A comparison of CT and MRI in the assessment of the pituitary and parasellar region

We have carried out a prospective study to compare high resolution thin slice, contrast-enhanced, axial computed tomography (CT) with unenhanced magnetic resonance imaging (MRI) at 1.5T in the assessment of the pituitary and parasellar region. Forty patients with suspected pituitary disease presenting to an endocrine unit were studied. MRI was superior to CT for the identification of the posterior pituitary and pituitary stalk and was better at showing the cystic nature of tumours. Visualization of the optic chiasm and assessment of displacement of the optic chiasm and the carotid arteries were also better with MRI. CT was equally good at showing cavernous sinus displacement or invasion, sphenoid sinus invasion and erosion of the floor of the sella turcica and was the only technique able to show calcification of the gland. More focal abnormalities were seen in the pituitary gland with CT than with unenhanced MRI, but there was a higher false positive rate for microadenoma detection with CT. All the scans were interpreted separately by three observers, two radiologists and one clinician. The percentage agreement between the observers for the identification of pituitary and parasellar structures was better for MRI than for CT and the clinician in particular found interpretation of the MR images easier. MRI thus not only gives more information overall than CT but it is a more reliable technique between different observers for the assessment of the pituitary and parasellar region.     

Magnetic resonance imaging of the pituitary gland

Magnetic resonance imaging (MRI), a nonionizing, biologically safe imaging technique, is bringing the desired goal of directly imaging the pituitary gland very close to reality. The exquisite anatomic demonstration of the gland and hypophyseal stalk and the perisellar structures and the usefulness of tissue characterizations (T1 and T2 values) firmly establish the role of MRI in imaging of pituitary gland abnormalities, with the potential of becoming the procedure of choice.     

Diabetes insipidus secondary to intracranial sarcoidosis confirmed by low-field magnetic resonance imaging

A 32-year-old woman who had been diagnosed as having pulmonary sarcoidosis 18 months previously presented with thirst and polyuria. The diagnosis of diabetes insipidus was confirmed biochemically and magnetic resonance imaging (MRI) revealed sarcoid involvement of the pituitary stalk.     

MRI of pituitary adenomas following treatment

The purpose of this study was to assess pituitary adenomas following surgical and/or medical treatment in 28 patients. All patients were evaluated with both computed tomography (CT) and magnetic resonance imaging (MRI). The results were correlated with the clinical findings. Apart from the visualization of the adenoma itself (either residual or recurrent) other findings and in particular, morphological changes of the optic chiasm, the pituitary stalk and the sellar floor were evaluated with both imaging modalities.By comparing the two imaging modalities it was found that MRI was superior to CT in demonstrating residual/recurrent adenoma as well as evaluating the morphological changes of the optic chiasm and optic nerves. CT was superior or equal to MR in demonstrating the sellar floor changes. The intra-operatively implanted fat was equally seen by CT and MR.In conclusion, the anatomical variations of the optic chiasm and pituitary stalk are better visualized by MRI and allow a more precise evaluation of changes attributed to surgical or medical treatment of pituitary adenomas. Correspondence to: A. Gouliamos     

Congenital diseases of the thoracic aorta. Role of MRI and MRA

Aortic malformations may be associated with other congenital heart abnormalities or may present independently, as incidental findings in asymptomatic patients. For more than 30 years, conventional imaging techniques for detection and assessment of congenital anomalies of the aorta have been chest X-ray, echocardiography and angiography. In recent times, considerable interest in congenital aortic diseases has been shown, due to technical progresses of noninvasive imaging modalities. Among them, magnetic resonance imaging (MRI) almost certainly offers the greatest advantages, especially in young patients in which a radiation exposure must be avoided as much as possible. MRI provides an excellent visualization of vascular structures with a wide field of view, well suited for evaluation of the thoracic aorta malformations. With the implementation of magnetic resonance angiography (MRA) it is also possible to depict any relationship with supra-aortic or mediastinal vessels. Phase contrast technique allows identification of the hemodynamic significance of the aortic alteration. Some technical considerations, which include fast spin-echo, gradient-echo and, especially, MRA techniques with phase-contrast and contrast enhanced methods, are discussed and applied in the evaluation of congenital thoracic aorta diseases.     

胎儿体蒂异常的MRI表现及病理对照

目的:探讨胎儿体蒂异常的MRI表现及诊断价值.方法:对5例超声诊断体蒂异常的胎儿于3天内行MRI检查,3例在我院引产后回顾分析其MRI表现并行病理对照,2例在外院引产.结果:5例胎儿MRI均显示有复杂畸形,5例均有较大的胸腹壁或腹壁缺损、内脏器官疝入羊膜腔、脊柱异常及脊柱侧后弯、脐带无或过短伴单脐动脉.5例分别并发其它...     

MR imaging in idiopathic growth hormone deficiency.

BACKGROUND AND PURPOSEMR imaging findings of one or more of the following has been suggested to be a sensitive and specific indicator of hypopituitarism: small anterior pituitary gland, attenuated or absent pituitary stalk, and ectopic posterior pituitary. We hypothesized that these MR findings would be common in our group of patients with idiopathic isolated growth hormone deficiency (GHD) or multiple pituitary hormone deficiencies (MPHD) and would be a good indicator of the severity of the hypopituitarism.METHODSMR images were obtained for 35 patients with idiopathic GHD (20 with isolated GHD and 15 with MPHD; age range, 2 to 17 years) and analyzed to define one or more of the following triad of abnormalities: 1) small/absent anterior pituitary, 2) truncated/absent pituitary stalk, and 3) ectopic posterior pituitary, as well as for any other associated anomalies. The findings were correlated with the clinical and biochemical presentation.RESULTSPituitary abnormalities were common in both groups (80% with isolated GHD, 93% with MPHD). We found a high frequency of midline CNS malformations, including optic nerve hypoplasia (9%), Chiari type I malformations (20%), and medial deviation of the carotid arteries (37%). Breech delivery, neonatal hypoglycemia, jaundice, micropenis, or single central incisor occurred equally with both isolated GHD and MPHD. In patients whose peak growth hormone level was less than 3 microg/L (n = 19), 90% had the MR triad, compared with 390% of those with growth hormone levels 3 microg/L or greater or less than 8 microg/L (n = 13) (P <.01). Almost all (92%) of those with ectopic posterior pituitary had anterior pituitary heights less than -2 SD for age.CONCLUSIONMR abnormalities were common in children with both isolated GHD and MPHD and were closely associated with peak growth hormone levels less than 3 microg/L. The presence of other CNS and clinical findings (eg, single central incisor and micropenis) supports the theory of an embryologic defect as the cause of the pituitary abnormalities.     

Magnetic resonance imaging of thickened pituitary stalk proceeding to Langerhans cell histiocytosis in a child

Magnetic resonance imaging has shown isolated pituitary stalk thickening in certain cases of idiopathic or secondary central diabetes insipidus (DI) due to infiltrative processes. We present a 4-year-old boy who was initially diagnosed as having central DI. The MRI showed isolated pituitary stalk thickening with prominent homogeneous contrast enhancement. The remaining findings on MRI were within normal limits. The patient's personal and family history and laboratory and clinical findings were unremarkable; therefore, he was initially diagnosed as having idiopathic DI. Since central DI and isolated pituitary stalk thickening may be considered to be the first manifestations of Langerhans cell histiocytosis, we decided to follow up the patient. After 5 months, following the initial diagnosis, on skeletal X-ray survey, the patient did indeed develop multiple lytic skull lesions which, on biopsy, were histologically typical bone lesions of Langerhans cell histiocytosis.     

Computed tomography and magnetic resonance imaging of congenital abnormalities of the temporal bone

Congenital abnormalities of the temporal bone are mostly accompanied by conductive or sensori-neural hearing loss. Before any therapeutic procedures are done high resolution CT (HRCT) and magnetic resonance imaging (MRI) should be performed to establish the correct diagnosis and to plan the potentially surgical intervention. HRCT best depicts osseous changes especially those of the external auditory canal and the middle ear containing the ossicles and the osseous structures of the temporal bone and the petrous bone containing the inner ear. MRI excellently shows soft tissue changes of the inner ear especially on the high resolution 3DT2-weighted sequences which give a superb contrast between the nerves and the cerebro-spinal fluid. Malformations of the external auditory canal consists of aplasia or hypoplasia and those of the middle ear range form extreme hypoplasia or aplasia to very mild deformations of the ossicles. Malformations of the inner ear also range form complete aplasia to very mild hypoplasia of the organs of the inner ear as well as malformations concerning the nerves in the internal auditory canal range from aplasia to hypoplasia. Malformations of the temporal bone can either occur isolated or in combination in which malformations of the external and middle ear may be accompanied by those of the inner ear. Furthermore, malformations of the temporal bone may also occur in otofacial, otocervical or otoskeletal syndromes. These syndromes may be accompanied by certain malformations of the temporal bone. HRCT and MRI are both excellent methods to depict congenital abnormalities of the temporal bone and of the inner ear and should be used as complementary methods because HRCT best depicts osseous changes and MRI superbly depicts soft tissue changes. Both methods are important to establish the correct diagnosis to plan the therapeutic procedures.     

Primary hypothyroidism with pituitary enlargement and a visual field abnormality.

A 23 year old man presented with classical hypothyroidism of 9 years duration. This was associated with pituitary enlargement, documented on magnetic resonance imaging (MRI), and abnormal half-field visual evoked responses (VERs). Following the initiation of thyroxine therapy the pituitary enlargement and the VER abnormalities resolved. The final diagnosis was of primary hypothyroidism with secondary pituitary hyperplasia.     

Imaging of the pituitary in children with growth disorders

Magnetic resonance imaging reveals the anatomy of the pituitary and hypothalamus with unique detail. The clinical and biochemical investigation of short stature in childhood may be difficult and complex; magnetic resonance imaging of the pituitary is a non-invasive technique which can help to clarify the diagnosis of growth hormone insufficiency and to determine its cause. Most cases of growth hormone insufficiency have previously been considered to be idiopathic; in about 60% of these children, magnetic resonance imaging shows a characteristic structural abnormality which has been termed pituitary stalk interruption syndrome. The most important role of magnetic resonance imaging is in the diagnosis of destructive lesions of the hypothalamic-pituitary axis which may initially present with growth failure.     

MRI对先天性心脏病解剖及功能评价

目的　探讨MRI对先天性心脏病 (CHD)解剖及功能评价的临床应用价值。方法　对 1 5例经手术证实的CHD患者超声心动图 (ECG)与MRI诊断结果进行对比分析 ,研究 2种技术检测心脏解剖与功能的作用。结果　 1 5例患者 2 4个畸形中 ,MRI诊断正确 2 0个 (2 0 / 2 4 ) ,ECG诊断正确 2 1个 (2 1 / 2 4 )。MRI显示心外大血管病变较ECG有优势 ,而ECG显示心脏瓣膜病变较清晰 ;MRI和ECG在检测左心室舒张末期横径、容积 ,左心室收缩末期容积 ,左心室搏出量以及射血分数时 ,2种技术无显著性差异。结论　MRI可较准确地检测CHD的解剖和功能异常     

Magnetic resonance imaging in patients with panhypopituitarism

Primary panhypopituitarism consists of functional deficiency of the anterior pituitary lobe, which appears during infancy or adolescence. The magnetic resonance findings in 10 patients with a history of primary hopopituitarism are presented. The findings include: reduced pituitary size in all cases: partially (8 cases) or totally (2 cases) empty sella; thin (4 cases), partially visible (3 cases) or absent (2 cases) pituitary stalk; absence of the posterior lobe in 9 cases: bright spot corresponding to an ectopic posterior lobe in 8 cases. These findings are similar to those already reported in pituitary dwarfism and may help under-genesis of the pathogenesis of the disease: which seems to he related to a pituitary stalk lesion.     

MRI of the foetal brain

Ultrasound examinations for foetal brain abnormalities have been a part of the routine antenatal screening programme in the UK for many years. In utero brain magnetic resonance imaging (MRI) is now being used increasingly successfully to clarify abnormal ultrasound findings, often resulting in a change of diagnosis or treatment plan. Interpretation requires an understanding of foetal brain development, malformations and acquired diseases. In this paper we will outline the technique of foetal MRI, relevant aspects of brain development and provide illustrated examples of foetal brain pathology.     

Hypophysentumoren

Background and objectives

This article gives an overview of the most common tumors of the pituitary gland and the differential diagnostics with special emphasis on radiological diagnostic criteria.

Material and methods

A selective search of the literature in PubMed was carried out.

Results

Pituitary adenomas constitute 10–15?% of all intracranial tumors and are the most common tumors of the sellar region. Tumors smaller than 1 cm in diameter are called microadenomas while those larger than 1 cm in diameter are called macroadenomas. Approximately 65?% of pituitary gland adenomas secrete hormones whereby approximately 50?% secrete prolactin, 10?% secrete growth hormone (somatotropin) and 6?% secrete corticotropin. Other tumors located in the sella turcica can also cause endocrinological symptoms, such as an oversecretion of pituitary hormone or pituitary insufficiency by impinging on the pituitary gland or its stalk. When tumors spread into the space cranial to the sella turcica, they can impinge on the optic chiasm and cause visual disorders. A common differential diagnosis of a sellar tumor is a craniopharyngeoma. In children up to 10?% of all intracranial tumors are craniopharyngeomas. Other differential diagnoses for sellar tumors are metastases, meningiomas, epidermoids and in rare cases astrocytomas, germinomas or Rathke cleft cysts

Conclusion

As these tumors are located in an anatomically complex region of the skull base and are often very small, a highly focused imaging protocol is required. The currently favored modality is magnetic resonance imaging (MRI) with the administration of a contrast agent. The sellar region should be mapped in thin slices. In cases of suspected microadenoma the imaging protocol should also contain a sequence with dynamic contrast administration in order to assess the specific enhancement characteristics of the tumor and the pituitary gland.     

Neuroimaging in posttraumatic hypopituitarism

Posttraumatic hypopituitarism is the failure of the hypothalamic-pituitary axis secondary to traumatic brain injury. It can clinically present as decreased muscle mass, concentration, libido, and fertility. It can also present as increased fatigue, depression, and cognitive deficits. In addition, electrolyte abnormalities such as hyponatremia can occur in hypopituitarism. As a result of heightened awareness of posttraumatic hypopituitarism, it is a phenomenon that is becoming more commonly diagnosed. Posttraumatic hypopituitarism is a diagnosis based on clinical evaluation, laboratory testing, and neuroimaging. Of the radiological techniques, magnetic resonance imaging is the preferred technique to image the pituitary gland. This article contains coronal and sagittal magnetic resonance imaging of the posterior fossa, illustrating the normal hypothalamus and pituitary gland as well as adjacent structures. The sequential enhancement pattern of the normal pituitary gland is consistent with its vascular supply. A colored illustration was created to display the vascular supply to the hypothalamus, pituitary stalk, and pituitary gland.     

MRI in paediatric hypoxic-ischemic disease, metabolic disorders and malformations-a review

MRI has become the most important modality in paediatric neuroimaging. It provides an excellent anatomical overview with good spatial and temporal resolution, allows investigations of the blood vessels, and - using technologies such as diffusion-weighted imaging and magnetic resonance spectroscopy - it allows quick and exact differentiation of ischemic, hypoxic, inflammatory, oncologic, traumatic and metabolic diseases. This review presents an overview of brain MRI in infants and children with suspected hypoxic-ischemic disease, metabolic disorders or (vascular) malformations, illustrating these issues by some MRI findings in selected important conditions and discussing some major clinical and pathophysiological aspects important for imaging.     

胎儿三维磁共振成像技术的初步应用

目的：探讨三维磁共振成像（3D-MRI）技术在显示胎儿体表正常解剖和先天畸形方面的应用价值。方法：对40例18~37周的胎儿在超声检查后1~2d内行MRI检查,应用单次激发快速自旋回波序列（SSFSE）行胎儿轴面、矢状面和冠状面二维MRI（2D-MRI）,三维稳态进动快速成像（3D-FIESTA）序列MRI,均使用并行采集技术（ASSET）,在工作站对原始数据进行多平面重组（MPR）、容积重组（VR）和磁共振仿真内窥镜技术（MRVE）等三维图像后处理。将MRI和随访、尸检结果进行比较。结果：36例孕妇3D-MRI检查成功率为94.4%（34/36）,34例胎儿经随访和尸检证实46处畸形。胎儿体表先天畸形2D-MRI正确诊断37处,诊断符合率80.4%（37/46）;误诊1处,假阳性率为2.1%（1/46）;漏诊8处,漏诊率17.4%（8/46）。3D-MRI正确诊断43处,诊断符合率93.5%（43/46）;误诊1处,假阳性率2.1%（1/46）;漏诊2处,漏诊率为4.3%（2/46）。两种方法诊断胎儿体表先天畸形差异无统计学意义（χ2=2.40,P〉0.05）,但3D-MRI对于面部畸形如唇裂和其他复杂畸形如体蒂异常、骶尾部畸胎瘤、联体双胎等显示更直观清楚。结论：3D-MRI一次扫描可直观反映胎儿体表结构的表面特征、立体形态及相互间的位置关系,VR、MRVE对胎儿正常面部、外生殖器、脐带、肢体等的评价有较高价值,MPR可对兴趣区进行多角度观察。磁共振三维成像对显示胎儿正常体表结构和病变及产前咨询和围产期手术具有重要的临床价值。     

Early second-trimester diagnosis of body stalk anomaly by fetal magnetic resonance imaging

We report a case of body stalk anomaly detected prenatally by fetal magnetic resonance imaging (MRI) at 14 weeks’ gestation. A 29-year-old woman was followed during her first pregnancy. At 11–12 weeks’ gestation, our sonographic images showed multiple fetal deformities. An abdominal wall defect was suspected. The exteriorized abdominal contents and the lower limb appeared within the extraembryonic celom with an intact amniotic membrane. Fetal MRI at 14 weeks’ gestation confirmed a large anterior wall defect with herniation of the liver and bowel. In addition, abnormally rotated lower limb and scoliosis could be demonstrated. The fetus was prenatally diagnosed with body stalk anomaly, expected to be lethal in nature. The parents decided to terminate the pregnancy at 15 weeks’ gestation. Prenatal diagnosis of body stalk anomaly is usually based on sonographic findings. As far as we are aware, this is the first case report of body stalk anomaly satisfactorily diagnosed by fetal MRI in the early second trimester. Fetal MRI scans should provide ground for a precise antenatal diagnosis of body stalk anomaly from early gestation.     

垂体柄阻断综合征的MRI表现

目的讨论垂体柄阻断综合征的MRI特点。资料与方法回顾性分析临床及MRI诊断的18例垂体柄阻断综合征患儿的影像及临床资料。结果 18例患者垂体前叶明显变薄,垂体柄缺如16例,2例垂体柄纤细,垂体后叶短T1信号未见,下丘脑漏斗处有短T1信号。实验室检查均有生长激素和(或)其他激素的缺乏。结论垂体柄阻断综合征多发生于男性,有典型的MRI表现。