introduction: in brachytherapy, radioactive sources are placed close to the tumor, therefore, small changes in their positions can cause large changes in the dose distribution. this emphasizes the need for computerized treatment planning. the usual method for treatment planning of cervix brachytherapy uses conventional radiographs in the manchester system. nowadays, because of their advantages ...

Off-pump beating heart surgery requires a guidance system that would show both pertinent cardiac anatomy and dynamic motion both periand intra-operatively. Optimally, the guidance system should show high quality images and models in a cost-effective way and can be easily integrated into standard clinical workflow. However, such a goal is difficult to accomplish by a single image modality. In th...

BACKGROUND: Attenuation correction is generally used to PET images to achieve count rate values independent from tissue densities. The goal of this study was to provide a qualitative comparison of attenuation corrected PET images produced by a PET-CT device (CT, 120 kV, 40 mAs, FOV 600 mm) with and without segmentation of transmission data (ACseg+ and ACseg-respectively). Methods: The reconstru...

Positron emission tomography (PET) is a non-invasive imaging modality, which is clinically widely used both for diagnosis and accessing therapy response in oncology, cardiology and neurology.Fusing PET and CT images in a single dataset would be useful for physicians who could read the functional and the anatomical aspects of a disease in a single shot.The use of fusion software has been replace...

Medical imaging is both expensive because of capital costs and easy to perform because of its noninvasive nature. It is clearly very important to extract the maximum possible information from any image obtained. However, image processing modes based on scan sections or radiographic views do not completely provide diagnostic information in advance, when it would be easier to control a disease, m...

X-ray computed tomography (CT) is a medical imaging modality that allows reconstruction of the internal stucture of the human body from a large number of x-ray attenuation measurements. In recent years, the development of spectral CT, in which the energy dependence of the x-ray attenuation coe cient is utilized, has attracted considerable interest. This thesis is concerned with a spectral CT sy...

Conformal radiotherapy is a therapeutic method requiring medical imaging, generally CT images to obtain Hounsfield number and electronic density data indications. The use of MRI simultaneously with CT imposes to deform CT images and superimpose them on MR images. The aim of this paper is to propose a nonridgid matching method between the two modalities (CT and MRI). The transformation model is ...

OBJECTIVES The aim was to assess the performance of low-dose non-contrast CT of the urinary tract (LD-CT) acquired at radiation exposures close to that of abdominal radiography using adaptive statistical iterative reconstruction (ASiR). METHODS Thirty-three patients with clinically suspected renal colic were prospectively included. Conventional dose (CD-CT) and LD-CT data sets were contempora...

This article discusses attenuation correction strategies in positron emission tomography/computed tomography (PET/CT) and 4-dimensional PET/CT imaging. Average CT scan derived from averaging the high temporal resolution CT images is effective in improving the registration of the CT and the PET images and quantification of the PET data. It underscores list-mode data acquisition in 4-dimensional ...

A 70-year-old man with past history of hemicolectomy due to colon cancer underwent a follow-up abdominal/pelvic CT scan. CT revealed a right adrenal metastasis and then he underwent FDG-PET/CT study to search for other possible tumor recurrence. In PET images, other than right adrenal gland, there was an unexpected intense FDG uptake at right inguinal region and at first, it was considered to b...