The value of 1.5-T magnetic resonance (MR) imaging in diagnosing endometrial cysts and differentiating them from other gynecologic masses was prospectively evaluated in 374 female patients with clinically suspected adnexal masses. A suggestive diagnosis of endometrial cyst was made when a cyst that was hyperintense on T1-weighted images exhibited homogeneous hyperintensity on T2-weighted images. A definitive diagnosis was made when a cyst that was hyperintense on T1-weighted images exhibited hypointense signal on T2-weighted images (shading) or when the lesion consisted of multiple hyperintense cysts on T1-weighted images (multiplicity) regardless of the signal intensity on T2-weighted images. Surgery was performed in 293 patients, and confirmation was obtained in 354 lesions. MR imaging enabled accurate diagnosis of 77 of 86 endometrial cysts and exclusion of the diagnosis of endometrial cyst in 263 of 268 other gynecologic masses with or without internal hemorrhage. The overall diagnostic sensitivity, specificity, and accuracy were 90%, 98%, 96%, respectively. MR imaging seems to be an acceptable diagnostic test on which clinical decisions can be based in selecting treatment.

Magnetic resonance (MR) imaging was performed in ten patients with pituitary stalk transection who had idiopathic pituitary dwarfism. Contiguous sagittal T1-weighted images were obtained in all cases, and, in some, axial or coronal images were taken for further evaluation. On MR images, normal anterior and posterior lobes of the pituitary gland can be clearly differentiated because the posterior lobe has a characteristic high intensity on T1-weighted images. In the ten patients, the high-intensity posterior lobe was not seen, but a similar high signal intensity was observed at the proximal stump in seven patients. This high-intensity area is the newly formed ectopic posterior lobe, which secretes antidiuretic hormone just as the posterior lobe would. When the ectopic lobe completely compensates for the impaired posterior lobe, endocrinologic data indicate normal posterior lobe function. However, MR imaging can reveal the transection of the pituitary stalk and formation of the ectopic lobe.

Shifting electrically a magnetic domain wall (DW) by the spin transfer mechanism [1-4] is one of the future ways foreseen for the switching of spintronic memories or registers [5,6]. The classical geometries where the current is injected in the plane of the magnetic layers suffer from a poor efficiency of the intrinsic torques [12,13] acting on the DWs. A way to circumvent this problem is to use vertical current injection [7,8,11]. In that case, theoretical calculations [9] attribute the microscopic origin of DW displacements to the out-of-plane (field-like) spin transfer torque [17,18]. Here we report experiments in which we controllably displace a DW in the planar electrode of a magnetic tunnel junction by vertical current injection. Our measurements confirm the major role of the out-of-plane spin torque for DW motion, and allow to quantify this term precisely. The involved current densities are about 100 times smaller than the one commonly observed with in-plane currents [10].Step by step resistance switching of the magnetic tunnel junction opens a new way for the realization of spintronic memristive devices [14][15][16].We devise an optimized sample geometry for efficient current DW motion using a magnetic tunnel junction with an MgO barrier sandwiched between two ferromagnetic layers, one free, the other fixed. Such junctions are already the building block of magnetic random-access memories (M-RAMs), which makes our device suitable for memory applications. The large tunnel magnetoresistance [19,20] allows us to detect clearly DW motions when they propagate in the free layer of the stack [21]. The additional advantage of magnetic tunnel junctions is that the out-of-plane field-like torque T OOP can reach large amplitudes, up to 30% of the classical in-plane torque T IP [22,23], in contrast to metallic spin-valve structures, in which the out-of-plane torque is only a few % of the in-plane torque [24,25]. This is of fundamental importance since theoretical calculations predict that, when the free and reference layers are based on materials with the same magnetization orientation (either inplane or perpendicular), the driving torque for steady domain wall motion by vertical current injection is the OOP field-like torque [9]. Indeed, T OOP is equivalent to the torque of a magnetic field in the direction of the reference layer, that has the proper symmetry to push the DW along the free layer. On the contrary, the inplane torque T IP can only induce a small shift of the DW of a few nm. In magnetic tunnel junctions with the same composition for the top free and bottom reference layers, the OOP field-like torque exhibits a quadratic dependence with bias [22,23], which could not allow us to reverse the DW motion by current inversion. Therefore we use asymmetric layer composition to obtain an asymmetric OOP field-like torque [26,27].The magnetic stack is sketched in Fig.

The potential of magnetic resonance (MR) imaging in differentiation of adenomyosis from leiomyoma was evaluated in 93 patients who had a palpable enlarged uterus that was suspect for leiomyoma or adenomyosis. In all cases, MR images were correlated with surgical/pathologic findings. Pathologic findings showed that 71 enlarged uteri were due to leiomyoma, including one leiomyosarcoma, and 16 were due to adenomyosis. The other six patients were shown to have an enlarged uterus attributable to simultaneous involvement of both lesions. On T2-weighted images, adenomyosis appeared as an ill-defined, relatively homogeneous low-signal-intensity area embedded with sparse high-intensity spots. In contrast, leiomyomas were well-circumscribed masses with a spectrum of signal intensity. The cause of uterine enlargement was correctly diagnosed with MR images in 92 of the 93 cases. It is concluded that MR imaging is highly accurate in helping to distinguish between adenomyosis and leiomyoma in cases of enlarged uterus.

Demonstration and staging of carcinoma of the cervix with magnetic resonance (MR) imaging was evaluated prospectively in 67 patients with histologically proven lesions. Findings were correlated with surgical/pathologic results obtained within 2 weeks. MR imaging had an accuracy of 95% in demonstrating invasive disease (stage IB or higher). It was capable of depicting the location and extent of tumor invasion of cervical stroma and helped detect tumor beneath relatively normal epithelium or within the endocervical canal that had not been detected by means of colposcopic biopsy. The overall accuracy of MR imaging in staging carcinoma of the cervix was 76%, and in demonstrating parametrial status, the overall accuracy was 89%. In 39 patients with proven invasive disease, the accuracy in demonstrating parametrial status was 82%. In 13 of these 39 patients the low-signal-intensity stromal ring of the cervix on MR images was completely preserved and there were no false-positive results. MR imaging is a highly promising method for directly demonstrating and staging carcinoma of the cervix and seems to be capable of providing answers to crucial questions regarding mode of therapy.