Gadolinium-Enhanced Susceptibility-Weighted Imaging in Multiple Sclerosis: Optimizing the Recognition of Active Plaques for Different MR Imaging Sequences

Abstract

BACKGROUND AND PURPOSE: Gadolinium SWI is MR imaging that has recently been reported to be effective in the evaluation of several neurologic disorders, including demyelinating diseases. Our aim was to analyze the accuracy of gadolinium SWI for detecting the imaging evidence of active inflammation on MS plaques when a BBB dysfunction is demonstrated by a focal gadolinium-enhanced lesion and to compare this technique with gadolinium-enhanced T1 spin-echo and T1 spin-echo with magnetization transfer contrast. MATERIALS AND METHODS: MR imaging studies of 103 patients (170 examinations) were performed using a 1.5T scanner. Two neuroradiologists scrutinized signal abnormalities of the demyelinating plaques on gadolinium SWI and compared them with gadolinium T1 before and after an additional magnetization transfer pulse. Interrater agreement was evaluated among gadolinium T1 magnetization transfer contrast, gadolinium SWI, and gadolinium T1 spin-echo using the coefficient. The T1 magnetization transfer contrast sequence was adopted as the criterion standard in this cohort. Thus, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for gadolinium T1 spin-echo and gadolinium SWI sequences. RESULTS: Differences in BBB dysfunction were evident among gadolinium SWI, gadolinium T1 spin-echo, and gadolinium T1 magnetization transfer contrast. Gadolinium T1 magnetization transfer contrast demonstrated the highest number of active demyelinating plaques. Gadolinium SWI was highly correlated with gadolinium T1 magnetization transfer contrast in depicting acute demyelinating plaques (coefficient ϭ 0.860; sensitivity ϭ 0.837), and these techniques provided better performance compared with gadolinium T1 spin-echo (coefficient ϭ 0.78; sensitivity ϭ 0.645). CONCLUSIONS: Gadolinium SWI was able to better detect BBB dysfunction in MS plaques and had a better performance than gadolinium T1 spin-echo. Increasing SWI sequence applications in clinical practice can improve our knowledge of MS, likely allowing the addition of BBB dysfunction analysis to the striking findings of the previously reported central vein sign. ABBREVIATIONS: Gd ϭ gadolinium; MTC ϭ magnetization transfer contrast; SE ϭ spin-echo M ultiple sclerosis is a chronic and disabling demyelinating autoimmune disease that mainly affects young adults. MS is a multifactorial condition that probably results from the interaction among immunologic, genetic, and environmental factors, 1 predominantly characterized by the independent processes of inflammation, demyelination, neurodegeneration, remyelination, and axonal repair in different multifocal combinations at different stages of disease progression. MS is one of the most common neurologic disorders in the world and, in many countries, is the leading cause of nontraumatic neurologic disability in young adults. 2 MR imaging produces contrasts according to different tissues. Combined with its noninvasiveness, MR imaging has become the technique of choice for in vivo imaging of sever...

Blood Perfusion and Cellular Microstructural Changes Associated With Iron Deposition in Multiple Sclerosis Lesions

“…After being applied with phase information, it does not seem to be a standard T2 * contrast either. Although the non-iron laden isointense or hyperintense SWI lesions have been consistently shown in the literatures and represent most MS lesions (16, 17, 32, 33), their histopathological characteristics are unclear. In this study, we found most isointense Type-2 lesions on SWI are corresponding to isointense or hypointense (or black hole) lesions on T1-weighted imaging.…”

“…Based on QSM analysis, Zhang et al (26) showed gadolinium-enhancing MS lesions had relative low QSM values than non-enhancing lesions, which are consistent with the findings in this study that these enhancing lesions appear hyper- rather hypo-intense on SWI. Another study (32) has also demonstrated that enhancing lesions are likely to be hyperintensities in contrast to the central dark vein on post-gadolinium SWI images, despite that gadolinium is a paramagnetic agent and has strong T2 * shortening effect. These results suggest that signal intensities on SWI may help better detect BBB dysfunction and identify subtle inflammatory activities that are not detected on post-contrast T1-weighted imaging (35).…”

Recognition of Brain Metastases Using Gadolinium-Enhanced SWI MRI: Proof-of-Concept Study

“…SWI is therefore used routinely to evaluate a number of neurological conditions, including diffuse axonal injury, stroke, multiple sclerosis, or cerebral amyloid angiopathy, to name a few (10,11). Recent evidence suggests that gadolinium can be useful in susceptibility-weighted MRI (14) hypothetically by taking advantage of the so-called T1 shine-through effect (12), FIGURE 2 | Illustrative cases of lesions seen only with SWI-Gd. (A-C) MRI from a 45 years old female patient diagnosed with breast cancer and preexisting metastases on the right parieto-occipital region and a second one on the fifth left temporal gyrus.…”

“…Gadolinium enhancement has been used experimentally in SWI for evaluating primary gliomas, where it has shown promising results on staging, grading, and even determining the aggressiveness of primary brain tumors (13). SWI-Gd has been recently shown to be helpful for the detection of blood-brain barrier dysfunction in patients with multiple sclerosis (14), suggesting that it can also improve the imaging assessment of brain metastases. Hence, gadolinium enhancement in SWI (SWI-Gd) can potentially reveal certain characteristics of cerebral metastases not observed otherwise.…”

Improving acute demyelinating lesion detection: which T1-weighted magnetic resonance acquisition is more sensitive to gadolinium enhancement?

“…Contrast administration remains important in the detection of blood-brain barrier disruption, as well as being the gold standard MR technique to detect active inflammation in MS patients. Potential sequences that also require Gd-based contrast, recently been reported in the literature, are the double inversion recovery 38 and post-contrast susceptibility weighted imaging 39 . A new era of MRI research has also been developed for depicting the functionality of specific cells in the central nervous system through new contrast agents that have offered insight into the pathogenesis of MS in vivo; however, they are not yet available for routine clinical use 40 .…”