Increasing utilization of contrast-enhanced ultrasound during abdominal biopsies: impact of an educational training program.

RATIONAL AND OBJECTIVES: To increase utilization of contrast-enhanced ultrasound (CEUS) during ultrasound-guided targeted liver biopsies. MATERIAL AND METHODS: Two educational training interventions performed to increase use of CEUS. First, 14 radiologists (fellowship-trained in Abdominal Imaging) given didactic teaching and case presentations on the use of CEUS. Second, hands-on teaching on how to use CEUS provided to the same group. To determine the efficacy of these two interventions, radiologists completed anonymous surveys to determine the level of understanding and acceptability of using CEUS before and 6 months after CEUS training. In addition, the percentage of CEUS assisted liver biopsies was compared for the 6 months before and 6 months after the training. RESULTS: Pre-training survey completed by 11 radiologists and post-training survey completed by 9 radiologists. Before training, 11% survey responders use CEUS routinely, whereas 89% never or rarely used it. After training, 54% of respondents were new users and 100% reported they planned to use CEUS in the future. Unfamiliarity (71%) was the main reason for not using it. After training, 25% reported lack of comfort with using CEUS as the main reason for not using CEUS. During six months before training, CEUS was administered in 6% (10/172) of targeted liver biopsies. Six months after training, CEUS was used nearly twice as often (10%, 16/160, P = 0.09, 1-sided Boschloo test). The number of radiologists using CEUS increased to 57% (8/14) after training compared to 20% (3/14, P = 0.03, 1-sided Boschloo) before training. CONCLUSION: Educational training intervention increases use of CEUS during ultrasound-guided targeted liver biopsies.

Deep learning for classification of thyroid nodules on ultrasound: validation on an independent dataset.

OBJECTIVES: The purpose is to apply a previously validated deep learning algorithm to a new thyroid nodule ultrasound image dataset and compare its performances with radiologists. METHODS: Prior study presented an algorithm which is able to detect thyroid nodules and then make malignancy classifications with two ultrasound images. A multi-task deep convolutional neural network was trained from 1278 nodules and originally tested with 99 separate nodules. The results were comparable with that of radiologists. The algorithm was further tested with 378 nodules imaged with ultrasound machines from different manufacturers and product types than the training cases. Four experienced radiologists were requested to evaluate the nodules for comparison with deep learning. RESULTS: The Area Under Curve (AUC) of the deep learning algorithm and four radiologists were calculated with parametric, binormal estimation. For the deep learning algorithm, the AUC was 0.69 (95% CI: 0.64-0.75). The AUC of radiologists were 0.63 (95% CI: 0.59-0.67), 0.66 (95% CI:0.61-0.71), 0.65 (95% CI: 0.60-0.70), and 0.63 (95%CI: 0.58-0.67). CONCLUSION: In the new testing dataset, the deep learning algorithm achieved similar performances with all four radiologists. The relative performance difference between the algorithm and the radiologists is not significantly affected by the difference of ultrasound scanner.

Comparison of clinical efficacy, subjective user experience, and safety for two different core biopsy needles, the Achieve® and Marquee®.

PURPOSE: To compare clinical efficacy, subjective radiologist preference, and complication rates for two different core biopsy needles, the Achieve® and Marquee®. METHODS: Retrospective review included consecutive patients who underwent 18 gauge non-targeted core liver biopsy, 30 with Achieve® (Merit Medical) and 30 with Marquee® (BD Bard) Pathologist (blinded to needle type) reviewed specimen total length, maximum width, and portal triad count. Sixteen radiologists subjectively rated (1 to 5(best)) each needle for cocking, firing, recoil, chamber exposure, handling, and overall. A medical records search of all (targeted and non-targeted) core liver biopsies 1/1/17-9/30/2020 compared rates of major (requiring transfusion and/or embolization) and minor (self-limited bleeding) hemorrhagic complications. Comparison between needle types was performed using t-test. RESULTS: For Achieve® and Marquee® needles, the respective mean (SD) for total length(mm) was 29.7(7.0) and 31.9(4.6), p = 0.1; max width(mm) was 0.78(0.1) and 0.85(0.1), p < 0.01; and number of portal triads was 15.3(5.3) and 17.3(5.3), p = 0.2. Radiologists subjectively preferred the Marquee® for several measures including cocking, chamber exposure, and overall (p < 0.02 for each), while the needles were rated similarly for firing, recoil, and handling. Review of 800 cases showed no difference in major (1.0% Achieve®, 1.9% Marquee®, p = 0.5) or minor (1.5% Achieve®, 0.5% Marquee®, p = 0.3) rates of hemorrhagic complications. CONCLUSION: Liver biopsy specimens were significantly wider with Marquee® compared to Achieve®. Radiologists preferred the Marquee® for multiple tactile measures, while the major complication rate was not significantly different. While both needles have a similar side-notch design, the Marquee® needle demonstrates better sample quality and higher user preference, without compromising safety.

Needle types used in abdominal cross-sectional interventional radiology: a survey of the Society of Abdominal Radiology emerging technology commission.

PURPOSE: To identify commonly used needle types in cross-sectional interventional radiology (CSIR) and to review features and safety profiles of those needles. METHODS: Members of the Society of Abdominal Radiology (SAR) emerging technologies commission (ETC) on CSIR were sent a 13-question survey about what needles they use for common CSIR procedures: random and targeted solid organ biopsy, ultrasound-guided paracentesis, and ultrasound-guided thyroid fine needle aspiration (FNA). Results were compiled with descriptive statistics, and features of the most commonly used needles were reviewed. RESULTS: 19 surveys were completed (response rate 57.6%, 19/33) from 16 institutions. For solid organ biopsies, the majority of respondents reported using an 18-gauge needle with an automatic firing mechanism and a variable throw length option. The most commonly used needle for both random and targeted biopsies was the Argon BioPince (26.3%, 5/19) The three most commonly used needles for solid organ biopsies all featured automatic firing, variable throw length options, and 18-gauge size. A 5 French Cook Yueh needle was most the most commonly used paracentesis needle (36.8%, 7/19). For thyroid FNA, all respondents used spinal needles, and 25-gauge was the most common size (72.2%, 13/18). CONCLUSION: Abdominal radiologists use a variety of needles when performing common interventional procedures. Members of the SAR CSIR ETC commonly use automatic, 18-gauge, variable throw length needles for solid organ biopsies, 5 French catheter style needles for paracentesis, and 25-gauge spinal needles for thyroid FNA.

The Impact of an Unconventional Elective in Narrative Medicine and Pediatric Psycho-oncology on Humanism in Medical Students.

Over the course of medical school, students' optimism and hopefulness often devolve into a cynical view of medicine that continues throughout clinical rotations and beyond (Neumann et al., Acad Med 86(8):996-1009, 2011). Here, we present a qualitative evaluation of a novel immersive elective in pediatric psycho-oncology coupled with narrative medicine and its impact on students. Participants were third- and fourth-year medical students who were relieved of traditional clinical duties. Alternatively, they shadowed pediatric cancer patients, keeping narrative journals of their observations and insights. A trained team of pre-clinical medical students and faculty conducted a retrospective analysis of 120 journals written between 2008 and 2019. They compared recurring concepts to assess how blending experiential learning and reflective writing influenced the attitudes and behaviors of students. Consistent themes emerged related to developing a rich understanding of patient experiences, a humanistic appreciation of the context of illness, the ability to meaningfully reflect on insights to critically ill children, and an appreciation for the unique learning opportunity. Additionally, families expressed gratitude for the students' attentiveness to their emotional needs. By the conclusion of the elective, most students discovered that they had reignited their intrinsic empathic behaviors and were provided with beneficial insights that they believed would continue into future rotations. Experiential teaching methods paired with narrative reflection may be a valuable and therapeutic tool to learn the intricacies of the patient perspective, with the potential to enhance humanism in students during a critical time in their medical training when empathy tends to drift. Longitudinal and quantitative studies are warranted to better understand the degree and duration of specific benefits.

COVID-19 reinfection: the role of natural immunity, vaccines, and variants.

The COVID-19 pandemic has altered innumerable lives. Although recent mass vaccinations offer a glimmer of hope, the rising death toll and new variants continue to dominate the current scenario. As we begin to understand more about SARS-CoV-2 infections, the territory of reinfections with COVID-19 remains unexplored. In this review, we will discuss several aspects of reinfection: (a) How is COVID-19 reinfection characterized? (b) Does prior literature differentiate between reinfection and reactivation? (c) What SARS-CoV-2 strains do the vaccines target and can they protect against new strains? Larger and longer timeline studies are needed to understand reinfection risks. With the ongoing distribution of the SARS-CoV-2 vaccines to provide protection, the understanding of the possibility for SARS-CoV-2 reinfection remains critical. Abbreviations CDC: Centers for Disease ControlSARS-CoV-2: Severe acute respiratory syndrome coronavirus 2COVID-19: Coronavirus disease 2019RT-PCR: Reverse Transcription Polymerase Chain ReactionPASC: Post-Acute Sequelae of SARS-CoV-2 infection.

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.

Factors Influencing In-State Retention Rates of Graduating Residents From Penn State College of Medicine Compared to National Average Retention Rates.

This study analyzes in-state retention rates at Penn State University (PSU) and nationally. Data were taken from the PSU handbook with location information of graduated residents and compared to data from the Association of American Medical Colleges (AAMC). The retention rate at PSU was lower than that nationally in all but three specialties. PSU retention rate was lower than that of Pennsylvania. Pennsylvania's retention rate was lower than the national average. Community size and physician per capita may play a role in graduating resident retention rate.

Higher BMI, But Not Sarcopenia, Is Associated With Pembrolizumab-related Toxicity in Patients With Advanced Melanoma.

BACKGROUND/AIM: To determine whether BMI and sarcopenia were related to treatment-limiting toxicity or efficacy of pembrolizumab treatment in melanoma patients. PATIENTS AND METHODS: Medical records for melanoma patients undergoing pembrolizumab treatment at Duke University from January 2014 to September 2018 were reviewed. Pre-treatment measurements such as BMI were collected. Pre-treatment CT imaging was used to determine psoas muscle index (PMI). Patients in the lowest sex-specific tertile of PMI were sarcopenic. Logistic regression measured associations with treatment toxicity and response. Kaplan-Meier analysis assessed progression-free survival (PFS) and overall survival (OS). RESULTS: Among 156 patients, the overall objective response rate was 46.2% and 29 patients (18.6%) experienced treatment-limiting toxicity. Sarcopenia was not significantly associated with toxicity, response, or survival. However, obese patients (BMI >30) experienced higher rates of toxicity (p=0.0007). CONCLUSION: Sarcopenia did not appear to predict clinically relevant outcomes. Obesity, however, represents a readily available predictor of pembrolizumab toxicity.

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.

Can Texture Analysis Be Used to Distinguish Benign From Malignant Adrenal Nodules on Unenhanced CT, Contrast-Enhanced CT, or In-Phase and Opposed-Phase MRI?

OBJECTIVE: The purpose of this study is to determine whether second-order texture analysis can be used to distinguish lipid-poor adenomas from malignant adrenal nodules on unenhanced CT, contrast-enhanced CT (CECT), and chemical-shift MRI. MATERIALS AND METHODS: In this retrospective study, 23 adrenal nodules (15 lipid-poor adenomas and eight adrenal malignancies) in 20 patients (nine female patients and 11 male patients; mean age, 59 years [range, 15-80 years]) were assessed. All patients underwent unenhanced CT, CECT, and chemical-shift MRI. Twenty-one second-order texture features from the gray-level cooccurrence matrix and gray-level run-length matrix were calculated in 3D. The mean values for 21 texture features and four imaging features (lesion size, unenhanced CT attenuation, CECT attenuation, and signal intensity index) were compared using a t test. The diagnostic performance of texture analysis versus imaging features was also compared using AUC values. Multivariate logistic regression models to predict malignancy were constructed for texture analysis and imaging features. RESULTS: Lesion size, unenhanced CT attenuation, and the signal intensity index showed significant differences between benign and malignant adrenal nodules. No significant difference was seen for CECT attenuation. Eighteen of 21 CECT texture features and nine of 21 unenhanced CT texture features revealed significant differences between benign and malignant adrenal nodules. CECT texture features (mean AUC value, 0.80) performed better than CECT attenuation (mean AUC value, 0.60). Multivariate logistic regression models showed that CECT texture features, chemical-shift MRI texture features, and imaging features were predictive of malignancy. CONCLUSION: Texture analysis has a potential role in distinguishing benign from malignant adrenal nodules on CECT and may decrease the need for additional imaging studies in the workup of incidentally discovered adrenal nodules.

Comparison of Visualization Rates of LI-RADS Version 2014 Major Features With IV Gadobenate Dimeglumine or Gadoxetate Disodium in Patients at Risk for Hepatocellular Carcinoma.

OBJECTIVE: The purpose of this study is to compare visualization rates of the major features covered by Liver Imaging Reporting and Data System (LI-RADS) version 2014 in patients at risk for hepatocellular carcinoma using either gadobenate dimeglumine or gadoxetate disodium IV contrast agent. MATERIALS AND METHODS: This retrospective study included liver MRI examinations performed with either gadobenate dimeglumine or gadoxetate disodium contrast enhancement. Using age, sex, underlying liver disease, and presence of cirrhosis, patients were placed into matched cohorts. All hepatic nodules 1 cm or larger (up to five per subject) were included, resulting in 63 subjects with 130 nodules (median nodule size, 1.9 cm) imaged with gadobenate and 64 subjects with 117 nodules (median nodule size, 2.0 cm) imaged with gadoxetate. Three radiologists reviewed the studies for LI-RADS major features independently. Bootstrap resampling with 10,000 repetitions was used to compare feature detection rates. RESULTS: Arterial phase hyperenhancement was seen in a similar number of nodules with gadobenate dimeglumine (mean, 91.5% [119/130]) and gadoxetate disodium (mean, 88.0% [103/117]) (p = 0.173). Dynamic phase washout was more commonly seen with gadobenate dimeglumine (mean, 60.2% [78.3/130]) than with gadoxetate disodium (mean, 45.3% [53/117]) (p = 0.006). The capsule feature was more often visualized with gadobenate dimeglumine (mean, 50.2% [65.3/130]) than with gadoxetate disodium (mean, 33.3% [39/117]) (p < 0.001). Interreader agreement for arterial phase enhancement and dynamic phase washout was almost perfect for both contrast agents (κ > 0.83). Agreement for the capsule feature was moderate for gadobenate dimeglumine (κ = 0.52) and substantial for gadoxetate disodium (κ = 0.67). CONCLUSION: The rates of visualization of arterial phase hyperenhancement are similar in studies performed with gadobenate dimeglumine and gadoxetate disodium, but dynamic phase washout and capsule appearance are more commonly visualized with gadobenate dimeglumine.

Clinically Acceptable Optimized Dose Reduction in Computed Tomographic Imaging of Necrotizing Pancreatitis Using a Noise Addition Software Tool.

OBJECTIVE: This study aimed to determine potential radiation dose reduction of contrast-enhanced computed tomography (CECT) for imaging necrotizing pancreatitis (NP) using a noise addition tool. METHODS: Eighty-four patients were identified with at least 1 abdominopelvic CECT for NP within a 2-year period. Sixty consecutive scans were selected as reference radiation dose data sets. A noise addition software was used to simulate 4 data sets of increased noise. Readers rated confidence for identifying (i) anatomic structures, (ii) complications of NP, and (iii) diagnostic acceptability. Noise and dose levels were identified at acceptability threshold where observer scores were statistically indistinguishable from full-dose computed tomographies. RESULTS: Observers' perception of image tasks decreased progressively with increasing noise (P < 0.05). Acceptability and statistical analysis indicated that noise can be increased from 10 to 25 HU corresponding to an 84% reduction in dose without change in observer perception (P < 0.05). CONCLUSIONS: Higher image noise levels may be tolerated in CECT in patients with NP.

Early closure of fistula using neo-adjuvant intra-arterial chemotherapy in locally advanced anal cancer.

BACKGROUND: Locally advanced anal cancer patients, especially with T4 disease and fistula, have a dismal prognosis. Neo-adjuvant intra-arterial chemotherapy before standard chemoradiation has been shown to be promising in this setting. AIMS: We are reporting results from a larger patient population. METHODS: From 2005 to 2015, 25 consecutive patients with locally advanced anal cancer, 18 of them fistulised, received intra-arterial chemotherapy. RESULTS: Twenty-two of 25 patients (88%) had T4N0-3 disease and 3 (12%) T3N3. An objective tumour response was observed in 24 of 25 patients (96%): 24 partial responses and 1 with stable disease. Fistulas' complete closure was observed in 15 of 18 patients (83.3%). Following intra-arterial chemotherapy, 23 patients underwent chemoradiation. Twenty-one of 25 patients (84%) had a complete remission 6 months after treatment completion. Amongst 22 patients followed for 3 or more years, 18 of them (81%) are colostomy free at 3 years. Five-year overall survival is 75%. Most frequent grade 3-4 toxicity of IAC was neutropenia (25%). CONCLUSIONS: Neo-adjuvant intra-arterial chemotherapy combined to chemoradiation resulted in a high rate of fistulas closure and long-term control of locally advanced anal cancer. This interesting approach in the treatment of fistulised anal cancer, needs a prospective study before being considered a new standard strategy.

Diagnostic performance of imaging criteria for distinguishing autoimmune cholangiopathy from primary sclerosing cholangitis and bile duct malignancy.

OBJECTIVE: To determine the diagnostic performance of imaging criteria for distinguishing Ig-G4-associated autoimmune cholangiopathy (IAC) from primary sclerosing cholangitis (PSC) and bile duct malignancy. METHODS: A medical records search between January 2008 and October 2013 identified 10 patients (8 M, 2 F, mean age 61 years, range 34-82) with a clinical diagnosis of IAC. Fifteen cases of PSC (6 M, 9 F, mean age 50, range 22-65) and 15 cases of biliary malignancy (7 M, 8 F, mean age 65, range 48-84) were randomly selected for comparative analysis. Three abdominal radiologists independently reviewed MRI with MRCP (n = 32) or CT (n = 8) and ERCP (n = 8) for the following IAC imaging predictors: single-wall bile duct thickness >2.5 mm, continuous biliary involvement, gallbladder involvement, liver disease, peribiliary mass, or pancreatic and renal abnormalities. Each radiologist provided an imaging-based diagnosis (IAC, PSC, or cancer). Imaging predictor sensitivity, specificity, accuracy, and association with IAC using Fisher's exact test. Inter-reader agreement determined using Fleiss' kappa statistics. RESULTS: For diagnosis of IAC, sensitivities and specificities were high (70-93%). Pancreatic abnormality was strongest predictor for distinguishing IAC from PSC and cancer, with high diagnostic performance (70-80% sensitivity, 87-97% specificity), significant association (p < 0.01), and moderate inter-reader agreement (κ = 0.59). Continuous biliary involvement was moderately predictive (50-100% sensitivity, 53-83% specificity) and trended toward significant association in distinguishing from PSC (p = 0.01-0.19), but less from cancer (p = 0.06-0.62). CONCLUSION: It remains difficult to distinguish IAC from PSC or bile duct malignancy based on imaging features alone. The presence of pancreatic abnormalities, including peripancreatic rind, atrophy, abnormal enhancement, or T2 signal intensity, strongly favors a diagnosis of IAC.

Management of Anticoagulant and Antiplatelet Medications in Adults Undergoing Percutaneous Interventions.

OBJECTIVE: Many radiologists are unfamiliar with the new antithrombogenic medications and how to modify patient management before nonvascular percutaneous procedures performed in a radiology department. In this article, we review the indications for use, mechanism of action, pharmacokinetics, dosing, and recommendations for periprocedural management of patients using these medications. CONCLUSION: To improve patient safety, radiologists involved in percutaneous procedures should have knowledge of the antithrombotics that will be encountered routinely in clinical practice.

Effect of radiologists' experience with an adaptive statistical iterative reconstruction algorithm on detection of hypervascular liver lesions and perception of image quality.

PURPOSE: To prospectively evaluate whether clinical experience with an adaptive statistical iterative reconstruction algorithm (ASiR) has an effect on radiologists' diagnostic performance and confidence for the diagnosis of hypervascular liver tumors, as well as on their subjective perception of image quality. MATERIALS AND METHODS: Forty patients, having 65 hypervascular liver tumors, underwent contrast-enhanced MDCT during the hepatic arterial phase. Image datasets were reconstructed with filtered backprojection algorithm and ASiR (20%, 40%, 60%, and 80% blending). During two reading sessions, performed before and after a three-year period of clinical experience with ASiR, three readers assessed datasets for lesion detection, likelihood of malignancy, and image quality. RESULTS: For all reconstruction algorithms, there was no significant change in readers' diagnostic accuracy and sensitivity for the detection of liver lesions, between the two reading sessions. However, a 60% ASiR dataset yielded a significant improvement in specificity, lesion conspicuity, and confidence for lesion likelihood of malignancy during the second reading session (P < 0.0001). The 60% ASiR dataset resulted in significant improvement in readers' perception of image quality during the second reading session (P < 0.0001). CONCLUSIONS: Clinical experience using an ASiR algorithm may improve radiologists' diagnostic performance for the diagnosis of hypervascular liver tumors, as well as their perception of image quality.

Dual-energy multidetector CT for the characterization of incidental adrenal nodules: diagnostic performance of contrast-enhanced material density analysis.

PURPOSE: To determine whether contrast material-enhanced dual-energy multidetector computed tomography (CT) with material decomposition analysis allows differentiation of adrenal adenomas from nonadenomatous lesions and to compare findings with those of nonenhanced multidetector CT. MATERIALS AND METHODS: This retrospective HIPAA-compliant study was approved by the institutional review board of Duke University, with waiver of informed consent. Thirty-eight nonconsecutive patients (22 men and 16 women; mean age, 65 years) with 47 adrenal nodules underwent nonenhanced and contrast-enhanced dual-energy multidetector CT of the abdomen. For each adrenal nodule, nonenhanced attenuation values were recorded; dual-energy density measurements were obtained by using fat-iodine and fat-water material density basis pairs. Mean and median values of nonenhanced attenuation and material densities were compared between adenomas and nonadenomas by using the two-sample t test and Wilcoxon rank sum test, respectively. The diagnostic performance of nonenhanced multidetector CT and dual-energy material densities was assessed by setting the specificity for diagnosis of adenomas at 100%. RESULTS: Adenomas (lipid rich and lipid poor) displayed significantly different mean density values (in milligrams per cubic centimeter) than those of nonadenomas on fat-iodine (970.4 ± 17.2 vs 1012.3 ± 9.3), iodine-fat (2.5 ± 0.3 vs 4.5 ± 1.5), fat-water (-666.7 ± 154.8 vs -2141.8 ± 953.2), and water-fat (1628.4 ± 177.3 vs 3225 ± 986.1) images, respectively (P < .0001). For diagnosis of adenomas, dual-energy material density analysis showed a sensitivity of 96% (23 of 24 lesions) at a specificity of 100% (23 of 23 lesions), yielding significantly improved diagnostic performance compared with nonenhanced multidetector CT attenuation (sensitivity of 67% [16 of 24 lesions] at a specificity of 100% [23 of 23 lesions]) (P = .035). CONCLUSION: Contrast-enhanced dual-energy multidetector CT with material density analysis allows differentiation between adrenal adenomas and nonadenomas, reflecting an improved ability over nonenhanced multidetector CT for diagnosis of lipid-poor adenoma.