. A two-stage classification scheme consisting of three ANNs was developed. The first stage included two ANNs trained using features computed separately from GV and OD images of 138 cases. The second stage included another ANN to fuse the prediction scores produced by two ANNs in the first stage. The risk prediction performance was tested using the rest 30 cases.With the two-stage classification scheme, the computed area under the receiver operating characteristic curve (AUC) was 0.816 ± 0.071, which was significantly higher than the AUC values of 0.669 ± 0.099 and 0.646 ± 0.099 achieved using two ANNs trained using GV features and OD features, respectively (P < .05).This study demonstrated that applying an OD image conversion method can acquire new complimentary information to those acquired from the original images. As a result, fusion image features computed from these two types of images yielded significantly higher performance in near-term breast cancer risk prediction.
Academic radiology, Volume 25; https://doi.org/10.1016/j.acra.2017.08.015
Academic radiology, Volume 24, pp 1329-1331; https://doi.org/10.1016/j.acra.2017.08.001
Academic radiology, Volume 24, pp 1535-1543; https://doi.org/10.1016/j.acra.2017.07.007
Changes in the composition of body tissues are major aging phenotypes, but they have been difficult to study in depth. Here we describe age-related change in abdominal tissues observable in computed tomography (CT) scans. We used pattern recognition and machine learning to detect and quantify these changes in a model-agnostic fashion. CT scans of abdominal L4 sections were obtained from Baltimore Longitudinal Study of Aging (BLSA) participants. Age-related change in the constituent tissues were determined by training machine classifiers to differentiate age groups within male and female strata (“Younger” at 50–70 years old vs “Older” at 80–99 years old). The accuracy achieved by the classifiers in differentiating the age cohorts was used as a surrogate measure of the aging signal in the different tissues. The highest accuracy for discriminating age differences was 0.76 and 0.72 for males and females, respectively. The classification accuracy was 0.79 and 0.71 for adipose tissue, 0.70 and 0.68 for soft tissue, and 0.65 and 0.64 for bone. Using image data from a large sample of well-characterized pool of participants dispersed over a wide age range, we explored age-related differences in gross morphology and texture of abdominal tissues. This technology is advantageous for tracking effects of biological aging and predicting adverse outcomes when compared to the traditional use of specific molecular biomarkers. Application of pattern recognition and machine learning as a tool for analyzing medical images may provide much needed insight into tissue changes occurring with aging and, further, connect these changes with their metabolic and functional consequences.
Academic radiology, Volume 25, pp 18-25; https://doi.org/10.1016/j.acra.2017.05.019
Barriers to MRR include funding and establishing a central database and a picture archiving and communication system. Upon embarking on an MRR project, forming a motivated team who meets and speaks regularly is essential.
Academic radiology, Volume 24, pp 1517-1525; https://doi.org/10.1016/j.acra.2017.06.018
The aim of the study was to evaluate the overall survival (OS) rate, progression survival rate, and local control rate over 10 years of medically inoperable patients with lung cancer undergoing computed tomography (CT)-guided radiofrequency ablation (RFA). Between September 2004 to March 2016, 668 neoplasms were treated in 476 medically inoperable patients (294 men, 60 women; median age 74 years; range 29–84) who underwent CT-guided RFA. All patients had clinical or pathologic evidence of the neoplastic lesion: 22.1% patients with primary non–small cell lung cancer (NSCLC), 22.3% patients with recurrent NSCLC, 45.2% with metastases, and 10.3% with small cell lung cancer. The mean size of the lesions was 3.8 cm (range of 1–16 cm). Twenty-one lesions were re-treated from one to as many as four times. The procedure was technically successful in all cases. No procedure-related deaths occurred in the RFA procedures. Major complications consisted in 104 (21.8%) cases of low-grade fever, 46 (9.6%) of the pneumothorax. The mean follow-up was 32 months. The probabilities of 1-, 2-, 3-, 5-, and 10-year OS rate were 98.1%, 86.6%, 68.9% 34.5%, and 9.5% for primary NSCLC; 59.7%, 18.5%, 8%, 3.4%, and 1.5% for metastases; 93.3%, 59.1%, 49.6%, 19.7%, and 0% for recurrence; and 89.4%, 67.5%, 39.1%, 16.5%, and 0% for small cell lung cancer. In primary NSCLC, progression-free survival (PFS) and OS were significantly related to tumor size, but there was no significant difference in recurrent NSCLC, metastasis, and peripheral SCLC. The median OS of metastases of NSCLC was significantly related to nodal or distant metastases. The most common pattern of recurrence was local; any type of recurrence at 1-year follow-up imaging was seen in 7.1% of primary NSCLC diameter less than 3 cm. Our experience indicates that CT-guided RFA done by the thoracic surgeons is feasible and safe in high-risk patients. Maximum tumor diameter less than 3 cm and lack of extrapulmonary metastasis are all positive prognostic factors of survival after RFA. RFA offers good local control of recurrent NSCLC, lung metastases, and SCLC, also in the long-term period. RFA should continue to offer an alternative option in medically inoperable patients.
Academic Radiology, Volume 20, pp 66-72; https://doi.org/10.1016/j.acra.2012.08.002
Both preoperative computed tomography (CT) staging and postoperative surgical Masaoka clinical staging are of great clinical importance for diagnosing thymomas. Our study aimed to investigate the relationships between these two staging systems. This was a retrospective review of 129 patients who had undergone thymoma surgery. Helical CT and 16-slice CT were performed preoperatively. Surgical findings were evaluated according to the Masaoka clinical staging system. A significant association was shown between Masaoka clinical staging and CT staging, especially of features including tumor size (P = .004), tumor shape (P < .001), tumor density (P < .001), capsule completeness (P < .001), and involvement of surrounding tissues (P < .001). Based on the CT findings, there were 35.09% of Masaoka stage I patients who had a tumor size <5 cm as compared to 14.81% of stage IV patients. Only 8.77% of Masaoka stage I patients had a tumor size ≥10 cm as compared to 40.74% of stage IV patients. In stages III and IV, most tumors were irregularly shaped with an uneven density and incomplete capsule. Invasive tumors were more frequently found in stages III (81.48%) and IV (88.89%) than in stages I (0%) and II (38.89%). The incidence of myasthenia gravis was comparable in different stages. Consistency between CT and Masaoka clinical stages was higher in stage I (37.98%) than other stages (approximately 10%). This study documented a close relationship between preoperative CT thymoma staging and postoperative Masaoka clinical staging. Thus, preoperative CT findings can be beneficial for determining the proper management and prognosis of thymoma patients.
Academic radiology, Volume 20, pp 99-107; https://doi.org/10.1016/j.acra.2012.07.009
The publisher has not yet granted permission to display this abstract.
Academic radiology, Volume 25, pp 26-39; https://doi.org/10.1016/j.acra.2017.07.013
Funding for research has become increasingly difficult to obtain in an environment of decreasing clinical revenue, increasing research costs, and growing competition for federal and nonfederal funding sources. This paper identifies critical requirements to build and sustain a successful radiology research program (eg, key personnel and leadership, research training and mentorship, infrastructure, institutional and departmental funding or support), reviews the current state of available funding for radiology (including federal, nonfederal, philanthropy, crowdfunding, and industry), and describes promising opportunities for future funding (eg, health services, comparative effectiveness, and patient-centered outcomes research). The funding climate, especially at the federal level, changes periodically, so it is important to have radiology-specific organizations such as the American College of Radiology and the Academy of Radiology Research serving as our key advocates. Key to obtaining any funding, no matter what the source, is a well-formulated grant proposal, so a review of opportunities specifically available to radiologists to develop and hone their grant-writing skills is provided. Effective and sustained funding for radiology research has the potential to cultivate young researchers, bolster quality research, and enhance health care. Those interested in pursuing research need to be aware of the ever-changing funding landscape, research priority areas, and the resources available to them to succeed. To succeed, radiology researchers need to think about diversification and flexibility in their interests, developing multidisciplinary and multi-institutional projects, and engaging a broader base of stakeholders that includes patients.
Academic radiology, Volume 25, pp 129-135; https://doi.org/10.1016/j.acra.2017.07.009
Rationale and Objectives We investigated the feasibility of detecting left ventricular (LV) cardiac magnetic resonance (CMR) strain abnormalities using feature-tracking in patients with pulmonary hypertension (PH). Materials and Methods CMR was performed in 16 patients with all groups of PH and in 13 controls. Global and regional peak circumferential strains (%) (which have been shown to be robust by CMR), peak diastolic strain rate (%/s), and dyssynchrony index (ms) were quantified with feature-tracking software. Ventricular function and volumes were calculated from CMR, and right heart pressures were measured with catheterization. Results Left ventricular ejection fraction (LVEF) was similar in patients (60.2% ± 11.0%) and controls (61.9% ± 4.5%), P = .150. Global LV peak circumferential strain was significantly different in patients compared to controls, −16.7 ± 2.8% vs −19.9 ± 1.8%, respectively (P = .001). The greatest difference in strain was seen in the LV septum, −11.6 ± 4.3% in patients vs −16.7 ± 4.0% in controls (P < .001). There was a significant association between septal strain and right ventricular end-diastolic volume index (P = .047) in patients with PH; however, there were no associations with pulmonary artery pressures or right ventricular ejection fraction. Conclusions Feature-tracking CMR can detect LV strain abnormalities in patients with PH and preserved or mildly depressed LVEF, with greatest abnormality in the septum. The association between septal strain and right ventricular end-diastolic volume index suggests that ventricular interdependence may be a mechanism of LV dysfunction in PH. Feature-tracking CMR may be useful for identification of LV dysfunction before LVEF significantly declines in patients with PH. The feasibility of detecting LV strain abnormalities in patients with PH shown by this study paves the way for a variety of future investigations into the applications of LV strain in this patient population.
Academic radiology, Volume 25, pp 3-8; https://doi.org/10.1016/j.acra.2017.03.027
Radiology continues to benefit from constant innovation and technological advances. However, for promising new imaging technologies to reach widespread clinical practice, several milestones must be met. These include regulatory approval, early clinical evaluation, payer reimbursement, and broader marketplace adoption. Successful implementation of new imaging tests into clinical practice requires active stakeholder engagement and a focus on demonstrating clinical value during each phase of translation.
Academic radiology, Volume 24, pp 1473-1481; https://doi.org/10.1016/j.acra.2017.07.003
Rationale and Objectives The study aimed to determine if intrathoracic fat volumes are associated with the presence and severity of systemic sclerosis (SSc), defined by the presence of pulmonary arterial hypertension (PAH). Materials and Methods A total of 265 patients were included in the study, 202 of whom had SSc (134 had SSc with no PAH and 68 had SSc-associated PAH) and who underwent high-resolution computed tomography, and 63 controls who underwent coronary computed tomography angiography with calcium scoring. Intrathoracic and epicardial (EFV) fat volumes were quantified by manual tracing of the mediastinum and the pericardium, the difference of which represents the extrapericardial fat volume. Associations between these three fat volumes and the presence and severity of SSc, adjusted for cardiovascular risk factors and interstitial lung disease, were evaluated by logistic regression analysis. Results Of the 202 patients with SSc, the mean age was 55 years (ranged from 20 to 86), and 79% (159 of 202) were women. Adjusted EFV (odds ratio [OR]: 1.065; 95% confidence interval [CI]: 1.046–1.084, P = < 0.0001), extrapericardial fat volume (OR: 1.028, 95% CI: 1.017–1.038, P = < 0.0001), and intrathoracic fat volume (OR: 1.033, 95% CI: 1.023–1.043, P = 0.001) were associated with the presence of SSc. Only EFV was associated with SSc severity (adjusted OR: 1.010, 95% CI: 1.003–1.018, P = 0.007). Conclusion Increased epicardial fat volume is associated with the presence and severity of SSc, independent of cardiovascular risk factors and interstitial lung disease.
Academic radiology, Volume 24, pp 1604-1611; https://doi.org/10.1016/j.acra.2017.07.008
This study aimed to differentiate pathologically defined lepidic predominant lesions (LPL) from more invasive adenocarcinomas (INV) using three-dimensional (3D) volumetric density and first-order texture histogram analysis of surgically excised stage 1 lung adenocarcinomas. This retrospective study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Sixty-four cases of pathologically proven stage 1 lung adenocarcinoma surgically resected between September 2006 and October 2015, including LPL (n = 43) and INV (n = 21), were evaluated using high-resolution computed tomography. Quantitative measurements included nodule volume, percent solid volume (% solid), and first-order texture histogram analysis including skewness, kurtosis, entropy, and mean nodule attenuation within each histogram quartile. Binomial logistic regression models were used to identify the best set of parameters distinguishing LPL from INV. Univariate analysis of 3D volumetric density and histogram features was statistically significant between LPL and INV groups (P < .05). Accuracy of a binomial logistic model to discriminate LPL from INV based on size and % solid was 85.9%. With optimized probability cutoff, the model achieves 81% sensitivity, 76.7% specificity, and area under the receiver operating characteristic curve of 0.897 (95% confidence interval, 0.821–0.973). An additional model based on size and mean nodule attenuation of the third quartile (Hu_Q3) of the histogram achieved similar accuracy of 81.3% and area under the receiver operating characteristic curve of 0.877 (95% confidence interval, 0.790–0.964). Both 3D volumetric density and first-order texture analysis of stage 1 lung adenocarcinoma allow differentiation of LPL from more invasive adenocarcinoma with overall accuracy of 85.9%–81.3%, based on multivariate analyses of either size and % solid or size and Hu_Q3, respectively.
Academic radiology, Volume 24, pp 1621-1623; https://doi.org/10.1016/j.acra.2017.07.006
Academic radiology, Volume 25, pp 9-17; https://doi.org/10.1016/j.acra.2017.05.020
Radiology as a discipline thrives on the dynamic interplay between technological and clinical advances. Progress in almost all facets of the imaging sciences is highly dependent on complex tools sourced from physics, engineering, biology, and the clinical sciences to obtain, process, and view imaging studies. The application of these tools, however, requires broad and deep medical knowledge about disease pathophysiology and its relationship with medical imaging. This relationship between clinical medicine and imaging technology, nurtured and fostered over the past 75 years, has cultivated extraordinarily rich collaborative opportunities between basic scientists, engineers, and physicians. In this review, we attempt to provide a framework to identify both currently successful collaborative ventures and future opportunities for scientific partnership. This invited review is a product of a special working group within the Association of University Radiologists-Radiology Research Alliance.
Academic radiology, Volume 25, pp 118-128; https://doi.org/10.1016/j.acra.2017.07.010
Rationale and Objectives To describe the rationale, design, and technical background of coronary artery calcium (CAC) imaging in the large-scale population-based cardiovascular disease screening trial (Risk Or Benefit IN Screening for CArdiovascular Diseases [ROBINSCA]). Materials and Methods First, literature search was performed to review the logistics, setup, and settings of previously performed CAC imaging studies, and current clinical CAC imaging protocols of participating centers in the ROBINSCA trial were evaluated. A second literature search was performed to evaluate the impact of computed tomography parameter settings on CAC score. Results Based on literature reviews and experts opinion an imaging protocol accompanied by data management protocol was created for ROBINSCA. The imaging protocol should consist of a fixed tube voltage, individually tailored tube current setting, mid-diastolic electrocardiography-triggering, fixed field-of-view, fixed reconstruction kernel, fixed slice thickness, overlapping reconstruction and without iterative reconstruction. The analysis of scans is performed with one type and version of CAC scoring software, by two dedicated and experienced researchers. The data management protocol describes the organization of data handling between the coordinating center, participating centers, and core analysis center. Conclusion In this paper we describe the rationale and technical considerations to be taken in developing CAC imaging protocol, and we present a detailed protocol that can be implemented for CAC screening purposes.
Academic Radiology, Volume 24, pp 1582-1587; https://doi.org/10.1016/j.acra.2017.06.013
The publisher has not yet granted permission to display this abstract.
Academic radiology, Volume 25, pp 95-101; https://doi.org/10.1016/j.acra.2017.07.012
To evaluate the performance of T2 star-weighted angiography (SWAN) to concomitantly assess the prostate contour while detecting fiducials before magnetic resonance (MR)-based intensity-modulated radiation therapy (IMRT) in prostate carcinoma.Forty patients (mean age: 73.1 ± 7.5 years; average Gleason score: 7 ± 1; average prostate-specific antigen: 14.7 ± 11.6 ng/mL) underwent MR and computed tomography imaging before fiducial-based IMRT. MR protocol included SWAN, T2-weighted (T2w) and diffusion-weighted imaging in a first group (n = 20) and SWAN, T2w and T2-star weighted imaging in a second group (n = 20). In group 1, the depiction of fiducials, image sharpness and visibility of prostate boundaries were independently evaluated by 2 readers on SWAN, T2w or diffusion-weighted images. In group 2, a similar evaluation was performed by 2 other readers on SWAN and T2-star images only. Depiction of fiducials was compared to computed tomography findings.The median scores of visibility of prostate boundaries, image sharpness and depiction of fiducials by SWAN were above average to excellent for all readers. In group 1, readers correctly located 56 of 57 (98.2%) and 47 of 57 (82.5%) fiducials, respectively; and 50 of 51 (98%), and 48 of 51 (88.2%) fiducials in group 2, respectively.By allowing adequate visualization of the prostate boundaries and high depiction of fiducial markers concomitantly, SWAN might be used for treatment planning of IMRT. The use of this sequence might simplify the registration process and limit any errors associated with image fusion.
Academic radiology, Volume 24, pp 1185-1186; https://doi.org/10.1016/j.acra.2017.07.004
Academic radiology, Volume 25, pp 88-94; https://doi.org/10.1016/j.acra.2017.07.011
Several minimally invasive thermal techniques have been developed for the treatment of benign thyroid nodules. A new technique for this indication is high-intensity focused ultrasound (HIFU). The aim of this study was to assess effectiveness in varying preablative nodule volumes and whether outcome patterns that were reported during studies with other thermal ablative procedures for thyroid nodule ablation would also apply to HIFU.Over the last 2 years, 19 nodules in 15 patients (12 women) whose average age was 58.7 years (36-80) were treated with HIFU in an ambulatory setting. Patients with more than one nodule were treated in multiple sessions on the same day. The mean nodule volume was 2.56 mL (range 0.13-7.67 mL). The therapeutic ultrasound probe (Echopulse THC900888-H) used in this series functions with a frequency of 3 MHz, reaching temperatures of approximately 80°C-90°C and delivering an energy ranging from 87.6 to 320.3 J per sonication. To assess the effectiveness of thermal ablation, nodular volume was measured at baseline and at 3-month follow-up. The end point of the study was the volume reduction assessment after 3 months' follow-up. Therapeutic success was defined as volume reduction of more than 50% compared to baseline. This study was retrospectively analyzed using the Wilcoxon signed rank test and Kendall tau.The median percentage volume reduction of all 19 nodules after 3 months was 58%. An inverse correlation between preablative nodular volume and percentage volume shrinking was found (tau = -0.46, P < .05). Therapeutic success was achieved in 10 out of 19 patients (53%).HIFU of benign thyroid nodules can be carried out as an alternative therapy for nodules ≤3 mL if patients are refusing surgery or radioiodine therapy.
Academic radiology, Volume 20, pp 128-130; https://doi.org/10.1016/j.acra.2012.05.012
Academic radiology, Volume 24, pp 1468-1469; https://doi.org/10.1016/j.acra.2017.07.005
Academic radiology, Volume 24, pp 1616-1620; https://doi.org/10.1016/j.acra.2017.06.007
For imaging pediatric appendicitis, ultrasonography (US) is preferred because of its lack of ionizing radiation, but is limited by operator dependence. This study investigates the US diagnostic performance during night shifts covered by radiology trainees compared to day shifts covered by attending radiologists. Appy-Scores (1 = completely visualized normal appendix; 2 = partially visualized normal appendix; 3 = nonvisualized appendix with no inflammatory changes in the expected region of the appendix; 4 = equivocal; 5a = nonperforated appendicitis; 5b = perforated appendicitis) from 2935 US examinations (2161:774, day-to-night) from July 2013 to 2014 were correlated with the intraoperative diagnoses and the clinical follow-up. The diagnostic performance of trainees and attendings was compared with Fisher exact test. Interobserver agreement was measured by Cohen kappa coefficient. Appendicitis prevalence was 25.3% (day) and 22.5% (night). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive vale were 94.0%, 93.7%, 93.8%, 97.9%, and 83.4% during the day and 92.0%, 91.2%, 91.3%, 97.5%, and 75.2% at night. Specificity (P = .048) and positive predictive value (P = .011) differed, with more false positives at night (7%) than during the day (4.7%). Trainee and attending agreement was high (k = 0.995), with Appy-Scores of 1, 4, and 5a most frequently discordant. US has a high diagnostic performance and interobserver agreement for pediatric appendicitis when interpreted by radiology trainees during night shifts or attending radiologists during day shifts. However, lower specificity and positive predictive value at night warrants a thorough trainee education to avoid false-positive examinations.
Academic radiology, Volume 20, pp 41-51; https://doi.org/10.1016/j.acra.2012.08.005
Rationale and Objectives Radiolabeled tyrosine analogues that have been successfully used in tumor imaging accumulate in tumor cells via an upregulated L-type amino acid transporter system. The anticancer drug melphalan is an L-type amino acid transporter substrate. Therefore, radiolabeled tyrosine analogues may have great potential in evaluating treatment responses to melphalan. In this study, a 99mTc-labeled tyrosine analogue, 99mTc tyrosine using N,N′-ethylene-di-L-cysteine (EC) as a chelator, was developed and its potential for noninvasively assessing tumors' early response to melphalan determined. Materials and Methods EC-tyrosine was synthesized in a three-step procedure and labeled with 99mTc. To assess cellular uptake kinetics, the percentage uptake of 99mTc-EC-tyrosine in the rat breast cancer cell line 13762 was measured. Planar imaging was performed in rats with 13762 cell-derived tumors. To determine the transport mechanisms of 99mTc-EC-tyrosine, a competitive inhibition study using L-tyrosine as an inhibitor was performed in vitro and in vivo. To assess tumors' response to melphalan, tumor-bearing rats were treated with different doses of melphalan, and planar imaging was performed 0 and 3 days after treatment. Immunohistochemical analyses were conducted to determine expressions of L-type amino acid transporter 1 and cellular proliferation marker Ki-67. Results L-tyrosine significantly inhibited 99mTc-EC-tyrosine uptake in vitro and in vivo. Tumor volume decreased in a dose-dependent manner with melphalan, and tumor/muscle ratios of 99mTc-EC-tyrosine were significantly reduced in treated groups. Immunohistochemical data indicated that about 70% of tumor cells in the melphalan-treated groups underwent apoptosis, and the changes in tumor/muscle ratios reflected the decreased percentage of viable cells in treated tumors. Conclusions These findings suggest that 99mTc-EC-tyrosine has great potential for monitoring tumor response to melphalan in breast tumor–bearing rats.
Academic radiology, Volume 20, pp 16-24; https://doi.org/10.1016/j.acra.2012.08.001
Rationale and Objectives The aim of this study was to establish reference curves and formulas for aortic cross-sectional area in patients from infancy to young adulthood. Materials and Methods Patients (aged 2 days to 18.1 years) who underwent electrocardiographically gated cardiac computed tomography between May 2004 and December 2011 were retrospectively examined. These patients were further divided into a group of normal controls (without aortic disease) and a group with coarctation of aorta. In the group of normal controls, the cross-sectional area of the aorta was measured at six locations: the sinotubular junction, distal ascending aorta, proximal arch, distal arch, aortic isthmus, and descending aorta (DAO). Interobserver and intraobserver variability, gender differences, the relationship between aortic cross-sectional areas and age, and the ratio to the DAO were also examined. The area ratio to the DAO was also examined in the group with coarctation of the aorta. Results A total of 65 patients and 365 measurable aortic segments were included in the analysis (55 normal controls and 10 patients with coarctation of aorta). Interobserver and intraobserver variability was limited (aside from measurements of the sinotubular junction). There were no gender differences in age and the cross-sectional areas of the different aortic segments. In the group of normal controls, the cross-sectional area of each aortic segment was highly correlated with age (all >0.90, P< .001). The reference curves and formulas for aortic cross-sectional area by age were also determined for further clinical use. In the normal controls, the <95% confidence intervals of the ratios of aortic isthmus to DAO, distal arch to DAO, and proximal arch to DAO were approximately 0.6, 0.8, and 1.0, respectively. In addition, in the group with coarctation, all area ratios of aortic isthmus to DAO were <0.6, which was significantly different from the group of normal controls (P< .001). The area ratios of distal arch to DAO and proximal arch to DAO were also significantly different between two groups (P< .001 for both). Conclusions Measurement of aortic area was reproducible. The established reference curves and formulas and minimal area ratios were convenient for further clinical use.
Academic radiology, Volume 20, pp 10-15; https://doi.org/10.1016/j.acra.2012.07.012
Previous work suggests that ascending aortic (AsAo) dilation can be asymmetric and is potentially related to valve-related blood flow abnormalities. The aim of this study was to investigate the relationship between the aortic valve and AsAo dilation using a quantitative, three-dimensional assessment of aortic shapes. Computed tomographic and magnetic resonance images of the thorax were retrospectively reviewed. Four groups with aortic dilation were studied: those with tricuspid aortic valves (TAVs) with and without stenosis and those with bicuspid aortic valves (BAVs) with and without stenosis. Controls had either TAVs or BAVs but no aortic stenosis or dilation. In additional to standard orthogonal diameters, a unique measurement of AsAo asymmetry was used: the ratio of the greater to lesser curvatures measured using three-dimensional reformats in a "candy-cane" orientation. A total of 105 patients were identified. Ratios of greater to lesser curvature in patients with aortic dilation and nonstenotic TAVs were not significantly different from those in controls (1.69 vs 1.55, P > .20), but the asymmetry reflected by this ratio was markedly increased in patients with aortic dilation and stenotic TAVs (1.94, P < .001). Patients with aortic dilation and BAVs had significantly elevated ratios regardless of the status of the aortic valve (1.96 for nonstenotic and 2.05 for stenotic vs 1.53 for controls, P < .001). Asymmetric AsAo dilation with relative bulging of the greater curvature is linked to aortic stenosis, but it is also seen with nonstenotic BAVs. This suggests that the hemodynamic forces that contribute to aortic dilation are not fully revealed by conventional assessment of the aortic valve.
Academic radiology, Volume 20, pp 73-78; https://doi.org/10.1016/j.acra.2012.07.007
To assess the necessity of intravenous contrast medium for abdominopelvic computed tomography (CT) diagnosis of acute appendicitis (APP) among adult patients with right lower quadrant (RLQ) abdominal pain at emergency department (ED). ED patients with clinical suspicion of APP from RLQ pain for a period of 8 months were enrolled retrospectively. Both pre- and postintravenous contrast-enhanced CT scans were performed for these patients. The visibility of vermiform appendix and specific CT findings of APP were recorded separately for noncontrast CT (NCT) and contrast-enhanced CT (CCT) images without knowledge of the patient's identity and final diagnosis. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CT diagnosis for APP were compared between the two groups. The ease of identifying appendix was also compared. Forty-two (42.0%) of the 100 patients (55 males, 45 females; age range, 16-90 years; mean age, 49.3 years) were APP. There was no significant difference for the visibility of appendix (94% vs. 91%; P = .589) and radiological characters between the CCT and NCT groups. There were significant differences between the two groups for sensitivity (100% vs. 90.5%; P = .036), specificity (94.8% vs. 100%; P = .038), PPV (93.3% vs. 100%; P = .021), NPV (100% vs. 93.5%; P = .021), but no significant difference for accuracy (97% vs. 96%; P = 1). The appendix was easier to detect on CCT than NCT images (P = .013). The diagnostic sensitivity of CCT was significantly better than that of NCT. Intravenous contrast administration could also make doctors easier in indentifying appendixes.
Academic radiology, Volume 20, pp 122-127; https://doi.org/10.1016/j.acra.2012.05.021
The modification of the initial radiology board exam series has as a concerted aim the promotion of subspecialization. Yet, in practice, fellowship-trained radiologists may be assigned to off-hours work in other diagnostic areas. The purpose of this study is to chart the prevalence of after-hour work among the various subspecialties in radiology and to relate those findings to the pertinence of a fourth-year training curriculum devoted to only one imaging discipline. A questionnaire was sent to members of Society of Chairs of Academic Radiology Departments and to directors of the 50 largest American private radiology practices requesting that they list after-hours coverage obligations of their various subspecialists. Academic and private practice response rates were 40.8% (42 of 103) and 42% (21 of 50), respectively. In academic practice, 80% of neuroradiologists, 93% of interventional radiologists, and 84% of pediatric radiologists were not assigned after-hour coverage in other subspecialties. In private practice groups, only 24% of neuroradiologists, 48% of interventional radiologists, and 33% of pediatric radiologists were free of these duties. For other subspecialists, the likelihood of after-hours assignments to other disciplines was not so discrepant between academic and private practices. Residents pursuing an academic career in neuroradiology, interventional radiology, or pediatric radiology could benefit from a full fourth-year experience in their area of subspecialty, whereas a more variegated curriculum would be more suitable for other specialists independent of practice type.
Academic radiology, Volume 20; https://doi.org/10.1016/j.acra.2012.06.016
Academic radiology, Volume 20, pp 132-133; https://doi.org/10.1016/j.acra.2012.06.015
Academic radiology, Volume 20; https://doi.org/10.1016/j.acra.2012.02.024
Academic radiology, Volume 20, pp 25-31; https://doi.org/10.1016/j.acra.2012.07.014
The aim of this study was to evaluate whether matrix metalloproteinase-9 (MMP-9) and myeloperoxidase (MPO) are elevated in patients with nonobstructive coronary artery disease. Eighty-four patients with nonobstructive coronary artery disease (group A) and 90 patients with no coronary plaques (group B) were enrolled. MMP-9 and MPO levels were compared between the two groups. The relationships between these biomarkers and Framingham risk score were analyzed. Receiver-operating characteristic curves were used to evaluate the ability of these biomarkers to predict the presence of coronary artery plaques. The MMP-9 and MPO values in group A were significantly higher than in group B (P < .001). The levels of MMP-9 and MPO showed significant correlations with Framingham risk score (r = 0.796, P < .001, and r = 0.409, P < .001, respectively). The areas under the receiver-operating characteristic curves for MMP-9 and MPO were 0.80 (95% confidence interval, 0.74-0.87) and 0.74 (95% confidence interval, 0.66-0.81), respectively. Levels of MMP-9 and MPO are positively correlated with Framingham risk score. Additionally, in patients with nonobstructive coronary artery disease, elevated levels of MMP-9 and MPO may identify patients at risk for future myocardial infarction or sudden cardiac death.
Academic radiology, Volume 20, pp 79-89; https://doi.org/10.1016/j.acra.2012.07.010
The publisher has not yet granted permission to display this abstract.
Academic radiology, Volume 25, pp 82-87; https://doi.org/10.1016/j.acra.2017.06.015
This study aimed to determine the value of dual-energy thoracic radiography in the diagnosis of pneumothorax considering the reader's experience.Forty patients with a suspected pneumothorax, imaged with dual-energy chest radiographs, were divided into two groups: those with pneumothorax as the final diagnosis (n = 19) and those without (n = 21). The images were analyzed by 36 readers (5 interns, 16 residents, 15 senior physicians) for the presence or absence of pneumothorax during three readout sessions at 2-week intervals: standard images alone (session 1), dual-energy images with bone subtraction alone (session 2), and a combination of the two (session 3).The number of correct responses increased 13.3% between sessions 1 and 2 (P < .001) and 9.4% between sessions 1 and 3 (P < .001). The mean sensitivity for pneumothorax detection was higher in sessions 2 (82%) and 3 (79%) compared to session 1 (70%). There was no statistically significant difference in specificity between the sessions. The number of correct responses for small volume pneumothoraces was higher in sessions 2 (10.6 ± 1.8) and 3 (10.1 ± 2.0) than in session 1 (8.9 ± 2.3), with a statistically significant difference between sessions 1 and 2 (P = .002) and between sessions 1 and 3 (P = .048).Bone subtracted dual-energy thoracic radiographs improve the detection sensitivity of pneumothorax, including in cases of small pneumothoraces, regardless of the reader's level or expertise.
Academic radiology, Volume 24, pp 1482-1490; https://doi.org/10.1016/j.acra.2017.07.001
The study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography.Eighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18-31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5.0 mL/s), and iodine dose (22.8 g). An automatic mAs and low concentration contrast medium (300 mgI/mL) were used in group A, whereas effective mAs was reduced by a factor 0.6 along with HCCM (400 mgI/mL) in group B. Radiation dose was assessed (CT dose index [CTDIvol] and dose length product), and vessel-based objective IQ for various regions of interest (enhancement, noise, signal-to-noise ratio, and contrast-to-noise ratio), subjective IQ, noise, and motion artifacts were analyzed overall and vessel-based with a 5-point Likert scale.The CT attenuation of coronary arteries and image noise in group B were significantly higher than those in group A (ranges: 507.5-548.1 Hounsfield units vs 407.5-444.5 Hounsfield units; and 20.3 ± 8.6 vs 17.7 ± 8.0) (P ≤ 0.0166). There was no significant difference between the two groups in signal-to-noise ratio, contrast-to-noise ratio, and subjective IQ of coronary arteries (29.4-31.7, 30.0-37.0, and medium score of 5 in group A vs 29.4-32.4, 27.7-36.3, and medium score of 5 in group B, respectively, P ≥ 0.1859). Both mean CTDIvol and dose length product in group B were 58% of those of group A.HCCM combined with low tube current allows dose reduction in coronary computed tomography angiography and does not compromise IQ.
Academic radiology, Volume 24, pp 1510-1516; https://doi.org/10.1016/j.acra.2017.06.006
There is little agreement within the radiology literature as to the best single measurement for assessing splenomegaly. In this study, we evaluate the correlation of multiple unidirectional measurements of the spleen with splenic volume in patients with cirrhotic liver morphology on computed tomography (CT).Splenic volume was retrospectively calculated from CT examinations of 179 adult patients, 47 of whom were approved as renal donors, and 132 of whom were referred for various other indications, and were found to have cirrhotic liver morphology on CT. Seven unidimensional measurements (long-axis, cranial-caudal, width, and four measures of thickness) of each spleen were evaluated to identify which most closely correlated with the calculated volume.The splenic width had the best correlation with splenic volume for mild-to-moderate splenomegaly, and the splenic cranial-caudal measurement had the best correlation with splenic volume for massive splenomegaly. Receiver operating characteristic analysis demonstrates that a splenic width measurement of approximately 10.5 cm has a sensitivity of 89% and a specificity of 78% for mild-to-moderate splenomegaly, and a cranial-caudal measurement of 14.6 cm has a sensitivity of 92% and a specificity of 91% for massive splenomegaly.A splenic width threshold of 10.5 cm is the most sensitive (89%) and specific (78%) single measurement for mild-to-moderate splenomegaly in patients with cirrhotic liver morphology, whereas a cranial-caudal height threshold of 14.6 cm is the most sensitive (92%) and specific (91%) single measurement for massive splenomegaly.
Academic radiology, Volume 24, pp 1588-1595; https://doi.org/10.1016/j.acra.2017.06.017
Rationale and Objectives The purpose of this retrospective study was to evaluate the incidence of totally implantable venous access devices, also called ports, implantation and the associated abnormalities in 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography-computed tomography (PET-CT) images for patients with cancer, and to determine the percentage of abnormalities identified in the original reports. Materials and Methods The study aimed to perform a retrospective review of all FDG PET-CT imaging in a 3-year period. Cases of port-associated abnormalities found on the FDG PET-CT images were identified and then correlated with X-ray reports and clinical treatment or follow-up. Results In total, 2442 FDG PET-CT scans were retrospectively reviewed. Among them, 897 (897 of 2442, 36.7%) demonstrated port implantation. Abnormalities, including 22 port fractures (22 of 897, 2.45%), 14 malposition (1.56%), one infection (0.11%), and one embraced by a fibrin sheath or tumor (0.11%) were found. Only the infectious one had clinical symptoms. Among the 22 fractured ports, eight fractured catheters migrated and became dislodged. All of the malpositioned ports, except two in the contralateral subclavian vein, were found in the ipsilateral jugular vein. Both the port infection and the port embraced by a fibrin sheath or tumor occurred at the tips of the devices, which demonstrated FDG uptake in the mediastinal region. Only seven of the 38 (18.42%) images of port abnormalities had been identified in the original reports. Conclusions Based on this study, we recommend that the interpretation of FDG PET-CT scans should include a checklist to record all metallic device implantations and to interpret the whole-body X-ray topography as a standard part of PET-CT image report.
Academic radiology, Volume 24, pp 1526-1534; https://doi.org/10.1016/j.acra.2017.06.011
This study aimed to develop and validate a method for measuring the depth of tumor invasion (DoI) using magnetic resonance imaging (MRI) and to investigate the diagnostic performance of the measured DoI for stratifying tumor (T) classification in patients with distal bile duct cancer according to the new American Joint Committee on Cancer staging system.Fifty-four patients (30 men and 24 women; age range, 43-81 years) with distal bile duct cancer were enrolled. A study coordinator first developed a "provisional method" for measuring DoI on T2-weighted MRI. Subsequently, after compensating for defects, the "improved method" was developed. Two reviewers independently measured DoI and assessed its correlations with the histopathologic reference standard using intraclass correlation coefficient (ICC). The study population was grouped according to the DoI for T classification based on the new staging system for evaluation of diagnostic predictive values.The ICC values between the radiologic and the histopathologic DoI were calculated. Using the "improved method," the ICC for the coordinator's DoI was very good (ICC, 0.885), which was a significantly higher value than that obtained using the "provisional method" (ICC, 0.501, P = .00000); and for two reviewers' DoIs, the ICC values were good (ICC, 0.752 and 0.784, respectively). The overall accuracy of MRI for stratifying bile duct tumors using DoI was 87.0% and 85.2%, respectively.This newly developed method reliably measured DoI on T2-weighted MRI and can be used for preoperative T classification of patients with distal bile duct cancer according to the new staging system.
Academic radiology, Volume 24, pp 1575-1581; https://doi.org/10.1016/j.acra.2017.06.016
The study aimed to investigate whether intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) can differentiate luminal-B from luminal-A breast cancer MATERIALS AND METHODS: Biexponential analyses of IVIM and DCE MRI were performed using a 3.0-T MRI scanner, involving 134 patients with 137 pathologically confirmed luminal-type invasive breast cancers. Luminal-type breast cancer was categorized as luminal-B breast cancer (LBBC, Ki-67 ≧ 14%) or luminal-A breast cancer (LABC, Ki-67 < 14%). Quantitative parameters from IVIM (pure diffusion coefficient [D], perfusion-related diffusion coefficient [D*], and fraction [f]) and DCE MRI (initial percentage of enhancement and signal enhancement ratio [SER]) were calculated. The apparent diffusion coefficient (ADC) was also calculated using monoexponential fitting. We correlated these data with the Ki-67 status.The D and ADC values of LBBC were significantly lower than those of LABC (P = 0.028, P = 0.037). The SER of LBBC was significantly higher than that of LABC (P = 0.004). A univariate analysis showed that a significantly lower D (1.071) values were associated with LBBC (all P values 1.071; odds ratio: 3.0099, 95% confidence interval: 1.4246-6.3593; P = 0.003) value and a lower D (<0.847 × 10(-3) mm(2)/s; odds ratio: 2.6878, 95% confidence interval: 1.0445-6.9162; P = 0.040) value were significantly associated with LBBC, compared to LABC.The SER derived from DCE MRI and the D derived from IVIM are associated independently with the Ki-67 status in patients with luminal-type breast cancer.
Academic radiology, Volume 24, pp 1501-1509; https://doi.org/10.1016/j.acra.2017.06.008
Rationale and Objectives This study aimed to provide decision support for the human expert, to categorize liver metastases into their primary cancer sites. Currently, once a liver metastasis is detected, the process of finding the primary site is challenging, time-consuming, and requires multiple examinations. The proposed system can support the human expert in localizing the search for the cancer source by prioritizing the examinations to probable cancer sites. Materials and Methods The suggested method is a learning-based approach, using computed tomography (CT) data as the input source. Each metastasis is circumscribed by a radiologist in portal phase and in non-contrast CT images. Visual features are computed from these images, combined into feature vectors, and classified using support vector machine classification. A variety of different features were explored and tested. A leave-one-out cross-validation technique was conducted for classification evaluation. The methods were developed on a set of 50 lesion cases taken from 29 patients. Results Experiments were conducted on a separate set of 142 lesion cases taken from 71 patients with four different primary sites. Multiclass categorization results (four classes) achieved low accuracy results. However, the proposed system was found to provide promising results of 83% and 99% for top-2 and top-3 classification tasks, respectively. Moreover, when compared to the experts' ability to distinguish the different metastases, the system shows improved results. Conclusions Automated systems, such as the one proposed, show promising new results and demonstrate new capabilities that, in the future, will be able to provide decision and treatment support for radiologists and oncologists, toward more efficient detection and treatment of cancer.
Academic radiology, Volume 24, pp 1556-1560; https://doi.org/10.1016/j.acra.2017.06.009
This study aimed to determine the impact of interventions designed to reduce screening mammography recall rates on screening performance metrics.We assessed baseline performance for full-field digital mammography (FFDM) and digital breast tomosynthesis mammography (DBT) for a 3-year period before intervention. The first intervention sought to increase awareness of recalls from screening mammography. Breast imagers discussed their perceptions regarding screening recalls and were required to review their own recalled cases, including outcomes of diagnostic evaluation and biopsy. The second intervention implemented consensus double reading of all recalls, requiring two radiologists to agree if recall was necessary. Recall rates, cancer detection rates, and positive predictive value 1 (PPV1) were compared before and after each intervention.The baseline recall rate, cancer detection rate, and PPV1 were 11.1%, 3.8/1000, and 3.4%, respectively, for FFDM, and 7.6%, 4.8/1000, and 6.0%, respectively, for DBT. Recall rates decreased significantly to 9.2% for FFDM and to 6.6% for DBT after the first intervention promoting awareness, as well as to 9.9% for FFDM after the second intervention implementing group consensus. PPV1 increased significantly to 5.7% for FFDM and to 9.0% for DBT after the second intervention. Cancer detection rate did not significantly change with the implementation of these interventions. An average of 2.3 minutes was spent consulting for each recall.Reduction in recall rates is desirable, provided performance metrics remain favorable. Our interventions improved performance and could be implemented in other breast imaging settings.
Academic radiology, Volume 24, pp 1463-1467; https://doi.org/10.1016/j.acra.2017.06.012
The American Board of Radiology has adopted a new standardized board examination and the traditional oral examination has been abandoned. Although many programs have changed their educational efforts to reflect the new test format, some faculty members and residents have expressed a desire to keep an oral examination as a component of education and evaluation in radiology residency programs. An oral comprehensive examination including all the appropriate subspecialties was administered to each second year and third year resident in our training program by faculty members. Both the resident examinees and faculty examiners were surveyed after the examination to gauge the perceived value of the experience. Residents were divided in their perceptions of the fairness and utility of an oral examination as a tool to aid in board preparation and as an assessment of their knowledge and communication skill. Faculty members were universal in their endorsement of the oral examination and suggested continued use of the technique. Residents and faculty members have differing perceptions of an oral examination delivered during training to assess knowledge and communication skill. The value of an oral examination in providing actionable feedback to trainees and the possibility of detecting struggling residents made it useful in our training program, and it thus it has been implemented for future years. Whether resident performance measured by this technique is predictive of success on American Board of Radiology examinations remains unclear.
Academic radiology, Volume 24, pp 1570-1574; https://doi.org/10.1016/j.acra.2017.06.014
This study aimed to determine the best screening strategy using automated whole-breast ultrasound and mammography in women with increased breast density or an elevated risk of breast cancer.After an institutional review board waiver was obtained, a retrospective review of 122 cancer cases diagnosed in 3435 women with increased breast density or an elevated risk of breast cancer, screened with mammography and supplemental automated whole-breast ultrasound, was performed. The imaging modality on which each cancer was seen was noted. Screening strategies were postulated. For each screening strategy, rates of advanced cancer diagnosis, with 95% confidence limits, are calculated using the Clopper-Pearson method. Differences in outcomes were calculated using Cochrane Q test and McNemar test for paired observations. Results were expressed for all stages of cancer and for invasive cancers only.When all cancer stages are considered, mammographic screening reduces advanced cancers by 31% over no screening. Ultrasound-only screening results in a 32% reduction. The combination of mammographic and ultrasound screening reduces advanced cancers by 40% (P < .05). Compared to mammographic screening, mammographic plus ultrasound screening reduces advanced-stage cancers by 5.7% (P = 0.03) for all stages and 10.8% (P = 0.02) for invasive cancers.For women with increased breast density or who are at high risk of developing breast cancer, a combination of screening mammography and whole-breast automated ultrasound is superior to mammographic screening. Screening ultrasound alone is also an effective screening strategy.
Academic radiology, Volume 24, pp 1491-1500; https://doi.org/10.1016/j.acra.2017.06.005
This study aimed to investigate the potential of contrast-enhanced magnetic resonance imaging features to differentiate between mass-forming intrahepatic cholangiocellular carcinoma (ICC) and hepatocellular carcinoma (HCC) in cirrhotic livers.This study, performed between 2001 and 2013, included 64 baseline magnetic resonance imaging examinations with pathohistologically proven liver cirrhosis, presenting with either ICC (n = 32) or HCC (n = 32) tumors. To distinguish ICC form HCC tumors, 20 qualitative single-lesion descriptors were evaluated by two readers, in consensus, and statistically classified using the chi-square automatic interaction detection (CHAID) methodology. Diagnostic performance was assessed by a receiver operating characteristic analysis.The CHAID algorithm identified three independent categorical lesion descriptors, including (1) liver capsular retraction; (2) progressive or persistent enhancement pattern or wash-out on the T1-weighted delayed phase; and (3) signal intensity appearance on T2-weighted images that could help to reliably differentiate ICC from HCC, which resulted in an AUC of 0.807, and a sensitivity and specificity of 68.8 and 90.6 (95% confidence interval 75.0-98.0), respectively.The proposed CHAID algorithm provides a simple and robust step-by-step classification tool for a reliable and solid differentiation between ICC and HCC tumors in cirrhotic livers.
Academic radiology, Volume 24, pp 1561-1569; https://doi.org/10.1016/j.acra.2017.06.002
Rationale and Objectives The purpose of this study was to evaluate discrepancy in breast composition measurements obtained from mammograms using two commercially available software methods for systematic trends in overestimation or underestimation compared to magnetic resonance-derived measurements. Materials and Methods An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study was performed to calculate percent breast density (PBD) by quantifying fibroglandular volume and total breast volume derived from magnetic resonance imaging (MRI) segmentation and mammograms using two commercially available software programs (Volpara and Quantra). Consecutive screening MRI exams from a 6-month period with negative or benign findings were used. The most recent mammogram within 9 months was used to derive mean density values from "for processing" images at the per breast level. Bland-Altman statistical analyses were performed to determine the mean discrepancy and the limits of agreement. Results A total of 110 women with 220 breasts met the study criteria. Overall, PBD was not different between MRI (mean 10%, range 1%–41%) and Volpara (mean 10%, range 3%–29%); a small but significant difference was present in the discrepancy between MRI and Quantra (4.0%, 95% CI: 2.9 to 5.0, P < 0.001). Discrepancy was highest at higher breast densities, with Volpara slightly underestimating and Quantra slightly overestimating PBD compared to MRI. The mean discrepancy for both Volpara and Quantra for total breast volume was not significantly different from MRI (p = 0.89, 0.35, respectively). Volpara tended to underestimate, whereas Quantra tended to overestimate fibroglandular volume, with the highest discrepancy at higher breast volumes. Conclusions Both Volpara and Quantra tend to underestimate PBD, which is most pronounced at higher densities. PBD can be accurately measured using automated volumetric software programs, but values should not be used interchangeably between vendors.
Academic radiology, Volume 24, pp 1055-1057; https://doi.org/10.1016/j.acra.2017.06.004
Academic radiology, Volume 24, pp 1380-1386; https://doi.org/10.1016/j.acra.2017.05.018
We aimed to compare the contrast enhancement between tumor and mammary-gland tissue to distinguish lesions in the super-early phase, during which minimal contrast media uptake is observed in mammary-gland tissue.Dynamic magnetic resonance imaging, including the super-early phase with bolus tracking (BT) method (to determine the optimal imaging start time), was performed by using identical parameters to obtain transverse fat-suppressed T1-weighted images of both breasts. The percent enhancement (PE) and the contrast ratio (CR) indicators for tumor and mammary-gland tissue were assessed in each dynamic phase.The PE values of the tumor were 62.4% and 151.6%, and those of the mammary gland were 0.3% and 20.7% in the super-early and early phases, respectively. Therefore, virtually no background parenchymal enhancement was observed in the super-early phase. The variation in the PE values during the super-early phase was significantly smaller when the values were determined with the BT method (P < .05). The CR was highest in the early phase, and the CR in the super-early phase was lower than in the other phases. Early-phase PE and CR were significantly higher in invasive cancer cases than in noninvasive cancer cases (P < .01). A significant difference in the imaging start time was observed for the anatomic side factor by the BT method.Background parenchymal enhancement almost never appeared in the super-early phase, but the CR was lower in the super-early phase than in the early phase. The BT method allowed for an optimal imaging start time for the super-early phase and yielded images with less deviation of contrast enhancement.
Academic radiology, Volume 25; https://doi.org/10.1016/j.acra.2017.06.001
Academic radiology, Volume 24, pp 1318-1324; https://doi.org/10.1016/j.acra.2017.03.018
PowerPoint software (Microsoft, Redmond, WA) has become a popular tool for creating and displaying electronic presentations. The "hyperlink" function in PowerPoint allows users to advance from one slide to another slide in the presentation when they click on a predetermined word, shape, or image, thereby allowing for a more dynamic and interactive experience than can be obtained with serial presentation of slides alone. The objective of this article is to provide a tutorial describing the necessary steps to create hyperlinks and incorporate them in a variety of ways into a PowerPoint presentation. Hyperlinks can turn a passive learning experience into an active one by allowing the participant to become more engaged with the presentation.
Academic radiology, Volume 24, pp 768-771; https://doi.org/10.1016/j.acra.2016.08.012
Scholars have identified two distinct ways of thinking. This "Dual Process Theory" distinguishes a fast, nonanalytical way of thinking, called "System 1," and a slow, analytical way of thinking, referred to as "System 2." In radiology, we use both methods when interpreting and reporting images, and both should ideally be emphasized when educating our trainees. This review provides practical tips for improving radiology education, by enhancing System 1 and System 2 thinking among our trainees.