Sandro Squarcia

A CAD system for nodule detection in low‐dose lung CTs based on region growing and a new active contour model

A computer-aided detection (CAD) system for the selection of lung nodules in computer tomography (CT) images is presented. The system is based on region growing (RG) algorithms and a new active contour model (ACM), implementing a local convex hull, able to draw the correct contour of the lung parenchyma and to include the pleural nodules. The CAD consists of three steps: (1) the lung parenchymal volume is segmented by means of a RG algorithm; the pleural nodules are included through the new ACM technique; (2) a RG algorithm is iteratively applied to the previously segmented volume in order to detect the candidate nodules; (3) a double-threshold cut and a neural network are applied to reduce the false positives (FPs). After having set the parameters on a clinical CT, the system works on whole scans, without the need for any manual selection. The CT database was recorded at the Pisa center of the ITALUNG-CT trial, the first Italian randomized controlled trial for the screening of the lung cancer. The detection rate of the system is 88.5% with 6.6 FPs/CT on 15 CT scans (about 4700 sectional images) with 26 nodules: 15 internal and 11 pleural. A reduction to 2.47 FPs/CT is achieved at 80% efficiency.

Laparoscopic splenectomy for hematologic diseases: a preliminary analysis performed on the Italian Registry of Laparoscopic Surgery of the Spleen (IRLSS).

BackgroundThe Italian Registry of Laparoscopic Surgery of the Spleen (IRLSS) was developed to provide at the national level an informative tool useful for performing multicenter studies in the field of spleen laparoscopic surgery. In this first study analyzing the IRLSS data, a cohort of patients with hematologic diseases was retrospectively investigated for potential predictive parameters that could affect the outcome of laparoscopic splenectomy.MethodsA total of 309 patients who underwent laparoscopic splenectomy for hematologic diseases in 17 Italian centers (between February 1, 1993, and September 30, 2004) were entered in the IRLSS. Their records were analyzed retrospectively by the Student’s t-test, chi-square, and logistic regression.ResultsThe mean operative time was 141 min (range, 30–420 min). Conversion was necessary in 21 cases (7%), and approximately 1 accessory spleen in 25 patients (9%) was found. The mean spleen weight was 1191 g (range, 85–4,500 g). Perioperative death occurred in two cases (0.6%). No complications were experienced by 253 patients (81.9%), who had a mean hospital stay of 5.4 days (range, 2–30 days). Overall morbidity occurred in 56 patients (18.1%), mainly associated with transient fever (n = 22), pleural effusion (n = 13), and actual or suspected hemorrhage (n = 12), requiring a reintervention for 7 patients. Multivariate analysis found that body mass index (p = 0.024) and clinical indication (p = 0.004) were independent predictors for surgical conversion. The clinical indication was almost significant as an independent predictor for the occurrence of postoperative complication (p = 0.05).ConclusionsThis first study analyzing the IRLSS data shows that laparoscopic splenectomy may represent the gold standard treatment for hematologic diseases with normal-size spleen. The low morbidity and mortality rate suggests that laparoscopic splenectomy can be successfully proposed also for splenomegaly in hematologic malignancies.

A superconducting magnet for a beam delivery system for carbon ion cancer therapy

The therapy of cancer (hadrontherapy) with accelerated particle beams is an out coming method that allows an accurate and effective treatment of several kinds of tumors minimizing the irradiation of the surrounding tissues and avoiding intercepting vital organs. The deep tumors are usually treated with proton or ion beams by using a rotating gantry that allows the 360/spl deg/ irradiation around the patient. For carbon ion hadrontherapy being the energy in the order of 400 MeV, huge gantries structure are required if resistive magnets are used. The size of a ion gantry can be of the order of 10 m in diameter and 100 tons in weight. An alternative solution has been studied, involving the use of a cryogenic free superconducting magnet. The magnet consists of ten 90/spl deg/ bent superconducting dipoles wound with an aluminum stabilized Cu/NbTi conductor and mechanically supported by an aluminum alloy structure. An optimization of the magnetic design is running by using genetic algorithms with the goal to obtain a field homogeneity within 0.2% in a region of 60/spl times/200 mm/sup 2/ along the beam path. Furthermore, an accurate study of the winding technique is in progress. The magnet will be kept at 4.5 K by a cooling system based on two cryocoolers operating alternately in steady state or together during the cool down and the electrical transients. The current is supplied via a couple of HTCS current leads always connected. In the paper, a description of the design is given.

Automatic temporal lobe atrophy assessment in prodromal AD: Data from the DESCRIPA study

In the framework of the clinical validation of research tools, this investigation presents a validation study of an automatic medial temporal lobe atrophy measure that is applied to a naturalistic population sampled from memory clinic patients across Europe.

Automatic localization of the hippocampal region in MR images to asses early diagnosis of Alzheimer’s disease in MCI patients

Atrophy and other brain changes, which are typical of aging, generate wide inter-individual variability of morphology in the medial temporal lobe (MTL), including the hippocampal formation. Starting from a sample population of 133 MR images we developed a procedure that extracts from each MR two sub images, containing the hippocampal formations plus a portion of the adjacent tissues and cavities. Then, a small number of templates is selected among the previously obtained sub images, able to describe the morphological variability present in the whole population. Finally an automatic procedure is prepared which, on the basis of the given set of templates, is able to find both hippocampal formations in any new MR image. MR images ranging from normalcy to extreme atrophy can be successfully processed. The proposed approach, besides being a preliminary step towards the unsupervised segmentation of the hippocampus, extracts from the MR image information useful for diagnostic purposes and, in particular, could give the possibility of performing morphometric studies on the medial temporal lobe in an automated way. The automated analysis of MTL atrophy in the segmented volume is readily applied to the early assessment of Alzheimer Disease (AD), leading to discriminating converters from Mild Cognitive Impairment (MCI) to AD with an average three years follow-up. This procedure can quickly and reliably provide additional information in early diagnosis of AD.

Network oriented radiological and medical archive

Abstract In this paper the basic ideas of NORMA (Network Oriented Radiological and Medical Archive) are discussed. NORMA is an original project built by a team of physicists in collaboration with radiologists in order to select the best Treatment Planning in radiotherapy. It allows physicians and health physicists, working in different places, to discuss on interesting clinical cases visualizing the same diagnostic images, at the same time, and highlighting zones of interest (tumors and organs at risk). NORMA has a client/server architecture in order to be platform independent. Applying World Wide Web technologies, it can be easily used by people with no specific computer knowledge providing a verbose help to guide the user through the right steps of execution. The client side is an applet while the server side is a Java application. In order to optimize execution the project also includes a proprietary protocol, lying over TCP/IP suite, that organizes data exchanges and control messages. Diagnostic images are retrieved from a relational database or from a standard DICOM (Digital Images and COmmunications in Medicine) PACS through the DICOM-WWW gateway allowing connection of the usual Web browsers, used by the NORMA system, to DICOM applications via the HTTP protocol. Browser requests are sent to the gateway from the Web server through CGI (Common Gateway Interface). DICOM software translates the requests in DICOM messages and organizes the communication with the remote DICOM Application.

The winding method and model of a superconducting bending dipole for hadrontherapy

The cancer therapy (hadrontherapy) with accelerated particle beams is an innovative method that allows an accurate and effective treatment of several kinds of tumors minimizing the irradiation of the surrounding tissues and avoiding intercepting vital organs. The deep tumors are usually treated with proton or ion beams by using a rotating gantry that allows the 360/spl deg/ irradiation of the patient. For the carbon ion hadrontherapy, being the energy in the order of 400 MeV, huge gantry structures are required if resistive magnets are used. An alternative solution was studied, involving the use of a cryogenic free superconducting magnet. The magnet consists of ten 90/spl deg/ bent superconducting dipoles wound with an aluminum stabilized Cu/NbTi conductor and mechanically supported by an aluminum alloy structure. In order to validate the feasibility of such a magnet, an accurate study of the winding technique was carried out, together with a winding test of a coil prototype.

Automatic Morphological Analysis of Medial Temporal Lobe

Research in Alzheimers disease (AD) has seen a tremendous growth of candidate biomarkers in the last decade. The role of such established or putative biomarkers is to allow an accurate diagnosis of AD, to infer about its prognosis, to monitor disease progression and evaluate changes induced by disease-modifying drugs. An ideal biomarker should detect a specific pathophysiological feature of AD, not present in the healthy condition, in other primary dementias, or in confounding conditions. Besides being reliable, a biomarker should be detectable by means of procedures which must be relatively non-invasive, simple to perform, widely available and not too expensive. At present, no candidate meets these requirements representing the high standards aimed at by researchers. Among others, various morphological brain measures performed by means of magnetic resonance imaging (MRI), ranging from the total brain volume to some restricted regions such as the hippocampal volume, have been proposed. Nowadays the efforts are directed toward finding an automated, unsupervised method of evaluating atrophy in some specific brain region, such as the medial temporal lobe (MTL). In this work we provide an extensive review of the state of the art on the automatic and semi-automatic image processing techniques for the early assessment of patients at risk of developing AD. Our main focus is the relevance of the morphological analysis of MTL, and in particular of the hippocampal formation, in making the diagnosis of AD and in distinguishing it from other dementias.

Medical Images Remote Consultation

Teleconsultation of digital images among different medical centers is now a reality. The problem to be solved is how to interconnect all the clinical diagnostic devices in a hospital in order to allow physicians and health physicists, working in different places, to discuss on interesting clinical cases visualizing the same diagnostic images at the same time. Applying World Wide Web technologies, the proposed system can be easily used by people with no specific computer knowledge providing a verbose help to guide the user through the right steps of execution. Diagnostic images are retrieved from a relational database or from a standard DICOM-PACS through the DICOM-WWW gateway allowing connection of the usual Web browsers to DICOM applications via the HTTP protocol. The system, which is proposed for radiotherapy implementation, where radiographies play a fundamental role, can be easily converted to different field of medical applications where a remote access to secure data are compulsory.

AN ONLINE CLINICAL FOLDER APPLIED TO CHOROIDAL MELANOMA TREATMENT

An on-line clinical folder has been optimised in order to manage all the available data coming from eight years of choroidal melanoma treatment with proton beams. The system allows the ophthalmologist, in a very easy way, to record and update, in different display sessions, the required data coming from the usual eye specialised visit, the tumour determination and identification, all the radiotherapy treatment information and the clinical data derived from the post-treatment follow-up visits. The goal is a better patient cure coming from statistical data treatment. This field is of great interest in oncology because only with analytical correlation study among the irradiated dose to the tumour and the relevant parameters of the tumour itself, is possible to optimise the used treatment planning.