Alexandra Nikita

Nodular hepatic and splenic sarcoidosis in a patient with normal chest radiograph.

Almost all the patients with sarcoidosis have an abnormal chest radiograph, while nodular lesions of both the liver and the spleen is an unusual manifestation of abdominal sarcoidosis. We report a case of a patient with numerous hypodense nodular hepato-splenic lesions on abdominal CT and a normal chest X-ray. Biopsy of an hepatic lesion revealed sarcoidosis.

DIAGNOSIS: A Telematics-Enabled System for Medical Image Archiving, Management, and Diagnosis Assistance

In this paper, a modular system for medical image archiving, management, diagnosis support, and telematic cooperation is presented. The system provides digital imaging and communications in medicine (DICOM)-compatible tools for digital image processing and database management of medical images. The software features algorithms for preprocessing, manual or semi-automatic segmentation, automatic calculation of geometrical/size characteristics, and 3-D visualization of organs or selected regions of interest. Additionally, the system incorporates a database where patient data and information can be stored and retrieved. Access to the database is only permitted to authorized users. The user-friendly interface makes the software handy and accessible to clinicians, whereas the telematic components allow collaboration with remote experts. The pilot system incorporates a computer-aided diagnosis module aiming at providing support in the diagnosis of focal liver lesions from computed tomography images.

DIAGNOSIS: A Telematics Enabled System for Medical Image Archiving, Management and Diagnosis Assistance

In this paper, a modular system for medical image archiving, management, diagnosis support, and telematic cooper- ation is presented. The system provides digital imaging and com- munications in medicine (DICOM)-compatible tools for digital image processing and database management of medical images. The software features algorithms for preprocessing, manual or semi-automatic segmentation, automatic calculation of geomet- rical/size characteristics, and 3-D visualization of organs or se- lected regions of interest. Additionally, the system incorporates a database where patient data and information can be stored and retrieved. Access to the database is only permitted to authorized users. The user-friendly interface makes the software handy and accessible to clinicians, whereas the telematic components allow collaboration with remote experts. The pilot system incorporates a computer-aided diagnosis module aiming at providing support in the diagnosis of focal liver lesions from computed tomography images.

A fractal analysis of CT liver images for the discrimination of hepatic lesions: a comparative study

A quantitative study for the discrimination of different hepatic lesions is presented in this paper. The study is based on the fractal analysis of CT liver images in order to estimate their fractal dimension and to differentiate normal liver parenchyma from hepatocellular carcinoma. Four fractal dimension estimators have been implemented throughout this work; three well-established methods and a novel implementation of a method. Analytically, these methods correspond to the power spectrum method, the box counting method, the morphological fractal estimator and the novel modification of the kth-nearest neighbour method. The Fuzzy C-Means algorithm is finally applied revealing that the k-th nearest neighbour method outperforms the other methods; thus discriminating up to 93% of the normal parenchyma and up to 82% of the hepatocellular carcinoma, correctly.

Long-Term Outcome of a Hepatocellular Carcinoma 7½ Years After Surgery and Repeated Radiofrequency Ablation: Case Report and Review of the Literature

An interesting case is presented of a 78-year-old patient with cirrhosis who was managed with combined treatment (surgery and radiofrequency (RF) ablation) for hepatocellular carcinoma (HCC) and has survived for 7½ years. Elevation of the α-FP (alpha-fetoprotein) levels was noted 2 years after surgery. CT demonstrated two lesions: one central at the remaining right liver lobe, and the other at the excision site. Biopsy of the lesions confirmed the diagnosis of HCC for both of them. RF ablation of these two lesions was performed in one session with technical success. Four and a half years after the first RF ablation a new recurrence was demonstrated at the CT follow-up control. RF ablation was again applied successfully. The imaging findings and the therapeutic percutaneous management of this patient along with the natural course of HCC and its recurrence are discussed, and the literature concerning risk factors is reviewed.

Computer Aided Diagnosis of CT Focal Liver Lesions based on Texture Features, Feature Selection and Ensembles of Classifiers

A computer aided diagnosis system aiming to classify liver tissue from computed tomography images is presented. For each region of interest five distinct sets of texture features were extracted. Two different ensembles of classifiers were constructed and compared. The first one consists of five Neural Networks (NNs), each using as input either one of the computed texture feature sets or its reduced version after feature selection. The second ensemble of classifiers was generated by combining five different type of primary classifiers, two NNs, and three k-nearest neighbor classifiers. The primary classifiers of the second ensemble used identical input vectors, which resulted from the combination of the five texture feature sets, either directly or after proper feature selection. The decision of each ensemble of classifiers was extracted by applying voting schemes.