Jeanne M. Horowitz

Diffusion-weighted magnetic resonance imaging of pancreatic adenocarcinomas: association with histopathology and tumor grade.

To evaluate the utility of diffusion‐weighted magnetic resonance imaging (DWI) in pancreatic ductal adenocarcinoma with various grades of differentiation.

Accuracy of MR Elastography and Anatomic MR Imaging Features in the Diagnosis of Severe Hepatic Fibrosis and Cirrhosis

To compare the diagnostic accuracy of magnetic resonance imaging elastography (MRE) and anatomic MRI features in the diagnosis of severe hepatic fibrosis and cirrhosis.

Radiologic Assessment of Response to Therapy: Comparison of RECIST Versions 1.1 and 1.0

Improvements in radiologic imaging technology and therapeutic options available for management of tumors have necessitated the revision of guidelines for the imaging-based assessment of tumor response to therapy. The purpose of this article is to familiarize radiologists with the modifications to the Response Evaluation Criteria in Solid Tumors (RECIST) that have been incorporated in the latest version of the guidelines, RECIST 1.1. The most important differences between this version and the previous one, RECIST 1.0, include reductions in the maximum number of lesions per patient and per organ that may be targeted for measurement, augmentation of the criteria defining progressive disease, additional guidelines for reporting findings of lesions that are too small to measure and for measuring lesions that appear to have fragmented or coalesced at follow-up imaging, new criteria for characterizing lymphadenopathy, new criteria for selecting bone lesions and cystic lesions as targets for measurement, and the inclusion of findings at positron emission tomography among the indicators of disease response.

CT and MR Imaging for Evaluation of Cystic Renal Lesions and Diseases

Cystic renal lesions are commonly encountered in abdominal imaging. Although most cystic renal lesions are benign simple cysts, complex renal cysts, infectious cystic renal disease, and multifocal cystic renal disease are also common phenomena. The Bosniak classification system provides a useful means of categorizing cystic renal lesions but places less emphasis on their underlying pathophysiology. Cystic renal diseases can be categorized as focal, multifocal, or infectious lesions. Diseases that manifest with focal lesions, such as cystic renal cell carcinoma, mixed epithelial and stromal tumor, and cystic nephroma, are often difficult to differentiate but have differing implications for follow-up after resection. Multifocal cystic renal lesions can be categorized as acquired or heritable. Acquired entities, such as glomerulocystic kidney disease, lithium-induced nephrotoxicity, acquired cystic kidney disease, multicystic dysplastic kidney, and localized cystic renal disease, often have distinct imaging and clinical features that allow definitive diagnosis. Heritable diseases, such as autosomal dominant polycystic kidney disease, von Hippel-Lindau disease, and tuberous sclerosis, are usually easily identified and have various implications for patient management. Infectious diseases have varied imaging appearances, and the possibility of infection must not be overlooked when assessing a cystic renal lesion. A thorough understanding of the spectrum of cystic renal disease will allow the radiologist to make a more specific diagnosis and provide the clinician with optimal recommendations for further diagnostic testing and follow-up imaging.

CT of the Abdomen with Reduced Tube Voltage in Adults: A Practical Approach

Recent innovations in computed tomographic (CT) hardware and software have allowed implementation of low tube voltage imaging into everyday CT scanning protocols in adults. CT at a low tube voltage setting has many benefits, including (a) radiation dose reduction, which is crucial in young patients and those with chronic medical conditions undergoing serial CT examinations for disease management; and (b) higher contrast enhancement. For the latter, increased attenuation of iodinated contrast material improves the evaluation of hypervascular lesions, vascular structures, intestinal mucosa in patients with bowel disease, and CT urographic images. Additionally, the higher contrast enhancement may provide diagnostic images in patients with renal dysfunction receiving a reduced contrast material load and in patients with suboptimal peripheral intravenous access who require a lower contrast material injection rate. One limitation is that noisier images affect image quality at a low tube voltage setting. The development of denoising algorithms such as iterative reconstruction has made it possible to perform CT at a low tube voltage setting without compromising diagnostic confidence. Other potential pitfalls of low tube voltage CT include (a) photon starvation artifact in larger patients, (b) accentuation of streak artifacts, and (c) alteration of the CT attenuation value, which may affect evaluation of lesions on the basis of conventional enhancement thresholds. CT of the abdomen with a low tube voltage setting is an excellent radiation reduction technique when properly applied to imaging of select patients in the appropriate clinical setting.

Acute Pancreatitis: Revised Atlanta Classification and the Role of Cross-Sectional Imaging

OBJECTIVE The 2012 revision of the Atlanta Classification emphasizes accurate characterization of collections that complicate acute pancreatitis: acute peripancreatic fluid collections, pseudocysts, acute necrotic collections, and walled-off necroses. As a result, the role of imaging in the management of acute pancreatitis has substantially increased. CONCLUSION This article reviews the imaging findings associated with acute pancreatitis and its complications on cross-sectional imaging and discusses the role of imaging in light of this revision.

Imaging Features of Benign and Malignant Ampullary and Periampullary Lesions

The ampulla of Vater is an important anatomic landmark where the common bile duct and main pancreatic duct converge in the major duodenal papilla. Imaging evaluation of the ampulla and periampullary region poses a unique diagnostic challenge to radiologists because of the regions complex and variable anatomy and the variety of lesions that can occur. Lesions intrinsic to the ampulla and involved segment of the biliary tree can be neoplastic, inflammatory, or congenital. Neoplastic lesions include ampullary adenocarcinomas and adenomas, which often are difficult to differentiate, as well as pancreatic or duodenal adenocarcinomas, pancreatic neuroendocrine tumors, and cholangiocarcinomas. Ultrasonography (US), computed tomography, magnetic resonance (MR) imaging, and MR cholangiopancreatography are commonly used to evaluate this region. Endoscopic retrograde cholangiopancreatography or endoscopic US examination may be necessary for more definitive evaluation. Periampullary conditions in the duodenum that may secondarily involve the ampulla include neoplasms, duodenitis, duodenal diverticula, and Brunners gland hyperplasia or hamartomas. Because these lesions can exhibit a wide overlap of imaging features and subtle or nonspecific imaging findings, diagnosis is made on the basis of patient age, clinical history, and imaging and laboratory findings. Given the complexity of imaging evaluation of the ampulla and periampullary region, it is essential for radiologists to understand the variety of lesions that can occur and recognize their imaging characteristics.

Chemical Shift MR Imaging of the Adrenal Gland: Principles, Pitfalls, and Applications

Adrenal lesions are a common imaging finding. The vast majority of adrenal lesions are adenomas, which contain intracytoplasmic (microscopic) fat. It is important to distinguish between adenomas and malignant tumors, and chemical shift magnetic resonance (MR) imaging can be used to accomplish this distinction by depicting the fat in adenomas. Chemical shift imaging is based on the difference in precession frequencies of water and fat molecules, which causes them to be in different relative phases during the acquisition sequence and allows in-phase and opposed-phase images to be obtained. It is important to acquire these images by using the earliest possible echo times, with the opposed-phase echo before the in-phase echo, and by using a single breath hold to preserve diagnostic accuracy. Intracytoplasmic fat is depicted as signal drop on opposed-phase images when compared with in-phase images. Both qualitative and quantitative methods for assessing signal drop are detailed. The appearances of adrenal adenomas and other adrenal tumors on chemical shift MR images are described, and discriminatory ability at chemical shift MR imaging compared with that at adrenal computed tomography (CT) is explained. Other adrenal-related conditions in which chemical shift MR imaging is helpful are also discussed. Chemical shift MR imaging is a robust tool for evaluating adrenal lesions that are indeterminate at nonenhanced CT. However, it is important to know the advantages and disadvantages, including several potential imaging pitfalls. The characterization of adrenal lesions by using chemical shift MR imaging and adrenal CT should always occur in the appropriate clinical setting.

Phase II study of alemtuzumab–rituximab therapy in previously untreated patients with chronic lymphocytic leukemia: short- and long-term outcomes

Abstract We investigated the safety, efficacy, and long-term outcomes of alemtuzumab and rituximab (AR) combination therapy in previously untreated patients with CLL. Thirty patients, ages 28–80 years, 47% older than 60 years, 90% Rai clinical stages II–IV, and 67% without favorable cytogenetics received AR. Based on the NCI-WG 1996 criteria, OR was 100%, with 60% CR. With CT scans OR was 70%, with 23% CR, 47% PR, and 30% SD. Sixty-seven percent of patients showed no evidence of MRD in the bone marrow by 6-color flow cytometry. Median PFS, TFS, and 5-year OS were 24.4, 50.7 months, and 80%, respectively. Grade 3/4 neutropenia and thrombocytopenia were reported in 30% and 7% of patients, respectively. CMV reactivation, asymptomatic in all but one patient, occurred in 8 patients. Immunotherapy with alemtuzumab and rituximab results in robust responses and long asymptomatic therapy-free intervals. It is well tolerated with infrequent, predictable, and easily managed complications.

Will CT Ordering Practices Change if We Educate Residents About the Potential Effects of Radiation Exposure?: Experience at a Large Academic Medical Center

RATIONALE AND OBJECTIVES The aim of this study was to determine if educating residents about the potential effects of radiation exposure from computed tomographic (CT) imaging alters ordering patterns. This study also explored whether referring physicians are interested in radiation education and was an initial effort to address their CT ordering behavior. MATERIALS AND METHODS Two to four months after a radiologists lecture on the potential effects of radiation exposure related to CT scans, urology and orthopedic residents were surveyed regarding the number and types of CT scans they ordered, the use of alternative imaging modalities, and whether they used the lecture information to educate patients. RESULTS Twenty-one resident lecture attendants completed the survey. The number of CT scans ordered after the lecture stayed constant for 90% (19 of 21) and decreased for 10% (two of 21). The types of CT scans ordered changed after the lecture for 14% (three of 21). Thirty-three percent (seven of 21) reported increases in alternative imaging after the lecture, including 24% (five of 21) reporting increases in magnetic resonance imaging and 19% (four of 21) reporting increases in ultrasound. Patients directed questions about radiation exposure to 57% (12 of 21); 38% (eight of 21) used the lecture information to educate patients. Referring physicians were interested in the topic, and afterward, other physician groups requested radiation education lectures. CONCLUSIONS Most clinicians did not change their CT scan ordering after receiving education about radiation from a radiologist. Radiation education allowed clinicians to discuss CT benefits and risks with their patients and to choose appropriate CT protocols. Referring physician groups are interested in this topic, and radiologists should be encouraged to give radiation lectures to them.