Investigating the impact of structured reporting on the linguistic standardization of radiology reports through natural language processing over a 10-year period.

OBJECTIVES: To investigate how a transition from free text to structured reporting affects reporting language with regard to standardization and distinguishability. METHODS: A total of 747,393 radiology reports dictated between January 2011 and June 2020 were retrospectively analyzed. The body and cardiothoracic imaging divisions introduced a reporting concept using standardized language and structured reporting templates in January 2016. Reports were segmented by a natural language processing algorithm and converted into a 20-dimension document vector. For analysis, dimensionality was reduced to a 2D visualization with t-distributed stochastic neighbor embedding and matched with metadata. Linguistic standardization was assessed by comparing distinct report types' vector spreads (e.g., run-off MR angiography) between reporting standards. Changes in report type distinguishability (e.g., CT abdomen/pelvis vs. MR abdomen) were measured by comparing the distance between their centroids. RESULTS: Structured reports showed lower document vector spread (thus higher linguistic similarity) compared with free-text reports overall (21.9 [free-text] vs. 15.9 [structured]; - 27.4%; p < 0.001) and for most report types, e.g., run-off MR angiography (15.2 vs. 1.8; - 88.2%; p < 0.001) or double-rule-out CT (26.8 vs. 10.0; - 62.7%; p < 0.001). No changes were observed for reports continued to be written in free text, e.g., CT head reports (33.2 vs. 33.1; - 0.3%; p = 1). Distances between the report types' centroids increased with structured reporting (thus better linguistic distinguishability) overall (27.3 vs. 54.4; + 99.3 ± 98.4%) and for specific report types, e.g., CT abdomen/pelvis vs. MR abdomen (13.7 vs. 37.2; + 171.5%). CONCLUSION: Structured reporting and the use of factual language yield more homogenous and standardized radiology reports on a linguistic level, tailored to specific reporting scenarios and imaging studies. CLINICAL RELEVANCE: Information transmission to referring physicians, as well as automated report assessment and content extraction in big data analyses, may benefit from standardized reporting, due to consistent report organization and terminology used for pathologies and normal findings. KEY POINTS: • Natural language processing and t-distributed stochastic neighbor embedding can transform radiology reports into numeric vectors, allowing the quantification of their linguistic standardization. • Structured reporting substantially increases reports' linguistic standardization (mean: - 27.4% in vector spread) and distinguishability (mean: + 99.3 ± 98.4% increase in vector distance) compared with free-text reports. • Higher standardization and homogeneity outline potential benefits of structured reporting for information transmission and big data analyses.

Quantifying Radiology Resident Fatigue: Analysis of Preliminary Reports.

Background Workloads in radiology departments have constantly increased over the past decades. The resulting radiologist fatigue is considered a rising problem that affects diagnostic accuracy. Purpose To investigate whether data mining of quantitative parameters from the report proofreading process can reveal daytime and shift-dependent trends in report similarity as a surrogate marker for resident fatigue. Materials and Methods Data from 117 402 radiology reports written by residents between September 2017 and March 2020 were extracted from a report comparison tool and retrospectively analyzed. Through calculation of the Jaccard similarity coefficient between residents' preliminary and staff-reviewed final reports, the amount of edits performed by staff radiologists during proofreading was quantified on a scale of 0 to 1 (1: perfect similarity, no edits). Following aggregation per weekday and shift, data were statistically analyzed by using simple linear regression or one-way analysis of variance (significance level, P < .05) to determine relationships between report similarity and time of day and/or weekday reports were dictated. Results Decreasing report similarity with increasing work hours was observed for day shifts (r = -0.93 [95% CI: -0.73, -0.98]; P < .001) and weekend shifts (r = -0.72 [95% CI: -0.31, -0.91]; P = .004). For day shifts, negative linear correlation was strongest on Fridays (r = -0.95 [95% CI: -0.80, -0.99]; P < .001), with a 16% lower mean report similarity at the end of shifts (0.85 ± 0.24 at 8 am vs 0.69 ± 0.32 at 5 pm). Furthermore, mean similarity of reports dictated on Fridays (0.79 ± 0.35) was lower than that on all other weekdays (range, 0.84 ± 0.30 to 0.86 ± 0.27; P < .001). For late shifts, report similarity showed a negative correlation with the course of workweeks, showing a continuous decrease from Monday to Friday (r = -0.98 [95% CI: -0.70, -0.99]; P = .007). Temporary increases in report similarity were observed after lunch breaks (day and weekend shifts) and with the arrival of a rested resident during overlapping on-call shifts. Conclusion Decreases in report similarity over the course of workdays and workweeks suggest aggravating effects of fatigue on residents' report writing performances. Periodic breaks within shifts potentially foster recovery. © RSNA, 2021.

Revealing the most common reporting errors through data mining of the report proofreading process.

OBJECTIVES: To investigate the most common errors in residents' preliminary reports, if structured reporting impacts error types and frequencies, and to identify possible implications for resident education and patient safety. MATERIAL AND METHODS: Changes in report content were tracked by a report comparison tool on a word level and extracted for 78,625 radiology reports dictated from September 2017 to December 2018 in our department. Following data aggregation according to word stems and stratification by subspecialty (e.g., neuroradiology) and imaging modality, frequencies of additions/deletions were analyzed for findings and impression report section separately and compared between subgroups. RESULTS: Overall modifications per report averaged 4.1 words, with demonstrably higher amounts of changes for cross-sectional imaging (CT: 6.4; MRI: 6.7) than non-cross-sectional imaging (radiographs: 0.2; ultrasound: 2.8). The four most frequently changed words (right, left, one, and none) remained almost similar among all subgroups (range: 0.072-0.117 per report; once every 9-14 reports). Albeit representing only 0.02% of analyzed words, they accounted for up to 9.7% of all observed changes. Subspecialties solely using structured reporting had substantially lower change ratios in the findings report section (mean: 0.2 per report) compared with prose-style reporting subspecialties (mean: 2.0). Relative frequencies of the most changed words remained unchanged. CONCLUSION: Residents' most common reporting errors in all subspecialties and modalities are laterality discriminator confusions (left/right) and unnoticed descriptor misregistration by speech recognition (one/none). Structured reporting reduces overall error rates, but does not affect occurrence of the most common errors. Increased error awareness and measures improving report correctness and ensuring patient safety are required. KEY POINTS: • The two most common reporting errors in residents' preliminary reports are laterality discriminator confusions (left/right) and unnoticed descriptor misregistration by speech recognition (one/none). • Structured reporting reduces the overall the error frequency in the findings report section by a factor of 10 (structured reporting: mean 0.2 per report; prose-style reporting: 2.0) but does not affect the occurrence of the two major errors. • Staff radiologist review behavior noticeably differs between radiology subspecialties.

Response prediction of hepatocellular carcinoma undergoing transcatheter arterial chemoembolization: unlocking the potential of CT texture analysis through nested decision tree models.

OBJECTIVES: To investigate if nested multiparametric decision tree models based on tumor size and CT texture parameters from pre-therapeutic imaging can accurately predict hepatocellular carcinoma (HCC) lesion response to transcatheter arterial chemoembolization (TACE). MATERIALS AND METHODS: This retrospective study (January 2011-September 2017) included consecutive pre- and post-therapeutic dynamic CT scans of 37 patients with 92 biopsy-proven HCC lesions treated with drug-eluting bead TACE. Following manual segmentation of lesions according to modified Response Evaluation Criteria in Solid Tumors criteria on baseline arterial phase CT images, tumor size and quantitative texture parameters were extracted. HCCs were grouped into lesions undergoing primary TACE (VT-lesions) or repeated TACE (RT-lesions). Distinct multiparametric decision tree models to predict complete response (CR) and progressive disease (PD) for the two groups were generated. AUC and model accuracy were assessed. RESULTS: Thirty-eight of 72 VT-lesions (52.8%) and 8 of 20 RT-lesions (40%) achieved CR. Sixteen VT-lesions (22.2%) and 8 RT-lesions (40%) showed PD on follow-up imaging despite TACE treatment. Mean of positive pixels (MPP) was significantly higher in VT-lesions compared to RT-lesions (180.5 vs 92.8, p = 0.001). The highest AUC in ROC curve analysis and accuracy was observed for the prediction of CR in VT-lesions (AUC 0.96, positive predictive value 96.9%, accuracy 88.9%). Prediction of PD in VT-lesions (AUC 0.88, accuracy 80.6%), CR in RT-lesions (AUC 0.83, accuracy 75.0%), and PD in RT-lesions (AUC 0.86, accuracy 80.0%) was slightly inferior. CONCLUSIONS: Nested multiparametric decision tree models based on tumor heterogeneity and size can predict HCC lesion response to TACE treatment with high accuracy. They may be used as an additional criterion in the multidisciplinary treatment decision-making process. KEY POINTS: • HCC lesion response to TACE treatment can be predicted with high accuracy based on baseline tumor heterogeneity and size. • Complete response of HCC lesions undergoing primary TACE was correctly predicted with 88.9% accuracy and a positive predictive value of 96.9%. • Progressive disease was correctly predicted with 80.6% accuracy for lesions undergoing primary TACE and 80.0% accuracy for lesions undergoing repeated TACE.

Enhancing disease awareness for tuberous sclerosis complex in patients with radiologic diagnosis of renal angiomyolipoma: an observational study.

BACKGROUND: Tuberous Sclerosis Complex (TSC) is a genetic disorder, with renal manifestations like angiomyolipoma (AML) occurring in 70-80% of patients. AML usually cause more complications in TCS patients than in non-TSC patients. However, AML patients are not routinely investigated for TSC. Our aim was to retrospectively assess the correlation between radiologically diagnosed AML and TSC. METHODS: All patients were stratified into AML related vs. unrelated to TSC. Correlations were calculated to determine the association between age, AML, and TSC. RESULTS: Complete data were available for 521 patients with renal AML, in 7 of which the concurrent diagnosis of TSC was found. Younger age significantly positively correlated with the prevalence of TSC in AML patients (p <  0.01). 37 (7%) of the 521 patients were within the age-range of 18-40 years, in which TSC occurred in 6 cases, 4 (66.7%) of which presented with multiple, bilateral renal AML (p <  0.05), and 2 (33.3%) of which with a single, unilateral AML (p <  0.05). In patients with AML but without TSC, unilateral AML was found in 83.9% and bilateral AML in 16.1% (p <  0.05). Simple binary logistic regression analysis revealed bilateral AML (OR 33.0; 95% CI 3.2-344.0; p = 0.003) (but not unilateral AML (OR 0.09; 95% CI 0.01-0.88; p = 0.04)) to be a risk factor for TSC. CONCLUSIONS: The presence of bilateral AML in patients within the age-range of 18-40 years should raise suspicion for TSC as the underlying cause. Therefore, our advice is to refer patients with multiple bilateral renal AML for further investigations regarding TSC.

Novices in MRI-targeted prostate biopsy benefit from structured reporting of MRI findings.

PURPOSE: The aim of this study was to investigate whether structured reports (SRs) of prostate MRI results are more suitable than non-structured reports (NSRs) for promoting the more accurate assessment of the location of a single prostate cancer lesion by novices in MRI-targeted biopsy. METHODS: 50 NSRs and 50 SRs describing a single prostatic lesion were presented to 5 novices in MRI-targeted biopsy. The participants were asked to plot the tumor location in a two-dimensional prostate diagram and to answer a questionnaire on the quality of the reports. The accuracy of the plotted tumor position was evaluated with a validated 30-point scoring system that distinguished between "major" and "minor" mistakes. RESULTS: The overall mean score for the accuracy of the tumor plotting was significantly higher for SRs than for NSRs (26.4 vs. 20.7, p < 0.01). The mean numbers of major (1.4 vs. 0.48, p < 0.01) and minor (3.05 vs. 1.15, p < 0.01) mistakes were significantly higher for NSRs than for SRs. Compared with NSRs, SRs received significantly higher ratings for the perceived quality of the summary (4.0 vs. 2.4, p < 0.01) as well as for the overall satisfaction with the report (4.1 vs. 2.1, p < 0.01). CONCLUSION: Novices in MRI-targeted biopsy prefer structured reporting of prostate MRI as an information tool. SRs allow for a more accurate assessment of the location of single prostate cancer lesions. Therefore, structured reporting of prostate MRI may help to foster the learning process of novices in MRI-targeted biopsy.

High spatiotemporal resolution dynamic contrast-enhanced MRI improves the image-based discrimination of histopathology risk groups of peripheral zone prostate cancer: a supervised machine learning approach.

OBJECTIVE: To assess if adding perfusion information from dynamic contrast-enhanced (DCE MRI) acquisition schemes with high spatiotemporal resolution to T2w/DWI sequences as input features for a gradient boosting machine (GBM) machine learning (ML) classifier could better classify prostate cancer (PCa) risk groups than T2w/DWI sequences alone. MATERIALS AND METHODS: One hundred ninety patients (68 ± 9 years) were retrospectively evaluated at 3T MRI for clinical suspicion of PCa. Included were 201 peripheral zone (PZ) PCa lesions. Histopathological confirmation on fusion biopsy was matched with normal prostate parenchyma contralaterally. Biopsy results were grouped into benign tissue and low-, intermediate-, and high-risk groups (Gleason sum score 6, 7, and > 7, respectively). DCE MRI was performed using golden-angle radial sparse MRI. Perfusion maps (Ktrans, Kep, Ve), apparent diffusion coefficient (ADC), and absolute T2w signal intensity were determined and used as input features for building two ML models: GBM with/without perfusion maps. Areas under the receiver operating characteristic curve (AUC) values for correlated models were compared. RESULTS: For the classification of benign vs. malignant and intermediate- vs. high-grade PCa, perfusion information added relevant information (AUC values 1 vs. 0.953 and 0.909 vs. 0.700, p < 0.001 and p = 0.038), while no statistically significant effect was found for low- vs. intermediate- and high-grade PCa. CONCLUSION: Perfusion information from DCE MRI acquisition schemes with high spatiotemporal resolution to ML classifiers enables a superior risk stratification between benign and malignant and intermediate- and high-risk PCa in the PZ compared with classifiers based on T2w/DWI information alone. KEY POINTS: • In the recent guidelines, the role of DCE MRI has changed from a mandatory to recommended sequence. • DCE MRI acquisition schemes with high spatiotemporal resolution (e.g., GRASP) have been shown to improve the diagnostic performance compared with conventional DCE MRI sequences. • Using perfusion information acquired with GRASP in combination with ML classifiers significantly improved the prediction of benign vs. malignant and intermediate- vs. high-grade peripheral zone prostate cancer compared with non-contrast sequences.

Gadoxetate Disodium versus Gadoterate Meglumine: Quantitative Respiratory and Hemodynamic Metrics by Using Compressed-Sensing MRI.

Background Gadoxetate disodium has been associated with various respiratory irregularities at arterial imaging MRI. Purpose To measure the relationship between gadolinium-based contrast agent administration and irregularities by comparing gadoxetate disodium and gadoterate meglumine at free breathing. Materials and Methods This prospective observational cohort study (January 2015 to May 2017) included consecutive abdominal MRI performed with either gadoxetate disodium or gadoterate meglumine enhancement. Participants underwent dynamic imaging by using the golden-angle radial sparse parallel sequence at free breathing. The quantitative assessment evaluated the aortic contrast enhancement, the respiratory hepatic translation, and the k-space-derived respiratory pattern. Analyses of variance compared hemodynamic metrics, respiratory-induced hepatic motion, and respiratory parameters before and after respiratory gating. Results A total of 497 abdominal MRI examinations were included. Of these, 338 participants were administered gadoxetate disodium (mean age, 59 years ± 15; 153 women) and 159 participants were administered gadoterate meglumine (mean age, 59 years ± 17; 85 women). The arterial bolus of gadoxetate disodium arrived later than gadoterate meglumine (19.7 vs 16.3 seconds, respectively; P < .001). Evaluation of the hepatic respiratory translation showed respiratory motion occurring in 70.7% (239 of 338) of participants who underwent gadoxetate-enhanced examinations and in 28.9% (46 of 159) of participants who underwent gadoterate-enhanced examinations (P < .001). The duration of motion irregularities was longer for gadoxetate than for gadoterate (19.2 seconds vs 17.2 seconds, respectively) and the motion irregularities were more severe (P < .001). Both the respiratory frequency and amplitude were shorter for participants administered gadoxetate from the prebolus phase to the late arterial phase compared with gadoterate (P < .001). Conclusion The administration of two different gadolinium-based contrast agents, gadoxetate and gadoterate, at free-breathing conditions potentially leads to respiratory irregularities with differing intensity and onset. © RSNA, 2019 Online supplemental material is available for this article.

Compressed Sensing Radial Sampling MRI of Prostate Perfusion: Utility for Detection of Prostate Cancer.

Purpose To investigate the diagnostic performance of a dual-parameter approach by combining either volumetric interpolated breath-hold examination (VIBE)- or golden-angle radial sparse parallel (GRASP)-derived dynamic contrast agent-enhanced (DCE) MRI with established diffusion-weighted imaging (DWI) compared with traditional single-parameter evaluations on the basis of DWI alone. Materials and Methods Ninety-four male participants (66 years ± 7 [standard deviation]) were prospectively evaluated at 3.0-T MRI for clinical suspicion of prostate cancer. Included were 101 peripheral zone prostate cancer lesions. Histopathologic confirmation at MRI transrectal US fusion biopsy was matched with normal contralateral prostate parenchyma. MRI was performed with diffusion weighting and DCE by using GRASP (temporal resolution, 2.5 seconds) or VIBE (temporal resolution, 10 seconds). Perfusion (influx forward volume transfer constant [Ktrans] and rate constant [Kep]) and apparent diffusion coefficient (ADC) parameters were determined by tumor volume analysis. Areas under the receiver operating characteristic curve were compared for both sequences. Results Evaluated were 101 prostate cancer lesions (GRASP, 61 lesions; VIBE, 40 lesions). In a combined analysis, diffusion and perfusion parameters ADC with Ktrans or Kep acquired with GRASP had higher diagnostic performance compared with diffusion characteristics alone (area under the curve, 0.97 ± 0.02 [standard error] vs 0.93 ± 0.03; P < .006 and .021, respectively), whereas ADC with perfusion parameters acquired with VIBE had no additional benefit (area under the curve, 0.94 ± 0.03 vs 0.93 ± 0.04; P = .18and .50, respectively, for combination of ADC with Ktrans and Kep). Conclusion If used in a dual-parameter model, incorporating diffusion and perfusion characteristics, the golden-angle radial sparse parallel acquisition technique improves the diagnostic performance of multiparametric MRI examinations of the prostate. This effect could not be observed combining diffusing with perfusion parameters acquired with volumetric interpolated breath-hold examination. © RSNA, 2018.

JOURNAL CLUB: Structured Reporting: The Voice of the Customer in an Ongoing Debate About the Future of Radiology Reporting.

OBJECTIVE: The purpose of this survey was to assess the perception, preferences, and expectations of recipients of radiology reports in terms of style and content. MATERIALS AND METHODS: In 2016, 3610 general practitioners and hospital-based physicians in northwestern Switzerland were invited to participate in a survey. The questionnaire consisted of a demographics section, a current satisfaction section, and a section addressing expectations and preferences concerning content and structure. The participants were asked to rate (range of scores, 1-10) four different layouts of radiology reports (text, structured text, tables, images) in terms of comprehensibility and efficiency. RESULTS: A total of 570 participants (132 general practitioners, 438 hospital physicians at five hospitals) completed the survey. Regarding layout preferences, structured text (median, 8) and images (median, 7) rated highest in terms of readability, time saving, and helpfulness in communication with patients compared with tables (median, 5) and unstructured text (median, 4). The participants responded that reports should give normal values as references (60% [344/570] positive), mention normal structures (50% [286/570] positive), and list additional findings in the summary (89% [507/570] positive). Positive ratings for a confidence statement (54% [308/570]), a list of differential diagnoses (89% [507/570]), and a recommendation (66% [377/570]) indicated an active radiologist's role is appreciated. Eighty percent (459/570) of respondents stated a report should allow fast and efficient reading. CONCLUSION: The voice of the customer approach shows referring physicians have distinct expectations and specific but predominantly coherent preferences with regard to radiology reporting. The survey results offer valuable specific feedback and a strong argument in favor of structured reporting.

[Radiological imaging procedures in the diagnosis, clarification and treatment of colorectal cancer]. / Radiologisch bildgebende Verfahren in der Diagnose, Abklärung und Therapiebegleitung des kolorektalen Karzinoms.

Radiological imaging procedures in the diagnosis, clarification and treatment of colorectal cancer Abstract. The therapeutic approaches and possibilities in the treatment of colorectal cancer are becoming increasingly diverse and specialized. This also expands the wishes and requirements for imaging procedures. Radiology and nuclear medicine is an established part of the interdisciplinary tumor board and thus directly involved in the therapy management of patients with colorectal cancer. It is foreseeable that the importance of imaging procedures for increasingly complex and individualized therapy decisions will continue to increase. The article summarizes the current imaging procedures in diagnosis, clarification and further therapy support of colorectal cancer based on current recommendations. In addition, a brief outlook is provided on current developments, expectations and future wishes for imaging procedures.

Affinity Chart Analysis: A Method for Structured Collection, Aggregation, and Response to Customer Needs in Radiology.

OBJECTIVE: The objective of this study is to analyze implementation of the voice-of-the-customer method to assess the current state of image postprocessing and reporting delivered by a radiology department and to plan improvements on the basis of referring physicians' preferences. SUBJECTS AND METHODS: The voice-of-the-customer method consisted of discovery, analysis, and optimization phases. Fifty referring physicians were invited to be interviewed. Interviews addressed the topics of structure, process, outcome, and support. Interviews were dissected into individual statements categorized as fact or feeling. Statements were grouped to find collective voices. Improvements were compiled from affinity charts and were processed by identifying insights. RESULTS: Ninety-four percent (47/50) of physicians participated, generating 352 statements (81 facts and 271 feelings) that subsequently underwent affinity chart clustering. The resultant affinity charts covered distinct themes: "we need you to know us better," "we need you to consider our workflow," "we need more from your services," "we want to review your data in certain ways," and "we want to do more with you." As a result of the insights gained, the following optimizations were implemented: a software application that improves study requesting, performance tracking, study prioritization, and longitudinal data archiving; six prototype reports containing tabulated data and annotated images; two prototype longitudinal reporting templates assessing aneurysm evolution and treatment-induced changes in organ size over time; and a teaching curriculum for trainees. CONCLUSION: This study has shown the clinical feasibility to assess the current state of image postprocessing and reporting and to implement improvements of and investments in image postprocessing and reporting infrastructure on the basis of referring physicians' preferences using the voice-of-the-customer method.

Whole-Body High-Pitch CT Angiography: Strategies to Reduce Radiation Dose and Contrast Volume.

OBJECTIVE: The purpose of this study was to assess the noninferiority of dual-source high-pitch CT angiography (CTA) performed with high-concentration (iopamidol 370) low-volume (60 mL) iodinated contrast material at low voltage (100 kVp) in comparison with dual-source high-pitch CTA with standard-of-care low-concentration (iopamidol 300) standard-volume (75 mL) iodinated contrast material at high voltage (120 kVp) to determine whether use of the high-concentration low-volume method would afford a reduction in radiation dose and contrast volume without negatively affecting vascular opacification. SUBJECTS AND METHODS: This study had three arms. A phantom was used to assess vascular contrast enhancement at different iodine and saline solution dilutions with iopamidol 300 or 370 to compare lower-iodination (iopamidol 300) high-voltage (120 kVp) high-pitch (120 kVp, 250 mAs) imaging with higher-iodination (iopamidol 370) low-voltage (100 kVp) high-pitch (100 kVp, 100-240 mAs) acquisition. Metal-oxide-semiconductor field-effect transistors were placed in an anthropomorphic phantom to extract organ-based radiation profiles, and ANOVA was performed. The study prospectively enrolled 150 patients: 50 patients received 75 mL iopamidol 300, and image acquisition was performed at 120 kVp and 250 mAs; 50 patients received 75 mL iopamidol 370, and acquisition was performed at 100 kVp and 240 mAs; and 50 patients received 60 mL iopamidol, and acquisition was performed at 370 at 100 kVp and 240 mAs. Vascular signal-to-noise ratio was evaluated at 18 anatomic locations. Longitudinal signal-to-noise ratio was used to assess homogeneity of contrast enhancement. Size-specific dose estimates were calculated. Statistical analyses were performed by ANOVA. RESULTS: Noninferiority of high-concentration (iopamidol 370) low-voltage (100 kVp) high-pitch acquisitions compared with low-concentration (iopamidol 300) high-voltage (120 kVp) high-pitch acquisition was achieved at 170 mAs in vitro. Radiation assessment showed significant decreases in radiation dose for the 100-kVp 240-mAs protocol (p < 0.0001). Noninferior vascular contrast (p > 0.280) and luminal homogeneity (p > 0.191) were found for all high-pitch protocols. Significantly decreased radiation dose was observed for the two groups that received 60 and 75 mL of iopamidol 370 at 100 kVp and 240 mAs (p < 0.0001). CONCLUSION: Dual-source high-pitch CTA with high-concentration (iopamidol 370) low-volume (60 mL) iodinated contrast medium and low-voltage acquisition (100 kVp) is noninferior to dual-source high-pitch CTA with low-concentration (iopamidol 300) standard-volume (75 mL) iodinated contrast material at high voltage (120 kVp) and affords simultaneous reduction in radiation dose and contrast volume without negatively affecting vascular contrast enhancement.

Use of Preprocedural MDCT for Cardiac Implantable Electric Device Lead Extraction: Frequency of Findings That Change Management.

OBJECTIVE: Five percent of cardiac implantable electric devices (CIEDs) are removed each year. Percutaneous extraction is preferred but can be complicated if the leads adhere to the vasculature or perforate. The goal of this study is to assess the frequency of findings on dedicated MDCT that alter preprocedural planning for percutaneous CIED extraction. MATERIALS AND METHODS: One hundred patients with CIEDs who underwent MDCT before percutaneous lead extraction were analyzed. Major findings that could preclude percutaneous removal, including lead course and termination, were distinguished from moderately significant findings that could alter but not preclude percutaneous removal, including endofibrosis of leads to the vasculature, lead termination abnormalities, central vein stenosis, or thrombus. Incidental findings were characterized separately. Findings were correlated with preprocedural decisions, the extraction procedure performed, and procedural outcomes. RESULTS: Twenty-six women and 74 men with 125 right ventricular leads, 84 right atrial leads, and 26 coronary venous leads were evaluated. Major findings were present in 7% of patients, including six patients with lead perforation and one with a lead coursing outside a tricuspid annuloplasty ring. Moderately significant findings of endothelial fibrosis were found in 78% of patients. The central veins were narrowed or occluded in 42% of patients, and thrombus was present in 2% of patients. Thirty-six percent of patients had incidental findings, and 4% of patients had unexpected findings requiring immediate inpatient attention. CONCLUSION: MDCT performed before CIED lead extraction is able to identify major and moderately significant findings that can alter either percutaneous extraction or preprocedural planning. The use of dedicated preprocedural MDCT can help to stratify patient risk, guide decision making by the proceduralist, and identify non-catheter-related findings that affect patient management.

Variability in Radiation Dose From Repeat Identical CT Examinations: Longitudinal Analysis of 2851 Patients Undergoing 12,635 Thoracoabdominal CT Scans in an Academic Health System.

OBJECTIVE: The purpose of this study was to conduct longitudinal analyses of radiation dose data from adult patients undergoing clinically indicated, repeat identical thoracoabdominal CT examinations. MATERIALS AND METHODS: Radiation dose data were electronically collected from 2851 subjects undergoing 12,635 repeat identical CT scans (mean number of scans per patient, 4.8; range, 2-33) in one health system. Included CT protocols were chest-abdomen-pelvis with contrast administration (n = 4621 CT studies of 1064 patients), abdomen-pelvis with contrast administration (n = 876 CT studies of 261 patients), renal stone (n = 1053 CT studies of 380 patients), and chest (n = 6085 CT studies of 1146 patients) without contrast administration. A radiation-tracking software infrastructure was adopted to extract data from DICOM headers in PACS. Size-specific dose estimate (SSDE) was calculated. RESULTS: A trend was observed toward global reduction in SSDE values with all protocols investigated (chest-abdomen-pelvis slope, -1.78; abdomen-pelvis slope, -0.82; renal stone slope, -0.83; chest slope, -0.47; p < 0.001 for all comparisons). The intraindividual analyses of radiation dose distribution showed widespread variability in SSDE values across the four protocols investigated (chest-abdomen-pelvis mean coefficient of variance, 14.02 mGy; abdomen-pelvis mean coefficient of variance, 10.26 mGy; renal stone mean coefficient of variance, 34.18 mGy; chest mean coefficient of variance, 6.74 mGy). CONCLUSION: Although there is a trend toward global reduction in radiation doses, this study showed widespread variability in the radiation dose that each patient undergoing identical repeat thoracoabdominal CT protocols absorbs. These data may provide a foundation for the future development of best-practice guidelines for patient-specific radiation dose monitoring.

White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 3: Vascular, Cardiac, Pulmonary, and Musculoskeletal Applications.

This is the third of a series of 4 white papers that represent Expert Consensus Documents developed by the Society of Computed Body Tomography and Magnetic Resonance through its Task Force on dual-energy computed tomography. This paper, part 3, describes computed tomography angiography and thoracic, cardiac, vascular, and musculoskeletal clinical applications. At the end of the discussion of each application category (vascular, cardiac, pulmonary, and musculoskeletal), we present our consensus opinions on the current clinical utility of the application and opportunities for further research.

White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 4: Abdominal and Pelvic Applications.

This is the fourth of a series of 4 white papers that represent expert consensus documents developed by the Society of Computed Body Tomography and Magnetic Resonance through its task force on dual-energy computed tomography. This article, part 4, discusses DECT for abdominal and pelvic applications and, at the end of each, will offer our consensus opinions on the current clinical utility of the application and opportunities for further research.

Regional Mapping of Aortic Wall Stress by Using Deformable, Motion-coherent Modeling based on Electrocardiography-gated Multidetector CT Angiography: Feasibility Study.

Purpose To investigate the feasibility of deformable, motion-coherent modeling based on electrocardiography-gated multidetector computed tomographic (CT) angiography of the thoracic aorta and to evaluate whether quantifiable information on aortic wall stress as a function of patient-specific cardiovascular parameters can be gained. Materials and Methods For this institutional review board-approved, HIPAA-compliant study, thoracic electrocardiography-gated dual-source multidetector CT angiographic images were used from 250 prospectively enrolled patients (150 men, 100 women; mean age, 79 years). On reconstructed 50-phase CT angiographic images, aortic strain and deformation were determined at seven cardiac and aortic locations. One-way analysis of variance was used by assessing the magnitude for longitudinal and axial strain and axial deformation, as well as time-resolved peak and maxima count for longitudinal strain and axial deformation. Interdependencies between aortic strain and deformation with extracted hemodynamic parameters were evaluated. Results With increasing heart rates, there was a significant decrease in longitudinal strain (P = .009, R(2) = 0.95) and a decrease in the number of longitudinal strain peaks (P < .001, R(2) = 0.79); however, a significant increase in axial deformation (P < .001, R(2) = 0.31) and axial strain (P = .009, R(2) = 0.61) was observed. Increasing aortic blood velocity led to increased longitudinal strain (P = .018, R(2) = 0.42) and longitudinal strain peak counts (P = .011, R(2) = 0.48). Pronounced motion in the longitudinal direction limited motion in the axial plane (P < .019, R(2) = 0.29-0.31). Conclusion The results of this study render a clinical basis and provide proof of principle for the use of deformable, motion-coherent modeling to provide quantitative information on physiological motion of the aorta under various hemodynamic circumstances. (©) RSNA, 2016 Online supplemental material is available for this article.

White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 2: Radiation Dose and Iodine Sensitivity.

This is the second of a series of 4 white papers that represent Expert Consensus Documents developed by the Society of Computed Body Tomography and Magnetic Resonance through its task force on dual-energy computed tomography. This paper, part 2, addresses radiation dose and iodine sensitivity in dual-energy computed tomography.

White Paper of the Society of Computed Body Tomography and Magnetic Resonance on Dual-Energy CT, Part 1: Technology and Terminology.

This is the first of a series of 4 white papers that represent Expert Consensus Documents developed by the Society of Computed Body Tomography and Magnetic Resonance through its task force on dual-energy computed tomography (DECT). This article, part 1, describes the fundamentals of the physical basis for DECT and the technology of DECT and proposes uniform nomenclature to account for differences in proprietary terms among manufacturers.