Dose Length Products for the 10 Most Commonly Ordered CT Examinations in Adults: Analysis of Three Years of the ACR Dose Index Registry

Should Dual-Energy Computed Tomography Pulmonary Angiography Replace Single-Energy Computed Tomography Pulmonary Angiography in Pregnant and Postpartum Patients?

OBJECTIVE

The study aims to compare single-energy (SE) and dual-energy (DE) computed tomography pulmonary angiography (CTPA) for evaluation of suspected pulmonary embolism in pregnant and postpartum patients.

MATERIALS AND METHODS

Our study included 59 CTPA performed in pregnant/postpartum women (study group) comprised of 38 SE-CTPA and 21 DE-CTPA. The control group of 21 age- and weight-matched nonpregnant/nonpostpartum women underwent DE-CTPA. Two radiologists assessed pulmonary arterial enhancement, image quality, and artifacts. κ Test and analysis of variance were performed.

RESULTS

Fourteen of 38 pregnant/postpartum women (37%) had suboptimal SE-CTPA compared with just 10% (2/21) suboptimal DE-CTPA studies (P = 0.02). Mean Hounsfield unit (HU) in the pulmonary trunk was 550 ± 68 HU in the DE-CTPA pregnant/postpartum group and 245 ± 12 HU in the SE-CTPA (P < 0.001). The mean volume computed tomography dose index in the pregnant/postpartum patients for DE-CTPA and SE-CTPA were 9 ± 2 and 19 ± 8 mGy, respectively (P < 0.001).

CONCLUSIONS

Dual-energy CTPA substantially increased arterial enhancement for evaluation of pulmonary embolism in pregnant and postpartum women compared with SE-CTPA.

Report of the ACR's Economics Committee on Value-Based Payment Models

A major outcome of the current health care reform process is the move away from unrestricted fee-for-service payment models toward those that are based on the delivery of better patient value and outcomes. The authors' purpose, therefore, is to critically evaluate and define those components of the overall imaging enterprise that deliver meaningful value to both patients and referrers and to determine how these components might be measured and quantified. These metrics might then be used to lobby providers and payers for sustainable payment solutions for radiologists and radiology services. The authors evaluated radiology operations and services using the framework of the imaging value chain, which divides radiology service into a number of discrete value-added activities, which ultimately deliver the primary product, most often the actionable report for diagnostic imaging or an effective outcome for interventional radiology. These value activities include scheduling and imaging appropriateness and stewardship, patient preparation, protocol design, modality operations, reporting, report communication, and clinical follow-up (eg, mammography reminder letters). Two further categories are hospital or health care organization citizenship and examination outcome. Each is discussed in turn, with specific activities highlighted.

Evaluation of Kidney Stones with Reduced-Radiation Dose CT: Progress from 2011-2012 to 2015-2016-Not There Yet

Purpose To determine if the use of reduced-dose computed tomography (CT) for evaluation of kidney stones increased in 2015-2016 compared with that in 2011-2012, to determine variability in radiation exposure according to facility for this indication, and to establish a current average radiation dose for CT evaluation for kidney stones by querying a national dose registry. Materials and Methods This cross-sectional study was exempt from institutional review board approval. Data were obtained from the American College of Radiology dose registry for CT examinations submitted from July 2015 to June 2016. Study descriptors consistent with single-phase unenhanced CT for evaluation of kidney stones and associated RadLex® Playbook identifiers (RPIDs) were retrospectively identified. Facilities actively submitting data on kidney stone-specific CT examinations were included. Dose metrics including volumetric CT dose index, dose-length product, and size-specific dose estimate, when available, were reported, and a random effects model was run to account for clustering of CT examinations at facilities. A z-ratio was calculated to test for a significant difference between the proportion of reduced-radiation dose CT examinations (defined as those with a dose-length product of 200 mGy · cm or less) performed in 2015-2016 and the proportion performed in 2011-2012. Results Three hundred four study descriptors for kidney stone CT corresponding to data from 328 facilities that submitted 105 334 kidney stone CT examinations were identified. Reduced-dose CT examinations accounted for 8040 of 105 334 (7.6%) CT examinations, a 5.6% increase from the 1010 of 49 903 (2%) examinations in 2011-2012 (P < .001). Mean overall dose-length product was 689 mGy · cm (95% confidence interval: 667, 712), decreased from the mean of 746 mGy · cm observed in 2011-2012. Median facility dose-length product varied up to sevenfold, from less than 200 mGy · cm to greater than 1600 mGy · cm. Conclusion Use of reduced-radiation dose CT for evaluation of kidney stones has increased since 2011-2012, but remains low; variability of radiation dose according to facility continues to be wide. National mean CT radiation exposure for evaluation of renal colic during 2015-2016 decreased relative to 2011-2012 values, but remained well above what is reasonably achievable. ^© RSNA, 2017.

Cardiovascular imaging environment: will the future be cloud-based?

INTRODUCTION

In cardiovascular CT and MR imaging large datasets have to be stored, post-processed, analyzed and distributed. Beside basic assessment of volume and function in cardiac magnetic resonance imaging e.g., more sophisticated quantitative analysis is requested requiring specific software. Several institutions cannot afford various types of software and provide expertise to perform sophisticated analysis. Areas covered: Various cloud services exist related to data storage and analysis specifically for cardiovascular CT and MR imaging. Instead of on-site data storage, cloud providers offer flexible storage services on a pay-per-use basis. To avoid purchase and maintenance of specialized software for cardiovascular image analysis, e.g. to assess myocardial iron overload, MR 4D flow and fractional flow reserve, evaluation can be performed with cloud based software by the consumer or complete analysis is performed by the cloud provider. However, challenges to widespread implementation of cloud services include regulatory issues regarding patient privacy and data security. Expert commentary: If patient privacy and data security is guaranteed cloud imaging is a valuable option to cope with storage of large image datasets and offer sophisticated cardiovascular image analysis for institutions of all sizes.

Imaging wisely: patient safety in CT

The past decade has seen a significant growth in diagnostic CT imaging as a direct result of the clinical value provided by CT imaging. At the same time, many new techniques and resources are now available to make CT imaging safe. This article presents the basics of CT dosimetry and their usage in clinical practices, methods to implement CT dose reduction, followed by a summary of legislation, and guidelines related to patient safety in diagnostic CT imaging. Also, CT radiation dose diagnostic reference levels from published regional and national surveys are reviewed and applied in a CT dose tracking and monitoring program.