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ABSTRACT |
Sandrasegaran K.1; Rydberg J.1; Liang Y.1; Kopecky K.2; Buckwalter K.A.1; 1. Radiology, Indiana University School of Medicine, Indianapolis, IN; 2. Radiology, Community Group of Hospitals, Indianapolis, IN.
Address correspondence to K. Sandrasegaran (ksandras{at}iupui.edu)
Background: In the past 2 years, 40- and 64-channel CT scanners were introduced. These scanners allow faster scan speeds and longer anatomic coverage than was previously possible.
Key Issues: In this poster, we illustrate important technical features of these scanners including detector row configurations, isotropic imaging, radiation dose, cone beamartifacts, and protocols for routine scanning. We introduce relatively new features such as Z sharp function, automatic reconstruction in multiple planes from raw data or isotropic source images, and automatic X-ray tube modulation. Strategies for handling large image sets are discussed.
Teaching Points: 1. Understand technical features of 40- and 64-channel scanners that impact scanner performance and image quality. 2. Illustrated the differences in scanning protocols between 64-channel and lower channel multichannel scanners.
E091. The Essence of Iodinated Contrast Media: What Every Radiologist Must Know
Manzella A.; Borba Filho P.; Correia T.; Albuquerque A.; Fontan C.; Fonte L.; Nascimento R.; Barreto R.P.; Cardoso S.; Azevedo A.; Radiology, Hospital das Clinicas da Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil.
Address correspondence to A. Manzella (adonismanzella{at}yahoo.com.br)
Background: Iodinated contrast media are sterile iodine-containing solutions used in almost all diagnostic imaging methods. Since their advent in the 1950s, radiologic contrast media (CM) have revolutionized diagnostic imaging. Although the diagnostic value of CM is enormous, other less desirable side effects also occur. Radiologists routinely grapple with the issue of how to treat patients who are at high risk for contrast media reaction and require a contrast-enhanced study. Although iodinated contrast agents are safe and widely used, adverse events occur and questions remain about their use, safety, and interactions. Every radiologist should be intimately familiar with CM.
Key Issues: The purpose of this review is to address some of the main concerns that arise with the day-to-day use of iodinated contrast agents. These include the need for informed consent and for measurement of renal function, definition of risk factors that may predict adverse events, how to deal with patients who have had a prior reaction, and how to assess for and deal with the adverse reactions.
Format: This exhibit is organized by topics. The definition, chemical structure, classification and properties of the contrast agents are reviewed. The authors also address the risk factors, the types (classification) of adverse reactions as well as how to manage such reactions. They also comment on the role of pre-treatment regimen such as corticosteroids with or without anti-histamines as well as how to deal with special situations such as administration of CM to diabetic patients taking metformin or during pregnancy and lactation. Interactions with some drugs are also discussed.
Teaching Points: 1) To review the chemical structure, classification and properties of iodinated CM. 2) To discuss the factors which influence image quality. 3) To be aware of the decisions one has to make before injecting iodinated contrast agents. 4) To evaluate the risk of anaphylaxis, nephrotoxicity or nonrenal adverse reactions following the administration of CM and to discuss the role of pre-medication regimen. 5) To become acquainted with the appropriate treatment of such adverse reactions. 6) To discuss special situations (dialysis, use of metformin, pregnancy and lactation). 7) To provide guidelines recommending precautions to prevent possible adverse iodinated CM reactions.
E092. Abdominal Calcifications: A Teaching File
Casal S.G.1; Casal G.L.2; 1. Radiology, Duke University School of Medicine, Durham, NC; 2. Radiology, Mount Sinai Medical Center, Miami Beach, FL.
Address correspondence to S.G. Casal (sgc{at}acpub.duke.edu)
Background: The exhibit is intended to provide instructional material for the radiology trainee as well as an organized review and reference instrument for the practicing radiologist.
Key Issues: It consists of a compilation of images of calcifications found on radiographs and computed axial tomography studies of the abdomen. This series is intended to complement the presentation "Abdominal Foreign Bodies: A Teaching File" by the same authors.
Format: The exhibit is presented a self testing and learning program; it consists of 146 PowerPoint slides.
Teaching Points: At the completion of this exercise, the participant should be able to correctly identify the site and nature of the calcifications involved, as well as be alerted to the potential need for further diagnostic, interventional or surgical procedures. In some cases, it will also warn the participant of the danger of intervention.
E093. The Retroperitoneum: An Interactive Review of Normal Anatomy and Disease Processes
Taila R.R.; Mezwa D.D.; Jafri S.; Department of Radiology, William Beaumont Hospital, Royal Oak, MI.
Address correspondence to R.R. Taila (rrtaila{at}hotmail.com)
Background: The retroperitoneum encompasses various spaces that contain numerous vital organs. Many disease processes can be localized to the retroperitoneum; therefore, a thorough understanding of its anatomy is necessary to recognize the radiographic findings of pathologic states.
Key Issues: Anatomic illustrations and correlative radiographic images from multiple modalities are used to depict normal retroperitoneal anatomy and various disease processes that occur within it. Representative cases are presented as unknowns.
Format: An interactive electronic multimedia display is presented for the purpose of providing a succinct review of the retroperitoneum and the disease processes that are manifest within it. Using numerous illustrations and correlative diagnostic imaging studies, fascial planes that define the retroperitoneal compartments are first described followed by an elaboration of the extent, communication, and contents of each. Mechanisms of disease initiation, localization, and spread are then discussed. Finally, numerous clinical scenarios are presented as unknowns with sonographic, computed tomography, and magnetic resonance images provided to the viewer, who will have the opportunity to answer related multiple choice questions regarding anatomy and disease processes. The diagnosis and correlative histopathology are provided along with relevant clinical information regarding mechanism, presentation, course, and treatment of the disease. Classic radiographic findings seen on the various modalities are described for each case, which are chosen to illustrate key anatomic and pathologic principles and include neoplastic, vascular, infectious, and idiopathic etiologies.
Teaching Points: Upon completion of the presentation, the viewer will have a better understanding of the retroperitoneal anatomy and the disease processes that affect it.
E094. No Stones = Radiologist Groans: Unexpected Findings on Non-Contrast CTs for Suspected Urolithiasis
Matcuk G.R.; Wedding C.; Gupta N.; Keesara S.; Radiology, LAC/USC Medical Center, Los Angeles, CA.
Address correspondence to G.R. Matcuk (matcuk{at}usc.edu)
Background: Due to its high sensitivity and specificity in the detection of urolithiasis, unenhanced CT of the abdomen and pelvis is the preferred imaging modality in the evaluation of patients with abdominal/flank pain and hematuria. Unfortunately, the clinical picture can be misleading and can obscure other causes for abdominal pain. Thus, radiologists must be vigilant in their search for alternative causes of abdominal pain when interpreting stone protocol CT. Even when urolithiasis is present, careful examination must be made not to miss additional unsuspected pathology, some of which that ultimately may prove to be more clinically significant.
Key Issues: We will review unexpected findings from non-contrast CTs ordered for a suspicion of urolithiasis. This presentation provides examples of conditions that may mimic the presentation of urolithiasis and highlight the findings of these conditions on non-contrast CT, which are often more subtle than on contrast-enhanced studies. Examples include non-stone urinary, gastrointestinal, gynecologic, and hepatobiliary disease and pancreatic, vascular, and musculoskeletal causes. This presentation will also emphasize the importance of careful examination of the entire scan even when urolithiasis is identified to avoid the "instant happiness syndrome." While there may be a temptation to term evaluation of other structures "limited," astute interpretation can reveal other clinically important pathology which was otherwise unsuspected, including a spectrum of diverse entities from occult malignancies to calcified granulomata.
Format: This will be a PowerPoint presentation including didactic information regarding the use of non-contrast CT for suspected urolithiasis. It will cover the radiographic and clinical findings of urolithiasis and its mimics, along with a brief background summary and epidemiology for these disorders. It will provide interactive cases and quizzes illustrated with images and examples of such pathology obtained from stone protocol CTs. In some cases, this will be complemented by other imaging studies prompted by the initial scan.
Teaching Points: 1) To provide a brief review of the usefulness of stone protocol CT in the evaluation of urolithiasis 2) To provide examples of pathology that can mimic the symptoms of urolithiasis and characterize their appearance on stone protocol CT 3) To illustrate the importance of meticulously reviewing the entire exam, even when urolithiasis is positively identified, to look for additional diagnoses.
E095. Correlation of Aortic Attenuation and Hemoglobin Concentration
Valentin C.N.; Spencer A.; MacMahon H.; Radiology, University of Chicago Hospitals, Chicago, IL.
Address correspondence to C.N. Valentin (carl.valentin{at}uchospitals.edu)
Objective: A positive correlation has been described between blood density and hemoglobin level by various authors. The degree to which a reliable estimation of hemoglobin can be made has been hampered by artifact resulting in variable Hounsfield unit values. With the evolution of multi-detector CT scanners (MDCT), image quality has markedly im-proved. We sought to verify whether this apparent improvement in image quality has resulted in increased reliability of measurements of blood attenuation and their correlation with serum hemoglobin concentration in unenhanced computerized tomography.
Materials and Methods: Anemic patients' hemoglobin levels were timed to the closest blood draw prior to the scan, usually within two hours. Patients with normal hemoglobin levels were accepted within a range of up to 10 days between scanning and blood draw. The mean of three separate measurements (1 cm2) of intraluminal aortic blood near the celiac axis in Hounsfield units (HU) was used for each case as the mean blood density (p = blood). Linear regression analysis using the least-squares method was performed, considering p = blood to be the dependent variable and Hgb the independent variable. The Pearson correlation coefficient and adjusted R2 were calculated to assess collinearity of p = blood and Hgb.
Results: Regression of blood density on Hgb revealed a highly significant linear relationship (adjusted R2 = 0.581, p < 0.0005). For every increase in hemoglobin by 1 g/dL, mean celiac-aortic blood density increased by 2.24 Hounsfield units. Normality of the dependent variable was demonstrated using normal probability plots.
Conclusion: In the past, a correlation between HU and hematocrit or hemoglobin concentration has been reported. However, due to technical limitations, this correlation never attained adequate precision for clinical utility. The current study demonstrates that computed tomographic technology has not improved to a point where the mean HU density of the aorta can reliably predict hemoglobin concentration in any given case. However, our data from 102 patients indicate that HU measurements, as described in this study, provide an excellent approximation of a normal distribution. Furthermore, our data indicate that the true relationship between HU and blood Hgb is extremely likely to be linear, within the range of normal physiologic values of Hgb. As we progress in limiting artifact, this linear relationship will allow accurate measurement of hemoglobin concentration.
E096. Computed Tomography of Subcutaneous Pseudotumors
M'Dalmeida M.; Hatton B.N.; Radiology, Mount Sinai Medical Center, Miami Beach, FL.
Address correspondence to B.N. Hatton (nhatton{at}msmc.com)
Background: Familiarize the observer with the Characteristic subcutaneous Computed Tomography findings following recent liposuction.
Key Issues: Liposuction is a commonly performed cosmetic procedure that incorporates vacuum removal of the subcutaneous fatty causing local trauma. Following liposuction subcutaneous architectural distortion is present that may appear ominous. A literature search did not yield reference to post liposuction CT findings.
Format: We have three examples of post body liposuction and one case of post facial liposuction all of which presented between two days and two months post procedure but none had follow-up imaging. Consequently, it is not known when or if the subcutaneous distortion resolves. The characteristic CT findings that include subcutaneous fat stranding, formation of innumerable pleomorphic soft tissue pseudotumors, and focal edema will be presented in didactic form.
Teaching Points: This presentation will enable the observer to readily recognize the characteristic subcutaneous pseudotumors and associated findings on CT following liposuction.
E097. Histiocytosis X: From Head to Toe
Kim S.Y.1; Hong S.J.2; Kang E.Y.2; Suh S.l.2; Kim K.A.2; Kim J.H.1; 1. Diagnostic Radiology, Anam Hospital, Korea University, College of Medicine, Seoul, South Korea; 2. Diagnostic Radiology, Guro Hospital, Korea University, College of Medicine, Seoul, South Korea.
Address correspondence to S.Y. Kim (Haettm{at}hanmail.net)
Background: Histiocytosis X is a rare disorder characterized by the neoplastic proliferation of Langerhans cells that can affect various organ systems. The disease usually presents as a unifocal lytic bone lesion and can affect any age groups. Less frequently it presents as disseminated disease with multisystem involvement.
Format: On this exhibit, we will illustrate the radiologic findings of histiocytosis X involving variable organs such as CNS, bone (skull, femur, spine), lung and abdominal cavity (ureter, scrotum). We also describe the radiologic and clinical findings of Hand-Schuller-Christian disease.
Teaching Points: 1. To illustrate the radiologic findings of variable organ involvement of histiocytosis X. 2. To illustrate the radiologic and clinical findings of multiorgan involvement of histiocytosis X.
E098. Extrathoracic Manifestations of Tuberculosis.
Woo E.K.; Alyas F.; Viney Z.; Menezes L.; Tappouni R.; Vijayanathan S.; Radiology, Guys and St Thomas' Hospital, London, United Kingdom.
Address correspondence to E.K. Woo (e.woo{at}doctors.org.uk)
Background: The number of cases of Tuberculosis has been increasing over the last decade due to the increasing prevalence of acquired immunodeficiency syndrome and increasing drug resistance. Tuberculosis most commonly affects the thorax. However extrathoracic manifestations are also seen. This includes lymph nodes, genitourinary, musculoskeletal, cutaneous, gastrointestinal and central nervous systems.
Key Issues: We illustrate the manifestations of tuberculosis outside the thorax using a variety of imaging modalities (plain radiography, ultrasonography, MDCT and MR). We demonstrate cases of intracerebral, meningeal and epidural granulomata, discitis and osteomyelitis with paraspinal involvement, cutanoues, gynecological, urinary tract, ileocecal and adrenal TB.
Format: This will take the form of a power point case presentation with annotated images illustrating the appearances of extrathoracic TB by anatomical location
Teaching Points: This educational exhibit aims to familiarize the reader with the various organs that can be affected by tuberculosis and their imaging features.
E099. Creatinine Trends and the Safety of Non-ionic Contrast in Diabetics Taking Metformin HCL
Seelagan D.J.; Vyas A.R.; Jafri S.H.; Cameron J.R.; Diagnostic Radiology, William Beaumont Hospital, Royal Oak, MI.
Address correspondence to A.R. Vyas (amitrvyas{at}hotmail.com)
Objective: To analyze the trend in serum creatinine levels in patients taking Metformin HCL 48 hours after receiving non-ionic contrast and determine its relevance to the common practice of obtaining serum BUN and creatinine levels 48 hours after administration of contrast.
Materials and Methods: A total of 1,040 patients were studied over a four year period. In 559 patients taking Metformin hydrochloride, the serum creatinine was obtained before administration of intravenous non-ionic contrast and compared to the value obtained 48 hours after contrast administration. The value of 1.5 mg/dL was used as the upper limits of normal for serum creatinine and corresponds roughly to a GFR of 60 mL/min/1.73 m2, a value around which contrast mediated nephropathy and other cardiovascular comorbidities become especially prevalent in the spectrum of chronic kidney disease.
Results: The mean initial creatinine was 1.02 mg/dl and the mean post-study creatinine was 1.04 mg/dl. The mean contrast amount was 125.3 cc and the mean patient age in years was 62.9. Using multiple regression analyses, among initial creatinine, patient age, and contrast amount, initial creatinine was the only significant predictor of post study creatinine (F-Statistic = 201.89, Model p-value < 0.0001, Adjusted R2 = 0.2719).
Conclusion: In patients taking Metformin hydrochloride it may not
be necessary to routinely obtain a 48-hour creatinine follow-up value. Our
data suggests that non-ionic contrast media can be safely administered to
diabetics under age 65 without underlying renal insufficiency in an average
dose of 125 cc. The initial creatinine value positively correlated with
post-contrast creatinine in our study. With this relationship, we suggest that
it may be of benefit to use pre-contrast creatinine values to derive the
estimated GFR (eGFR) values on all patients presenting for contrast enhanced
studies. Based on eGFR, they may be stratified into risk groups for
contrast-mediated renal failure, according to the NKF/NDOQI guidelines. For
those deemed not at risk for contrast-mediated nephropathy, we propose
eliminating the practice of obtaining a 48 hour follow-up Cr value. The
benefits of reduction in health-care costs as well as patient inconvenience
would outweigh the risk of the miniscule number of patients who have a
significant rise in creatinine after contrast administration (1.1% of patients
had a post study creatinine value of 
2.0 mg/dl).
E100. Complications of Abdominal and Pelvic Procedures: CT Diagnosis
Wax B.N.1; Katz D.S.1; Badler R.L.1; Khalili M.1; Math K.R.2; Mazzie J.P.3; Weston S.R.4; Javors B.3; 1. Radiology Department, Winthrop-University Hospital, Mineola, NY; 2. Radiology Department, Beth Israel Medical Center, New York, NY; 3. Radiology Department, St Vincent's Medical Center, New York, NY; 4. Gastroenterology Division, Dept. of Medicine, Winthrop-University Hospital, Mineola, NY.
Address correspondence to B.N. Wax (bwax{at}winthrop.org)
Background: The post-procedural period is a critical time in which serious manifestations can manifest. Localization of suspected complications following abdominal and pelvic procedures can be difficult on clinical evaluation alone. For example, abdominal pain after a colonoscopy may result from simple colonic spasm to colonic perforation, hemoperitoneum, or even splenic rupture. Vague symptoms of abdominal pain following a renal biopsy may be due to minimal post-procedural bleeding into and around the kidney, or may be due to potentially life-threatening hemorrhage. In suchpatients, CT can play a crucial role in the rapid identification of complications as well as to guide subsequent patient management.
Key Issues: The purpose of this exhibit is to demonstrate the benefit of CT-assisted diagnosis in complications associated with routine minimally-invasive procedures performed in the abdomen and pelvis, including colonoscopy, cardiac catherization, IVC filter placement, fluid collection drainage, and percutaneous organ biopsy.
Format: Brief reviews of the literature of specific procedures, such as endoscopy, colonoscopy, ERCP, percutaneous biopsy, percutaneous nephrostomy, and cardiac catheterization, with demonstration of examples of the utility of CT for demonstrating the complications and for guiding further patient management.
Teaching Points: To review the spectrum of complications which may occur following various minimally invasive procedures, using abdominal and pelvic CT. To understand both common and rare complications of abdominal and pelvic medical procedures. To review the appropriate protocols when specifically performing abdominal and pelvic CT for suspected iatrogenic complications.
E101. Developing Applications for Contrast Enhanced Ultrasound
Dill-Macky M.J.1; Wilson S.R.1; Burns P.N.2; 1. Medical Imaging, University Health Network, Toronto, Ont, Canada; 2. Imaging Research, Sunnybrooke and Women's Health Sciences Center, Toronto, Ont, Canada.
Address correspondence to M.J. Dill-Macky (Marcus.Dill-Macky{at}uhn.on.ca)
Background: Contrast enhanced ultrasound (CEUS) is a rapidly evolving imaging technique with applications now extending far beyond the initial improvements achieved in Doppler ultrasound. The development of more stable microbubbles and the availability of contrast-specific, non-linear imaging techniques, now allows depiction of both morphologic and physiologic information in real-time at the high resolution of grey-scale imaging. This exhibit will review the basic physics and imaging of microbubbles and explore developing applications for CEUS.
Key Issues: Understanding enhancement: The enhancement characteristics of a focal lesion at CT and MRI are the end result of many complex factors. Lesion perfusion, vascular volume and leakiness of the vascularity contribute to the degree and distribution of enhancement with respect to the surrounding tissue at any given time. Unlike iodinated contrast and gadolinium, ultrasound contrast agents remain purely within the intravascular space. Thus the model for lesion enhancement is simplified, unique and more predictable. Liver: Hemangiomas, focal nodular hyperplasia and malignant lesions can be confidently characterized in most cases with CEUS. CEUS may be ideal for assessing treatment success immediately following radiofrequency ablation, as it is readily available in an interventional suite and inexpensive. Kidney: Confirmation of vascularity in a renal mass, the criteria used on CT and MR scan to confirm malignancy, may similarly be performed with CEUS. Aortic Endografts: CEUS has a high concordance with CTA for the detection of high-flow endoleaks. CEUS allows a higher sensitivity for detection of slow-flow endoleaks due to superior contrast resolution in delayed imaging. Prostate: CEUS depicts prostate vascularity clearly. CEUS may play a role in the mapping the distribution of tissue necrosis following local ablative procedures. Breast: Identification of changes in tumor vascular volume may predict response of the tumor to neoadjuvant chemotherapy at an early stage.
Format: Multimodality didactic presentation organized anatomically.
Teaching Points: Review the basic physics of CEUS Revise common applications for CEUS. Introduce new applications for CEUS.
E102. CT Diagnosis of Acute Appendicitis with IV Contrast Material Alone
Reddy V.; Ernst R.; Oto A.; Soloff E.; Cesani F.; Mileski W.; Department of Radiology, University of Texas Medical Branch, Galveston, TX.
Address correspondence to V. Reddy (vrreddy{at}utmb.edu)
Background: Our purpose is to demonstrate the CT appearance of acute appendicitis without administration of oral or rectal contrast material. All patients referred from the emergency department over the last three years have been examined using CT with IV contrast material alone.
Key Issues: We demonstrate the appearance of acute appendicitis in patients with varying age and body habitus. False positive cases and difficult exams are discussed. IV contrast enhanced helical CT without oral or rectal contrast is a sensitive technique for diagnosing or excluding acute appendicitis.
Format: This didactic exhibit uses static and moving GIF images to demonstrate the normal and abnormal appendix in PowerPoint format.
Teaching Points: 1. Describe the use of IV contrast-enhanced helical CT without oral or rectal contrast material for evaluation of acute abdominal pain. 2. Demonstrate the appearance of the normal and abnormal appendix without the use of oral contrast. 3. Show findings of appendicitis in patients with variable intraabdominal fat.
E103. Overcalled Acute Appendicitis on Abdominal CT: Evaluation of CT features with Histopathologic Correlation
Oto A.1; Banta B.1; Sullivan R.1; Adegboyaga P.2; Eksinar S.3; Ernst R.D.1; Swischuk L.1; 1. Radiology, UTMB, Galveston, TX; 2. Pathology, UTMB, Galveston, TX; 3. Internal Medicine, UTMB, Galveston, TX.
Address correspondence to B. Banta (bbanta{at}utmb.edu)
Objective: To retrospectively evaluate the CT findings of patients who was misdiagnosed on CT as acute appendicitis and underwent appendectomy.
Materials and Methods: The pathology reports of patients who underwent appendectomy with the suspicion of acute appendicitis between January 1, 2002 and December 31, 2004 were reviewed. Patients without pathologic evidence of acute appendicitis and false positive CT studies within 24 hours before appendectomy were included in the study group. CT findings were correlated with the histopathologic findings.
Results: Five hundred eighty three pathology reports of appendectomy were retrieved. Pediatric patients and incidental appendectomies were excluded. Out of the remaining 244 patients, 20 (8.2%) did not have pathologic evidence of acute appendicitis. Twelve of these 20 patients had CT studies performed within the 24 hours before the surgery. CT reports of 6 patients did not describe acute appendicitis. However, in the remaining 6 patients, CT report was in favor of acute appendicitis. In five of these patients, appendix was described as dilated (> 7 mm) with thickened walls and except for one patient without significant surrounding inflammation on CT. Histopathology revealed normal appendix in three, chronic appendicitis in two of these patients. One of the patients with normal appendix on histopathology had thickened muscularis propria and the other one had Meckel's diverticulitis. In one patient, appendix could not be visualized on CT but the inflammation in the right lower quadrant suggested the diagnosis of perforated appendicitis. In this patient, histopathology revealed normal appendix.
Conclusion: Meckel's diverticulitis, chronic appendicitis, normal variants of appendix and inflammation in the right lower quadrant can mimic acute appendicitis on CT and cause false positive results. Increased awareness of these pitfalls may enable the radiologists to further improve their diagnostic accuracy.
E104. Omental Infarction: CT and US Imaging
Garg A.; Singh A.K.; Radiology, University of Massachusetts Medical Center, Worcester, MA.
Address correspondence to A. Garg (asingh1{at}partners.org)
Background: Omental infarction is a benign self-limited condition with an acute clinical presentation that results from necrosis of the greater omentum. CT is usually performed to make the diagnosis as it often mimics acute appendicitis or acute cholecystitis. Sometimes US is used as the initial imaging modality, especially when clinically acute cholecystitis is suspected. Recognizing the key morphological features of omental infarction on CT and US is imperative in preventing unnecessary surgical intervention and its potential complications.
Key Issues: CT features of OI include a cake-like or whirled structure containing fat with mostly high density streaks that typically lacks a hyperattenuated ring. The lesion is closer to the abdominal wall than to the colon and usually occurs in the right upper and the lower quadrants.
Format: Poster presentation 1. Introduction 2. Imaging findings on US 3. Imaging findings on CT 4. Imaging features of conditions mimicking omental infarction 5. Summary and conclusion.
Teaching Points: 1. Understand the pathophysiology and the importance of making the diagnosis of omental infarction on CT and US. 2. Identify the key morphological features of omental infarction on CT and US. 3. Distinguish omental infarction from other acute surgical and nonsurgical causes of acute abdomen on CT.
E105. Review of the CT Findings of Small Bowel and Mesenteric Injury Following Blunt Abdominal Trauma
Walsh S.M.; Harris A.C.; Zwirewich C.V.; Nicoloau S.N.; Department of Abdominal Imaging, Vancouver General Hospital, Vancouver, BC, Canada.
Address correspondence to S.M. Walsh (sinwalsh{at}gmail.com)
Background: Injury to the small bowel and mesentery is seen in approx 5% of patients who sustain significant blunt trauma to the abdomen. The signs of these types of injury are frequently subtle and may be overlooked especially when concurrent intraabdominal injuries are present. It is very important that no delay in the diagnosis of theseinjuries occurs as failure of detection will result in significant morbidity and mortality.
Key Issues: Multislice multidetector CT with administration of oral and intravenous contrast is now recognized as the gold standard for assessment and detection of small bowel and mesenteric injury secondary to blunt abdominal trauma in the hemodynamically stable patient. We present and describe the different CT features of these injuries including - oral contrast extravasation - extraluminal air - wall hematoma - intramural air - bowel wall thickening. We also aim to ascribe significance to these findings.
Format: The exhibit will be in the form of a didactic pictorial review focusing on small bowel and mesenteric injury. The review will describe the possible mechanisms of injury. Examples of these injuries will be presented using CT as the primary imaging modality with explanation and description of the findings.
Teaching Points: We hope to review the spectrum of injuries sustained by the small bowel in cases of blunt abdominal trauma. We examine the mechanism of injury. We review and explain the CT findings in cases of these injuries. We hope to familiarize the radiologist with these CT findings and thus aid in rapid diagnosis and prevention of unnecessary morbidity and mortality from hemorrhage, sepsis and multiple organ failure.
E106. Radiological Manifestations of Motorcycle Injuries During Yearly "Biker Rally"
Green P.M.; Ernst R.; Oto A.; Reddy V.R.; Mileski W.; Cesani F.; Jones E.A.; Chaljub G.; Radiology, University of Texas Medical Branch, Galveston, TX.
Address correspondence to P.M. Green (pmgreen{at}utmb.edu)
Background: We selected images of motorcycle injuries the majority of which occurred during motorcycle rallies held yearly in Galveston, Texas. We reviewed the plain films and CT findings of twenty-nine patients treated at our Level 1 trauma center and categorized the injuries based upon the location such as head, thorax, abdomen, pelvis, and upper and lower extremity.
Key Issues: Head injuries varied from fractures to intracerebral hemorrhage. Only 5 out of 29 patients wore helmets, and all the patients who sustained head trauma did not wear helmets. Injuries to the chest included pneumothorax, pneumomediastinum, lung contusion, fracture of the clavicle, scapula, ribs and thoracic vertebrae. Intra-abdominal trauma included laceration to the spleen and liver, fracture of the lumbar vertebrae. Pelvic injuries include pelvic fractures associated with urethral tears. Extensive injuries to upper and lower extremities including complex fractures and unusual dislocations were reviewed and compiled.
Format: This didactic exhibit uses static GIF and moving GIF images in PowerPoint format to demonstrate motorcycle injuries.
Teaching Points: 1. To demonstrate the variety of motorcycle injuries occurring during a popular biker rally on a resort island. 2. To correlate CT and plain film diagnostic findings seen with motorcycle trauma and to highlight the importance of helmet use. 3. To demonstrate unusual traumatic injuries unique to motorcycle-related accidents.
E107. Upper Cervical Spine - Occult Injury and Trigger for CT Exam
Bakman M.; Chan K.; Bang C.; Basu A.; Seo G.; Monu J.U.; Imaging Sciences, University of Rochester School of Medicine and Dentistry, Rochester, NY.
Address correspondence to M. Bakman (marat_bakman{at}urmc.rochester.edu)
Background: Failure to recognize and diagnose injury to the upper cervical spine on plain radiographs can lead to dramatic and devastating consequences to the patient especially and to the radiologist. CT examination of the cervical spine aids and significantly improves diagnoses in many instances. Unfortunately it is neither economically feasible nor desirable to obtain CT on all patients. Meticulous attention to detail and zero tolerance for deviations from the usual radiographic landmarks will help select cases that should obtain additional imaging in form of CT or MRI scans.
Key Issues: Plain radiographs of patients with occult injury in the upper cervical spine and the CT images demonstrating the injury will be presented. The key imaging anomalies that should trigger additional imaging in form of CT scan will be illustrated and discussed.
Format: The proposed exhibit will combine both a quiz and interactive format.
Teaching Points: 1. The reader will become familiar with usual landmarks in the upper cervical spine radiographs. 2. The causes for disruption of these land marks will be reiterated.
E108. Isolated Mediastinal Hematoma in Blunt Thoracic Trauma: CTA and Conventional Aortographic Correlation
Wang E.C.1,2; Sammer M.1,2; 1. Radiology, Harborview Medical Center, Seattle, WA; 2. Radiology, University of Washington, Seattle, WA.
Objective: Traditionally, diagnosis of blunt aortic injury (BAI) has relied upon catheter aortography (CA). Recently, chest computed tomography angiogram (CTA) has demonstrated 99% sensitivity and specificity, suggesting CTA might replace CA.
However, CTA's can be indeterminate for BAI, demonstrating mediastinal hematoma (a possible surrogate for injury) without direct evidence of injury (pseudoaneurysm, dissection flap, or intramural hematoma). In these cases, current recommendations suggest subsequent CA; however, there has not been a dedicated investigation of this group. The current study examines such cases, and develops a scheme for classifying mediastinal hematomas in BAI.
Materials and Methods: From 2001 to June 2005, 113 blunt trauma victims with mediastinal hematoma on CTA, but no direct evidence of BAI was retrospectively identified at Harborview Medical Center via an automated search of the Radiology Information System database. CTA images were reviewed independently by the two co-authors without knowledge of the CA results, and hematoma severity was classified utilizing a system developed by the authors and based upon location and morphology. Transcripts of the CA results as well as operative, autopsy, clinic notes and subsequent pertinent imaging reports were then reviewed.
Results: 77 of the 113 patients had subsequent CA, none which demonstrated aortic injury. This yields a PPV for mediastinal hematoma in the absence of direct signs of BAI on CTA of 0% (0-3.8%; 95% CI). The 36 patients who did not undergo CA did not demonstrate aortic injury in subsequent imaging or chart reports. Finally, 12 patients died during the hospital admission; causes were documented in the medical record and confirmed by autopsy when possible to be unrelated to aortic injury. Utilizing the authors' classification scheme, there was strong correlation between the cases that underwent CA and hematoma severity (r = 0.96).
Conclusion: The CTA finding of mediastinal hematoma in the absence of direct signs of BAI is unlikely to predict BAI on CA, and CA should be reserved for those patients with extremely high clinical suspicion. The author's hematoma classification scheme may prove useful in identifying those patients in need of CA.
E109. Some Lessons Learned During Hurricane Katrina for Medical Specialists
Rodgers B.; Radiology, Tulane University, New Orleans, LA.
Address correspondence to B. Rodgers (710080{at}bellsouth.net)
Objective: During an emergency it is important to know how best to assist in the relief effort. For medical personnel, this may be governed by the provider's preconceived knowledge and skill. However, during a crisis other skills are often more important. The provider's role in influencing central authority is also emphasized.
Materials and Methods: The author is a staff Radiologist at Tulane University in New Orleans and was present in New Orleans through day 9 of Hurricane Katrina. Via observation of needs, he practiced medicine not as a Body Imager or Nuclear Physician (my usual practice), but as a General Practitioner, Pharmacist, Podiatrist, Police Doctor, and Psychologist. The author was also able to influence a small portion of the medical relief efforts at the State level and saw first hand the effects of an uncoordinated overall relief effort.
Results: Multitasking and providing care for people who could not care for themselves became major initial priorities in my neighborhood (the French Quarter). This included nursing care and finding medicine. I also cared for about 150 Police officers of all ranks. Psychological support was very important to the Police. Many had lost their homes and they were under great stress, with no relief for the first week. They also had major problems with pedal and other skin infections. At a policy level, my first hand experiences were very important to those running the Louisiana State Health Department Emergency Operations Center and provided the impetus to change some of the medical missions staged in Baton Rouge.
Conclusion: Being pliable and remembering how to be a good neighbor and citizen are perhaps most important. There was no need for a Body Imager where I was during this emergency. Lessons learned from Medical School, Internship, and lots of moonlighting helped me more than anything else. By being calm during a crisis, others will listen to you and follow well thought out plans. These lessons should hold true regardless of the type of crisis. In life we cannot always predict the effects of our actions upon others. Sometimes, just being available to care for people, whether by holding their hand and listening, or patching up a bad foot, is more important for the patient than anything else. By helping others we help ourselves.
E110. Lessons Learned During Hurricane Katrina for Medical Specialists and Those Who Provide Care during a Crisis
Rodgers B.; Radiology, Tulane University, New Orleans, LA.
Address correspondence to B. Rodgers (710080{at}bellsouth.net)
Background: During an emergency it is important to know how best to assist in the relief effort. For medical personnel, this may be governed by the provider's preconceived knowledge and skill. However, during a crisis other skills are often more important. The provider's role in influencing central authority is also emphasized.
Key Issues: The author is a staff Radiologist at Tulane University in New Orleans and was present in New Orleans through day 9 of Hurricane Katrina. Via observation of needs, he practiced medicine not as a Body Imager or Nuclear Physician (my usual practice), but as a General Practitioner, Pharmacist, Podiatrist, Police Doctor, and Psychologist. The author was also able to influence a small portion of the medical relief efforts at the State level and saw first hand the effects of an uncoordinated overall relief effort. Multitasking and providing care for people who could not care for themselves became major initial priorities in my neighborhood (the French Quarter). This included nursing care and finding medicine. I also cared for about 150 Police officers of all ranks. Psychological support was very important to the Police. Many had lost their homes and they were under great stress, with no relief for the first week. They also had major problems with pedal and other skin infections. At a policy level, my first hand experiences were very important to those running the Louisiana State Health Department Emergency Operations Center and provided the impetus to change some of the medical missions staged in Baton Rouge.
Format: Didactic, providing case examples of the importance of General Practice and how we as medical specialists can provide this.
Teaching Points: How to be an effective medical care giver during a crisis.
E111. Deployment Radiology: Imaging of Disease and Non-Battle Injury in the War Zone
Statler J.D.1,4; Montilla-Soler J.2,4; Harcke H.T.3,4; 1. Radiology, Madigan Army Medical Center, Tacoma, WA; 2. Nuclear Medicine, Walter Reed Army Medical Center, Washington, D.C.; 3. Radiologic Pathology, Armed Forces Institute of Pathology, Washington, D.C.; 4. Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD.
Address correspondence to J.D. Statler (jstatrad{at}aol.com)
Background: For the military radiologist deployed to the combat zone, the vast majority of imaging involves the radiology of trauma. A smaller but more challenging portion of the day's work involves the diagnosis of medical illness. In the third world setting of most ongoing military operations, the radiologist plays a crucial role in the diagnosis of rare congenital and acquired diseases. As laboratory support is rudimentary, and all surgical/medical subspecialties are not represented, imaging plays a critical role in diagnosis and management of disease.
Key Issues: The experience of three radiologists, spanning over a year of diagnostic imaging at a combat support hospital in Afghanistan, was compiled. Each physician has contributed cases in which the military radiologist played a key role in the diagnosis and management of medical disease. This exhibit will showcase the use of multiple imaging modalities including plain film, ultrasound, fluoroscopy, and computed tomography in the diagnosis and treatment of disease and non-battle injury encountered in the war zone. Emphasis is placed on the practice of radiology in an austere and hostile environment.
Format: The exhibit will be a didactic, case based presentation organized by pathology.
Teaching Points: The participant will gain an appreciation of the unusual challenges presented by practicing radiology in an austere and harsh environment. The participant will learn characteristic and atypical features of congenital and acquired diseases of the central nervous, vascular, musculoskeletal, gastrointestinal, and genitourinary systems.
E112. Craniofacial Trauma at a Combat Support Hospital in Afghanistan
Statler J.D.1,4; Tempel C.G.2; Harcke H.T.3,4; 1. Radiology, Madigan Army Medical Center, Tacoma, WA; 2. Oral and Maxillofacial Surgery, Walter Reed Army Medical Center, Washington, D.C.; 3. Radiology, Armed Forces Institute of Pathology, Washington, D.C.; 4. Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD.
Address correspondence to J.D. Statler (jstatrad{at}aol.com)
Objective: This exhibit details the craniofacial trauma cases seen at the combat support hospital at Bagram Airfield, Afghanistan during Operation Enduring Freedom.
Materials and Methods: All patients sustaining significant craniofacial trauma were evaluated with computed tomography. All scans were unenhanced. Standard protocols were basic. Pitch was 1:1, kV 110-130, and mA 175-250. Head exams were performed using 5mm continuous axial slices from skull base to vertex. Face, orbit, mandible, and cervical spine exams were performed using 3 mm continuous axial slices over the structure scanned. No reformats were generated. All exams were reviewed on the monitor by the radiologist and the oral surgeon. CT findings were confirmed at surgery. All operative patients were seen in clinic for follow-up at varying time intervals following initial visit.
Results: During the period of 16 December 2002 to 15 March 2003, 55 patients underwent computed tomography for evaluation of craniofacial trauma. The majority of patients (81%) evaluated were local nationals. Mechanisms of injury varied, but most (44%) local nationals were injured in landmine related incidents. Others sustained injury in motor vehicle accidents (16%), gunshot wounds, grenade attacks, and falls from height. Complex facial fractures were seen in 22% of local nationals presenting with craniofacial trauma, and 13% of these patients sustained ruptured globes. Eleven percent of local nationals died as a result of their injuries. The majority (55%) of Coalition Forces and DOD civilians were injured by blunt trauma. Of coalition soldiers evaluated, 40% sustained their wounds in combat. None of these patients died as a result of their injuries. Several of the patients imaged presented with complex craniofacial injury patterns which would have been challenging or impossible to diagnose and treat without cross-sectional imaging.
Conclusion: Craniofacial injuries encountered in the combat zone are complex, and affect soldiers and civilians alike. The mechanisms of injury involve high-energy, high-explosive devices that have no direct peacetime correlate. Computed Tomography is an indispensable tool for the evaluation and treatment of these injuries.
E113. Tumors of the Perivascular Epithelioid Cell (PEComas): Imaging Findings with Radiologic-Pathologic Correlation
Prasad S.R.1; Sahani D.V.2; Narra V.R.3; Mino M.4; Humphrey P.A.5; Chintapalli K.N.1; 1. Radiology, University of Texas Health Science Center @ San Antonio, San Antonio, TX; 2. Radiology, Massachusetts General Hospital, Boston, MA. 3. Pathology, Massachusetts General Hospital, Boston, MA. 4. Radiology, Mallinckrodt Institute of Radiology, St. Louis, MO; 5. Pathology, Washington University in St. Louis, St. Louis, MO.
Address correspondence to S.R. Prasad (prasads{at}uthscsa.edu)
Background: Tumors of the Perivascular Epithelioid Cell (PEComas) represent a novel, heterogeneous group of neoplasms characterized by specific histological, immunohistochemical and ultrastructural findings. These tumors demonstrate a wide spectrum of clinico-biological behavior and imaging findings. Perivascular Epithelioid Cell (PEC), as the name implies, is a unique cell that is characterized by perivascular distribution, and epithelioid morphology. This distinctive cell co-expresses muscular and melanogenesis marker - HMB45.
Key Issues: PEComas are found at a variety of somatic and visceral locations including liver, kidney, uterus, gut, and extremity soft tissue. The falciform ligament of the liver is a characteristic target site. The family of PEComas includes pulmonary "sugar"; tumor, lymphangiomyoma, angiomyolipomas, clear cell tumor of the falciform ligament, and abdominopelvic sarcoma of perivascular epithelioid cells. A subset of patients with PEComas manifests tuberous sclerosis. Histopathological and cross-sectional imaging findings of PEComas are presented.
Format: Didactic (Imaging findings, Gross and histopathology features and radiologic-pathologic correlation).
Teaching Points: 1. To review the histological spectrum of the tumors of the perivascular epithelioid cell (PEComas) 2. To discuss cross-sectional imaging findings of PEComas. 3. To correlate imaging findings with gross and histopathological findings.
E114. Cross-Sectional Imaging Findings of Venous Thrombosis Throughout the Body
Wax B.N.; Jain M.; Hoffman J.; Katz D.S.; Pinto M.H.; Fruauff A.A.; Ortiz A.O.; Department of Radiology, Winthrop-University Hospital, Mineola, NY.
Address correspondence to M. Jain (mjain{at}winthrop.org)
Background: Many cross-sectional imaging studies are ordered specifically to diagnose or exclude venous thrombosis, although such thrombosis may be found unexpectedly or incidentally on such imaging examinations.
Key Issues: The purpose of this poster is to review the imaging findings of thrombosis of veins throughout the body, including the lower extremities, abdomen, pelvis, chest, neck, and head, using examples on US, CT, and MR studies. We will also discuss optimal protocols including contrast delivery and timing, when specifically searching for venous thrombosis on CT or MR examinations. The clinical presentation and imaging findings of specific venous thromboses will be discussed, and the literature briefly overviewed, for specific sites of thrombosis. This will include portal vein, hepatic vein, renal vein, and ovarian vein thrombosis; superior and inferior vena cava thrombosis; internal jugular vein thrombosis; and venous thrombosis within the superior sagittal sinus.
Format: Case presentation intermixed with literature review.
Teaching Points: To overview the findings of thrombosis of veins throughout the body. To review the roles of various cross-sectional imaging tests for suspected venous thrombosis. To understand the appropriate protocols for performing cross-sectional imaging for suspected venous thrombosis.
E115. Sonographic and Color-Doppler Findings of Small Bowel Parietal Changes from Various Degree of Low-flow States or Impaired Venous Drainage Due to Mesenteric Vascular Disease
Romano S.1; Daniele S.1; Di Nuzzo L.1; Pinto F.1; Pinto A.1; Grassi R.2; Romano L.1; 1. Department of Diagnostic Imaging, A.Cardarelli Hospital, Naples, Italy; 2. Institute of Radiology, Second University of Naples, Naples, Italy.
Address correspondence to S. Romano (stefromano{at}libero.it)
Objective: Purpose of our study was a retrospective evaluation of sonographic findings in patients affected by vascular disorders of the small bowel from ischemia to infarction.
Materials and Methods: We considered the sonographic findings of 115 patients with proven small bowel ischemia or infarction of the small bowel from mesenteric vascular disorders. Patients with ischemia or infarction as consequence of intestinal obstruction were not considered in our series. All diagnoses were confirmed by surgery, pathology and/or interventional vascular procedures. All examinations were performed by experienced emergency sonographist. Color Doppler examination was additionally performed in 56 cases; ultrasound contrast-enhancement was also performed in 4 cases. Imaging findings considered were: perviety of superior mesenteric artery and vein, parietal thickness and appearance of the layers, caliber of the loop, peritoneal fluid, peristalsis.
Results: Based on the imaging findings a four stages classification of the findings was made for disease of either venous or arterial origin. Patient final distribution was listed according to the following phases of ischemic compromission: "initial suspicion," "advanced suspicion," "confirmed diagnosis," and "late diagnosis." There was a related three-stage color signal pattern, where performed: absence, reduction, normal.
Conclusion: Sonographic evaluation of patients with acute abdomen and suspected intestinal ischemia may be an effective first tool in differential diagnosis from ischemia to infarction of small bowel.
E116. A Pictorial Review of the Imaging Findings in Sickle Cell Anemia
Viney Z.N.; Alyas F.; Tappouni R.; Woo E.K.; McWilliams S.; Radiology, Guy's and St Thomas' Hospitals, London, United Kingdom.
Address correspondence to Z.N. Viney (poliov{at}hotmail.com)
Background: Sickle cell anemia (SCA) is a debilitating condition caused by abnormal hemoglobin (HbS). Red blood cells (RBCs) containing HbS have a tendency to aggregate and cause vessel wall damage, especially at times of hypoxia. This leads to tissue ischemia and infarction, which is responsible for the bone pain and acute chest syndrome which characterize the disorder. Almost any end organ can be affected. Anemia also occurs as a result of the abnormal RBCs being removed from the circulation, although this is generally well tolerated.
Key Issues: Acute painful crises occur due to bone marrow infarction. This leads to medullary infarction and avascular necrosis (particularly of the hips, shoulders and vertebrae). Children have a propensity towards dactylitis. Sluggish blood flow within bones predisposes to osteomyelitis. Acute chest syndrome (ACS) comprises shortness of breath, fever and chest pain in combination with new air space shadowing on the chest radiograph (CXR). A variety of underlying factors predispose to ACS, including infection, pulmonary infarction and fat emboli which form as a result of bone infarction. The CXR findings are non-specific, showing areas of consolidation, usually in the lower zones, sometimes with pleural effusions. Often the CXR is normal. No particular feature helps distinguish the cause of the ACS. Repeated events may lead to fibrosis and pulmonary hypertension. The chronic anemia contributes to cardiomegaly, which is often seen in those with SCA. Significant motor and cognitive disability occurs in approximately one quarter of patients. Vessel stenosis and occlusion leads to stroke (often sub-clinical), especially involving watershed territories. Aneurysm formation, subarachnoid haemorrhage and cerebral atrophy also occur. Other complications likely to come to the radiologist's attention include: splenic infarction (which leads to an increased risk of bacterial infection); renal papillary necrosis; gallstones and testicular infarction.
Format: Illustrated examples using a variety of imaging modalities will be used to demonstrate the above.
Teaching Points: With good supportive care, patients with SCA live into middle age. Understanding the pathophysiology gives a better appreciation of the complications and imaging findings that one is likely to encounter as a radiologist.
E117. Sickle Cell Disease: A Spectrum of Radiological Findings from Head to Toe
Alim A.A.1; Gentili A.2; 1. Radiology Service, Dhahran Medical Center, Dhahran, Saudi Arabia; 2. Radiology, UCSD - Thornton Hospital, La Jolla, CA.
Address correspondence to A.A. Alim (awoni2001{at}ureach.com)
Background: Background information: Sickle cell disease and anemia is an autosomal recessive genetic disease that results in a defective form of hemoglobin, hemoglobin S (HbS). When HbS loses oxygen, it crystallizes and deforms the red blood cell into a sickle shape The major consequence of the sickle shape of the red blood cells is that they become much less deformable; hence obstructing the microcirculation. Tissue hypoxia ensues, thus promoting further sickling.
Key Issues: The clinical radiological manifestations of sickle cell anemia are diverse, and any organ system may be affected. These manifestations are related to vasoocclusive, hematological or/and infectious etiology. Vaso-occlusive crises are triggered by the increased sickling of the red blood cells. Hematologic crises are manifested by a sudden exacerbation of anemia, due to acute splenic sequestration in which sickled cells block splenic outflow. This leads subsequently to the pooling of peripheral blood in the engorged spleen (seen in young patients with functioning spleens). Infectious crises are caused by the underlying functional asplenia in most adults with sickle cell anemia, leading to defective immunity against encapsulated organisms (e.g., Haemophilus influenzae, Streptococcus pneumoniae). The exhibit will demonstrate the radiological findings during the crises as well as the chronic complications. It will also cover all organ systems, but with particular emphasis on skeletal findings.
Format: This didactic exhibit will be structured to systematically display the usual as well as the unusual radiological presentations of the sickle cell disease. The emphasis is to cover the findings in a multimodality fashion by anatomic location.
Teaching Points: Learn radiographic manifestations of sickle cell disease. Distinguish acute from chronic complications of sickle cell disease.
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