Hungarian Radiology

[Ways of imaging the expression of vascular endothelial growth factor and its receptor]

KOROM Csaba, KARLINGER Kinga

OCTOBER 20, 2009

Hungarian Radiology - 2009;83(03)

[The vascular endothelial growth factor (VEGF) and its receptors (VEGFR) signal-transduction pathway play a key role in the regulation of angiogenesis. It was originally isolated as a selective mitogen for endothelial cells and as a powerful vascular permeability increasing factor. The vascular imaging techniques make the quantification and localization of blood vessels possible. They have been used to assess blood flow, oxygenation, and vascular permeability. Also, they can be used to examine the molecular and cellular difference in the vascular wall. To evaluate tumour vascularity, a multimodality approach is expanding. VEGF as the primary mediator for vascular-permeability is indirectly measurable with DCE-MRI (dynamic contrastenhanced MRI). MRI investigation can determine the ratio of deoxyhemoglobin/oxyhemoglobin in order to localize the hypoxic regions in vivo (BOLD [blood oxygen-level dependent] sequence and OMRI [Overhauser MRI]). In molecular MRI (mMRI), contrast agent-mediated alteration of tissue relaxation times can allow for the detection and localization of molecular disease markers. To localize the expression of VEGFR with SPECT and PET, antibodies and VEGF isoforms can be marked with isotopes. VEGFR is an excellent candidate for targeted ultrasound imaging since it is almost exclusively expressed on activated endothelial cells. Optical imaging is a relatively cheap method suitable so far primarily for small animal studies.]

COMMENTS

0 comments

Further articles in this publication

Hungarian Radiology

[Portal embolisation prior to liver resection]

MÓZES Péter, MÉSZÁROS György, TÓTH Judit, SÁPY Péter

[INTRODUCTION - By partial embolisation of the vena portae the number of the patients suitable for radical liverresection can be enhanced, the safety of the operation can be increased, the subsequent results improved. The method is based on the experience that when blocking the circulation of the portal system in special segments of the liver, the other part of the organ tries to substitute the functional deficiency by hypertrophy. Vena portae embolisation is justified in cases when the liver substance remaining after the planned operation is critically small. PATIENTS AND METHODS - The authors carried out vena portae embolisation at Debrecen University Medical and Health Science Centre since October 2003 on six patients. Assessments were made studying the volume of the whole liver, the lobe affected by embolisation and that of the unaffected lobe, by CT-volumetry. The average age of the patients (four men and two women) was 63 years (51-67 years). The hepatic tumour was an extended metastasis localised to one lobe in five cases, and HCC in one of the patients. In each case we carried out closing the right lobe’s portal system. RESULTS - In five cases the left lobe showed increase following the portal embolisation of the right lobe intended to be removed. On the average four-six weeks passed between the two CT-examinations. The growth of the left lobe was an average of 42% (min. 11.8%, max. 75.6%). CONCLUSION - In selected patients the embolisation of the vena portae system of the tumorous liver-segments is a suitable method for enlargening the size of the liver substance remaining after an extensive resection.]

Hungarian Radiology

[“Indian summer” at Sárvár 14th Congress of the Society of Hungarian Radiographers - Sárvár, September 17-19th, 2009.]

PAVLIKOVICS Gábor, VANDULEK Csaba

Hungarian Radiology

[Omental infarction diagnosed with ultrasonography]

VÁRKONYI Ildikó, VÖRÖS Péter, SZÉKELY Eszter

[INTRODUCTION - Omental infarction is a rare entity, mimicking symptoms of acute appendicitis. Although omental infarction has typical morphology, both on sonography and CT, it is rarely diagnosed preoperatively. CASE REPORT - A 4-years-old girl presenting with right lower quadrant abdominal pain underwent abdominal sonography, which revealed normal appendix and a superficial hyperechoic solid mass at the site of the pain. The patient underwent laparotomy which confirmed the presumed diagnosis of partial omental necrosis. The necrotic tissue was resected, the appendix was normal. After uneventful postoperative course the child became symptom -free and was discharged. CONCLUSION - The sonomorphology of omental infarction is typical. The suspicion of this entity should be considered as a differential diagnosis of appendicitis, especially if normal appendix can be visualized.]

Hungarian Radiology

[Farewell to dr. József Soós 1926-2009]

VICZENA Pál

Hungarian Radiology

[Ultrasound diagnostics: method or art?]

HARKÁNYI Zoltán

All articles in the issue

Related contents

LAM KID

[New findings in the cortical bone biology and its role in bone fractures]

BALOGH Ádám, BHATTOA Harjit Pál

[The authors surveyed the already known factors responsible for the osteoporotic bone fragility. Then the results of using modern imaging techniques (micro-CT, high-resolution peripheral computed quantitative tomograph - HR-pQCT) and advanced computer analytic methods (finite element analysis, FEA) are presented. These data - beyond the already known fracture risk factors (age, risk of falling, bone mineral density - BMD, and fine structure damage of trabecular bone) are stressing the importance of the (micro)damage of cortical bone as a fracture risk factor, which has been still underrated. The cortical thickening and increased porosity - verified on various population samples - are increasing the risk of fractures in certain subgroups of subjects having identical BMD values, even among those, who are considered only osteopenic by the earlier classification based on BMD values. Backed with modern software batteries, the new imaging techniques are expected to enter clinical application in the near future. Pharmacologic agents with stronger cortical effect are already available and research is continuing to find new drugs to use in the management of osteoporotic patients of high fracture risk.]

Hungarian Radiology

[Radiologic imaging in the diagnosis and follow up of malignant lymphomas]

PETRI Klára, HORVÁTH Anikó, MOLNÁR Zsuzsa, VÁRADY Erika, SCHNEIDER Tamás, ROSTA András, GŐDÉNY Mária

[Certain viral infections, gene mutations and immune suppression are likely to play some role in the development of malignant lymphomas. The clinical stage at the time of diagnosis is a decisive factor of prognosis. The evaluation of the nodal and extranodal manifestation of the disease is performed by standardized imaging techniques. Most frequent extranodal manifestation involves the bone marrow, the lung and the gastrointestinal tract. Different imaging techniques are indispensable in monitoring the effectiveness of the treatment and in long term follow up.]

Clinical Oncology

[The role of PET in clinical oncology]

LENGYEL Zsolt

[Positron emission tomography (PET) has earned an important role in clinical imaging, where it is used almost exclusively as hybrid modality such as PET/CT and PET/MR. The driving force behind the development of the method and the increasing clinical penetration of PET in the past two decades was clearly its use in Oncology. The most used tracer in PET is the 18 F-labeled fl uoro-deoxy-glucose (FDG). With the help of this molecule malignant tumors and their metastases, in which anaerobic glycolysis is typically increased, can be identifi ed with high sensitivity in the total body volume. However, FDG is not a tumor specifi c tracer, thus both false positivity and false negativity may occure which reduces the diagnostic accuracy. Indications of FDG PET studies in Oncology continuously evolved, owing to scientifi c publications, large scale national programs and even health-economic considerations. This publication describes the well-established indications of FDG PET/CT(MR) tests in cancer diagnostics and furthermore discusses more recent new PET tracers already being applied as well as those expected to be used in the future.]

Hungarian Immunology

[The role of endothelium, cell migration, chemokines and angiogenesis in inflammatory rheumatic diseases]

BESENYEI Tímea, PÁKOZDI Angéla, VÉGVÁRI Anikó, SZABÓ Zoltán, SZEKANECZ Zoltán

[Endothelial cells, leukocyte-endothelial interactions and angiogenesis are highly involved in the pathogenesis of inflammation and thus in that of inflammatory rheumatic diseases. As this research area is very progressive, one needs to review novel molecular mechanisms and new therapeutic approaches in this respect. Authors review the most important functions of endothelial cells, the process of leukocyte extravasation, tissue infiltration and their cellular and molecular basis. Endothelial cells themselves produce a number of inflammatory mediators including interleukin-1 (IL-1), IL-6, IL-8, chemokines and others. Among cell adhesion molecules, β1 and β3 integrins, as well as E-, L- and P-selectins and their respective ligands have been implicated in leukocyte-endothelial adhesion. In recent years, numerous inflammatory mediators, cytokines, chemokines and proteases have been implicated in angiogenesis and angiostasis. Hypoxia, the vascular endothelial growth factor (VEGF)-angiopoietin system and mechanisms driven by β3 integrins are of major importance during angiogenesis. Significant amount of data have become available of the regulation of cell adhesion, migration and neovascularisation. Adhesion, chemokine and angiogenesis research has important clinical, practical aspects for antirheumatic and anti-cancer therapy. VEGF antagonists, anti-integrin antibodies, chemokine and chemokine receptor inhibitors, as well as thalidomide are currently in the first line of development.]

Clinical Oncology

[Angiogenesis – antiangiogenesis]

PAKU Sándor, SEBESTYÉN Anna, KOPPER László

[Tumor growth requires vascularization to be supplied by oxygen and nutritients. The vascular network could be different between tumors, even during the development of the same tumor (local and systemic spreading), from the occupation of already present vessels to the real angiogenesis (i.e, proliferation of endothelial cells). Moreover, the tumor cells can create channels, mimicking the normal vessels. This spectrum in morphology should be refl ected in the therapeutic response, in the effectiveness of antiangiogens, but the how is unknown. It is sure that acceptable clinical activity can be achieved only with combinations, both with traditional cytotoxic and targeting drugs. The clinical advantage can be hampered by increased toxicity, demanding supportive actions. One of the key decisions is to select the proper therapy considering the patient and the tumor characteristics (today increasingly at molecular level) and predict the response to the therapy. Such (bio)markers are still missing, although intensive research trying the best. Since the main target of antiangiogenic drugs (today and tomorrow) the VEGF/R family, a useful marker is expected from them. The inhibition of angiogenesis is a logical step against the solid tumors and these steps slowly but steadily can improve the patients life-time, as well as their quality of life.]