WBMRI and whole-spine MRI, both somewhat new techniques, are gaining ground in oncology for detection of metastasis, especially in pediatric populations because of their ability to scan the entire spine in only 1 session. They also are being used for spondyloarthropathy (SpA). Multiple phased-array surface coils are connected, negating the need to reposition the patient and making it possible to scan the entire spine in 2 planes in about 20 minutes. WBMRI detects inflammatory lesions outside the sacroiliac joints in a significant number of patients with SpA.
Several other factors support the use of whole-spine MRI in SpA. Whole-spine MRI and conventional MRI show similar results in detecting inflammatory lesions.10,11 Whole-spine MRI is important, because almost 23% of patients with SpA do not have sacroiliitis; therefore, a focused examination of sacroiliac joints could overlook a significant number of pathologies.
In a patient with amyloidosis involving the lumbosacral plexus, coronal maximum intensity projection 3D sagittal sampling perfection with application-optimized contrasts using different flip angle evolutions short tau inversion recovery sequences (A) and axial T2 spectral adiabatic inversion recovery sequences (B) show enlargement of the right L4 and L5 nerve roots (arrows) with amyloid depositions (arrow).
MRN is another application that exploits the higher SNR of 3 Tesla MRI. It consequently gives higher spatial and contrast resolution for evaluating peripheral nerve pathologies, ranging from plexus pathologies to more distal nerve pathologies. Strictly speaking, this technique is separate from spine MRI, but it complements spine imaging, because the cervical plexus and lumbosacral plexus are so closely related to the spine (Figure ).
In patients who have nonlocalizing or nonspecific symptoms and in whom spine imaging is noncontributory, MRN may show nerve abnormality related to injury or inflammation. Defining lesions preoperatively also is useful. In our institution, we use a combination of anatomical (T1-weighted) sequences and 2D and 3D fluid-sensitive sequences (STIR or SPAIR in combination with a 3D turbo spin-echo sequence).
Proton MRS is another technique that benefits from the higher SNR of 3 Tesla MRI. This approach adds metabolic information to the morphological imaging of the bone and soft tissue structures, including the spinal cord. Marliani and colleagues14 demonstrated the feasibility of proton MRS of the cervical spinal cord on 3 Tesla MRI overcoming the challenges from magnetic field heterogeneity around the spinal cord, respiratory and cardiac movement, and the small size of the spinal cord.
Functional (diffusion) imaging has been tested, and good accuracy in differentiating benign from malignant fractures has been reported. In addition, diffusion tensor imaging and tractography is feasible because it provides good fat-suppression techniques, better echo spacing, a higher SNR, and parallel imaging. Although anatomical imaging is useful for detecting macroscopic findings, diffusion tensor imaging provides a way to interrogate tissue microarchitecture and neural integrity.
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