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The Radiofrequency Refocused Echo Spin-Echo Echo-Train Rapid-Acquisition sequences, known as Turbo Spin Echo or Fast Spin Echo are the most commonly used sequences in Magnetic Resonance as they provide a notable contribution in morphological and anatomical terms, thanks to their high spatial and contrast resolution. Furthermore, they allow a higher signal noise ratio than the other families of sequences thanks to the numerous refocusing pulses and thanks to a TR so long as to allow sampling as many K-space phase encodings as possible and with a complete recovery of the Longitudinal Magnetization. Finally, the multiple 180 ° pulses of these sequences reduce the inhomogeneities of the Magnetic Field by minimizing the phenomena of magnetic susceptibility. However, their application, especially in scanners with a high intensity of static magnetic field B0(1.5T and/or 3T)is prevented by the deposition of RF due to the long echo trains, which sometimes involve exceeding the limits of the specific absorption rate for patient safety. Over time, a common solution to the SAR problem has been the use of refocusing angles smaller than 180°(160°-140°-120°),which lead to its reduction at the cost, however, of an obvious penalty in terms of signal-to-noise ratio. In this study we present a modulation method of the Refocus Flip-Angle applied to the DP-TSE sequences in the evaluation of meniscal lesions in the study protocol of the Magnetic Resonance of the Knee, which exploits the phenomenon of the Pseudo-Steady-State(PSS), leading to a noticeable SARreduction without loss of SNR and also providing excellent contrast resolution

In the last decade, breast MRI has played a role of primary importance, as a "gold standard" method in the early diagnosis of breast cancer in high-risk women, in assessing the extent of the disease and the response to neoadjuvant chemotherapy. Currently, the 3D GRE Rapid-Acquisition sequence in dynamic acquisition without and with endovenous administration of contrast medium, is fundamental for the breast MRI protocol, as the current diagnostic approaches in Magnetic Resonance are based precisely on this sequence, able to guarantee accurate diagnostic performances detecting pathological mass and non-mass-enhancement. Ultrafast sequences are modern sequences based on the 4D Time-Resolved technique with k-space sampling modalities which allow the evaluation of post-contrast images with very high temporal resolution. The purpose of our work is to illustrate in particular the use of the 4D-THRIVE sequence implemented in our breast MRI study protocol.

Compressed Sense (CS) is a technological innovation in the field of Parallel Imaging (PI) that allows to reduce up to 50% the acquisition time per single sequence, reducing the whole duration of the MRI examination, and is based on the application of 3 principles: Incoherent k-space subsampling, sparsification transform and nonlinear iterative reconstruction. The purpose of our work was to evaluate the application of CS to the MRI protocol of the female pelvis performed for infertility, evaluating its Temporal Resolution and Signal/Noise Ratio (SNR) compared to the classic PI technique SENSE. MRI exams were performed with RM 3T scanners (Philips Ingenia, Philips Healthcare, Netherlands Eindhoven). The female pelvis MRI protocol included the following sequences: 3D PelvisView T2, 3D PelvisView T1, DWI (b0 and b1000), mDixon 3D THRIVE with ev. contrast media. The parameters of each sequence, with the exception of DWI in which the CS is not applicable, are shown in comparison between the application of Sense and Compressed Sense. The CS allows to obtain at the same spatial resolution, a protocol with faster acquisition times, correcting the effect of aliasing from data subsampling compared to conventional SENSE. In conclusion, the application of CS could bring multiple advantages in the field of MR imaging in the diagnosis of infertility in women, optimizing the image quality and the duration of each individual examination.

The purpose of our study is to evaluate the T2 weighted sequence with multishot radial sampling (Radial Acquisition Multi-shot) also known as Multivane sequence in Philips Healthcare, introduced by J.Pipe with the aim to minimize motion artifacts in Magnetic Resonance Imaging (MRI). In the field of prostate MRI the Multivane sequence is useful in non-cooperating patients and/or patients who, due to their clinical conditions (such as glaucoma, arrhythmia, and severe benign prostatic hypertrophy), have not been receiving intravenous antispasmodic agents, administered for limiting the motility of intestinal loops, particularly rectum. The Multivane sequence is based on the collection of data throughout parallel multiple lines in periodic rotation around the center of k-space and advanced mathematical reconstruction. As the data at the center of k-space (low frequency) containing signals with maximum amplitude will be continuously sampled, this trajectory will provide an excellent contrast-noise ratio (CNR) and spatial resolution, without motion artifacts responsible of "blurring" in the final image. Specifically, each given point of the periphery of the k-space will be sampled by a certain line and the next one and so on, and for the final image reconstruction, once multiple data will be estimated, different algorithms will be used to compensate for motion artifacts. In this study we compared the Radial Acquisition Multishot TSE Multivane (Philips Healthcare) with the classic T2W TSE sequences with linear Cartesian sampling. Multivane sequences have proven to be superior and therefore of greater utility compared to sequences with linear Cartesian data sampling, in patients who can not receiving spasmolytic agents.