Written informed consent was obtained prior to all human studies after the institutional review board approved the protocol. A continuous arterial spin-labeling technique with an amplitude-modulated control was implemented by using a single coil at 3.0 T. Adiabatic inversion efficiency at 3.0 T, comparable to that at 1.5 T, was achieved by reducing the amplitude of radiofrequency pulses and gradient strengths appropriately. The amplitude-modulated control provided a good match for the magnetization transfer effect of labeling pulses, allowing multisection perfusion magnetic resonance imaging of the whole brain. Comparison of multisection continuous and pulsed arterial spin-labeling methods at 3.0 T showed a 33% improvement in signal-to-noise ratio by using the former approach.

RFA can effectively eliminate low-risk PTMC with a very small complication rate. RFA may be an alternative strategy for the treatment of PTMC.

Background and Purpose Magnetic susceptibility values of multiple sclerosis (MS) lesions increase as they change from gadolinium (Gd) enhancing to non-enhancing. Can susceptibility values measured on quantitative susceptibility mapping (QSM) without Gd injection be used to identify the status of lesion enhancement in surveillance MRI used to monitor MS patients? Materials and Methods In patients who had a prior MRI and are having QSM in a current MRI, new T2-weighted lesions were evaluated for enhancement on a conventional T1-weighted with Gd, and their susceptibility values were measured on QSM. Receiver-operating-characteristics (ROC) analysis was used to assess the diagnostic accuracy of using QSM in distinguishing new Gd enhancing from new non-enhancing lesions. A generalized estimated equation was used to assess difference in susceptibility values between lesion types. Results In 54 patients, we identified 86 out of 133 new lesions that were Gd enhancing and had relative susceptibility values significantly lower than those of non-enhancing lesions (β=−17.17(−20.2 to −14.2), p <.0001). Using susceptibility values to discriminate enhancing from non-enhancing lesions, we performed receiver operating characteristic (ROC) analysis and found that the area-under-the-curve (AUC) was 0.95 (0.92 to 0.99). Sensitivity was measured at 88.4% and specificity at 91.5% with a cutoff-value of 11.2 ppb for QSM-measured susceptibility. Conclusion During routine MRI monitoring to detect new MS lesion activity, QSM can be used without gadolinium injection for accurate identification of the BBB leakage status in new T2w lesions.