American Journal of Roentgenology

Twenty-five years ago, oligometastatic disease was proposed as an intermediary clinical state of cancer with unique implications for therapies that may impact cancer evolution and patient outcome. Identification of limited metastases that are potentially amenable to targeted therapies fundamentally depends on the sensitivity of diagnostic tools, including new-generation imaging methods. For men with biochemical recurrence after definitive therapy of the primary prostate cancer, PET/CT using either the FDA-approved radiolabeled amino acid analogue ¹⁸F-fluciclovine or investigational radiolabeled agents targeting prostate-specific membrane antigen (PSMA) enables identification of early metastases at lower serum PSA levels than was previously feasible using conventional imaging. Evidence supports PSMA PET/CT as the most sensitive imaging modality available for identifying disease sites in oligometastatic prostate cancer. PSMA PET/CT will likely become the modality of choice after regulatory approval and will drive the development of trials of emerging metastasis-directed therapies such as stereotactic ablative body radiation and radioguided surgery. Indeed, numerous ongoing or planned clinical trials are studying advances in management of oligometastatic prostate cancer based on this heightened diagnostic capacity. In this rapidly evolving clinical environment, radiologists and nuclear medicine physicians will play major roles in facilitating clinical decision making and management of patients with oligometastatic prostate cancer.

BI-RADS is a communication and data tracking system that has evolved since its inception as a brief mammography lexicon and reporting guide into a robust structured reporting platform and comprehensive quality assurance tool for mammography, ultrasound, and MRI. Consistent and appropriate use of the BI-RADS lexicon terminology and assessment categories effectively communicates findings, estimates the risk of malignancy, and provides management recommendations to patients and referring clinicians. The impact of BI-RADS currently extends internationally through six language translations. A condensed version has been proposed to facilitate a phased implementation of BI-RADS in resource-constrained regions. The primary advance of the 5th edition of BI-RADS is harmonization of the lexicon terms across mammography, ultrasound, and MRI. Harmonization has also been achieved across these modalities for the reporting structure, assessment categories, management recommendations, and data tracking system. Areas for improvement relate to certain common findings that lack lexicon descriptors and a need for further clarification of proper use of category 3. BI-RADS is anticipated to continue to evolve for application to a range of emerging breast imaging modalities.

OBJECTIVE. The purpose of this study was to conduct a meta-analysis to assess the safety and efficacy of empiric embolization compared with targeted embolization in the treatment of acute upper gastrointestinal bleeding (UGIB).

MATERIALS AND METHODS. We searched the PubMed and Cochrane Library databases for studies performed without language restrictions from January 2000 to November 2019. Only clinical studies with a sample size of five or more were included. Clinical success, rebleeding and complication rates, survival rates, bleeding cause, embolic materials, and vessels embolized were recorded. Empiric embolization and targeted embolization (i.e., embolization performed based on angiographic evidence of ongoing bleeding) were compared when possible. Meta-analysis was performed.

RESULTS. Among 13 included studies (12 retrospective and 1 prospective), a total of 357 of 725 patients (49.2%) underwent empiric embolization for UGIB. The clinical success rate of empiric embolization was 74.7% (95% CI, 63.1–86.3%) among the 13 studies, and the survival rate was 80.9% (95% CI, 73.8–88.0%) for 10 studies. On the basis of comparative studies, no statistically significant difference was observed between empiric and targeted embolization in terms of rebleeding rate in 11 studies (36.5% vs 29.6%; odds ratio [OR], 1.13; 95% CI, 0.77–1.65; p = .53), mortality in eight studies (23.3% vs 18.0%; OR, 1.44; 95% CI, 0.89–2.33; p = .14), and need for surgery to control rebleeding in four studies (17.8% vs 13.4%; OR, 1.34; 95% CI, 0.58–3.07; p = .49). The pooled embolization-specific complications were 1.9% (empiric) and 2.4% (targeted).

CONCLUSION. According to all available published evidence, empiric embolization assessed with endoscopic or preprocedural imaging findings (or both) appears to be as effective as targeted embolization in preventing rebleeding and mortality in patients with angiographically negative acute UGIB. Because of its favorable safety profile, empiric embolization should be considered for patients in this clinical scenario.

OBJECTIVE. One central question pertaining to mammography quality relates to discerning the optimal recall rate to maximize cancer detection while minimizing unnecessary downstream diagnostic imaging and breast biopsies. We examined the trade-offs for higher recall rates in terms of biopsy recommendations and cancer detection in a single large health care organization.

MATERIALS AND METHODS. We included 2D analog, 2D digital, and 3D digital (tomosynthesis) screening mammography examinations among women 40–79 years old performed between January 1, 2005, and December 31, 2017, with cancer follow-up through 2018. There were 36, 67, and 38 radiologists who read at least 1000 2D analog examinations, 2D digital examinations, and 3D tomosynthesis examinations, respectively, who were included in these analyses. Using logistic regression with marginal standardization, we estimated radiologist-specific mean recall (abnormal interpretations/1000 mammograms), biopsy recommendation, cancer detection (screening-detected in situ and invasive cancers/1000 mammograms), and minimally invasive cancer detection rates while adjusting for differences in patient characteristics.

RESULTS. Among 1,060,655 screening mammograms, the mean recall rate was 10.7%, the cancer detection rate was 4.0/1000 mammograms, and the biopsy recommendation rate was 1.60%. Recall rates between 7% and 9% appeared to maximize cancer detection while minimizing unnecessary biopsies.

CONCLUSION. The results of this investigation are in contrast to those of a recent study suggesting appropriateness of higher recall rates. The “sweet spot” for optimal cancer detection appears to be in the recall rate range of 7–9% for both 2D digital mammography and 3D tomosynthesis. Too many women are being called back for diagnostic imaging, and new benchmarks could be set to reduce this burden.

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BACKGROUND. The incidence of ductal carcinoma in situ (DCIS) has steadily increased, as have concerns regarding overtreatment. Active surveillance is a novel treatment strategy that avoids surgical excision, but identifying patients with occult invasive disease who should be excluded from active surveillance is challenging. Radiologists are not typically expected to predict the upstaging of DCIS to invasive disease, though they might be trained to perform this task.

OBJECTIVE. The purpose of this study was to determine whether a mixed-methods two-stage observer study can improve radiologists' ability to predict upstaging of DCIS to invasive disease on mammography.

METHODS. All cases of DCIS calcifications that underwent stereotactic biopsy between 2010 and 2015 were identified. Two cohorts were randomly generated, each containing 150 cases (120 pure DCIS cases and 30 DCIS cases upstaged to invasive disease at surgery). Nine breast radiologists reviewed the mammograms in the first cohort in a blinded fashion and scored the probability of upstaging to invasive disease. The radiologists then reviewed the cases and results collectively in a focus group to develop consensus criteria that could improve their ability to predict upstaging. The radiologists reviewed the mammograms from the second cohort in a blinded fashion and again scored the probability of upstaging. Statistical analysis compared the performances between rounds 1 and 2.

RESULTS. The mean AUC for reader performance in predicting upstaging in round 1 was 0.623 (range, 0.514–0.684). In the focus group, radiologists agreed that upstaging was better predicted when an associated mass, asymmetry, or architectural distortion was present; when densely packed calcifications extended over a larger area; and when the most suspicious features were focused on rather than the most common features. Additionally, radiologists agreed that BI-RADS descriptors do not adequately characterize risk of invasion, and that microinvasive disease and smaller areas of DCIS will have poor prediction estimates. Reader performance significantly improved in round 2 (mean AUC, 0.765; range, 0.617–0.852; p = .045).

CONCLUSION. A mixed-methods two-stage observer study identified factors that helped radiologists significantly improve their ability to predict upstaging of DCIS to invasive disease.

CLINICAL IMPACT. Breast radiologists can be trained to better predict upstaging of DCIS to invasive disease, which may facilitate discussions with patients and referring providers.

OBJECTIVE. The purpose of this article is to evaluate whether digital mammography (DM) is associated with persistent increased detection of ductal carcinoma in situ (DCIS) or has altered the upgrade rate of DCIS to invasive cancer.

MATERIALS AND METHODS. An institutional review board–approved retrospective search identified DCIS diagnosed in women with mammographic calcifications between 2001 and 2014. Ipsilateral cancer within 2 years, masses, papillary DCIS, and patients with outside imaging were excluded, yielding 484 cases. Medical records were reviewed for mammographic calcifications, technique, and pathologic diagnosis. Mammograms were interpreted by radiologists certified by the Mammography Quality Standards Act. The institution transitioned from film-screen mammography (FSM) to exclusive DM by 2010. Statistical analyses were performed using chi-square test.

RESULTS. Of 484 DCIS cases, 158 (33%) were detected by FSM and 326 (67%) were detected by DM. The detection rate was higher with DM than FSM (1.4 and 0.7 per 1000, respectively; p < .001). The detection rate of high-grade DCIS doubled with DM compared with FSM (0.8 and 0.4 per 1000, respectively; p < .001). The prevalent peak of DM-detected DCIS was 2.7 per 1000 in 2008. Incident DM detection remained double FSM (1.4 vs 0.7 per 1000). Similar proportions of high-grade versus low- to intermediate-grade DCIS were detected with both modalities. There was no significant difference in the upgrade rate of DCIS to invasive cancer between DM (10%; 34/326) and FSM (10%; 15/158) (p = .74). High-grade DCIS led to 71% (35/49) of the upgrades to invasive cancer.

CONCLUSION. DM was associated with a significant doubling in DCIS and high-grade DCIS detection, which persisted after prevalent peak. The majority of upgrades to invasive cancer arose from high-grade DCIS. DM was not associated with decreased upgrade to invasive cancer.

BACKGROUND. Low-dose CT (LDCT) lung cancer screening (LCS) has been shown to decrease mortality in persons with a significant smoking history. However, adherence in real-world LCS programs is significantly lower than in randomized controlled trials.

OBJECTIVE. The purpose of this article is to assess real-world LDCT LCS performance and factors predictive of adherence to LCS recommendations.

METHODS. We retrospectively identified all persons who underwent at least two LCS examinations from 2014 to 2019. Patient demographics, smoking history and behavior changes, Lung-RADS category, PPV, NPV, and adherence to screening recommendations were recorded. Predictors of adherence were assessed via univariate comparisons and multivariate logistic regression.

RESULTS. A total of 260 persons returned for follow-up LDCT (57.7% had two, 34.2% had three, 7.7% had four, and 0.4% had five LDCT examinations). A total of 43 of 260 (16.5%) had positive (Lung-RADS category 3 or above) scans, of which 27 of 260 persons (10.3%) were graded as Lung-RADS category 3, eight of 260 (3.1%) were category 4A, six of 260 (2.3%) were category 4B, and two of 260 (0.8%) were category 4X. Cancer was diagnosed in four of the 260 (three with lung cancer and one with metastatic melanoma). A total of 143 of 260 (55.0%) persons were current smokers at baseline and 121 of 260 (46.5%) were current smokers at the last round of LCS. LCS had sensitivity of 100.0%, specificity of 84.8%, PPV of 9.3%, and NPV of 100%. Overall adherence was 43.0% but increased progressively with higher Lung-RADS category (Lung-RADS 1: 33.2%; Lung-RADS 2: 46.3%; Lung-RADS 3: 53.8%; Lung-RADS 4A: 77.8%; Lung-RADS 4B: 83.3%; Lung-RADS 4X: 100%; p < .001). was also higher in former versus current smokers (50.0% vs 36.2%; p < .001). Being a former smoker and having a nodule that is Lung-RADS category 3 or greater were the only significant independent predictors of adherence.

CONCLUSION. Our real-world LCS program showed very high sensitivity and NPV, but moderate specificity and very low PPV. Adherence to LCS recommendations increased with former versus current smokers and in those with positive (Lung-RADS categories 3, 4A, 4B, or 4X) LCS examinations. Adherence was less than 50.0% in current smokers and persons with negative (Lung-RADS categories 1 or 2) LCS examinations.

CLINICAL IMPACT. Our results offer a road map for targeted performance improvement by focusing on LCS subjects less likely to remain in the program, such as persons with negative LCS examinations and persons who continue to smoke, potentially improving LCS cost effectiveness and maximizing its societal benefits.

OBJECTIVE. The objective of this article is to discuss the anatomy, embryonic origin, normal variants, and various attachments of the ligament of Treitz. We also describe the pathologic processes that develop along the ligament of Treitz and the role of cross-sectional imaging in identifying these conditions.

CONCLUSION. The ligament of Treitz, also known as the suspensory ligament of the duodenum, is an important anatomic landmark in the abdomen. It is essential that radiologists understand the anatomic attachments, normal variants, and various pathologic conditions involving the ligament of Treitz as well as the role of cross-sectional imaging in the assessment of these conditions.

OBJECTIVE. The purpose of this study is to determine the impact of LI-RADS ancillary features on MRI and to ascertain whether the number of ancillary features can be reduced without compromising LI-RADS accuracy.

MATERIALS AND METHODS. A total of 222 liver observations in 81 consecutive patients were identified on MRI between August 2013 and December 2018. The presence or absence of major and ancillary features was used to determine the LI-RADS category for LR-1 to LR-5 observations. Final diagnosis was established on the basis of pathologic findings or one of several composite clinical reference standards. Diagnostic accuracy was compared with and without ancillary features by use of the z test of proportions. Decision tree analysis and machine learning–based feature pruning were used to identify noncontributory ancillary features for LI-RADS categorization. Interobserver agreement with and without ancillary features was measured using the Krippendorff alpha coefficient, and comparisons were made using bootstrapping. A p < .05 was considered statistically significant.

RESULTS. Application of ancillary features resulted in a change in the LI-RADS category of seven hepatocellular carcinomas (HCCs), with the category of six of seven (86%) HCCs upgraded; 51 benign observations also had a change in LI-RADS category, with the category of 33 (65%) of these observations downgraded. When ancillary features were applied, the percentage of HCCs in each LI-RADS category did not differ significantly compared with major features alone (p = .06–.49). Decision tree analysis and the machine learning model identified five ancillary features as noncontributory: corona enhancement, nodule-in-nodule, mosaic architecture, blood products in mass, and fat in a mass, more than in adjacent liver. Interobserver agreement was high with and without application of ancillary features; however, it was significantly higher without ancillary features (p < .001).

CONCLUSION. Although ancillary features are an important component of LI-RADS, their impact may be small. Several ancillary features likely can be removed from LI-RADS without compromising diagnostic performance.

Active surveillance for low-to-intermediate risk prostate cancer is a conservative management approach that aims to avoid or delay active treatment until there is evidence of disease progression. In recent years, multiparametric MRI (mpMRI) has been increasingly used in active surveillance and has shown great promise in patient selection and monitoring. This has been corroborated by publication of the Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation (PRECISE) recommendations, which define the ideal reporting standards for mpMRI during active surveillance. The PRECISE recommendations include a system that assigns a score from 1 to 5 (the PRECISE score) for the assessment of radiologic change on serial mpMRI scans. PRECISE scores are defined as follows: a score of 3 indicates radiologic stability, a score of 1 or 2 denotes radiologic regression, and a score of 4 or 5 indicates radiologic progression. In the present study, we discuss current and future trends in the use of mpMRI during active surveillance and illustrate the natural history of prostate cancer on serial scans according to the PRECISE recommendations. We highlight how the ability to classify radiologic change on mpMRI with use of the PRECISE recommendations helps clinical decision making.

OBJECTIVE. The purpose of this study was to report on the practice patterns and challenges of performing and interpreting prostate MRI.

SUBJECTS AND METHODS. An electronic survey regarding prostate MRI practice patterns and challenges was sent to members of the Society of Abdominal Radiology.

RESULTS. The response rate was 15% (212/1446). Most (65%) of the respondents were academic abdominal radiologists with 1–5 (52%), 6–10 (20%), 11–20 (15%), and more than 20 (5%) years of experience in reporting prostate MRI. The numbers of prostate MRI examinations reported per week were 0–5 (43%), 6–10 (38%), 11–20 (12%), 21–30 (5%), and more than 30 (2%). Imaging was performed at 3 T (58%), 1.5 T (20%), or either (21%), and most examinations (83%) were performed without an endorectal coil. Highest b values ranged from 800 to 5000 s/mm²; 1400 s/mm² (26%) and 1500 s/mm² (30%) were the most common. Most respondents (79%) acquired dynamic contrast-enhanced images with temporal resolution of less than 10 seconds. Most (71%) of the prostate MRI studies were used for fusion biopsy. PI-RADS version 2 was used by 92% of the respondents and template reporting by 80%. Challenges to performing and interpreting prostate MRI were scored on a 1–5 Likert scale (1, easy; 2, somewhat easy; 3, neutral; 4, somewhat difficult; 5, very difficult). The median scores were 2 or 3 for patient preparatory factors. Image acquisition and reporting factors were scored 1–2, except for performing spectroscopy or using an endorectal coil, both of which scored 4. Acquiring patient history scored 2 and quality factors scored 3.

CONCLUSION. Most radiologists perform prostate MRI at 3 T without an endorectal coil and interpret the images using PI-RADS version 2. Challenges include obtaining quality images, acquiring feedback, and variability in the interpretation of PI-RADS scores.

OBJECTIVE. The purpose of this study was to determine if contrast enhancement is necessary for MRI surveillance of clinical T1a (cT1a) solid renal masses.

MATERIALS AND METHODS. With institutional review board approval, 36 patients who underwent two or more contrast-enhanced (CE) MRI examinations (median, four examinations; range, two to 10 examinations) for surveillance of 39 cT1a solid renal masses between 2009 and 2019 (median time between scans, 2 years; range, 1–7 years) were evaluated. Two radiologists independently measured renal mass size and assessed tumor stage in two sessions for baseline and follow-up examinations using T1-weighted nephrographic phase CE-MRI and unenhanced single-shot T2-weighted MRI in mixed order with a 4-week washout period. Comparisons were performed using the Wilcoxon sign-rank test and Pearson correlation. Bland-Altman and intraclass correlation determined interobserver agreement.

RESULTS. Mean size ± SD of renal masses on CE-MRI and T2-weighted MRI were 18 ± 5 mm (range, 9–37 mm) and 18 ± 5 mm (range, 9–37 mm) for radiologist 1 and 19 ± 7 mm (range, 10–39 mm) and 19 ± 6 mm (range, 10–39 mm) for radiologist 2 with near perfect correlation (for radiologist 1, β = 0.9897; for radiologist 2, β = 0.9317; p < .001). Interob-server agreement for measurements comparing radiologist 1 and radiologist 2 on CEMRI and T2-weighted MRI and intraobserver agreement for measurements on CE-MRI and T2-weighted MRI were excellent. Mean growth rate of renal masses measured on CE-MRI and T2-weighted MRI were 2 ± 2 mm (range, −5 to 8 mm) and 2 ± 3 mm (range, −3 to 8 mm) for radiologist 1 and 3 ± 5 mm (range, −1 to 18 mm) and 3 ± 6 mm (range, −1 to 24 mm) for radiologist 2 with high correlation (for radiologist 1, β = 0.8313 [p < .001]; for radiologist 2, β = 0.848 [p = .002]). At baseline, all tumors were subjectively cT1a on CE-MRI and T2-weighted MRI (p > .99, intraclass correlation coefficient [ICC] = 1). During follow-up, one mass progressed to T3 on CE-MRI and T2-weighted MRI for radiologist 1 and radiologist 2 (p > .99, ICC = 1).

CONCLUSION. In this study, size measurements on unenhanced T2-weighted MRI had near perfect correlation to measurements using CE-MRI in cT1a solid renal masses undergoing surveillance, with high agreement between and within observers. Clinical staging did not differ comparing T2-weighted MRI and CE-MRI, with near perfect agreement. Contrast enhancement is not necessary for follow-up size measurements in cT1a solid renal masses with MRI.

OBJECTIVE. The purpose of this article was to evaluate MRI features of uterine leiomyomas that predict volumetric response after uterine artery embolization (UAE).

MATERIALS AND METHODS. This retrospective study included 75 patients with 212 uterine leiomyomas who were successfully treated between August 2013 and December 2018. To predict uterine volumetric response, age, number of lesions, and baseline uterine volume were assessed. To predict leiomyoma volumetric response, a multivariate regression analysis was performed to evaluate six predictive factors: location, baseline leiomyoma volume, signal intensity on T1-weighted and T2-weighted MRI, heterogeneity of signal intensity on T2-weighted MRI, and vascularity on subtraction imaging (SI). A five-variable predictive ROC model was developed to evaluate the diagnostic accuracy of the signal intensity ratio on T2-weighted MRI, enhancement ratio, heterogeneity ratio on T2-weighted MRI, location, and baseline leiomyoma volume in predicting at least 40% leiomyoma volumetric response.

RESULTS. Age, number of leiomyomas, and baseline uterine volume were not predictive of uterine volumetric response. A submucosal location was the best predictive factor of leiomyoma volumetric response, and it showed 32.2% more leiomyoma volumetric response compared with a nonsubmucosal location (p < .001). Hyperintensity on T2-weighted MRI was the second best predictive factor of leiomyoma volumetric response, and it showed 16.9% more volumetric response compared with hypointense leiomyomas (p = .013). A small baseline leiomyoma volume (< 58 cm³) was associated with 10.2% more leiomyoma volumetric response compared with larger leiomyomas (p = .01). Leiomyomas that were hyperintense on SI showed 7.9% more leiomyoma volumetric response compared with those that were hypointense (p = .014). The five-variable ROC model showed high diagnostic accuracy with an AUC of 0.85, sensitivity of 82%, and specificity of 71%.

CONCLUSION. A submucosal location, hyperintensity on T2-weighted MRI, small baseline leiomyoma volume (< 58 cm³), and hyperintense leiomyoma on subtraction imaging are the main independent favorable predictors of leiomyoma volumetric response after UAE. An accurate predictive ROC model was developed that may help in selecting patients suitable for UAE. Quantitative assessment of heterogeneity on T2-weighted MRI showed promising results as a predictor of volumetric response, and further research in this area using texture analysis and radiomics is suggested.

OBJECTIVE. The purpose of this study was to assess feasibility and rate of patients returning to the hospital when a same-day discharge protocol is used for patients undergoing transradial uterine artery embolization (UAE) for symptomatic fibroids.

MATERIALS AND METHODS. A total of 374 patients who underwent transradial UAE with a same-day discharge protocol between April 2013 and June 2019, with documented follow-up, were included in this single-health-system retrospective study. Angiographic images and procedural reports were reviewed for technical success (defined as bilateral embolization). Electronic medical records were reviewed for patient and fibroid characteristics, adverse events, clinical success (defined as documented improvement in symptoms or patient satisfaction), and unplanned clinic visits, emergency department visits, and readmissions within 30 days of UAE. Univariate and multivariate analyses were used to identify risk factors for unplanned visits.

RESULTS. Eight (2.1%) patients required conversion to inpatient stay (mean length of stay, 1.4 days; range, 1–3 days). The median postprocedure observation time was 3.7 hours (range, 1.1–12.5 hours). Technical success was achieved in 94.7% of patients, with 2.4% requiring crossover to the femoral artery for access. Clinical success was achieved in 86.0% of patients, with 6-month reductions in uterus and dominant leiomyoma volume of 30.4% and 42.9%, respectively. Rates of unplanned clinic visits, emergency department visits, and readmissions were 3.2%, 5.1%, and 0.5%, respectively. Patients with submucosal fibroids or pain as an indication for UAE were significantly more likely to have unplanned visits.

CONCLUSION. Transradial UAE for symptomatic fibroids can be performed using a same-day discharge protocol with low rates of patients returning to the hospital. Submucosal location and pain as an indication for UAE were predictors of early return.

OBJECTIVE. Coupled ECG-electromagnetic (EM) guidance shows promise for use in placement of peripherally inserted central catheters (PICCs) when compared with the classic blind technique. However, ECG-EM guidance has not been appropriately compared with the reference standard of fluoroscopy (FX) guidance. Here, we aimed to compare ECG-EM guidance with FX guidance with regard to the final tip position of PICCs.

SUBJECTS AND METHODS. A total of 120 patients (age range, 19–94 years) referred for PICC placement were randomized to the ECG-EM or FX group. All interventions were performed by PICC team members who had the same standardized training and experience. Final tip position was assessed using chest radiography and was classified as optimal, suboptimal, or inadequate requiring repositioning on the basis of the distance from the PICC tip to the cavoatrial junction (CAJ). Statistical analyses were performed using the Mann-Whitney U test for final catheter tip position (mean distance from CAJ) and Fisher and chi-square tests for proportions.

RESULTS. PICCs were successfully inserted in 118 patients (53 men and 65 women). Catheter tip positions were optimal or suboptimal in 100% of the FX group and 77.2% of the ECG-EM group. Furthermore, precision of placement was significantly better (p = .004) in the FX group (mean distance from the PICC tip to the CAJ = 0.83 cm) than in the ECGEM group (mean distance from the PICC tip to the CAJ = 1.37 cm). Thirteen (22.8%) of the PICCs placed using ECG-EM guidance, all of which were inserted from the left side, were qualified as inadequate requiring repositioning and required another intervention.

CONCLUSION. Our results revealed significant differences in final tip position between the ECG-EM and FX guidance techniques and indicate that ECG-EM guidance cannot appropriately replace FX guidance among unselected patients. However, ECGEM guidance could be considered as an acceptable technique for patients in whom the PICC could be inserted from the right side.

TRIAL REGISTRATION. ClinicalTrials.gov NCT03652727

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BACKGROUND. Obesity is a worldwide problem that impacts patient health as well as the morbidity associated with surgical procedures. Thus, patients with morbid obesity may not be suitable candidates for curative surgery. For this patient population, thermal ablation may be an effective alternative to nephrectomy.

OBJECTIVE. The purpose of this study was to determine the feasibility, oncologic outcomes, and survival of patients with morbid obesity and renal cell carcinoma treated with thermal ablation.

MATERIALS AND METHODS. A retrospective analysis was performed of 107 patients treated with CT-guided renal ablation for clinical T1 renal cell carcinoma between February 2005 and December 2017. Patients were stratified into two cohorts on body mass index of ≥ 40 kg/m² (morbidly obese) and body mass index (weight in kilograms divided by the square of height in meters) of ≥ 40 (morbidly obese) and 18.5–24.9 (normal weight). Anesthetic and radiation dosages, procedure time, residual disease, and local recurrence, and adverse events were analyzed between the two groups. Kaplan-Meier statistics were used to evaluate cancer-related outcomes for each group.

RESULTS. Thirty-four patients were morbidly obese, and 73 patients had normal weight. Morbid obesity was associated with longer procedural duration (p = .001), sedative doses (p = .002) and radiation exposure (p = .001) than normal weight. Hematomas were more prevalent in patients with morbid obesity than in those of normal weight (p = .01), but treatment efficacy and local recurrences were comparable with those for normal-weight individuals (p = .81 and p = .12, respectively). Cancer-related outcomes were equivalent between the two groups based on 5 years of imaging observation data.

CONCLUSION. CT-guided thermal ablation remains technically feasible, well-tolerated, and effective in patients with morbid obesity and renal cell carcinoma, with the caveat of increased risk of perinephric hematoma, anesthesia dose, and radiation exposure.

CLINICAL IMPACT. CT-guided thermal ablation can be considered a safe and effective treatment for renal cell carcinoma in patients with morbid obesity.

OBJECTIVE. Diagnostic accuracy of core needle biopsy (CNB) for adipocytic tumors can be low because of sampling error from these often large, heterogeneous lesions. The purpose of this study was to evaluate the diagnostic accuracy of image-guided CNB for various adipocytic tumors in comparison with excisional pathology.

MATERIALS AND METHODS. Adipocytic tumors (n = 77) of all adult patients undergoing image-guided CNB and subsequent surgical excision of an adipocytic tumor at a tertiary referral center between 2005 and 2019 were studied. To determine concordance, we compared pathologic diagnoses based on CNB to the reference standard of pathologic diagnoses after surgical excision. Tumors were divided into three categories (benign lipomatous tumors [lipoma, lipoma variants, hibernomas], atypical lipomatous tumors [ALTs] or well-differentiated liposarcomas [WDLs], and higher grade liposarcomas [myxoid, dedifferentiated, pleomorphic]), and diagnostic accuracy was calculated for each category.

RESULTS. In 73 of 77 adipocytic tumors (95%), diagnosis at CNB and diagnosis after excision were concordant. Accuracy of diagnosis was poorer for ALTs and WDLs than for the other two categories, and the difference was statistically significant (p < .002). For the 29 benign lipomatous tumors and the 27 higher-grade liposarcomas, diagnoses at CNB and after excision were concordant in all cases (100%). Seventeen of the 21 tumors (81%) diagnosed as ALTs or WDLs at CNB had a concordant diagnosis after excision; four of the 21 were upgraded (dedifferentiated liposarcoma, n = 3; myxoid liposarcoma, n = 1).

CONCLUSION. CNB provides high diagnostic accuracy for adipocytic tumors, particularly for benign lipomatous tumors and higher grade liposarcomas. However, though still high at 81%, diagnostic accuracy of CNB is not as high for tumors diagnosed as ALTs or WDLs. Awareness of this limitation is important when determining management, particularly of cases of ALT or WDL for which surgery is not planned.

OBJECTIVE. The purpose of this study was to evaluate the diagnostic utility of dual-layer CT (DLCT) for evaluating wrist injuries and to compare it with MRI.

MATERIALS AND METHODS. The cases of 62 patients with suspected wrist fractures who underwent imaging with both DLCT and MRI from January 2018 through February 2019 were retrospectively reviewed. By means of a calcium suppression algorithm, virtual noncalcium (VNCa) image reconstruction was performed, and the images were reviewed by two readers to identify fractures, bone contusions, and nontraumatic lesions in the radius, ulna, and carpal bones. Sensitivity, specificity, PPV, and NPV were calculated and compared between standard CT and VNCa images with a combination of standard CT and MRI as the reference standard.

RESULTS. Use of DLCT with VNCa reconstruction increased the sensitivity of diagnosis of fractures in the radius and carpal bones over that of standard CT alone; occult fractures were detected that were not seen with standard CT. The sensitivity and specificity for detecting radius fracture were 98.1% and 93.8% for DLCT and 96.3% and 93.8% for standard CT. For detecting carpal bone fracture, sensitivity and specificity were 100% and 98.9% for DLCT and 93.8% and 100% for standard CT. VNCa reconstruction also had good diagnostic accuracy with regard to diagnosing nonfracture bone contusions in carpal bones. The accuracy was comparable to that of MRI with sensitivity of 92.9% and specificity of 94.5%. Interreader agreement in interpreting VNCa images was generally good to excellent.

CONCLUSION. DLCT with VNCa reconstruction is a promising tool for identifying occult wrist fractures and nonfracture contusion injuries in patients with wrist trauma.

OBJECTIVE. The purpose of this study was to assess the utility of radiography in diagnosing osteonecrosis of the femoral head with pathologic examination as the reference standard.

MATERIALS AND METHODS. Radiography and pathology reports of 253 consecutive femoral head resections were reviewed. A subset of 128 cases in which the diagnosis of osteonecrosis was made or suggested radiographically or pathologically were reviewed to evaluate for factors that might influence correlation. A total of 23 patients in this subset had also undergone MRI, and those reports and images were reviewed.

RESULTS. There was 93.9% agreement between radiography and pathologic examination overall (κ = 0.67). When grade 3 osteoarthritis was present, 95.0% agreement was found, but because of the large number of patients with severe osteoarthritis, the kappa value decreased to 0.51. In the subset of cases in which osteonecrosis was diagnosed or suspected, radiologic-pathologic correlation decreased as osteoarthritis grade increased, and the diagnostic uncertainty for both evaluation methods increased. One patient without osteoarthritis had osteonecrosis diagnosed in both hips at radiography and MRI, but osteonecrosis was absent at pathologic examination.

CONCLUSION. Radiography depicts osteonecrosis in most patients who have osteonecrosis and subsequently undergo femoral head resection. False-positive and false-negative radiographic findings occur, however. Diagnosis is most difficult in patients with advanced osteoarthritis or subchondral fractures. The number of patients who underwent MRI was not sufficient for evaluation of the accuracy of MRI.

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BACKGROUND. CT attenuation thresholds that accurately distinguish enostoses from untreated osteoblastic metastases have been published. In the Mayo Clinic practices, these thresholds have been applied more broadly to distinguish benign sclerotic bone lesions other than enostoses from osteoblastic metastases.

OBJECTIVE. The purpose of this article is to determine if CT attenuation thresholds allow the distinguishing of benign sclerotic bone lesions from osteoblastic metastases in patients undergoing bone biopsy.

METHODS. A retrospective search was conducted to identify sclerotic lesions described on CT between October 7, 1998, and July 15, 2018, that underwent subsequent biopsy. Two musculoskeletal radiologists recorded lesions' maximum and mean attenuation. Using previously published attenuation thresholds, sensitivity and specificity for differentiating benign sclerotic lesions from osteoblastic metastases were calculated. ROC curve analysis was performed to determine if more appropriate attenuation thresholds exist. Intraclass correlation coefficients (ICCs) were computed.

RESULTS. A total of 280 patients met inclusion criteria. Of those, 162 had malignant biopsy results and 118 had benign biopsy results. Of the 162 malignant lesions, 81 had received prior treatment. Maximum and mean attenuation were not significantly different between benign and malignant lesions for either reader (all p > .05). For reader 1, to distinguish benign from malignant lesions, a maximum attenuation threshold of more than 1060 HU resulted in sensitivity of 23.7%, specificity of 87.0%, and accuracy of 60.6%. A mean attenuation threshold of greater than 885 HU resulted in sensitivity of 19.5%, specificity of 90.7%, and accuracy 60.7%. ROC curve analysis showed AUCs for mean and maximum attenuation thresholds of 51.8% and 54.6%, respectively. Subgroup analyses of benign versus malignant and treated versus untreated lesions had similar results. Similar findings were obtained for reader 2. The two readers' ICC was 0.946 for maximum attenuation and 0.918 for mean attenuation.

CONCLUSION. Published attenuation thresholds for distinguishing enostoses from osteoblastic metastases had slightly decreased specificity and markedly decreased sensitivity when applied to the differentiation of benign sclerotic lesions from osteoblastic metastases in our sample of biopsy-proven lesions. ROC analysis showed no high-performing attenuation threshold alternative.

CLINICAL IMPACT. Published CT attenuation thresholds intended for distinguishing enostoses from osteoblastic metastases should not be used more broadly. More accurate alternative thresholds could not be derived.

Myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD) is a distinct CNS inflammatory disease with symptoms and imaging findings that overlap other neuroinflammatory disorders. We highlight the imaging characteristics of MOGAD and contrast them with neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). Intracranial features that suggest MOGAD include childhood acute disseminated encephalomyelitis pattern with diffuse signal abnormality in the cortical gray matter, subcortical white matter, deep white matter, and deep gray matter on T2-weighted and FLAIR images; few bilateral T2-hyperintense fluffy and poorly demarcated lesions; pontine or thalamic involvement (or both); and cerebellar peduncle lesions in children. Intraorbitally, one sees edematous, enlarged, tortuous optic nerve or nerves; bilateral long-segment T2 hyperintensity of anterior segments of the optic nerve; sparing of the optic chiasm and retrochiasmatic pathways; and perioptic nerve sheath and surrounding orbital fat enhancement. Spinal involvement is seen as longitudinally extensive transverse myelitis with a sagittal T2-hyperintense intramedullary spinal line, the axial “H” spinal cord sign (central cord gray matter T2 hyperintensity), and conus medullaris involvement. Early accurate diagnosis of MOGAD is important because prognosis and treatment differ from those for NMOSD and MS.

OBJECTIVE. We hypothesized that intravitreal silicone oil would show attenuation similar to that of fat on dual-energy CT 190-keV virtual monoenergetic images (VMIs) with high frequency and that this appearance would enable confident determination of the presence or absence of intravitreal silicone oil. The purpose of the present study was to test our hypothesis in a blinded multireader study of selected patients with and without intravitreal silicone oil as well as in an unblinded ROI-based assessment.

MATERIALS AND METHODS. In this retrospective study of 50 dual-energy CT examinations of the head that included 100 globes (64 that were normal, 19 that exhibited hyperattenuating mimics, and 17 that contained silicone oil), three neuroradiologists independently assessed anonymized 190-keV VMIs for intravitreal attenuation similar to that of fat. Interobserver agreement was calculated. The mean attenuation value on weighted-average images and 190-keV VMIs was recorded.

RESULTS. The three readers identified intravitreal attenuation values similar to that of fat in 100% of globes that contained silicone oil and 0% of globes that did not contain silicone oil (100% sensitivity, specificity, PPV, and accuracy) with 100% agreement. The mean attenuation value of silicone oil on 190-keV VMIs was −55 HU, which was significantly less than the mean attenuation on 190-keV VMIs of normal globes and hyperattenuating mimics (p < .001 for both).

CONCLUSION. Intravitreal silicone oil shows attenuation of −60 to −49 HU on 190-keV VMIs. With the use of these images only, three neuroradiologists identified intravitreal silicone oil with 100% accuracy and perfect agreement.

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Among 2820 inpatients with coronavirus disease (COVID-19), 59 (2.1%) underwent brain MRI. Of them, six (10.2%) had MRI findings suspicious for COVID-19–related disseminated leukoencephalopathy (CRDL), which is characterized by extensive confluent or multifocal white matter lesions (with characteristics and locations atypical for other causes), microhemorrhages, diffusion restriction, and enhancement. CRDL is an uncommon but important differential consideration in patients with neurologic manifestations of COVID-19.

OBJECTIVE. The purpose of this article is to provide an illustrative review of nonsyndromic congenital causes of sensorineural hearing loss (SNHL) in children.

CONCLUSION. Early recognition and treatment are essential in maximizing developmental outcomes in children with congenital SNHL. Because imaging plays an integral role in identifying underlying causes of SNHL, it is imperative that radiologists be able to recognize, describe, and appropriately categorize the spectrum of congenital inner ear malformations in children.

OBJECTIVE. Subpial hemorrhages, typically seen in neonates, are rare but can harm the adjacent brain parenchyma. The purpose of this review is to summarize the anatomy and pathophysiology of subpial hemorrhage and highlight its characteristic neuro-imaging pattern.

CONCLUSION. The distinctive neuroimaging pattern of subpial hemorrhage is best appreciated on brain MRI, which shows the morphology over the cortex and injury to adjacent cortex and subcortical white matter. These findings do not occur in subarachnoid and subdural hemorrhages. Recognizing the pattern of subpial hemorrhages should guide prognostic precision, prognostication, and counseling.

OBJECTIVE. Percutaneous imaging-guided core needle biopsies (CNBs) for cancer diagnosis in pediatric patients are gaining interest because of their availability, lower rate of complications, and high diagnostic power compared with traditional surgical biopsies. Nevertheless, their precise role in the diagnostic algorithm of pediatric oncology is still unknown. The purpose of this study was to report our accumulated 16-year experience with CNB; discuss the availability, safety, and diagnostic accuracy of the procedure and the adequacy of ancillary testing; and compare our findings with the available literature.

MATERIALS AND METHODS. Pediatric ultrasound-guided CNBs performed in our hospital between November 2003 and December 2019 were retrospectively studied. Data collection included demographics, clinical and procedural parameters, complications, and final diagnosis.

RESULTS. A total of 597 biopsies were performed in 531 patients (132 performed in known oncologic patients and 465 performed to establish diagnosis). The median time between the biopsy request and the procedure was 1 day. Of 432 biopsies performed in patients with malignancies, 12 (2.8%) had false-negative results. In 165 cases of benign pathologic findings, all had true-negative results. Ancillary testing was adequate in all malignant cases. Overall sensitivity, specificity, and accuracy rates were 97.2%, 100%, and 98.0%, respectively. Five biopsies (0.8%) resulted in complications, including one major bleed and one track seeding.

CONCLUSION. Our experience shows that ultrasound-guided CNB for suspected malignancy in pediatric patients has a high safety profile, availability, and accuracy rate compared with surgical biopsy. Our fast-track strategy enables early initiation of designated therapy and has the potential to become the procedure of choice.

OBJECTIVE. The purpose of our study was to prospectively evaluate the technical feasibility of the free-breathing fast T2-weighted MultiVane XD sequence (sequence with non-Cartesian k-space filling using radial rectangular blades) at 3-T MRI for large airway assessment in pediatric patients.

SUBJECTS AND METHODS. Forty consecutive pediatric patients (23 boys and 17 girls; age range, 5–15 years) referred for MRI examination for indications not related to neck, chest, or large airway disorders were enrolled in this prospective research study. All children underwent MRI in three planes using a free-breathing fast T2-weighted MultiVane XD sequence at 3-T MRI. The MR images were assessed by two pediatric radiologists independently for visualization of the large airways at six levels. The quality of the MR images was assessed and graded. Interobserver agreement between two radiologists was assessed using the kappa test, McNemar test, and intraclass correlation coefficients.

RESULTS. High-quality MR images of the large airways were obtained in at least one plane in 38 MRI examinations (95.0%) by reviewer 1 and 37 MRI examinations (92.5%) by reviewer 2. Best-quality MR images with the least artifacts were seen in the sagittal plane followed by the coronal plane and the axial plane. The kappa test of agreement showed almost-perfect agreement between the two radiologists for MR image quality in the sagittal (κ = 1), coronal (κ = 0.96), and axial (κ = 0.81) planes. The McNemar test and intraclass correlation coefficients revealed similar results.

CONCLUSION. The free-breathing fast T2-weighted MultiVane XD sequence at 3-T MRI is a technically feasible and promising new MRI technique for evaluating the large airways of pediatric patients in daily clinical practice.

OBJECTIVE. The purpose of this study was to compare radiology trainees' perceptions of the culture regarding speaking up about patient safety and unprofessional behavior in the clinical environment and to assess the likelihood that they will speak up in the presence of a medical hierarchy.

MATERIALS AND METHODS. The study included radiology trainees from nine hospitals who attended a communication workshop. Trainees completed questionnaires assessing their perceptions of the support provided by their clinical environment regarding speaking up about patient safety and unprofessional behavior. We also queried their likelihood of speaking up within a team hierarchy about an error presented in a hypothetical clinical vignette.

RESULTS. Of 61 participants, 58 (95%) completed questionnaires. Of these 58 participants, 84% felt encouraged by colleagues to speak up about safety concerns, and 57% felt encouraged to speak up about unprofessional behavior (p < .001). Moreover, 17% and 34% thought speaking up about safety concerns and unprofessional behavior, respectively, was difficult (p < .02). Trainees were less likely to agree that speaking up about unprofessional behavior (compared with speaking up about safety concerns) resulted in meaningful change (66% vs 95%; p < .001). In a vignette describing a sterile technique error, respondents were less likely to speak up to an attending radiologist (48%) versus a nurse, intern, or resident (79%, 84%, and 81%, respectively; p < .001). Significant predictors of the likelihood of trainees speaking up to an attending radiologist included perceived potential for patient harm as a result of the error (odds ratio [OR], 6.7; p < .001), perceptions of safety culture in the clinical environment (OR, 5.0; p = .03), and race or ethnicity (OR, 3.1; p = .03).

CONCLUSION. Radiology trainees indicate gaps in workplace cultures regarding speaking up, particularly concerning unprofessional behavior and team hierarchy.

Please see the Editorial Comment by Anil K. Dasyam discussing this article.

BACKGROUND. Coronavirus disease (COVID-19) is known to be associated with a distinct form of coagulopathy.

OBJECTIVE. The purpose of this study was to describe the imaging manifestations of COVID-19–associated coagulopathy across anatomic sites and modalities in hospitalized patients and to identify clinical variables associated with positive imaging findings.

METHODS. We conducted a retrospective review of consecutive adult patients with COVID-19 admitted to our hospital over a 3-week period. Data on patient demographics, hematologic values, cross-sectional imaging examinations, and clinical outcomes (death and intubation) were collected. Imaging was reviewed for manifestations of coagulopathy. Multivariable logistic regression analyses were performed to assess associations of patient demographics, hematologic markers, and outcomes with the need for imaging and imaging manifestations of coagulopathy.

RESULTS. Of 308 hospitalized patients with COVID-19, 142 (46%) underwent 332 cross-sectional imaging examinations. Of these, 37 (26%) had imaging results positive for coagulopathy. The most common imaging manifestations of coagulopathy were pulmonary embolus (n = 21) on contrast-enhanced CT or CTA, thrombus in the upper- or lower-extremity veins (n = 13) on Doppler ultrasound, end-organ infarction in the bowel (n = 4) and kidney (n = 4) on contrast-enhanced CT, and thrombus or parenchymal infarction in the brain (n = 2) on contrast-enhanced CTA or MRI with MRA. Among patients with imaging results positive for coagulopathy, eight (22%) had multisite involvement. Thrombi were multifocal in four of five patients with positive upper-extremity and three of eight patients with positive lower-extremity examination results and involved superficial veins, deep veins, or both. In multivariable analysis, intubation (p < .001) and prolonged prothrombin time (p = .04) were significantly associated with undergoing imaging. No patient variable was significantly associated with imaging results positive for coagulopathy (p > .05).

CONCLUSION. Imaging commonly shows manifestations of coagulopathy in hospitalized patients with COVID-19. Over one-fifth of patients with such manifestations show multisite involvement. Clinical variables poorly predict which patients have positive imaging results, indicating a complementary role of imaging in detecting COVID-19–associated coagulopathy.

CLINICAL IMPACT. In patients with COVID-19 with suspected systemic coagulopathy, pulmonary CTA, extremity Doppler ultrasound, contrast-enhanced abdominal CT, and contrast-enhanced brain MRI and MRA may all be appropriate in the absence of imaging contraindications.

OBJECTIVE. The purpose of this article is to provide radiologists with a guide to the fundamental principles of oncology clinical trials. The review summarizes the evolution and structure of modern clinical trials with an emphasis on the relevance of clinical trials in the field of oncologic imaging.

CONCLUSION. Understanding the structure and clinical relevance of modern clinical trials is beneficial for radiologists in the field of oncologic imaging.

OBJECTIVE. The purpose of this article is to familiarize radiologists with the evidence-based imaging guidelines of major oncologic societies and organizations and to discuss approaches to effective implementation of the most recent guidelines in daily radiology practice.

CONCLUSION. In an era of precision oncology, radiologists in practice and radiologists in training are key stakeholders in multidisciplinary care, and their awareness and understanding of society guidelines is critically important.

OBJECTIVE. The purpose of our study was to assess the feasibility of 2D shear wave ultrasound elastography to quantitatively measure changes of rigor mortis.

SUBJECTS AND METHODS. Muscle stiffness of two live pigs and nine sacrificed pigs was measured in kilopascals using ultrasound elastography. The nine sacrificed pigs were divided into three groups of three pigs each and placed in one of three environments at 90°F (32°C), 70°F (21°C), or 34°F (1°C). Ultrasound elastography of five muscles was performed at 1- to 2-hour intervals for up to 50 hours postmortem. For each pig and muscle location, the time to start, peak intensity, duration of peak, and time to decline of rigor mortis were identified from the graphs of muscle stiffness values over time. These outcome variables were then compared across ambient temperature, body weight, and age groups using the Wilcoxon rank sum test.

RESULTS. Postmortem measurements show a rise, peak, and decline of muscle stiffness after death. Rigor mortis was highly significantly affected by ambient temperature (p < .001), was significantly affected by body weight (p = .04), and was not significantly affected by animal age or muscle location (facial vs truncal vs limb) (p > .50). Peak intensity of rigor mortis developed more quickly but attained lower levels of muscle stiffness at 90°F (80–100 kPa) compared with 70°F and 34°F (280–300 kPa) (p < .001). The duration of peak rigor mortis and the time to decline of rigor mortis were significantly longer for the lower temperatures (p < .001).

CONCLUSION. Two-dimensional shear wave ultrasound elastography can quantifi-ably measure the trajectory of rigor mortis in an animal model. This new approach may have direct implications for human forensic investigations.