FDG-PET in HIV-Positive Patient with Extranodal Diffuse Large B-Cell Lymphoma.

Extranodal diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease process and an aggressive form of non-Hodgkin's lymphoma. We present a case of multiorgan involvement of DLBCL in a patient with documented risk factors, including [ 18 F] fluorodeoxyglucose positron emission tomography/magnetic resonance imaging findings highlighting striking perineural spread involving intracranial and extracranial segments of the bilateral trigeminal nerves.

Stationary and portable multipollutant monitors for high-spatiotemporal-resolution air quality studies including online calibration.

The distribution and dynamics of atmospheric pollutants are spatiotemporally heterogeneous due to variability in emissions, transport, chemistry, and deposition. To understand these processes at high spatiotemporal resolution and their implications for air quality and personal exposure, we present custom, low-cost air quality monitors that measure concentrations of contaminants relevant to human health and climate, including gases (e.g., O3, NO, NO2, CO, CO2, CH4, and SO2) and size-resolved (0.3-10 µm) particulate matter. The devices transmit sensor data and location via cellular communications and are capable of providing concentration data down to second-level temporal resolution. We produce two models: one designed for stationary (or mobile platform) operation and a wearable, portable model for directly measuring personal exposure in the breathing zone. To address persistent problems with sensor drift and environmental sensitivities (e.g., relative humidity and temperature), we present the first online calibration system designed specifically for low-cost air quality sensors to calibrate zero and span concentrations at hourly to weekly intervals. Monitors are tested and validated in a number of environments across multiple outdoor and indoor sites in New Haven, CT; Baltimore, MD; and New York City. The evaluated pollutants (O3, NO2, NO, CO, CO2, and PM2.5) performed well against reference instrumentation (e.g., r = 0.66-0.98) in urban field evaluations with fast e-folding response times (≤1 min), making them suitable for both large-scale network deployments and smaller-scale targeted experiments at a wide range of temporal resolutions. We also provide a discussion of best practices on monitor design, construction, systematic testing, and deployment.

Field and Laboratory Evaluations of the Low-Cost Plantower Particulate Matter Sensor.

Due to the rapid development of low-cost air-quality sensors, a rigorous scientific evaluation has not been conducted for many available sensors. We evaluated three Plantower PMS A003 sensors when exposed to eight particulate matter (PM) sources (i.e., incense, oleic acid, NaCl, talcum powder, cooking emissions, and monodispersed polystyrene latex spheres under controlled laboratory conditions and also residential air and ambient outdoor air in Baltimore, MD). The PM2.5 sensors exhibited a high degree of precision and R2 values greater than 0.86 for all sources, but the accuracy ranged from 13 to >90% compared with reference instruments. The sensors were most accurate for PM with diameters below 1 µm, and they poorly measured PM in the 2.5-5 µm range. The accuracy of the sensors was dependent on relative humidity (RH), with decreases in accuracy at RH > 50%. The sensors were able to produce meaningful data at low and high temperatures and when in motion, as it would be if utilized for outdoor or personal monitoring applications. It was most accurate in environments with polydispersed particle sources and may not be useful in specialized environments or experiments with narrow distributions of PM or aerosols with a large proportion of coarse PM.

Percutaneous Gastrostomy Device for the Treatment of Class II and Class III Obesity: Results of a Randomized Controlled Trial.

OBJECTIVES: The AspireAssist System (AspireAssist) is an endoscopic weight loss device that is comprised of an endoscopically placed percutaneous gastrostomy tube and an external device to facilitate drainage of about 30% of the calories consumed in a meal, in conjunction with lifestyle (diet and exercise) counseling. METHODS: In this 52-week clinical trial, 207 participants with a body-mass index (BMI) of 35.0-55.0 kg/m2 were randomly assigned in a 2:1 ratio to treatment with AspireAssist plus Lifestyle Counseling (n=137; mean BMI was 42.2±5.1 kg/m2) or Lifestyle Counseling alone (n=70; mean BMI was 40.9±3.9 kg/m2). The co-primary end points were mean percent excess weight loss and the proportion of participants who achieved at least a 25% excess weight loss. RESULTS: At 52 weeks, participants in the AspireAssist group, on a modified intent-to-treat basis, had lost a mean (±s.d.) of 31.5±26.7% of their excess body weight (12.1±9.6% total body weight), whereas those in the Lifestyle Counseling group had lost a mean of 9.8±15.5% of their excess body weight (3.5±6.0% total body weight) (P<0.001). A total of 58.6% of participants in the AspireAssist group and 15.3% of participants in the Lifestyle Counseling group lost at least 25% of their excess body weight (P<0.001). The most frequently reported adverse events were abdominal pain and discomfort in the perioperative period and peristomal granulation tissue and peristomal irritation in the postoperative period. Serious adverse events were reported in 3.6% of participants in the AspireAssist group. CONCLUSIONS: The AspireAssist System was associated with greater weight loss than Lifestyle Counseling alone.

Pulmonary embolism: role of ventilation-perfusion scintigraphy.

The evaluation for pulmonary embolism in the emergency setting has many challenges. Patients often present with symptoms that are nonspecific. Emergency Department physicians utilize their own subjective judgment or objective clinical algorithms, such as the Wells Score to assess the likelihood of the patient having PE. Other techniques, such as D-dimer assays and Doppler ultrasound leg studies for deep venous thrombosis are very useful, as well. Ventilation-perfusion lung scans and computed tomography pulmonary angiography are both available in most institutions. However, factors such as sensitivity or specificity, overnight availability, radiation exposure, and comfort with interpretation criteria play a role in deciding which procedure should be used. Relative merits of both the procedures will be discussed.

Klippel-Trénaunay syndrome (KTS) evaluated with bone and labeled RBC scintigraphy.

This is a case of a 4-year-old female child with gross left lower extremity deformity detected at birth, including a giant cutaneous hemangioma from flank to foot. She was found to have no other associated abnormalities and was diagnosed with Klippel-Trénaunay syndrome. This is a rare entity and literature regarding use of radionuclide imaging techniques to evaluate this is scarce. We present here bone and red cell scans performed to evaluate whether there was osseous involvement or only soft tissue disease, which showed classic signs of this condition. Patient photographs also show the syndrome's typical appearance.

Photomultiplier tube artifacts on 67Ga-citrate imaging caused by loss of correction floods due to an off-peak status of one head of a dual-head γ-camera.

UNLABELLED: γ-cameras use flood-field corrections to ensure image uniformity during clinical imaging. A loss or corruption of the correction data of one head of a dual-head camera can result in an off-peak artifactual appearance. We present our experience with the occurrence of such an incident on a (67)Ga scan. METHODS: A patient was referred for a whole-body (67)Ga scan to evaluate for causes of neutropenic fever. Whole-body planar and static images of the head, chest, abdomen, pelvis, and lower extremities in multiple projections were obtained. RESULTS: Whole-body images showed decreased image quality on the anterior view obtained with detector 1 and an unremarkable posterior image obtained with detector 2. A problem with detector 2 was suspected, and additional static images were obtained after rotation of the detector heads. The posterior images taken with detector 1 showed photomultiplier tube outlines. The anterior images taken with detector 2 showed improved count and image quality. It was later found that the uniformity map for detector 2 had been lost and that this software malfunction led to the resulting imaging problem. CONCLUSION: When artifacts with an off-peak appearance are seen on scintigraphic images, evaluation of possible causes should include not only isotope window settings but also an incorrect or corrupted uniformity map.

Planar ventilation-perfusion imaging for pulmonary embolism: the case for "outcomes" medicine.

Single-photon emission computed tomography (SPECT) has been a significant advancement in scintigraphy, impacting many areas of diagnosis. It has begun to find use in ventilation-perfusion (V/Q) scintigraphy. However, its utility has been limited in the United States because of a lack of an optimal and Food and Drug Administration-approved SPECT ventilatory agent. Although SPECT V/Q can show more and smaller mismatches than planar studies, there is persistent debate regarding the clinical significance of these smaller pulmonary emboli (PE); they may be neither clinically significant nor require treatment. Available data suggest that planar V/Q, SPECT V/Q, and computed tomographic pulmonary angiography (CTPA) have similar false-negative rates and thus have a similar impact on outcomes. In most cases, emergency department physicians are the first to encounter patients who may have PE, and they frequently use an imaging study as part of the evaluation. We discuss the rational for triaging patients to different imaging modalities with the use of chest radiography and the strengths and weaknesses of each modality. Detailed anatomy is an advantage of CTPA, breast radiation dose is reduced with scintigraphy, and imaging is quicker and more detailed with SPECT. We also review planar and SPECT V/Q and CTPA from the differing vantage points of diagnostic accuracy vs patient outcomes. Whatever modality their patients require, physicians can be confident that they are all similarly efficacious at diagnosing clinically relevant emboli.

Successful and safe implementation of a trinary interpretation and reporting strategy for V/Q lung scintigraphy.

UNLABELLED: For the past 4 decades, ventilation-perfusion (V/Q) scan interpretation for pulmonary embolism (PE) was performed using probability-based assessments, which were neither well-received nor well-understood by many clinicians. Recently, we combined normal, very low probability, and low-probability interpretations in emergency department patients and found a false-negative (FN) rate of 1.2% on follow-up. Afterward, we transitioned to a new trinary interpretative strategy: no PE, PE present, and nondiagnostic. In this series, we compared the outcomes of the traditional and trinary interpretative strategies. METHODS: We retrospectively identified all patients undergoing V/Q scans for the 1 year straddling the shift in interpretive strategy, with traditional interpretation being used between September 18, 2008, and March 17, 2009, and trinary interpretation being used between March 18, 2009, and September 17, 2009. A FN study was defined as development of deep vein thrombosis or PE within 3 months after a negative baseline evaluation. RESULTS: The traditional interpretation group included 208 male patients (27%) and 570 female patients (73%), with a mean age (±SD) of 50.9 ± 18.4 years. These interpretations (n = 778) were high probability in 4.9% (38), intermediate probability in 5% (39), low probability in 59.5% (463), very low probability in 17.2% (134), and normal in 13.4% (104). The trinary interpretation group included 181 male patients (27%) and 483 female patients (73%), with a mean age of 50.0 ± 18.5 years. These interpretations (664) were positive in 8.4% (56), negative in 88.1% (585), and nondiagnostic in 3.5% (23). The FN rate was 1.14% (8/701; 7 deep vein thrombosis and 1 PE) for pooled normal, very low probability, and low probability in traditional interpretations versus 1.5% (9/585, 5 deep vein thrombosis and 4 PE) in trinary interpretations (P = 0.63). The individual FN rates for the normal, very low probability, and low-probability groups were 0.0%, 0.75%, and 1.51%, respectively (P = 0.36 for normal vs. low probability). Pediatric subgroup analysis showed 19 traditional interpretations: 5.3% high (1); 0 intermediate; and 94.7% (18) low probability, very low probability, and normal. 20 trinary interpretations were positive in 10% (2), nondiagnostic in 5% (1), and negative in 85% (17), with no FNs using either strategy. CONCLUSION: A simplified trinary interpretation strategy for V/Q lung scintigraphy provides outcomes similar to traditional probability assessments and facilitates clear communication.

Temporal exposure of cryptic collagen epitopes within ischemic muscle during hindlimb reperfusion.

Chronic limb-threatening ischemia is a devastating disease with limited surgical options. However, inducing controlled angiogenesis and enhancing reperfusion holds therapeutic promise. To gain a better understanding of the mechanisms that contribute to limb reperfusion, we examined the temporal biochemical and structural changes occurring within the extracellular matrix of ischemic skeletal muscle. Both the latent and active forms of MMP-2 and -9 significantly increased during the active phase of limb reperfusion. Moreover, small but significant alterations in tissue inhibitors of metalloproteinase levels also occurred during a similar time course, consistent with a net increase in extracellular matrix remodeling. This temporal increase in MMP activity coincided with enhanced exposure of the unique HU177 cryptic collagen epitope. Although the HUIV26 cryptic collagen epitope has been implicated in angiogenesis, little is known concerning such epitopes within ischemic muscle tissue. Here, we provide the first evidence that a functionally distinct cryptic collagen epitope (HU177) is temporally exposed in ischemic muscle tissue during the active phase of reperfusion. Interestingly, the exposure of the HU177 epitope was greatly diminished in MMP-9 null mice, corresponding with significantly reduced limb reperfusion. Therefore, the regulated exposure of a unique cryptic collagen epitope within ischemic muscle suggests an important role for collagen remodeling during the active phase of ischemic limb reperfusion.