• PURPOSE: To compare biometry performed by an enhanced version of dual beam partial coherence interferometry and applanation ultrasound in a prospective study of 85 cataract eyes to improve refractive outcome of cataract surgery due to a more accurate calculation of intraocular lens power. • METHODS: The SRK II formula using ultrasound biometry data was employed. Three months after surgery, partial coherence interferometry biometry was repeated and refractive outcome was determined. Preoperative partial coherence interferometry biometry data were used to determine the refractive power of the intraocular lenses retrospectively and to calculate the possible refractive outcome. • RESULT: Precision of partial coherence interferometry biometry was more than 10 times better than that of ultrasound. Therefore, the possible mean absolute error for postoperative refraction achieved with partial coherence interferometry biometry was 0.49 diopters (compared with 0.67 diopters with ultrasound biometry), resulting in an improvement of 27%. Axial eye length measured with the two techniques differed by a mean of 460 μm. The difference in lens thickness measured with partial coherence interferometry and ultra-sound significantly correlated with cataract grade. A mean shortening of 120 μm of axial eye length following cataract surgery was also detected by partial coherence interferometry. • CONCLUSIONS: The enhanced version of partial coherence interferometry offers biometry with un, precedented precision (<10 μm) and resolution (~12 μm), therefore improving the refractive outcome in cataract surgery. This noninvasive technique provides a high degree of comfort for the patient, with no need for local anesthesia or pupil dilation and minimized risk of corneal infection.

Partial Coherence Interferometry: A Novel Approach to Biometry in Cataract Surgery

New developments in MRI for target volume delineation in radiotherapy MRI is being increasingly used in oncology for staging, assessing tumour response and also for treatment planning in radiotherapy. Both conformal and intensity-modulated radiotherapy requires improved means of defining target volumes for treatment planning in order to achieve its intended benefits. MRI can add to the radiotherapy treatment planning (RTP) process by providing excellent and improved characterization of soft tissues compared with CT. Together with its multiplanar capability and increased imaging functionality, these advantages for target volume delineation outweigh its drawbacks of lacking electron density information and potential image distortion. Efficient MR distortion assessment and correction algorithms together with image co-registration and fusion programs can overcome these limitations and permit its use for RTP. MRI developments using new contrast media, such as ultrasmall superparamagnetic iron oxide particles for abnormal lymph node identification, techniques such as dynamic contrast enhanced MRI and diffusion MRI to better characterize tissue and tumour regions as well as ultrafast volumetric or cine MR sequences to define temporal patterns of target and organ at risk deformity and variations in spatial location have all increased the scope and utility of MRI for RTP. Information from these MR developments may permit treatment individualization, strategies of dose escalation and image-guided radiotherapy. These developments will be reviewed to assess their current and potential use for RTP and precision high dose radiotherapy. (C) 2006 The British Institute of Radiology.

New developments in Mill for target volume delineation in radiotherapy

Purpose Many studies comparing external-beam therapy (EBT) and brachytherapy (BT) are biased because advanced EBT is compared with conventional BT. This study compares high-tech EBT against high-tech BT. Methods and Materials Nine patients were selected with locally advanced cervix cancer, representing typical clinical situations according to initial tumor extension and response after EBT. Patients were treated either with intracavitary, combined interstitial/intracavitary, or complex interstitial BT. Gross tumor volume, high-risk clinical target volume (CTV), intermediate-risk CTV, bladder, rectum, and sigmoid were delineated. Magnetic resonance–guided BT planning was manually optimized with respect to organ dose limits. Margins (3 and 5 mm) were added to BT CTVs to construct planning target volumes (PTVs) for EBT. Inversely planned EBT with photons (IMRT) and protons (IMPT) was challenged to deliver the highest possible doses to PTVs while respecting D 1cc and D 2cc limits from BT, assuming the same fractionation (4 × 7 Gy). The D90 for target structures and normal tissue volumes receiving fractionated doses between 3 and 7 Gy were compared. Results High-risk CTV doses depended on the clinical situation and radiation quality. If IMRT was limited to D 2cc and D 1cc from BT, the D90 for high-risk PTV and intermediate-risk PTV was mostly lower. Volumes receiving 60 Gy (in equivalent dose in 20 Gy fractions) were approximately twice as large for IMRT compared with BT. For IMPT, this volume ratio was lower. Planning target volume doses of IMPT plans with 3-mm margins were comparable to those with BT. Gross tumor volume doses were mostly lower for both IMRT and IMPT. Conclusion For benchmarking high-tech EBT, high-tech BT techniques have to be used. For cervix cancer boost treatments, both IMRT and IMPT seem to be inferior to advanced BT.

Image-Guided Radiotherapy for Cervix Cancer: High-Tech External Beam Therapy Versus High-Tech Brachytherapy

MRI-guided prostate radiation therapy planning: Investigation of dosimetric accuracy of MRI-based dose planning

MRI is being increasingly used in oncology for staging, assessing tumour response and also for treatment planning in radiotherapy. Both conformal and intensity-modulated radiotherapy requires improved means of defining target volumes for treatment planning in order to achieve its intended benefits. MRI can add to the radiotherapy treatment planning (RTP) process by providing excellent and improved characterization of soft tissues compared with CT. Together with its multiplanar capability and increased imaging functionality, these advantages for target volume delineation outweigh its drawbacks of lacking electron density information and potential image distortion. Efficient MR distortion assessment and correction algorithms together with image co-registration and fusion programs can overcome these limitations and permit its use for RTP. MRI developments using new contrast media, such as ultrasmall superparamagnetic iron oxide particles for abnormal lymph node identification, techniques such as dynamic contrast enhanced MRI and diffusion MRI to better characterize tissue and tumour regions as well as ultrafast volumetric or cine MR sequences to define temporal patterns of target and organ at risk deformity and variations in spatial location have all increased the scope and utility of MRI for RTP. Information from these MR developments may permit treatment individualization, strategies of dose escalation and image-guided radiotherapy. These developments will be reviewed to assess their current and potential use for RTP and precision high dose radiotherapy.

New developments in MRI for target volume delineation in radiotherapy.

Effects of geometric distortion in 0.2T MRI on radiotherapy treatment planning of prostate cancer.

Internetbasierte Anwendungen eroffnen weitreichende Moglichkeiten der Kommunikation und des Datenaustausches. Wir stellen in diesem Zusammenhang ein in Entwicklung befindliches verteiltes Bilddatenbank- und Bildverarbeitungssystem fur medizinische Bilder vor. Die Benutzerschnittstelle und Kommunikation mit Servern wird in Java-Technologie realisiert. Das System verwaltet medizinische Bilder verschiedener Formate (DICOM [1], JPEG, GIF,...), und erlaubt dem Benutzer, Bildverarbeitungsoperationen auf die in der Datenbank oder lokal abgelegten Bilder anzuwenden. Hierbei werden einfache Bildmanipulationen wie Drehen, Spiegeln, Kontrast- und Helligkeitsveranderungen und Markierungsfunktionen bis zu Segmentationsverfahren wie Watershedding und der Visualisierung von dreidimensionalen Volumendaten [2] unterstutzt. Die Datenbank wird in der Lage sein, einfache Abfragen bezuglich Patienten, Organen, Krankheitssymptomen u.a. zu beantworten.

Ein verteiltes Bilddatenbank- und Bildverarbeitungssystem für medizinische Bilder

Vorgestellt wird ein interaktiver Ansatz zur Registrierung von beliebigen, multimodalen Volumendatensatzen, durch den eine hohe Genauigkeit, Schnelligkeit und intuitives, leichteres Handling der Daten im Vergleich mit automatischen Methoden ermoglicht wird.

Registrieren, Matching und Fusionieren von Volumendatensätzen

Purpose To evaluate the protective effect on corneal endothelial cells of a low-cost and an expensive combination of a dispersive viscoelastic material and an irrigating solution during phacoemulsification. Setting Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods This prospective randomized examiner- and patient-masked study comprised 90 eyes of 45 consecutive patients with age-related cataract in both eyes. For each patient, the first eye was randomly assigned to receive hydroxypropyl methylcellulose 2% (Ocucoat®) and Ringer’s solution (low-cost combination) or sodium chondroitin sulfate 4%–sodium hyaluronate 3% (Viscoat®) and an enriched balanced salt solution (BSS Plus®) (expensive combination) during phacoemulsification. The contralateral eye received the other treatment. Endothelial cell function was evaluated by measuring corneal thickness (CT) using partial coherence interferometry, morphology assessment, and endothelial cell counts. Results The acute postoperative increase in CT was +9.8 μm in the low-cost group and +10.9 μm in the expensive group; the difference between groups was not significant. After 1 month, the CT still differed significantly from baseline in the low-cost group. Three months after surgery, the CT had returned to baseline values in both groups. There was no significant between–group difference in endothelial cell counts or morphology. Conclusions During phacoemulsification in a nonselected patient population, there was no difference in acute postoperative corneal edema and endothelial cell morphology after 3 months between a Viscoat and BSS Plus combination and an Ocucoat and Ringer’s solution combination. Eyes receiving the expensive combination had marginally faster recovery of corneal swelling by 3 months. However, the cost of Viscoat and 500 mL BSS Plus is 5 times that of Ocucoat and Ringer’s solution.

Corneal endothelial cell protection with a dispersive viscoelastic material and an irrigating solution during phacoemulsification: low-cost versus expensive combination.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Thomas Lorang

Author Tools

Chat about Author

Papers

Effects of geometric distortion in 0.2T MRI on radiotherapy treatment planning of prostate cancer.

Ein verteiltes Bilddatenbank- und Bildverarbeitungssystem für medizinische Bilder

Registrieren, Matching und Fusionieren von Volumendatensätzen

Corneal endothelial cell protection with a dispersive viscoelastic material and an irrigating solution during phacoemulsification: low-cost versus expensive combination.