Fluid Distribution Patterns in Early-Stage Upper Extremity Lymphedema.

INTRODUCTION: Magnetic resonance imaging (MRI) stage 1 (early stage) upper extremity lymphedema is characterized by fluid infiltration in the subcutaneous tissues that does not exceed 50% of the extremity circumference at any level. The spatial fluid distribution in these cases has not been detailed and may be important to help determine the presence and location of compensatory lymphatic channels. The aim of this study is to determine whether there was a pattern of distribution of fluid infiltration in patients with early-stage lymphedema that could correspond to known lymphatic pathways in the upper extremity. METHODS: A retrospective review identified all patients with MRI stage 1 upper extremity lymphedema who were evaluated at a single lymphatic center. Using a standardized scoring system, a radiologist graded the severity of fluid infiltration at 18 anatomical locations. A cumulative spatial histogram was then created to map out regions where fluid accumulation occurred most and least frequently. RESULTS: Eleven patients with MRI stage 1 upper extremity lymphedema were identified between January 2017 and January 2022. The mean age was 58 years and the mean BMI was 30 m/kg2. One patient had primary lymphedema and the remaining 10 had secondary lymphedema. The forearm was affected in nine cases, and fluid infiltration was predominantly concentrated along the ulnar aspect, followed by the volar aspect, while the radial aspect was completely spared. Within the upper arm, fluid was primarily concentrated distally and posteriorly, and occasionally medially. CONCLUSIONS: In patients with early-stage lymphedema, fluid infiltration is concentrated along the ulnar forearm and the posterior distal upper arm, which aligns with the tricipital lymphatic pathway. There is also sparing of fluid accumulation along the radial forearm in these patients, suggesting a more robust lymphatic drainage along this region, possibly due to a connection to the lateral upper arm pathway.

MRI of Lymphedema.

Lymphedema is a devastating disease that has no cure. Management of lymphedema has evolved rapidly over the past two decades with the advent of surgeries that can ameliorate symptoms. MRI has played an increasingly important role in the diagnosis and evaluation of lymphedema, as it provides high spatial resolution of the distribution and severity of soft tissue edema, characterizes diseased lymphatic channels, and assesses secondary effects such as fat hypertrophy. Many different MR techniques have been developed for the evaluation of lymphedema, and the modality can be tailored to suit the needs of a lymphatic clinic. In this review article we provide an overview of lymphedema, current management options, and the current role of MRI in lymphedema diagnosis and management. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 5.

Rate of Incidental Edema in the Contralateral Arm of Patients with Unilateral Postsurgical Secondary Upper Extremity Lymphedema.

Background: Secondary upper extremity lymphedema occurs after an insult such as surgery. One theory suggests underlying lymphatic dysfunction predisposing certain patients into developing secondary lymphedema. We aim to determine the rate of incidental edema in the contralateral upper extremity of patients with secondary unilateral lymphedema. Methods and Results: MRI of the upper extremities were obtained in patients with lymphedema who were referred by a lymphedema clinic from 2017 to 2019. Axial short-tau inversion recovery MR images of the symptomatic and contralateral arms were retrospectively reviewed and edema severity was graded. Interobserver agreement was calculated. Indocyanine green (ICG) lymphography was compared against MRI stage in symptomatic and contralateral. Age, symptom duration, body mass index (BMI), and history of chemotherapy were compared between patients with and without contralateral limb lymphedema. ICG severity was compared against MRI stage. Seventy-eight patients were analyzed. The MRI stages of symptomatic versus contralateral arms were 1.7 ± 1.1 versus 0.1 ± 0.4 (p < 0.00001). Interobserver agreement was 0.86 (0.79-0.94). Of the patients with MRI Stage 1 or above in the symptomatic arm (n = 64), 55 (82.1%) patients demonstrated no abnormality in the contralateral arm. Nine patients (14.1%) demonstrated asymptomatic edema (MRI Stage 1). The mean ICG lymphography stage of symptomatic versus contralateral arms was 1.83 ± 0.96 versus 0.04 ± 0.25 (p < 0.00001). There was no difference in the age, symptom duration, BMI, or history of chemotherapy between patients with or without edema in the contralateral arm. Conclusion: Asymptomatic contralateral edema was detected in 14.1% of patients with unilateral secondary upper extremity lymphedema using MRI modality.

Predicting ipsilateral recurrence in women treated for ductal carcinoma in situ using machine learning and multivariable logistic regression models.

PURPOSE: To develop machine learning (ML) and multivariable regression models to predict ipsilateral breast event (IBE) risk after ductal carcinoma in situ (DCIS) treatment. METHODS: A retrospective investigation was conducted of patients diagnosed with DCIS from 2007 to 2014 who were followed for a minimum of five years after treatment. Data about each patient were extracted from the medical records. Two ML models (penalized logistic regression and random forest) and a multivariable logistic regression model were developed to evaluate recurrence-related variables. RESULTS: 650 women (mean age 56 years, range 27-87 years) underwent treatment for DCIS and were followed for at least five years after treatment (mean 8.0 years). 5.5% (n = 36) experienced an IBE. With multivariable analysis, the variables associated with higher IBE risk were younger age (adjusted odds ratio [aOR] 0.96, p = 0.02), dense breasts at mammography (aOR 3.02, p = 0.02), and < 5 years of endocrine therapy (aOR 4.48, p = 0.02). The multivariable regression model to predict IBE risk achieved an area under the receiver operating characteristic curve (AUC) of 0.75 (95% CI 0.67-0.84). The penalized logistic regression and random forest models achieved mean AUCs of 0.52 (95% CI 0.42-0.61) and 0.54 (95% CI 0.43-0.65), respectively. CONCLUSION: Variables associated with higher IBE risk after DCIS treatment include younger age, dense breasts, and <5 years of adjuvant endocrine therapy. The multivariable logistic regression model attained the highest AUC (0.75), suggesting that regression models have a critical role in risk prediction for patients with DCIS.

Enhancement Type at Contrast-enhanced Mammography and Association with Malignancy.

Background Despite the increasing use of contrast-enhanced mammography (CEM), there are limited data on the evaluation of findings on recombined images and the association with malignancy. Purpose To determine the rates of malignancy of enhancement findings on CEM images in the presence or absence of low-energy findings using the Breast Imaging Reporting and Data System (BI-RADS) lexicon developed for mammography and MRI. Materials and Methods All diagnostic CEM examinations performed at one academic institution between December 2015 and December 2019 had low-energy and recombined images retrospectively. Data were independently reviewed by three breast imaging radiologists with 5-25 years of experience using the BI-RADS mammography and MRI lexicon. Outcome was determined with pathologic analysis or 1-year imaging or clinical follow-up. The χ2 and Fisher exact tests were used for analysis. Results A total of 371 diagnostic CEM studies were performed in 371 women (mean age, 54 years ± 11[SD]). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value of enhancement on CEM images was 95% (104 of 109 [95% CI: 90, 98]), 67% (176 of 262 [95% CI: 61, 73]), 55% (104 of 190 [95% CI: 47, 62]), and 97% (176 of 181 [95% CI: 94, 99]), respectively. Among 190 CEM studies with enhancing findings, enhancing lesions were more likely to be malignant when associated with low-energy findings (26% vs 59%, P < .001). Among enhancement types, mass enhancement composed 71% (99 of 140) of all malignancies with PPV of 63% when associated with low-energy findings. Foci, non-mass enhancement, and mass enhancement without low-energy findings had PPV of 6%, 24%, and 38%, respectively. Neither background parenchymal enhancement nor density was associated with enhancement type (P = .19 and P = .28, respectively). Conclusion Mass enhancement on recombined images using CEM was most commonly associated with malignancy, especially when associated with low-energy findings. Enhancement types were more likely to be benign when not associated with low-energy findings; however, they should still be viewed with suspicion, given the high association with malignancy. © RSNA, 2022 Online supplemental material is available for this article.

Characterization of True and False Positive Findings on Contrast-Enhanced Mammography.

RATIONALE AND OBJECTIVES: The purpose of this paper is to characterize true and false positive findings on contrast-enhanced mammography (CEM) and correlate enhancement pattern and method of detection with pathology outcomes. MATERIALS AND METHODS: This was an IRB-approved retrospective review of diagnostic CEM performed from December 2015 through December 2019 for which biopsy was recommended. Background parenchymal enhancement, tissue density, finding features, pathologic/clinical outcomes, and method of detection were captured. CEM includes low-energy images (LE), similar to standard 2D mammography, and recombined images (RI) that show enhancement. 'MG-detected' findings were identified on mammography or LE. 'RI-detected' findings were identified due to enhancement on RI. The positive predictive value (PPV2) was calculated on a per-case and a per-finding level. Comparisons were performed using Pearson chi-square and Fisher exact tests. RESULTS: One hundred sixty CEM cases with 220 findings were evaluated with a case PPV2 of 58.1%. 32.3% (71/220) of lesions were RI-detected.  The PPV2 of RI-detected enhancement was 40.8% with subanalysis revealing PPV2 of 22.2%, 32%, and 51.4% for foci, NME, and masses, respectively. The PPV2 of MG-detected enhancement was 73.5% with subanalysis revealing PPV2 of 50%, 54.1%, and 83.8% for foci, NME, and masses, respectively. There were 100 false positives findings, 42 of which were RI-detected. CONCLUSION: PPV2 of diagnostic CEM is within the range of other diagnostic breast imaging exams. However false positives remain a challenge, especially for RI-detected findings. Additional efforts to improve specificity of RI-detected findings are worthwhile.

Contralateral breast cancer after curative-intent treatment for ductal carcinoma in situ: Rate and associated clinicopathological and imaging risk factors.

PURPOSE: Patients who have ductal carcinoma in situ (DCIS) are undergoing bilateral mastectomy at increasing rates. One of the reasons is to minimize contralateral breast cancer (CBC) risk. The purpose of this study is to determine the rate of and risk factors associated with CBC in women treated for DCIS. METHODS: A retrospective study was performed of women with DCIS at surgery from 2007 to 2014 who had at least five-year follow-up. Patient attributes, imaging findings, histopathology results, and surgical and long-term outcomes were collected. Features associated with a CBC were assessed with multivariable logistic regression models. RESULTS: 613 women (mean 56 years, range 30-87) with DCIS underwent breast-conserving surgery (BCS) (n = 426), unilateral mastectomy (n = 101), or bilateral mastectomy (n = 86), with mean follow-up of 7.9 years. Of the 527 women who had BCS or unilateral mastectomy, 7.4% (n = 39) developed a CBC (DCIS in 12 and invasive cancer in 27). 4.1% (5/122) of women treated with adjuvant endocrine therapy developed a CBC, compared to 8.4% (34/405) who were not treated (p = .11). Features associated with CBC risk were younger age at menarche (adjusted odds ratio [aOR] of 0.76, p = .03) and low nuclear grade of DCIS (aOR of 5.43 for grade 1 versus 3, p = .01). CONCLUSION: In women treated for DCIS, the overall rate of CBC was low at 7.4%. Younger age at menarche and low nuclear grade of DCIS had significant associations with higher CBC risk.

Use of non-contrast MR in diagnosing secondary lymphedema of the upper extremities.

PURPOSE: The purpose of the study is to determine if a combination of dermal thickening and subcutaneous fluid honeycombing on non-contrast MRI, termed the dermal rim sign (DRS), can be diagnostically analogous to dermal backflow seen on lymphoscintigraphy in patients with secondary upper extremity lymphedema. MATERIALS AND METHODS: Upper extremity MRI and lymphoscintigraphy were performed on patients referred to a multidisciplinary lymphedema clinic for suspicion of secondary lymphedema. Sensitivity, specificity, and positive and negative predictive values of DRS on MRI in detecting dermal backflow on lymphoscintigraphy and the correlation between DRS, Indocyanine Green (ICG) lymphography, bioimpedence L-Dex® ratio and MRI Lymphedema Staging were calculated. Weighted interobserver agreements on the presence and location of DRS on MRI were calculated. RESULTS: Of the 45 patients in the study, 91.1% (41/45) of patients had history of breast cancer. The average age was 58.4 ± 10.5 years, with a mean symptom duration of 4.7 ± 4.4 years. The mean BMI was 30.5 ± 7.0 kg/m2. Interobserver agreement on the presence and the extent of DRS on MRI was 0.93 [95% confidence-interval: 0.80-1]. DRS was present in 97% (32/33) of patients who demonstrated dermal backflow on lymphoscintigraphy. Sensitivity, specificity, PPV, and NPV of DRS were 96.6% [81.7%-99.9%], and 75.0% [47.6%-92.7%], 87.5% [74.9%-94.3%], and 92.3% [63.1%-98.8%]. DRS was associated with severity on ICG lymphography and bioimpedance (both p < 0.001). CONCLUSIONS: DRS on non-contrast MRI is highly predictive of dermal backflow and correlates with clinical measures of lymphedema severity. DRS may be used as an independent diagnostic biomarker to identify patients who would benefit from dedicated exams.

Assessing Risk of Breast Cancer: A Review of Risk Prediction Models.

Accurate and individualized breast cancer risk assessment can be used to guide personalized screening and prevention recommendations. Existing risk prediction models use genetic and nongenetic risk factors to provide an estimate of a woman's breast cancer risk and/or the likelihood that she has a BRCA1 or BRCA2 mutation. Each model is best suited for specific clinical scenarios and may have limited applicability in certain types of patients. For example, the Breast Cancer Risk Assessment Tool, which identifies women who would benefit from chemoprevention, is readily accessible and user-friendly but cannot be used in women under 35 years of age or those with prior breast cancer or lobular carcinoma in situ. Emerging research on deep learning-based artificial intelligence (AI) models suggests that mammographic images contain risk indicators that could be used to strengthen existing risk prediction models. This article reviews breast cancer risk factors, describes the appropriate use, strengths, and limitations of each risk prediction model, and discusses the emerging role of AI for risk assessment.

Breast Cancer-Related Lymphedema: Magnetic Resonance Imaging Evidence of Sparing Centered Along the Cephalic Vein.

BACKGROUND: A distinct pattern of edema distribution is seen in breast cancer-related lymphedema. The area of edema sparing has not been characterized in relation to anatomy. Specifically, alternate lymphatic pathways are known to travel adjacent to the cephalic vein. Our study aims to define the location of edema sparing in the arm relative to the cephalic vein. METHODS: A retrospective review of patients who underwent magnetic resonance imaging (MRI) between March 2017 and September 2018 was performed. Variables including patient demographics, arm volumes, and MRI data were extracted. MRIs were reviewed to define the amount of sparing, or angle of sparing, and the deviation between the center of sparing and the cephalic vein, or angle of deviation. RESULTS: A total of 34 consecutive patients were included in the analysis. Five patients demonstrated circumferential edema (no sparing) and 29 patients demonstrated areas of edema sparing. Advanced age (69.7 vs. 57.6 years) and greater excess arm volume (40.4 vs. 20.8%) correlated with having circumferential edema without sparing (p = 0.003). In 29 patients with areas of edema sparing, the upper arm demonstrated the greatest angle of sparing (183.2 degrees) and the narrowest in the forearm (99.9 degrees; p = 0.0032). The mean angle of deviation to the cephalic vein measured 3.2, -0.1, and -5.2 degrees at the upper arm, elbow, and forearm, respectively. CONCLUSION: Our study found that the area of edema sparing, when present, is centered around the cephalic vein. This may be explained by the presence of the Mascagni-Sappey (M-S) pathway as it is located alongside the cephalic vein. Our findings represent a key springboard for additional research to better elucidate any trends between the presence of the M-S pathway, areas of sparing, and severity of lymphedema.

Noncalcified Ductal Carcinoma In Situ (DCIS): Rate and Predictors of Upgrade to Invasive Carcinoma.

RATIONALE AND OBJECTIVES: To determine the upgrade rate of noncalcified ductal carcinoma in situ (DCIS) and features that are associated with risk of upgrade to invasive disease at surgery. MATERIALS AND METHODS: A retrospective review was conducted of consecutive women who were diagnosed with noncalcified DCIS from January 2007 to December 2016. Patient demographics, imaging findings, biopsy pathology results, and surgical outcomes were reviewed. The unpaired t test, chi-square test, and Fisher's exact test were used to compare features between the cases of DCIS that did and did not upgrade to invasive carcinoma at surgery. RESULTS: Over a 10-year period, 78 women (mean age 62 years, range 30-88 years) were diagnosed with noncalcified DCIS. Two-thirds (67.9%, 53/78) of cases were detected on screening mammography, and 15.4% (12/78) of diagnoses were made after presentation with an area of palpable concern. The most common mammographic presentations of noncalcified DCIS were mass (51.3%, 40/78) and asymmetry (30.8%, 24/78). Seventeen cases (21.8%, 17/78) were upgraded to invasive ductal carcinoma (IDC) at surgery. Features associated with upgrade risk included older patient age (68.1 versus 60.3 years, OR 1.08, p < 0.01) and family history of breast cancer in a first-degree relative (41.2% [7/17] versus 16.4% [10/61], OR 3.57, p = 0.03). CONCLUSION: In our study cohort, the upgrade rate of noncalcified DCIS to IDC at surgery is 21.8%. Upgrade risk is associated with older patient age and family history of breast cancer in a first-degree relative.

Impact of digital breast tomosynthesis (DBT) on finding types leading to true-positive and false-positive examinations.

PURPOSE: To investigate the frequencies of finding types with combined digital breast tomosynthesis (DBT) and digital mammography (DM) leading to true-positive (TP) and false-positive (FP) examinations. MATERIALS AND METHODS: Consecutive screening mammograms at an academic medical center from March 2008 to February 2011 (DM group) and from January 2013 to December 2017 (DBT/DM group) were retrospectively reviewed. Multivariable logistic regression models were used to compare the proportions of mammographic finding types leading to TP and FP examinations between the two groups. RESULTS: The DM group had 554 TP and 7278 FP examinations, and the DBT/DM group had 1271 TP and 14,544 FP examinations. The finding type of calcifications led to a lower proportion of TP examinations in the DBT/DM than DM group (34.3% versus 47.7%, p < 0.001) but also a lower proportion of FP examinations (18.7% versus 21.7%, p < 0.001). Mass led to a higher proportion of TP examinations in the DBT/DM than DM group (5.7% versus 1.3%, p < 0.001) but also a higher proportion of FP examinations (4.6% versus 0.3%, p < 0.001). Asymmetry led to a higher proportion of TP examinations in the DBT/DM than DM group (58.3% versus 50.4%, p = 0.03) and a lower proportion of FP examinations (75.9% versus 77.6%, p < 0.001). Architectural distortion led a similar proportion of TP examinations in the DBT/DM and DM groups (1.7% versus 0.7%, p = 0.12) but a higher proportion of FP examinations (0.8% versus 0.4%, p = 0.007). CONCLUSIONS: Mammographic findings leading to TP and FP examinations have shifted with the addition of DBT to DM.

Contrast-enhanced Mammography: A Guide to Setting Up a New Clinical Program.

Contrast-enhanced mammography (CEM) is gaining rapid traction following the U.S. Food and Drug Administration approval for diagnostic indications. Contrast-enhanced mammography is an alternative form of mammography that uses a dual-energy technique for image acquisition after the intravenous administration of iodinated contrast material. The resulting exam includes a dual set of images, one that appears similar to a routine 2D mammogram and one that highlights areas of contrast uptake. Studies have shown improved sensitivity compared to mammography and similar performance to contrast-enhanced breast MRI. As radiology groups incorporate CEM into clinical practice they must first select the indications for which CEM will be used. Many practices initially use CEM as an MRI alternative or in cases recommended for biopsy. Practices should then define the CEM clinical workflow and patient selection to include ordering, scheduling, contrast safety screening, and managing imaging on the day of the exam. The main equipment requirements for performing CEM include CEM-capable mammography equipment, a power injector for contrast administration, and imaging-viewing capability. The main staffing requirements include personnel to place the intravenous line, perform the CEM exam, and interpret the CEM. To safely and appropriately perform CEM, staff must be trained in their respective roles and to manage potential contrast-related events. Lastly, informing referring colleagues and patients of CEM through marketing campaigns is helpful for successful implementation.

Ductal carcinoma in situ on digital mammography versus digital breast tomosynthesis: rates and predictors of pathologic upgrade.

OBJECTIVES: To compare upgrade rates of ductal carcinoma in situ (DCIS) on digital mammography (DM) versus digital breast tomosynthesis (DBT) and identify patient, imaging, and pathological features associated with upgrade risk. METHODS: A retrospective review was performed of 318 women (mean 59 years, range 37-89) with screening-detected DCIS from 2007 to 2011 (DM group) and from 2013 to 2016 (DBT group). Comparisons made between DM and DBT groups using the unpaired t test and chi-square test include detection rates of DCIS, upgrade rates to invasive cancer, and pathological features of DCIS and upgraded cases. Patient, imaging, and pathological features associated with upgrade were also determined. P values < 0.05 were considered significant. RESULTS: There was no significant difference in detection rates of DCIS between DM and DBT groups (0.9 versus 1.0 per 1000 examinations, p = 0.45). Upgrade rates of DCIS to invasive cancer in DM and DBT groups were similar (17.3% versus 16.8%, p = 0.90), despite significant differences in pathological features of DCIS between DM and DBT groups (including nuclear grade, comedonecrosis, and progesterone receptor status [p ≤ 0.01]). Among upgraded cases, a higher proportion were high-grade invasive cancers with DBT (36.7% versus 9.5%, p = 0.03). In both groups, ultrasound-guided (versus stereotactic) biopsy was associated with higher upgrade risk (p ≤ 0.03). CONCLUSIONS: There was no significant difference in detection rates or upgrade rates of DCIS on DM versus DBT; however, upgraded cases were more likely to be high grade with DBT, suggesting possible differences in tumor biology between cancers with DM and DBT. In both DM and DBT groups, biopsy modality was associated with upgrade risk. KEY POINTS: • Detection rates and upgrade rates of ductal carcinoma in situ (DCIS) on digital mammography (DM) versus digital breast tomosynthesis (DBT) are similar. • A higher proportion of upgraded cases were high-grade invasive cancers with DBT than DM, suggesting possible differences in tumor biology between cancers that are detected with DM and DBT. • With both DM and DBT, ultrasound-guided biopsy (versus stereotactic biopsy) was associated with a higher risk of upgrade.

MRI staging of upper extremity secondary lymphedema: correlation with clinical measurements.

OBJECTIVES: Staging of upper extremity lymphedema is needed to guide surgical management, but is not standardized due to lack of accessible, quantitative, or precise measures. Here, we established an MRI-based staging system for lymphedema and validate it against existing clinical measures. METHODS: Bilateral upper extremity MRI and lymphoscintigraphy were performed on 45 patients with unilateral secondary lymphedema, due to surgical intervention, who were referred to our multidisciplinary lymphedema clinic between March 2017 and October 2018. MRI short-tau inversion recovery (STIR) images were retrospectively reviewed. A grading system was established based on the cross-sectional circumferential extent of subcutaneous fluid infiltration at three locations, labeled MRI stage 0-3, and was compared to L-Dex®, ICG lymphography, volume, lymphedema quality of life (LYMQOL), International Society of Lymphology (ISL) stage, and lymphoscintigraphy. Linear weighted Cohen's kappa was calculated to compare MRI staging by two readers. RESULTS: STIR images on MRI revealed a predictable pattern of fluid infiltration centered on the elbow and extending along the posterior aspect of the upper arm and the ulnar side of the forearm. Patients with higher MRI stage were more likely to be in ISL stage 2 (p = 0.002) or to demonstrate dermal backflow on lymphoscintigraphy (p = 0.0002). No correlation was found between MRI stages and LYMQOL. Higher MRI stage correlated with abnormal ICG lymphography pattern (rs = 0.63, p < 0.0001), larger % difference in limb volume (rs = 0.68, p < 0.0001), and higher L-Dex® ratio (rs = 0.84, p < 0.0001). Cohen's kappa was 0.92 (95% CI, 0.85-1.00). CONCLUSION: An MRI staging system for upper extremity lymphedema offers an improved non-invasive precision marker for lymphedema for therapeutic planning. KEY POINTS: • Diagnosis and staging of patients with secondary upper extremity lymphedema may be performed with non-contrast MRI, which is non-invasive and more readily accessible compared to lymphoscintigraphy and evaluation by lymphedema specialists. • MRI-based staging of secondary upper extremity lymphedema is highly reproducible and could be used for long-term follow-up of patients. • In patients with borderline clinical measurements, MRI can be used to identify patients with early-stage lymphedema.

Comparison of Contrast-Enhanced Mammography With Conventional Digital Mammography in Breast Cancer Screening: A Pilot Study.

PURPOSE: To perform a pilot evaluation of contrast-enhanced mammography (CEM) for screening to determine whether it can improve accuracy and reader confidence in diagnosis. METHODS AND MATERIALS: This institutional review board-approved reader study was comprised of 64 de-identified CEM cases acquired from December 1, 2014, to June 7, 2016, including 48 negative, 5 biopsy-proven benign, and 11 biopsy-proven malignancies. Negative cases were followed for at least 2 years without evidence of cancer. Ten breast imagers of varying experience first rated the low-energy (LE) mammogram and then the CEM examination using BI-RADS categories and a 5-point Likert scale for confidence in diagnosis. RESULTS: There were 635 out a total possible 640 complete reader interpretations included in this analysis. The remaining five incomplete interpretations were excluded. Median sensitivity and specificity improved with the addition of CEM (sensitivity: 0.86 [95% confidence interval {CI}: 0.74-0.95] versus 1 [95% CI: 0.83-1.00], specificity: 0.85 [95% CI: 0.64-0.94] versus 0.88 [95% CI: 0.80-0.92]). Individual receiver operating characteristic curves showed significant improvement with CEM (mean area under the curve increase = 0.056 [95% CI: 0.015-0.097], P = .002). The addition of CEM significantly improved average confidence in 5 of 10 readers when compared with LE (P < .0001) and improved pooled confidence across all tissue density categories, except the almost entirely fatty category. There was a trend toward improved confidence with increasing tissue density with CEM. Degree of background parenchymal enhancement did not affect readers' level of improvement in confidence when interpreting CEM. SUMMARY: CEM improved reader performance and confidence compared with viewing only LE, suggesting a role for CEM in breast cancer screening for which larger trials are warranted.

Causes and Rates of 30-day Readmissions after Percutaneous Transhepatic Biliary Drainage Procedure.

Purpose To investigate rates and causes of 30-day readmission for patients who undergo percutaneous transhepatic biliary drainage (PTBD) procedures. Materials and Methods In this retrospective study, PTBD procedures performed at a tertiary care institution (June 2008 to May 2013) were reviewed. For each patient, the first 30-day readmission was used to determine cause of readmission. Two interventional radiologists independently categorized causes for readmission as planned or unplanned, and unplanned causes as related to or unrelated to interventional radiology. Interventional radiology-related readmissions were categorized as potentially preventable or unpreventable. Factors associated with higher odds for 30-day readmission were identified with univariable and multivariable analysis. Results There were 266 procedures in 266 patients (mean age, 67 years; interquartile range, 57-76 years; 53.4% men). The cause of obstruction was malignant in 50.0% of patients (133 of 266). There were 122 of 266 patients (45.9%) readmitted within 30 days. Of these readmissions, 44 of 122 (36.1%) were planned and 78 of 122 (63.9%) were unplanned. A majority of unplanned readmissions (57 of 78; 73%) were related to interventional radiology. Of unplanned interventional radiology-related readmissions, 16% (nine of 57) were related to periprocedural complications and 51% (29 of 57) were considered preventable. At multivariable analysis, Medicaid insurance (odds ratio, 3.68; 95% confidence interval: 1.52, 9.99; P = .009) and bilateral PTBDs (odds ratio, 5.81; 95% confidence interval: 1.79, 18.90; P = .003) were associated with 30-day readmission. Conclusion Thirty-day readmissions after primary biliary drainage are common and a majority of unplanned readmissions are drain-related. Nearly half of unplanned interventional radiology-related readmissions are potentially preventable. © RSNA, 2018 See also the editorial by Nikolic in this issue.