Automated procedure assessing the accuracy of HRCT-PET registration applied in functional virtual bronchoscopy.

Background: Bronchoscopy serves as direct visualisation of the airway. Virtual bronchoscopy provides similar visual information using a non-invasive imaging procedure(s). Early and accurate image-guided diagnosis requires the possible highest performance, which might be approximated by combining anatomical and functional imaging.

Q-Bot: automatic DICOM metadata monitoring for the next level of quality management in nuclear medicine.

Background: Regular and precise inspection of the realization of the local nuclear medicine standard operation procedures (SOPs) is very complex and time-consuming, especially when large amount of patient data is obtained from a wide scale of different scan procedures on a daily basis. DICOM metadata comprise a complete set of data related to the patient and the imaging procedure, and consequently all information necessary to evaluate the compliance with the actual SOP.

Methods: Q-Bot, an automatic DICOM metadata monitoring tool which is capable to verify SOP conformities, was tested for 11 months at two nuclear medicine departments.

OAR sparing 3D radiotherapy planning supported by fMRI brain mapping investigations.

The human brain as an organ has numerous functions; some of them can be visualized by functional imaging techniques (e.g., functional MRI [fMRI] or positron emission tomography).

Activity painting: PET images of freely defined activity distributions applying a novel phantom technique.

The aim of this work was to develop a novel phantom that supports the construction of highly reproducible phantoms with arbitrary activity distributions for PET imaging. It could offer a methodology for answering questions related to texture measurements in PET imaging. The basic idea is to move a point source on a 3-D trajectory in the field of view, while continuously acquiring data.

A Study on the Basic Criteria for Selecting Heterogeneity Parameters of F18-FDG PET Images.

Textural analysis might give new insights into the quantitative characterization of metabolically active tumors. More than thirty textural parameters have been investigated in former F18-FDG studies already. The purpose of the paper is to declare basic requirements as a selection strategy to identify the most appropriate heterogeneity parameters to measure textural features.

Population based ranking of frameless CT-MRI registration methods.

Background: Clinical practice often requires simultaneous information obtained by two different imaging modalities. Registration algorithms are commonly used for this purpose. Automated procedures are very helpful in cases when the same kind of registration has to be performed on images of a high number of subjects.

Excel2Genie: A Microsoft Excel application to improve the flexibility of the Genie-2000 Spectroscopic software.

Excel2Genie, a simple and user-friendly Microsoft Excel interface, has been developed to the Genie-2000 Spectroscopic Software of Canberra Industries. This Excel application can directly control Canberra Multichannel Analyzer (MCA), process the acquired data and visualize them. Combination of Genie-2000 with Excel2Genie results in remarkably increased flexibility and a possibility to carry out repetitive data acquisitions even with changing parameters and more sophisticated analysis.

Cold wall effect eliminating method to determine the contrast recovery coefficient for small animal PET scanners using the NEMA NU-4 image quality phantom.

The contrast recovery coefficients (CRC) were evaluated for five different small animal PET scanners: GE Explore Vista, Genisys4, MiniPET-2, nanoScan PC and Siemens Inveon. The NEMA NU-4 2008 performance test with the suggested image quality phantom (NU4IQ) does not allow the determination of the CRC values for the hot regions in the phantom. This drawback of NU4IQ phantom motivated us to develop a new method for this purpose.

[Prognostic value of FDG-PET in Hodgkin lymphoma for posttreatment evaluation. Long-term follow-up results].

Unlabelled: In the past few decades Hodgkin lymphoma (HL) has become a highly curable malignant disease, as a result of using modern polychemotherapy and irradiation. Differentiation of active tumor from fibrosis or necrosis within residual radiographic masses represents a problem of interpretation.

Aims: The aim of this retrospective study is to assess the value of FDG-PET for prediction of remission or relapse in HL.

Serial noninvasive in vivo positron emission tomographic tracking of percutaneously intramyocardially injected autologous porcine mesenchymal stem cells modified for transgene reporter gene expression.

Background: Porcine bone marrow-derived mesenchymal stem cells (MSCs) were stably transfected with a lentiviral vector for transgene expression of the trifusion protein renilla luciferase, red fluorescent protein and herpes simplex truncated thymidine kinase (LV-RL-RFP-tTK; positron emission tomography [PET] reporter gene) for in vivo noninvasive tracking of the intramyocardially delivered MSC fate.

Methods And Results: A closed-chest, reperfused myocardial infarction was created in farm pigs. Sixteen days after myocardial infarction, LV-RL-RFP-tTK-MSCs were injected intramyocardially using electromechanical mapping guidance in the infarct border zone (n=7).

Daunorubicin and doxorubicin inhibit the [(11)C]choline accumulation in cancer cells.

We studied how very short (10-40min) incubation with anthracycline derivatives modifies the accumulation of PET tumor-diagnostic radiotracers in cancer cells. The human ovarian A2780 and A2780AD, human B lymphoid JY, human epidermoid KB-3-1 and KB-V-1, and smooth muscle DDT1 MF-2 cells were pre-incubated with daunorubicin and doxorubicin, and the uptake of [(18)F]FDG and [(11)C]choline was measured. Anthracycline treatment decreased remarkably the [(11)C]choline accumulation in a concentration dependent manner, while it did not modify significantly the [(18)F]FDG uptake of the cells.

Pallidal deep brain stimulation and L-dopa effect on PET motor activation in advanced Parkinson's disease.

BACKGROUND AND PURPOSE The antiakinetic effect of internal Globus pallidus deep brain stimulation (Gpi-DBS) in Parkinson's disease is not clear and not either how this effect is modulated by L-dopa. METHODS Left Gpi-DBS and/or L-dopa effect was studied with auditory paced right-handed sequential movements on (15)O-butanol positron emission tomography (PET) in five patients. Rest and for conditions during movements (DBS off/L-dopa off; DBS on/L-dopa off; DBS off/L-dopa on; DBS on/L-dopa on) were compared with statistical parametric mapping.

Regional cerebral (18)FDG uptake during subarachnoid hemorrhage induced vasospasm.

Objectives: The aim was to elucidate whether aneurysmal subarachnoid hemorrhage (SAH)-induced vasospasm induces changes of regional glucose uptake in surgically treated, asymptomatic cases.

Methods: (18)FDG uptake (standardized uptake value, SUV) was analysed with PET in eight surgically treated aneurismal patients with a mean middle cerebral artery flow velocity >120 cm/seconds measured with transcranial Doppler ultrasound. Data were compared with a healthy control group using Statistical Parametric Mapping (SPM99b).

Na+/Ca2+ exchanger inhibitors modify the accumulation of tumor-diagnostic PET tracers in cancer cells.

Aim: To establish the effects of Na(+)/Ca(2+) exchanger (NCX) blockers on 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)FDG) and (11)C-choline accumulation in different cancer cells.

Methods: The tumor cells were incubated with NCX inhibitors, and the uptakes of (18)FDG and (11)C-choline were measured. Flow cytometric measurements of intracellular Ca(2+) and Na(+) concentrations were carried out.

Pattern of increased cerebral FDG uptake in Down syndrome patients.

Resting cerebral glucose metabolism was assessed by 18[F]-fluorodeoxyglucose in 11 Down syndrome patients. Standardized uptake values were determined on a pixel-by-pixel basis from the measured tissue-activity data. The results revealed a mean overall 18[F]-fluorodeoxyglucose uptake in the Down syndrome patients close to that observed in the control group, consisting of children and young adults.

Paclitaxel modifies the accumulation of tumor-diagnostic tracers in different ways in P-glycoprotein-positive and negative cancer cells.

Aim: To study how paclitaxel treatment modifies the accumulation of tumor-diagnostic radiotracers in P-glycoprotein (P-gp) positive and negative cancer cells.

Methods: The accumulations of different P-gp substrates, including rhodamine 123, daunorubicin and [(99m)Tc]hexakis-2-methoxybutyl isonitrile ((99m)Tc-MIBI), were measured in P-gp-positive (A2780AD) and P-gp-negative human ovarian carcinoma cells (A2780) and JY human lymphoid B cells. The uptakes of the tumor-diagnostic tracers (11)C-choline and 2-[(18)F]fluoro-2-deoxy-d-glucose ((18)FDG) were measured in the same cell lines.

Brain blood flow changes measured by positron emission tomography during an auditory cognitive task in healthy volunteers and in schizophrenic patients.

Objective: Cognitive deficit is an essential feature of schizophrenia. One of the generally used simple cognitive tasks to characterize specific cognitive dysfunctions is the auditory "oddball" paradigm. During this task, two different tones are presented with different repetition frequencies and the subject is asked to pay attention and to respond to the less frequent tone.

Role of the Na+/Ca2+ exchanger in calcium homeostasis and human sperm motility regulation.

A number of cell functions, such as flagellar beating, swimming velocity, acrosome reaction, etc., are triggered by a Ca2+ influx across the cell membrane. For appropriate physiological functions, the motile human sperm maintains the intracellular free calcium concentration ([Ca2+]i) at a submicromolar level.

[The role of positron emission tomography (PET) in the detection of local recurrence and metastases of colorectal cancer].

We presented here the results of PET imaging of 12 patients, previously operated on for colorectal cancer and followed at the 1st Department of Surgery, University of Debrecen. The tests were carried out using 0.15 mCi/kg FDG injections.

Biphasic accumulation kinetics of [99mTc]-hexakis-2-methoxyisobutyl isonitrile in tumour cells and its modulation by lipophilic P-glycoprotein ligands.

Aim: To study the accumulation and washout kinetics of [99mTc]-hexakis-2-methoxyisobutyl isonitrile (99mTc-MIBI) in MDR positive and MDR negative tumour cells and how this is modified by lipophilic P-glycoprotein ligands.

Methods: The tumour cells were incubated in the presence and absence of the ligands and the uptakes of 99mTc-MIBI, rhodamine 123 and 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) were measured.

Results: The accumulation of 99mTc-MIBI in the tumour cells followed biphasic kinetics.

[Volumetric changes following 125I interstitial brachytherapy of gliomas].

Background: Image fusion permits quantitative analysis of the consequences of 125 Iodine interstitial irradiation of brain tumors. The volume of tumor necrosis, reactive zone and edema can be compared to the dosimetric data.

Patients And Method: Nineteen patients with low grade glioma were analyzed on the average 14.

Does increased 18FDG uptake reflect malignant transformation of a low-grade glioma? A diagnostic dilemma.

Benign gliomas of the brain show decreased uptake of 18F fluorodeoxyglucose (FDG) on positron emission tomography (PET). Malignant transformation is usually manifested by an increase of 18FDG uptake. A 45-year-old female has been followed up since 1987 by means of 18FDG-PET for a right hemispheric World Health Organization Grade II oligoastrocytoma.

Effects of miltefosine on membrane permeability and accumulation of [99mTc]-hexakis-2-methoxyisobutyl isonitrile, 2-[18F]fluoro-2-deoxy-D-glucose, daunorubucin and rhodamine123 in multidrug-resistant and sensitive cells.

Miltefosine is a phospholipid analog that exhibits antineoplastic activity against breast cancer metastases, but its mechanism of action remains uncertain. The aim of this study was to investigate the transport mechanism for the removal of miltefosine and [99mTc]-hexakis-2-methoxyisobutyl isonitrile (99mTc-MIBI) from multidrug-resistant cells. The P-glycoprotein pump function, cell viability, and 99mTc-MIBI and 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) uptakes were measured in NIH 3T3 (3T3) and NIH 3T3MDR1 G185 (3T3MDR1) mouse fibroblasts and human lymphoid B JY cells.