Diagnostic modalities for distant metastasis in head and neck squamous cell carcinoma: Are we changing life expectancy?

Objectives/Hypothesis: To determine if the various imaging modalities for distant metastasis (DM) diagnosis alters life expectancy in head and neck squamous cell carcinoma (HNSCC). Study Design: Retrospective. Methods: One hundred seventy patients (mean age, 59.1 years; male:female, 135:35) with HNSCC who developed DM were reviewed. The main outcome measures were the method of DM diagnosis and time from DM diagnosis to death while controlling for clinical parameters (age, gender, tobacco status, primary tumor site, initial TNM classification, number and site of DM, administration of palliative chemotherapy). Results: Tumor subsites were: 40 oral cavity, 75 oropharynx, 36 larynx, 10 hypopharynx, one nasopharynx, and eight unknown primary. Of the patients, 16.5% (28/170) had distant metastasis at presentation; the remaining 142 patients were diagnosed with DM at a median of 324 days from diagnosis. Although patients diagnosed with DM by positron‐emission tomography (PET) scan were more likely to have multiple DM sites ( P = .0001), there were no differences in life expectancy in patients who were diagnosed with or without PET scan (median, 185 vs. 165 days, P = .833). There were no differences in life expectancy based on age, gender, site of primary tumor, or number/site of DM. The use of palliative chemotherapy resulted in a significantly longer life expectancy (median, 285 vs. 70 days; P = .001). Conclusions: Although a PET scan is more likely to diagnose multiple DM sites, there was no difference in life expectancy based on imaging modality. Patients who are symptomatic from their distant metastasis have a worse life expectancy, and palliative chemotherapy was able to increase life expectancy, even in patients who were symptomatic from the distant metastasis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92128/1/23264_ftp.pd

Spatial mapping of photovoltage and light-induced displacement of on-chip coupled piezo/photodiodes by Kelvin probe force microscopy under modulated illumination

In this work, a silicon photodiode integrated with a piezoelectric membrane is studied by Kelvin probe force microscopy (KPFM) under modulated illumination. Time-dependent KPFM enables simultaneous quantification of the surface photovoltage generated by the photodiode as well as the resulting mechanical oscillation of the piezoelectric membrane with vertical atomic resolution in real-time. This technique offers the opportunity to measure concurrently the optoelectronic and mechanical response of the device at the nanoscale. Furthermore, time-dependent atomic force microscopy (AFM) was employed to spatially map voltage-induced oscillation of various sizes of piezoelectric membranes without the photodiode to investigate their position-and size-dependent displacement.</p

Human Detection and Classification of Landing Sites for Search and Rescue Drones

Search and rescue is often time and labour intensive. We present a system to be used in drones to make search and rescue operations more effective. The system uses a drone downward facing camera to detect people and to evaluate potential sites as being safe or not for the drone to land. Histogram of Oriented Gradients (HOG) features are extracted and a Support Vector Machine (SVM) is used as classifier. Our results show good performance on classifying frames as containing people (Sensitivity > 78%, Specificity > 83%), and distinguishing between safe and dangerous landing sites (Sensitivity > 87%, Specificity > 98%)

Increased Carotid Intima-Media Thickness as a Predictor of the Presence and Extent of Abnormal Myocardial Perfusion in Type 2 Diabetes

OBJECTIVE - identification of asymptomatic patients with type 2 diabetes at increased risk for coronary artery disease (CAD) remains a challenge. We evaluated the Potential of carotid intima-media thickness (CIMT) for prediction of abnormal myocardial perfusion in this population. RESEARCH DESIGN AND METHODS- CIMT and SPECT myocardial perfusion imaging were assessed in 98 asymptomatic patients with type 2 diabetes. An increased CIMT was defined as >= 75th percentile of reference values. RESULTS - increased CIMT was an independent predictor of the extent of abnormal perfusion (P < 0.001). In patients with increased CIMT as compared with patients with normal CIMT, abnormal perfusion (75 vs. 9%) and severely abnormal perfusion (28 vs. 3%) were observed more frequently. CONCLUSIONS - increased CIMT was significantly related to the presence and extent of abnormal myocardial perfusion. Assessment of CIMT may be useful to identify asymptomatic patients with type 2 diabetes at higher risk for CAD.Diabetes mellitus: pathophysiological changes and therap

Myocardial perfusion scintigraphy before and after cardioversion for atrial fibrillation: Recovery of quantitative parameters

Cardiovascular Aspects of Radiolog

Multicentre quantitative Ga-68 PET/CT performance harmonisation

Purpose Performance standards for quantitative F-18-FDG PET/CT studies are provided by the EANM Research Ltd. (EARL) to enable comparability of quantitative PET in multicentre studies. Yet, such specifications are not available for Ga-68. Therefore, our aim was to evaluate Ga-68-PET/CT quantification variability in a multicentre setting. Methods A survey across Dutch hospitals was performed to evaluate differences in clinical Ga-68 PET/CT study protocols. Ga-68 and F-18 phantom acquisitions were performed by 8 centres with 13 different PET/CT systems according to EARL protocol. The cylindrical phantom and NEMA image quality (IQ) phantom were used to assess image noise and to identify recovery coefficients (RCs) for quantitative analysis. Both phantoms were used to evaluate cross-calibration between the PET/CT system and local dose calibrator. Results The survey across Dutch hospitals showed a large variation in clinical Ga-68 PET/CT acquisition and reconstruction protocols. Ga-68 PET/CT image noise was below 10%. Cross-calibration was within 10% deviation, except for one system to overestimate F-18 and two systems to underestimate the Ga-68 activity concentration. RC-curves for F-18 and Ga-68 were within and on the lower limit of current EARL standards, respectively. After correction for local Ga-68/F-18 cross-calibration, mean Ga-68 performance was 5% below mean EARL performance specifications. Conclusions Ga-68 PET/CT quantification performs on the lower limits of the current EARL RC standards for F-18. Correction for local Ga-68/F-18 cross-calibration mismatch is advised, while maintaining the EARL reconstruction protocol thereby avoiding multiple EARL protocols