The usefulness of 1.5-T high-field intraoperative magnetic resonance (iMR) imaging during transsphenoidal surgery for functioning pituitary adenomas was retrospectively evaluated based on longterm endocrine remission from the records of 14 patients who underwent transsphenoidal surgery with iMR imaging for functioning pituitary microadenomas and small adenomas located in the intrasellar region. The maximum tumor diameter was 9.3 ± 2.6 mm. Patients were diagnosed with acromegaly (n ＝ 7), prolactinoma (n ＝ 4), and Cushing's disease (n ＝ 3). If iMR imaging detected tumor remnants after resection, the resection cavity was reexamined and further resection was performed. Postoperative endocrine follow-up period was mean 33.7 ± 13.3 months. Tumor remnants were detected after the first resection in seven patients. Further resection was performed in five of these patients, and three achieved long-term endocrine remission. As a result, the overall long-term endocrine remission rate was 78.5% (11/14), instead of the 57.1% (8/14) that would be expected if iMR imaging had not been performed. Long-term endocrine remission had a tendency to be associated with the absence of tumor remnants on the final iMR images, but this was not significant (p ＝ 0.09). Long-term endocrine remission was associated with presence of tumor remnants in the cavernous sinus on the final iMR images (p ＝ 0.03). High-field iMR imaging is useful for depicting tumor remnants after resection, and increased the long-term endocrine remission rate for patients with functioning pituitary microadenomas and small adenomas.

Endoscope biopsy guided navigation for intra-parenchymal lesions is safe and effective, but determination of the entry point and trajectory of the endoscopic biopsy is less clear. We describe preoperative planning based on stereotactic methods, and achieving the plan using several techniques. The preoperative planning was based on stereotactic methods such as determining target, entry point, and trajectory. A transparent sheath was advanced under guidance of the navigation system and specimens collected under visual endoscopic monitoring. After collecting specimens, intraoperative magnetic resonance imaging was performed for confirming accurate sampling. Correct specimens were obtained in 6 cases as confirmed by intraoperative magnetic resonance imaging. The histological diagnoses were diffuse large B-cell type malignant lymphoma (n ＝ 3), astrocytoma (n ＝ 1), glioblastoma (n ＝ 1), and inflammatory changes without neoplastic cells (n ＝ 1). No postoperative intracranial hemorrhage or other operative complications occurred. Preoperative planning based on stereotactic methods and procedures guided by navigation systems can achieve endoscopic biopsy for intraparenchymal lesions safely and accurately.

A 47-year-old man presented to our hospital after suffering transient loss of consciousness and falling to the floor. On admission, his Glasgow Coma Scale score was 11 (E3V3M5), and he exhibited restlessness. Blood examination revealed hyperthyroidism. Computed tomography showed slight traumatic subarachnoid hemorrhage. He developed fever and tachycardia, and was diagnosed with thyroid crisis. Magnetic resonance imaging showed a brain contusion in the right frontal lobe, and encephalopathy signs in the right frontal and insular cortex. Immunocytochemical examinations suggested Hashimoto's disease, and hormone examinations revealed plasma levels were undetectably low of adrenocorticotropic hormone (ACTH) and low of cortisol. Pituitary stimulation tests showed inadequate plasma ACTH and cortisol response, consistent with isolated ACTH deficiency (IAD). The final diagnosis was IAD associated with Hashimoto's disease. Hydrocortisone replacement therapy was continued, and the patient was nearly free from neurological deficits after 18 months. The neuroimaging abnormalities gradually improved with time.

Magnetic resonance imaging (MRI) is superior to computed tomography (CT) in determining changes in tissue structure, such as those observed following inflammation and infection. However, when metal implants or other metal objects are present, MRI exhibits more distortion and artifacts compared with CT, which hinders the accurate measurement of the implants. A limited number of reports have examined whether the novel MRI sequence, multiacquisition variable-resonance image combination selective (MAVRIC SL), can accurately measure metal implants without distortion. Therefore, the present study aimed to demonstrate whether MAVRIC SL could accurately measure metal implants without distortion and whether the area around the metal implants could be well delineated without artifacts. An agar phantom containing a titanium alloy lumbar implant was used for the present study and was imaged using a 3.0 T MRI machine. A total of three imaging sequences, namely MAVRIC SL, CUBE and magnetic image compilation (MAGiC), were applied and the results were compared. Distortion was evaluated by measuring the screw diameter and distance between the screws multiple times in the phase and frequency directions by two different investigators. The artifact region around the implant was examined using a quantitative method following standardization of the phantom signal values. It was revealed that MAVRIC SL was a superior sequence compared with CUBE and MAGiC, as there was significantly less distortion, a lack of bias between the two different investigators and significantly reduced artifact regions. These results suggested the possibility of utilizing MAVRIC SL for follow-up to observe metal implant insertions.