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There have been many publications detailing imaging features of malignant transformation of intraductal papillary mucinous neoplasms (IPMN), management and recommendations for imaging follow-up of diagnosed or presumed IPMN. However, there is no consensus on several practical aspects of imaging IPMN that could serve as a clinical guide for radiologists and enable future data mining for research. These aspects include how to measure IPMN, define reporting terminology, standardize reporting and unify guidelines for surveillance. The Society of Abdominal Radiology (SAR) created multiple Disease-Focused Panels (DFP) comprised multidisciplinary panel members who focus on a particular disease, with the goal to develop ways for radiologists to improve patient care, education, and research. DFP members met to identify the current controversies and limitations of imaging pancreatic IPMN. This paper aims to provide a practical review of the key imaging characteristics of IPMN for trainees and practicing radiologists, to guide uniformity of performance and interpretation of surveillance imaging studies, and to improve communication with clinicians by providing a lexicon and reporting template based on the experience of the SAR-DFP panel members.

Background: Objective radiographic assessment is crucial for accurately evaluating therapeutic efficacy and patient outcomes in oncology clinical trials. Imaging assessment workflow can be complex; can vary with institution; may burden medical oncologists, who are often inadequately trained in radiology and response criteria; and can lead to high interobserver variability and investigator bias. This article reviews the development of a tumor response assessment core (TRAC) at a comprehensive cancer center with the goal of providing standardized, objective, unbiased tumor imaging assessments, and highlights the web-based platform and overall workflow. In addition, quantitative response assessments by the medical oncologists, radiologist, and TRAC are compared in a retrospective cohort of patients to determine concordance. Patients and Methods: The TRAC workflow includes an image analyst who pre-reviews scans before review with a board-certified radiologist and then manually uploads annotated data on the proprietary TRAC web portal. Patients previously enrolled in 10 lung cancer clinical trials between January 2005 and December 2015 were identified, and the prospectively collected quantitative response assessments by the medical oncologists were compared with retrospective analysis of the same dataset by a radiologist and TRAC. Results: This study enlisted 49 consecutive patients (53% female) with a median age of 60 years (range, 29–78 years); 2 patients did not meet study criteria and were excluded. A linearly weighted kappa test for concordance for TRAC versus radiologist was substantial at 0.65 (95% CI, 0.46–0.85; standard error [SE], 0.10). The kappa value was moderate at 0.42 (95% CI, 0.20–0.64; SE, 0.11) for TRAC versus oncologists and only fair at 0.34 (95% CI, 0.12–0.55; SE, 0.11) for oncologists versus radiologist. Conclusions: Medical oncologists burdened with the task of tumor measurements in patients on clinical trials may introduce significant variability and investigator bias, with the potential to affect therapeutic response and clinical trial outcomes. Institutional imaging cores may help bridge the gap by providing unbiased and reproducible measurements and enable a leaner workflow.

Rationale and Objectives To evaluate whether a computed tomography (CT)-based computerized decision-support system for muscle-invasive bladder cancer treatment response assessment (CDSS-T) can improve identification of patients who have responded completely to neoadjuvant chemotherapy. Materials and Methods Following Institutional Review Board approval, pre-chemotherapy and post-chemotherapy CT scans of 123 subjects with 157 muscle-invasive bladder cancer foci were collected retrospectively. CT data were analyzed with a CDSS-T that uses a combination of deep-learning convolutional neural network and radiomic features to distinguish muscle-invasive bladder cancers that have fully responded to neoadjuvant treatment from those that have not. Leave-one-case-out cross-validation was used to minimize overfitting. Five attending abdominal radiologists, four diagnostic radiology residents, two attending oncologists, and one attending urologist estimated the likelihood of pathologic T0 disease (complete response) by viewing paired pre/post-treatment CT scans placed side-by-side on an internally-developed graphical user interface. The observers provided an estimate without use of CDSS-T and then were permitted to revise their estimate after a CDSS-T-derived likelihood score was displayed. Observer estimates were analyzed with multi-reader, multi-case receiver operating characteristic methodology. The area under the curve (AUC) and the statistical significance of the difference were estimated. Results The mean AUCs for assessment of pathologic T0 disease were 0.80 for CDSS-T alone, 0.74 for physicians not using CDSS-T, and 0.77 for physicians using CDSS-T. The increase in the physicians' performance was statistically significant (P Conclusion CDSS-T improves physician performance for identifying complete response of muscle-invasive bladder cancer to neoadjuvant chemotherapy.

The aim of the study was to identify the frequency of isolated pelvic metastasis with the goal of determining the utility of pelvic CT as a surveillance strategy in patients with resected biliary tract cancer (BTC). Study eligibility criteria included patients 18 years or older with BTC who underwent R0 or R1 surgical resection at University of Michigan between 2004 and 2018, with a minimum 6-month disease-free surveillance period. CT and MRI reports were independently graded by two radiologists as positive (organ metastasis, peritoneal carcinomatosis, or enlarged lymph nodes), equivocal (borderline lymph nodes or non-nodular ascites), or negative (absence of or benign findings) in the abdomen and pelvis separately. A 3rd blinded radiologist reviewed all positive and equivocal scans. Clinic notes were reviewed to identify new or worsening signs and symptoms that would warrant an earlier pelvic surveillance scan. A 95% binomial proportion confidence interval was used to find the probability of isolated pelvic metastasis. BTC were anatomically classified as extra-hepatic (distal and hilar) cholangiocarcinoma (38; 25%), intra-hepatic cholangiocarcinoma (57; 38%), and gallbladder cancer (56; 37%). 151 patients met eligibility criteria, of which 123 (81%) had no pelvic metastasis, 51 (34%) had localized upper abdominal metastasis, and 23 (15%) had concomitant abdominal and pelvic metastasis. Median follow-up time was 19.2 months. One (0%) subject with resected BTC (intra-hepatic) developed isolated osseous pelvic metastasis during surveillance (95% CI 0.004–0.1; p = 0.0003). 3 (2%) subjects developed isolated simple ascites (equivocal grade) without concurrent upper abdominal metastasis. Isolated pelvic metastasis is a rare occurrence during surveillance in patients with resected BTCs, and therefore, follow-up pelvic CT in absence of specific symptoms may be unnecessary.

We evaluated whether a computerized decision support system for bladder cancer treatment response assessment (CDSS-T) can assist physicians from different institutions in identifying patients who have complete response after neoadjuvant chemotherapy. Pre- and post-chemotherapy CTU scans of 96 patients (114 pre- and post-treatment lesion pairs) were collected retrospectively. The pathological cancer stage after treatment was collected as the reference standard of response to treatment. 24% of the lesion pairs had T0 cancer stage (complete response) after chemotherapy. Our CDSST that combined DL-CNN and radiomics features was trained to distinguish between T0 and

We evaluated the intraobserver variability of physicians aided by a computerized decision-support system for treatment response assessment (CDSS-T) to identify patients who show complete response to neoadjuvant chemotherapy for bladder cancer, and the effects of the intraobserver variability on physicians' assessment accuracy. A CDSS-T tool was developed that uses a combination of deep learning neural network and radiomic features from computed tomography (CT) scans to detect bladder cancers that have fully responded to neoadjuvant treatment. Pre- and postchemotherapy CT scans of 157 bladder cancers from 123 patients were collected. In a multireader, multicase observer study, physician-observers estimated the likelihood of pathologic T0 disease by viewing paired pre/posttreatment CT scans placed side by side on an in-house-developed graphical user interface. Five abdominal radiologists, 4 diagnostic radiology residents, 2 oncologists, and 1 urologist participated as observers. They first provided an estimate without CDSS-T and then with CDSS-T. A subset of cases was evaluated twice to study the intraobserver variability and its effects on observer consistency. The mean areas under the curves for assessment of pathologic T0 disease were 0.85 for CDSS-T alone, 0.76 for physicians without CDSS-T and improved to 0.80 for physicians with CDSS-T (P = .001) in the original evaluation, and 0.78 for physicians without CDSS-T and improved to 0.81 for physicians with CDSS-T (P = .010) in the repeated evaluation. The intraobserver variability was significantly reduced with CDSS-T (P &lt, 0001). The CDSS-T can significantly reduce physicians' variability and improve their accuracy for identifying complete response of muscle-invasive bladder cancer to neoadjuvant chemotherapy.

Topical tissue sealants and hemostatic agents, seen on postoperative imaging in a variety of intraabdominal and pelvic locations, have the potential to be mistaken for abdominal abnormalities, especially if the radiologist is not aware of the patient's surgical history. The normal appearance of these agents may mimic abscesses, tumors, enlarged lymph nodes, or retained foreign bodies. Therefore, it is important to be familiar with their typical imaging appearances and to review the surgical records when needed to avoid misdiagnoses. The purpose of this article is to increase the radiologist's familiarity with various types of topical tissue sealants and hemostatic agents used during surgical and percutaneous procedures in the abdomen and pelvis along with their radiologic appearances.Various types of hemostatic agents are now commonly used during surgery and percutaneous procedures in the abdomen and pelvis, and it is important to recognize the various appearances of these agents. Although there are suggestive features outlined in this article, the most important factor for the radiologist is to be aware of the patient's history and the possibility that a hemostatic agent may be present. On postoperative imaging, hemostatic agents may mimic abscesses, tumors, enlarged lymph nodes, or retained foreign bodies, and accurate diagnosis can save a patient unnecessary treatment. It is therefore crucial to incorporate knowledge of the patient's surgical history with recognition of the typical imaging appearances of hemostatic agents and other pseudolesions to avoid misdiagnoses.

OBJECTIVE. The purposes of this study were to investigate factors driving callback MRI and CT examinations and to discern opportunities for optimizing the patient experience by reducing future call...

The purpose of this study was to determine whether routine pelvic imaging is necessary during postoperative surveillance of pathologic T2-T4 renal cell carcinoma after nephrectomy for curative intent.A retrospective single-institution cohort study with 603 subjects undergoing partial or radical nephrectomy of T2-T4 renal cell carcinoma with curative intent was conducted from January 1, 2000, through December 31, 2015. Clinical and imaging (CT or MRI) follow-up findings were evaluated in a prospectively maintained registry to determine the timing and location of recurrent and metastatic disease. The primary outcome was the proportion of subjects with positive or equivocal findings in the pelvis and negative findings in the chest and abdomen. Binomial CIs were calculated and compared with a prespecified minimum detection threshold of 5%.The T category distribution was as follows: T2 (28.9% [174/603]), T3 (70.3% [424/603]), and T4 (0.8% [5/603]). Most (81.8% [493/603]) of the patients underwent radical nephrectomy, and 27.0% (163/603) had recurrence or metastasis (mean time to first recurrence, 600 ± 695 days). Pelvic imaging findings were negative in 97.0% (585/603) of cases. Four subjects (0.7% [95% CI, 0.2-1.7%]) had isolated positive findings in the pelvis (p0.0001 vs the 5% threshold). Two (0.3% overall [95% CI, 0.04-1.1%]) of these positive findings were in subjects who did not have symptoms.Routine pelvic imaging of patients undergoing surveillance for asymptomatic T2-T4 renal cell carcinoma after nephrectomy performed with curative intent has minimal value and probably should not be performed.

To assess the frequency with which previously reported characteristic findings of retroperitoneal fibrosis (RPF) (a circumferential or almost circumferential peri-aortic mass centered at L4, which does not displace the abdominal aorta or proximal common iliac arteries) are present in patients with RPF, in patients with other fibrosing diseases, and in cancer patients referred to a subspecialty clinic with a suspected diagnosis of RPF, in order to determine whether diagnostic percutaneous biopsy can be avoided in some patients. This HIPAA-compliant Institutional Review Board-approved retrospective study assessed clinical and CT and MR imaging abnormalities on imaging studies in 92 patients referred to a subspecialty clinic with suspected RPF over a 14-year period. Two reviewers, in consensus, determined the frequency of different CT and MRI findings in three groups of patients (Group 1: those with an eventual diagnosis of RPF, Group 2: those with a fibrosing disease associated with vascular or urologic abnormalities, and Group 3: those with cancer). Assessed imaging features included the presence of retroperitoneal masses, whether masses were single or multiple, whether such masses were circumferential or nearly circumferential, whether they displaced the aorta away from the spine (with the degree of such displacement measured), and whether there were abnormalities outside of the peri-aortic region of the retroperitoneum. The frequency with which findings previously reported as characteristic of RPF were present was determined for each of the three groups. Imaging results were correlated with the final diagnoses. Of 68 subjects eventually diagnosed with retroperitoneal fibrosis (RPF) (Group 1), 47 had peri-aortic retroperitoneal masses, 18 of which displaced the aorta anteriorly away from the spine. Of 12 subjects with fibrosing abnormalities related to vascular or urologic disease (Group 2), six had retroperitoneal masses, none of which displaced the aorta away from the spine. Of 12 subjects with malignancies (Group 3), six had peri-aortic retroperitoneal masses only two of whom had aortic displacement. Only 34 of 68 Group 1 subjects had peri-aortic masses characteristic of RPF, compared with six Group 2 subjects and one Group 3 subject. Subjects with characteristic retroperitoneal masses were significantly more likely to have benign disease than cancer (p = 0.009). Many patients with RPF do not have characteristic imaging findings. Contrary to prior publications, absence of aortic displacement is not seen in all patients with RPF and is seen in some cancer patients. Nonetheless, when infiltrative peri-aortic retroperitoneal soft tissue that does not displace the aorta is encountered on CT or MRI, RPF can be diagnosed with a high degree of confidence, obviating the need for biopsy.

PurposeThe purpose of this study was to determine the frequency in which the pelvis component of an abdominopelvic CT provides information that would influence clinical management in two separate groups of patients: those with previously resected pancreatic ductal adenocarcinoma (PDA) and those with locally advanced unresectable PDA.MethodsThis institutional review-board approved HIPAA compliant retrospective study with waived informed consent included 247 subjects with histologically proven PDA, including 153 subjects post-pancreaticoduodenectomy and 94 subjects with locally advanced unresectable disease. Imaging reports interpreted between January 2005 and December 2013 were obtained from our institution's Radiology Information System by searching a Cancer Registry database of PDA patients separately for the words "whipple" and "unresectable." CT findings were separated by location in the abdomen or pelvis, and subsequently reviewed and graded for their likelihood of representing metastatic disease. The probability of pelvic CT influencing clinical management-i.e., of finding isolated pelvic metastatic disease-was determined using 95% binomial proportion confidence intervals for both the post-pancreaticoduodenectomy and locally advanced unresectable groups.ResultsNo subjects who had undergone pancreaticoduodenectomy had an isolated pelvic metastasis on follow-up imaging (0%; 95% CI 0-2.38, p=0.0004); 33 had metastatic disease in the abdomen, and 120 had no or equivocal evidence of abdominopelvic metastatic disease. One subject with locally advanced unresectable PDA had a possible isolated pelvic metastasis on follow-up imaging (1.1%; 95% CI 0.03-5.79, p=0.048); 20 had metastatic disease in the abdomen, and 73 had no or equivocal evidence of abdominopelvic metastatic disease.ConclusionIsolated pelvic metastatic disease rarely occurs in patients with PDA who have had prior pancreaticoduodenectomy or have a locally advanced unresectable primary tumor, suggesting routine pelvic CT in follow-up imaging of these patients may not be necessary.

Imaging plays a central role in the management of patients with suspected or known periampullary masses, including the initial diagnosis, staging, and follow-up to assess treatment response or recurrence. Use of appropriate imaging tools, application of optimal imaging protocols, and knowledge about imaging findings are essential for the diagnosis and accurate staging of these masses. Structured reporting of the imaging studies offers several advantages over freestyle dictations ensuring completeness of the relevant imaging findings, which would in turn help in deciding the best individual treatment strategy for each patient.

Response Evaluation Criteria in Solid Tumors (RECIST), including version 1.0 and 1.1, has been universally accepted as the standard response assessment criteria for conventional chemotherapies. Increasing use of immunotherapy led to the need and development of immune-related RECIST. Imaging plays a crucial role in response assessment for solid tumors in guiding patient management as well as in clinical trials. Familiarity to different response criteria will help radiologists to optimally identify, select, and measure tumor lesions per the criteria and assess response to therapy. This article provides a comprehensive review of published RECIST criteria.

Introduction The use of multidetector computed tomography (CT) and magnetic resonance imaging (MRI) with imaging protocols optimized for imaging of the pancreas has improved the localization as well as the detection and the characterization of pancreatic lesions. Although the typical radiological appearances of common pancreatic lesions is well known, there are several potential pitfalls that can be encountered in pancreatic imaging, such as pancreatic anatomical variants mimicking pancreatic lesions, inflammatory conditions mimicking malignancy, atypical radiological appearance of pancreatic adenocarcinoma, and cystic pancreatic lesions and peripancreatic lesions mimicking intrapancreatic lesions. An understanding of these potential pitfalls in pancreatic imaging is essential to avoid misdiagnosis that can result in inappropriate patient management.

High-resolution imaging modalities, such as multi-detector computed tomography, MR imaging, and endoscopic ultrasound, are frequently used alone or in combination to characterize focal solid and cystic pancreatic neoplasms. Imaging in solid pancreatic neoplasms, typically adenocarcinoma and neuroendocrine tumors, is primarily used to detect and stage the extent of the tumor and to determine if complete surgical resection for cure is feasible. In cystic pancreatic masses, imaging aims to differentiate benign nonmucinous cystic lesions from potentially or frankly malignant mucin-producing cysts. Several noninvasive and invasive treatment options can be performed if surgical resection is not possible or contraindicated.

Small bowel obstruction (SBO) accounts for a considerable proportion of emergency room visits, inpatient admissions, and surgical interventions in the United States. Multi-detector computed tomography (MDCT) plays a key role in imaging patients presenting with acute symptoms suggestive of SBO, which helps in establishing the diagnosis, elucidating the cause of obstruction, and detecting complications, such as ischemia or frank bowel necrosis and perforation. Recently, management of patients with SBO has shifted toward a more conservative approach with supportive care and nasogastric tube decompression, as the obstruction in many cases can resolve spontaneously without the need for operative intervention. However, management decisions in SBO remain notoriously difficult, relying on a combination of clinical, laboratory, and imaging factors to help stratify patients into conservative or surgical treatment. Imaging is often an important factor assisting in the decision-making process since traditional clinical signs of vascular compromise, such as acidosis, fever, leukocytosis, and tachycardia are often unreliable in predicting the need for operative intervention. Thus, it is critically important for radiologists to identify imaging features that suggest or indicated high likelihood of bowel vascular compromise in order to help optimize management prior to the development of bowel ischemia and eventually necrosis. By excluding signs of potentially ischemic or necrotic bowel on MDCT, patients may be spared unnecessary surgery, thus decreasing postsurgical complications and averting potential increase for the risk of future SBO and repeated surgery. Conversely, if imaging features indicate potential vascular compromise of the bowel wall that may lead to bowel ischemia, urgent surgical intervention may prevent progression to bowel necrosis and subsequent perforation.

Radiology reports are vital for patient care as referring physicians depend upon them for deciding appropriate patient management. Traditional narrative reports are associated with excessive variability in the language, length, and style, which can minimize report clarity and make it difficult for referring clinicians to identify key information needed for patient care. Structured reporting has been advocated as a potential solution for improving the quality of radiology reports. The Association of University Radiologists-Radiology Research Alliance Structured Reporting Task Force convened to explore the current and future role of structured reporting in radiology and summarized its finding in this article. We review the advantages and disadvantages of structured radiology reports and discuss the current prevailing sentiments among radiologists regarding structured reports. We also discuss the obstacles to the use of structured reports and highlight ways to overcome some of those challenges. We also discuss the future directions in radiology reporting in the era of personalized medicine.

OBJECTIVE. The purpose of this article is to evaluate single-source dual-energy CT (DECT) for distinguishing benign and indeterminate adrenal nodules, with attention to the effects of phase of IV contrast enhancement. MATERIALS AND METHODS. A retrospective review revealed 273 contrast-enhanced abdominal DECT examinations from November 2009 through March 2012. Fifty adrenal nodules 0.8 cm or larger were identified in 41 patients (22 women and 19 men; average age, 66 years; age range, 36–88 years). CT postprocessing and measurements were independently performed by two radiologists (readers 1 and 2) for each nodule, as follows: attenuation (in Hounsfield units) on true unenhanced images; contrast-enhanced attenuation (in Hounsfield units) on monochromatic spectral images at 40, 75, and 140 keV; and contrast-enhanced material density (in milligrams per milliliter) on virtual unenhanced images. Nodules were classified as benign (< 10 HU) and indeterminate (≥ 10 HU) according to true unenhanced images. RESULTS....

To determine whether the frequency of intra-observer measurement discrepancies ≥5 mm for solid renal masses varies by renal mass characteristics and CT contrast phase.This HIPAA-compliant retrospective study was approved by our IRB. We selected single CT images performed during the nephrographic phase (NP) of renal enhancement in 97 patients, each with a single solid renal mass. Mass location, margin, heterogeneity, and growth pattern were assessed. Six readers measured each mass on two occasions3 weeks apart. Readers also measured the masses on images in 50 patients who had corticomedullary phase (CMP) images obtained during the same study. Results were assessed using Chi-square/Fisher's exact and Wilcoxon Signed Rank tests, and logistic regression analyses.For NP to NP comparisons, intra-reader measurement differences ≥5 mm were seen for 3.7% (17/463) of masses4 cm, but increased to 16.8% (20/119) for masses4 cm (p0.0001). Masses with poorly defined margins (15.9% [22/138] vs. 3.4% [15/444] for well-defined margins, p0.0001) and heterogeneity (15.3% [22/144], vs. 5.0% [14/282] for minimally heterogeneous, vs. 0.6% [1/156] for homogeneous, p0.0001), were more frequently associated with measurement differences ≥5 mm. Differences ≥5 mm were more frequent when only CMP images were utilized (14% [42/299]), or when CMP images were compared with NP images (26% [77/299]).A ≥5 mm intra-reader variation in measured size of solid renal masses4 cm is uncommon for NP to NP comparisons. Variation increases when masses are ≥4 cm, poorly defined, or heterogeneous; or when CMP images are utilized.

Splenic lesions are often incidentally detected on abdominal-computed tomography (CT), ultrasound, or magnetic resonance imaging (MRI), and these can pose a diagnostic challenge in patients with suspected or known malignancy. This review will discuss the multimodality imaging features of various benign and malignant splenic pathologies including trauma, infection, infarct, granulomatous disease, benign neoplasms such as hemangioma, hamartoma, and littoral cell angioma, cystic entities such as peliosis, splenic cysts, and pseudocysts, and malignant processes such as metastasis, lymphoma, angiosarcoma, and leiomyosarcoma. While several of these splenic pathologies have characteristic imaging features that are helpful in diagnosis, others have nonspecific findings. In such clinical dilemmas, image-guided intervention may be essential, and we therefore discuss the role of non-vascular, image-guided splenic interventions for diagnostic and therapeutic purposes. The radiologist can play a key part in the clinical diagnosis and management of splenic lesions, and therefore a thorough knowledge of the imaging features of splenic lesions and a thoughtful approach to their management is crucial.

Pancreatic ductal adenocarcinoma is an aggressive malignancy with a high mortality rate. Proper determination of the extent of disease on imaging studies at the time of staging is one of the most important steps in optimal patient management. Given the variability in expertise and definition of disease extent among different practitioners as well as frequent lack of complete reporting of pertinent imaging findings at radiologic examinations, adoption of a standardized template for radiology reporting, using universally accepted and agreed on terminology for solid pancreatic neoplasms, is needed. A consensus statement describing a standardized reporting template authored by a multi-institutional group of experts in pancreatic ductal adenocarcinoma that included radiologists, gastroenterologists, and hepatopancreatobiliary surgeons was developed under the joint sponsorship of the Society of Abdominal Radiologists and the American Pancreatic Association. Adoption of this standardized imaging reporting template should improve the decision-making process for the management of patients with pancreatic ductal adenocarcinoma by providing a complete, pertinent, and accurate reporting of disease staging to optimize treatment recommendations that can be offered to the patient. Standardization can also help to facilitate research and clinical trial design by using appropriate and consistent staging by means of resectability status, thus allowing for comparison of results among different institutions.

Oncocytic adrenal neoplasms (OANs) are rare, but are an important subtype of adrenal tumors that is being diagnosed with increasing frequency. Unfortunately, the imaging characteristics of this tumor have not been well described. Our purpose was to identify CT features to differentiate OANs from adrenocortical carcinomas (ACC). From 1991 to 2012, 18 patients with OANs were identified from our institution’s pathology database. Twelve had CT examinations available for review. CT characteristics of five benign and seven malignant OANs were reviewed by two abdominal radiologists, and compared to ACC (n = 10). Morphologic characteristics and density measurements were recorded for each imaging phase. Absolute contrast washout was calculated and compared. Benign OANs were smaller [mean size 3.7 cm (range 2.6–5.3)] and more homogeneous than malignant OANs and demonstrated greater washout [mean washout percentage 72.3% (range 61–88)]. Malignant OANs demonstrated features similar to ACCs, including size [mean 9.4 cm (range 5.2–9.8)] and internal necrosis (n = 6). Mean enhancement washout percentage for malignant OANs was 12% (range −8 to 32). Benign OANs (oncocytomas) may be distinguished from lipid-rich adenomas on non-contrast CT but may be indistinguishable from lipid-poor adenomas. Malignant oncocytic neoplasms can demonstrate features similar to ACCs, including larger size, internal necrosis, and lower percentage enhancement washout.

In addition to clinical history and evaluations, the results of laboratory tests and imaging studies help clinicians in determining treatment strategies. Imaging plays a central role in the management of oncology patients including the initial diagnosis, staging, and follow-up to assess treatment response. Historically, radiologists have relied on free-style dictations to convey the results of imaging findings in radiology reports to referring clinicians. These unstructured free-style dictations can potentially be a source of frustration as the pertinent information needed to guide treatment may be omitted or difficult to extract from the report, thereby limiting its completeness and usefulness. These limitations can be overcome by adopting a structured and reproducible form of reporting imaging studies to help clinicians in deciding the best treatment strategy for each patient. There is a growing need to establish standardized radiology reporting templates for specific disease processes. One such example involves patients with pancreatic ductal adenocarcinoma, as imaging findings determine the treatment arm to which the patient is assigned. In this presentation, we outline a list of essential features that need to be included in a structured report and highlight this with illustrative case examples.

The contribution of immune activation to accelerated HIV-disease progression in older individuals has not been delineated.Prospective multicenter cohort of older (≥45 years) and younger (18-30 years) HIV-infected adults initiating 192 weeks of antiretroviral therapy (ART). Longitudinal models of CD4 cell restoration examined associations with age-group, thymic volume, immune activation, and viral load.Forty-five older and 45 younger adults (median age 50 and 26 years, respectively) were studied. Older patients had fewer naive CD4 cells (P0.001) and higher HLA-DR/CD38 expression on CD4 (P=0.05) and CD8 cells (P=0.07) than younger patients at any time on ART. The rate of naive and total CD4 cell increase was similar between age groups, but older patients had a faster mean rate of B-cell increase (by +0.7 cells/week; P=0.01), to higher counts than healthy controls after 192 weeks (P=0.003). Naive CD4 increases from baseline were associated with immune activation reductions (as declines from baseline of %CD8 cells expressing HLA-DR/CD38; P0.0001), but these increases were attenuated in older patients, or in those with small thymuses. A 15% reduction in activation was associated with naive gains of 29.9 and 6.2 cells/μl in younger, versus older patients, or with gains of 25.7, 23.4, and 2.1 cells/μl in patients with the largest, intermediate, and smallest thymuses, respectively (P0.01 for interactions between activation reduction and age-group or thymic volume).Older patients had significant B-cell expansion, higher levels of immune activation markers, and significantly attenuated naive CD4 cell gains associated with activation reduction.

The differential diagnosis of hypervascular pancreatic lesions is complex, and includes endocrine and exocrine tumors of the pancreas, metastases to the pancreas, and masses, or mass-like lesions, arising from the neurovascular networks traversing the pancreas. In this manuscript, we will discuss salient imaging findings of these masses, pertinent differential diagnoses, as well as review clinical symptomatology that may aid in the diagnosis of some of these lesions.

Renal vein leiomyosarcoma is a rare tumor whose clinical and imaging features can significantly overlap with those of advanced primary renal neoplasms, particularly renal cell carcinoma. IRB approval was obtained for a retrospective review of clinical and imaging information for five patients with the pathologically proven diagnosis of renal vein leiomyosarcoma at two institutions. Among the five patients, two were female and three male; average age 58.6 (range 42-77). Three patients presented with flank or abdominal pain, one with pulmonary embolism, and one with weight loss and fatigue. Mass size ranged from 4 to 10 cm. Four masses were left-sided and one right-sided. Tumors involved and expanded the renal vein in all cases, with tumor extension to the renal hilum in one case, through the renal hilum into renal parenchyma in two cases, and into inferior vena cava in two cases. All masses demonstrated contrast enhancement, which was solely peripheral in one case. In all cases, extrarenal tumor volume was greater than renal parenchymal tumor volume. When renal masses are predominantly or exclusively intravascular, consideration should be given to the diagnosis of renal vein leiomyosarcoma because preoperative biopsy results could significantly alter management.

The purpose of our study was to compare the effects of i.v. iohexol and iopamidol on renal function in outpatients undergoing CT.We performed a prospective, double-blind, randomized clinical trial of 389 adults with low risk for contrast-induced nephropathy, comparing i.v. iohexol with iopamidol (300 mg I/mL). Serum creatinine (SCr) concentration was measured at baseline and 2 and 3 days after contrast administration. A noninferiority analysis was planned to compare the mean maximum SCr change from baseline between subject groups. Contrast-induced nephropathy rates (three definitions) for both contrast agents were compared as a secondary end point.One hundred ninety and 199 subjects received iohexol and iopamidol, respectively. The mean change in SCr from baseline using the maximum day 2 or 3 measurement was 0.07 ± 0.12 mg/dL (95% CI, 0.05-0.09 mg/dL) for the iohexol group and 0.05 ± 0.12 mg/dL (95% CI, 0.03-0.07 mg/dL) for the iopamidol group. The difference between contrast agents with respect to the mean change in SCr from baseline was -0.02 ± 0.12 mg/dL (95% CI, -0.045 to 0.003 mg/dL; p = 0.08). Contrast-induced nephropathy rates were not statistically different using any definition.Although our results were unable to show absolute noninferiority of iohexol compared with iopamidol because of a very small difference in increase in mean SCr from baseline (using a noninferiority margin of 0.04 mg/dL), this difference is likely of minimal or no clinical importance in outpatients undergoing CT with low risk for contrast-induced nephropathy.

Hepatocellular carcinoma is the third most common cause of cancer-related death. In the past few years, staging systems have been developed that enable patients to be stratified into treatment algorithms in a multidisciplinary setting. Several of these treatments involve minimally invasive image-guided therapy that can be performed by radiologists.

OBJECTIVE. The purpose of this article is to describe and illustrate multimodality imaging features of various pathologic abnormalities involving the ureteric wall and periureteric space, with emphasis on the role of cross-sectional imaging. CONCLUSION. Ureteric and periureteric pathologic abnormalities may be identified on imaging studies, and although urothelial neoplasm remains the most concerning ureteric pathologic abnormality, there are several other nonneoplastic entities that may involve the ureter and the periureteric spaces. Knowledge of the spectrum of imaging findings in these entities may help the interpreting radiologist to formulate appropriate differential diagnoses.

Although most cases of acute pancreatitis are uncomplicated and resolve spontaneously, the presence of complications has significant prognostic importance. Necrosis, hemorrhage, and infection convey up to 25%, 52%, and 80% mortality, respectively. Other complications such as pseudocyst formation, pseudoaneurysm formation, or venous thrombosis increase morbidity and mortality to a lesser degree.We review the computed tomographic findings of complications associated with acute pancreatitis with emphasis on their prognostic significance and impact on clinical management.

Obstructive voiding symptoms are most commonly due to prostatic hyperplasia, but other causes include bladder neck contractures, prostatic carcinomas, neurogenic bladder, and urethral stricture. Symptoms include hesitancy, dribbling, decreased force of stream, and postvoid fullness. Imaging is useful in evaluating the presence and degree of hydronephrosis, estimation of renal function, evaluation of the bladder and prostate, and detection of incidental upper tract malignancies or stones. Various modalities have been used for evaluation of the cause of obstruction. Literature on the indications and usefulness of these radiologic studies for obstructive voiding symptoms in different clinical settings is reviewed.

Metastatic disease is the most common malignant liver lesion. The presence of hepatic metastases greatly affects prognosis and therapy, although does not necessarily preclude curative treatment. The accurate detection and characterization of possible hepatic metastases is critical to the workup of patients with known malignancy. Consequently, hepatic imaging for metastatic disease is a common indication for cross-sectional imaging. This article discusses the current status of various hepatic imaging modalities, with particular attention to their role in the diagnostic workup of suspected hepatic metastases.

With the exception of lymphoma involving the spleen, other primary and secondary neoplasms are rare and infrequently encountered. Primary malignant neoplasms involving the spleen are lymphoma and angiosarcoma. Primary benign neoplasms involving the spleen include hemangioma, lymphangioma, littoral cell angioma and splenic cyst and solid lesions such as hamartoma and inflammatory pseudotumor.

Pancreas transplantation has become more commonplace over the past several decades. Consequently, the radiological evaluation of patients with such transplants has also become more common. Radiologists must therefore be familiar with the normal imaging appearances of pancreas transplant grafts as well as a wide variety of transplant-related complications. In this article, we review the cross-sectional imaging appearances of normal pancreas transplant grafts as well as present representative examples of complications associated with the procedure.

Improvements in imaging technology and the expanding use of imaging have led to a rapid increase in the discovery of incidental renal lesions. These can present both the radiologist and the referring clinician with diagnostic dilemmas. This article addresses the most frequently encountered lesions and provides a framework for the diagnostic and management pathways for both solid and cystic lesions.

The objective of our study was to evaluate the frequency, outcome, and appropriateness of treatment of adults with acute allergiclike reactions related to IV-administered nonionic iodinated contrast media.For IV injections of nonionic iodinated contrast media between January 1, 1999, and December 31, 2005, contrast reaction reports and medical records of patients in whom contrast reactions occurred were reviewed. Data collected included patient sex and age, symptoms, reaction manifestations, treatment, and long-term sequelae. The appropriateness and efficacy of patient management were assessed.Allergic-type reactions occurred in 545 (0.6%) of patients injected with nonionic iodinated contrast media: 418 (77%) reactions were mild, 116 (21%) were moderate, and 11 (2%) were severe. Two hundred twenty-one patients (41%) received treatment. The most commonly administered medication was diphenhydramine (145 patients or 27%). Corticosteroids were administered to 17 patients, nebulized albuterol to 16, and epinephrine to 15. Although 99% of the treatments did not result in any complication, three patients may have had short-term sequelae as a result of receiving a nonrecommended treatment.Patients usually do well after developing acute allergiclike reactions to nonionic iodinated contrast media. Fortunately, in our series, this was true even in the rare cases in which the instituted treatment was considered to be inappropriate. Reacting patients rarely develop serious long-term sequelae.

Purpose To show that cystic renal lesions that would otherwise meet criteria for simple cysts can demonstrate perceptible walls or increased wall thickness on MRI, sometimes causing these lesions to be “upgraded.” It was hypothesized that thickening of cyst walls on MRI can be artifactual, due to data truncation, applied filtering, and low signal-to-noise ratio (SNR). Materials and Methods k-Space data for a 4-cm cyst were created in a 40-cm field of view (FOV) (512 × 512 matrix). Additional data sets were created using the central 512 × 256 and 512 × 128 points. Noise was simulated so that the cyst SNR was approximately 7, 14, and 20, respectively. Actual wall thickness was set at 0.25 mm, and cyst:wall signal at 1:4. An inverse two-dimensional (2D) fast Fourier transform (FFT) yielded simulated images. A Fermi filter was applied to reduce ringing. Images/projections were examined for wall thickening. Seven patients with initially thick-walled cysts on fat-saturated spoiled gradient-echo (FS-SPGR) images were scanned with increasing resolution (256 × 128 and 256 × 256; four patients were also scanned with 512 × 512). Average wall thickness at each resolution was compared using a two-tailed paired Student's t-test. Results Simulations showed apparent wall thickening at low resolution, improving with higher resolutions. Low SNR and application of the Fermi filter made it difficult to identify ringing as the cause of this thickening. The simulation results were confirmed on seven patients, whose cyst walls proved to be artifactually thickened (P < 0.01). Conclusion Thickening of cyst walls on MRI can be artifactual. Upon encountering thick-walled cystic renal lesions, high-resolution images can be acquired to exclude apparent thickening. J. Magn. Reson. Imaging 2008;28103–110. © 2008 Wiley-Liss, Inc.

The purpose of our study was to determine the sensitivity of 16-row multi-detector computed tomography urography (CTU) axial, coronal reformatted, and curved-planar reformatted image-types for upper tract urothelial neoplasm detection. Twenty-one CTU examinations were identified that contained one or more pathology-proven upper tract urothelial neoplasms during our study period. Two readers independently reviewed 1.25 and 2.5 mm axial, coronal reformatted, and curved-planar reformatted excretory phase CTU images. Each reader then documented the location and appearance of lesions suspicious for upper tract urothelial neoplasm. These results were correlated with relevant endoscopic/surgical procedure notes as well as pathology results. Reader #1 detected 72%, 63%, 75%, and 72% of the known 32 upper tract urothelial neoplasms using 1.25 mm axial, 2.5 mm axial, coronal reformatted, and curved-planar reformatted image-types, respectively. Reader #2 detected 72% of the known neoplasms using each of the four image-types. No significant difference in sensitivity between image-types was identified. After combining the results for all four image-types, readers #1 and #2 had overall sensitivities of 94% and 91%. Axial, coronal reformatted, and curved-planar reformatted image-types have similar sensitivities for the detection of upper tract urothelial neoplasm in 16-row multi-detector CTU. Reviewing multiple image-types increases the sensitivity of urothelial lesion detection.

Purpose To determine whether individual and regional liver sensitivity to radiation could be assessed by measuring liver perfusion during a course of treatment using dynamic contrast-enhanced computed tomography scanning. Methods and Materials Patients with intrahepatic cancer undergoing conformal radiotherapy underwent dynamic contrast-enhanced computed tomography (to measure perfusion distribution) and an indocyanine extraction study (to measure liver function) before, during, and 1 month after treatment. We hoped to determine whether the residual functioning liver ( i.e. , those regions showing portal vein perfusion) could be used to predict overall liver function after irradiation. Results Radiation doses from 45 to 84 Gy resulted in undetectable regional portal vein perfusion 1 month after treatment. The volume of each liver with undetectable portal vein perfusion ranged from 0 to 39% and depended both on the patient's sensitivity and on dose distribution. There was a significant correlation between indocyanine green clearance and the mean of the estimated portal vein perfusion in the functional liver parenchyma ( p Conclusion This study reveals substantial individual variability in the sensitivity of the liver to irradiation. In addition, these findings suggest that hepatic perfusion imaging may be a marker for liver function and has the potential to be a tool for individualizing therapy.

Purpose To determine a biweekly dose of oxaliplatin for combination with full-dose gemcitabine and concurrent radiation therapy (RT) in pancreatic cancer. Patients and Methods Patients with previously untreated pancreatic cancer received gemcitabine days 1, 8, and 15, and oxaliplatin days 1 and 15, repeated at 28-day intervals. RT (27 Gy in 1.8-Gy fractions) was administered during cycle 1. Dose escalation was guided using the time-to-event continuous reassessment method. Dose levels 1 to 4 included gemcitabine 1 g/m2 intravenously (IV) during 30 minutes and oxaliplatin 40, 55, 70, or 85 mg/m2 IV during 90 minutes, respectively; for dose levels 5 and 6, oxaliplatin dose remained 85 mg/m2 but infusion time for gemcitabine 1 g/m2 was increased to 65 or 100 minutes, respectively. The trial objective was to determine the dose level associated with dose-limiting toxicity (DLT) through cycle 2 in ≤ 20% of patients. Results Forty-four patients were enrolled (median age, 64 years; 27 men, 17 women) with resectable (n = 12), unresectable (n = 29), and metastatic (n = 3) pancreatic cancer. Ten DLTs occurred in nine patients, including grade 4 platelets (n = 4), decline in performance status (n = 2), GI bleeding (n = 2), and GI toxicity (n = 2). The estimated probability of DLT for dose level 3 was .21 (90% posterior probability interval [PI], .12 to .33); for dose level 4, the estimated probability was .24 (90% PI, .14 to .36). Conclusion The addition of oxaliplatin 85 mg/m2 days 1 and 15 to full-dose gemcitabine and radiation therapy was well tolerated. On the basis of these results, a multi-institutional neoadjuvant phase II study in resectable pancreatic cancer is planned.

Pancreatic adenocarcinoma continues to be a leading cause of cancer death in the Western world and is amongst the leading gastrointestinal cancers. The incidence of pancreatic cancer has been stable or slowly rising in the past few decades. Overall the prognosis is poor with 5-year survival rates still under 5%. Therefore early detection and accurate staging of these tumors is crucial for optimal treatment.

Fistula-in-ano describes an abnormal communication between the anal or rectal epithelium and the perianal skin. Patients present with a range of symptoms and findings ranging from intermittent discharge, pain, and swelling, to acute sepsis. Treatment is surgical, but postsurgical recurrence is not uncommon. Recurrence is frequently due to a part of the tract remaining undetected, and thus untreated, at the initial surgery. Radiological investigation aims to demonstrate clinically undetected infection and fistulous tracts in order to assist presurgical planning and ultimately reduce recurrence rates. This article discusses relevant anatomy and fistula pathogenesis, before focusing on the roles and utilization of the two common modalities, anal endosonography (AES) and magnetic resonance imaging (MRI), in the preoperative workup of fistula-in-ano.

We have shown that high dose conformal radiation combined with chemotherapy appears to prolong the survival of patients with unresectable intrahepatic cancers. The ability to safely deliver higher doses is primarily limited by the development of radiation-induced liver disease, characterized by venous occlusion. In this study, we investigated whether portal venous perfusion measured prior to the end of radiation therapy (RT) together with dose could predict liver venous perfusion dysfunction after treatment. Ten patients with unresectable intrahepatic cancer participated in an IRB-approved computer tomography (CT) perfusion study. Hepatic arterial and portal vein perfusion distributions were estimated by using dynamic contrast enhanced CT and the single compartmental model. Scans were obtained at four time points: prior to treatment, after 15 and 30 fractions of 1.5 Gy treatments, and one month following the completion of RT. Multivariant linear regression was used to determine covariances among the first three time point measurements plus dose for prediction of the post RT measurement. The reduction in the regional venous perfusion one month following RT was predicted by the local accumulated dose and the change in the regional venous perfusion after {approx}30 fractions (F=90.6,p

Purpose To assess the effect of diuretic administration on the image quality of excretory magnetic resonance urography (MRU) obtained following intravenous hydration, and to determine whether intravenous hydration alone is sufficient to produce diagnostic quality studies of nondilated upper tracts. Materials and Methods A total of 22 patients with nondilated upper tracts were evaluated with contrast-enhanced MRU. All patients received 250 mL of saline intravenously immediately prior to the examination. A total of 11 patients received 10–20 mg furosemide in addition to saline. Imaging was performed with a three-dimensional (3D) and two-dimensional (2D) breathhold spoiled gradient-echo sequences. Excretory MRU images were acquired five minutes after the administration of 0.1 mmol/kg gadolinium and were independently reviewed by two radiologists, who were blinded to the MRU technique. Readers evaluated the calyces, renal pelvis, and ureters qualitatively for degree of opacification, distention, and artifacts on a four-point scale. Statistical analysis was performed using a permutation test. Results There was no significant disagreement between the two readers (P = 0.14). Furosemide resulted in significant improvement in calyceal and renal pelvis distention (P < 0.005), and significant artifact reduction in all upper tract segments (P < 0.001) compared to the effect of saline alone. Conclusion Intravenous furosemide significantly improves the image quality of excretory MRU studies obtained following intravenous hydration. Intravenous saline alone is insufficient to produce diagnostic quality studies of the non-dilated upper tracts. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc.

OBJECTIVE. The purpose of this study was to determine the sensitivity and accuracy of imaging-guided core biopsy in the diagnosis of pancreatic masses.CONCLUSION. Imaging-guided core biopsy is sensitive, safe, and accurate in the diagnosis of malignant lesions of the pancreas. Benign biopsy findings cannot be used to exclude the presence of a neoplasm, and repetition of a biopsy should be considered if there is high clinical suspicion of malignancy.

This article discusses the computed tomography (CT) and magnetic resonance (MR) scanning techniques used for the detection and staging of renal cell carcinoma and their pitfalls. Comparison between the Robson and recent modifications to the TNM classifications is also addressed. The accuracy of CT and MR in the staging of renal cell carcinoma and the role of positron emission tomography (PET) scanning is outlined and finally the surveillance of patients who have had curative treatment of renal cell carcinoma is briefly addressed.

To assess prospectively the efficacy and safety of postcontrast magnetic resonance (MR) imaging with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) compared with that of precontrast MR imaging in patients who are known to have or are suspected of having liver lesions and who are scheduled for hepatic surgery.Investigational review board approval and written informed consent were obtained. HIPAA went into effect after data collection. A total of 172 patients were enrolled. After precontrast MR imaging, 169 patients (94 men, 75 women; mean age, 61 years; age range, 19-84 years) received an intravenous bolus of 25 micromol/kg Gd-EOB-DTPA and underwent dynamic gradient-recalled-echo and delayed MR imaging 20 minutes after injection. Arterial and portal phase computed tomography (CT) were performed within 6 weeks of MR imaging. The standard of reference was surgery with intraoperative ultrasonography (US) and biopsy and/or pathologic evaluation of resected liver segments and/or 3-month follow-up of nonresected segments if intraoperative US was not available. Three blinded reviewers and unblinded site investigators identified liver lesions on segment maps. The Wilcoxon signed rank test was used to compare differences in per-patient sensitivity of precontrast and postcontrast MR images. Adverse events were recorded, and patient monitoring and laboratory assay were performed at time of injection and up to 24 hours after contrast material administration.At MR imaging, 316 lesions were identified in 131 patients. In 77% (P = .012), 72% (P = .15), and 71% (P = .027) of patients for readers 1, 2, and 3, respectively, more lesions were seen at precontrast and postcontrast MR imaging combined than at precontrast MR imaging alone. Sensitivity values for blinded readings were significantly greater at postcontrast MR imaging than at precontrast MR imaging for two of three blinded readers. For all blinded readers, combined precontrast and postcontrast MR images showed no difference in sensitivity compared with helical CT scans. The use of MR imaging, however, yielded fewer patients with at least one false-positive lesion (37%, 31%, and 34% of patients for readers 1, 2, and 3, respectively) than did helical CT (45%, 36%, and 43% of patients for readers 1, 2, and 3, respectively).Compared with precontrast MR imaging, postcontrast MR imaging with Gd-EOB-DTPA demonstrated improved sensitivity for lesion detection in the majority of blinded readers, with no substantial adverse events.

Clinically silent adrenal masses are discovered incidentally during diagnostic testing or treatment for clinical conditions that are not related to suspicion of adrenal disease; thus, they are commonly referred to as 'incidentalomas'. The widespread use of high-resolution anatomic imaging techniques such as computed tomography (CT) and magnetic resonance (MR) imaging has led to the increased detection of these masses. In many patients without a known extra-adrenal primary malignancy--and even in patients with a primary neoplasm--most adrenal masses ultimately prove to be benign. However, it remains important that these adrenal masses are accurately characterized to exclude the treatable causes of adrenal disease, and also to accurately stage the oncology patient. The purpose of this chapter is to describe the findings and recent advances in non-invasive imaging methods that are now available for the accurate characterization of incidentally detected adrenal masses (i.e. the differentiation of benign from malignant masses). The imaging techniques and the algorithms that are used in our institution for the evaluation of incidentally detected adrenal mass will be described.