Fast T1 Mapping Research Articles

Estimation of Perilymph Enhancement after Intratympanic Administration of Gd-DTPA by Fast T1-mapping with a Dual Flip Angle 3D Spoiled Gradient Echo Sequence

Eleven patients with suspected Ménière's disease received intratympanic (IT) administration of gadolinium (gadopentetate dimeglumine; Gd) prior to acquisition of 3-dimensional (3D) fluid-attenuated inversion recovery (FLAIR), 3D real inversion recovery (IR), and fast T₁ mapping by dual flip angle 3D gradient echo (FT₁-map) imaging sequences to evaluate the degree of perilymph enhancement. Though 3-dimensional FLAIR could detect lower concentrations of gadolinium than 3D real IR, in 2 patients, poor enhancement still prevented visualization of the endolymphatic space using 3D FLAIR. We could predict poor contrast enhancement in these 2 patients using the FT₁-map technique.

T2 relaxometry with indirect echo compensation from highly undersampled data

To develop an algorithm for fast and accurate T2 estimation from highly undersampled multi-echo spin-echo data. The algorithm combines a model-based reconstruction with a signal decay based on the slice-resolved extended phase graph (SEPG) model with the goal of reconstructing T2 maps from highly undersampled radial multi-echo spin-echo data with indirect echo compensation. To avoid problems associated with the nonlinearity of the SEPG model, principal component decomposition is used to linearize the signal model. The proposed CUrve Reconstruction via principal component-based Linearization with Indirect Echo compensation (CURLIE) algorithm is used to estimate T2 curves from highly undersampled data. T2 maps are obtained by fitting the curves to the SEPG model. Results on phantoms showed T2 biases (1.9% to 18.4%) when indirect echoes are not taken into account. The T2 biases were reduced (< 3.2%) when the CURLIE reconstruction was performed along with SEPG fitting even for high degrees of undersampling (4% sampled). Experiments in vivo for brain, liver, and heart followed the same trend as the phantoms. The CURLIE reconstruction combined with SEPG fitting enables accurate T2 estimation from highly undersampled multi-echo spin-echo radial data thus, yielding a fast T2 mapping method without errors caused by indirect echoes.

Quantification of blood-to-brain transfer rate in multiple sclerosis

Blood–brain barrier (BBB) disruption visualized in lesions by MRI is a major biomarker of disease activity in multiple sclerosis (MS). However, in MS, destruction occurs to a variable extent in lesions as well as in gray matter (GM) and in the normal appearing white matter (NAWM). A method to quantify the BBB disruption in lesions as well as in non-lesion areas would be useful for assessment of MS progression and treatments. The objective of this study was to quantify the BBB transfer rate (Ki) in WM lesions, in the NAWM, and in the full-brain of MS patients. Thirteen MS patients with active lesions and 10 healthy controls with age and gender matching were recruited for full-brain and WM Ki studies. Dynamic contrast-enhanced MRI (DCEMRI) scans were conducted using T1 mapping with partial inversion recovery (TAPIR), a fast T1 mapping technique, following administration of a quarter-dose of the contrast agent Gadolinium-DTPA (Gd-DTPA). The Patlak modeling technique was used to derive a voxel-based map of Ki. In all patients contrast-enhanced lesions, quantified by Ki maps, were observed. Compared with controls, patients with MS exhibited an increase in mean Ki of the full-brain (P-value<0.05) but no significant difference in mean Ki of NAWM. The identified increase in full-brain Ki of MS patients suggests a global vascular involvement associated with MS disease. The lack of observed significant decrease in Ki in NAWM suggests lower involvement of WM vasculature than full-brain vasculature in MS. Ki maps constructed from time series data acquired by DCEMRI provide additional information about BBB that could be used for evaluation of vascular involvement in MS and monitoring treatment effectiveness.

Evaluation of MR imaging with T1 and T2* mapping for the determination of hepatic iron overload

To evaluate MRI using T1 and T2* mapping sequences in patients with suspected hepatic iron overload (HIO). Twenty-five consecutive patients with clinically suspected HIO were retrospectively studied. All underwent MRI and liver biopsy. For the quantification of liver T2* values we used a fat-saturated multi-echo gradient echo sequence with 12 echoes (TR = 200ms, TE = 0.99ms + n × 1.41ms, flip angle 20°). T1 values were obtained using a fast T1 mapping sequence based on an inversion recovery snapshot FLASH sequence. Parameter maps were analysed using regions of interest. ROC analysis calculated cut-off points at 10.07ms and 15.47ms for T2* in the determination of HIO with accuracy 88%/88%, sensitivity 84%/89.5% and specificity 100%/83%. MRI correctly classified 20 patients (80%). All patients with HIO only had decreased T1 and T2* relaxation times. There was a significant difference in T1 between patients with HIO only and patients with HIO and steatohepatitis (P = 0.018). MRI-based T2* relaxation diagnoses HIO very accurately, even at low iron concentrations. Important additional information may be obtained by the combination of T1 and T2* mapping. It is a rapid, non-invasive, accurate and reproducible technique for validating the evidence of even low hepatic iron concentrations. • Hepatic iron overload causes fibrosis, cirrhosis and increases hepatocellular carcinoma risk. • MRI detects iron because of the field heterogeneity generated by haemosiderin. • T2* relaxation is very accurate in diagnosing hepatic iron overload. • Additional information may be obtained by T1 and T2* mapping.

Inhibition of the sodium-calcium exchanger via SEA0400 altered manganese-inducedT1changes in isolated perfused rat hearts

Manganese (Mn(2+) )-enhanced MRI (MEMRI) provides the potential for the in vivo evaluation of calcium (Ca(2+) ) uptake in the heart. Recent studies have also suggested the role of the sodium-calcium (Na(+) -Ca(2+) ) exchanger (NCX) in Mn(2+) retention, which may have an impact on MEMRI signals. In this study, we investigated whether MEMRI with fast T(1) mapping allowed the sensitive detection of changes in NCX activity. We quantified the dynamics of the Mn(2+) -induced T(1) changes in isolated perfused rat hearts in response to SEA0400, an NCX inhibitor. The experimental protocol comprised 30 min of Mn(2+) perfusion (wash-in), followed by a 30-min wash-out period. There were three experimental groups: 1, NCX inhibition by 1 µ m SEA0400 during Mn(2+) wash-in only (SEAin, n=6); 2, NCX inhibition by 1 µ m SEA0400 during Mn(2+) wash-out only (SEAout, n=6); 3, no NCX inhibition during both wash-in and wash-out to serve as the control group (CNTL, n=5). Rapid T(1) mapping at a temporal resolution of 3 min was performed throughout the perfusion protocol using a triggered saturation-recovery Look-Locker sequence. Our results showed that NCX inhibition during Mn(2+) wash-in caused a significant increase in relaxation rate (R(1) ) at the end of Mn(2+) perfusion. During the wash-out period, NCX inhibition led to less reduction in R(1) . Further analysis of Mn(2+) content in myocardium with flame atomic absorption spectroscopy was consistent with the MRI findings. These results suggest that Mn(2+) accumulation and retention in rat hearts are, in part, dependent on NCX activity. Hence, MEMRI may provide an imaging method that is also sensitive to changes in NCX activity.

Abstract 3725: Contrast Enhanced MRI with a Reduced Dose of Gadolinium for Measurement of Blood to Brain Influx Rate in Cerebrovascular Diseases

Dynamic Contrast-Enhanced MRI with a Reduced Dose of Gd-DTPA for Measurement of Blood-to-Brain Influx Rate in Cerebrovascular Diseases In vivo quantification of blood-to-brain transfer rate is of immense importance in diagnosis and monitoring cerebrovascular damages after stroke. Dynamic contrast-enhanced (DCE) methods in CT and MR have been used to collect data about the health of blood-brain barrier (BBB). However high dose of radiation in CT and high dose of contrast agent and long protocol time in MR limit the application of DCE methods in acute stroke imaging. The goal of this study was to investigate DCEMRI with a reduced dose of Gd-DTPA and reduced acquisition time for BBB quantification. Fifteen healthy subjects (23-85 years, 9M, 6F) were randomly divided into 4 groups. Each group received one of 4 different doses of Gd-DTPA (group I, 0.1mmol/Kg, n=4; group II, 0.05 mmol/Kg, n=4; group III, 0.025mmol/Kg, n=4; and group IV, 0.0125 mmol/kg, n=3) for DCEMRI. The MRI data acquisition was performed using a 1.5-Tesla Siemens whole-body scanner with a standard eight-channel array headcoil. Fast T1 sequence, TAPIR, was used to estimate the time-concentration of different doses of Gd-DTPA after IV bolus injection. In addition clinical laboratory data of time-dependent concentration of Gd-DTPA in plasma was obtained from contrast agent manufacturer. Clinical and MR-based data were analyzed for 1) nonlinearity effect of contrast on MR signal and 2) evaluate the percentage of MR sampling error. The reduced dose of Gd-DTPA was used to quantify the BBB transfer rate in 14 MS and 9 cerebral cavernous malformation patients recruited from other studies. Comparison of pharmaco dynamics of Gd-DTPA over a range of different initial doses (less than 0.1 mmol/Kg) shows that 1/4 of the standard dose renders less error in T1 sampling and provides a sufficient dynamics in the intensity of MR signal to achieve a shorter DCEMRI experiment. In comparison to the regular Gd-DTPA-enhanced images, the reduced dose of Gd-DTPA used in DCEMRI is more sensitive in BBB abnormality detection. Comparison of 4 different doses of Gd-DTPA showed that a dose of 25% of 0.1 mmol/Kg, when using a fast T1 mapping protocol, is optimal for BBB permeability quantification in patients. DCEMRI-based BBB influx rate measurements with reduced dose of contrast agent may offer a suitable and less risky biomarker for disease progression and drug trials. Imaging stroke; Left panel represent FLAIR anatomical image of patient with stroke. Right panel represents BBB transfer rate map.

Fast T1 mapping determined using incomplete inversion recovery look–locker 3D balanced SSFP acquisition and a simple two‐parameter model fit

To evaluate a fast T1 mapping technique using incomplete inversion recovery 3D balanced steady-state free precession acquisition along with a two-parameter model fit. Using Bloch simulations, we explored the two-parameter model fit for data acquired using such an acquisition scheme. The parameter space over which the fit holds good was determined through simulations. A linear correction was derived for the R1* (1/T1*) values so determined. Two phantoms and six volunteers were scanned using the described technique. Comparison scans using full recovery as well as gold standard inversion recovery spin echo were also performed. The two-parameter fit works exceedingly well over a large parameter space. T1 values in the phantoms showed an error of 4.9% and 39% before correction and 0.9% and 1.6% after correction. For the six volunteers, error in T1 value was 5.3% for white matter (WM) and 2.4% for gray matter (GM) after correction, while it was 11.2% and 18.2% before correction. The work presented here allows for T1 map determination with higher resolution and shorter acquisition time than previously possible. The technique is especially well suited for GM/WM T1 mapping.

Fast cardiac T1 mapping in mice using a model‐based compressed sensing method

Direct measurement of the longitudinal relaxation time T1 provides objective and quantitative diagnostic information. However, current T1 mapping methods are generally time consuming without the aid of fast imaging. This study used a model-based compressed sensing method for fast cardiac T1 mapping in small animals. Based on the physics of magnetization recovery, the aliasing artifact associated with under-sampling was removed by exploiting the sparsity of the signals in the T1 recovery direction. Simulation study was performed to evaluate the reconstruction accuracy under various experimental conditions. Several approaches that accounted for phase variations were compared for optimized reconstruction in the phantom study. In vivo validation was performed on a cardiac manganese-enhanced MRI study using mice. Accurate reconstruction of the under-sampled images and the resulting T1 maps were achieved in both simulation and MRI studies on phantom and in vivo mice. These results suggest that the current compressed sensing method allows fast (<80 s) T1 mapping of the mouse heart at high spatial resolution (234×469 μm2).

Quantitative measurement of blood-brain barrier permeability in human using dynamic contrast-enhanced MRI with fast T1 mapping

Breakdown of the blood-brain barrier (BBB), occurring in many neurological diseases, has been difficult to measure noninvasively in humans. Dynamic contrast-enhanced magnetic resonance imaging measures BBB permeability. However, important technical challenges remain and normative data from healthy humans is lacking. We report the implementation of a method for measuring BBB permeability, originally developed in animals, to estimate BBB permeability in both healthy subjects and patients with white matter pathology. Fast T1 mapping was used to measure the leakage of contrast agent Gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) from plasma into brain. A quarter of the standard Gd-DTPA dose for dynamic contrast-enhanced magnetic resonance imaging was found to give both sufficient contrast-to-noise and high T1 sensitivity. The Patlak graphical approach was used to calculate the permeability from changes in 1/T1. Permeability constants were compared with cerebrospinal fluid albumin index. The upper limit of the 95% confidence interval for white matter BBB permeability for normal subjects was 3 × 10−4 L/g min. MRI measurements correlated strongly with levels of cerebrospinal fluid albumin in those subjects undergoing lumbar puncture. Dynamic contrast-enhanced magnetic resonance imaging with low dose Gd-DTPA and fast T1 imaging is a sensitive method to measure subtle differences in BBB permeability in humans and may have advantages over techniques based purely on the measurement of pixel contrast changes. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc.

Quantitative in vivo measurement of early axonal transport deficits in a triple transgenic mouse model of Alzheimer's disease using manganese-enhanced MRI

Impaired axonal transport has been linked to the pathogenic processes of Alzheimer's disease (AD) in which axonal swelling and degeneration are prevalent. The development of non-invasive neuroimaging methods to quantitatively assess in vivo axonal transport deficits would be enormously valuable to visualize early, yet subtle, changes in the AD brain, to monitor the disease progression and to quantify the effect of drug intervention. A triple transgenic mouse model of AD closely resembles human AD neuropathology. In this study, we investigated age-dependent alterations of the axonal transport rate in the triple transgenic mouse olfactory system, using fast multi-sliced T1 mapping with manganese-enhanced MRI. The data show that impairment in axonal transport is a very early event in AD pathology in these mice, preceding both deposition of Aβ plaques and formation of Tau fibrils.

Variable flip angle-based fast three-dimensionalT1mapping for delayed gadolinium-enhanced MRI of cartilage of the knee: Need forB1correction

Delayed gadolinium-enhanced MRI of cartilage is a technique, which involves T(1) mapping to identify changes in the structural integrity of cartilage associated with osteoarthritis. Currently, the gold standard is 2D inversion recovery turbo spin echo, which suffers from long acquisition times and limited coverage. Three-dimensional variable flip angle (VFA) is an alternate technique, which has been shown to be accurate when an estimate of T(1) is available a priori. This study validates the variable flip angle method for delayed gadolinium-enhanced MRI of cartilage of the femoro-tibial knee cartilage. When amplitude of (excitation) radiofrequency field inhomogeneities were minimized using nonselective pulses and amplitude of (excitation) radiofrequency field correction using an additional acquisition of a amplitude of (excitation) radiofrequency field map, the accuracy of T(1) measurements were improved, and slice-to-slice variations over the 3D volume were minimized. In conclusion, fast 3D T(1) mapping using the variable flip angle method with amplitude of (excitation) radiofrequency field correction appears to be an efficient and accurate method for delayed gadolinium-enhanced MRI of cartilage of the knee.

High resolution fast T1 mapping technique for dGEMRIC

To determine the feasibility of using a high resolution isotropic three-dimensional (3D) fast T1 mapping sequence for delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) to assess osteoarthritis in the hip. T1 maps of the hip were acquired using both low and high resolution techniques following the administration of 0.2 mmol/kg Gd-DTPA(2-) in 35 patients. Both T1 maps were generated from two separate spoiled GRE images. The high resolution T1 map was reconstructed in the anatomically equivalent plane as the low resolution map. T1 values from the equivalent anatomic regions containing femoral and acetabular cartilages were measured on the low and high resolution maps and compared using regression analysis. In vivo T1 measurements showed a statistically significant correlation between the low and high resolution acquisitions at 1.5 Tesla (R(2) = 0.958, P < 0.001). These results demonstrate the feasibility of using a fast two-angle T1 mapping (F2T1) sequence with isotropic spatial resolution (0.8 x 0.8 x 0.8 mm) for quantitative assessment of biochemical status in articular cartilage of the hip. The high resolution 3D F2T1 sequence provides accurate T1 measurements in femoral and acetabular cartilages of the hip, which enables the biochemical assessment of articular cartilage in any plane through the joint. It is a powerful tool for researchers and clinicians to acquire high resolution data in a reasonable scan time (< 30 min).

Delayed Gadolinium-enhanced MR Imaging of Articular Cartilage: Three-dimensional T1 Mapping with Variable Flip Angles and B1Correction

To develop and verify the accuracy of a rapid imaging protocol for delayed gadolinium-enhanced magnetic resonance (MR) imaging of cartilage that was based on three-dimensional (3D) spoiled gradient-recalled acquisition in the steady state (SPGR) sequences with variable flip angles (FAs) (VFAs) and where a correction method for B(1) field inhomogeneities was applied. The institutional research ethics board approved this study. Written informed consent was obtained from all subjects. A B(1) field inhomogeneity correction method was applied to a 3D SPGR pulse sequence with VFAs (repetition time msec/echo time msec, 7.1/3.3; FAs, 2 degrees , 5 degrees , 10 degrees , and 20 degrees ) and was used to perform delayed gadolinium-enhanced MR imaging of cartilage 3D T1 measurements at 1.5 T. The 3D T1 measurements were validated with the reference standard (the results of T1 mapping by using a single-section two-dimensional [2D] inversion-recovery [IR] fast spin-echo [SE] pulse sequence in vitro and in vivo) in six healthy volunteers. T1 values calculated from 3D T1 maps were not significantly different from reference T1 values in vitro (P = .195) and in vivo (P = .52) when a B(1) field inhomogeneity correction method was applied. In vivo T1 mapping of the articular surface of the whole femoropatellar joint, including data acquisition, was performed in approximately 8 minutes of acquisition time at a spatial resolution of 0.55 x 0.55 x 3.00 mm. Rapid T1 mapping by using 3D SPGR acquisitions with a VFA approach and a correction for B(1) field inhomogeneities can be used for delayed gadolinium-enhanced MR imaging of cartilage. T1 measurements performed in vitro and in vivo by using this approach are highly accurate when compared with those performed by using standard 2D IR fast SE T1 mapping as a reference.

Fast Whole-Brain T1 Mapping at 1 mm Resolution with RF Bias Correction

Fast Whole-Brain T1 Mapping at 1 mm Resolution with RF Bias Correction

Comparison of delayed gadolinium enhanced MRI of cartilage (dGEMRIC) using inversion recovery and fast T1 mapping sequences

The delayed Gadolinium Enhanced MRI of Cartilage (dGEMRIC) technique has shown promising results in pilot clinical studies of early osteoarthritis. Currently, its broader acceptance is limited by the long scan time and the need for postprocessing to calculate the T1 maps. A fast T1 mapping imaging technique based on two spoiled gradient echo images was implemented. In phantom studies, an appropriate flip angle combination optimized for center T1 of 756 to 955 ms yielded excellent agreement with T1 measured using the inversion recovery technique in the range of 200 to 900 ms, of interest in normal and diseased cartilage. In vivo validation was performed by serially imaging 26 hips using the inversion recovery and the Fast 2 angle T1 mapping techniques (center T1 756 ms). Excellent correlation with Pearson correlation coefficient R2 of 0.74 was seen and Bland-Altman plots demonstrated no systematic bias.

Fast T2 mapping of the patellar articular cartilage with gradient and spin-echo magnetic resonance imaging at 1.5 T: validation and initial clinical experience in patients with osteoarthritis

To evaluate the T2 mapping of patellar articular cartilage in patients with osteoarthritis using gradient and spin-echo (GRASE) magnetic resonance (MR) imaging. After the imaging of a phantom consisting of two sealed 50-ml test objects with different concentrations (30% and 90% weight/volume) of copper sulphate, the T2 mapping of patellar articular cartilage was performed in 35 patients (21 male and 14 female; mean age +/- SD 42+/-17 years) with moderate degree of patellar osteoarthritis. Turbo-spin-echo (TSE) (TR milliseconds/ minimum-maximum TE milliseconds 3,000/15-120; total acquisition time 5 min 52 s) and GRASE (TR milliseconds/ minimum-maximum TE milliseconds 3,000/15-120; total acquisition time 1 min 51 s) were employed. In each patient patellar cartilage was segmented at nine locations (three superior, three central, and three inferior) by manually defined regions of interest. T2 relaxation times were calculated using a linear fit applied to the logarithm of signal intensity decay. In the phantom the T2 values measured by GRASE were similar to those measured by MR spectroscopy (test object 1: 48.1 ms vs 51 ms; test object 2: 66.8 ms vs 71 ms; P>0.05, Wilcoxon test). In patients GRASE and TSE-derived T2 values demonstrated good agreement (mean difference +/- SD, 1.81+/-3.63 ms). The within-patient coefficient of variation was 22% for TSE and 23% for GRASE. Fast T2 mapping of the patellar articular cartilage can be performed with GRASE within a third of the time of that of standard sequences.

Brain Redox Imaging Using Blood—Brain Barrier-Permeable Nitroxide MRI Contrast Agent

Reactive oxygen species (ROS) and compromised antioxidant defense may contribute to brain disorders such as stroke, amyotrophic lateral sclerosis, etc. Nitroxides are redox-sensitive paramagnetic contrast agents and antioxidants. The ability of a blood-brain barrier (BBB)-permeable nitroxide, methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (MC-P), as a magnetic resonance-imaging (MRI) contrast agent for brain tissue redox imaging was tested. MC-P relaxation in rodent brain was quantified by MRI using a fast Look-Locker T(1)-mapping sequence. In the cerebral cortex and thalamus, the MRI signal intensity increased up to 50% after MC-P injection, but increased only by 2.7% when a BBB-impermeable nitroxide, 3CxP (3-carboxy-2,2,5,5,5-tetramethylpyrrolidine-1-oxyl) was used. The maximum concentrations in the thalamus and cerebral cortex after MC-P injection were calculated to be 1.9+/-0.35 and 3.0+/-0.50 mmol/L, respectively. These values were consistent with the ex vivo data of brain tissue and blood concentration obtained by electron paramagnetic resonance (EPR) spectroscopy. Also, reduction rates of MC-P were significantly decreased after reperfusion following transient MCAO (middle cerebral artery occlusion), a condition associated with changes in redox status resulting from oxidative damage. These results show the use of BBB-permeable nitroxides as MRI contrast agents and antioxidants to evaluate the role of ROS in neurologic diseases.

Optimization and validation of a fully‐integrated pulse sequence for modified look‐locker inversion‐recovery (MOLLI) T1 mapping of the heart

To optimize and validate a fully-integrated version of modified Look-Locker inversion-recovery (MOLLI) for clinical single-breathhold cardiac T1 mapping. A MOLLI variant allowing direct access to all pulse sequence parameters was implemented on a 1.5T MR system. Varying four critical sequence parameters, MOLLI was performed in eight gadolinium-doped agarose gel phantoms at different simulated heart rates. T1 values were derived for each variant and compared to nominal T1 values. Based on the results, MOLLI was performed in midcavity short-axis views of 20 healthy volunteers pre- and post-Gd-DTPA. In phantoms, a readout flip angle of 35 degrees , minimum TI of 100 msec, TI increment of 80 msec, and use of three pausing heart cycles allowed for most accurate and least heart rate-dependent T1 measurements. Using this pulse sequence scheme in humans, T1 relaxation times in normal myocardium were comparable to data from previous studies, and showed narrow ranges both pre- and postcontrast without heart rate dependency. We present an optimized implementation of MOLLI for fast T1 mapping with high spatial resolution, which can be integrated into routine imaging protocols. T1 accuracy is superior to the original set of pulse sequence parameters and heart rate dependency is avoided.

Fast T1 mapping on a whole-body scanner.

A method for the fast acquisition of quantitative T1 maps is presented. It is based on the acquisition of a series of snapshot fast low-angle shot (FLASH) images after inversion of the magnetization. A drawback of this method is the necessity for a sufficiently long relaxation delay before each inversion pulse, leading to long experimental times if averaging or segmentation is required. Thus implementation of this method on a whole-body scanner is problematic, as the longer gradient rise times provide prolonged repetition times, which makes segmentation indispensable to provide a sufficient temporal resolution. We present a modification of the method that allows for reduction in the intermediate relaxation delays and thus for considerably reduced experimental durations.

Fast T2-mapping with SNAPSHOT FLASH imaging

It has been shown recently that quantitative T2-maps may be measured by acquisition of a series of at least eight T2-weighted SNAPSHOT FLASH images. These measurements require a relaxation delay of 10-15 s after each T2-weighted image for the complete relaxation of the spin system. This results in long measuring times. The method presented in this paper allows a considerable reduction of the measuring time by combining the T2-sequence with a fast T1-measurement. Quantitative T1- and T2-maps may be acquired simultaneously in less than 30 s. The method was tested in a phantom experiment. In an in vivo application, relaxation times of different tissues in the abdomen of a rat were measured.