Time-of-flight MRA is mainly used to characterize luminal abnormality and act as a localizer for subsequent vessel wall sequences. Ongoing advances in MR imaging technology, including higher magnetic field strength, 2 may enable further increases in spatial resolution and image quality. Most experienced centers are using isotropic voxel dimensions in the 0.4- to 0.7-mm range for 3D acquisitions. At 3T with a 3D sequence, a voxel size of 0.5 mm isotropic is a reasonable starting point ( Fig 1 B), and it is possible to cover the circle of Willis and second-/third-order branches in 7–10 minutes. At 3T with a 2D sequence, a voxel size of 2.0 × 0.4 × 0.4 mm provides a reasonable balance between spatial resolution and signal-to-noise ratio, with a scan duration of approximately 5–7 minutes for a 2- to 4-cm-thick section of tissue ( Fig 1 A). The higher signal-to-noise ratio at 3T than at 1.5T is advantageous for intracranial VW-MR imaging and, in many cases, necessary. In addition, vessel wall disease often results in wall thickening, which increases its conspicuity. However, it is possible to image the intracranial arterial wall because the wall generates detectable MR imaging signal and one can suppress the MR imaging signal arising from neighboring blood and CSF within the voxel. The normal middle cerebral artery and basilar artery wall thickness is 0.2–0.3 mm, which is approximately one-tenth of the luminal diameter 1 and smaller than the VW-MR imaging voxel dimensions currently achievable. The principal technical requirements for intracranial VW-MR imaging are the following: 1) high spatial resolution, 2) multiplanar 2D acquisitions or 3D acquisitions, 3) multiple tissue weightings, and 4) suppression of signal in luminal blood and CSF. The technical sections that follow provide general recommendations on the development of an intracranial VW-MR imaging protocol, and we are also launching a dynamic document (via the American Society of Neuroradiology Web site) through which experienced centers can describe their MR imaging systems and the specific pulse sequences and scan parameters that they have found useful. Selection of sequences and scan parameters for VW-MR imaging is highly dependent on the particular scanner hardware and software available at a center. Until such sequences are widely available, it is possible to adjust the scan parameters of existing sequences and obtain vessel wall images of sufficient quality for clinical use. Noise levels are reduced by up to 90%, alleviating patients' No.The American Society of Neuroradiology Vessel Wall Imaging Study Group is working with MR imaging vendors to promote the development and dissemination of commercial pulse sequences that are optimized for intracranial VW-MR imaging. 70% of procedures can be performed feet-first, with the patient's head remaining outside the imaging bore.The ultra-short open-bore is 20% larger than similar systems.Provides higher quality MRI breast exams and biopsies.Strongest magnet in the area - produces high-quality images faster.McLaren Central Michigan also offers more sedation options for pediatric and extremely claustrophobic patients. It also provides higher quality MRI breast exams and biopsies, as well as exams focusing on blood vessels without the use of contrast dyes. New technology offers a dramatic reduction in acoustic noise for an improved patient experience, and motion correction software helps to eliminate involuntary patient motion during exams. It allows feet-first imaging capabilities for shoulder, lumbar and thoracic spine exams. Providing plenty of shoulder and breathing room, there is more space around the patient's head, limiting the time they are fully enclosed. This type of MRI can accommodate patients small and large and has a table that can support up to 440 pounds. The patient-friendly features comfort patients with claustrophobia, as the system we utilize has one of the largest and widest open bores available, nearly 20 percent larger than similar systems. Using the latest development in imaging equipment, open bore MRI offers a more comfortable exam experience for patients while allowing medical staff to conduct high-quality MR imaging. This clarity makes it the most sensitive exam for spinal and joint problems and is also used to diagnose and evaluate internal organs for various diseases and disorders. MRI generates very clear images of soft-tissue structures near and around bones that other imaging techniques, such as X-ray, cannot produce. MRI units are large, non-invasive devices that use radio waves and a strong magnetic field to provide clear, detailed images of internal organs and tissues.
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