Publications by authors named "Sodickson Aaron"

115 Publications

Advantages of Colour-Coded Dual-Energy CT Venography in Emergency Neuroimaging.

Br J Radiol 2021 Nov 11;94(1127):20201309. Epub 2021 Aug 11.

Harvard Medical School, Boston, MA, USA.

The objective of this Pictorial Review is to describe the use of colour-coded Dual-Energy CT (DECT) to aid in the interpretation of CT Venography (CTV) of the head for emergent indications. We describe a DE CTV acquisition and post-processing technique that can be readily incorporated into clinical workflow. Colour-coded DE CTV may aid the identification and characterization of dural venous sinus abnormalities and other cerebrovascular pathologies, which can improve diagnostic confidence in emergent imaging settings.
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http://dx.doi.org/10.1259/bjr.20201309DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8553188PMC
November 2021

Fat content quantification using dual-energy CT for differentiation of anterior mediastinal lesions from normal or hyperplastic thymus.

Curr Probl Diagn Radiol 2021 Jul 15. Epub 2021 Jul 15.

Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.

Background: Detection of fat content in thymic lesions is crucial to differentiate thymic hyperplasia from thymic tumors or other anterior mediastinal pathologies.

Purpose: To assess the feasibility of dual-energy CT (DECT) fat content quantification for the differentiation of anterior mediastinal lesions from benign thymic lesions and the normal spectrum of the thymus.

Materials And Methods: Chest DECT images of 465 patients (median 61 years, 63% female) were visually evaluated by two radiologists and semiquantitatively scored based on the degree of fatty degeneration ranging from completely fatty (score 0) to predominantly soft-tissue (score 3), and anterior mediastinal mass (score 4). A subset of scans (n =134 including all cases with scores 2-4 and 20 randomly-selected cases from scores 0 and 1) underwent quantitative DECT analysis (fat fraction, iodine density, and conventional CT value). DECT values were compared across the semiquantitative scores.

Results: Results of visual evaluation included 35 with predominantly solid thymus (score 3) and 15 with anterior mediastinal mass (score 4). The most common clinical diagnoses of the 15 masses (including 8 with pathologic confirmation) were metastases (n = 10) and lymphoma (n = 4). CT values in the abnormal thymus were significantly higher than those in score 3 (median: 69.7 HU versus 19.9 HU, P <0.001). There was no significant difference in iodine density values (median: 1.7 mg/ml versus 1 mg/ml, P = 0.09). However, the fat fraction value was significantly lower in the abnormal thymus (score 4) than in the predominantly soft-tissue attenuation thymuses (score 3) (median: 12.8% versus 38.7%, P <0.001). ROC curve analysis showed that fat fraction had an AUC of 0.96 (P <0.001), with a cutoff of <39.2% fat fraction yielding 100% sensitivity and 85% specificity.

Conclusion: DECT fat fraction measurements of the thymus may provide additional value in distinguishing anterior mediastinal lesions from benign thymus. Use of DECT may reduce the need for subsequent imaging evaluation.
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http://dx.doi.org/10.1067/j.cpradiol.2021.06.007DOI Listing
July 2021

Radiation concerns in frequent flyer patients: should imaging history influence decisions about recurrent imaging?

Br J Radiol 2021 Oct 21;94(1126):20210543. Epub 2021 Jul 21.

Brigham and Women's Hospital, Harvard Medical School, Boston, USA.

Radiation risks from diagnostic imaging have captured the attention of patients and medical practitioners alike, yet it remains unclear how these considerations can best be incorporated into clinical decision-making. This manuscript presents a framework to consider these issues in a potentially at-risk population, the so called "frequent flyer" patients undergoing a large amount of recurrent imaging over time. Radiation risks from the low-dose exposures of diagnostic imaging are briefly reviewed, as applied to recurrent exposures. Some scenarios are then explored in which it may be helpful to incorporate knowledge of a patient's imaging history. There is no simple or uniformly applicable approach to these challenging and often nuanced clinical decisions. The complexity and variability of the underlying disease states and trajectories argues against alerting mechanisms based on a simple cumulative dose threshold. Awareness of imaging history may instead be beneficial in encouraging physicians and patients to take the long view, and to identify those populations of frequent flyers that might benefit from alternative imaging strategies.
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http://dx.doi.org/10.1259/bjr.20210543DOI Listing
October 2021

Prevalence of imaging findings of acute pancreatitis in emergency department patients with elevated serum lipase.

Am J Emerg Med 2021 07 9;50:10-13. Epub 2021 Jul 9.

Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, United States of America; Center for Evidence Based Imaging, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 20 Kent Street, Brookline, MA 02445, United States of America.

Purpose: To assess the association of imaging features of acute pancreatitis (AP) with the magnitude of lipase elevation in Emergency Department (ED) patients.

Methods: This Institutional Review Board-approved retrospective study included 509 consecutive patients presenting from 9/1/13-8/31/15 to a large academic ED with serum lipase levels ≥3× the upper limit of normal (ULN) (≥180 U/L). Patients were excluded if they did not have imaging (n = 131) or had a history of trauma, abdominal metastases, altered mental status, or transfer from an outside hospital (n = 190); the final study population was 188 patients. Imaging exams were retrospectively evaluated, and a consensus opinion of two subspecialty-trained abdominal radiologists was used to diagnose AP. Primary outcome was presence of imaging features of AP stratified by lipase level (≥3×-10× ULN and > 10× ULN). Secondary outcome was rate of discordant consensus evaluation compared to original radiologist's report.

Results: 25.0% of patients (47/188) had imaging features of AP. When lipase was >10× ULN (n = 94), patients were more likely to have imaging features of AP (34%) vs. those with mild elevation (16%) (p = 0.0042). There was moderately strong correlation between lipase level and presence of imaging features of AP (r = 0.48, p < 0.0001). Consensus review of CT and MRI images was discordant with the original report in 14.9% (28/188) of cases.

Conclusion: Prevalence of imaging signs of AP in an ED population with lipase ≥3× ULN undergoing imaging is low. However, the probability of imaging features of AP increases as lipase value increases.
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http://dx.doi.org/10.1016/j.ajem.2021.07.015DOI Listing
July 2021

One size does not fit all: Factors associated with increased frequency of radiation overexposure alerts based on fixed-alert thresholds.

Phys Med 2021 Feb 15;82:79-86. Epub 2021 Feb 15.

Center for Evidence-Based Imaging (CEBI), Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.

Objectives: Quantify the expected rate of CT radiation dose alerts for three body regions using accepted radiation dose benchmarks and assess key determinants of alert frequency.

Methods: This IRB-approved retrospective cohort study evaluated consecutive CT examinations performed between July and December 2013 within an academic medical system. CTDI x-ray tube output metrics were compared to the body-region-specific benchmark levels, Achievable Doses (AD), Diagnostic Reference Levels (DRL), and Dose Notification Values (DNV). A logistic regression model for the simulated alerts was fit as a function of the independent predictors: scanner, body region, gender, weight, and age.

Results: For 17,000 exams, the proportion of events triggering alerts increased with patient weight. Significant covariates were scanner, body region, patient weight and patient age (all p < 0.0001). Odds of alert generation for the AD, DRL, and DNV benchmarks increased by 7.6%, 6.6% and 2.9% per kilogram, respectively, and by 0.8%, 1.1% and -2.7% per year of age (all p < 0.0001). Compared to the most highly optimized scanner, odds of alert generation varied by a factor of 595 for AD, 1126 for DRL, and 13 for DNV.

Conclusion: Alert frequency was significantly correlated with weight, age, body region and scanner. Controllable factors include scanner functionality and associated protocol optimization. Patient factors driving alert frequency are predominantly weight, and to a lesser degree, age. Size-agnostic fixed dose thresholds can frequently produce false positive alerts in appropriately performed exams of large patients, while missing opportunities to identify outlier scans of higher-than-expected dose in small patients.
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http://dx.doi.org/10.1016/j.ejmp.2021.02.003DOI Listing
February 2021

Radiologist Reporting and Operational Management for Patients With Suspected COVID-19.

J Am Coll Radiol 2020 08 11;17(8):1056-1060. Epub 2020 Jun 11.

Center for Evidence-Based Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Vice Chair for Quality and Safety, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.

Purpose: The aim of this study was to evaluate the adoption and outcomes of locally designed reporting guidelines for patients with possible coronavirus disease 2019 (COVID-19).

Methods: A departmental guideline was developed for radiologists that specified reporting terminology and required communication for patients with imaging findings suggestive of COVID-19, on the basis of patient test status and imaging indication. In this retrospective study, radiology reports completed from March 1, 2020, to May 3, 2020, that mentioned COVID-19 were reviewed. Reports were divided into patients with known COVID-19, patients with "suspected" COVID-19 (having an order indication of respiratory or infectious signs or symptoms), and "unsuspected patients" (other order indications, eg, trauma or non-chest pain). The primary outcome was the percentage of COVID-19 reports using recommended terminology; the secondary outcome was percentages of suspected and unsuspected patients diagnosed with COVID-19. Relationships between categorical variables were assessed using the Fisher exact test.

Results: Among 77,400 total reports, 1,083 suggested COVID-19 on the basis of imaging findings; 774 of COVID-19 reports (71%) used recommended terminology. Of 574 patients without known COVID-19 at the time of interpretation, 345 (60%) were eventually diagnosed with COVID-19, including 61% (315 of 516) of suspected and 52% (30 of 58) of unsuspected patients. Nearly all unsuspected patients (46 of 58) were identified on CT.

Conclusions: Radiologists rapidly adopted recommended reporting terminology for patients with suspected COVID-19. The majority of patients for whom radiologists raised concern for COVID-19 were subsequently diagnosed with the disease, including the majority of clinically unsuspected patients. Using unambiguous terminology and timely notification about previously unsuspected patients will become increasingly critical to facilitate COVID-19 testing and contact tracing as states begin to lift restrictions.
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http://dx.doi.org/10.1016/j.jacr.2020.06.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7287462PMC
August 2020

Dual energy CT in clinical routine: how it works and how it adds value.

Emerg Radiol 2021 Feb 1;28(1):103-117. Epub 2020 Jun 1.

Division of Emergency Radiology, Brigham and Women's Hospital Department of Radiology, Boston, MA, USA.

Dual energy computed tomography (DECT), also known as spectral CT, refers to advanced CT technology that separately acquires high and low energy X-ray data to enable material characterization applications for substances that exhibit different energy-dependent x-ray absorption behavior. DECT supports a variety of post-processing applications that add value in routine clinical CT imaging, including material selective and virtual non-contrast images using two- and three-material decomposition algorithms, virtual monoenergetic imaging, and other material characterization techniques. Following a review of acquisition and post-processing techniques, we present a case-based approach to highlight the added value of DECT in common clinical scenarios. These scenarios include improved lesion detection, improved lesion characterization, improved ease of interpretation, improved prognostication, inherently more robust imaging protocols to account for unexpected pathology or suboptimal contrast opacification, length of stay reduction, reduced utilization by avoiding unnecessary follow-up examinations, and radiation dose reduction. A brief discussion of post-processing workflow approaches, challenges, and solutions is also included.
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http://dx.doi.org/10.1007/s10140-020-01785-2DOI Listing
February 2021

Bone Marrow Edema at Dual-Energy CT: A Game Changer in the Emergency Department.

Radiographics 2020 May-Jun;40(3):859-874

From the Departments of Radiology (B.G., J.C.M., J.W.U., S.E.S., A.D.S., B.K.) and Orthopedic Surgery (M.J.W.), Brigham and Women's Hospital Emergency Radiology Division, 75 Francis St, Boston, MA 02115.

Dual-energy CT is increasingly being used in the emergency department to help diagnose acute conditions. Its applications include demonstrating bone marrow edema (BME) seen in the setting of occult fractures and other acute conditions. Dual-energy CT acquires data with two different x-ray energy spectra and is able to help differentiate materials on the basis of their differential energy-dependent x-ray absorption behaviors. Virtual noncalcium (VNCa) techniques can be used to suppress the high attenuation of trabecular bone, thus enabling visualization of subtle changes in the underlying attenuation of the bone marrow. Visualization of BME can be used to identify occult or mildly displaced fractures, pathologic fractures, metastases, and some less commonly visualized conditions such as ligamentous injuries or inflammatory arthritis. The authors' major focus is use of dual-energy CT as a diagnostic modality in the setting of trauma and to depict subtle or occult fractures. The authors also provide some scenarios in which dual-energy CT is used to help diagnose other acute conditions. The causes and pathophysiology of BME are reviewed. Dual-energy CT image acquisition and VNCa postprocessing techniques are also discussed, along with their applications in emergency settings. The authors present potential pitfalls and limitations of these techniques and their possible solutions.RSNA, 2020.
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http://dx.doi.org/10.1148/rg.2020190173DOI Listing
April 2021

Dual-Energy CT to Differentiate Small Foci of Intracranial Hemorrhage from Calcium.

Radiology 2020 01 5;294(1):129-138. Epub 2019 Nov 5.

From the Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass.

Background Diagnostic uncertainty in CT of possible intracranial hemorrhage requires short-interval follow-up imaging, resulting in reduced efficiency of care and higher costs. Purpose To quantify the diagnostic performance of dual-energy CT versus simulated single-energy CT in the differentiation of small foci of intracranial hemorrhage from calcium. Materials and Methods Images from consecutive unenhanced dual-energy CT of the head in patients from a single emergency department obtained from December 2014 to April 2016 were reviewed retrospectively for hyperattenuating intracranial foci. Ground truth was established from reference standard comparison CT or MRI. Foci were divided into development and test sets. Development set foci regions of interest were used to derive candidate CT attenuation thresholds for virtual noncalcium (VNCa) and calcium images. Test set foci were used for threshold validation, and diagnostic performance and confidence were evaluated for two readers blinded to final diagnosis. Statistical comparisons were made with exact binomial tests or repeated-measures analysis of variance. Results The study included 137 patients (65 years ± 17; 70 men) with 146 foci. Foci were divided into a development set ( = 105) and a test set ( = 41). Quantitative analysis of the development set produced candidate thresholds of 44 HU for VNCa images and 7 HU for calcium-only images, yielding diagnostic accuracies for the test set of 88% (36 of 41 foci; 95% confidence interval [CI]: 78%, 98%) and 95% (39 of 41 foci; 95% CI: 88%, 100%), respectively. Dual-energy CT improved reader accuracy from 90% (reader 1, 37 of 41 foci; 95% CI: 81%, 99%) and 93% (reader 2, 38 of 41 foci; 95% CI: 85%, 100%) to 100% (both readers, 41 of 41 foci; 95% CI: 100%, 100%). Diagnostic confidence (classifications rated as "certain") increased from 71% (29 of 41 foci; 95% CI: 57%, 85%) to 90% (37 of 41 foci; 95% CI: 81%, 99%) for reader 1 ( = .019) and from 46% (19 of 41 foci; 95% CI: 31%, 62%) to 85% (35 of 41 foci; 95% CI: 75%, 96%) for reader 2 ( = .0001). Conclusion Dual-energy CT showed high diagnostic performance in the differentiation of small foci of intracranial hemorrhage from calcium and improved diagnostic accuracy and confidence in the initial evaluation of suspected hemorrhage. © RSNA, 2019 See also the editorial by Kotsenas in this issue.
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http://dx.doi.org/10.1148/radiol.2019190792DOI Listing
January 2020

Dual-energy CT for routine imaging of the abdomen and pelvis: radiation dose and image quality.

Emerg Radiol 2020 Feb 1;27(1):45-50. Epub 2019 Nov 1.

Department of Radiology, Section of Emergency Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA.

Purpose: To assess the radiation dose and image quality of routine dual energy CT (DECT) of the abdomen and pelvis performed in the emergency department setting, compared with single energy CT (SECT).

Materials And Methods: Seventy-five consecutive routine contrast-enhanced SECT scans of the abdomen and pelvis meeting inclusion criteria were compared with 75 routine contrast-enhanced DECT scans matched by size and patient weight (within 10 lbs), performed on the same dual-source DECT scanner. Cohorts were compared in terms of radiation dose metrics of CT dose index (CTDI) and dose length product (DLP), objective measurements of image quality (signal, noise, and signal-to-noise ratio of a variety of anatomical landmarks), and subjective measurements of image quality scored by two emergency radiologists.

Results: Demographics and patient size were not statistically different between DECT and SECT cohorts. Both average scans CTDI and DLP were significantly lower with DECT than with SECT. Average scan CTDI for SECT was 14.7 mGy (± 6.6) and for DECT was 10.9 mGy (± 3.8) (p < 0.0001). Average scan DLP for SECT was 681.5 mGy cm (± 339.3) and for DECT was 534.8 mGy cm (± 201.9) (p < 0.0001). For objective image quality metrics, for all structures measured, noise was significantly lower and SNR was significantly higher with DECT compared with SECT. For subjective image quality, for both readers, there was no significant difference between SECT and DECT in subjective image quality for soft tissues and vascular structures, or for subjective image noise.

Conclusions: DECT was performed with decreased radiation dose when compared with SECT, demonstrated improved objective measurements of image quality, and equivalent subjective image quality.
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http://dx.doi.org/10.1007/s10140-019-01733-9DOI Listing
February 2020

Image reconstruction for interrupted-beam x-ray CT on diagnostic clinical scanners.

Phys Med Biol 2019 08 7;64(15):155007. Epub 2019 Aug 7.

New York University School of Medicine, New York, NY, United States of America.

Low-dose x-ray CT is a major research area with high clinical impact. Compressed sensing using view-based sparse sampling and sparsity-promoting regularization has shown promise in simulations, but these methods can be difficult to implement on diagnostic clinical CT scanners since the x-ray beam cannot be switched on and off rapidly enough. An alternative to view-based sparse sampling is interrupted-beam sparse sampling. SparseCT is a recently-proposed interrupted-beam scheme that achieves sparse sampling by blocking a portion of the beam using a multislit collimator (MSC). The use of an MSC necessitates a number of modifications to the standard compressed sensing reconstruction pipeline. In particular, we find that SparseCT reconstruction is feasible within a model-based image reconstruction framework that incorporates data fidelity weighting to consider penumbra effects and source jittering to consider the effect of partial source obstruction. Here, we present these modifications and demonstrate their application in simulations and real-world prototype scans. In simulations compared to conventional low-dose acquisitions, SparseCT is able to achieve smaller normalized root-mean square differences and higher structural similarity measures on two reduction factors. In prototype experiments, we successfully apply our reconstruction modifications and maintain image resolution at quarter-dose reduction level. The SparseCT design requires only small hardware modifications to current diagnostic clinical scanners, opening up new possibilities for CT dose reduction.
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http://dx.doi.org/10.1088/1361-6560/ab2df1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6927037PMC
August 2019

Correction to: Spectrum of diagnostic errors in cervical spine trauma imaging and their clinical significance.

Emerg Radiol 2019 Aug;26(4):417

Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.

The published version of this article unfortunately contained a mistake. Author given and family name Alessandrino Francesco was incorrectly interchanged. The correct presentation is given above. The original article has been corrected.
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http://dx.doi.org/10.1007/s10140-019-01692-1DOI Listing
August 2019

SparseCT: System concept and design of multislit collimators.

Med Phys 2019 Jun 6;46(6):2589-2599. Epub 2019 May 6.

Department of Radiology, NYU School of Medicine, New York, NY, 10016, USA.

Purpose: SparseCT, an undersampling scheme for compressed sensing (CS) computed tomography (CT), has been proposed to reduce radiation dose by acquiring undersampled projection data from clinical CT scanners (Koesters et al. in, SparseCT: Interrupted-Beam Acquisition and Sparse Reconstruction for Radiation Dose Reduction; 2017). SparseCT partially blocks the x-ray beam with a multislit collimator (MSC) to perform a multidimensional undersampling along the view and detector row dimensions. SparseCT undersamples the projection data within each view and moves the MSC along the z-direction during gantry rotation to change the undersampling pattern. It enables reconstruction of images from undersampled data using CS algorithms. The purpose of this work is to design the spacing and width of the MSC slits and the MSC motion patterns based on beam separation, undersampling efficiency, and image quality. The development and testing of a SparseCT prototype with the designed MSC will be described in a following paper.

Methods: We chose a few initial MSC designs based on the guidance from two metrics: beam separation and undersampling efficiency. Both beam separation and undersampling efficiency were measured from numerically simulated photon distribution with MSC taken into consideration. Beam separation measures the separation between x-ray beams from consecutive slits, taking into account penumbra effects on both sides of each slit. Undersampling efficiency measures the dose-weighted similarity between penumbra undersampling and binary undersampling, in other words, the effective contribution of the incident dose to the signal to noise ratio of the projection data. We then compared the initially chosen MSC designs in terms of their reconstruction image quality. SparseCT projections were simulated from fully sampled patient projection data according to the MSC design and motion pattern, reconstructed iteratively using a sparsity-enforcing penalized weighted least squares cost function with ordered subsets/momentum algorithm, and compared visually and quantitatively.

Results: Simulated photon distributions indicate that the size of the penumbra is dominated by the size of the focal spot. Therefore, a wider MSC slit and a smaller focal spot lead to increased beam separation and undersampling efficiency. For fourfold undersampling with a 1.2 mm focal spot, a minimum MSC slit width of three detector rows (projected to the detector surface) is needed for beam separation; for threefold undersampling, a minimum slit width of four detector rows is needed. Simulations of SparseCT projection and reconstruction indicate that the motion pattern of the MSC does not have a visible impact on image quality. An MSC slit width of three or four detector rows yields similar image quality.

Conclusion: The MSC is the key component of the SparseCT method. Simulations of MSC designs incorporating x-ray beam penumbra effects showed that for threefold and fourfold dose reductions, an MSC slit width of four detector rows provided reasonable beam separation, undersampling efficiency, and image quality.
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http://dx.doi.org/10.1002/mp.13544DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561820PMC
June 2019

Virtual monoenergetic dual-energy CT for evaluation of hepatic and splenic lacerations.

Emerg Radiol 2019 Aug 8;26(4):419-425. Epub 2019 Apr 8.

Department of Radiology, Division of Emergency Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA, 02215, USA.

Purpose: To evaluate the utility of virtual monoenergetic imaging in assessing hepatic and splenic lacerations and to determine the optimal energy level to maximize injury contrast-to-noise ratio.

Methods: We retrospectively examined 49 contrast-enhanced abdominal CT studies performed on a dual-source dual-energy CT (DECT) scanner with reported liver and/or splenic lacerations. All studies included portal venous phase imaging acquired simultaneously at low (80 or 100 kVp) and high (140 kVp with tin filtration) energy levels. Conventional 120 kVp-equivalent images were generated for routine review by blending the low and high energy acquisitions. Virtual monoenergetic reconstructions were retrospectively generated in 10 keV increments from 40 to 90 keV. Liver or splenic laceration attenuation, background parenchymal attenuation, and noise were measured on each set of monoenergetic and conventional images. Injury-to-parenchyma contrast and contrast-to-noise ratios (CNR) were calculated. Differences between CNR of monoenergetic series and conventional images were assessed with a paired t test.

Results: Liver laceration was identified in 28 patients, and splenic laceration in 22 patients. Background noise was lower at higher monoenergetic levels, with the lowest noise seen at 90 keV, less than that of conventional images (stddev 8.0 for 90 keV and 8.5 for conventional based on noise of uninjured liver/spleen parenchyma, p < 0.001). For both liver and splenic lacerations, injury-to-parenchyma contrast was greater at lower monoenergetic levels, with maximum at 40 keV. Contrast at 40-70 keV was significantly greater than that of conventional images (p < 0.001). Injury-to parenchyma CNR was also greater at 40-70 keV than that of conventional images and with statistical significance. CNR was highest at 40 keV for both liver (6.5 for 40 keV and 5.4 for conventional, p < 0.001) and splenic lacerations (7.5 vs. 5.8, p < 0.001).

Conclusions: DECT virtual monoenergetic imaging at low keV improves injury-to-parenchyma CNR of hepatic and splenic lacerations compared with traditional polyenergetic reconstructions. Specially, the optimal energy level for assessing both was 40 keV.
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http://dx.doi.org/10.1007/s10140-019-01687-yDOI Listing
August 2019

Spectrum of diagnostic errors in cervical spine trauma imaging and their clinical significance.

Emerg Radiol 2019 Aug 31;26(4):409-416. Epub 2019 Mar 31.

Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.

Purpose: To describe and categorize diagnostic errors in cervical spine CT (CsCT) interpretation performed for trauma and to assess their clinical significance.

Methods: All CsCTs performed for trauma with diagnostic errors that came to our attention based on clinical or imaging follow-up or quality assurance peer review from 2004 to 2017 were included. The number of CsCTs performed at our institution during the same time interval was calculated. Errors were categorized as spinal/extraspinal, involving osseous/soft tissue structures, by anatomical site and level. Images were reviewed by a radiologist and two spine surgeons. For each error, the need for surgery, immobilization, CT angiogram of the neck, and MRI was assessed; if any of these were needed, the error was considered clinically significant.

Results: Of an approximate total 59,000 CsCTs, 56 reports containing diagnostic errors were included. Twelve were extraspinal, and 44 were spinal (26 fractures, 15 intervertebral disc protrusions, two subluxations, one lytic bone lesion). The most common sites of spinal fractures were vertebral body (n = 10) and transverse process (n = 8); the most common levels were C5 (n = 8) and C7 (n = 6). All (n = 26) fractures and two atlantooccipital subluxations were considered clinically significant, including three patients who would have required urgent surgical stabilization (two subluxations and one facet fracture). Two transverse processes fractures did not alter the need for surgical intervention/surgical approach, immobilization, or MRI.

Conclusions: In our study, 66% of spinal diagnostic errors on CsCT were considered clinically significant, potentially altering clinical management. Transverse process and vertebral body fractures were commonly missed.
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http://dx.doi.org/10.1007/s10140-019-01685-0DOI Listing
August 2019

Neurosurgical complications: what the radiologist needs to know.

Emerg Radiol 2019 Jun 13;26(3):331-340. Epub 2019 Feb 13.

Harvard Medical School, Boston, MA, USA.

Visits to the emergency department by patients who have recently undergone neurosurgery are a common occurrence, and these patients frequently receive emergent cross-sectional head imaging in order to evaluate for complications. Different neurosurgical approaches may have typical postoperative imaging findings that can be confused with pathology. Furthermore, particular abnormal postoperative imaging findings may signal an evolving complication. It is essential for the radiologist to understand common neurosurgical procedures and their potential complications in order to provide proper diagnostic evaluation of the postoperative neurosurgical patient. The purpose of this review is to assist radiologists in the evaluation of the postoperative neurosurgical patient and educate them on associated complications. Familiarity with common neurosurgical techniques and postoperative complications will help radiologists make the correct diagnosis, communicate effectively with the neurosurgeon, and expedite patient care.
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http://dx.doi.org/10.1007/s10140-019-01672-5DOI Listing
June 2019

Beyond appendicitis: ultrasound findings of acute bowel pathology.

Emerg Radiol 2019 Jun 19;26(3):307-317. Epub 2019 Jan 19.

Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.

Bowel pathology is a common unexpected finding on routine abdominal and pelvic ultrasound. However, radiologists are often unfamiliar with the ultrasound appearance of the gastrointestinal tract due to the underutilization of ultrasound for bowel evaluation in the USA. The purpose of this article is to familiarize radiologists with the characteristic ultrasound features of a variety of bowel pathologies. Basic ultrasound technique for bowel evaluation, ultrasound appearance of normal bowel, and key ultrasound features of common acute bowel abnormalities will be reviewed.
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http://dx.doi.org/10.1007/s10140-019-01670-7DOI Listing
June 2019

Impact Analysis of the Routine Use of Dual-Energy Computed Tomography for Characterization of Incidental Renal Lesions.

J Comput Assist Tomogr 2019 Mar/Apr;43(2):176-182

From the Departments of Radiology and Emergency Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA.

Objective: The aim of this study was to quantify the prevalence of incidental, indeterminate renal lesions on routine contrast-enhanced abdominal computed tomography (CT) and the proportion of such lesions that could be exonerated by dual-energy CT (DECT) postprocessing as benign hyperdense cysts.

Methods: The reports for 2729 consecutive contrast-enhanced DECT scans in the emergency department setting were reviewed for the mention of any renal lesion. For scans with a reported lesion, images were reviewed to assess for the presence of an indeterminate lesion that could not be definitively characterized as benign. All indeterminate lesions were reviewed with DECT postprocessing by 2 radiologists to assess for enhancement and other imaging characteristics and characterized by readers as benign or not definitively benign. Agreement between readers was assessed statistically, and disagreement was resolved by consensus.

Results: Two thousand seven hundred twenty-nine scans were performed in 2406 unique patients; a renal lesion was reported in 805 unique patient scans (33.4%). Review of these 805 scans led to discovery of 137 indeterminate lesions in 125 scans (5.2% of patients). Of the 137 lesions, 70 (51.1%) were classified as benign hyperdense cysts by readers, with the remaining 67 lesions classified as not definitively benign (43 solid masses, 9 Bosniak IIF cysts, 8 Bosniak III cysts, 7 Bosniak IV cysts).

Conclusions: Incidental indeterminate renal lesions are common on routine contrast-enhanced CT. More than half of these lesions could potentially be exonerated with DECT as benign Bosniak II cysts, which could avert the need for further workup in 2.8% of patients undergoing routine abdominal CT.
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http://dx.doi.org/10.1097/RCT.0000000000000828DOI Listing
April 2019

Imaging Features and Management of Stress, Atypical, and Pathologic Fractures.

Radiographics 2018 Nov-Dec;38(7):2173-2192

From the Departments of Radiology (R.A.M., J.C.M., A.S., B.K.) and Orthopedic Surgery (M.J.W., M.F.), Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115.

Traumatic and atraumatic fractures are entities with distinct but often overlapping clinical manifestations, imaging findings, and management protocols. This article is a review of terminology, etiology, and key imaging features that affect management of atraumatic fractures including stress fractures, atypical femoral fractures, and pathologic fractures. The terminology of atraumatic fractures is reviewed, with an emphasis on the distinctions and similarities of stress, atypical, and pathologic fractures. The basic biomechanics of normal bone is described, with an emphasis on the bone remodeling pathway. This framework is used to better convey the shared etiologies, key differences, and important imaging findings of these types of fractures. Next, the characteristic imaging findings of this diverse family of fractures is discussed. For each type of fracture, the most clinically relevant imaging features that guide management by the multidisciplinary treatment team, including orthopedic surgeons, are reviewed. In addition, imaging features are reviewed to help discriminate stress fractures from pathologic fractures in patients with challenging cases. Finally, imaging criteria to risk stratify an impending pathologic fracture at the site of an osseous neoplasm are discussed. Special attention is paid to fractures occurring in the proximal femur because the osseous macrostructure and mix of trabecular and cortical bone of the proximal femur can function as a convenient framework to understanding atraumatic fractures throughout the skeleton. Atraumatic fractures elsewhere in the body also are used to illustrate key imaging features and treatment concepts. RSNA, 2018.
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http://dx.doi.org/10.1148/rg.2018180073DOI Listing
September 2019

Impact of a Health Information Technology-Enabled Appropriate Use Criterion on Utilization of Emergency Department CT for Renal Colic.

AJR Am J Roentgenol 2019 01 7;212(1):142-145. Epub 2018 Nov 7.

1 Center for Evidence-Based Imaging, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115.

Objective: The purpose of this study was to evaluate the impact of an appropriate use criterion (AUC) for renal colic based on local best practice, implemented as electronic clinical decision support (CDS), on the emergency department (ED) use of CT for patients with suspected nephrolithiasis.

Materials And Methods: This retrospective cohort study was performed in the EDs of a level I trauma center (study site) and local comparable hospital (control site). An AUC for patients younger than 50 years with a history of uncomplicated nephrolithiasis presenting with renal colic was developed by an interdisciplinary emergency medicine, emergency radiology, and urology team and embedded as CDS. AUC-consistent CT of ureter requests received no CDS alert. Otherwise, the orderer was alerted to consider a trial of symptomatic control or discharge without CT. A natural language processing tool mined ED notes for visits in September 2010-February 2012 (before AUC implementation) and April 2013-September 2014 (1 year after implementation) for concept unique identifiers of flank tenderness or renal or ureteral pain. Manual review excluded noneligible cases; the others were reviewed by a multidisciplinary team. Chi-square tests were used to assess for CT rate differences, the primary outcome.

Results: The final sample included 467 patients (194 study site) before and 306 (88 study site) after AUC implementation. The study site's CT of ureter rate decreased from 23.7% (46/194) to 14.8% (13/88) (p = 0.03) after implementation of the AUC. The rate at the control site remained unchanged, 49.8% (136/273) versus 48.2% (105/218) (p = 0.3).

Conclusion: Implementing an AUC based on local best practice as CDS may effectively curb potential imaging overuse in a subset of ED patients with renal colic unlikely to have a complicated course or alternative dangerous diagnosis.
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http://dx.doi.org/10.2214/AJR.18.19966DOI Listing
January 2019

Sarcopenia as a tool for preoperative decision-making.

J Trauma Acute Care Surg 2019 02;86(2):377-379

Division of Trauma Burn and Surgical Critical Care Department of Surgery Brigham and Women's Hospital Harvard Medical School Boston, Massachusetts Center for Surgery and Public Health Department of Surgery Brigham and Women's Hospital Harvard Medical School Boston, Massachusetts Harvard T.H. Chan School of Public Health Boston, Massachusetts Division of Emergency Radiology Department of Radiology Brigham and Women's Hospital Harvard Medical School Boston, Massachusetts. Center for Surgery and Public Health Department of Surgery Brigham and Women's Hospital Harvard Medical School Boston, Massachusetts Harvard T.H. Chan School of Public Health Boston, Massachusetts Division of Trauma Burn and Surgical Critical Care Department of Surgery Brigham and Women's Hospital Harvard Medical School Boston, Massachusetts Center for Surgery and Public Health Department of Surgery Brigham and Women's Hospital Harvard Medical School Boston, Massachusetts Harvard T.H. Chan School of Public Health Boston, Massachusetts Division of Emergency Radiology Department of Radiology Brigham and Women's Hospital Harvard Medical School Boston, Massachusetts.

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http://dx.doi.org/10.1097/TA.0000000000002115DOI Listing
February 2019

Is focused magnetic resonance imaging adequate for treatment decision making in acute traumatic thoracic and lumbar spine fractures seen on whole spine computed tomography?

Spine J 2019 03 23;19(3):403-410. Epub 2018 Aug 23.

Department of Orthopedics, Brigham and Women's Hospital, 75 Francis St, Boston, MA 02115, USA.

Purpose: To assess whether a focused magnetic resonance imaging (MRI) limited to the region of known acute traumatic thoracic or lumbar fracture(s) would miss any clinically significant injuries that would change patient management.

Study Design/setting: A multicenter retrospective clinical study.

Patient Sample: Adult patients with acute traumatic thoracic and/or lumbar spine fracture(s).

Outcome Measures: Pathology identified on MRI (ligamentous disruption, epidural hematoma, and cord contusion), outside of the focused zone, an alteration in patient management, including surgical and nonsurgical, as a result of the identified pathology outside the focused zone.

Methods: Records were reviewed for all adult trauma patients who presented to the emergency department between 2008 and 2016 with one or more fracture(s) of the thoracic and/or lumbar spine identified on computed tomography (CT) and who underwent MRI of the entire thoracic and lumbar spine within 10 days. Exclusion criteria were patients with >4 fractured levels, pathologic fractures, isolated transverse, and/or spinous process fractures, prior vertebral augmentation, and prior thoracic or lumbar spine instrumentation. Patients with neurologic deficits or cervical spine fractures were also included. MRIs were reviewed independently by one spine surgeon and one musculoskeletal fellowship-trained emergency radiologist for posterior ligamentous complex (PLC) integrity, vertebral injury, epidural hematoma, and cord contusion. The surgeon also commented on the clinical significance of the pathology identified outside the focused zone. All cases in which pathology was identified outside of the focused zone (three levels above and below the fractures) were independently reviewed by a second spine surgeon to determine whether the pathology was clinically significant and would alter the treatment plan.

Results: In total, 126 patients with 216 fractures identified on CT were included, with a median age of 49 years. There were 81 males (64%). Sixty-two (49%) patients had isolated thoracolumbar junction injuries and 36 (29%) had injuries limited to a single fractured level. Forty-seven (37%) patients were managed operatively. PLC injury was identified by both readers in 36 (29%) patients with a percent agreement of 96% and κ coefficient of 0.91 (95% CI 0.87-0.95). Both readers independently agreed that there was no pathology identified on the complete thoracic and lumbar spine MRIs outside the focused zone in 107 (85%) patients. Injury outside the focused zone was identified by at least one reader in 19 (15%) patients. None of the readers identified PLC injury, cord edema, or noncontiguous epidural hematoma outside the focused zone. Percent agreement for outside pathology between the two readers was 92% with a κ coefficient of 0.60 (95% CI 0.48-0.72). The two spine surgeons independently agreed that none of the identified pathology outside of the focused zone altered management.

Conclusions: A focused MRI protocol of three levels above and below known thoracolumbar spine fractures would have missed radiological abnormality in 15% of patients. However, the pathology, such as vertebral body edema not appreciated on CT, was not clinically significant and did not alter patient care. Based on these findings, the investigators conclude that a focused protocol would decrease the imaging time while providing the information of the injured segment with minimal risk of missing any clinically significant injuries.
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http://dx.doi.org/10.1016/j.spinee.2018.08.010DOI Listing
March 2019

Blunt traumatic vascular injuries of the head and neck in the ED.

Emerg Radiol 2019 Feb 10;26(1):75-85. Epub 2018 Aug 10.

Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.

Cerebrovascular injury is increasingly identified in patients presenting after blunt trauma due to the implementation of screening criteria and advances in noninvasive angiographic imaging by CT. The variable latent time before onset of secondary stroke presents a window of opportunity for prevention, reinforcing the importance of detection of asymptomatic patients via screening. Furthermore, the high morbidity and mortality associated with secondary stroke makes it imperative that radiologists recognize these challenging injuries. This article reviews the epidemiology of and the various proposed screening criteria for blunt cerebrovascular injury. The imaging findings of extra- and intracranial vascular injuries, including arterial and venous trauma, are reviewed along with the grading system. Conservative management with anticoagulation has gained favor over the years with intervention restricted to high-grade injuries such as transection and hemodynamically significant arteriovenous fistula. Many of these injuries also evolve over time, with or without anticoagulation, necessitating imaging follow-up.
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http://dx.doi.org/10.1007/s10140-018-1630-yDOI Listing
February 2019

CT for thoracic and lumbar spine fractures: Can CT findings accurately predict posterior ligament complex injury?

Eur Spine J 2018 12 3;27(12):3007-3015. Epub 2018 Aug 3.

Department of Radiology, Brigham and Women's Hospital, 75 Francis St, Boston, MA, 02115, USA.

Purpose: This study aims to determine whether secondary CT findings can predict posterior ligament complex (PLC) injury in patients with acute thoracic (T) or lumbar (L) spine fractures.

Methods: This is a retrospective study of 105 patients with acute thoracic and lumbar spine fractures on CT, with MRI as the reference standard for PLC injury. Three readers graded CT for facet joint alignment (FJA), widening (FJW), pedicle or lamina fracture (PLF), spinous fracture (SPF), interspinous widening (ISW), vertebral translation (VBT), and posterior endplate fracture (PEF). Univariate and multivariate logistic regression analyses were performed separately for each reader to test for associations between CT and PLC injury, and diagnostic performance of CT was calculated.

Results: Fifty-three of 105 patients had PLC injury by MRI. Statistically significant predictors of PLC injury were VBT, PLF, ISW, and SPF. Using these four CT findings, odds of PLC injury ranged from 3.8 to 5.6 for one positive finding, but increased to 13.6-25.1 for two or more. At least one positive CT finding was found to yield average sensitivity of 82% and specificity 59%, while two or more yielded sensitivity 46% and specificity 88%.

Conclusion: While no individual CT finding is sufficiently accurate to diagnose or exclude PLC injury, greater the number of positive CT findings (VBT, PLF, ISW, and SPF), the higher the odds of PLC injury. The presence of a single abnormal CT finding may warrant confirmatory MRI for PLC injury, while two or more CT findings may have adequate specificity to avoid need for MRI prior to surgical intervention. These slides can be retrieved under Electronic Supplementary Material.
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http://dx.doi.org/10.1007/s00586-018-5712-zDOI Listing
December 2018

Radiation Dose Considerations in Emergent Neuroimaging.

Neuroimaging Clin N Am 2018 Aug;28(3):525-536

Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA. Electronic address:

Computed tomography is often the first-line diagnostic imaging modality in the evaluation of patients with neurologic emergencies. A patient-centered approach to radiation dose management in emergent neuroimaging thus revolves around the appropriate use of computed tomography, including clinical decision support for ordering providers, thoughtful protocol design, the use of available technological advances in computed tomography, and radiation exposure monitoring at a population level. A multifaceted approach can help to minimize radiation exposure to individual patients while preserving diagnostic quality imaging.
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http://dx.doi.org/10.1016/j.nic.2018.03.010DOI Listing
August 2018

Pearls, Pitfalls, and Problems in Dual-Energy Computed Tomography Imaging of the Body.

Radiol Clin North Am 2018 Jul;56(4):625-640

Division of Emergency Radiology, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.

Dual-energy computed tomography (DECT) is an exciting technology that is increasing in routine use and has the potential for significant clinical impact. With the advancement of DECT, it is important for radiologists to be aware of potential challenges with DECT acquisition and postprocessing, and to have a basic knowledge of unique artifacts and diagnostic pitfalls that can occur when interpreting DECT scans and DECT postprocessed images. This article serves as a practical overview of potential problems and diagnostic pitfalls associated with DECT, and steps that can be taken to avoid them.
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http://dx.doi.org/10.1016/j.rcl.2018.03.007DOI Listing
July 2018

Dual energy CT for evaluation of polycystic kidneys: a multi reader study of interpretation time and diagnostic confidence.

Abdom Radiol (NY) 2018 12;43(12):3418-3424

Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA.

Purpose: To compare dual-energy CT (DECT) iodine overlay images with renal mass protocol CT in the evaluation of polycystic kidneys with respect to reading time, diagnostic confidence, and detection of renal lesions that are not definitively benign.

Methods: Following IRB approval, portal venous phase dual-source DECT scans performed between September 2013 and February 2016 from 55 patients (mean age 67 ± 15 years, 31 male, 24 female) with polycystic kidneys (4 or more cysts) were included. For each patient, two image sets were created: (1) DECT post-processed iodine overlay images and (2) simulated renal mass protocol CT images (virtual noncontrast and mixed images). Two radiologists independently retrospectively reviewed both sets at separate time points, evaluating for the presence of lesions that were not definitively benign (enhancing lesions or Bosniak IIF cysts), as well as reading times and Likert scale diagnostic confidence ratings (scaled 1-5) for the presence of non-benign lesions. Reading times were compared with a t test, diagnostic confidence with a McNemar test, and lesion number detection with Cohen's kappa test.

Results: Iodine overlay images were read faster (mean 55 ± 26 s) than renal mass protocol (mean 105 ± 51 s) (p < 0.001). Readers assigned the highest diagnostic confidence rating in 64% using iodine overlay series, compared to 17% using renal mass protocol (p < 0.0001). The proportion of patients with recorded lesions was not significantly different between methods (p = 0.62).

Conclusions: DECT improves lesion assessment in polycystic kidneys by decreasing reading times and increasing diagnostic confidence, without affecting lesion detection rates.
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http://dx.doi.org/10.1007/s00261-018-1674-1DOI Listing
December 2018

Imaging of Acute Conditions of the Perineum.

Radiographics 2018 Jul-Aug;38(4):1111-1130. Epub 2018 Jun 15.

From the Department of Radiology, Division of Emergency Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St, Boston, MA 02115.

A wide range of acute conditions can affect the perineum, from self-limited disease to conditions that are potentially life threatening or contribute to substantial patient morbidity if not promptly diagnosed and appropriately treated. Imaging is essential in the clinical management of perineal disease because it allows accurate anatomic localization of the origin and extent of the disease to be determined. Familiarity with complex perineal anatomy, appropriate use of imaging modalities, and the spectrum of imaging findings seen in acute perineal conditions is crucial for radiologists to make a rapid and accurate diagnosis. Various imaging modalities are available to evaluate acute perineal conditions, each with their own advantages and disadvantages. Computed tomography is used most commonly in the acute care setting because of its widespread availability and rapid image acquisition. Ultrasonography could be used to evaluate superficial and palpable abnormalities and is especially helpful for diagnosis of genital injuries. Magnetic resonance (MR) imaging exhibits superior tissue contrast resolution, provides excellent characterization of conditions, and lacks ionizing radiation. Its role is increasing in the acute care setting; however, MR imaging is not always readily available and is currently reserved for use as a problem-solving technique. Retrograde urethrography is the modality of choice for evaluating traumatic urethral injury. RSNA, 2018.
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http://dx.doi.org/10.1148/rg.2018170151DOI Listing
October 2018

Internal Rotation Traction Radiograph Improves Proximal Femoral Fracture Classification Accuracy and Agreement.

AJR Am J Roentgenol 2018 08 12;211(2):409-415. Epub 2018 Jun 12.

2 Department of Orthopedics, Brigham and Women's Hospital, Boston, MA.

Objective: The objective of this study is to assess the clinical utility of internal rotation traction radiography in the classification of proximal femoral fractures.

Materials And Methods: The study cohort included 78 consecutive patients who were surgically treated for a proximal femoral fracture and for whom preoperative physician-assisted internal rotation traction radiographs of the fractured hip were obtained in addition to standard radiographs. Two radiologists who were blinded to clinical information independently classified each fracture without the traction view and then with the traction view. The radiologists also reported their confidence (expressed as a percentage) in their classifications. The reference standard was the consensus interpretation of intraoperative C-arm fluoroscopic images by two orthopedic surgeons and one radiologist. Classification accuracy was compared using the McNemar test. Subjective confidence and confidence-weighted accuracy were compare using paired t tests. Agreement with the reference standard and interreader agreement were calculated using the kappa statistic and were compared using the z-test after bootstrapping was performed to obtain the standard error.

Results: With the traction view, the pooled accuracy increased from 44.9% to 72.4%, subjective confidence increased from 87% to 94%, and confidence-weighted accuracy increased from 51.7% to 74.3% (p < 0.001). With the traction view, the kappa statistic for agreement with the reference standard increased from 0.530 to 0.791 and from 0.381 to 0.625 for the two readers, and interreader agreement increased from 0.480 to 0.678 (p < 0.001).

Conclusion: The addition of an internal rotation traction radiographic view significantly improves radiologist accuracy and confidence as well as interreader agreement in the classification of proximal femoral fractures, all of which would be expected to best guide appropriate surgical management.
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http://dx.doi.org/10.2214/AJR.17.19258DOI Listing
August 2018

Motion Artifact Reduction From High-Pitch Dual-Source Computed Tomography Pulmonary Angiography.

J Comput Assist Tomogr 2018 Jul/Aug;42(4):623-629

Siemens Medical Solutions USA, Inc, Malvern, PA.

Purpose: The purpose of this study was to compare quantitative and qualitative measures of aortic, cardiac, and respiratory motion artifact between high-pitch dual-source (DS) and single-source (SS) computed tomography pulmonary angiography (CTPA) protocols.

Methods: This institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study retrospectively reviewed 80 non-electrocardiogram-gated CTPA examinations acquired with a second-generation DS system at 100 kVp following 50 mL iodinated contrast injection - 40 consecutive SS and 40 consecutive DS studies. Quantitative measures of aortic, left ventricular, and diaphragmatic motion were recorded as the maximal excursion of a structure's "double image," and 3 independent readers performed qualitative motion assessments. Pulmonary arterial contrast enhancement, image noise, and radiation dose metrics were recorded. Statistical analyses were performed with 1-way analysis of variance and Fisher exact test.

Results: Dual source outperformed SS technique in both quantitative and qualitative measures of motion. Mean distances between motion-artifact double images were reduced with DS protocol at each location (all P ≤ 0.004), and DS examinations were more likely to receive an assessment of no motion in all locations (all P < 0.0001). The DS protocol demonstrated increases in contrast enhancement, although increased image noise resulted in lower enhancement to noise ratio. Mean radiation dose was 60% lower using the DS protocol.

Conclusion: High-pitch DS CTPA significantly reduces artifacts resulting from ascending aortic, cardiac, and diaphragmatic motion.
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http://dx.doi.org/10.1097/RCT.0000000000000736DOI Listing
August 2018
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