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Background Adrenal masses are common, but radiology reporting and recommendations for management can be variable. Purpose To create a machine learning algorithm to segment adrenal glands on contrast-enhanced CT images and classify glands as normal or mass-containing and to assess algorithm performance. Materials and Methods This retrospective study included two groups of contrast-enhanced abdominal CT examinations (development data set and secondary test set). Adrenal glands in the development data set were manually segmented by radiologists. Images in both the development data set and the secondary test set were manually classified as normal or mass-containing. Deep learning segmentation and classification models were trained on the development data set and evaluated on both data sets. Segmentation performance was evaluated with use of the Dice similarity coefficient (DSC), and classification performance with use of sensitivity and specificity. Results The development data set contained 274 CT examinations (251 patients; median age, 61 years; 133 women), and the secondary test set contained 991 CT examinations (991 patients; median age, 62 years; 578 women). The median model DSC on the development test set was 0.80 (IQR, 0.78-0.89) for normal glands and 0.84 (IQR, 0.79-0.90) for adrenal masses. On the development reader set, the median interreader DSC was 0.89 (IQR, 0.78-0.93) for normal glands and 0.89 (IQR, 0.85-0.97) for adrenal masses. Interreader DSC for radiologist manual segmentation did not differ from automated machine segmentation (

The appropriate evaluation of adrenal masses is strongly dependent on the clinical circumstances in which it is discovered. Adrenal incidentalomas are masses that are discovered on imaging studies that have been obtained for purposes other than adrenal disease. Although the vast majority of adrenal incidentalomas are benign, further radiological and biochemical evaluation of these lesions is important to arrive at a specific diagnosis. Patients with a history of malignancy or symptoms of excess hormone require different imaging evaluations than patients with incidentalomas. This document reviews imaging approaches to adrenal masses and the various modalities utilized in evaluation of adrenal lesions. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Incidentally detected adrenal nodules are common, and prevalence increases with patient age. Although most are benign, it is important for the radiologist to be able to accurately determine which nodules require further testing and which are safely left alone. The American College of Radiology incidental adrenal White Paper provides a structured algorithm based on expert consensus for management of incidental adrenal nodules. If further diagnostic testing is indicated, adrenal computed tomography is the most appropriate test in patients for nodules less than 4 cm. In addition to imaging, biochemical testing and endocrinology referral is warranted to exclude a functioning mass.

To review the current evidence and guidelines for diagnosis and management of incidental adrenal masses with a focus on the recent changes made by the American College of Radiology (ACR) Incidental Findings Committee. Incidentally detected adrenal nodules are a commonly encountered finding estimated to occur in 5–7% of the adult population. By following current recommendations, radiologists can improve patient care by efficiently determining which masses require further diagnostic testing and which masses can be considered benign and not require further follow-up.

The lack of prospective outcomes studies for many types of incidental findings limits our understanding of both their natural history and the potential efficacy of treatment. To support decision making for the management of incidental findings, major sources of uncertainty in management pathways can be mapped and analyzed using mathematical models. This process yields important insights into how uncertainty influences the best treatment decision. Here, we consider a classification scheme, grounded in decision science, which exposes various levels and types of uncertainty in the management of incidental findings and addresses (1) disease-related risks, which are considered in context of a patient's competing causes of mortality; (2) potential degrees of intervention; (3) strength of evidence; and (4) patients' treatment-related preferences. Herein we describe how categorizing uncertainty by the sources, issues, and locus can build a framework from which to improve the management of incidental findings. Accurate and comprehensive handling of uncertainty will improve the quality of related decision making and will help guide future research priorities.

Effective leaders are essential to ensure the future of radiology. Radiologists often find themselves in leadership positions despite a lack of formal leadership training. The fourth year of residency is the ideal time to expose young physicians to leadership and extraclinical specialization, as such leadership development prior to fellowship may still impact academic career choice. In this manuscript, we discuss prior successes of leadership tracks within medicine and review the evidence supporting the saying that "leaders are made, not born". Finally, we describe the evolution of our institution's residency leadership tracks highlighting key components, challenges, early successes and future endeavors.

Rationale and Objectives Quantify changes in total and by-subspecialty radiology workload due to deferring nonurgent services during the initial COVID-19 pandemic, and describe operational strategies implemented due to shifts in priority. Materials and Methods This retrospective, Institutional Review Board-exempt, study was performed between February 3, 2020 and April 19, 2020 at a large academic medical center. During March 9–15 (intervention period), nonurgent outpatient service deferments began. Five-week periods pre- (baseline) and postintervention (COVID) were defined. Primary outcomes were radiology volume (reports per day) overall and in 11 subspecialty divisions. Linear regression assessed relationship between baseline vs. COVID volumes stratified by division. Secondary outcomes included changes in relative value units (RVUs), inpatient and outpatient volumes. Results There were 62,791 baseline reports vs. 23,369 during COVID; a 60% overall precipitous volume decrease (p < 0.001). Mean volume decrease pre- and during-COVID was significant (p < 0.001) amongst all individual divisions. Mean volume decrease differed amongst divisions: Interventional Radiology experienced least disruption (29% volume decrease), 7 divisions experienced 40%–60% decreases, and Musculoskeletal, Breast, and Cardiovascular imaging experienced >75% volume decrease. Total RVUs decreased 60% (71,186 baseline; 28,476 COVID). Both outpatient and inpatient report volumes decreased; 72% (41,115 baseline; 11,326 COVID) and 43% (12,626 baseline vs. 6,845 COVID), respectively. In labor pool tracking data, 21.8% (162/744) total radiology employees were reassigned to other hospital duties during the intervention period. Conclusion Precipitous radiology workload reductions impacted subspecialty divisions with marked variation. Data-driven operational decisions during COVID-19 assisted workflow and staffing assignment changes. Ongoing adjustments will be needed as healthcare systems transition operations to a “new normal.”

Rationale and Objectives Social distancing mandates due to COVID-19 have necessitated adaptations to radiology trainee workflow and educational practices, including the radiology “readout.” We describe how a large academic radiology department achieved socially distant “remote readouts,” provide trainee and attending perspectives on this early experience, and propose ways by which “remote readouts” can be used effectively by training programs beyond COVID-19. Materials and Methods Beginning March 2020, radiologists were relocated to workspaces outside of conventional reading rooms. Information technologies were employed to allow for “remote readouts” between trainees and attendings. An optional anonymous open-ended survey regarding remote readouts was administered to radiology trainees and attendings as a quality improvement initiative. From the responses, response themes were abstracted using thematic analysis. Descriptive statistics of the qualitative data were calculated. Results Radiologist workstations from 14 traditional reading rooms were relocated to 36 workspaces across the hospital system. Two models of remote readouts, synchronous and asynchronous, were developed, facilitated by commercially available information technologies. Thirty-nine of 105 (37%) trainees and 42 of 90 (47%) attendings responded to the survey. Main response themes included: social distancing, technology, autonomy/competency, efficiency, education/feedback and atmosphere/professional relationship. One hundred and forty-eight positive versus 97 negative comments were reported. Social distancing, technology, and autonomy/competency were most positively rated. Trainees and attending perspectives differed regarding the efficiency of remote readouts. Conclusion “Remote readouts,” compliant with social distancing measures, are feasible in academic radiology practice settings. Perspectives from our initial experience provide insight into how this can be accomplished, opportunities for improvement and future application, beyond the COVID-19 pandemic.

The purposes of this study were to develop an automated process for radiologists to obtain clinical follow-up on radiology reports via HIPAA-compliant e-mail and to determine what follow-up data were collected and whether they were relevant to the radiology reports.The algorithm generated high-yield follow-up data for radiologists that may improve patient care by facilitating radiologist engagement and self-assessment.

The purpose of this study is to determine the interobserver agreement of the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for diagnosing prostate cancer using in-bore MRI-guided prostate biopsy as the reference standard.Fifty-nine patients underwent in-bore MRI-guided prostate biopsy between January 21, 2010, and August 21, 2013, and underwent diagnostic multiparametric MRI 6 months or less before biopsy. A single index lesion per patient was selected after retrospective review of MR images. Three fellowship-trained abdominal radiologists (with 1-11 years' experience) blinded to clinical information interpreted all studies according to PI-RADSv2. Interobserver agreement was assessed using Cohen kappa statistics.Thirty-eight lesions were in the peripheral zone and 21 were in the transition zone. Cancer was diagnosed in 26 patients (44%). Overall PI-RADS scores were higher for all biopsy-positive lesions (mean ± SD, 3.9 ± 1.1) than for biopsy-negative lesions (3.1 ± 1.0; p0.0001) and for clinically significant lesions (4.2 ± 1.0) than for clinically insignificant lesions (3.1 ± 1.0; p0.0001). Overall suspicion score interobserver agreement was moderate (κ = 0.45). There was moderate interobserver agreement among overall PI-RADS scores in the peripheral zone (κ = 0.46) and fair agreement in the transition zone (κ = 0.36).PI-RADSv2 scores were higher in the biopsy-positive group. PI-RADSv2 showed moderate interobserver agreement among abdominal radiologists with no prior experience using the scoring system.

Purpose To evaluate the performance of the radius, exophytic or endophytic, nearness to collecting system or sinus, anterior or posterior, and location relative to polar lines (RENAL) nephrometry and preoperative aspects and dimensions used for anatomic classification (PADUA) scoring systems and other tumor biometrics for prediction of local tumor recurrence in patients with renal cell carcinoma after thermal ablation. Materials and Methods This HIPAA-compliant study was performed with a waiver of informed consent after institutional review board approval was obtained. A retrospective evaluation of 207 consecutive patients (131 men, 76 women; mean age, 71.9 years ± 10.9) with 217 biopsy-proven renal cell carcinoma tumors treated with thermal ablation was conducted. Serial postablation computed tomography (CT) or magnetic resonance (MR) imaging was used to evaluate for local tumor recurrence. For each tumor, RENAL nephrometry and PADUA scores were calculated by using imaging-derived tumor morphologic data. Several additional tumor biometrics and combinations thereof were also measured, including maximum tumor diameter. The Harrell C index and hazard regression techniques were used to quantify associations with local tumor recurrence. Results The RENAL (hazard ratio, 1.43; P = .003) and PADUA (hazard ratio, 1.80; P.0001) scores were found to be significantly associated with recurrence when regression techniques were used but demonstrated only poor to fair discrimination according to Harrell C index results (C, 0.68 and 0.75, respectively). Maximum tumor diameter showed the highest discriminatory strength of any individual variable evaluated (C, 0.81) and was also significantly predictive when regression techniques were used (hazard ratio, 2.98; P.0001). For every 1-cm increase in diameter, the estimated rate of recurrence risk increased by 198%. Conclusion Maximum tumor diameter demonstrates superior performance relative to existing tumor scoring systems and other evaluated biometrics for prediction of local tumor recurrence after renal cell carcinoma ablation.

Purpose To determine the magnitude of subject-level and population-level cost savings that could be realized by moving from fixed-volume low-osmolality iodinated contrast material administration to an effective weight-based dosing regimen for contrast-enhanced abdominopelvic CT. Methods HIPAA-compliant, institutional review board–exempt retrospective cohort study of 6,737 subjects undergoing contrast-enhanced abdominopelvic CT from 2014 to 2015. Subject height, weight, lean body weight (LBW), and body surface area (BSA) were determined. Twenty-six volume- and weight-based dosing strategies with literature support were compared with a fixed-volume strategy used at the study institution: 125 mL 300 mgI/mL for routine CT, 125 mL 370 mgI/mL for multiphasic CT (single-energy, 120 kVp). The predicted population- and subject-level effects on cost and contrast material utilization were calculated for each strategy and sensitivity analyses were performed. Results Most subjects underwent routine CT (91% [6,127/6,737]). Converting to lesser-volume higher-concentration contrast material had the greatest effect on cost; a fixed-volume 100 mL 370 mgI/mL strategy resulted in $132,577 in population-level savings with preserved iodine dose at routine CT (37,500 versus 37,000 mgI). All weight-based iodine-content dosing strategies (mgI/kg) with the same maximum contrast material volume (125 mL) were predicted to contribute mean savings compared with the existing fixed-volume algorithm ($4,053-$116,076/strategy in the overall study population, $1-$17/strategy per patient). Similar trends were observed in all sensitivity analyses. Conclusions Large cost and material savings can be realized at abdominopelvic CT by adopting a weight-based dosing strategy and lowering the maximum volume of administered contrast material.

Selection of the most appropriate modality for image guidance is essential for procedural success. We identified specific factors contributing to failure of ultrasound-guided procedures that were subsequently performed using CT guidance. This single-center, retrospective study included 164 patients who underwent a CT-guided biopsy, aspiration/drainage, or ablation after initially having the same procedure attempted unsuccessfully with ultrasound guidance. Review of the procedure images, reports, biopsy results, and clinical follow-up was performed and the reasons for inability to perform the procedure with ultrasound guidance were recorded. Patient cross-sectional area and depth to target were calculated. Differences in area and depth were compared using general linear modeling. Depth as a predictor of an unfavorable body habitus designation was modeled using logistic regression. US guidance was successful in the vast majority of cases (97%). Of the 164 procedures, there were 92 (56%) biopsies, 63 (38%) aspirations/drainages, and 9 (5%) ablations. The most common reason for procedure failure was poor acoustic window (83/164, 51%). Other reasons included target lesion being poorly discerned from adjacent tissue (61/164, 37%), adjacent bowel gas (34/164, 21%), body habitus (27/164, 16%), and gas-containing collection (22/164, 13%). Within the biopsy subgroup, patients for whom body habitus was a limiting factor were found to have on average a larger cross-sectional area and lesion depth relative to patients whose body habitus was not a complicating factor (p

Purpose To understand radiologists’ preference and variability in phrases for expressing diagnostic certainty in radiology reports. Materials and Methods This institutional review board–approved study was part of a quality improvement initiative to improve the quality of radiology reports at a tertiary academic hospital. Sixteen phrases commonly used in radiology reports to convey diagnostic certainty were extracted from prior publications. The degree of diagnostic certainty was divided into six arbitrary categories by an expert panel. We used an anonymous online survey to query 239 radiologists at our institution regarding their preferred phrase for each category. We evaluated the distribution of preferred phrases, performed cluster analysis to find groups of phrases used to describe specific diagnostic certainty categories, and calculated Krippendorff’s α to evaluate how reliably radiologists use various phrases to express diagnostic certainty. Findings In all, 59.4% (142 of 239) of radiologists completed the survey. The most commonly preferred phrases were “consistent with” (45.1%; 64 of 142) for 100% confident, “highly suggestive of” (46.5%; 66 of 142) for very high likelihood, “most likely” (31.0%; 44 of 142) for high likelihood, “may represent” (50.7%; 72 of 142) for intermediate likelihood, “unlikely” (47.2%; 67 of 142) for low likelihood, and “very unlikely” (40.1%; 57 of 142) for very low likelihood. Cluster analysis identified six groups of phrases used to indicate a similar level of diagnostic certainty; however, Krippendorff’s α was 0.217, indicating radiologists do not consistently use the same phrases for similar degrees of confidence. Conclusion Wide variability persists among radiologists’ preferences for phrases used to convey diagnostic certainty. Interventions to improve consistency of use of these phrases may help reduce ambiguity and improve quality of radiology reports.

The purpose of this study was to determine the rate of malignancy in incidentally detected bilateral adrenal masses in patients with no known history of cancer.A retrospective search of CT reports of patients with incidentally detected bilateral adrenal nodules was performed from January 1, 2002, to January 1, 2014. Patients were excluded if they had a known cancer or suspected functioning adrenal tumor; 161 patients were included. Nodules were characterized as benign or malignant on the basis of imaging features at the index CT examination, imaging features at subsequent adrenal protocol CT or MRI, imaging stability for a minimum of 1 year, or clinical follow-up of a minimum of 2 years.Mean nodule size was 1.8 cm (range, 0.7-4.9 cm). There were no cases of primary or secondary adrenal malignancy (95% CI, 0.00-0.023). The nodules diagnosed on index CT scans were 73 adrenal adenomas and two myelolipomas. Seventy-four nodules were subsequently characterized as adrenal adenomas on the basis of imaging findings. Of the 113 indeterminate nodules that had imaging follow-up, 111 were stable at the latest follow-up examination. One nodule grew 26% over 8.1 years, and the other grew 59% over 12.4 years. Clinical follow-up of patients with 60 indeterminate nodules revealed no evidence of adrenal malignancy.No case of malignancy was found in 322 incidentally detected bilateral adrenal nodules at CT of patients without known cancer. Imaging follow-up of such lesions may be unnecessary.

Purpose To determine diagnostic yield of renal biopsies performed in patients referred for image-guided tumor ablation (IGTA) and the frequency with which biopsy results would have obviated the need for subsequent ablation. Materials and Methods Retrospective review of an internal ablation database of a single institution revealed 401 consecutive percutaneous renal mass IGTAs performed from April 2000 to April 2015. Of 401 ablations, 32 were excluded, yielding 369 ablation events in 342 patients, which represented the study cohort. Patients were subdivided into groups according to whether or not biopsy was performed. Lesions were categorized according to size, malignancy/benignity, and pathology. Results IGTA was performed with biopsy for 317/369 (85.9%) and without biopsy for 52/369 (14.1%) lesions. Overall diagnostic yield for percutaneous biopsy was 94.3% (299/317). Based on biopsy results, 82.6% (262/317) were classified as malignant or suspicious, 9.5% (30/317) were classified as likely benign, and 2.2% (7/317) were classified as definitively benign. Only definitively benign lesions were designated as obviating the need for IGTA. IGTA was supported by biopsy results in the remaining 97.8% (310/317), including renal cell carcinomas, oncocytic neoplasms, metastases, and nondiagnostic biopsy results. Conclusions Biopsy of renal masses with suspicious imaging features rarely (2.2%) obviated the need for IGTA. For patients who have undergone counseling and have elected to forgo active surveillance and surgical options, biopsy can safely be performed concomitantly with ablation.

Objective Increased attention to quality and safety has led to a re-evaluation of the classic apprenticeship model for procedural training. Many have proposed simulation as a supplementary teaching tool. The purpose of this study was to assess radiology resident exposure to procedural training and procedural simulation. Materials and Methods An IRB-exempt online survey was distributed to current radiology residents in the United States by e-mail. Survey results were summarized using frequency and percentages. Chi-square tests were used for statistical analysis where appropriate. Results A total of 353 current residents completed the survey. 37% (n = 129/353) of respondents had never used procedure simulation. Of the residents who had used simulation, most did not do so until after having already performed procedures on patients (59%, n = 132/223). The presence of a dedicated simulation center was reported by over half of residents (56%, n = 196/353) and was associated with prior simulation experience (P = 0.007). Residents who had not had procedural simulation were somewhat likely or highly likely (3 and 4 on a 4-point Likert-scale) to participate if it were available (81%, n = 104/129). Simulation training was associated with higher comfort levels in performing procedures (P Conclusions Although procedural simulation training is associated with higher comfort levels when performing procedures, there is variable use in radiology resident training and its use is not currently optimized. Given the increased emphasis on patient safety, these results suggest the need to increase procedural simulation use during residency, including an earlier introduction to simulation before patient exposure.

Use of computed tomography (CT) in medicine comes with the responsibility of its appropriate (wise) and safe (gentle) application to obtain required diagnostic information with the lowest possible dose of radiation. CT provides useful information that may not be available with other imaging modalities in many clinical situations in children and adults. Inappropriate or excessive use of CT should be avoided, especially if required information can be obtained in an accurate and time-efficient manner with other modalities that require a lower radiation dose, or non-radiation-based imaging modalities such as ultrasonography and magnetic resonance imaging. In addition to appropriate use of CT, the radiology community also must monitor scanning practices and protocols. When appropriate, high-contrast regions and lesions should be scanned with reduced dose, but overly zealous dose reduction should be avoided for assessment of low-contrast lesions. Patients' cross-sectional body size should be taken into account to deliver lower radiation dose to smaller patients and children. Wise use of CT scanning with gentle application of radiation dose can help maximize the diagnostic value of CT, as well as address concerns about potential risks of radiation. In this article, key concepts in CT radiation dose are reviewed, including CT dose descriptors; radiation doses from CT procedures; and factors and technologies that affect radiation dose and image quality, including their use in creating dose-saving protocols. Also discussed are the contributions of radiation awareness campaigns such as the Image Gently and Image Wisely campaigns and the American College of Radiology Dose Index Registry initiatives.

The objective of our study was to determine whether morphologic features of adrenal masses detected at initial contrast-enhanced MDCT can differentiate benign from malignant disease.Two hundred eleven adrenal masses (1-4 cm) detected during standard contrast-enhanced MDCT with a proven final diagnosis were retrospectively identified in 188 patients through a computer search of CT, PET/CT, and pathology reports. Three authors blinded to the diagnoses independently reviewed the contrast-enhanced MDCT images of the adrenal masses and evaluated their morphologic features: lesion margin (smooth, lobulated, or irregular), density (homogeneous or heterogeneous), and additional features of central low density and enhancing rim. Using these criteria, the readers categorized each mass as probably benign, indeterminate, or suspicious.There were 171 (81%) benign and 40 (19%) malignant adrenal masses. All malignant masses were metastases diagnosed in patients with known extraadrenal malignancy. For individual morphologic features in diagnosing malignancy, irregular margins had 30-33% sensitivity and 95-96% specificity and an enhancing rim had 5-13% sensitivity and 98-99% specificity. None of the imaging features was reliable in predicting benignity. When an adrenal mass was deemed suspicious by a reader, the sensitivities for malignancy ranged from 54% to 74% and specificities from 96% to 97%. Notably, no malignant lesions occurred in patients without a known history of cancer.At routine contrast-enhanced MDCT, adrenal masses with irregular margins or a thick enhancing rim are likely to be malignant. Smooth margins and homogeneous density can be seen in both benign and malignant adrenal masses and are insufficient for characterization.

The purpose of this study is to examine the utility of appendix MRI in evaluation of pediatric patients with right lower quadrant pain and inconclusive appendix sonography findings.A search of the radiology electronic database was performed for all appendix MRI examinations performed of pediatric patients within 24 hours after inconclusive appendix sonography from December 1, 2009, through April 26, 2012. Sixty patients underwent appendix MRI within 24 hours of inconclusive sonography and represented the study cohort. MRI examinations were reviewed independently by two radiologists blinded to the diagnosis and were graded as "positive," "negative," or "indeterminate" for acute appendicitis. The final diagnosis was established by review of the surgical and pathology reports and patients' electronic medical records.Ten of 60 patients (17%) had acute appendicitis. Both readers graded the same 12 examinations as positive and the same 48 examinations as negative for acute appendicitis, with a kappa value of 1.00 (expected agreement, 0.695). No MRI examination was interpreted as indeterminate. The sensitivity and specificity of MRI for acute appendicitis in children with inconclusive appendix ultrasound findings were 100% (95% CI, 0.72-1.00) and 96% (95% CI, 0.87-0.98), respectively. The positive predictive value for the examination was 83%, the negative predictive value was 100%, and overall test accuracy was 97%.Our study shows that MRI has a sensitivity of 100% and specificity of 96% for appendicitis in pediatric patients after inconclusive appendix sonography. We think that MRI may supplant CT as the secondary modality to follow inconclusive appendix sonography.

For assessment of the effect of varying the peak kilovoltage (kVp), the adaptive statistical iterative reconstruction technique (ASiR), and automatic dose modulation on radiation dose and image noise in a human cadaver, a cadaver torso underwent CT scanning at 80, 100, 120 and 140 kVp, each at ASiR settings of 0, 30 and 50 %, and noise indices (NIs) of 5.5, 11 and 22. The volume CT dose index (CTDIvol), image noise, and attenuation values of liver and fat were analyzed for 20 data sets. Size-specific dose estimates (SSDEs) and liver-to-fat contrast-to-noise ratios (CNRs) were calculated. Values for different combinations of kVp, ASiR, and NI were compared. The CTDIvol varied by a power of 2 with kVp values between 80 and 140 without ASiR. Increasing ASiR levels allowed a larger decrease in CTDIvol and SSDE at higher kVp than at lower kVp while image noise was held constant. In addition, CTDIvol and SSDE decreased with increasing NI at each kVp, but the decrease was greater at higher kVp than at lower kVp. Image noise increased with decreasing kVp despite a fixed NI; however, this noise could be offset with the use of ASiR. The CT number of the liver remained unchanged whereas that of fat decreased as the kVp decreased. Image noise and dose vary in a complicated manner when the kVp, ASiR, and NI are varied in a human cadaver. Optimization of CT protocols will require balancing of the effects of each of these parameters to maximize image quality while minimizing dose.

Determining practice parameters for interventional procedures is challenging due to many factors including unreliable laboratory tests to measure bleeding risk, variable usage of standardized terminology for adverse events, poorly defined standards for administration of blood products, and the growing numbers of anticoagulant and antiplatelet medications. We aim to address these and other issues faced by radiologists performing invasive procedures through a review of available literature, and experiential guidance from three academic medical centers. We discuss the significant limitations with respect to using prothrombin-time and international normalized ratio to measure bleeding risk, especially in patients with synthetic defects due to liver function. Factors affecting platelet function including the impact of uremia; recent advances in laboratory testing, including platelet function testing; and thromboelastography are also discussed. A review of the existing literature of fresh-frozen plasma replacement therapy is included. The literature regarding comorbidities affecting coagulation including malignancy, liver failure, and uremia are also reviewed. Finally, the authors present a set of recommendations for laboratory thresholds, corrective transfusions, as well as withholding and restarting medications.

The purpose of this study is to describe the prevalence and the characteristics of clinically important incidental extraurinary findings detected at MDCT urography performed for hematuria.A computer search of CT reports using the term "hematuria" identified 1209 reports of patients who had undergone MDCT urography. The results were retrospectively reviewed to determine unsuspected extraurinary findings that are clinically important or potentially important, warranting further imaging studies or medical or surgical intervention. We further categorized these important findings as acute (i.e., requiring immediate medical attention) or nonacute (i.e., requiring further evaluation in a nonurgent manner). By use of our electronic medical records, these findings were correlated to histologic diagnosis, further imaging evaluation, and clinical information.In 82 of 1209 patients (6.8%), 85 clinically important incidental extraurinary findings were identified. Follow-up evaluation was available for 43 of 85 (50.6%) findings by histologic diagnosis (n = 9), imaging evaluation (n = 31), or clinical information (n = 3). There were 11 (0.9%) examinations with acute findings, of which acute inflammation of the gastrointestinal tract and pancreaticobiliary system were the most common. Seventy-two (5.9%) examinations revealed 74 nonacute but important findings. Lung nodules were the most prevalent, followed by intraabdominal aneurysms and cystic ovarian masses. There were five (0.4%) histologically proven malignant neoplasms.The prevalence of clinically important incidental extraurinary findings at MDCT urography performed for hematuria was 6.8%.

Purpose To retrospectively evaluate the effectiveness and safety of image-guided ablation of adrenal tumors. Materials and methods : This HIPAA-compliant study was IRB approved and informed consent was waived. From 5/1999-6/2008, 20 consecutive adrenal metastases (mean diameter 4.2 cm; range, 2–8) and 3 hormonally active primary adrenal tumors (mean diameter 2.3 cm; range, 1–4), including an aldosteronoma and 2 pheochromocytomas in 22 patients (14 men, 8 women; mean age 61 years; range 40–84) were ablated in 23 sessions. Bilateral metastases were treated in a single patient. Radiofrequency ablation was used to treat 16 adrenal metastases and the 3 hyperfunctioning tumors. Microwave ablation was used to treat 4 metastases. Successful treatment was defined as a lack of both enhancement on follow-up contrast enhanced CT and/or up-take on FDG PET-CT and for functioning tumors, resolution of biochemical abnormalities. Results Technical success was achieved in all sessions. Mean follow-up was 45.1 months (range, 1–91) Local tumor progression (focal enhancement at ablation site ≥1 cm in short axis) was detected in 4 of 23 tumors, two of which were identified bilaterally in a single patient prompting re-treatment. Of 19 patients with metastatic disease, 16 had fatal extra-adrenal disease progression, and 3 remain alive. Two of the 3 patients who underwent ablation of hyperfunctioning tumors remain alive, including the patient with an aldosteronoma who had recurrent symptoms 91 months post ablation. Intra-ablative hypertension occurred in 9% (2/23) of sessions and was successfully treated pharmacologically. Conclusion Ablation of metastatic and hyperfunctioning adrenal tumors is safe and may provide local control and treatment of pathologic biochemical activity.

To determine whether placement of marking coils at biopsy of small renal neoplasms to facilitate localization at subsequent radiofrequency (RF) ablation is safe and can reduce fluoroscopy time during the ablative procedure.This retrospective study was approved by the hospital institutional review board and was compliant with HIPAA. The requirement to obtain informed consent was waived. A search of the renal RF ablation database (235 patients) identified 23 consecutive patients who had a marking coil placed at biopsy of a renal neoplasm (coil group) and 23 patients who did not have a marking coil placed at biopsy (control group). The patients were matched for tumor characteristics, including size, parenchymal position, location in the kidney, and laterality. All patients underwent subsequent RF ablation. The authors compared computed tomographic (CT) fluoroscopy times and technical success rates between the two groups. Statistical analyses were performed by using a single-tailed paired t test for comparison of CT fluoroscopy times, a two-tailed paired t test for comparison of age and tumor size, and a single-tailed McNemar test for comparison of the technical success rate of ablation.The mean CT fluoroscopy time for the RF ablation procedure was 28 seconds ± 11.7 (standard deviation) for the coil group and 66 seconds ± 85.8 for the control group (P = .025). There was no significant difference in the technical success rates of renal RF ablation.For small renal neoplasms that are poorly visualized at unenhanced CT, placement of a metallic marking coil at biopsy facilitates tumor localization, thus reducing CT fluoroscopy time and radiation dose for subsequent RF ablation procedures.

The authors explore the benefits and risks of not reporting imaging findings that do not have clinical relevance, with the goal of developing recommendations to reduce their reporting. The authors review the example of incidentally detected, simple renal cysts (Bosniak category I), including medicolegal conditions required for such a shift in reporting practices to be acceptable. The authors propose four potential criteria for not reporting clinically unimportant findings and recommend that these criteria be debated in other contexts, so that they can be refined and implemented.

With increasing emphasis on minimally invasive nephron-sparing techniques for treatment of renal tumors, image-guided percutaneous radiofrequency ablation (RFA) has emerged as a safe and effective method of tumor eradication that may be performed on an outpatient basis, with relatively low morbidity and mortality. This review addresses the clinical and technical considerations, risks, complications, and currently reported efficacy data pertaining to RFA of renal tumors, as well as the standardized approach to treatment and follow-up currently used in our practice.

The objective of our study was to report the incidence of multiple sporadic primary renal cell carcinomas (RCCs) in patients referred for radiofrequency ablation (RFA).A retrospective search identified 162 patients (104 men and 58 women; mean age, 74 years) without a history of von Hippel-Lindau disease with a total of 175 tumors treated with RFA for biopsy-proven primary renal malignancies at our institution from 1998 to 2009. Three groups of patients with multiple RCCs were identified: patients with a history of nephrectomy for RCC who had been referred for RFA of a new renal tumor, patients who presented with multiple renal tumors at the time of referral for RFA, and patients who were shown to have developed a new renal tumor on follow-up imaging after RFA.Twenty-eight patients (17%) had multiple biopsy-proven RCCs. Eighteen patients (11%) had undergone prior nephrectomy for surgically proven RCC. The mean interval between prior nephrectomy and RFA referral was 122 months (range, 12-456 months). Seven patients (4%) without a history of nephrectomy presented with two biopsy-proven RCCs at RFA referral. Three patients (2%) who had not undergone nephrectomy and had a solitary RCC at the time of RFA had developed a new biopsy-proven RCC separate from the original treatment site on follow-up imaging after RFA. The mean time to diagnosis from the initial RFA treatment was 52 months (range, 25-89 months).Imaging surveillance of patients referred for renal RFA may be important not only to assess treatment success but also to detect new RCCs.

To determine if use of an electromagnetic navigation system (EMN) decreases radiation dose and procedure time of CT fluoroscopy guided lung biopsy in lesions smaller than 2.5 cm.86 consecutive patients with small lung masses (2.5 cm) were approached. 60 consented and were randomized to undergo biopsy with CT fluoroscopy (CTF) (34 patients) or EMN (26 patients). Technical failure required conversion to CTF in 8/26 EMN patients; 18 patients completed biopsy with EMN. Numerous biopsy parameters were compared as described below.Average fluoroscopy time using CTF was 28.2s compared to 35.0 s for EMN (p=0.1). Average radiation dose was 117 mGy using CTF and 123 mGy for EMN (p=0.7). Average number of needle repositions was 3.7 for CTF and 4.4 for EMN (p=0.4). Average procedure time was 15 min for CTF and 20 min for EMN (p=0.01). There were 7 pneumothoracesin the CTF group and 6 pneumothoraces in the EMN group (p=0.7). One pneumothorax in the CTF group and 3 pneumothoraces in the EMN group required chest tube placement (p=0.1). One pneumothorax patient in each group required hospital admission. Diagnostic specimens were obtained in 31/34 patients in the CTF group and 22/26 patients in the EMN group (p=0.4).EMN was not statistically different than CTF for fluoroscopy time, radiation dose, number of needle repositions, incidence of pneumothorax, need for chest tube, or diagnostic yield. Procedure time was increased with EMN.

Adrenal masses are common incidental findings on cross-sectional imaging. Most of these masses are benign, and adenomas are the most common entity. Several imaging studies allow accurate diagnosis of these masses, separating inconsequential benign masses from the lesions that require treatment. This article discusses contemporary adrenal imaging and the optimal algorithm for the workup of incidentally detected adrenal masses.

To prospectively compare the effect of intravenous injection of low-osmolar iopamidol with that of intravenous injection of iso-osmolar iodixanol on heart rate (HR) during nongated chest computed tomographic (CT) angiography.This multicenter study was approved by local institutional review boards, and patients provided written informed consent. Patient enrollment and examination at centers in the United States complied with HIPAA regulations. One hundred and thirty patients (54 male; mean age, 52 years) clinically suspected of having pulmonary embolism were referred for pulmonary CT angiography and were randomly assigned to receive 80 mL of either iopamidol (370 mg of iodine per milliliter, n = 63) or iodixanol (320 mg of iodine per milliliter, n = 67) at a rate of 4 mL/sec. HR (measured in beats per minute) was monitored from 5 minutes before the start of injection to the end of imaging, and precontrast HR and maximum postcontrast HR were recorded. Student t and χ(2) tests were used for continuous and categorical variables, respectively.Precontrast HR in patients who received iopamidol (mean, 81 beats per minute ± 18 [standard deviation]) was similar to that in patients who received iodixanol (mean, 77 beats per minute ± 17) (P = .16). Mean postcontrast HR was 87 beats per minute ± 17 and 82 beats per minute ± 18 (P = .16) in the iopamidol and iodixanol groups, respectively. Mean increase from precontrast HR to postcontrast HR was 5 beats per minute ± 9 and 5 beats per minute ± 7 (P = .72) in the iopamidol and iodixanol groups, respectively. Thirty-five (56%) of the 63 patients who received iopamidol and 33 (49%) of the 67 patients who received iodixanol had an HR increase of fewer than 5 beats per minute, 15 (24%) and 18 (27%) patients, respectively, had an increase of 5-9 beats per minute, and four (6%) and three (4%) patients, respectively, had an increase of more than 20 beats per minute. These proportions were not significantly different between the groups (P = .51, χ(2) test).High-rate intravenous administration of 80 mL of iopamidol and iodixanol during pulmonary CT angiography slightly increased HR; there was no difference in HR between the contrast agent groups.

The objective of our study was to evaluate the accuracy of dynamic contrast-enhanced 4D MDCT in the preoperative identification of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT) and a history of failed surgery or unsuccessful localization on standard imaging.Thirty-four patients with PHPT underwent 4D CT. Retrospective blinded review of the 4D CT examinations was performed by three radiologists for the presence and location of a suspected parathyroid adenoma or adenomas. At the time of the study, 25 patients underwent surgical exploration after 4D CT. Twenty patients had solitary parathyroid adenomas, two patients had two adenomas resected, two patients did not have an adenoma, and one patient had mild four-gland hyperplasia. One patient did not have PHPT on repeat serum biochemistry. Surgical and pathology reports, adenoma enhancement, and biochemical and clinical follow-up were reviewed. Data were compared with 4D CT interpretations and interobserver reliability was calculated.The mean sensitivity and specificity of the three readers for the precise CT localization of adenomas was 82% (range, 79-88%) and 92% (range, 75-100%), respectively. Overall interobserver reliability was excellent (κ = 0.70; range, κ = 0.60-0.79). All adenomas resected at surgery showed a biochemical response and clinical response. The mean densities of the confirmed adenomas were 41, 128, 138, and 109 HU at 0, 30, 60, and 90 seconds, respectively. Level II lymph nodes identified in 10 patients showed significantly less enhancement at 30 (p = 0.0001) and 60 (p = 0.006) seconds compared with surgically proven adenomas.Occult parathyroid adenoma shows characteristic early enhancement. In this subset of patients, 4D CT may improve surgical outcomes and decrease morbidity.

Received November 14, 2008; accepted after revision November 4, 2009. 1Department of Diagnostic Imaging, The Warren Alpert Medical School of Brown University, Women and Infants Hospital, Rhode Island Hospital, 593 Eddy St., Providence, RI 02903. Address correspondence to C. A. Woodfield (courtneywoodfield@yahoo.com). 2Present address: Department of Radiology, University of California at San Diego, San Diego, CA. AJR 2010;194:S42–S45 0361–803X/10/1946–S42 © American Roentgen Ray Society ABSTRACT The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of the imaging evaluation of abdominal pain during pregnancy.

To review the recurrence patterns in patients with primary non-small cell lung cancer (NSCLC) treated with percutaneous image-guided radiofrequency (RF) ablation.This retrospective review was institutional review board approved and HIPAA compliant. Informed consent was waived. Data from all patients with primary NSCLC who underwent lung RF ablation from January 1998 to January 2008 were reviewed. Ninety-one patients were identified. Ten patients with no posttreatment imaging results and two patients with multiple treated lung cancers were excluded. There were 79 tumors in 79 patients (mean age, 75 years). Mean tumor size was 2.5 cm (range, 1-5.5 cm). Fifteen (19%) tumors were central, and 64 (81%) tumors were peripheral. Nineteen (24%) patients underwent adjuvant external beam radiation, and nine (11%) patients underwent concomitant brachytherapy. Correlation of computed tomography and positron emission tomography imaging studies with biopsy results, tumor size, location, and stage was performed. Patterns of recurrence were classified as local, intrapulmonary, nodal, mixed (local and nodal), and distant.Forty-five (57%) patients demonstrated no evidence of recurrence at follow-up imaging (range, 1-72 months; mean, 17 months). Recurrence was seen in 34 (43%) patients (range, 2-48 months; mean, 14 months). Recurrence after RF ablation was local in 13 (38%), intrapulmonary in six (18%), nodal in six (18%), mixed in two (6%), and distant metastases in seven (21%) cases. Median disease-free survival was 23 months. Sex, tumor location, and radiation therapy were not associated with risk of recurrence. Increasing tumor size (P = .02) and stage (P = .007) were related to risk of recurrence.The most common pattern of recurrence was local, which suggests that more aggressive initial RF ablation and adjuvant radiation may offer improvement in outcomes. Continued follow-up imaging is needed because new recurrences were seen throughout the 2 years following treatment.

To describe the incidence and clinical importance of the renal halo sign after percutaneous radiofrequency ablation (RFA) of renal neoplasms.Institutional review board approval was obtained for this HIPAA-compliant retrospective study. The study population consisted of 101 consecutive patients with 106 solid renal neoplasms that were treated with percutaneous RFA. Postablation computed tomographic (CT) and magnetic resonance (MR) images were retrospectively reviewed by three board-certified radiologists to determine the presence of the renal halo sign. Statistical analyses were performed to determine reader agreement and assess the effect that tumor size and location, radiofrequency (RF) applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed had on development of the renal halo sign.The renal halo sign developed in 79 (75%) of the 106 ablated tumors. Average imaging follow-up lasted 25 months (range, 1-98 months). The renal halo sign appeared, on average, 6 months (range, 1 month to 3 years) after RFA. The renal halo sign resolved in five (6%) of 79 tumors treated. Interobserver agreement for the presence of the renal halo sign was high. Tumor size and location, RF applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed were not independent predictors of renal halo sign development.The renal halo sign is seen in 75% of patients after percutaneous RFA of renal neoplasms. It may decrease in size over time; however, it rarely disappears. It is important to recognize this sign, as it can be mistaken for recurrent tumor or angiomyolipoma by radiologists who are not familiar with RFA.

Aim To evaluate the sensitivity and specificity of eight previously reported computed tomography (CT) signs in diagnosing internal mesenteric hernia following Roux-en-Y gastric bypass surgery. Materials and methods Preoperative CT images of nine patients with surgically proven internal mesenteric hernia as a complication of gastric bypass surgery and 10 matched control patients were reviewed in a blinded fashion by three radiologists. The presence of eight previously reported signs of internal mesenteric hernia was assessed: mesenteric swirl sign, hurricane eye sign, mushroom sign, small bowel obstruction, clustered small bowel loops, small bowel other than duodenum located behind the superior mesenteric artery (SMA), presence of the jejunal anastomosis to the right of the midline, and engorged mesenteric lymph nodes. The sensitivity and specificity were calculated for each sign, as well as inter-observer reliability in recognizing these signs. Results Mesenteric swirl was the most predictive sign of internal hernia (sensitivity 78–100%, specificity 80–90%). Other CT signs showed good specificity (70–100%), but sensitivities were low (0–44%). The presence of a small-bowel obstruction and engorged mesenteric nodes was found to be 100% specific in predicting the presence of an underlying hernia. There was substantial inter-observer agreement in detecting mesenteric swirl sign (κ = 0.48–0.79), but agreement was relatively poor for all other signs. Conclusion Mesenteric swirl is an easily recognized CT sign, and is the best indicator of internal hernia following Roux-en-Y gastric bypass surgery. Other reported CT signs are diagnostically insensitive. The presence of small-bowel obstruction with engorged mesenteric nodes is highly specific in diagnosing internal mesenteric hernia.

Adrenal tumors represent a diverse group of neoplasms that include multiple etiologies, each with a different prognosis, malignant potential, and recommended treatment. Percutaneous techniques to treat adrenal neoplasms have been described including radiofrequency ablation, cryoablation, and chemical ablation. This article reviews the various adrenal neoplasms and the techniques of adrenal ablation.

The objective of this study was to report the clinical outcome of patients with an appendicolith on computed tomography (CT) who did not undergo appendectomy on initial presentation. Reports from 45,901 abdominal CT examinations performed between March 2000-March 2004 containing the words "appendicolith" or "fecalith" were identified. Patients with appendicoliths not initially undergoing appendectomy were followed to assess re-presentation with abdominal pain ultimately requiring appendectomy. Seventy-four patients had an appendicolith on CT report, were discharged without surgery, and had clinical follow-up. Fifty-two of 74 (70%) patients had no appendiceal symptoms, were given an alternate diagnosis, and did not return with appendicitis. Twenty-two of 74 (30%) patients were discharged without acute appendicitis but with possible appendiceal symptoms. Five of these 22 (23%) patients returned with pathologically proven acute appendicitis, and all had possible appendiceal symptoms at initial presentation. An appendicolith may be a marker of increased risk for appendicitis but is not an indication for appendectomy.

PURPOSE To evaluate the clinical outcomes in patients with early-stage non–small-cell lung cancer (NSCLC) after combined treatment with thermal ablation and radiation therapy (RT). MATERIALS AND METHODS Forty-one patients with inoperable stage I/II NSCLC tumors underwent thermal ablation and RT at our institution between 1998 and 2005. Thirty-seven radiofrequency (RF) ablation procedures and four microwave ablation procedures were performed. Ablations were followed by standard-fraction external-beam RT within 90 days ( n = 27) or postprocedural brachytherapy ( n = 14). Survival and local recurrence were the primary endpoints evaluated by Kaplan-Meier analysis. RESULTS The median follow-up was 19.5 months. The overall survival rates were 97.6% at 6 months, 86.8% at 1 year, 70.4% at 2 years, and 57.1% at 3 years. Patients with tumors smaller than 3 cm ( n = 17) had an average survival time of 44.4 ± 5.4 months (SE). Patients with tumors 3 cm or larger ( n = 24) had an average survival time of 34.6 ± 7.0 months ( P = .08). Local recurrence occurred in 11.8% of tumors smaller than 3 cm after an average of 45.6 ± 4.1 months and in 33.3% of the larger tumors after an average of 34.0 ± 7.8 months ( P = .03). Outcomes in the brachytherapy and RT groups did not differ significantly. Nine of 15 pneumothoraces required chest tube drainage (22.0%). CONCLUSIONS Thermal ablation followed by RT for inoperable stage I/II NSCLC has a relatively low rate of complications that are easily managed. Combined therapy may result in an improved survival compared with either modality alone.

Computed tomography (CT) is an imaging test that is widely used worldwide to establish medical diagnoses and perform image-guided interventions. More recently, concern has been raised about the risk of carcinogenesis from medical radiation, with a focus on CT. The purpose of this article is to (a) describe the importance of educating radiology personnel, patients, and referring clinicians about the concerns over CT radiation, (b) describe commonly used CT parameters and radiation units, (c) discuss the importance of establishing a dedicated radiology team to manage CT radiation, and (d) describe specific CT techniques to minimize radiation while providing diagnostic examinations.

The purpose of this study is to describe the CT appearance of thoracic neoplasms after treatment with radiofrequency ablation (RFA).Thirty-two thoracic neoplasms in 26 patients had pulmonary RFA and imaging follow-up. Fourteen neoplasms were primary lung cancer and 18 were metastases. The mean pretreatment neoplasm size was 3.1 cm (range, 1.0-7.0 cm), and the average number of neoplasms treated per patient was 1.2 (range, 1-3). The mean follow-up was 10.1 months (range, 1-30 months). Imaging findings on CT were evaluated by three radiologists and documented by consensus.The most common finding immediately after treatment was peripheral ground-glass opacity surrounding the treated neoplasm, seen in 27 of 32 tumors (84%). This rapidly resolved in all but one patient by the end of the first month. Cavitation was seen in 10 of 32 tumors (31%) on follow-up CT and was most common in neoplasms in the inner two thirds of the lung and adjacent to a segmental bronchus. Sixty percent of the cavitations decreased in size on follow-up scans. Ten of 32 tumors (31%) that did not develop cavitation developed bubble lucencies on follow-up CT. Pleural thickening was found in 12 of 22 (55%) parenchymal neoplasms, and linear opacifications were seen between the treated lesion and adjacent pleura in 14 of 22 parenchymal tumors (64%). Pleural effusions were seen in four patients (15%). Fourteen of 22 tumors (64%) with follow-up imaging at 1 month enlarged from pretreatment CT scans. At 3 and 6 months after RFA, the majority remained stable in size.Peripheral ground-glass opacity, cavitation, bubble lucencies, and pleural changes are common findings on CT after RFA. Many treated neoplasms increase in size from baseline on 1- to 3-month follow-up CT scans and then remain stable thereafter. Enlargement of a treated tumor after 6 months is felt to represent local recurrence. Stability of a treated lesion beyond 6 months does not guarantee continued stability.