[Usefulness of the FRFSE method in SPIO-MRI].

AIM: Super-paramagnetic iron oxide-enhanced magnetic resonance imaging (SPIO-MRI) is highly sensitive for liver tumors. This trial examined the optimal parameters of the fast recovery fast spin echo (FRFSE) method in SPIO-MRI. The FRFSE method is a pulse sequence with recovery of the compulsory longitudinal magnetization. The FRFSE method used in SPIO-MRI has better sensitivity for liver tumor, better tumor contrast, and can be used with respiratory gating. MATERIALS AND METHODS: The phantoms used included a ferucarbotran phantom, water phantom, and gelatin phantom. Each phantom was scanned by the FRFSE method and fast spin echo (FSE) method, with changing of scanning parameters, and each CNR was measured. Each CNR was given a point, and points were averaged according to each parameter. Parameters that obtained high average points were considered optimal parameters. RESULTS: The optimal parameters were set to TE=50 ms in the FRFSE method. The scan parameters optimized from the phantom study were used in a clinical case, and good results were achieved, as in the phantom study. CONCLUSION: We optimized the scan parameters of the FRFSE method and were able to suggest the usefulness of the FRFSE method in SPIO-MRI.

[Usefulness of lower extremity 2D TOF MR venography with respiratory compensation technique, and effect of patient positioning on the visualization of deep veins in the leg].

We evaluated the usefulness of two-dimensional time-of-flight (2D TOF) MR venography (MRV) of the lower extremity using the respiratory compensation (RC) technique. In addition, six variations in patient positioning of the leg and knee were investigated to determine the best method of visualizing the deep popliteal veins and lower leg. All data sets were reviewed and graded for visualization of the deep veins at the pelvis, thigh, and leg portion (4-point scale) by two radiologists and three radiological technologists. The same veins demonstrated with various positions of the patient were also evaluated in the same manner. In conclusion, 2D TOF MRV with RC resulted in increased uniformity of vein signal in the pelvic area. Furthermore, we should position the patient's leg so as not to compress the vein at the posterior portion of the leg, and not to over-extend the knee joint. This enabled the best results to be obtained in MRV of the lower extremity.