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This document outlines the usefulness of available diagnostic imaging for patients without known coronary artery disease and at low probability for having coronary artery disease who do not present with classic signs, symptoms, or electrocardiographic abnormalities indicating acute coronary syndrome but rather with nonspecific chest pain leading to a differential diagnosis, including pulmonary, gastrointestinal, or musculoskeletal pathologies. A number of imaging modalities are available to evaluate the broad spectrum of possible pathologies in these patients, such as chest radiography, multidetector CT, MRI, ventilation-perfusion scans, cardiac perfusion scintigraphy, transesophageal and transthoracic echocardiography, PET, spine and rib radiography, barium esophageal and upper gastrointestinal studies, and abdominal ultrasound. It is considered appropriate to start the assessment of these patients with a low-cost, low-risk diagnostic test such as a chest x-ray. Contrast-enhanced gated cardiac and ungated thoracic multidetector CT as well as transthoracic echocardiography are also usually considered as appropriate in the evaluation of these patients as a second step if necessary. A number of rest and stress single-photon emission CT myocardial perfusion imaging, ventilation-perfusion scanning, aortic and chest MR angiographic, and more specific x-ray and abdominal examinations may be appropriate as a third layer of testing, whereas MRI of the heart or coronary arteries and invasive testing such as transesophageal echocardiography or selective coronary angiography are not considered appropriate in these patients. Given the low risk of these patients, it is mandated to minimize radiation exposure as much as possible using advanced and appropriate testing protocols. The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

There has been no comparison of concordance rates for residents' and faculty members' interpretations of pulmonary embolism (PE) CT and ventilation/perfusion (V/Q) studies. If significantly different rates of agreement are demonstrable, this could influence which test is ordered during off hours. The purpose of this study was to evaluate how the performance of residents compared with that of faculty members in interpreting these two modalities.Interobserver agreement between preliminary resident reports and final attending radiologist interpretations was calculated retrospectively for PE CT studies (n = 1,179) and V/Q scans (n = 331) interpreted by on-call residents from April 2007 to October 2008. Discordant cases were reviewed for clinical significance and outcomes at 3 months. Interobserver variability was also evaluated relative to residents' training levels and faculty members' years of experience.Interobserver agreement between faculty members and residents was substantial, at 95% for PE CT (κ = 0.77) and 77.9% for V/Q scans (κ = 0.67). Although changes in interpretation were significantly more common with V/Q scans (22.1% vs 5%; χ(2).0001), the rates of clinically significant discrepancy did not differ significantly between the modalities (2.1% for V/Q vs 1.2% for PE CT; χ(2)P = .20). The overall discrepancy rate and the rate of clinically significant discrepancy did not correlate with residents' training levels or faculty members' years of experience.Concordance rates for residents' interpretations of V/Q scans and PE CT studies were high, and discrepancies resulting in changes in patient management were rare for both modalities. Residents' preliminary interpretations of both modalities are reliable and safe for making initial patient management decisions.

Focal incidental renal lesions are commonly encountered on positron emission tomography (PET)/computed tomography (CT) imaging. The vast majority of these lesions are benign. However, the interpretation of renal lesions can be problematic if the imaging criteria of simple cysts are not met. Limited literature exists on the characterisation of renal masses with metabolic imaging. The purpose of this article is to focus on the imaging features of benign and malignant renal masses with PET/CT. The lesions discussed include renal cyst, angiomyolipoma, oncocytoma, renal cell carcinoma, renal metastases and other infiltrating neoplastic processes affecting the kidney. Both the anatomical and metabolic features which characterise these benign and malignant entities are described. We emphasise the importance of viewing the CT component to identify the typical morphological features and discuss how to best use hybrid imaging for management of renal lesions. Metabolic imaging has a promising role in the imaging of renal lesions and can help prevent unnecessary biopsies and ensure optimal management of suspicious lesions.

Esophageal cancer has been increasing in incidence for the last several decades. The current staging evaluation includes computed tomography, endoscopic ultrasonography, and F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), which influences the treatment options. PET/CT is limited in its ability to differentiate hypermetabolic metastatic disease from acute/chronic inflammatory conditions, and this must be considered during interpretation. This is the case report of a 77-year-old man with esophageal cancer whose PET/CT demonstrated increased F-18 FDG uptake in the right lobe of the liver. This was originally interpreted at an outside institution as suspicious for metastatic disease, which would have precluded potential surgical cure. Subsequent reinterpretation and additional imaging including magnetic resonance imaging suggested that the uptake in the liver was likely due to adjacent gallbladder inflammation. On the basis of this interpretation, an abdominal exploration, liver biopsy, cholecystectomy, and transhiatal esophagectomy were performed. Final pathology of the gallbladder revealed perforated cholecystitis and a pericholecystic abscess (related to a prior septic episode), which were responsible for the increased radiotracer uptake. This case is presented to illustrate the importance of considering benign etiologies that may mimic metastatic disease when interpreting PET/CT scans.

In the UMC Utrecht a prototype MRI accelerator has been installed to investigate the feasibility of real-time, MRI guided radiotherapy. The system consists of a 6 MV Elekta (Crawley, UK) accelerator and a 1.5 T Philips (Best, The Netherlands) MRI system. The system is installed in a standard radiotherapy bunker. The bunker is at the corner of a block of six bunkers, so there are three neighbouring clinical Elekta accelerators. During ramping of the magnet, the magnetic fringe field in the two nearest bunkers was measured as a function of the magnetic field strength of the MRI magnet. At 8 m, a maximum increase of 1.5 G was measured, at 12 m, 0.6 G. This is up to three times the earth's magnetic field. The clinical accelerators are needed to be re-calibrated in order to operate in such an external magnetic field. The resulting radiation field flatness of the clinical accelerators was measured and was similar to the situation before ramping the magnet.

The purpose of this study was to determine the diagnostic yield and clinical importance of delayed whole-body bone scintigraphy in directed three-phase examinations.The records of 400 consecutively registered patients who underwent combined three-phase and delayed whole-body (99m)Tc-methylene diphosphonate bone scintigraphy for a variety of indications were reviewed. Clinical indications, findings, recommendations, and outcome were assessed.Three-phase bone scintigraphy was performed on 156 men and boys and 244 women and girls (61%). Fifty-two patients (13%) were 17 years old or younger, and 236 patients (59%) were older than 40 years. The mean increase in study duration due to whole-body imaging was 25 minutes (range, 21-31 minutes). Excluding the three-phase area of interest, the whole-body examination had a normal tracer distribution in 131 examinations (33%), showed solely degenerative changes in 103 (26%), and showed findings unrelated to the area of interest in 166 patients (41%). In no case did the findings outside the area of interest alter the diagnosis or diagnostic certainty in the three-phase study, but those findings did generate 82 recommendations for additional diagnostic investigation. As a direct result of the recommendations, clinicians requested 18 radiographic, two CT, one MRI, and one ultrasound examinations, one additional bone scan, and two referrals to a consultant. Recommendations based on findings outside the three-phase area of interest affected treatment in one case: Temporomandibular joint uptake resulted in a referral for physical therapy.For most indications, delayed whole-body imaging after directed three-phase bone scintigraphy does not improve diagnostic yield, does not alter patient care, and may be an unnecessary use of medical resources.

A 27-year-old male presented with recurrent abdominal pain and high volume hematochezia despite undergoing extensive testing and a right hemicolectomy 3 years prior for a linear bleeding ulceration in the ascending colon. Studies at the University of Michigan included esophagogastroduodenoscopy (EGD), colonoscopy and video capsule endoscopy (VCE), revealing an arteriovenous malformation (AVM) in the terminal ileum. He was hospitalized for recurrent symptoms. His presentation suggested a small bowel source of obscure-overt GI bleeding based on prior non-diagnostic colonoscopy and EGD and a bilious nasogastric lavage. Tagged red blood cell scan localized bleeding to the right lower quadrant. Colonoscopy showed fresh blood in the terminal ileum without a clear source. Angiography showed no evidence of bleeding or terminal ileal AVM. A novel Meckel’s scan fused with SPECT imaging showed focal uptake in the terminal ileum. The patient underwent Meckel’s diverticulectomy with sparing of adjacent bowel and has remained asymptomatic for 19 months. This case illustrates that patients with obscure-overt GI bleeding require a step-wise multi-modality diagnostic work-up. Because Meckel’s scans are false-positive in 28% of adults, Meckel’s scan fused with SPECT imaging may offer an approach to refine diagnostic accuracy of either scan alone, but requires further investigation. Exploratory laparotomy should be reserved as a last option and is best performed with intraoperative endoscopy.

In this paper, we study the combined effect of concave and convex nonlinearities on the number of solutions for a semilinear elliptic system ( E λ , μ ) involving nonlinear boundary condition and sign-changing weight function. With the help of the Nehari manifold, we prove that the system has at least two nontrivial nonnegative solutions when the pair of the parameters ( λ , μ ) belongs to a certain subset of R 2 .

Rationale and Objectives We sought to assess the ability of 18F-fluoro-2-deoxy- d -glucose (FDG) PET/CT to distinguish adrenal adenomas from nonadenomas in patients with suspected malignancy. Methods Fifty-nine adrenal masses were evaluated with coregistered 18F-FDG PET (PET/CT). Two reviewers independently graded uptake of 18F-FDG by visual inspection of the adrenal mass in comparison to liver and background. CT attenuation value of the adrenal mass and the standardized uptake value (SUV) of the mass, liver, background, and primary neoplasm (when visible) were measured. Mean SUVs of the adrenal mass, liver, and background and ratios of the SUVs were calculated. Results Of 47 adenomas, 43 measured 10 HU on unenhanced CT. Using qualitative assessment of FDG activity in the adrenal mass compared with liver, adenomas were less than, equal to, or more active than the liver in 51%, 38%, and 10%, respectively. Nonadenomas were less than, equal to, or more active than liver in 0%, 25%, and 75%, respectively. The mean SUV of adenomas (4.2) was significantly lower (P = .002) than that of their primary malignancies (9.2) but not that of liver (4.3). The mean SUV of adenomas was not significantly different than that of nonadenomas (5.2), but the mean adrenal/liver ratio (1.0) for the adenomas was significantly lower (P = .006) than that of the nonadenomas (2.1). Conclusion Adrenal adenomas were better differentiated from nonadenomas using unenhanced CT measurements in combination with ratios of the SUVs. Adrenal mass activity, which was visibly less than liver, was more specific for adenoma, whereas adrenal mass activity visibly greater than liver was more specific for malignancy.

Primary imaging options in patients at low risk for coronary artery disease (CAD) who present with undifferentiated chest pain and without signs of ischemia are functional testing with exercise or pharmacologic stress-based electrocardiography, echocardiography, or myocardial perfusion imaging to exclude myocardial ischemia after rule-out of myocardial infarction and early cardiac CT because of its high negative predictive value to exclude CAD. Although possible, is not conclusive whether triple-rule-out CT (CAD, pulmonary embolism, and aortic dissection) might improve the efficiency of patient management. More advanced noninvasive tests such as cardiac MRI and invasive imaging with transesophageal echocardiography or coronary angiography are rarely indicated. With increased likelihood of noncardiac causes, a number of diagnostic tests, among them ultrasound of the abdomen, MR angiography of the aorta with or without contrast, x-ray rib views, x-ray barium swallow, and upper gastrointestinal series, can also be appropriate. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. This recommendation is based on excellent evidence, including several randomized comparative effectiveness trials and blinded observational cohort studies.

OBJECTIVE. Extraosseous radioactivity outside of the expected biodistribution is often encountered on 99mTc–methylene diphosphate (MDP) bone scintigraphy, and proper interpretation requires an understanding of the mechanisms underlying this uptake and knowledge of the possible causes, depending on the site or structure involved. CONCLUSION. We present examples of extraosseous radiotracer uptake seen on 99mTc-MDP bone scans in which either SPECT with integrated CT or correlative imaging improved the study's interpretation.

Venous malformations of the parotid glands are uncommon and can be difficult to confirm on routine anatomical imaging alone because of overlap of imaging features with other more common parotid lesions. (99m)Tc RBC scans combined with SPECT/CT offer a noninvasive way to diagnose parotid venous malformations without the need for biopsy. Combined with anatomical findings of phleboliths (when present), the diagnosis can be reliably determined. We present a case where MRI and biopsy were inconclusive, but the SPECT/CT was used to confirm the suspicion of a benign venous malformation.

To determine if ultrasonographic (US) renal shear-wave speed (SWS) measurements obtained either before or after intravenous diuretic administration can be used to discriminate obstructive hydronephrosis from unobstructive hydronephrosis in children, with diuretic renal scintigraphy as the reference standard.Institutional review board approval and parental informed consent were obtained for this HIPAA-compliant prospective cross-sectional blind comparison with a reference standard. Between November 2012 and September 2014, 37 children (mean age, 4.1 years; age range, 1 month to 17 years) underwent shear-wave elastography of the kidneys immediately before and immediately after diuretic renal scintigraphy (reference standard for presence of urinary tract obstruction). Median SWS measurements (in meters per second), as well as change in median SWS (median SWS after diuretic administration minus median SWS before diuretic administration) were correlated with the amount of time required for kidney radiotracer activity to fall by 50% after intravenous administration of the diuretic (T1/2). Median SWS measurements were compared with degree of obstruction and degree of hydronephrosis with analysis of variance. Receiver operating characteristic (ROC) curves were created.Radiotracer T1/2 values after diuretic administration did not correlate with median SWS measurements obtained before (r = -0.08, P = .53) or after (r = -0.0004, P.99) diuretic administration, nor did they correlate with intraindividual change in median SWS (r = 0.07, P = .56). There was no significant difference in pre- or postdiuretic median SWS measurements between kidneys with scintigraphic evidence of no, equivocal, or definite urinary tract obstruction (P.5) or for median SWS measurements between kidneys with increasing degree of hydronephrosis (P.5). ROC curves showed poor diagnostic performance of median SWS in discerning no, equivocal, or definite urinary tract obstruction (area under the ROC curve ranged from 0.50 to 0.62).US SWS measurements did not enable discrimination of obstructive hydronephrosis from unobstructive hydronephrosis in children.

The detection and staging of many cancers is rapidly becoming dependent on positron emission tomography (PET) with the glucose analog 18 fluorine fluorodeoxyglucose (FDG). FDG demonstrates increased uptake in a majority of malignant lesions as well as an increasing number of benign conditions that can be confused with a malignant neoplasm. Osseous injury associated with anterior cruciate ligament (ACL) and meniscal tears have been detected with bone scanning agents.

A machine vision approach to on-line slab camber measurement in the hot strip steel mill at Port Talbot is described. A digital image of the hot slab is transformed to obtain a plan view and its position is located using greyscale thresholding and binary morphology. The slab centre-line is extracted as an approximate medial axis from its Euclidean distance map and camber is calculated from the curvature of this centre-line. Additional processing stages are included to make the process robust to industrial conditions. The technique is validated through comparison with manual camber measurements made off-line and in this way the curvature accuracy of the final technique is shown to be ±0.9 × 10−3 m−1 at the 95% confidence level.

FDG-PET imaging has significantly altered the workup of the oncologic patient. With the introduction of combined FDG-PET/CT scanners, there has been a dramatic improvement in lesion detection, lesion characterization and accurate lesion localization. As attenuation correction can be attained with the CT images, PET exam times have been dramatically reduced, by as much as 50% in many instances. In this overview we briefly outline the advantages of CT/PET in oncology especially in diagnosis and clinical management of the common tumor types for which it is mainly used.

A system of reaction–diffusion equations modelling a population divided into juvenile and adult age groups is studied. The system is not co-operative but its linear part is and this makes it possible to establish existence, non-existence and stability results for non-negative solutions of the system in terms of the principal eigenvalue of the corresponding linearized system.

The post-glacial vegetation and fire history of high-elevation regions on southern Vancouver Island is described using palynological and charcoal records from Porphyry and Walker lakes. A zone consisting mainly of Artemisia , Poaceae, and ferns occurs in the basal clay at Porphyry Lake and may represent a non-arboreal ecosystem in a late-Wisconsin glacial refugium. At both sites, a fire-free Pinus contorta zone occurs before ca 14 160 calendar years before present (cal BP). Climate at this time is interpreted as being cool to cold and dry. Mixed conifer forests of Picea , Abies , Tsuga mertensiana and Pinus contorta replaced the Pinus contorta woodlands after ca 14 160 cal BP. Fires are recorded for the first time. Climate is interpreted as cool and moist. Forests of Abies , Picea , Tsuga heterophylla , Pseudotsuga menziesii , and Alnus developed and expanded during the early-Holocene from ca 11 400–9910 to 7700–7300 cal BP as climate warmed and dried. Charcoal increased during this interval, indicating only slightly more fire activity and reflecting continued moist conditions at high elevations. In the mid-Holocene from ca 7700–7300 to 5200–4900 cal BP, Tsuga heterophylla pollen values increased as forests became dominated by Tsuga heterophylla , Picea , and Abies with Alnus in response to increased moisture. The increase in charcoal influx at this time may reflect an increase in slope wash and erosion resulting from a wetter climate rather than an increase in fire incidence. Starting at ca 5200–4900 cal BP, a further increase in Tsuga heterophylla combined with an increase in Tsuga mertensiana and Cupressaceae pollen suggest that the late-Holocene was characterised by increasing moisture and decreasing temperatures. Late-Holocene forests consisted predominately of Tsuga heterophylla , Tsuga mertensiana , Cupressaceae, and Pinus contorta . A slight reduction in charcoal influx at ca 4600 cal BP implies fewer fires. A recent increase in charcoal at Walker Lake at 1700 cal BP may reflect anthropogenic burning. The timing of events and response of taxa on southern Vancouver Island are comparable to other coastal sites in northwestern North America, suggesting that past ecosystems were widespread and contemporaneous. Palaeoecosystem changes detected in one region of the Pacific Northwest likely reflect a widepsread response to climate throughout the ∼2500 km long zone, a zone that today is home to half of the world’s remaining coastal temperate rainforest.

Hepatic uptake on an MDP bone scan is a non-specific finding. When present, the etiology needs to be determined. The differential diagnosis depends on the pattern of uptake. Metastatic breast and colon cancer are frequent causes of focal faint uptake. Diffuse uptake is rare, but can be seen with hepatitis, amyloid, and IV gadolinium administration. In addition, aluminum breakthrough from the molybdenum generator can cause colloid formation and subsequent diffuse hepatic uptake. We present a case of diffuse uptake in a patient with acute hepatic failure. The etiology of the failure was extensive thrombosis of the inferior vena cava (IVC).

Renal cell carcinoma has a variable uptake of F-FDG resulting in poor sensitivity and limited clinical application. There is intense interest in improved molecular imaging of this condition. We present a case of a 64-year-old man with known metastatic renal cell carcinoma found to have intense uptake of Rb but not F-FDG in multiple thoracic metastases seen on imaging performed to assess myocardial hibernation.

We investigate the existence of principal eigenvalues (i.e., eigenvalues corresponding to positive eigenfunctions) for the boundary value problem -Au(x) = Ag(x)u(x) onD; , (x) +au(x) 0on D a (x) + au(x) = 0 on AD, where D is a bounded region in RN with smooth boundary, g: D -R is a smooth function which changes sign on D, and a E R. Such problems have been studied in recent years because of associated nonlinear problems arising in the study of population genetics (see [3]). The study of the linear ordinary differential equation case, however, goes back to Picone and Bocher (see [2]). Attention has been confined mainly to the cases of Dirichlet (a = oc) and Neumann boundary conditions. In the case of Dirichlet boundary conditions it is well known (see [4]) that there exists a double sequence of eigenvalues for (1)> * **\> 0); in the case where fD g(x) = 0 there are no positive and no negative principal eigenvalues. We shall investigate how the principal eigenvalues of (1), depend on a, obtaining new results for the case where a 0, probably because it is more natural that the flux across the boundary should be outwards if there is a positive concentration at the Received by the editors April 30, 1997. 1991 Mathematics Subject Classification. Primary 35J15, 35J25.

Most diagnostic imagers are familiar with the classic patterns of altered metabolism seen in Alzheimer disease, frontal temporal dementia, and dementia with Lewy bodies. However, awareness of other conditions that can cause cognitive impairment is crucial when interpreting FDG brain PET studies. This is particularly true of infectious and inflammatory processes, such as viral encephalitis, which should be diagnosed and treated on an emergent basis. In addition, altered metabolism can be caused by autoimmune paraneoplastic and encephalitic syndromes. We report a case of autoimmune limbic encephalitis encountered as part of evaluation for atypical onset cognitive impairment.

We study a reaction–diffusion version on all of RNof the logistic equation of population growth in which the birth rate depends on the spatial variable and may assume both positive and negative values. Our results which are obtained by the construction of sub- and supersolutions and the study of asymptotic properties of solutions show the interplay between the birth rate of the species and the extent of diffusion in determining the existence or nonexistence of nontrivial steady-state distributions of population.

Aim The aim of this study was to evaluate our institutional experience with single-photon emission computed tomography/computed tomography (SPECT/CT) hepatobiliary imaging as a problem-solving tool in the workup of suspected acute cholecystitis. Methods We queried our radiology information system database for cases in which SPECT/CT had been performed as part of the routine hepatobiliary technetium Tc 99m iminodiacetic acid studies done for the evaluation of acute cholecystitis. Fifty-three consecutive patients who had SPECT/CT after planar imaging were included. This cohort represents cases that were considered problematic by the initial interpreting physician on the basis of planar images. The planar and SPECT/CT images were retrospectively reviewed independently and separately by 2 experienced nuclear medicine specialists who evaluated the planar images for visualization of the gallbladder on a binary scale (yes or no) and rated their level of confidence on an ordinal scale(unsure, somewhat sure, and sure). Results Single-photon emission CT/CT would have led to change in the management for interpreter 1 in a total of 23 cases (41%), with change from normal to abnormal scan findings (28%) and from abnormal to normal scan findings (13%). Similarly, SPECT/CT would have led to change in the management for interpreter 2 in a total of 23 cases (43%), with change from normal to abnormal scan findings (13%) and from abnormal to normal scan findings (30%). Conclusions Although planar hepatobiliary scanning is usually sensitive and specific, there are occasionally problematic cases. In our experience, we found that the addition of SPECT/CT improved the interobserver agreement and may change management in patients with superimposed bowel activity and/or unusual gallbladder anatomy that can confound the planar interpretation.

This article describes how fire in the Earth system is investigated using charcoal fragments and charred particles. It reviews both the production of charcoal and charred particles, as well as the evolution of paleofire research. Descriptions of dispersal, recovery, sampling methods, and quantitative analyses are presented sequentially, with a focus on stratigraphic deposits, soil records, and archaeological sites. An overview of the recently developed Global Charcoal Database is provided, as are recommendations for potential areas of future research.

Salivary gland lesions discovered incidentally on various anatomic and molecular imaging modalities (-including PET-CT and SPECT-CT-) offer a clinical dilemma. The appropriate use of imaging techniques to diagnose a Warthin’s tumor would be of utility. Anatomical and functional imaging modalities have been used with variable success. The evaluation of a suspected Warthin’s tumor is challenging, each modality presenting with its benefits and limitations. No comprehensive review exists of the various ways to image Warthin’s tumor. This review would help imaging experts to find ways to diagnose Warthin’s tumors in difficult or indeterminate biopsies as well as cases where a biopsy is not indicated or not the first choice- for a variety of reasons. We propose to review different imaging techniques with the most recent advances, including PET-CT and SPECT-CT.

While the ultimate goal of health education interventions is to positively influence health status, more proximal indicators of success are changes in intermediate outcomes, or impact. Because health education interventions work through intermediate outcomes, the linkage to health status is often assumed to be at a conceptual or theoretical level. The term health education intervention strategy is a heuristic device used to conceptualize and organize a large variety of activities. There is a wide range of studies and reports in the literature that either test specific intervention strategies or report on larger health education efforts combining several strategies. This article organizes the discussion to focus on individual-, community-, and policy-level interventions. Mass communications are also considered, and the authors comment on program planning issues that cut across specific interventions at the individual, community, and policy levels. Eleven recommendations are offered for future health education intervention research.

Tc-99m labeled RBC scintigraphy is commonly employed in the evaluation of acute gastrointestinal bleeding. On Tc-99m RBC studies gastrointestinal bleeding is seen as an initial focus of increased radiotracer activity that on subsequent images increases in intensity and changes position in a pattern that conforms to segments of bowel. We report a case of a patient with multiple episodes of hematochezia that presented with lower gastrointestinal hemorrhage. A Tc-99m labeled RBC scan was performed and the findings suggested a GI bleed. However, subsequent angiography revealed prominent ileal varices simulating an acute bleed. Although most varices fill promptly and should not be misinterpreted as a focus of hemorrhage, slow filling varices can simulate an acute bleed and lead to a false positive interpretation.

Cardiac uptake of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) is frequently observed on FDG positron-emission tomography combined with computed tomography (PET-CT) performed for diagnosis, staging, and assessment of therapeutic response of lymphoma and solid cancers, despite careful patient preparation to limit myocardial glucose substrate utilisation. We illustrate the varied physiological patterns of cardiac FDG uptake, and show a spectrum of pathological conditions causing FDG uptake within myocardial and pericardial structures, due to clinically important benign and malignant diseases. Recognition and awareness of these various causes of FDG uptake in the heart, along with the appropriate use of correlative contrast-enhanced CT and magnetic resonance imaging (MRI) will facilitate correct interpretation.

Summary Current ambient ozone concentrations in the southeastern U.S.A. have the potential to affect carbon fixation rates and growth of forest tree species. In this study, loblolly pine saplings were exposed to ozone fumigation in open-top chambers during four growing seasons in the Piedmont of North Carolina, U.S.A. to study biochemical responses in pathways of carbon fixation and metabolism. The trees exhibited a significant decrease in needle photosynthetic rates proportional to the cumulative ozone exposure, decreasing by 50 % after 350 ppm - h (12-h summation). This decrease was correlated with a parallel decline in Rubisco activity. In contrast, increases in the activities of several enzymes linked to the degradative pathways of sugars were observed. The largest increase was observed in the activity of glucose-6phosphate dehydrogenase (65 % for 300 ppm - h). However, this marked increase and the slighter increases in phosphofructokinase and fumarase activities (about 25 %) showed a tendency to a further decline when the trees were exposed to higher cumulative ozone doses. Thus, current ambient ozone concentrations could lead progressively to biochemical disequilibrium within leaf cells with reduced production of assimilates and transient increased respiration.

Nuclear medicine has long played an important role in the noninvasive evaluation of known or suspected coronary artery disease. The development of single photon emission computed tomography (SPECT) led to improved assessments of myocardial perfusion, and the use of electrocardiographic gating made accurate measurements of ventricular wall motion, ejection fractions, and ventricular volumes possible. With the use of hybrid SPECT/computed tomography (CT) scanning systems, the cardiac functional parameters can be measured in a single imaging session. These recent advances in imaging technology have not only enhanced image quality but also improved diagnostic sensitivity and specificity in the detection of clinically relevant coronary artery disease. The CT-based attenuation maps obtained with hybrid SPECT/CT systems also have been useful for improving diagnostic accuracy. However, when attenuation correction and other advanced image data postprocessing techniques are used, unexpected artifacts may arise. The artifacts most commonly encountered are related to the characteristics either of the technology or of the patient. Thus, close attention to the details of acquisition protocols, processing techniques, and image interpretation is needed to ensure high diagnostic quality in myocardial perfusion studies.

Objective To determine the optimal anatomic coverage at CT that would provide the most accurate staging for patients with non-small cell lung cancer. Methods We reviewed lung cancer staging PET-CT scans and correlated them with staging chest CT scans performed within 50 days of the PET-CT study. There were 113 patients who underwent both studies within our time frame. We reviewed the results of subsequent imaging studies and surgical and biopsy procedures to determine the final stage for each patient. This study was approved by the local institutional review board. Results In 86 (76%) of 113 patients, staging by PET-CT and by CT from the lung apices through the lung bases was identical. PET-CT upstaged 21 patients (19%) compared with CT findings; in 13 of these patients the PET-CT noted disease that was either outside of the anatomic range of any lung cancer staging CT or was within the area scanned by CT, but was not evident by CT. In the other 8 upstaged patients, extending the anatomic scope of the CT scan to the supraclavicular region (5), adrenal glands (2) or abdomen (1) would have resulted in correct staging. Conclusions CT scanning from the supraclavicular region through the caudal adrenal glands improves the accuracy of CT staging of lung cancer compared with scanning from the lung apices through the lung bases. Anatomic coverage beyond the adrenal glands has a low yield for improved staging, at the cost of requiring administration of oral contrast to all patients. Summary To determine the optimal anatomic coverage at CT that would provide the most accurate staging for patients with non-small cell lung cancer, we reviewed lung cancer staging PET-CT scans and correlated them with staging chest CT scans performed within 50 days of the PET-CT study. CT scanning from the supraclavicular region through the caudal adrenal glands improves the accuracy of CT staging of lung cancer compared with scanning from the lung apices through the lung bases. Anatomic coverage beyond the adrenal glands has a low yield for improved staging, at the cost of requiring administration of oral contrast to all patients undergoing lung cancer staging.

At the UMC Utrecht, The Netherlands, we have constructed a prototype MRI accelerator. The prototype is a modified 6 MV Elekta (Crawley, UK) accelerator next to a modified 1.5 T Philips Achieva (Best, The Netherlands) MRI system. From the initial design onwards, modifications to both systems were aimed to yield simultaneous and unhampered operation of the MRI and the accelerator. Indeed, the simultaneous operation is shown by performing diagnostic quality 1.5 T MRI with the radiation beam on. No degradation of the performance of either system was found. The integrated 1.5 T MRI system and radiotherapy accelerator allow simultaneous irradiation and MR imaging. The full diagnostic imaging capacities of the MRI can be used; dedicated sequences for MRI-guided radiotherapy treatments will be developed. This proof of concept opens the door towards a clinical prototype to start testing MRI-guided radiation therapy (MRIgRT) in the clinic.

We report the case of a woman with non-small cell lung cancer (NSCLC) metastatic to the pancreas who underwent pancreatic resection followed by a significant disease-free interval. Resection of NSCLC metastases, other than those to the brain and adrenal gland, are rarely reported. We could not identify any other cases of pancreatic metastasis resection in the literature. This case proves, in principle, that resection of solitary metastatic lesions in certain clinical conditions can be improved regardless of location.

Background: Positron emission tomography (PET) is more accurate than computed tomography (CT) in staging and restaging of lymphoma, but both are considered necessary. Increasingly, PET is carried out with a low-dose CT scan. Many patients undergo both PET/CT and standard diagnostic CT. The clinical utility of performing both studies in patients with lymphoma was evaluated. Patients and methods: Patients with lymphoma who underwent concurrent PET/CT and diagnostic CT (a scan pair) were identified, and findings detected in either scan but not both were documented. Discrepancies were considered significant if they were related to either lymphoma or another disease process which potentially required intervention. Results: Eighty-seven scan pairs were identified. PET/CT detected additional lesions over diagnostic CT in 30 patients, of which 11 demonstrated increased clinical stage. Lymphoma therapy changed based on PET/CT in two patients, and one occult rectal cancer was detected. In contrast, diagnostic CT detected five relevant findings, including two incidental findings (venous thrombosis) and three patients with splenic lesions, none of which could be confirmed as lymphoma. No patient had change of stage or lymphoma therapy based on diagnostic CT. Conclusion: In our series, diagnostic CT did not add value to staging or restaging of lymphoma when carried out concurrently with PET/CT.

We report on a 55-year-old woman with suspected primary hyperparathyroidism who underwent dual phase Tc-99m sestamibi parathyroid imaging. Symmetric, patchy activity in the neck and shoulders was localized to low attenuation areas on integrated SPECT/CT and attributed to uptake in brown adipose tissue (BAT). Focal uptake in the anterior thorax on SPECT images, which potentially may have been misinterpreted as ectopic parathyroid tissue, was demonstrated on SPECT/CT as uptake in BAT. Recognition of this pattern on parathyroid SPECT/CT scintigraphy may avoid false positive reports. Our case provides further evidence that in addition to F-18 FDG, I-123 MIBG, and Tc-99m tetrofosmin, Tc-99m sestamibi may also accumulate in BAT.

Forty patients with acute onset renal colic were studied using technetium-99m DTPA renal scintigraphy. Thirty-two were found to have varying degrees of obstruction. In the obstructed group the level was determined by the scan alone in 24 of 32 cases (75%). When the analysis included an abdominal radiograph, the level of obstruction was ascertained in 29 of 32 cases (91%). A delayed nephrogram, as evidenced by an "empty renal pelvis sign" at 5 minutes, was observed in all but one of the cases of obstruction (97%). Delayed clearance of activity from the pyelocalyceal system or ureter was also seen in 97%. In all cases of obstruction either one or both of these signs were observed. However, delayed clearance was found to be a nonspecific finding and was noted in 25% of nonobstructed cases. The finding of the "empty renal pelvis sign" at 5 minutes was found to be specific and was not seen in the nonobstructed group. The authors conclude that radionuclide renal scanning is an effective method for evaluating selected patients with suspected renal colic.

A small number of patients with angiosarcoma present each year, even fewer of whom have their primary origin site in the lungs. As such, specific treatments are not well defined for this tumor type. We report that the combination of gemcitabine and docetaxel may be an effective regimen for the treatment of angiosarcoma, as illustrated by the complete radiological response observed. In this case report, we review the clinical characteristics, prevalence and treatment options for angiosarcoma. In particular, we review the potential pitfalls and important attributes that should inform diagnosis.

A teenage girl presentedwith new onset of bilateral upper extremity numbness and paresthesias. The rest of the clinical history and neurological examination was unremarkable. A magnetic resonance imaging (MRI) study of the brain and cervical spine obtained to evaluate for demyelinating disease demonstrated a normal brain and cervical cord, but an incidental T2 hyperintense lesion within the rightpterygoidmuscleswasnoted.Onfurther consultation with the otolaryngology department, the patient stated that she had not experiencedanysensationofamass, and results froma focusedotolaryngologicexamination were also normal. A dedicated fifth cranial nerveMRI examination performed to better characterize the lesion revealed a well-defined, lobulated T2 hyperintense lesion within the right pterygoid muscles without mass effect, adjacent edema, or other invasive features (Figure, A). Therewas a small focus of signal void on the T2-weighted images, suspicious for tiny calcification. On gadolinium administration, there was sequential increasedenhancementon thepostcontrastT1-weightedaxial images (Figure, B and C). Further imaging workup with single-proton emission computed tomography-CT (SPECT-CT) using technetium Tc 99m–labeled red blood cells (RBCs) demonstrated increased tracer pooling within the lesion (Figure, D). Quiz at jamaotolaryngology.com A B C D

The author describes a project whose aim was to determine the preferred method for the US Air Force to use in remediating or disposing of stockpiled soil, contaminated with petroleum, oil, and/or lubricant (POL), at a remote Air Force base (AFB) in Alaska. This was accomplished by using the hierarchy decision process (HDP). The author explains the processes of formulating an expert panel, generating the primary criteria that affect the decision, and deriving the relative importance of the criteria and alternatives. In solving the hierarchy for the preferred method, both bottom-up and top-down aggregation approaches were used. The solution of the HDP indicates that vapor extraction is the preferred method to treat stockpiled POL-contaminated soil at Shemya AFB. >

e17509 Background: Esophageal uptake of FDG is commonly seen in patients with non-small cell lung cancer (NSCLC), but the relationship of the uptake to radiation esophagitis has not been delineated...