Investigative radiology
-
Investigative radiology · Jan 2009
Clinical TrialAdult Tetralogy of Fallot: quantitative assessment of pulmonary perfusion with time-resolved three dimensional magnetic resonance angiography.
To determine the potential role of dynamic temporally resolved three dimensional (3D) contrast-enhanced magnetic resonance angiography (MRA) for quantitative evaluation of pulmonary perfusion in adult patients with surgically treated Tetralogy of Fallot (ToF). ⋯ Time-resolved 3D contrast-enhanced MRA has potential for noninvasive and quantitative assessment of altered patterns of pulmonary perfusion in adult ToF, and may be a reliable technique for evaluation of postsurgical residua in these patients.
-
Investigative radiology · Dec 2008
MR characterization of mild hyperthermia-induced gadodiamide release from thermosensitive liposomes in solid tumors.
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. ⋯ 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.
-
Investigative radiology · Nov 2008
Clinical TrialLesion localization in patients with a previous negative transrectal ultrasound biopsy and persistently elevated prostate specific antigen level using diffusion-weighted imaging at three Tesla before rebiopsy.
To assess the use of diffusion-weighted imaging (DWI) at 3 Tesla (T) for lesion localization in patients with a high risk of prostate cancer before a rebiopsy. ⋯ DWI in addition to T2WI at 3 T has the potential to provide important information on lesion localization in patients that had both previous negative TRUS biopsy and persistently elevated prostate specific antigen levels before a repeated biopsy.
-
Investigative radiology · Nov 2008
Clinical TrialMultidetector computed tomography in reperfused acute myocardial infarction. Assessment of infarct size and no-reflow in comparison with cardiac magnetic resonance imaging.
(1) To determine the accuracy of delayed enhancement multidetector computed tomography (MDCT) in measuring the extent of acute myocardial infarct and no-reflow areas using cardiac magnetic resonance imaging (MRI) as standard of reference and (2) to define the optimum timing between injection and MDCT image acquisition to characterize infarcted myocardium and no-reflow areas after reperfusion therapy. ⋯ In ST segment elevation myocardial infarction patients contrast-enhanced MDCT is an accurate method for characterizing and sizing myocardial infarct and no-reflow. Contrast-enhanced MDCT performed 5 minutes after injection yields a higher signal-to-noise ratio and image quality than the 10 minutes time point with no difference in the extent of infarct measurement.
-
Investigative radiology · Nov 2008
Diagnostic accuracy of cardiac 64-slice computed tomography in detecting atrial thrombi. Comparative study with transesophageal echocardiography and cardiac surgery.
Atrial thrombi are a potential source for cerebral and peripheral emboli. Objective of this study was to evaluate the diagnostic accuracy of 64-slice cardiac computed tomography (CT) for detection of atrial thrombi in comparison with transesophageal echocardiography (TEE) and cardiac surgery. ⋯ Cardiac ECG-gated 64-slice CT is accurate to exclude atrial thrombi, which can be applied eg, in patients before radiofrequency (RF) ablation. Left atrial appendage "filling defects" cause a high number of false positive findings, and there are radiologic features, which are helpful to differentiate them from true thrombi.