The diagnostic image quality of contrast-enhanced (CE) 3D MR venography (MRV) was prospectively compared with that of 2D time-of-flight (TOF) MRV and contrast-enhanced 3D magnetization-prepared rapid acquisition of gradient echo (MPRAGE) sequences for the visualization of the intracranial venous system at 3T in 22 patients. CE MRV provides high-quality images and was shown to be superior to TOF...

Highlights: • Magnetic resonance imaging has become a viable imaging modality for clinical use in the detection of pulmonary embolism (PE) • Low flip angle T1-weighted 3D gradient echo sequences, combined with noncontrast steady state free precession sequences, improve detection rate for PE compared with MR angiography alone • Newer image acquisition methods that correct for motion artifact all...

Virtually all MRI sequences produce images with some degree of T1 weighting, in fact probably the only sequence that has no T1 weighting would be a single RF pulse acquisition such as gradient echo EPI performed in isolation (with an infinite TW). Therefore in principle the vast majority of pulse sequences could be used to measure T1 by simply adjusting their timing or flip angles to change the...

MRI uses the magnetic properties of the hydrogen atoms present in the human body. It presents no risks as long as the contraindications (pacemaker, metal fragment in the eye, pregnancy less than 3 months) are complied with. MRI is the reference imaging method for exploration of the brain. The contrast of these images depends on the type of sequence used. More specific sequences (diffusio-weight...

New ultrafast gradient systems and hybrid imaging sequences make it possible to acquire a complete image in real time, without the need for breathholding or electrocardiogram (ECG) triggering. In 21 patients, left ventricular function was assessed by the use of a turbo-gradient echo technique, an echo-planar imaging (EPI) technique, and a new real-time imaging technique. End-diastolic and end-s...

A simple theoretical model was developed to compare the sensitivities (i.e., signal-to-noise ratios per unit imaging time) of two-dimensional (2D) multislice and 3D imaging sequences. The model shows that the sensitivities of 3D and 2D multislice MRI sequences are usually similar. Sensitivities are identical in T2-weighted sequences when the T(R)s of the two sequences are the same. In T1-weight...

Introduction: Transverse relaxation in living tissue can be used as a probe of tissue structure. Vessel size imaging [1-3] is a realization of this potential: The mean size of microvessels can be evaluated by comparison of the gradient echo and spin echo amplitudes. In practical implementation, it is often convenient to use multiple refocusing pulses (CPMG-type measurement) instead of a single ...

The objective of this study was to evaluate fast and ultrafast T2-weighted images (T2WI), including echo planar imaging (EPI), using an AMI-25 agar phantom. Image quality for conventional spin echo (CSE) and turbo spin echo (TSE) was almost equivalent. In high-resolution TSE, image quality was highest due to the use of a 512 x 256 matrix. Half-Fourier single-shot turbo SE (HASTE) was associated...

PURPOSE Stereotactic pallidotomy, which has evolved as a result of technological advances in high-resolution MR imaging and microelectrode electrophysiological recording, is becoming a major form of treatment for patients with Parkinson disease in whom medical therapy has failed. We describe the location and appearance of the pallidotomy lesion on high-resolution MR images. METHODS MR images ...