Wyniki wyszukiwania - BazTech

1

Study and adjustment of dermoscopic image processing algorithms for lesion border detection

Borys D., Szeremet M., Psiuk-Maksymowicz K., Ostrowski Z., Frąckiewicz M.

Studia Informatica

|

2016

|

Vol. 37, nr 3B

33-46

EN

The goal of our work was an initial preprocessing of dermoscopic images towards accurate lesion border detection. Four algorithms were proposed and analyzed: MS – algorithm using mean shift clustering, HE – algorithm using histogram equalization, TTH – algorithm using the top-hat transform, PCA – algorithm using principal component analysis. Those algorithms were tested on PH2 images database that contains 200 dermoscopic images, each with a mask of the lesion. Those algorithms were optimized using lesion mask from database and Jaccard index as a measure of similarity of both sets. Simple statistical analysis of indexes was used to compare proposed algorithms in term of their accuracy.

PL

W artykule poruszono problem wstępnego przetwarzania obrazów dermatoskopowych w celu znalezienia konturu znamienia. Zaproponowano i porównano cztery algorytmy: MS – wykorzystujący klasteryzację ‘mean shift’, HE – wykorzystujący wyrównywanie histogramu, TTH – wykorzystujący transformację ‘top-hat’, PCA – wykorzystujący metodę analizy głównych składowych. Algorytmy przetestowano z wykorzystaniem obrazów z bazy PH2, zawierającej 200 obrazów wraz z obrysem ręcznym, a ich parametry dobrano optymalizując indeks Jaccarda. Proste statystyki wyników pozwoliły na porównanie proponowanych algorytmów.

2

Evaluation of SPECT-CT image fusion quality control

Borys D., Panek R., Gorczewski K., d'Amico A., Steinhof K., Psiuk-Maksymowicz K.

Biocybernetics and Biomedical Engineering

|

2006

|

Vol. 26, no. 4

79-90

EN

Co-registration of different types of studies into one multimodal image is a very powerful tool which provides more (complementary) information than both studies analyzed separately. The aim of this paper is to demonstrate the importance and to provide a measure of quality control in SPECT-CT studies. The resuIt of image fusion has a diagnostic value only when precision of co-registration is known and falls below an acceptable level. It is very important to evaluate an error of each fusion result. This parameter, while unknown, may lead to incorrect diagnostic decisions, especially when none of the anatomical structures are visualized, like in case of imaging iodine-131 patients.

3

CT/SPECT image fusion in patients treated with iodine-131

Psiuk-Maksymowicz K., Borys D., Gorczewski K., Steinhof K., d'Amico A.

Journal of Medical Informatics & Technologies

|

2004

|

Vol. 8

II7--12

EN

Computer tomography gives visualization of anatomical structures and abnormalities, but it lacks of functional information. On the other hand, single photon emission tomography provides the missing information about the tumour function, but it has relative low resolution and the localization of the visible focus may be difficult, especially when iodine ¹³¹I is used. Thus, several methods of image fusion are applied. We present an algorithm of image fusion based on affine transformation. On the base of a phantom study, we showed that the created program can be a useful tool to fuse CT and SPECT images and then applied to patients' datasets. External marker method was used to align patient functional and anatomical data. Image alignment quality depends on appropriate marker placement and acquisition protocol. The program estimates maximal misalignment in a volume between the markers. Created acquisition protocol minimizes misalignment of patient placement on both CT and gamma camera, however misalignment derived from respiratory movements cannot be avoided. The proposed technique is simple, low-cost and can be easily adopted in any hospital or diagnostic centre equipped with gamma camera and CT. Fusion of morphology and function can improve diagnostic accuracy in many clinical circumstances.