A Faster Prostate MRI: Comparing a Novel Denoised, Single-Average T2 Sequence to the Conventional Multiaverage T2 Sequence Regarding Lesion Detection and PI-RADS Score Assessment.

BACKGROUND: The T2 w sequence is a standard component of a prostate MRI examination; however, it is time-consuming, requiring multiple signal averages to achieve acceptable image quality. PURPOSE/HYPOTHESIS: To determine whether a denoised, single-average T2 sequence (T2 -R) is noninferior to the standard multiaverage T2 sequence (T2 -S) in terms of lesion detection and PI-RADS score assessment. STUDY TYPE: Retrospective. POPULATION: A total of 45 males (age range 60-75 years) who underwent clinically indicated prostate MRI examinations, 21 of whom had pathologically proven prostate cancer. FIELD STRENGTH/SEQUENCE: A 3 T; T2 w FSE, DWI with ADC maps, and dynamic contrast-enhanced images with color-coded perfusion maps. T2 -R images were created from the raw data utilizing a single "average" with iterative denoising. ASSESSMENT: Nine readers randomly assessed complete exams including T2 -R and T2 -S images in separate sessions. PI-RADS version 2.1 was used. All readers then compared the T2 -R and T2 -S images side by side to evaluate subjective preference. An additional detailed image quality assessment was performed by three senior level readers. STATISTICAL TESTS: Generalized linear mixed effects models for differences in lesion detection, image quality features, and overall preference between T2 -R and T2 -S sequences. Intraclass correlation coefficients (ICC) were used to assess reader agreement for all comparisons. A significance threshold of P = 0.05 was used for all statistical tests. RESULTS: There was no significant difference between sequences regarding identification of lesions with PI-RADS ≥3 (P = 0.10) or PI-RADS score (P = 0.77). Reader agreement was excellent for lesion identification (ICC = 0.84). There was no significant overall preference between the two sequences regarding image quality (P = 0.07, 95% CI: [-0.23, 0.01]). Reader agreement was good regarding sequence preference (ICC = 0.62). DATA CONCLUSION: Use of single-average, denoised T2 -weighted images was noninferior in prostate lesion detection or PI-RADS scoring when compared to standard multiaverage T2 -weighted images. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 3.

Comparing Survival Outcomes of Patients With LI-RADS-M Hepatocellular Carcinomas and Intrahepatic Cholangiocarcinomas.

BACKGROUND: There is a sparsity of data evaluating outcomes of patients with Liver Imaging Reporting and Data System (LI-RADS) (LR)-M lesions. PURPOSE: To compare overall survival (OS) and progression free survival (PFS) between hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA) meeting LR-M criteria and to evaluate factors associated with prognosis. STUDY TYPE: Retrospective. SUBJECTS: Patients at risk for HCC with at least one LR-M lesion with histologic diagnosis, from 8 academic centers, yielding 120 patients with 120 LR-M lesions (84 men [mean age 62 years] and 36 women [mean age 66 years]). FIELD STRENGTH/SEQUENCE: A 1.5 and 3.0 T/3D T1 -weighted gradient echo, T2 -weighted fast spin-echo. ASSESSMENT: The imaging categorization of each lesion as LR-M was made clinically by a single radiologist at each site and patient outcome measures were collected. STATISTICAL TESTS: OS, PFS, and potential independent predictors were evaluated by Kaplan-Meier method, log-rank test, and Cox proportional hazard model. A P value of <0.05 was considered significant. RESULTS: A total of 120 patients with 120 LR-M lesions were included; on histology 65 were HCC and 55 were iCCA. There was similar median OS for patients with LR-M HCC compared to patients with iCCA (738 days vs. 769 days, P = 0.576). There were no significant differences between patients with HCC and iCCA in terms of sex (47:18 vs. 37:18, P = 0.549), age (63.0 ± 8.4 vs. 63.4 ± 7.8, P = 0.847), etiology of liver disease (P = 0.202), presence of cirrhosis (100% vs. 100%, P = 1.000), tumor size (4.73 ± 3.28 vs. 4.75 ± 2.58, P = 0.980), method of lesion histologic diagnosis (P = 0.646), and proportion of patients who underwent locoregional therapy (60.0% vs. 38.2%, P = 0.100) or surgery (134.8 ± 165.5 vs. 142.5 ± 205.6, P = 0.913). Using multivariable analysis, nonsurgical compared to surgical management (HR, 4.58), larger tumor size (HR, 1.19), and higher MELD score (HR, 1.12) were independently associated with worse OS. DATA CONCLUSION: There was similar OS in patients with LR-M HCC and LR-M iCCA, suggesting that LR-M imaging features may more closely reflect patient outcomes than histology. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 5.

Clinical and imaging predictors of the natural course of bland portal vein thrombus in cirrhotic patients.

BACKGROUND: Portal vein thrombus (PVT) in cirrhotic patients is associated with worsening portal hypertension, leads to increased complexity of necessary interventions such as transjugular liver portosystemic shunt or liver transplantation, and is associated with worse outcomes after liver transplantation. Additionally, there are no established consensus guidelines for management of bland PVT in cirrhotic patients, which currently exists on a spectrum and is patient and provider dependent. PURPOSE: The aim of this study was to determine whether there are associations between key clinical and imaging variables and bland PVT burden over time. MATERIAL AND METHODS: This exploratory, retrospective, single-center study included patients who underwent two or more multiphase CT or MRI examinations between 1/1/2013 and 12/31/2019 and had a diagnosis of PVT. Three readers independently evaluated all index and follow-up examinations for PVT burden using a proposed 8-point scale and the established Yerdel score. Key clinical factors were collected from the electronic medical record. The PVT burden over time and the association of this burden with key clinical and imaging variables were assessed using logistic regression models. RESULTS: 138 patients with cirrhosis and bland PVT were included in the analyses. Median age was 60 years (interquartile range 55-67; 90 men) and median follow-up time was 19.6 months. At baseline, the mean score was 2.31 (± 1.44) and at the final follow-up examination, the mean score was 2.52 (± 1.99). Baseline occlusion level was the only statistically significant association with worsening PVT burden in all four vascular territories (p-value < 0.0001). Anticoagulation status did not have a statistically significant association with change in thrombus burden in any vascular territory or cumulative thrombus burden across all territories (p-value 0.11-0.43). CONCLUSION: In conclusion, our study shows that in cirrhotic patients with bland PVT, the thrombus burden did not change significantly over time and baseline thrombus burden is the only clinical factor significantly associated with increasing burden over time.

Electronic Health Record Closed-Loop Communication Program for Unexpected Nonemergent Findings.

Background Reliance on examination reporting of unexpected imaging findings does not ensure receipt of findings or appropriate follow-up. A closed-loop communication system should include provider and patient notifications and be auditable through the electronic health record (EHR). Purpose To report the initial design of and results from using an EHR-integrated unexpected findings navigator (UFN) program that ensures closed-loop communication of unexpected nonemergent findings. Materials and Methods An EHR-integrated UFN program was designed to enable identification and communication of unexpected findings and aid in next steps in findings management. Three navigators (with prior training as radiologic technologists and sonographers) facilitated communication and documentation of results to providers and patients. Twelve months (October 2019 to October 2020) of results were retrospectively reviewed to evaluate patient demographics and program metrics. Descriptive statistics and correlation analysis were performed by using commercially available software. Results A total of 3542 examinations were reported within 12 months, representing 0.5% of all examinations performed (total of 749 649); the median patient age was 62 years (range, 1 day to 98 years; interquartile range, 23 years). Most patients were female (2029 of 3542 [57%]). Almost half of the examinations submitted were from chest radiography and CT (1618 of 3542 [46%]), followed by MRI and CT of the abdomen and pelvis (1123 of 3542 [32%]). The most common unexpected findings were potential neoplasms (391 of 3542 [11%]). The median time between examination performance and patient notification was 12 days (range, 0-136 days; interquartile range, 13 days). A total of 2127 additional imaging studies were performed, and 1078 patients were referred to primary care providers and specialists. Most radiologists (89%, 63 of 71 respondents) and providers (65%, 28 of 43 respondents) found the system useful and used it most frequently during regular business hours. Conclusion An electronic health record-integrated, navigator-facilitated, closed-loop communication program for unexpected radiologic findings led to near-complete success in notification of providers and patients and facilitated the next steps in findings management. © RSNA, 2021 See also the editorial by Safdar in this issue.

Intravascular Ultrasound-Guided Transvenous Biopsy of Abdominal and Pelvic Targets Difficult to Access by Percutaneous Needle Biopsy: Technique and Initial Clinical Experience.

PURPOSE: To report initial clinical experience with intravascular ultrasound (US)-guided transvenous biopsy (TVB) for perivascular target lesions in the abdomen and pelvis using side-viewing phased-array intracardiac echocardiography catheters. MATERIALS AND METHODS: In this single-institution, retrospective study, 48 patients underwent 50 intravascular US-guided TVB procedures for targets close to the inferior vena cava or iliac veins deemed difficult to access by conventional percutaneous needle biopsy (PNB). In all procedures, side-viewing phased-array intracardiac echocardiography intravascular US catheters and transjugular liver biopsy sets were inserted through separate jugular or femoral vein access sheaths, and 18-gauge core needle biopsy specimens were obtained under real-time intravascular US guidance. Diagnostic yield, diagnostic accuracy, and complications were analyzed. RESULTS: Intravascular US-guided TVB was diagnostic of malignancy in 40 of 50 procedures for a diagnostic yield of 80%. There were 5 procedures in which biopsy was correctly negative for malignancy, with a per-procedure diagnostic accuracy of 90% (45/50). Among the 5 false negatives, 2 patients underwent repeat intravascular US-guided TVB, which was diagnostic of malignancy for a per-patient diagnostic accuracy of 94% (45/48). There were 1 (2%) mild, 2 (4%) moderate, and 1 (2%) severe adverse events, with 1 moderate severity adverse event (venous thrombosis) directly attributable to the intravascular US-guided TVB technique. CONCLUSIONS: Intravascular US-guided TVB performed on difficult-to-approach perivascular targets in the abdomen and pelvis resulted in a high diagnostic accuracy, similar to accepted thresholds for PNB. Complication rates may be slightly higher but should be weighed relative to the risks of difficult PNB, surgical biopsy, or clinical management without biopsy.

Optimizing Identification of Power Injectable Ports on the Scout Images for Multidetector Computed Tomography Procedures.

OBJECTIVE: The objective of this study was to assess the impact of tube voltage and image display on the identification of power ports features on anterior-posterior scout images to inform optimal workflow for multidetector computed tomography (MDCT) examinations. MATERIALS AND METHODS: Four ports, representing variable material composition (titanium/silicone), shapes, and computed tomography (CT) markings, were imaged on an adult anthropomorphic chest phantom using a dual-source MDCT at variable peak tube voltages (80, 100, 120, 150, and Sn150 kVp). Images were reviewed at variable image display setting by 5 blinded readers to assess port features of material composition, shape, and text markings as well as overall preferred image quality. RESULTS: Material composition was correctly identified for all ports by all readers across all kilovoltage-peak settings. The identification by shape was more reliable than CT markers for all but one of the ports. CT marker identification was up to 80% for titanium ports at window level settings optimized for metal (window width, 200; window center, -150) and at a soft tissue setting (window width, 400; window center, 40) for silicone ports. Interreader agreement for best image quality per kilovoltage-peak setting was moderate to substantial for 3 ports (k = 0.5-0.62) but only fair for 1 port (k = 0.27). The highest overall rank for image quality was given unanimously to Sn150 kVp for imaging titanium ports and 100 kVp for silicone ports. CONCLUSIONS: Power port identification on MDCT scout images can be optimized with modification of MDCT scout acquisition and display settings based on the main port material.

MR Enterography of Complicated Crohn Disease: Stricturing and Penetrating Disease.

ABSTRACT: Stricturing and penetrating disease are complications of Crohn disease (CD) that significantly affect patient outcomes. Careful evaluation for such complications is critical to the interpretation of magnetic resonance enterography. This manuscript outlines the key findings related to stricturing and penetrating CD and discusses current understanding of the pathophysiology and prognosis of complicated CD based on the literature.

Automated Structured Reporting for Thyroid Ultrasound: Effect on Reporting Errors and Efficiency.

PURPOSE: To compare the effectiveness of different reporting templates using the ACR Thyroid Imaging Reporting and Data System (TI-RADS) for thyroid ultrasound. METHODS: In this retrospective study, four radiologists implemented ACR TI-RADS while dictating 20 thyroid ultrasounds for each of four different templates: free text, minimally structured, fully structured, fully structured and automated (embedded software automatically sums TI-RADS points, correlates with nodule size, and inserts appropriate recommendation into report impression). In total, 80 reports were constructed per template type. Frequencies of different errors related to ACR TI-RADS were recorded: errors in point assignment, point addition, risk-level assignment, and recommendation. Reporting times were recorded, and a survey about using the template was administered. Differences in error rates were compared using χ2 and Fisher's exact tests, and differences in reporting times were compared using Kruskal-Wallis tests. RESULTS: Across all readers, errors were identified in 27.5% of reports (22 of 80) for the free text template, 28.8% (23 of 80) for the minimally structured template, 18.8% (15 of 80) for the fully structured template, and 0% (0 of 80) for the fully structured and automated template (P < .0001). Frequency of each error type (number assignment, addition, TR categorization, recommendation) decreased across the four templates (P < .0005 to P < .005). Median reporting times for the less complex templates were 210 to 240 seconds, whereas the median automated template reporting time was 180 seconds (P = .41). Radiologists subjectively preferred using the automated template. CONCLUSION: A structured reporting template for thyroid ultrasound that automatically executed steps of ACR TI-RADS resulted in fewer reporting errors for radiologists.

LI-RADS ancillary feature prediction of longitudinal category changes in LR-3 observations: an exploratory study.

PURPOSE: To determine whether LI-RADS ancillary features predict longitudinal LR-3 observation category changes. MATERIALS AND METHODS: This exploratory, retrospective, single-center study with an independent reading center included patients who underwent two or more multiphase CT or MRI examinations for hepatocellular carcinoma assessment between 2011 and 2015. Three readers independently evaluated each observation using CT/MRI LI-RADS v2017, and observations categorized LR-3 using major features only were included in the analysis. Prevalence of major and ancillary features was calculated. After excluding low-frequency (< 5%) features, inter-reader agreement was assessed using intraclass correlation coefficient (ICC). Major and ancillary feature prediction of observation upgrade (to LR-4 or higher) or downgrade (to LR-1 or LR-2) on follow-up imaging was assessed using logistic regression. RESULTS: 141 LR-3 observations in 79 patients were included. Arterial phase hyperenhancement, washout, restricted diffusion, mild-moderate T2 hyperintensity, and hepatobiliary phase hypointensity were frequent enough for further analysis (consensus prevalence 5.0-66.0%). ICCs for inter-reader agreement ranged from 0.18 for restricted diffusion to 0.48 for hepatobiliary phase hypointensity. On follow-up, 40% (57/141) of baseline LR-3 observations remained LR-3. 8% (11/141) were downgraded to LR-2, and 42% (59/141) were downgraded to LR-1. A small number were ultimately upgraded to LR-4 (2%, 3/141) or LR-5 (8%, 11/141). None of the assessed major or ancillary features was significantly associated with observation category change. Longer follow-up time was significantly associated with both observation upgrade and downgrade. CONCLUSION: While numerous ancillary features are described in LI-RADS, most are rarely present and are not useful predictors of LR-3 observation category changes.

Ultrasound-guided non-targeted liver core biopsy: comparison of the efficacy of two different core needle biopsy systems using an ex-vivo animal model and retrospective review of clinical experience.

PURPOSE: To compare the efficacy of two 18-gauge core needle biopsy systems, the Achieve® (Merit Medical) and the Marquee® (BD Bard), using an ex-vivo animal liver model and retrospective review of clinical experience. METHODS: Sixty ex-vivo liver biopsy samples were obtained using the Achieve® (n = 30) and the Marquee® (n = 30) needles. In addition, 20 liver biopsy samples from 20 patients obtained using the Achieve® (n = 10) and Marquee® (n = 10) were compared retrospectively. One pathologist, blinded to needle type, recorded total core length and the number of complete portal triads. Ex vivo measurements were compared using mixed effects linear, logistic, and ordinal regression. In vivo measurements were compared using Student's t-test. RESULTS: For the Achieve® and Marquee® needles, the mean(SD) total core length (mm) of ex vivo samples was 11.0(3.3) and 12.6(3.4), respectively (P = 0.069) and the adequacy rate was 23.3% and 50%, respectively (P = 0.04). Mean number of portal triads of ex vivo samples was 7.2(2.9) and 8.6(3.8), respectively (P = 0.13), and the adequacy rate was 73.3% and 83.3%, respectively (P = 0.32). For in vivo samples, the Achieve® and Marquee® needles demonstrates mean(SD) total core length (mm) of 24.6(7.1) and 32.0(4.6), respectively (P = 0.01), adequacy rate (P = 0.06). Mean number of portal triads was 14.9(4.8) and 19.6(4.1), respectively (P = 0.03), adequacy rate (P = 0.47). CONCLUSIONS: Slightly longer core biopsies were obtained with the Marquee® needle compared with the Achieve® needle. Early clinical experience demonstrates no significant difference in sample adequacy rates. Both needle types can be expected to provide adequate samples for pathologic assessment of liver tissue.

Small Bowel Crohn Disease at CT and MR Enterography: Imaging Atlas and Glossary of Terms.

Representatives from the Society of Abdominal Radiology Crohn's Disease-Focused Panel, the Society for Pediatric Radiology, the American Gastroenterological Association, and other international experts recently reported consensus recommendations for standardized nomenclature for the interpretation and reporting of CT enterography and MR enterography findings of small bowel Crohn disease. The consensus recommendations included CT enterography and MR enterography bowel wall findings that are associated with Crohn disease, findings that occur with penetrating Crohn disease, and changes that occur in the mesentery related to Crohn disease. Also included were recommended radiology report impression statements that summarize the findings of small bowel Crohn disease at CT enterography and MR enterography. This article, authored by the Society of Abdominal Radiology Crohn's Disease-Focused Panel, illustrates the imaging findings and recommended radiology report impression statements described in the consensus recommendations with examples of CT enterography and MR enterography images. Additional interpretation guidelines for reporting CT enterography and MR enterography examinations are also presented. The recommended standardized nomenclature can be used to generate radiology report dictations that will help guide medical and surgical management for patients with small bowel Crohn disease. Online supplemental material is available for this article. ©RSNA, 2020See discussion on this article by Heverhagen.

Computed tomography and magnetic resonance enterography protocols and techniques: survey of the Society of Abdominal Radiology Crohn's Disease Disease-Focused Panel.

PURPOSE: To survey Society of Abdominal Radiology Crohn's Disease (CD) Disease-Focused Panel (DFP) members to understand state-of-the-art CT/MR enterography (CTE/MRE) protocols and variability between institutions. METHODS: This study was determined by an institutional review board to be "exempt" research. The survey consisted of 70 questions about CTE/MRE patient preparation, administration of contrast materials, imaging techniques, and other protocol details. The survey was administered to DFP members using SurveyMonkey® (Surveymonkey.com). Descriptive statistical analyses were performed. RESULTS: Responses were received from 16 DFP institutions (3 non-USA, 2 pediatric); 15 (94%) were academic/university-based. 10 (63%) Institutions image most CD patients with MRE; 4 (25%) use CTE and MRE equally. Hypoperistaltic medication is given for MRE at 13 (81%) institutions versus only 2 (13%) institutions for CTE. Most institutions have a technologist or nurse monitor oral contrast material drinking (n = 12 for CTE, 75%; n = 11 for MRE, 69%). 2 (13%) institutions use only dual-energy capable scanners for CTE, while 9 (56%) use either a single-energy or dual-energy scanner based on availability. Axial CTE images are reconstructed at 2-3 mm thickness at 8 (50%) institutions, > 3 mm at 5 (31%), and < 2 mm at 3 (19%) institutions. 13 (81%) institutions perform MRE on either 1.5 or 3T scanners without preference. All institutions perform MRE multiphase postcontrast imaging (median = 4 phases), ranging from 20 to 600 s after contrast material injection. CONCLUSION: CTE and MRE protocol knowledge from DFP institutions can help radiology practices optimize/standardize protocols, potentially improving image quality and patient outcomes, permitting objective comparisons between examinations, and facilitating research.

Moving Radiology Workflow to the Electronic Health Record: Quantitative and Qualitative Experience From a Large Academic Medical Center.

RATIONALE AND OBJECTIVES: To objectively and subjectively evaluate a large, academic radiology department's transition to electronic health record (EHR) centered workflow. MATERIALS AND METHODS: Multiple metrics were compared from before and after the move to EHR-driven workflow. Examination ordering and reading priority data were obtained for 30 days both before and after the transition. Sixteen radiologists were observed opening a computed tomography (CT) examination, and time to open, mouse clicks, and keystrokes were recorded. Information available to the radiologist during interpretation was also compared. Additionally, a 12 question survey was sent out to the residents and faculty both before and after the transition. RESULTS: Implementation of an eight-level reading priority system increased worklist granularity and improved identification of more urgent studies to read. Radiologists opened CT studies in picture archiving and communications system-driven workflow in 52.4 ± 16.9 seconds using 9.5 ± 3.9 clicks and 6.3 ± 2.9 keystrokes, compared to 17.3 ± 9.5 seconds, 4.8 ± 1.5 clicks, and 0.1 ± 0.3 keystrokes in EHR-driven workflow (p < 0.001 for each measure). More information was available to the radiologist during examination interpretation, and 54.7% of radiologists rated the ease of use of the new system as good or very good (compared to 4.2% for the old system, p < 0.001). CONCLUSION: Transitioning to an EHR-driven workflow at a large academic medical center improved efficiency, was favorable to radiologists, and enhanced examination prioritization.

Imaging-guided percutaneous thrombin injection for the treatment of iatrogenic femoral artery pseudoaneurysms.

PURPOSE: To evaluate factors that may affect successful ultrasound-guided percutaneous thrombin injection of iatrogenic femoral artery pseudoaneurysms (PSA). MATERIALS AND METHODS: This was an IRB-approved, HIPAA-compliant retrospective study of 326 consecutive subjects (138 males, 188 females; mean age 68 years, range 18-95) who underwent thrombin injection for treatment of femoral PSA; follow-up ultrasound was available in 145 subjects. The number of PSA lobes and dimensions, pre-procedure laboratory values (international normalized ratio [INR], activated partial thromboplastin time [aPTT], platelet count), and concomitant anticoagulation therapy were recorded. RESULTS: Technical success was achieved in 98.2% (320/326) of subjects. Primary effectiveness (complete thrombosis at 24 h) was achieved in 74.5% (108/145). Twenty-five subjects underwent repeat thrombin injection, successful in 21 subjects, for a total effectiveness rate of 97.0% (129/133). No imaging factor was associated with technique failure, including number of lobes (p = 0.898), largest dimension (p = 0.344), or volume (p = 0.697). No statistically significant difference in pre-procedure INR, aPTT, or platelet count was found between subjects with CT and those with IT (p > 0.138). Anticoagulation therapy was associated with incomplete thrombosis (35.5% [38/107] for CT vs. 63.9% [23/26] for IT; p = 0.002). CONCLUSION: Imaging-guided percutaneous thrombin injection has high technical success and effectiveness rates for the treatment of iatrogenic femoral artery PSA. Anticoagulation therapy was the only factor associated with incomplete thrombosis.

Automated Early Identification of an Excessive Air-in-Oil X-ray Tube Artifact That Mimics Acute Cerebral Infarct.

PURPOSE: This study aimed to develop an automated, quantitative method to increase the likelihood of identifying and preventing such air-in-oil (AIO) artifact. METHODS: A 1-dimensional radial representation of the 2-dimensional noise power spectrum (NPS) was calculated from AIO artifact images and compared with artifact-free images. A quality control (QC) software program was modified to include measurements of NPS average frequency within the water section of daily phantom scans. Threshold values for each CT system were incorporated into daily QC. RESULTS: Noise power spectrum for AIO artifact images included a large low-frequency peak compared with artifact-free images; NPS average frequencies were 0.197 and 0.319 line pairs per millimeter for AIO artifact and artifact-free images, respectively. Automated QC successfully identified 3 AIO artifacts before detrimental clinical effect occurred. CONCLUSIONS: Serious clinical problems associated with AIO artifact can be detected and avoided by incorporating NPS average frequency measurements of daily phantom images into an automated QC program.