Sarah Bastawrous

Newer PET application with an old tracer: role of 18F-NaF skeletal PET/CT in oncologic practice.

The skeleton is one of the most common sites for metastatic disease, particularly from breast and prostate cancer. Bone metastases are associated with considerable morbidity, and accurate imaging of the skeleton is important in determining the appropriate therapeutic plan. Sodium fluoride labeled with fluorine 18 (sodium fluoride F 18 [(18)F-NaF]) is a positron-emitting radiopharmaceutical first introduced several decades ago for skeletal imaging. (18)F-NaF was approved for clinical use as a positron emission tomographic (PET) agent by the U.S. Food and Drug Administration in 1972. The early use of this agent was limited, given the difficulties of imaging its high-energy photons on the available gamma cameras. For skeletal imaging, it was eventually replaced by technetium 99m ((99m)Tc)-labeled agents because of the technical limitations of (18)F-NaF. During the past several years, the widespread availability and implementation of hybrid PET and computed tomographic (CT) dual-modality systems (PET/CT) have encouraged a renewed interest in (18)F-NaF PET/CT for routine clinical use in bone imaging. Because current PET/CT systems offer high sensitivity and spatial resolution, the use of (18)F-NaF has been reevaluated for the detection of malignant and nonmalignant osseous disease. Growing evidence suggests that (18)F-NaF PET/CT provides increased sensitivity and specificity in the detection of bone metastases. Furthermore, the favorable pharmacokinetics of (18)F-NaF, combined with the superior imaging characteristics of PET/CT, supports the routine clinical use of (18)F-NaF PET/CT for oncologic imaging for skeletal metastases. In this article, a review of the indications, imaging appearances, and utility of (18)F-NaF PET/CT in the evaluation of skeletal disease is provided, with an emphasis on oncologic imaging.

Human whole-blood 1H2O longitudinal relaxation with normal and high-relaxivity contrast reagents: Influence of trans-cell-membrane water exchange

Accurate characterization of contrast reagent (CR) longitudinal relaxivity in whole blood is required to predict arterial signal intensity in contrast‐enhanced MR angiography (CE‐MRA). This study measured the longitudinal relaxation rate constants (R1) over a concentration range for non‐protein‐binding and protein‐binding CRs in ex vivo whole blood and plasma at 1.5 and 3.0 Tesla (T) under physiologic arterial conditions.

Hepatobiliary Oncologic Emergencies: Imaging Appearances and Therapeutic Options

During the course of their disease, many patients with cancer may require urgent care related to hepatobiliary disease. Cross-sectional imaging of these patients is usually performed initially, and the radiologist plays a pivotal role in the initial diagnosis. In this article, we discuss the commonly seen hepatobiliary oncologic emergencies, briefly review imaging diagnosis, and discuss in detail the management options for these conditions. The radiologists awareness and prompt diagnosis aid in formulating a management plan to decrease morbidity and mortality in these potentially lethal conditions.

Human whole blood 1H2O transverse relaxation with gadolinium-based contrast reagents: Magnetic susceptibility and transmembrane water exchange: Contrast Reagent Transverse Relaxivities in Whole Blood

To characterize transverse relaxation in oxygenated whole blood with extracellular gadolinium‐based contrast reagents by experiment and simulation.

A Novel Reporting System to Improve Accuracy in Appendicitis Imaging

OBJECTIVE The purpose of this study was to ascertain if standardized radiologic reporting for appendicitis imaging increases diagnostic accuracy. MATERIALS AND METHODS We developed a standardized appendicitis reporting system that includes objective imaging findings common in appendicitis and a certainty score ranging from 1 (definitely not appendicitis) through 5 (definitely appendicitis). Four radiologists retrospectively reviewed the preoperative CT scans of 96 appendectomy patients using our reporting system. The presence of appendicitis-specific imaging findings and certainty scores were compared with final pathology. These comparisons were summarized using odds ratios (ORs) and the AUC. RESULTS The appendix was visualized on CT in 89 patients, of whom 71 (80%) had pathologically proven appendicitis. Imaging findings associated with appendicitis included appendiceal diameter (odds ratio [OR] = 14 [> 10 vs < 6 mm]; p = 0.002), periappendiceal fat stranding (OR = 8.9; p < 0.001), and appendiceal mucosal hyperenhancement (OR = 8.7; p < 0.001). Of 35 patients whose initial clinical findings were reported as indeterminate, 28 (80%) had appendicitis. In this initially indeterminate group, using the standardized reporting system, radiologists assigned higher certainty scores (4 or 5) in 21 of the 28 patients with appendicitis (75%) and lower scores (1 or 2) in five of the seven patients without appendicitis (71%) (AUC = 0.90; p = 0.001). CONCLUSION Standardized reporting and grading of objective imaging findings correlated well with postoperative pathology and may decrease the number of CT findings reported as indeterminate for appendicitis. Prospective evaluation of this reporting system on a cohort of patients with clinically suspected appendicitis is currently under way.

Emergency Presentations of Colorectal Cancer

Many colorectal carcinomas will present emergently with issues such as obstruction, perforation, and bleeding. Emergency surgery is associated with poor short- and long-term outcomes. For abnormality localizing to the colon proximal to the splenic flexure, surgical management with hemicolectomy is often a safe and appropriate approach. Obstructions are more common in the distal colon, however, where there is an evolving spectrum of surgical and nonsurgical options, most notably by the development of endoluminal stents. Perforation and bleeding are managed similarly to benign causes, as malignancy may be only part of a differential diagnosis at the time of an operation.

Management of Acute Contrast Media Reactions: Assessing Preparedness of a Tertiary Care Veterans Affairs Medical Center

THE PROBLEM: HOSPITAL READINESS FOR CONTRAST MEDIA REACTIONS Acute contrast media reactions can range in severity from mild discomfort to life-threatening anaphylaxis. Three percent of all patients receiving intravenous (IV) contrast will experience reactions, although most will not require treatment. Severe, potentially life-threatening reactions occur in about 1 in 2,500 patients [1]. Overall, contrast reactions remain rare, particularly because of the widespread use of nonionic, lowosmolar contrast media. Because of the rarity of adverse reactions to contrast, many radiologists and hospital staff members remain unfamiliar with optimal treatments, appropriate medications, and their respective doses. Additionally, reaction training for nonradiology staff members covering after hours is not well established. Potential errors that commonly occur in the management of contrast reactions are a failure to recognize a contrast reaction; uncertainty regarding how to treat a reaction; failure to administer oxygen promptly; incorrect dosing or administration of epinephrine, atropine, and antihistamines; and an overall lack of advanced preparedness for the possibility of reactions [2,3]. Because of this concern for a lack f preparedness, other radiology epartments have performed local udit studies or surveys, and often any of these management errors re identified [4,5]. In our quality mprovement initiative, we assessed he readiness of our department nd medical center both during and after hours in responding to acute contrast media reactions and identified areas for improvement to ensure proper and efficient treatment should a contrast reaction occur.

Symptomatic Extraperitoneal Bladder Perforation Following Transurethral Bladder Surgery: Imaging with CT Urography

An 80 year-old man presented to his primary care physician with painless gross hematuria. He reported having intermittent episodes of pink urine containing small clots for about three months. He was initially treated with a single course of ciprofloxacin for presumed urinary tract infection. His symptoms did not improve with antibiotic therapy and he was then referred to our institution for a computed tomography (CT) urogram. CT urogram showed a 4 x 3.6 centimeter (cm) infiltrating solid mass along the left lateral posterior wall of the urinary bladder (Figure-1). Tumor also extended along the bladder dome. Prostate enlargement and bladder diverticula were also present. He was referred to the urology service and subsequently underwent transurethral resection of bladder tumor (TURBT) with fulguration. No intraoperative complications were noted and he returned to the recovery room in satisfactory condition on continuous bladder irrigation. Pathologic examination revealed a 5 cm transitional cell carcinoma with high grade growth pattern invading the deep muscular layer. On postoperative day one, the patient reported abdominal pain and general discomfort. Physical exam revealed a grossly distended abdomen which was tender to palpation with positive guarding and decreased bowel sounds. He Symptomatic Extraperitoneal Bladder Perforation Following Transurethral Bladder Surgery: Imaging with CT Urography _______________________________________________

Human whole blood 1H2O transverse relaxation with gadolinium-based contrast reagents: Magnetic susceptibility and transmembrane water exchange

To characterize transverse relaxation in oxygenated whole blood with extracellular gadolinium‐based contrast reagents by experiment and simulation.

A 62-Year-Old Man With Skin Rash and an Abnormal Chest Radiograph

A 62-year-old man developed a scalp rash 2 months ago, followed by bilateral eyelid swelling. The nonpruritic rash then spread to involve most of his skin. He also had fatigue, muscle weakness, mild muscle soreness with activity, and dysphagia for solid foods for the last 3 weeks. He had no other symptoms. He had a 50 pack-year history of smoking and drank two to three shots of alcohol daily.