HETEAC: The Aerosol Classification Model for EarthCARE

We introduce the Hybrid End-To-End Aerosol Classification (HETEAC) model for the upcoming EarthCARE mission. The model serves as the common baseline for development, evaluation, and implementation of EarthCARE algorithms. It shall ensure the consistency of different aerosol products from the multi-instrument platform as well as facilitate the conform specification of broad-band optical properties necessary for the EarthCARE radiative closure efforts. The hybrid approach ensures the theoretical description of aerosol microphysics consistent with the optical properties of various aerosol types known from observations. The end-to-end model permits the uniform representation of aerosol types in terms of microphysical, optical and radiative properties

Verbesserung der chirurgischen Therapieplanung gastrointestinaler Tumoren durch neue Techniken der Endosonographie und Staging-Laparoskopie

Das präoperative Staging ist von eminenter Bedeutung für die Planung einer differenzierten chirurgischen Therapiestragie für gastrointestinale Tumoren. Die endoskopische Sonographie hat sich inzwischen als das Verfahren mit der höchsten Genauigkeit in der lokoregionären Ausbreitungdiagnostik von Tumoren des Ösophagus, Magens, Pankreas und Kolorektums etabliert. Es bestehen jedoch verschiedene Limitationen, die den klinischen Stellenwert der bisher verfügbaren endosonographischen Techniken einschränken. Eine wesentliche Limitation der Endosonographie ist die ungenügende Sensitivität für Fernmetastasen. Ziel dieser Arbeit war es, die Ergebnisse des präoperativen Staging gastroinestinaler Tumoren durch innovative endosonographische Verfahren und die kombinierte laparoskopische Diagnostik mittels Staging-Laparoskopie und laparoskopischer Sonographie zu optimieren. Im Hinblick auf eine Verbesserung der lokoregionären Ausbreitungsdiagnostik wurden verschiedene neue diagnostische und interventionelle endosonographische Techniken entwickelt und klinisch evaluiert. Für die differenzierte Abklärung von Kurabilität und Resektabilität gastrointestinaler Tumoren im Rahmen der Staging-Laparoskopie wurde ein systematischer Untersuchungs-algorhythmus für die kombinierte laparoskopische Diagnostik etabliert. Die Ergebnisse der Staging-Laparoskopie im Vergleich zum konventionellen Staging wurden bei mehr als 600 Patienten prospektiv dokumentiert und der Stellenwert für die chirurgische Therapieplanung analysiert. Die Resultate unserer Untersuchungen demonstrieren, daß das lokoregionäre Staging gastrointestinaler Tumoren durch neue endosonographische Techniken wie die Minisonden-Endsonographie, 3D-Endosonographie und endosonographische Punktionsverfahren weiter verbessert werden kann. Als sensitive Methode für die Diagnostik intraabdomineller Fernmetasen stellt die Laparoskopie eine ideale Ergänzung des lokoregionären endosonographischen Staging dar. Der kombinierte Einsatz dieser minimal invasiven Techniken ermöglicht eine verbesserte präoperative Beurteilung der Resektabilität und Kurabilität gastrointestinaler Tumoren. Hierdurch kann die Planung einer differenzierten chirurgischen Tumortherapie optimiert werden.Accurate preoperative staging of gastrointestainal tumors is essential for planning of surgical therapy. Endoscopic ultrasound has improved evaluation of locoregional tumor spread significantly. However, there are some technical problems that limit the clinical value of endoscopic ultrasound with currently available techniques. The most important limitations is the insatisfactory sensitivity for metastatic disease. We have developed new technologies for endoscopic ultrasound that can overcome most of the problems encountered with conventional endoscopic ultrasound. Furthermore a staging algorithm including the use of laparoscopy and laparoscopic ultrasound was evaluated to enhance the sensitivity for distant metastases. The results of our studies show that innovative endoscopic techniques, i.e. miniprobe ultrasonography, 3D endoscopic ultrasound and endoscopic ultrasound guided can improve the accuray of endoscopic ultrasound in the staging of gastrointestinal cancers. Laparoscopy and laparoscopic ultrasonography are ideal adjunct to endoscopic ultrasound, because both increase the sensitivity for distant metastases significantly. Combined staging with innovative endoscopic techniques and staging laparoscopy facilitates planning of surgery and multimodal therapy

Augmenting intraoperative 3D ultrasound with preoperative models for navigation in liver surgery

Abstract. Organ deformation between preoperative image data and the patient in the OR is the main obstacle for using surgical navigation systems in liver surgery. Our approach is to provide accurate navigation via intraoperative 3D ultrasound. These ultrasound data are augmented with preoperative anatomical models and planning data as an important additional orientation aid for the surgeon. We present an overview of the whole ultrasound navigation system as well as an approach for fast intraoperative non-rigid registration of the preoperative models to the ultrasound volume. The registration method is based on the vessel center lines and consists of a combination of the Iterative Closest Point algorithm and multilevel B-Splines. Quantitative results for three different patients are presented.

Preoperative Evaluation of Colorectal Neoplasms by Colonoscopic Miniprobe Ultrasonography

OBJECTIVE: To investigate the value of colonoscopic miniprobe ultrasonography for preoperative staging of colorectal neoplasms. SUMMARY BACKGROUND DATA: Endoscopic ultrasonography is the most accurate technique for staging colorectal cancer. However, limitations of this technique include the inability to examine stenotic tumors and the difficulty of reaching tumors proximal to the rectum. METHODS: Miniprobe ultrasonography (12.5 MHz) was performed in 63 patients with tumors of the colon or rectum. The results of imaging were compared with endoscopic assessment of the lesions and histopathologic findings of the resected specimens. RESULTS: Miniprobe ultrasonography allowed high-resolution imaging of colorectal tumors during routine colonoscopy. The infiltration depth was correctly classified in 22 adenoma, 3 T1, 10 T2, and 22 T3 or T4 tumors. The accuracy for tumors of the rectum and colon was 86% and 92%, respectively (overall accuracy 90%). The small diameter of the probe allowed examination of 21 stenotic tumors with an accuracy of 86%. Miniprobe ultrasonography revealed carcinoma in 5 of 30 broad-based polyps, although adenomas were diagnosed by endoscopy. Correct assessment of lymph node involvement was obtained in 47 of 55 patients. Based on the findings of miniprobe ultrasonography, management was modified in 7 of the 63 patients. CONCLUSIONS: These preliminary results show that miniprobe ultrasonography improves preoperative staging of stenotic rectal cancer and colonic tumors. This technique can be easily performed during routine colonoscopy and may have considerable impact on surgical therapy

A New Class of Distance Measures for Registration of Tubular Models to Image Data

Abstract. In some registration applications additional user knowledge is available, which can improve and accelerate the registration process, especially for non-rigid registration. This is particularly important in the transfer of pre-operative plans to the operating room, e.g. for navigation. In case of tubular structures, such as vessels, a geometric representation can be extracted via segmentation and skeletonization. We present a new class of distance measures based on global filter kernels to compare such models efficiently with image data. The approach is validated in a non-rigid registration application with Powerdoppler ultrasound data.

An experimental study to evaluate the fluobeam 800 imaging system for fluorescence-guided lymphatic imaging and sentinel node biopsy

Visualization of the lymphatic system is challenging. Lymphatic imaging is a crucial diagnostic tool for benign and malignant lymphatic pathologies. Fluorescence-guided imaging allows selective lymphatic mapping and sentinel lymph node (SLN) identification. There are a few fluorescence systems, but some drawbacks remain due to technical and ergonomic aspects. The aim of this study was to evaluate the feasibility of the new Fluobeam 800 imaging system. After approval by the ethics committee, the system was evaluated for lymphography and SLN biopsy in an animal model. Five pigs each with 4 lymph node (LN) stations (n = 20 LN stations) were subjected to lymphatic imaging using indocyanine green (ICG). Additionally, the use of ICG was compared with ICG adsorbed to human serum albumin (ICG-HSA). Lymphatic vessels and SLN identification rates were measured. After injection, a clear fluorescence signal of the lymphatic vessels was visualized leading to the LN station. Overall, ICG fluorescence imaging identified a mean of 2.0 lymphatic vessels and 1.1 (range = 1-2) SLN in 20 of 20 LN stations. Reverse lymphography was feasible. A clinical difference in resolution was not detected between use of ICG-HSA and ICG. This is the first study analyzing the feasibility of the Fluobeam 800 imaging system allowing transcutaneous real-time imaging. It enables detection of the SLN by fluorescence retention with increased detection depth and resolution. After fixation to the ceiling, the ergonomics advanced for simultaneous field navigation and dissection. The new system can be applied for lymphatic imaging for lympatico-reconstructive surgery and SLN biopsy

Validation of the Aeolus L2B Rayleigh winds and ECMWF short‐range forecasts in the upper troposphere and lower stratosphere using Loon super pressure balloon observations

The novel Aeolus satellite, which carries the first Doppler wind lidar providing profiles of horizontal line‐of‐sight (HLOS) winds, addresses a significant gap in direct wind observations in the global observing system. The gap is particularly critical in the tropical upper troposphere and lower stratosphere (UTLS). This article validates the Aeolus Rayleigh–clear wind product and short‐range forecasts of the European Centre for Medium‐Range Weather Forecasts (ECMWF) with highly accurate winds from the Loon super pressure balloon network at altitudes between 16 and 20 km. Data from 229 individual balloon flights are analysed, applying a collocation criterion of 2 hr and 200 km. The comparison of Aeolus and Loon data shows systematic and random errors of -0.31 and 6.37 m·s-1, respectively, for the Aeolus Rayleigh–clear winds. The horizontal representativeness error of Aeolus HLOS winds (nearly the zonal wind component) in the UTLS ranges from 0.6–1.1 m·s-1 depending on the altitude. The comparison of Aeolus and Loon datasets against ECMWF model forecasts suggests that the model systematically underestimates the HLOS winds in the tropical UTLS by about 1 m·s-1. While Aeolus winds are currently considered as point winds by the ECMWF data assimilation system, the results of the present study demonstrate the need for a more realistic HLOS wind observation operator for assimilating Aeolus winds