Investigating new CT contrast agents: a phantom study exploring quantification and differentiation methods for high-Z elements using dual-energy CT.

OBJECTIVES: To develop a dual-energy CT method for differentiating and quantifying high-Z contrast elements and to evaluate the limitations based on element concentration and atomic number by using an anthropomorphic phantom study. METHODS: Mass spectrometry standards for iodine, barium, gadolinium, ytterbium, tantalum, gold, and bismuth were diluted from 10.0 to 0.3 mg/mL, placed inside 7-mL vials, and scanned with dual-energy CT using an abdominal phantom and cylindrical water-filled insert. This procedure was repeated with all seven high-Z elements at six isoattenuating values from 250 to 8 HU. Quantification accuracy was measured using a linear regression model and residual error analysis with 90% limits of agreement. The limit of detection for each element was evaluated using the limit of blank of water. Pairwise differentiation of isoattenuating vials was evaluated using AUC values and the difference in fit angles between the two elements. RESULTS: Each high-Z element had a unique concentration vector in a two-dimensional plot of Compton scattering versus photoelectric effect attenuations. Mean quantification values were within ± 0.1 mg/mL of the true values for each element with no proportional bias. Limits of detection ranged from 0.35 to 0.56 mg/mL. Pairwise differentiations were proportional to the isoattenuating HU and the angle between the linear fits with mean AUC values increasing from 0.61 to 0.98 at 8 to 250 HU, respectively. CONCLUSION: Dual-energy CT can differentiate and quantify isoattenuating high-Z elements. The high-attenuation characteristics and unique concentration vectors of ytterbium, tantalum, gold, and bismuth are well suited for new dual-energy CT contrast agents especially when simultaneously imaged with iodine, barium, or gadolinium. KEY POINTS: • Dual-energy CT can accurately quantify high-Z contrast elements and readily differentiate iodine, barium, and gadolinium from ytterbium, tantalum, gold, and bismuth. • The differentiation and quantification capabilities for high-Z contrast elements are largely unaffected by phantom size and transaxial location within the phantom. • Potential benefits of new CT contrast agents based on these high-Z elements include alternatives for patients with iodine sensitivity, high conspicuity at both 120 and 140 kVp, simultaneous imaging of two contrast agents, and reduced injection volume.

Abbreviated-protocol screening MRI vs. complete-protocol diagnostic MRI for detection of hepatocellular carcinoma in patients with cirrhosis: An equivalence study using LI-RADS v2018.

BACKGROUND: The high operational cost of MRI limits its utility for hepatocellular carcinoma (HCC) screening. Abbreviated-protocol dynamic contrast-enhanced MRI (aMRI) may help lower cost while maintaining the high accuracy of complete-protocol diagnostic MRI (cMRI). PURPOSE: To compare aMRI to cMRI for HCC detection in cirrhosis patients. STUDY TYPE: Cross-sectional study. STUDY POPULATION: Cirrhosis patients undergoing MRI for suspected HCC. FIELD STRENGTH/SEQUENCE: 1.5T and 3T; aMRI (coronal T2 -weighted, axial dynamic contrast-enhanced T1 -weighted fat-suppressed sequences); cMRI (aMRI sequences and unenhanced axial T2 -, T1 -, and diffusion-weighted sequences). ASSESSMENT: From each cMRI, an abbreviated exam was created by extracting only the aMRI sequences. Five radiologists independently reviewed aMRI and cMRI and assigned per-patient screening results by the presence/absence of any actionable observation per Liver Imaging and Reporting Data System v2018 (LI-RADS 4, 5, M, or TIV categories). Per-patient HCC status was determined by the composite reference standard of histopathology, follow-up imaging, consensus expert panel imaging review, and clinical follow-up. STATISTICAL TESTS: Interreader agreement between aMRI and cMRI was compared with that of cMRI and tested for interchangeability against a tolerance margin of 0.05. Per-patient screening sensitivity, specificity, and accuracy were compared between aMRI and cMRI and tested for equivalence against a tolerance margin of 0.05. RESULTS: In 93 cirrhosis patients, five radiologists recorded on average 121 liver observations. Interreader screening agreement probability (and 95% confidence interval confidence interval [CI]) was 0.914 [0.900, 0.926] between aMRI and cMRI, and 0.927 [0.908, 0.942] for cMRI; their difference was within the 0.05 margin for interchangeability. In 86 patients in whom a final HCC status could be determined, the detection sensitivity and specificity of aMRI was 0.921 [0.864, 0.956] and 0.886 [0.844, 0.918], within the 5% equivalence margin to cMRI, 0.936 [0.881, 0.965] and 0.883 [0.840, 0.915], respectively. DATA CONCLUSION: Abbreviated-protocol screening MRI is interchangeable with, and equivalent to, complete-protocol diagnostic MRI for per-patient HCC detection in cirrhosis. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 6 J. Magn. Reson. Imaging 2020;51:415-425.

A Technique to Identify Isoattenuating Gallstones with Dual-Layer Spectral CT: An ex Vivo Phantom Study.

Background Previously reported dual-energy CT methods for detecting noncalcified gallstones have reduced accuracy for gallstones smaller than 9 mm. Purpose To develop a dual-energy CT method for differentiating isoattenuating gallstones from bile and compare it with previously reported dual-energy CT methods by using a prospective ex vivo phantom reader study. Materials and Methods From May 2017 to May 2018, gallstones were collected from 105 patients (34 men; mean age, 51 years; age range, 18-84 years) undergoing cholecystectomy and placed inside 120-mL vials containing ox bile. The vials were placed inside a water-filled phantom and were scanned with dual-layer dual-energy CT. Thirty isoattenuating gallstones (4.3-24.7 mm in diameter) were evaluated. Conventional CT images, virtual noncontrast images, and monoenergetic images at 200 and 40 keV were created. Segmented images were created by using a two-dimensional histogram of Compton and photoelectric attenuation. Six readers evaluated the presence of isoattenuating gallstones in each image. Intra- and interreader agreement was measured by using percentage agreement, diagnostic performance was evaluated by using mean area under the receiver operating characteristic curve (AUC) estimates and pairwise comparisons, and the agreement of gallstone sizes measured at pathologic examination with those measured on segmented images was compared by using Bland-Altman analysis. Results For all gallstones, segmented images provided the highest mean intrareader (88.1%) and interreader (88.2% and 93.6%) agreements for all readers and reading sessions and the highest overall AUC (0.99; 95% confidence interval [CI]: 0.97, 1.00; adjusted P < .02 for all). For gallstones larger than 9 mm, no significant difference was found between the segmented and monoenergetic AUCs (all P > .94, adjusted P > .05 for all). For gallstones measuring 9 mm or smaller, the segmented images had the highest overall AUC (0.99; 95% CI: 0.97, 1.00; adjusted P < .01 for all). The mean difference in stone sizes was -0.6 mm, with limits of agreement from 2.6 to -3.8 mm. Conclusion Segmented images from Compton and photoelectric attenuation coefficients improve detection of isoattenuating gallstones compared with previously reported dual-energy CT methods. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Matos in this issue.

Breast ultrasound utilization in a safety net emergency department.

PURPOSE: The purpose of this study is to (1) assess the diagnostic yield of ultrasounds performed in the emergency department for suspected breast abscess and determine the rates of reimaging, discordance, and emergent intervention in a large, busy safety net hospital and (2) determine clinical factors significantly associated with abscess as a way to improve patient selection for emergent breast ultrasounds. METHODS: A total of 581 consecutive breast ultrasounds performed in the emergency department for suspected abscess over 15 months were retrospectively reviewed for imaging, demographics, laboratory data, and physical exam findings. Breast abscess was confirmed by combining imaging, clinical, and laboratory data. Linear logistic regression analysis estimated the likelihood of abscess, and the cross-validated area under the receiver operating characteristic curve (AUC) evaluated diagnostic performance. RESULTS: Final diagnoses included abscess (153/581, 26%), cancer (29/581, 5%), granulomatous mastitis (41/581, 7%), normal (120/581, 21%), and other/indeterminate (238/581, 41%). Factors associated with abscess included induration, fluctuance, erythema, drainage, smoking, diabetes, and Black race. Based on these factors, the AUC of the characteristics predictive of abscess was 0.77 (CI, 0.72-0.81). Six breast cancers were not diagnosed on ultrasound. 40% of ultrasounds (231/581) were considered incomplete/inadequate. CONCLUSION: 74% (428/581) of emergent breast ultrasounds in our population were negative for abscess, while 21% (6/29) of cancers were not diagnosed, and 40% (231/581) of exams were incomplete/inadequate. Patient selection for emergent ultrasounds can be improved, allowing patients with a low likelihood of abscess to be imaged in a more optimal setting.

Diagnostic Performance and Interreader Agreement of a Standardized MR Imaging Approach in the Prediction of Small Renal Mass Histology.

Purpose To assess the diagnostic performance and interreader agreement of a standardized diagnostic algorithm in determining the histologic type of small (≤4 cm) renal masses (SRMs) with multiparametric magnetic resonance (MR) imaging. Materials and Methods This single-center retrospective HIPAA-compliant institutional review board-approved study included 103 patients with 109 SRMs resected between December 2011 and July 2015. The requirement for informed consent was waived. Presurgical renal MR images were reviewed by seven radiologists with diverse experience. Eleven MR imaging features were assessed, and a standardized diagnostic algorithm was used to determine the most likely histologic diagnosis, which was compared with histopathology results after surgery. Interreader variability was tested with the Cohen κ statistic. Regression models using MR imaging features were used to predict the histopathologic diagnosis with 5% significance level. Results Clear cell renal cell carcinoma (RCC) and papillary RCC were diagnosed, with sensitivities of 85% (47 of 55) and 80% (20 of 25), respectively, and specificities of 76% (41 of 54) and 94% (79 of 84), respectively. Interreader agreement was moderate to substantial (clear cell RCC, κ = 0.58; papillary RCC, κ = 0.73). Signal intensity (SI) of the lesion on T2-weighted MR images and degree of contrast enhancement (CE) during the corticomedullary phase were independent predictors of clear cell RCC (SI odds ratio [OR]: 3.19; 95% confidence interval [CI]: 1.4, 7.1; P = .003; CE OR, 4.45; 95% CI: 1.8, 10.8; P < .001) and papillary RCC (CE OR, 0.053; 95% CI: 0.02, 0.2; P < .001), and both had substantial interreader agreement (SI, κ = 0.69; CE, κ = 0.71). Poorer performance was observed for chromophobe histology, oncocytomas, and minimal fat angiomyolipomas, (sensitivity range, 14%-67%; specificity range, 97%-99%), with fair to moderate interreader agreement (κ range = 0.23-0.43). Segmental enhancement inversion was an independent predictor of oncocytomas (OR, 16.21; 95% CI: 1.0, 275.4; P = .049), with moderate interreader agreement (κ = 0.49). Conclusion The proposed standardized MR imaging-based diagnostic algorithm had diagnostic accuracy of 81% (88 of 109) and 91% (99 of 109) in the diagnosis of clear cell RCC and papillary RCC, respectively, while achieving moderate to substantial interreader agreement among seven radiologists. © RSNA, 2018 Online supplemental material is available for this article.

Reproducibility of Index Lesion Size and Mean Apparent Diffusion Coefficient Values Measured by Prostate Multiparametric MRI: Correlation With Whole-Mount Sectioning of Specimens.

OBJECTIVE: The purpose of this study is to determine the intra- and interreader agreement for index lesion size and mean apparent diffusion coefficient (ADC) value measurements performed by five readers using whole-mount histopathologic specimens processed with a patient-specific, MRI-based, 3D-printed mold as the standard of reference. MATERIALS AND METHODS: All men who underwent multiparametric MRI of the prostate performed using a 3-T scanner with endorectal and phased-array surface coils, followed by prostatectomy conducted between November 2015 and July 2016 at our institution, were identified. MRI examinations were independently reviewed by five readers with varying degrees of experience, two of whom had essentially no experience in prostate MRI interpretation before the study, to assess index lesion size and ADC values. A linear mixed model-based intraclass correlation was used to assess intra- and interreader reader agreement for lesion size and ADC measurements and agreement for size measurements between pathologic analysis and readers. RESULTS: A total of 80 men met the study eligibility criteria. Overall inter- and intrareader agreement for ADC measurements was excellent, with interclass correlation coefficient (ICC) values of 0.84 and 0.90, respectively; both inter- and intrareader agreement between experienced readers (0.82 and 0.92, respectively) and inexperienced readers (0.86 and 0.87, respectively) were excellent as well. The agreement between mean lesion size on imaging and histopathologic analysis ranged from poor (0.32) to good (0.66), with overall agreement considered fair (0.49). CONCLUSION: Readers with varying degrees of experience achieved good-to-excellent agreement for index lesion size and ADC values on multiparametric MRI of men with prostate cancer. This degree of reproducibility may improve preoperative risk stratification, informed decision making, and treatment planning for men with known or suspected prostate cancer.

Diagnostic Utility of a Likert Scale Versus Qualitative Descriptors and Length of Capsular Contact for Determining Extraprostatic Tumor Extension at Multiparametric Prostate MRI.

OBJECTIVE: The purpose of this study is to determine the reproducibility and diagnostic performance of a Likert scale in comparison with the European Society of Urogenital Radiology (ESUR) criteria and tumor-pseudocapsule contact length (TCL) for the detection of extraprostatic extension (EPE) at multiparametric MRI. MATERIALS AND METHODS: This was a retrospective review of all men who underwent multiparametric MRI followed by prostatectomy between November 2015 and July 2016. Multiparametric 3-T MRI studies with an endorectal coil were independently reviewed by five readers who assigned the likelihood of EPE using a 1-5 Likert score, ESUR criteria, and TCL (> 10 mm). EPE outcome (absent or present) for the index lesion at whole-mount histopathologic analysis was the standard of reference. Odds ratios (ORs) and areas under the ROC curve (Az) were used for diagnostic accuracy. The interreader agreement was determined using a weighted kappa coefficient. A p < 0.05 was considered significant. RESULTS: Eighty men met the eligibility criteria. At univariate analysis, the Likert score showed the strongest association (OR, 1.8) with EPE, followed by prostate-specific antigen level (OR, 1.7), ESUR score (OR, 1.6), and index lesion size (OR, 1.2). At multivariable analysis, higher Likert score (OR, 1.8) and prostate-specific antigen level (OR, 1.6-1.7) were independent predictors of EPE. The Az value for Likert scores was statistically significantly higher (0.79) than that for TCL (0.74; p < 0.01), but not statistically significantly higher than the value for ESUR scores (0.77; p = 0.17). Interreader agreement with Likert (κ = 0.52) and ESUR scores (κ = 0.55) was moderate and slightly superior to that for TCL (κ = 0.43). Except for TCL among inexperienced readers (κ = 0.34), reader experience did not affect interreader agreement. CONCLUSION: A Likert score conveying the degree of suspicion at multiparametric MRI is a stronger predictor of EPE than is either ESUR score or TCL and may facilitate informed decision making, patient counseling, and treatment planning.

Unintended Consequences of Systemic and Ablative Oncologic Therapy in the Abdomen and Pelvis.

Human cancers are genetically complex and diverse. Although advances in oncologic therapy aim to define and target unique steps in carcinogenesis, oncologists often rely on less discriminate anticancer therapies that have consequences for normal tissues. Even many of the so-called targeted therapies currently employed can adversely affect normal cells, leading to complications that necessitate dose reductions or cessation of specific therapies. This article explores the unintended consequences of currently employed systemic and ablative anticancer therapies that might manifest at imaging examinations of the abdomen and pelvis, including cytotoxic, molecular targeted, and immunologic agents; ablation; and hematopoietic stem cell transplant. Each of these treatments can have both major and minor unintended effects in the targeted organ(s), in local or adjacent structures, or at distant sites. Timely detection and reporting of adverse consequences of anticancer therapies by the astute imager can result in critical treatment modifications and/or lifesaving interventions; therefore, knowledge of these unintended effects is paramount for radiologists interpreting the results of imaging examinations in cancer patients. ©RSNA, 2018.

Phantom Validation of Spectral Detector Computed Tomography-Derived Virtual Monoenergetic, Virtual Noncontrast, and Iodine Quantification Images.

PURPOSE: Spectral detector computed tomography (SDCT) is a new CT technology that uses a dual-layer detector to perform energy separation. We aim to assess 3 clinical concepts using a phantom model: noise profile across the virtual monoenergetic (VME) spectrum, accuracy of iodine quantification, and virtual noncontrast (VNC) reconstructions' ability to remove iodine contribution to attenuation. METHODS: Six vials containing varying concentrations of iodinated contrast (0-6 mg/mL) diluted in water were placed in a water bath and scanned on an SDCT scanner. Virtual monoenergetic (40-200 keV at 10-keV increments), iodine-no-water, and VNC reconstructions were created. Attenuation (in Hounsfield units [HU]), VME noise at each energy level, CT-derived iodine concentration, and VNC attenuation were recorded. RESULTS: Virtual monoenergetic noise was improved at all energies compared with conventional images (conventional, 9.8-11.2; VME, 7.5-9.5). Noise profile showed a slightly higher image noise at 40 keV, but was otherwise relatively flat across the energy spectrum. On iodine-no-water reconstructions, measured varied from actual iodine concentration by ±0.1 mg/mL (SD, 0.16-0.36). Virtual noncontrast attenuation was within 5 HU of water attenuation at all iodine concentrations. CONCLUSION: Reconstructions of SDCT show lower VME image noise, accurate iodine quantification, and VNC attenuation values within 5 HU of expected in a phantom model.

Safety and tolerability of the first-in-class agent CPI-613 in combination with modified FOLFIRINOX in patients with metastatic pancreatic cancer: a single-centre, open-label, dose-escalation, phase 1 trial.

BACKGROUND: Pancreatic cancer statistics are dismal, with a 5-year survival of less than 10%, and more than 50% of patients presenting with metastatic disease. Metabolic reprogramming is an emerging hallmark of pancreatic adenocarcinoma. CPI-613 is a novel anticancer agent that selectively targets the altered form of mitochondrial energy metabolism in tumour cells, causing changes in mitochondrial enzyme activities and redox status that lead to apoptosis, necrosis, and autophagy of tumour cells. We aimed to establish the maximum tolerated dose of CPI-613 when used in combination with modified FOLFIRINOX chemotherapy (comprising oxaliplatin, leucovorin, irinotecan, and fluorouracil) in patients with metastatic pancreatic cancer. METHODS: In this single-centre, open-label, dose-escalation phase 1 trial, we recruited adult patients (aged ≥18 years) with newly diagnosed metastatic pancreatic adenocarcinoma from the Comprehensive Cancer Center of Wake Forest Baptist Medical Center (Winston-Salem, NC, USA). Patients had good bone marrow, liver and kidney function, and good performance status (Eastern Cooperative Oncology Group [ECOG] performance status 0-1). We studied CPI-613 in combination with modified FOLFIRINOX (oxaliplatin at 65 mg/m2, leucovorin at 400 mg/m2, irinotecan at 140 mg/m2, and fluorouracil 400 mg/m2 bolus followed by 2400 mg/m2 over 46 h). We applied a two-stage dose-escalation scheme (single patient and traditional 3+3 design). In the single-patient stage, one patient was accrued per dose level. The starting dose of CPI-613 was 500 mg/m2 per day; the dose level was then escalated by doubling the previous dose if there were no adverse events worse than grade 2 within 4 weeks attributed as probably or definitely related to CPI-613. The traditional 3+3 dose-escalation stage was triggered if toxic effects attributed as probably or definitely related to CPI-613 were grade 2 or worse. The dose level for CPI-613 for the first cohort in the traditional dose-escalation stage was the same as that used in the last cohort of the single-patient dose-escalation stage. The primary objective was to establish the maximum tolerated dose of CPI-613 (as assessed by dose-limiting toxicities). This trial is registered with ClinicalTrials.gov, number NCT01835041, and is closed to recruitment. FINDINGS: Between April 22, 2013, and Jan 8, 2016, we enrolled 20 patients. The maximum tolerated dose of CPI-613 was 500 mg/m2. The median number of treatment cycles given at the maximum tolerated dose was 11 (IQR 4-19). Median follow-up of the 18 patients treated at the maximum tolerated dose was 378 days (IQR 250-602). Two patients enrolled at a higher dose of 1000 mg/m2, and both had a dose-limiting toxicity. Two unexpected serious adverse events occurred, both for the first patient enrolled. Expected serious adverse events were: thrombocytopenia, anaemia, and lymphopenia (all for patient number 2; anaemia and lymphopenia were dose-limiting toxicities); hyperglycaemia (in patient number 7); hypokalaemia, hypoalbuminaemia, and sepsis (patient number 11); and neutropenia (patient number 20). No deaths due to adverse events were reported. For the 18 patients given the maximum tolerated dose, the most common grade 3-4 non-haematological adverse events were hyperglycaemia (ten [55%] patients), hypokalaemia (six [33%]), peripheral sensory neuropathy (five [28%]), diarrhoea (five [28%]), and abdominal pain (four [22%]). The most common grade 3-4 haematological adverse events were neutropenia (five [28%] of 18 patients), lymphopenia (five [28%]), anaemia (four [22%], and thrombocytopenia in three [17%]). Sensory neuropathy (all grade 1-3) was recorded in 17 (94%) of the 18 patients and was managed with dose de-escalation or discontinuation per standard of care. No patients died while on active treatment; 11 study participants died, with cause of death as terminal pancreatic cancer. Of the 18 patients given the maximum tolerated dose, 11 (61%) achieved an objective (complete or partial) response. INTERPRETATION: A maximum tolerated dose of CPI-613 was established at 500 mg/m2 when used in combination with modified FOLFIRINOX in patients with metastatic pancreatic cancer. The findings of clinical activity will require validation in a phase 2 trial. FUNDING: Comprehensive Cancer Center of Wake Forest Baptist Medical Center.

Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging to Identify Clear Cell Renal Cell Carcinoma in cT1a Renal Masses.

PURPOSE: The detection of small renal masses is increasing with the use of cross-sectional imaging, although many incidental lesions have negligible metastatic potential. Among malignant masses clear cell renal cell carcinoma is the most prevalent and aggressive subtype. A method to identify such histology would aid in risk stratification. Our goal was to evaluate a likelihood scale for multiparametric magnetic resonance imaging in the diagnosis of clear cell histology. MATERIALS AND METHODS: We retrospectively reviewed the records of patients with cT1a masses who underwent magnetic resonance imaging and partial or radical nephrectomy from December 2011 to July 2015. Seven radiologists with different levels of experience who were blinded to final pathology findings independently reviewed studies based on a predefined algorithm. They applied a clear cell likelihood score, including 1-definitely not, 2-probably not, 3-equivocal, 4-probably and 5-definitely. Binary classification was used to determine the accuracy of clear cell vs all other histologies. Interobserver agreement was calculated with the weighted κ statistic. RESULTS: A total of 110 patients with 121 masses were identified. Mean tumor size was 2.4 cm and 50% of the lesions were clear cell. Defining clear cell as scores of 4 or greater demonstrated 78% sensitivity and 80% specificity while scores of 3 or greater showed 95% sensitivity and 58% specificity. Interobserver agreement was moderate to good with a mean κ of 0.53. CONCLUSIONS: A clear cell likelihood score used with magnetic resonance imaging can reasonably identify clear cell histology in small renal masses and may decrease the number of diagnostic renal mass biopsies. Standardization of imaging protocols and reporting criteria is needed to improve interobserver reliability.

Circumportal pancreas: imaging findings in 40 patients.

PURPOSE: To analyze the CT and MR imaging features of circumportal pancreas (CP) with emphasis on the relative frequency of variants of parenchymal fusion, ductal anatomy, and vascular anatomy. METHODS: A retrospective review of CT and MR imaging findings of 40 patients with CP was performed. CT and MR images were reviewed by two radiologists in consensus. The course of the pancreatic duct in relation to the portal vein (anteportal vs. retroportal), location of the circumvenous pancreatic parenchyma in relation to the splenic vein (suprasplenic vs. infrasplenic), presence or absence of a visible accessory duct posterior to the portal vein, presence of vascular variants, history of pancreatitis and pancreatic surgery were recorded. Cases were classified into four categories: anteportal suprasplenic, retroportal suprasplenic, anteportal infrasplenic, and retroportal infrasplenic. RESULTS: One case of suprasplenic fusion was excluded from the classification due to non-visualization of the pancreatic duct. 32/39(82%) of cases were classified as anteportal suprasplenic, 2/39(5%) as retroportal suprasplenic, 4/39(10%) as anteportal infrasplenic, and 1/39(3%) as retroportal infrasplenic. There were 12 vascular variants including nine with an intraparenchymal course (through the pancreatic head) of the common hepatic artery, one with an intraparenchymal course of the right hepatic artery, two replaced right hepatic arteries from the superior mesenteric artery, and one with an intraparenchymal course of the left gastric vein. CONCLUSION: Circumportal pancreas is an important pancreatic fusion anomaly with distinctive imaging features. The most common variant of CP is the anteportal suprasplenic subtype, with other subtypes being much less common. Intraparenchymal course of the common hepatic artery is a common variant associated with CP. Recognition of CP is important to avoid potential complications in patients who undergo pancreatic surgery.

Gastroduodenal ulcers on CT: forgotten, but not gone.

OBJECTIVE: To estimate the incidence of missed gastroduodenal ulcers on routine abdominal computed tomography (CT) and identify findings and methods to improve sensitivity of CT interpretation for peptic ulcers. MATERIALS AND METHODS: This is a retrospective chart and imaging review. Two blinded readers independently reviewed CTs performed within 7 days prior to endoscopy of 114 subjects; this included 57 consecutive subjects with proven gastroduodenal ulcers intermixed with 57 subjects with endoscopically normal examinations. Presence, location and size of ulcer crater, and ancillary findings (mural edema, asymmetric wall thickening, focal fat stranding, regional lymph nodes, and extraluminal gas) were recorded before and after review of multiplanar reformatted images. Radiology reports were then reviewed to determine if an ulcer was identified prospectively. RESULTS: Thirty-one ulcers (54%) were radiographically occult, missed by both readers. Thirteen ulcers were correctly and independently identified by both readers (sensitivity/specificity = 30%/100%). With review of multiplanar reformats, sensitivity and accuracy increased for both readers. When two or more ancillary findings were identified, the odds ratio of a true ulcer being present was greater than 5.6 (P = 0.0001). Both size and location of ulcer were important for detection; readers were more likely to identify gastric ulcers compared to duodenal or marginal ulcers (P = 0.02). Only 3/13 definitely visible ulcers were correctly identified during initial CT interpretation. CONCLUSIONS: Although CT has low sensitivity for peptic ulcer disease, the miss rate for visible peptic ulcers is high. Increased awareness, multiplanar imaging review, and identification of ancillary findings may improve sensitivity for gastroduodenal ulcers.

Practical approach to MRI of female pelvic masses.

OBJECTIVE: Female pelvic masses have a broad differential diagnosis, including benign and malignant neoplasms and nonneoplastic entities. CONCLUSION: By using a systematic approach to the evaluation of a complex pelvic mass, including incorporating the clinical and surgical history, and by using multiparametric MRI to identify the anatomic origin, morphologic features, and tissue composition of a mass, a short meaningful differential diagnosis or definitive diagnosis can often be established.

In-phase signal intensity loss in solid renal masses on dual-echo gradient-echo MRI: association with malignancy and pathologic classification.

OBJECTIVE: The purposes of this study were to determine the prevalence of in-phase signal intensity loss on dual-echo gradient-echo MRI in solid renal masses using visual and quantitative techniques and to test for any association between in-phase signal intensity loss and pathologic classification. MATERIALS AND METHODS: The renal MRI studies of 177 patients (192 solid masses consisting of 166 renal cell carcinomas [RCCs], four malignant non-RCCs, and 22 benign tumors) were qualitatively reviewed by two blinded readers for visual evidence of relative in-phase signal intensity loss. For lesions without visual evidence, whole-lesion ROIs were used to attempt quantification of subtle signal intensity loss between opposed- and in-phase images (signal intensity loss index). RESULTS: Visual in-phase signal intensity loss was noted in 18% of clear cell RCC, 42% of papillary RCC, and no benign lesions. There was significant correlation between malignancy and visual signal intensity loss (Fisher exact test, p = 0.0092). Visual signal intensity loss was predictive of papillary RCC over clear cell RCC (odds ratio, 5.79; p = 0.0002) in logistic regression analysis of all RCCs, controlling for size. Quantitative assessment of remaining lesions provided no additional diagnostic benefit. CONCLUSION: Visible in-phase signal intensity loss is relatively common within solid renal masses and was associated with RCC and particularly papillary RCC (among all RCCs) in our population. Quantitative analysis in lesions without visible signal intensity loss was not predictive of RCC. Further work should be performed to validate the usefulness of this additional imaging parameter to help characterize renal masses and to determine the impact of this finding on imaging techniques potentially sensitive to susceptibility effects.

From esophagus to rectum: a comprehensive review of alimentary tract perforations at computed tomography.

Gastrointestinal (GI) tract perforation is a life-threatening condition that can occur at any site along the alimentary tract. Early perforation detection and intervention significantly improves patient outcome. With a high sensitivity for pneumoperitoneum, computed tomography (CT) is widely accepted as the diagnostic modality of choice when a perforated hollow viscus is suspected. While confirming the presence of a perforation is critical, clinical management and surgical technique also depend on localizing the perforation site. CT is accurate in detecting the site of perforation, with segmental bowel wall thickening, focal bowel wall defect, or bubbles of extraluminal gas concentrated in close proximity to the bowel wall shown to be the most specific findings. In this article, we will present the causes for perforation at each site throughout the GI tract and review the patterns that can lead to prospective diagnosis and perforation site localization utilizing CT images of surgically proven cases.

Characterizing solid renal neoplasms with MRI in adults.

Until recently, most solid renal neoplasms without macroscopic fat were presumed to represent renal cell carcinoma and were indiscriminately treated with nephrectomy. Expanding surgical options and ablative technologies, a growing acceptance of renal mass biopsy, the advent of targeted molecular agents, and advances in our understanding of tumor biology have challenged the wisdom of this approach and are ushering in a potential new era in which therapy is linked to histologic subtype and cytogenetics. This approach mandates evolution of our diagnostic algorithm beyond the distinction between solid and cystic and enhancing and nonenhancing. Computed tomography (CT) has traditionally been the imaging technique of choice for evaluating potential solid renal tumors, in large part due to its widespread availability, high spatial resolution, calcium discrimination, and multiphase, enhanced imaging capabilities. For the most part, however, CT is limited to characterization based upon the attenuation and enhancement characteristics of a lesion and necessitates exposure of patients to ionizing radiation. For these latter reasons, multiparametric magnetic resonance imaging (MRI) is being increasingly used to characterize solid renal masses. The purpose of this manuscript is to review our imaging approach to solid renal masses in adults utilizing MRI with an emphasis on a multiparametric approach augmented by clinical data.

Contrast-enhanced magnetic resonance urography at 3T: clinical feasibility.

OBJECTIVE: The objective of this study was to assess the feasibility of performing diagnostic-quality contrast-enhanced excretory magnetic resonance urography (eMRU) at 3T, examining both image quality and diagnostic accuracy for a range of urinary tract abnormalities. METHODS: The diuretic-enhanced 3T eMRUs of 37 patients were reviewed to assess for the diagnostic conspicuity of urinary tract abnormalities, extent of urinary tract visualization on excretory images, and presence and severity of image artifacts. RESULTS: Excretory images allowed greater than 75% visualization in 90.8% of renal collecting systems, 90.8% of ureters, and 82.3% of bladders. Common artifacts included susceptibility (21.3%), contrast mixing (21.3%), patient motion (20.4%), signal inhomogeneity (19.4%), and peristaltic motion (17.6%). Severe artifacts occurred in 21.6% of studies. Five of 8 urothelial neoplasms were detected, with 1 false-positive lesion in the bladder. Urolithiasis was correctly diagnosed in 7 of 9 patients. CONCLUSIONS: Although image artifacts can hamper eMRU at 3T, initial results are promising for evaluation of the urothelium.

Practical Tips and a Template for Developing Your Curriculum Vitae.

The Alliance of Leaders in Academic Affairs in Radiology (ALAAR) advocates for a Universal Curriculum Vitae for all medical institutions and to that end, we have developed a template that can be downloaded on the AUR website (ALAAR CV template) that includes all of the elements required by many academic institutions. Members of ALAAR represent multiple academic institutions and have spent many hours reviewing and providing input on radiologists' curricula vitae. The purpose of this review is to help academic radiologists accurately maintain and optimize their CVs with minimal effort and to clarify common questions that arise at many different institutions in the process of constructing a CV.