Focused Abbreviated Survey MRI Protocols for Brain and Spine Imaging.

There has been extensive growth in both the technical development and the clinical applications of MRI, establishing this modality as one of the most powerful diagnostic imaging tools. However, long examination and image interpretation times still limit the application of MRI, especially in emergent clinical settings. Rapid and abbreviated MRI protocols have been developed as alternatives to standard MRI, with reduced imaging times, and in some cases limited numbers of sequences, to more efficiently answer specific clinical questions. A group of rapid MRI protocols used at the authors' institution, referred to as FAST (focused abbreviated survey techniques), are designed to include or exclude emergent or urgent conditions or screen for specific entities. These FAST protocols provide adequate diagnostic image quality with use of accelerated approaches to produce imaging studies faster than traditional methods. FAST protocols have become critical diagnostic screening tools at the authors' institution, allowing confident and efficient confirmation or exclusion of actionable findings. The techniques commonly used to reduce imaging times, the imaging protocols used at the authors' institution, and future directions in FAST imaging are reviewed to provide a practical and comprehensive overview of FAST MRI for practicing neuroradiologists. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Imaging approach to the cord T2 hyperintensity (myelopathy).

In clinically suspected cases of myelopathy, magnetic resonance imaging without and with gadolinium remains the modality of choice. The first and best imaging approach in the evaluation of myelopathy is to identify whether the cause of myelopathy is compressive or noncompressive. The commonest imaging finding in myelopathy is either focal or diffuse cord hyperintensity on the T2-weighted magnetic resonance images. Detailed clinical history, acuity of symptoms (acute vs insidious onset), distribution of the signal abnormalities, including length of cord involvement, specific tract involvement, and the region of the spinal cord that is affected, are very useful in making the diagnosis.

Presurgical localization of parathyroid adenomas with magnetic resonance imaging at 3.0 T: an adjunct method to supplement traditional imaging.

PURPOSE: To investigate the use of a chemical shift-based water-fat separation magnetic resonance imaging (MRI) method, and time-resolved contrast-enhanced MRI at 3 T for improved presurgical localization of parathyroid adenomas. METHODS: Twenty-five patients with primary hyperparathyroidism were prospectively enrolled. Patients underwent MRI, which was reviewed by two experienced neuroradiologists who were blinded to Tc-99m sestamibi imaging and operative results. RESULTS: Overall, MRI detected 16 adenomas in 25 patients (sensitivity 64%, positive predictive value 67%), while sestamibi detected 18 of 25 adenomas (sensitivity 72%, positive predictive value 90%). Importantly, MRI was able to detect adenomas in four (57%) of the seven patients whose disease was missed by sestamibi analysis. MRI demonstrated excellent image quality and fat suppression by using a chemical shift-based water-fat separation technique. The time-resolved MRI was considered to be less helpful, although in some cases it was indispensable. CONCLUSIONS: MRI is an excellent adjunct for preoperative parathyroid localization. The advent of improved fat suppression techniques in the neck, including chemical shift-based water-fat separation, is critical to its utility. Although time-resolved MRI was not always helpful, it was crucial in certain cases. It may prove to be more useful with the development of faster scanning techniques.

Noninvasive dynamic magnetic resonance angiography with Time-Resolved Imaging of Contrast KineticS (TRICKS) in the evaluation of orbital vascular lesions.

OBJECTIVE: To evaluate the clinical utility of time-resolved contrast-enhanced magnetic resonance angiography (MRA) in the evaluation of vascular orbital tumors. METHODS: Retrospective medical record review of patients with vascular orbital lesions imaged with Time-Resolved Imaging of Contrast KineticS (TRICKS; GE Healthcare [Chalfont St Giles, England]) MRA, a noninvasive dynamic imaging modality. RESULTS: Five patients with orbital vascular tumors were evaluated using TRICKS MRA. These included 1 patient with a cavernous hemangioma, 2 patients with orbital varices, 1 patient with an orbitocutaneous arteriovenous malformation, and 1 patient who had a solitary fibrous tumor with features of a hemangiopericytoma. In 2 patients, diagnoses were altered as a result of TRICKS MRA. In addition, a young patient with a large orbitocutaneous arteriovenous malformation involving the ophthalmic artery was followed perioperatively and noninvasively using TRICKS MRA, which produced exquisite images and added substantial value in the care of these patients. CONCLUSION: Dynamic MRA in the form of TRICKS is a newly available imaging modality with great potential for improving the evaluation and management of patients with complex orbital tumors.