Evaluation of particulate 137Cs discharge from a mountainous forested catchment using reservoir sediments and sinking particles

Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Hironori Funaki, Kazuya Yoshimura, Kazuyuki Sakuma, Shatei Iri, Yoshihiro Oda
The time and size dependencies of particulate ¹³⁷Cs concentrations in a reservoir were investigated to evaluate the dynamics of ¹³⁷Cs pollution from a mountainous forested catchment. Sediment and sinking particle samples were collected using a vibracorer and a sediment trap at the Ogaki Dam Reservoir in Fukushima, which is located in the heavily contaminated area that formed as a result of the Fukushima Dai-ichi Nuclear Power Plant accident of 2011. The inventory of ¹³⁷Cs discharged into the reservoir during the post-accident period (965 days) was estimated to be approximately 3.0 × 10¹²–3.9 × 10¹² Bq, which is equivalent to 1.1%–1.4% of the initial estimated catchment inventory. The particulate ¹³⁷Cs concentration showed a decline with time, but the exponent value between the specific surface area and the ¹³⁷Cs concentration for the fine-sized (<63 μm) particle fraction remained almost constant from the immediate aftermath of the accident. These quantitative findings obtained by reconstructing the contamination history of particulate ¹³⁷Cs in reservoir sediments and sinking particles have important implications for the evaluation of ¹³⁷Cs dynamics in mountainous forested catchments.



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Information architecture for a patient-specific dashboard in head and neck tumor boards

Abstract

Purpose

Overcoming the flaws of current data management conditions in head and neck oncology could enable integrated information systems specifically tailored to the needs of medical experts in a tumor board meeting. Clinical dashboards are a promising method to assist various aspects of the decision-making process in such cognitively demanding scenarios. However, in order to provide extensive and intuitive assistance to the participating physicians, the design and development of such a system have to be user-centric. To accomplish this task, conceptual methods need to be performed prior to the technical development and integration stages.

Methods

We have conducted a qualitative survey including eight clinical experts with different levels of expertise in the field of head and neck oncology. According to the principles of information architecture, the survey focused on the identification and causal interconnection of necessary metrics for information assessment in the tumor board.

Results

Based on the feedback by the clinical experts, we have constructed a detailed map of the required information items for a tumor board dashboard in head and neck oncology. Furthermore, we have identified three distinct groups of metrics (patient, disease and therapy metrics) as well as specific recommendations for their structural and graphical implementation.

Conclusion

By using the information architecture, we were able to gather valuable feedback about the requirements and cognitive processes of the tumor board members. Those insights have helped us to develop a dashboard application that closely adapts to the specified needs and characteristics, and thus is primarily user-centric.

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Does Enhancement or Perfusion on Preprocedure CT Predict Outcomes After Embolization of Hepatocellular Carcinoma?

Publication date: Available online 27 March 2018
Source:Academic Radiology
Author(s): Alessandra Borgheresi, Adrian Gonzalez-Aguirre, Karen T. Brown, George I. Getrajdman, Joseph P. Erinjeri, Anne Covey, Hooman Yarmohammadi, Etay Ziv, Constantinos T. Sofocleous, Franz Edward Boas
Rationale and ObjectiveThe objective of this study was to evaluate whether quantitative enhancement or perfusion measurements on preprocedure triphasic computed tomography (CT) can be used to predict response or overall survival after embolization of hepatocellular carcinoma.Materials and MethodsThe institutional review board approved this retrospective review of 63 patients with hepatocellular carcinoma treated with particle embolization between March 2009 and December 2014. Quantitative enhancement and perfusion measurements were performed on the target tumor and the background liver on the triphasic CT performed before treatment. Microvascular invasion (MVI) and degree of differentiation were determined from a core biopsy specimen. Quantitative enhancement and perfusion values were then correlated with pathology (two-tailed t test), response to embolization on modified Response Evaluation Criteria In Solid Tumors (two-tailed t test), and overall survival after embolization (Cox proportional hazards model).ResultsArterial enhancement did not predict immediate response or overall survival after embolization. The degree of differentiation or presence of MVI also did not predict immediate response or overall survival after embolization. However, high hepatic artery coefficient or low portal vein coefficient, both in the tumor (P = .011 and P = .004) and in the background liver (P = .015 and P = .009), were associated with worse survival. Hepatic artery coefficient, both in the tumor (P = .025) and in the background liver (P = .013), were independent predictors of survival in a multivariate model including the Child-Pugh score and the BCLC stage.ConclusionsTumor and liver perfusion parameters estimated from preprocedure triphasic CT were predictive of survival after embolization. Arterial-phase enhancement and histology (degree of differentiation or MVI) did not predict immediate response or overall survival after particle embolization.



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Relationship between Background Parenchymal Enhancement on High-risk Screening MRI and Future Breast Cancer Risk

Publication date: Available online 27 March 2018
Source:Academic Radiology
Author(s): Lars J. Grimm, Ashirbani Saha, Sujata V. Ghate, Connie Kim, Mary Scott Soo, Sora C. Yoon, Maciej A. Mazurowski
Rationale and ObjectivesTo determine if background parenchymal enhancement (BPE) on screening breast magnetic resonance imaging (MRI) in high-risk women correlates with future cancer.Materials and MethodsAll screening breast MRIs (n = 1039) in high-risk women at our institution from August 1, 2004, to July 30, 2013, were identified. Sixty-one patients who subsequently developed breast cancer were matched 1:2 by age and high-risk indication with patients who did not develop breast cancer (n = 122). Five fellowship-trained breast radiologists independently recorded the BPE. The median reader BPE for each case was calculated and compared between the cancer and control cohorts.ResultsCancer cohort patients were high-risk because of a history of radiation therapy (10%, 6 of 61), high-risk lesion (18%, 11 of 61), or breast cancer (30%, 18 of 61); BRCA mutation (18%, 11 of 61); or family history (25%, 15 of 61). Subsequent malignancies were invasive ductal carcinoma (64%, 39 of 61), ductal carcinoma in situ (30%, 18 of 61) and invasive lobular carcinoma (7%, 4of 61). BPE was significantly higher in the cancer cohort than in the control cohort (P = 0.01). Women with mild, moderate, or marked BPE were 2.5 times more likely to develop breast cancer than women with minimal BPE (odds ratio = 2.5, 95% confidence interval: 1.3–4.8, P = .005). There was fair interreader agreement (κ = 0.39).ConclusionsHigh-risk women with greater than minimal BPE at screening MRI have increased risk of future breast cancer.



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Gallbladder Scalloping, Mammillated Caudate Lobe, and Inferior Vena Cava Scalloping

Publication date: Available online 27 March 2018
Source:Academic Radiology
Author(s): Mohammad Amarneh, Ahmed Akhter, M. Zak Rajput, Douglas R. LaBrecque, Monzer Abu-Yousef
PurposeWe aimed to present three new ultrasound signs—gallbladder scalloping, mammillated caudate lobe, and inferior vena cava scalloping—and determine their accuracy in diagnosing liver cirrhosis.Materials and MethodsA total of 201 consecutive patients with a history of chronic liver disease who had undergone ultrasound imaging and liver biopsy were identified. A senior ultrasound radiologist blindly reviewed the ultrasound examinations. Specificity, sensitivity, positive predictive value, and negative predictive value of diagnosing cirrhosis were calculated for all evaluated ultrasound signs and selected combinations of signs, using the liver biopsy results as the reference standard.ResultsOf the 201 patients, 152 (76%) had either pathology-proven cirrhosis or significant fibrosis. Caudate lobe hypertrophy was the most specific (88%) and most positive predictor (90%) for cirrhosis, whereas mammillated caudate lobe was the most sensitive (78%). Inferior vena cava scalloping was the most specific (78%) of the three proposed ultrasound signs. When signs were combined, the presence of either gallbladder scalloping or liver surface nodularity was highly sensitive for cirrhosis (87%), whereas the presence of either gallbladder scalloping or inferior vena cava scalloping with caudate lobe hypertrophy was highly specific (93%).ConclusionsGallbladder scalloping, mammillated caudate lobe, and inferior vena cava scalloping are three novel signs that improve the accuracy of ultrasound in diagnosing cirrhosis.



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Impact of a New Adaptive Statistical Iterative Reconstruction (ASIR)-V Algorithm on Image Quality in Coronary Computed Tomography Angiography

Publication date: Available online 27 March 2018
Source:Academic Radiology
Author(s): Gianluca Pontone, Giuseppe Muscogiuri, Daniele Andreini, Andrea I. Guaricci, Marco Guglielmo, Andrea Baggiano, Fabio Fazzari, Saima Mushtaq, Edoardo Conte, Andrea Annoni, Alberto Formenti, Elisabetta Mancini, Massimo Verdecchia, Alessandro Campari, Chiara Martini, Marco Gatti, Laura Fusini, Lorenzo Bonfanti, Elisa Consiglio, Mark G. Rabbat, Antonio L. Bartorelli, Mauro Pepi
Rationale and objectivesA new postprocessing algorithm named adaptive statistical iterative reconstruction (ASIR)-V has been recently introduced. The aim of this article was to analyze the impact of ASIR-V algorithm on signal, noise, and image quality of coronary computed tomography angiography.Materials and MethodsFifty consecutive patients underwent clinically indicated coronary computed tomography angiography (Revolution CT; GE Healthcare, Milwaukee, WI). Images were reconstructed using filtered back projection and ASIR-V 0%, and a combination of filtered back projection and ASIR-V 20%–80% and ASIR-V 100%. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were calculated for left main coronary artery (LM), left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA) and were compared between the different postprocessing algorithms used. Similarly a four-point Likert image quality score of coronary segments was graded for each dataset and compared. A cutoff value of P < .05 was considered statistically significant.ResultsCompared to ASIR-V 0%, ASIR-V 100% demonstrated a significant reduction of image noise in all coronaries (P < .01). Compared to ASIR-V 0%, SNR was significantly higher with ASIR-V 60% in LM (P < .01), LAD (P < .05), LCX (P < .05), and RCA (P < .01). Compared to ASIR-V 0%, CNR for ASIR-V ≥60% was significantly improved in LM (P < .01), LAD (P < .05), and RCA (P < .01), whereas LCX demonstrated a significant improvement with ASIR-V ≥80%. ASIR-V 60% had significantly better Likert image quality scores compared to ASIR-V 0% in segment-, vessel-, and patient-based analyses (P < .01).ConclusionsReconstruction with ASIR-V 60% provides the optimal balance between image noise, SNR, CNR, and image quality.



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The Impact of Interruptions on Chest Radiograph Interpretation

Publication date: Available online 28 March 2018
Source:Academic Radiology
Author(s): Rachel M. Wynn, Jessica L. Howe, Linda C. Kelahan, Allan Fong, Ross W. Filice, Raj M. Ratwani
Rationale and ObjectivesThe objective of this study was to experimentally test the effect of interruptions on image interpretation by comparing reading time and response accuracy of interrupted case reads to uninterrupted case reads in resident and attending radiologists.Materials and MethodsInstitutional review board approval was obtained before participant recruitment from an urban academic health-care system during January 2016–March 2016. Eleven resident and 12 attending radiologists examined 30 chest radiographs, rating their confidence regarding the presence or the absence of a pneumothorax. Ten cases were normal (ie, no pneumothorax present), 10 cases had an unsubtle pneumothorax (ie, readily perceivable by a nonexpert), and 10 cases had a subtle pneumothorax. During three reads of each case type, the participants were interrupted with 30 seconds of a secondary task. The total reading time and the accuracy of interrupted and uninterrupted cases were compared. A mixed-factors analysis of variance was run on reading time and accuracy with experience (resident vs attending) as a between-subjects factor and case type (normal, unsubtle, or subtle) and interruption (interruption vs no interruption) as within-subjects factors.ResultsInterrupted tasks had significantly longer reading times than uninterrupted cases (P = .032). During subtle cases, interruptions reduced accuracy (P = .034), but during normal cases, interruptions increased accuracy (P = .038).ConclusionsInterruptions increased reading times and increased the tendency for a radiologist to conclude that a case is normal for both resident and attending radiologists, demonstrating that interruptions reduce efficiency and introduce patient safety concerns during reads of abnormal cases.



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