Virtual Liver Resection and Volumetric Analysis of the Future Liver Remnant using Open Source Image Processing Software

Ó The Author(s) 2010. This article is published with open access at Springerlink.com Background After extended liver resection, a remnant liver that is too small can lead to postresection liver failure. To reduce this risk, preoperative evaluation of the future liver remnant volume (FLRV) is critical. The open-source OsiriX Ò PAC software system can be downloaded for free and used by nonradiologists to calculate liver volume using a stand-alone Apple computer. The purpose of this study was to assess the accuracy of OsiriX Ò CT volumetry for predicting liver resection volume and FLVR in patients undergoing partial hepatectomy. Methods Preoperative contrast-enhanced liver CT scans of patients who underwent partial hepatectomy were Joost R. van der Vorst and Ronald M. van Dam contributed equally to the study and the manuscript. These authors share first authorship. J. R. van der Vorst R. M. van Dam (&

Prospective Volumetric Assessment of the Liver on a Personal Computer by Nonradiologists Prior to Partial Hepatectomy

Ó The Author(s) 2010. This article is published with open access at Springerlink.com Background A small remnant liver volume is an important risk factor for posthepatectomy liver failure. ImageJ and OsiriX Ò are both free, open-source image processing software packages. The aim of the present study was to compare ImageJ and OsiriX Ò in performing prospective computed tomography (CT) volumetric analysis of the liver on a personal computer (PC) in patients undergoing major liver resection. Methods Patients scheduled for a right hemihepatectomy were eligible for inclusion. Two surgeons and one surgical trainee measured volumes of total liver, tumor, and future resection specimen prospectively with ImageJ and OsiriX Ò. A radiologist also measured these volumes with CT scanner-linked Aquarius iNtuition Ò software. Resection volumes were compared with the actual weights of the live

Liver Volumetry Plug and Play: Do It Yourself with ImageJ

AB - BACKGROUND: A small remnant liver volume is an important risk factor for posthepatectomy liver failure and can be predicted accurately by computed tomography (CT) volumetry using radiologic image analysis software. Unfortunately, this software is expensive and usually requires support by a radiologist. ImageJ is a freely downloadable image analysis software package developed by the National Institute of Health (NIH) and brings liver volumetry to the surgeon's desktop. We aimed to assess the accuracy of ImageJ for hepatic CT volumetry. METHODS: ImageJ was downloaded from http://www.rsb.info.nih.gov/ij/ . Preoperative CT scans of 15 patients who underwent liver resection for colorectal cancer liver metastases were retrospectively analyzed. Scans were opened in ImageJ; and the liver, all metastases, and the intended parenchymal transection line were manually outlined on each slice. The area of each selected region, metastasis, resection specimen, and remnant liver was multiplied by the slice thickness to calculate volume. Volumes of virtual liver resection specimens measured with ImageJ were compared with specimen weights and calculated volumes obtained during pathology examination after resection. RESULTS: There was an excellent correlation between the volumes calculated with ImageJ and the actual measured weights of the resection specimens (r(2) = 0.98, p < 0.0001). The weight/volume ratio amounted to 0.88 +/- 0.04 (standard error) and was in agreement with our earlier findings using CT-linked radiologic software. CONCLUSION: ImageJ can be used for accurate hepatic CT volumetry on a personal computer. This application brings CT volumetry to the surgeon's desktop at no expense and is particularly useful in cases of tertiary referred patients, who already have a proper CT scan on CD-ROM from the referring institution. Most likely the discrepancy between volume and weight results from exsanguination of the liver after resectio

LIQUID-CHROMATOGRAPHIC PROFILING OF AROMATIC METABOLITES IN NEURAL CREST TUMORS

The merits of liquid chromatography with electrochemical detection have been examined for their utility in the clinical analysis of important tyrosine metabolites. Primary emphasis was placed on the catecholamines--norepinephrine, epinephrine, dopamine--and their respective O-methylated metabolites--normetanephrine, metanephrine, and 3-methoxytyramine. The latter group of compounds is formed from the catecholamines through the action of the enzyme catechol-O-methyltransferase and S-adenosylmethionine. Mutually optimized conditions for both the separation of these amines on reverse phase media and their detection amperometrically are presented. The hybrid combination of liquid chromatography and electrochemical detection offered the advantages of highly efficient separations for improved selectivity, subpicomole sensitivity for the biogenic amines, and the convenience of direct detection. Reverse phase separations for the catecholamines required long chain sulfates or sulfonates; retention under these ion pairing conditions operated under a dynamic ion exchange mechanism. An analytical method for the determination of urinary metanephrines is described. The procedure employs small ion-exchange columns for the selective isolation of the amines before instrumental analysis. The combination of this method with a similar one for the urinary catecholamine precursors proved suitable for the metabolic profiling of several patients afflicted with pheochromocytoma and neuroblastoma. These nervous system tumors could be easily differentiated on the basis of the excretion profiles. For neuroblastoma, the differences in norepinephrines and epinephrine excretion between healthy and diseased patients were negligible. Dopamine, however, was grossly elevated in neuroblastoma. The benefits of multicomponent analysis in these specimens proved fruitful. Postoperative metabolic profiles were also run periodically to ascertain patient progress; the amines acted as appropriate markers in predicting the patient\u27s eventual fate. The applicability of LCEC to enzyme assays was also investigated in a study of COMT activity in various physiological matrices. The ability to simultaneously quantitate the multiple isomers produced in the reaction enabled the examination of different tissues for both absolute activities and product preferences

The metropolitan machine

There are many complex factors that determine the form of the metropolis, These factors act and react constantly and simultaneously. When writing about the metropolis, it is customary to mention at least the economic, social, and political factors. This paper attempts to reveal how powerful a form determinant the economic factor is in the metropolis. An analogy of the metropolis as a machine is used to explore the major parts of the metropolis and their functions. Three contemporary urban design theories are used to illustrate each of the parts and their functions each of these design theories is accompanied by a fundamental or parallel economic theory. It is hoped that this paper will expose one of the most powerful factors of form determination in the metropolis to the scrutiny and understanding of the urban designer so that he can design in concert with that factor instead of in opposition to it

A practical public key cryptosystem provably secure against adaptive chosen ciphertext attack

A new public key cryptosystem is proposed and analyzed. The scheme is quite practical, and is provably secure against adaptive chosen ciphertext attack under standard intractability assumptions. There appears to be no previous cryptosystem in the literature that enjoys both of these properties simultaneously

Design and Analysis of Practical Public-Key Encryption Schemes Secure against Adaptive Chosen Ciphertext Attack

A new public key encryption scheme, along with several variants, is proposed and analyzed. The scheme and its variants are quite practical, and are proved secure against adaptive chosen ciphertext attack under standard intractability assumptions. These appear to be the first public-key encryption schemes in the literature that are simultaneously practical and provably secure

Design and analysis of practical public-key encryption schemes secure against adaptive chosen ciphertext attack

A new public key encryption scheme, along with several variants, is proposed and analyzed. The scheme and its variants are quite practical, and are proved secure against adaptive chosen ciphertext attack under standard intractability assumptions. These appear to be the first publickey encryption schemes in the literature that are simultaneously practical and provably secure. This paper is a significantly revised and extended version of the extended abstract “A practical public key cryptosystem provably secure against adaptive chosen ciphertext attack ” [R. Cramer and V. Shoup, in “Using hash functions as a hedge against chosen ciphertext attack ” [V. Shoup, in Advances in Cryptology – Eurocrypt 2000]. Content