PURPOSE: A numerical method of designing a multiple quantum filter (MQF) is presented for the optimum detection of myo-inositol (mI), an important brain metabolite, by using in vivo proton nuclear magnetic resonance spectroscopy ((1)HMRS). MATERIALS AND METHODS: Starting from the characterization of the metabolite, the filter design includes the optimization of the sequence parameters such as the two echo times (TEs), the mixing time (TM), and the flip angle and offset frequency of the 3rd 90 degrees pulse which converts multiple quantum coherences (MQCs) back into single quantum coherences (SQCs). The optimized filter was then tested both in phantom and in human brains. RESULTS: The results demonstrate that the proposed MQF can improve the signal-tobackground ratio of the target metabolite by a factor of more than three by effectively suppressing the signal from the background metabolites. CONCLUSION: By incorporating a numerical method into the design of MQFs in 1HMRS the spectral integrity of a target metabolite, in particular, with a complicated spin system can be substantially enhanced.
Brain ; Humans ; Magnetic Resonance Spectroscopy ; Protons ; Spectrum Analysis

Objectives: To evaluate the side effects and causes of discontinuation of either combined oral contraceptives or dienogest (DNG) used to prevent recurrence in patients with surgically confirmed endometriosis. Methods: We retrospectively analyzed the medical records of 213 women with endometriosis who had been treated with combined oral contraceptives (ethinyl estradiol 0.02 mg/drospirenone 3 mg [EE/DRSP]) or DNG 2 mg for 12 months or more. The side effects reported by the patients, laboratory parameters, causes of discontinuation of medication, and recurrence rates were evaluated one, two, three, four, and five years after starting medication (Y1, Y2, Y3, Y4, and Y5). Results: EE/DRSP were administered to 59 patients, while DNG was administered to 154 patients. The mean durations of postoperative use of EE/DRSP and DNG were 44.5 ± 22.6 months and 23.6 ± 13.5 months, respectively. The prevalence of side effects was 27.1%, 19.0%, 10.0%, 10.5%, and 7.4% in the EE/DRSP group and 29.2%, 15.7%, 14.0%, 23.1%, and 0.0% in the DNG group at Y1, Y2, Y3, Y4, and Y5, respectively. The discontinuation rates were 1.7%, 1.7%, 4.0%, 0.0%, and 7.4% at Y1, Y2, Y3, Y4, and Y5, respectively, in the EE/DRSP group and 10.4%, 3.3%, 4.0%, 3.8%, and 0.0% at the same times in the DNG group. The recurrence rates were less than 4% in both the groups. Conclusions The side effects of commonly prescribed postoperative hormone treatments were relatively mild, and the occurrence of side effects decreased with continuous administration. Further, the long-term use of postoperative hormone treatments is likely to prevent recurrence of endometriosis after surgery.