Search results for "Perfusion Imaging"

Dynamic contrast-enhanced myocardial perfusion imaging using saturation-prepared TrueFISP.

2002

Purpose To develop and test a saturation-recovery TrueFISP (SR-TrueFISP) pulse sequence for first-pass myocardial perfusion imaging. Materials and Methods First-pass magnetic resonance imaging (MRI) of Gd-DTPA (2 mL) kinetics in the heart was performed using an SR-TrueFISP pulse sequence (TR/TE/α = 2.6 msec/1.4 msec/55°) with saturation preparation TD = 30 msec before the TrueFISP readout. Measurements were also performed with a conventional saturation-recovery TurboFLASH (SRTF) pulse sequence for comparison. Results SR-TrueFISP images were of excellent quality and demonstrated contrast agent wash-in more clearly than SRTF images. The signal increase in myocardium was higher in SR-TrueFISP …

Comparison of three accelerated pulse sequences for semiquantitative myocardial perfusion imaging using sensitivity encoding incorporating temporal f…

2007

Purpose To investigate the parallel acquisition technique sensitivity encoding incorporating temporal filtering (TSENSE) with three saturation-recovery (SR) prepared pulse sequences (SR turbo fast low-angle shot [SR-TurboFLASH], SR true fast imaging with steady precession [SR-TrueFISP], and SR-prepared segmented echo-planar-imaging [SR-segEPI]) for semiquantitative first-pass myocardial perfusion imaging. Materials and Methods In blood- and tissue-equivalent phantoms the relationship between signal intensity (SI) and contrast-medium concentration was evaluated for the three pulse sequences. In volunteers, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and normalized upslopes (N…

Quantitative myocardial perfusion imaging using different autocalibrated parallel acquisition techniques

2008

Purpose To compare three different autocalibrated parallel acquisition techniques (PAT) for quantitative and semiquantitative myocardial perfusion imaging. Materials and Methods Seven healthy volunteers underwent myocardial first-pass perfusion imaging at rest using an SR-TrueFISP pulse sequence without PAT and while using GRAPPA, mSENSE, and TSENSE. signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), normalized upslopes (NUS), and myocardial blood flow (MBF) were calculated. Artifacts, image noise, and overall image quality were qualitatively assessed. Furthermore, the relation between signal intensity (SI) and contrast medium (CM) concentration was determined in phantoms. Results …

Pharmacological stress, rest perfusion and delayed enhancement cardiac magnetic resonance identifies very early cardiac involvement in systemic scler…

2017

Objective To evaluate occult cardiac involvement in asymptomatic systemic sclerosis (SSc) patients by pharmacological stress, rest perfusion and delayed enhancement cardiac magnetic resonance (CMR), for a very early identification of patients at higher risk of cardiac-related mortality. Methods Sixteen consecutive patients with definite SSc, fulfilling the American College of Rheumatology/European League Against Rheumatism 2013 classification criteria in less than 1 year from the onset of Raynaud's phenomenon, underwent pharmacological stress, rest perfusion and delayed enhancement CMR. At enrollment, no patient showed signs and/or symptoms suggestive for cardiac involvement. No patient sho…

Stable microvascular angina: instrumental evaluation of coronary microvascular dysfunction with coronary angiography and myocardial scintigraphy

2014

Myocardial Perfusion and Fractional Flow Reserve

2013

Myocardial CT perfusion imaging is a rapidly evolving technology that allows assessment of the functional significance of potentially obstructive coronary stenosis. The opportunity for quantification of myocardial perfusion is the greatest potential advantage of CT compared with other perfusion techniques. On the other hand, fractional flow reserve during coronary angiography provides a functional assessment of coronary lesions identified with this modality. Recently, a non-invasive method for estimating fractional flow reserve, based on coronary CT angiography has been introduced. Nevertheless, at present neither CT perfusion nor CT FFR are ready for widespread use in clinical routine.

Quantification of Myocardial Blood Flow Using Magnetic Resonance Imaging with Different accelerated Pulse Sequences

2009

The aim of this study was to compare SRTurboFLASH, SR-TrueFISP, and SR-segEPI pulse sequences using a twofold TSENSE-acceleration with regard to their use in quantification of myocardial blood flow (MBF). Six healthy volunteers were examined at 1.5T by first pass myocardial perfusion MRI at rest using all three TSENSE-accelerated pulse sequences. For absolute quantifi-cation of MBF XSIM software with the MMID4 model has been used. MBF analyses revealed significant MBF differences between SRTurboFLASH and SR-segEPI compared to SR-TrueFISP (p<0.005 and p<0.001, respectively). Differences between SRTurboFLASH and SR-segEPI were not statistically significant. The median MBF values for SR-TurboF…

Quantification of pulmonary blood flow (PBF): validation of perfusion MRI and nonlinear contrast agent (CA) dose correction with H(2)15O positron emi…

2009

Validation of quantification of pulmonary blood flow (PBF) with dynamic, contrast-enhanced MRI is still missing. A possible reason certainly lies in difficulties based on the nonlinear dependence of signal intensity (SI) from contrast agent (CA) concentration. Both aspects were addressed in this study. Nine healthy pigs were examined by first-pass perfusion MRI using gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) and HO positron emission tomography (PET) imaging. Calculations of hemodynamic parameters were based on a one-compartment model (MR) and a two-compartment model (PET). Simulations showed a significant error when assuming a linear relation between MR SI and CA dose in the …

Non invasive blood flow measurement in cerebellum detects minimal hepatic encephalopathy earlier than psychometric tests

2013

AIM: To assess whether non invasive blood flow measurement by arterial spin labeling in several brain regions detects minimal hepatic encephalopathy. METHODS: Blood flow (BF) was analyzed by arterial spin labeling (ASL) in different brain areas of 14 controls, 24 cirrhotic patients without and 16 cirrhotic patients with minimal hepatic encephalopathy (MHE). Images were collected using a 3 Tesla MR scanner (Achieva 3T-TX, Philips, Netherlands). Pulsed ASL was performed. Patients showing MHE were detected using the battery Psychometric Hepatic Encephalopathy Score (PHES) consisting of five tests. Different cognitive and motor functions were also assessed: alterations in selective attention we…

Prevalence and prognostic impact of nonischemic late gadolinium enhancement in stress cardiac magnetic resonance

2020

Aim To assess the prevalence and prognostic significance of NI-LGE in patients undergoing stress-CMR. Methods Stress-CMR with either dipyridamole or adenosine was performed in 283 patients (228 men, 81%) including perfusion imaging, wall motion evaluation and LGE. Follow-up was completed in all enrolled patients (median time: 1850 days; interquartile range: 1225-2705 days). Composite endpoint included cardiac death, ventricular tachycardia, myocardial infarction, stroke, hospitalization for cardiac cause and coronary revascularization performed beyond 90 days from stress-CMR scans. Results One hundred and twelve patients (40%) had negative LGE (no-LGE), 140 patients (49%) I-LGE and 31 patie…