Comparison Between Sectional Anatomy And Magnetic Resonance Imaging Of Hypothalamigray Matters

Background and objective Hypothalamus takes important place in the nerve systemof human body, lots of severe consequences can be caused by the diseases related tohypothalamus. With the development of hypothalamic function stereo positioning, theanatomy of hypothalamus is also becoming increasingly important in the treatment ofdiseases related to hypothalamus, such as hypothalamic deep electrode placement. Herewe discussed through the hypothalamus sectional anatomy and magnetic resonanceimages（MRI） of the same cases of adult specimens were observed, and furtherinvestment of head MRI of healthy adult men, ultimately find out the morphological,location and signal of the hypothalamic nucleus and the white matter fiber tract.therefore to provide basic knowledge for the morphology and signal of hypothalamicnuclei and white matter fibers tract. and also provide the diagosis of hypothalamicdisease,a new treatment diseases related to hypothalamic operation.Materials and methods:①6cases of wet head specimens are sequentially numbered,and according to the number, conventional MRI was scanned. Using the8channel headcoil inspection. Scan range: from the beginning to the parietal foramen magnum,covering the whole brain. Scanning sequences included T1WI and T2WI sequences.Magnetic resonance imaging was performed the standard axial scanning with the baseline drawed from anterior commissure to posterior commissure in No.1and No.4specimens,; No.2and No.5specimens were scanned with standard human body sagittalscan； No.3and No.6specimens with standard coronal scanning. After obtainedsatisfactory image quality, the image is saved in DICOM format.②According to thenumber and the scanning plane turn wet head specimens made corresponding axial,coronal and sagittal sectional specimen.③Organized a hypothalamic MRIexamination of10healthy adult male, scanning sequence was T1WI and T2WI, each patients underwent axial, coronal and sagittal scan. The image was saved as DICOMfile.④A camparison was made among the sectional images and MRI image of thespecimen and the MRI of the living volunteer, to identify the morphology, location andsignal characteristics of the hypothalamic nucleus and the white matter fiber.Results①the mamillary nucleus is located in mamillary body, is showed as a typicalstructure of the gray matter, white matter fiber is found around the nucleus. In themidsagittal plane it is visible that white matter fiber from fornix projectded into themammillary body nucleus. Infundibular nucleus is located between the optic nerve andthe bottom of third ventricle. Infundibular nucleus and mamillary nucleus is orderlylocated after the optic chiasm. Preoptic nucleus located in the preoptic area, showed asgray matter structure is a irregular in sagittal sectional specimens in the preoptic nucleus,including. Flake gray matter structures of supraoptic nucleus ride on supraoptic,supraoptic nucleus and periaqueductal gray structure boundary is not clear. Theparaventricular nucleus located around the third ventricle in gray matter, in the coronaryand axial plane visible.②In the specimen MRI images, mamillary nucleus was ovaland had slightly high signal in the T1WI image, the edge of the nucleus can be seen thewhite matter fibers around and projected into the nucleus;infundibular nucleus is locatedbelow the third ventricle, and before mamillary nucleus, T1WI, T2WI images showed ahypersignal structure; preoptic nucleus located in the preoptic area before the graymatter structure cross front and anterior commissure line before, T1WI, T2WI imagesshowed a hypersignal structure, the boundaries is poorly displayed; supraoptic nucleusof hypothalamus is above optic tract, and the boundaries is unclear; paraventricularnucleus is positioned by the fornix and the third ventricle, it is visible in the T1WI,T2WI images, by contrast of the surrounding white matter it has a clear boundary. Inaddition, in the sagittal plane of wet head specimens, mamillothalamic tract andmammillotegmental tract both can be found clearly in the T1WI and T2WI image, anddemonstrated as low signal cordlike structure.③According to sectional anatomy images and MRI images of the head wet specimens, may be discovered in thehypothalamic nuclei in the corresponding position can be discovered in the cranial MRIimages of healthy volunteers. however, due to the differences between wet headspecimens and cranial image of living health adult, healthy volunteers hypothalamicsignal changes significantly, in the T1WI image, the white matter was high signal, graymatter was showed as the low signal; in the T2WI image, white matter showed as lowsignal, gray matter was high signal.Conclusion MRI examination can provide accurate basis in image hypothalamusnucleus and white matter fiber inspection. To provide anatomical basis foracknowledging of the hypothalamus, and also improved the reliability in the diagnosisof the hypothalamic disease and operation of hypothalamic electrode implantation.