Abstract:
OBJECTIVES:Thermal dose in tumor tissue is a key factor for regional hyperthermia (HT) combined with chemotherapy and for drug delivery using thermosensitive liposomes (TSL). It influences therapy outcome, affects the accumulation of liposomes, and triggers the content release from TSL in the target tissue. For the development and clinical application of TSL, noninvasive visualization is of critical importance. For this purpose, TSL loaded with MRI contrast agent (CA) have been developed. With increase in temperature, the CA is released from TSL at the phase transition temperature Tm resulting in a relaxation time change, which allows MRI monitoring. The purpose of this study was to examine the feasibility of an in vivo application and MR characterization of Gd-DTPA-BMA-loaded phosphatidylglyceroglycerol-TSL (Gd-TSL) at mild HT conditions in tumor tissue using a clinically relevant setting. MATERIAL AND METHODS:Gd-TSL were characterized in vitro with varying thermal doses between 37 degrees C and 45 degrees C and distinct solvents by MR at 0.5 T and 1.5 T. In vivo studies were performed in C57BL/6 mice bearing BFS-1 fibrosarcomas at 1.5 T. One tumor-bearing leg was immersed in a temperature-controlled water bath (T). Gd-TSL (Tm = 43.5 +/- 0.2 degrees C) were injected either intratumorally or intravenously at T = 37.3 +/- 0.1 degrees C or T = 42.5 +/- 0.3 degrees C. As a control, nonliposomal Gd-DTPA-BMA was injected intravenously at T = 43.1 +/- 0.3 degrees C. A second tumor on the contralateral limb, which remained unheated, served as a control. CA release was monitored by T1-weighted spin-echo. RESULTS:The in vitro characterization demonstrated at heated and unheated samples a strong increase in T1-relaxivity of Gd-TSL solutions from 0.4 mM-1 s-1 (37.5 degrees C) to 4.2 mM-1 s-1 (43.3 degrees C) at 0.5 T. Thermal dose and solvent affected the rate of relaxation time change significantly. A fast and complete release was observed in samples with serum, whereas Gd-TSL in glucose was only partially released within 1 hour. A dedicated experimental setup was developed for standardized in vivo investigation. Tumor signal intensity changes were detectable in all animals. After intratumoral injection of Gd-TSL, the signal increased heterogeneously (max., +52% +/- 25%) within 3 minutes after temperature increase and decreased strongly thereafter, whereas after i.v. injection, the signal increased homogeneously (+19% +/- 3%) within 2 minutes persisting thereafter. The unheated control tumors on the contralateral legs showed a 10% +/- 3% signal increase within 2 minutes. Injection at 37 degrees C showed a continuous signal increase in "heated" and unheated tumors of up to 8% to 10%. Nonliposomal CA injection demonstrated that tumors were well perfused during HT. CONCLUSION:HT-induced CA release from Gd-TSL was monitored and characterized by MRI after i.v. injection in tumor-bearing mice. Higher temperatures resulted in higher signal changes. Immediately after i.v. injection, heated tumor tissue was distinguishable from unheated tumor tissue. The Gd-TSL appears to be suitable for MR monitoring of HT tumor treatment in a clinical MRI setting independent of field strength.
journal_name
Invest Radioljournal_title
Investigative radiologyauthors
Peller M,Schwerdt A,Hossann M,Reinl HM,Wang T,Sourbron S,Ogris M,Lindner LHdoi
10.1097/RLI.0b013e31818768cdsubject
Has Abstractpub_date
2008-12-01 00:00:00pages
877-92issue
12eissn
0020-9996issn
1536-0210pii
00004424-200812000-00008journal_volume
43pub_type
杂志文章abstract:RATIONALE AND OBJECTIVES:To evaluate the short-term effects of a new nitinol stent on canine arteries. METHODS:Eighteen nitinol mesh stents were placed in abdominal aortas, common iliac arteries, and renal arteries of six dogs. Angiography was performed to evaluate the patency rates and structural changes of arteries ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199905000-00007
更新日期:1999-05-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Optimal dose schedules and total dose of ionizing radiation for human central nervous system malignancy are not known. An animal model has been developed for the investigation of rat central nervous system response to proton irradiation using magnetic resonance imaging (MRI). A clinical MRI dev...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199504000-00003
更新日期:1995-04-01 00:00:00
abstract::The authors investigated the effect on the brain of red blood cells that had been modified by contrast media. Rat blood was mixed with an equivolume of contrast media, and up to 200 microL of the mixture was infused to the internal carotid artery of the rat. Evans blue was administered intravenously to assess the inte...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198905000-00009
更新日期:1989-05-01 00:00:00
abstract::Simultaneous inflation of two balloons may be necessary for balloon dilation valvuloplasty in patients with a large annulus. We examined the cardiovascular effects of dilating the pulmonary annulus with two balloons in 18 normal dogs using pulsed Doppler ultrasound and gross and microscopic examination. When the ratio...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198808000-00005
更新日期:1988-08-01 00:00:00
abstract::The authors compared the renal toxicity of the low osmolality radiocontrast agents, iohexol and ioxaglate, and the ionic agent, iothalamate, at equivalent iodine dose, using experimental models in vitro and in vivo. In isolated perfused rat kidneys, all agents induced comparable biphasic hemodynamic changes, associate...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199104000-00008
更新日期:1991-04-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Air microemboli may damage the cerebral microvasculature. The aim of this study was to evaluate the safety of ultrasound contrast agents composed of air microspheres with regard to cerebral damage when administered into the arterial system (ie, when not filtered by the capillary system of the l...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199803000-00001
更新日期:1998-03-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Emulsions of perfluorocarbons (PFCs) have been tested as blood substitutes. However, evidence exists that there is long-term retention of some PFCs by the organs of the reticuloendothelial system (RES). The authors investigate organ retention of the blood substitute component, perfluorotripropy...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199208000-00012
更新日期:1992-08-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:The purpose of this study evaluating a cesium iodide-amorphous silicon-based flat-panel detector was to optimize the x-ray spectrum for chest radiography combining excellent contrast-detail visibility with reduced patient exposure. MATERIALS AND METHODS:A Lucite plate with 36 drilled holes of ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000138091.96320.f8
更新日期:2004-10-01 00:00:00
abstract::Previous investigations in this laboratory have confirmed the observation of facial muscle twitching during intracarotid injections of nonionic contrast media (CM) in rabbits. The reaction appears to be a locally mediated effect. To further investigate this reaction, cortical electroencephalogram (EEG) and facial elec...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199009000-00010
更新日期:1990-09-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Two independent gold standards and diagnoses from three-dimensional computed tomography (CT) images were used to examine the possibility that craniosynostosis is a binary abnormality that potentially may be diagnosed without error. METHODS:Surgical reports, histology of excised sutures, and th...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199410000-00005
更新日期:1994-10-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To evaluate the safety and pharmacokinetics of a newly developed MR contrast medium consisting of very small superparamagnetic iron oxide particles (VSOP) coated with citrate (VSOP-C184) in a clinical phase I trial. METHODS:A total of 18 healthy subjects received either VSOP-C184 (core diamete...
journal_title:Investigative radiology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/01.rli.0000129472.45832.b0
更新日期:2004-07-01 00:00:00
abstract::A silicone gel phantom material is described. It can be molded into any shape and it can contain internal cavities. The material is selfsealing allowing the cavities to be filled with liquids. A simple geometric phantom consisting of a rectangular solid with a single internal spherical cavity was fabricated and imaged...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198702000-00013
更新日期:1987-02-01 00:00:00
abstract::The importance of evaluating medical student performance has been widely addressed in the medical education literature. Multiple-choice examinations are the preferred method of testing because they are easy to administer and score. Development of parallel or equivalent pre- and post-examinations provides objective inf...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:
更新日期:1986-09-01 00:00:00
abstract:OBJECTIVE:The objective of this study was to determine the gadolinium (Gd) concentration remaining in human bone tissue after administration of standard clinical doses of 2 Gd-based contrast agents: ProHance and Omniscan. MATERIALS AND METHODS:After administration of 0.1 mmol/kg of Gd chelate to patients undergoing hi...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000186569.32408.95
更新日期:2006-03-01 00:00:00
abstract:OBJECTIVE:The purpose of this study was to assess the diagnostic value and safety of the contrast agent gadoterate meglumine (Gd-DOTA, DOTAREM, Guerbet, Roissy CdG Cedex, France) in the setting of a postmarketing surveillance study. MATERIALS AND METHODS:Between January 2004 and October 2005, radiologists in 61 radiol...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000248893.01067.e5
更新日期:2007-01-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:The suitability of paramagnetic complexes as magnetic resonance contrast agents depends on various factors such as their relaxivity, stability, selectivity, and the inertness toward transmetallation by endogenous ions. The transmetallation of a series of 18 gadolinium complexes by the Zn2+ ion ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-200102000-00008
更新日期:2001-02-01 00:00:00
abstract::In this article, we propose a semiautomatic method for time-continuous contour detection in all phases of the cardiac cycle in magnetic resonance sequences. The method is based on multidimensional dynamic programming. After shape parameterization, cost hypercubes are filled with image-feature derived cost function val...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/01.rli.0000194070.88432.24
更新日期:2006-01-01 00:00:00
abstract:OBJECTIVES:The aims of this study were to present a deep learning approach for the automated classification of multiple sclerosis and its mimics and compare model performance with that of 2 expert neuroradiologists. MATERIALS AND METHODS:A total of 268 T2-weighted and T1-weighted brain magnetic resonance imagin scans ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000735
更新日期:2020-10-26 00:00:00
abstract::Low-dose transaxial tomography is a technique that can produce cross-sectional images of the hips and femurs in children to permit calculation of the angle of femoral anteversion. Transaxial tomography was compared with computed tomography in terms of measured radiation dose and image quality. Transaxial tomography wa...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:
更新日期:1985-12-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Validation of new positron emission tomography (PET) tracers or magnetic (MR) imaging contrast agents is based on isolated rodent heart preparations. The use of larger animals could provide a more direct validation using the devices used for humans. METHODS:An isolated pig heart preparation ha...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199711000-00010
更新日期:1997-11-01 00:00:00
abstract::The residency program at the University of Pennsylvania offers a 1-month fellowship for senior residents in medical student education. Instructional philosophy, methods, and content are discussed, observed, practiced, and evaluated. Close supervision and immediate feedback provide training particularly needed by futur...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199006000-00028
更新日期:1990-06-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To evaluate the feasibility of mechanical thrombectomy in occluded hemodialysis access shunts by using a newly developed 5F pigtail rotation catheter. METHODS:Thrombosed hemodialysis access shunts were simulated by clotted bovine blood in silicone tubing (diameter 6 mm). After retrograde and a...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199907000-00008
更新日期:1999-07-01 00:00:00
abstract::Over the past 120 years, continuous developments in medical imaging has improved diagnosis and treatment for many diseases and has thereby improved treatment outcome and quality of life of many patients. The number of computed tomography (CT) examinations is today increasing by 4% per year worldwide, for a total of ap...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/RLI.0000000000000696
更新日期:2020-09-01 00:00:00
abstract::We compared the damage resulting from intradermal injection of four commonly used radiographic contrast media in laboratory rats. Sixty percent meglumine diatrizoate (Reno M 60) and ioxaglate (Hexabrix) produced significantly more ulceration and crusting on gross inspection and more necrosis, edema, and hemorrhage on ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199005000-00006
更新日期:1990-05-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:To study cellular mechanisms that cause contrast media nephropathy, an in vitro system for proximal and distal tubular cells has been established to evaluate the influence of x-ray contrast media on tubular function. METHODS:Confluent cell cultures of the two renal cell lines, proximal tubule ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199411000-00002
更新日期:1994-11-01 00:00:00
abstract::Observer performance in radiologic interpretation has traditionally been based upon Receiver Operating Characteristic (ROC) analysis. A statistical method that evaluates the reproducibility or consistency of radiologic interpretation is presented. Since this method is not based upon pathologic verification, it cannot ...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198411000-00024
更新日期:1984-11-01 00:00:00
abstract:RATIONALE AND OBJECTIVES:Interstitial laser photocoagulation (ILP) causes localized tissue necrosis. This study was performed to determine 1) whether the changes seen on computed tomography (CT) correspond to the necrosis pathologically, and 2) which CT technique best shows the necrosis. METHODS:Eighteen Wistar rats h...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199312000-00014
更新日期:1993-12-01 00:00:00
abstract::Fractures modeled in the dried skull indicate that the initial plane of computed tomography (CT) section contributes to the accuracy of three-dimensional (3D) images generated from two-dimensional (2D) CT data. The authors retrospectively analyzed seven clinical cases of tripod zygomatic fractures that were imaged wit...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-199105000-00009
更新日期:1991-05-01 00:00:00
abstract::A photographic unsharp masking technique for improving the latitude of chest radiographs without sacrificing image contrast or detail is described. An unsharp mask film, prepared from a scout film of the patient's chest, is placed between the film and the front (entrance) screen in the cassette. A second radiograph th...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198107000-00007
更新日期:1981-07-01 00:00:00
abstract::We developed a new, cineangiographic method to accurately measure the dynamic changes in the internal diameter of human arteries in vivo. Cine films were digitized at a spatial resolution of 4 microns/pixel, using a line image sensor. The vessel edges, with a Gaussian fit to a unilateral profile curve of the vessel, w...
journal_title:Investigative radiology
pub_type: 杂志文章
doi:10.1097/00004424-198909000-00005
更新日期:1989-09-01 00:00:00