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Pituitary gland, also called hypophysis, ductless gland of the endocrine system that secretes hormones directly into the bloodstream. The term hypophysis (from the Greek for “lying under”)—another name for the pituitary—refers to the gland’s position on the underside of the brain. The pituitary gland is called the “master gland” because its hormones regulate other important endocrine glands—including the adrenal, thyroid, and reproductive glands (e.g., ovaries and testes)—and in some cases have direct regulatory effects in major tissues, such as those of the musculoskeletal system. 垂体，又称脑垂体，内分泌系统中无导管的腺体，直接向血液中分泌激素。垂体这个词（来自希腊语，意为“躺在下面”）——垂体的另一个名称是指腺体在大脑底部的位置。垂体被称为“主腺”，因为它的激素调节其他重要的内分泌腺，包括肾上腺、甲状腺和生殖腺（如卵巢和睾丸），在某些情况下，它对主要组织（如肌肉骨骼系统）有直接的调节作用。 The pituitary gland lies at the middle of the base of the skull and is housed within a bony structure called the sella turcica, which is behind the nose and immediately beneath the hypothalamus. The pituitary gland is attached to the hypothalamus by a stalk composed of neuronal axons and the so-called hypophyseal-portal veins. Its weight in normal adult humans ranges from about 500 to 900 mg (0.02 to 0.03 ounce). 垂体位于颅底的中部，位于一个叫做蝶鞍的骨质结构内，蝶鞍位于鼻子后面，紧接着在下丘脑下面。垂体通过一个由神经元轴突和所谓的垂体门静脉组成的柄与下丘脑相连。它在正常成人中的重量约为500到900毫克（0.02到0.03盎司）。 In most species the pituitary gland is divided into three lobes: the anterior lobe, the intermediate lobe, and the posterior lobe (also called the neurohypophysis or pars nervosa). In humans the intermediate lobe does not exist as a distinct anatomic structure but rather remains only as cells dispersed within the anterior lobe. Nonetheless, the anterior and posterior lobes of the pituitary are functionally, anatomically, and embryologically distinct. Whereas the anterior pituitary contains abundant hormone-secreting epithelial cells, the posterior pituitary is composed largely of unmyelinated (lacking a sheath of fatty insulation) secretory neurons. 在大多数物种中，垂体被分成三个叶：前叶、中间叶和后叶（也称为神经垂体或神经部）。在人类中，中间叶不作为一个明显的解剖结构存在，而只作为分散在前叶内的细胞存在。尽管如此，垂体的前叶和后叶在功能上、解剖上和胚胎上是不同的。垂体前叶含有大量分泌激素的上皮细胞，而垂体后叶则主要由无髓（缺乏脂肪绝缘鞘）分泌神经元组成。 The pituitary gland is a dual-supplying organ, similarly: the liver: the hepatic and portal veins; the lungs: the pulmonary and bronchial arteries; the brain: the internal carotid and vertebral arteries; the adrenal: the adrenal arteries and renal arteries. 垂体是双重供血器官，类似的还有：肝脏：肝动脉和门静脉供血；肺：肺动脉和支气管动脉；脑：颈内动脉系统和椎动脉系统；肾上腺：肾上腺动脉和肾动脉。 The blood supply to the pituitary gland is complicated. The pituitary artery first descends through the pituitary funnel to reach the anterior pituitary gland to form the pituitary portal system. 'The normal anterior pituitary gland passes through the pituitary portal system and indirectly supplies its blood from the pituitary arteries. The blood supply to the posterior pituitary is directly from the neck The branch of the internal artery. Therefore, during dynamic enhancement, the posterior lobe and the funnel are strengthened at the earliest stage. Because the anterior pituitary is indirectly supplied with blood through the pituitary portal system, it is slower than the posterior lobe during dynamic enhancement. The enhancement is later than the above. The blood supply of pituitary microadenomas is also different. It is generally believed that the blood supply is from the pituitary portal system, probably due to the slow blood flow in the tumor. 'The peak of microadenoma enhancement is slower than normal pituitary , Showing a low signal. However, there is evidence that a small number of pituitary microadenomas are directly supplied by the internal carotid artery, so,In the early stage of dynamic enhancement, it showed a high signal '. Therefore, in the early stage of dynamic enhancement, the diagnosis of pituitary microadenomas is the most effective. In order to better display the pituitary microadenomas, the imaging time is generally within 2 minutes. 垂体的血供比较复杂。上下垂体动脉首先通过垂体漏斗部下降到达垂体前叶形成垂体门脉系统'。正常垂体前叶通过垂体门脉系统,由上下垂体动脉来间接供给其血液。垂体后叶的血液供应直接来源于颈内动脉的分支。因此,动态增强时,最早期是后叶及漏斗部强化,垂体前叶由于是通过垂体门脉系统间接供血的,所以在动态增强时比后叶强化慢。垂体周边部的强化更晚于上述部位。垂体微腺瘤的血供也有不同。一般认为是由垂体门脉系统供血,大概由于肿瘤内的血流缓慢的缘故',微腺瘤增强的高峰比正常垂体要慢,表现为低信号。但有证据表明少数垂体微腺瘤由颈内动脉直接供血,所以在动态增强早期强化,表现为高信号”。因此,在动态增强早期的影像对垂体微腺瘤的诊断是最有效的。为了更好地显示垂体微腺瘤,造影时间一般要在2分钟以内。 Scanning plan of pituitary gland 垂体的扫描方案 1. Locate the coronal plane in the sagittal plane image, the positioning line is parallel to the pituitary stalk, adjust the angle in the cross section, and adjust the left and right and up and down positions of the FOV in the coronal plane to make the image center symmetrical. 2. Conventionally adopt 140-180mmFOV, RL phase coding, 9-12 layers (including full pituitary and saddle structure), layer thickness / spacing: 3mm / 0.3mm, if the lesion penetrates can increase the layer thickness or number of layers 3. T1WI COR sequence can add parallel saturation bands before and after respectively, the purpose is to reduce vascular pulse artifacts. 1.在矢状面图像定位冠状面，定位线平行于垂体柄，横断面调整角度，在冠状面上调整FOV左右与上下的位置，使图像居中对称； 2.常规采用140-180mmFOV，RL相位编码，9-12层（包全垂体及鞍旁结构），层厚/间距：3mm / 0.3mm，如病灶穿透可增加层厚或层数； 3. T1WI COR序列可分别在前后分别加平行饱和带，目的是减少血管搏动伪影。 4. Using SE sequence scan, in order to ensure the display of small lesions in the pituitary, TSE technology is generally not recommended; 5. Thin-field scanning with small field of view to ensure good observation of pituitary structure; 6. The diagnosis of pituitary mainly depends on T1WI. 4. 采用SE序列扫描，为保证垂体内微小病变显示，通常不建议使用TSE技术; 5. 采用小视野薄层扫描，保证垂体结构得到良好观察; 6.垂体的诊断主要依赖T1WI。 The normal pituitary has no blood-brain barrier, and the enhancement can occur in the early stage after the injection of contrast agent, while most microadenomas are supplied by the portal system of the pituitary, and the enhancement is slower than that of the normal pituitary. In the early stage after the injection of contrast agent, the enhancement is weak or not, and the delayed stage is stronger than that of the normal pituitary. 正常的垂体无血-脑屏障,在注射造影剂后的早期即可发生强化,而大多数的微腺瘤由垂体的门脉系统供血,其强化比正常垂体慢,在注射造影剂后早期表现为弱强化或不强化,延迟期较正常垂体强化。 Most literatures in the industry indicate that the full-contrast angiography scan (0.1mmol / kg) will reduce the contrast between normal pituitary and progressively enhanced pituitary microadenomas, so it is recommended to use half-dose (0.05mmol / kg) angiography scan for dynamic enhancement scanning.Half dose dynamic contrast-enhanced scan and delayed contrast-enhanced scan have high application value in the diagnosis of pituitary microadenoma, which can be used as a routine imaging method for the diagnosis of pituitary microadenoma. 业内多数文献表明：全计量造影扫描方式（0.1mmol/kg）会降低正常垂体与逐渐强化的垂体微腺瘤之间的对比度，故推荐使用半剂量（0.05mmol/kg）造影扫描方式进行动态增强扫描。半剂量动态对比增强扫描和延迟对比增强扫描在垂体微腺瘤的诊断中具有较高的应用价值，可作为常规的影像学方法诊断垂体微腺瘤。 After a few days, we will similarly recommend a cardiac magnetic resonance scanning protocol to you. 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