CT scan of pituitary adenomas

Summary CT scan is an extremely useful, almost harmless means of diagnosing pituitary adenomas. Growth hormone (GH)-secreting adenomas tend to have higher absorption coefficient on plain CT than the nonfunctioning and prolactin (PRL)-secreting adenomas. The absorption coefficient on contrastenhanced CT does not identify the specific type of adenoma. Ring-like enhancement was observed in five nonfunctioning and four PRL-secreting adenomas with suprasellar extension, while cystic components were observed in four nonfunctioning and four PRL-secreting adenomas. In three of ten cases of PRL-secreting microadenomas, the site corresponding to the adenoma was not enhanced, whereas the normal pituitary was. A correlation exists between the size of PRL-secreting adenoma and the serum PRL level, but not between the size of GH-secreting adenomas and the serum GH level.     

Evaluation of pituitary macroadenomas with multidetector-row CT (MDCT): comparison with MR imaging

Introduction It is important to have information on cavernous sinus extension and bony destruction in pituitary macroadenomas before surgery, but magnetic resonance (MR) imaging cannot always depict them. In the present study we sought to determine whether multidetector-row computed tomography (MDCT) could provide preoperative information in addition to that provided by MR imaging in pituitary macroadenoma. Methods The subjects comprised 33 consecutive patients (15 women, 18 men; mean age 50 years) with surgically proven macroadenoma. For MDCT, using the soft-tissue window and bone window, three orthogonal multiplanar reconstruction images were generated from venous-phase contrast-enhanced 0.5-mm isotropic voxel data. MDCT and MR images were evaluated with regard to: (1) clarity of tumor margins; (2) identification of the normal pituitary gland; (3) identification of erosion or destruction of the sellar floor; and (4) visualization of the adjacent optic pathways. Results MDCT more clearly demonstrated the lateral tumor margin than MR imaging (P = 0.002). No significant differences in visualization of the normal pituitary gland were noted between MDCT and dynamic MR imaging (P = 0.7). MDCT more clearly demonstrated sellar floor erosion or destruction at the sphenoid sinus than MR imaging (P < 0.001). MR imaging was superior to MDCT for visualizing the adjacent optic pathways (P < 0.001). Conclusion MDCT is superior to MR imaging for assessing lateral tumor margin and the sellar floor at the sphenoid sinus. MDCT offers useful preoperative information in addition to that obtained from MR imaging. Y.M. and M.K. contributed equally to this study.     

Magnetic resonance imaging of pituitary adenomas

Today, MR is the only method needed for the morphological investigation of endocrine-active pituitary adenomas. In acromegaly and Cushings syndrome, the therapeutic attitude is directly dictated by MR data. We present the MR aspect of pituitary adenomas according to size, sex, age, endocrine activity and a few particular conditions such as hemorrhagic pituitary adenomas, pituitary adenomas during pregnancy, cavernous sinus invasion and postsurgical changes. When an intrasellar mass extending out of the sella turcica is detected, the goal of the MR examination is to indicate precisely the origin of the tumor, its extension in relation to the various surrounding structures, its structure and its enhancement in order to help in the differential diagnosis. Demonstration of very small pituitary adenomas remains a challenge. When SE T1- and Turbo SE T2-weighted sequences are non-diagnostic, enhanced imaging becomes mandatory; half-dose gadolinium injection, delayed sequence, dynamic imaging can be of some help.     

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     

MRI of pituitary adenomas in acromegaly

Adenomas causing acromegaly represent at least a quarter of pituitary adenomas. We studied 12 patients presenting with active acromegaly due to a pituitary adenoma with a 1.5 T superconductive MRI unit. All had T1-weighted sagittal and coronal sections before and after Gd-DTPA; six had coronal T2-weighted images. Surgical correlation was obtained in seven patients. Histologically, there were eight growth hormone (GH)-secreting and three mixed [GH and prolactin (PRL) secreting] adenomas, and one secreting GH, PRL and follicle-stimulating hormone. Macroadenomas (10) were more frequent than microadenomas (2). No correlation was found between serum GH and tumour size. There were nine adenomas in the lateral part of the pituitary gland; seven showed lateral or infrasellar invasion. Homogeneous, isointense signal on T1- and T2-weighted images was observed in six cases. Heterogeneous adenomas had cystic or necrotic components. Received: 29 April 1996 Accepted: 8 August 1996     

Diagnosis of small and micro pituitary adenomas by intercavernous sinus venography

Summary Intercavernous sinuses surround the pituitary gland and their form can be modified by small pituitary tumors. A preliminary report of the use of venography for the diagnosis of pituitary microadenomas is presented.     

Imaging of giant pituitary adenomas

We present five proven giant pituitary adenomas studied by CT and MRI, and review the clinical and imaging findings. Our aim was to examine the radiologic appearances and to search for criteria useful in distinguishing these tumors from other sellar and suprasellar tumours, mainly craniopharyngioma. The main differences from small adenomas were high prevalence of macrocysts, a more invasive behaviour and a clinical picture dominated by mass effect rather than endocrine disturbance. Factors supporting the diagnosis of pituitary adenoma in a giant intra- and suprasellar mass include: infrasellar extension, absence of calcification and presence of low-signal cysts on T1-weighted images. Received: 13 October 1997 Accepted: 25 February 1998     

CT of the normal pituitary gland

Summary Retrospective evaluation of the pituitary gland on coronal post-contrast CT scan in 251 patients demonstrated that the pituitary gland is somewhat larger in females than in males. In males, glands measuring greater than 7.7 mm should be considered abnormal; in females, a statistically significant decline of gland height occurs with increasing age, the upper limit of normal for female gland height decreasing from 9.2 cm for a 20-year-old to 6.0 cm for a 90-year-old. Focal low densities greater than 3 mm are rare in males and probably should be considered abnormal.     

A clinical and histopathological study of factors affecting MRI signal intensities of pituitary adenomas

Our aim was to elucidate the factors which determine the MRI signal intensities of pituitary adenomas. We examined 51 patients with surgically-confirmed pituitary adenomas. Using a spin-echo pulse sequence (SE 500/15), coronal and sagittal images (3 mm slices) were obtained. Signal intensities on T1-weighted images were measured in the parenchyma of the adenoma and in normal grey matter. The relative intensity of the adenoma was assessed by calculating the ratio of its signal intensity to that of the normal grey matter of the same patient. Parafin-embedded sections were used for haematoxylin and eosin staining. The number of cells in a prescribed area was counted, and the mean of five such counts was taken as the cell density. Immunohistochemically stained sections using antibodies for various pituitary hormones were similarly examined; the ratio of the total number of hormone-positive cells to the overall total number of adenoma cells was calculated. Four independent variables were used in the analysis: the age of the patient, the maximum diameter of the adenoma, the cell density and the proportion of hormone-positive cells in the adenoma and, with the signal intensity ratio as the dependent variable, a multiple regression analysis was performed. This revealed that the the greatest influence upon the signal intensities on T1-weighted images was the proportion of hormone positive cells.     

The value of paramagnetic contrast agent gadolinium-DTPA in the diagnosis of pituitary adenomas

Summary The purpose of this study was to assess the role of MR imaging and the paramagnetic contrast agent Gadolinium-DTPA(Gd-DTPA) in the diagnosis of pituitary macroadenomas. 44 macroadenomas were examined with MRI before and after intravenous application of Gd-DTPA. Gd-DTPA produced excellent enhancement of solid adenoma. The best contrast between adenoma and surrounding structures could be gained on post-Gd T1-weighted images. Post-Gd images were equivalent to pre-Gd images in the evaluation of supra-and infrasellar extensions of macroadenomas. Post-Gd images had advantages in the evaluation of cavernous sinus invasion by adenoma. The difference in degree of contrast enhancement between adenoma and cavernous sinus facilitated the exact evaluation of lateral extension by adenoma in 18 cases. Almost equal degree of enhancement of both structures impaired tumor-sinus contrast in 2 cases. In the other 24 cases the tumor filled the cavernous sinus completely. It is our opinion that Gd-DTPA can be used on a widespread basis because of its excellent capability to highlight and delineate pituitary adenomas.     

多层CT重建技术在鼻骨骨折中的应用价值

目的探讨多层CT(MSCT)重建技术在鼻骨骨折中的临床应用。方法对60例颌面部骨折患者进行MSCT薄层扫描,并均采用三维表面遮盖成像法、多平面重建法和容积再现法对原始图像进行三维重建。结果 60例患者中单纯线型骨折12例,粉碎性骨折18例;单纯性鼻骨骨折8例,鼻骨骨折伴有骨缝分离6例,鼻骨复合性骨折16例。CT三维成像均能够清晰、立体地显示骨折的位置、形态、范围和类型以及空间关系。结论 MSCT重建图像对面部骨折的定位、定性诊断具有很高价值,为外科整复手术提供了直观的参考。     

新疆地区垂体瘤患者血管内皮生长因子表达研究

目的探讨新疆地区垂体瘤患者血管内皮生长因子（Vascular endothelial growth factor,VEGF）的表达及其意义。方法选择我院所收治的52例垂体瘤患者,其中未复发者29例,复发者23例,应用免疫组化法对其脑垂体瘤中VEGF表达进行检测。结果 52例中,有42例出现VEGF表达阳性,复发组垂体瘤中VEGF表达较未复发组明显增高,两组间差异有统计学意义（P〈0.05）。结论 VEGF在垂体瘤血管形成中发挥重要作用,可能促进垂体瘤的复发。     

MRI of pituitary adenomas: the position of the normal pituitary gland

The position of the normal pituitary gland, assessed using gadolinium-enhanced MRI was compared with the position found at surgery for pituitary adenoma in 25 patients. The tumours were five microadenomas and 20 macroadenomas. Using T1-weighted imaging, the anterior lobe could be differentiated on the sagittal image in five patients (20%) and on the coronal image in four (16%). The high intensity of the posterior lobe could be differentiated using T1-weighted sagittal imaging in 13 patients (52%). The normal pituitary gland, which enhanced more strongly than tumour, could be differentiated using Gd-DTPA-enhanced MRI on the sagittal images in 22 cases (88%) and on the coronal image in 17 (68%). In seven patients, the normal pituitary gland surrounded the tumour; it was displaced superiorly in 14 cases and superioposterorly in two but in no case was it displaced anteriorly or downwards.     

Neuroradiological manifestations of suprasellar pituitary adenomas,meningiomas and craniopharyngiomas

Summary The radiological manifestations of 16 pituitary adenomas, six meningiomas and 14 craniopharyngiomas were reviewed. The differential diagnosis of these tumors is possible with a few exceptions when skull radiography, CT, angiography and metrizamide cisternography are carefully evaluated. Prolonged injection angiography (PIA) is particularly important for demonstrating the contours of pituitary adenomas and meningiomas. Metrizamide cisternography is indicated when the tumor contours are obscure using PIA, or when the differential diagnosis is uncertain.     

Role of PROPELLER diffusion-weighted imaging and apparent diffusion coefficient in the evaluation of pituitary adenomas

Objective

The relationship between tumor consistency and apparent diffusion coefficient (ADC) values is controversial. We evaluated the role of the ADC using an advanced diffusion-weighted imaging (DWI) technique. We employed periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) DWI acquired on a 3-T magnetic resonance imaging (MRI) scanner to assess the consistency of pituitary adenomas and examined the relationship between the ADC and the hormone secretion status of the tumors and their MIB-1 labeling index (MIB-1 LI).

Materials and methods

The study protocol was approved by our institutional review board. We retrospectively studied 24 operated patients with pituitary adenomas who had undergone PROPELLER DWI on a 3-T MRI scanner. Conventional MRI findings were expressed as the ratio of the signal intensity (SI) in the lesions to the SI of the normal white matter and the degree of contrast enhancement. Minimum-, mean-, and maximum ADC (ADC_min, ADC_mean, ADC_max) values were calculated. The consistency of the tumors was determined by neurosurgeons. All surgical specimens were submitted for histological study to calculate the MIB-1 LI and the percent collagen content. Preoperative MRI-, intraoperative-, and histological findings were analyzed by a statistician.

Results

Our study included 15 soft-, 5 fibrous-, and 4 hard tumors. Tumor consistency was strongly associated with the percent collagen content. However, neither the tumor consistency nor the percent collagen content was correlated with MRI findings or ADC values. The SI of growth hormone-producing adenomas on T2-WI was lower than of the other pituitary adenomas studied (p < 0.01); no other significant difference was found in the ADC or on conventional MRI between pituitary adenomas with different secretory functions. The MIB-1 LI of pituitary adenomas was not correlated with their appearance on conventional MRI or their ADC values.

Conclusion

Using the PROPELLER DWI technique we confirmed that the ADC was not correlated with the consistency of pituitary adenomas. We also demonstrate that the ADC was not associated with the hormone-secreting status or the MIB-1 LI of pituitary adenomas.     

经单侧鼻腔经蝶显微手术切除脑垂体腺瘤

目的：研究分析经单侧鼻腔、经蝶显微手术切除垂体腺瘤的手术操作及术后处理,方法：对45例不同大小垂体腺瘤采用经鼻蝶手术,均行CT扫描及内分泌检查,其中肿瘤高径1．0－3．5cm者39例,视力视野障碍者34例,发生瘤卒中2例。结果：行肿瘤全切35例,大部分切除8例,部分切除2例,无死亡,经3个月－4．5年（平均2．1年）随访,无肿瘤复发,大部或部分切除者保持稳定。结论：经单侧鼻腔、经蝶显微手术切除3．5cm以内的垂体腺瘤是一种安全有效的方法。     

ECG-gated multislice spiral CT for diagnosis of acute pulmonary embolism

AIM: The purpose of this study was to determine the feasibility of echocardiogram (ECG)-gated multi-slice CT angiography (MCTA) in patients with clinical suspicion of acute venous thromboembolism (VTE), to investigate the effect of ECG-gating on cardiac motion artefacts, and to determine the diagnostic reader agreement of ECG-gated MCTA in comparison with conventional MCTA. MATERIALS AND METHODS: Forty-eight consecutive patients were prospectively enrolled and randomly underwent ECG-gated (n=25, group 1) or non-ECG-gated (n=23, group 2) eight-slice pulmonary MCTA. Image data were evaluated by three independent chest radiologists with respect to the presence or absence of emboli at different arterial levels (main, lobar, segmental, and subsegmental arteries), and with regard to cardiac motion artefacts. Statistical tests used to calculate inter-observer agreement were weighted kappa statistics, extended kappa statistics and confidence indices indicating three-reader agreement accuracy. RESULTS: Twenty-seven patients (56.3%) were diagnosed to have pulmonary embolism (13 from group 1, 14 from group 2). Cardiac motion artefacts were significantly more frequent in group 2 (70% in group 2 versus 13% in group 1, p=0.0001). The overall diagnostic agreement was excellent with both MCTA techniques (three-reader confidence index for all vascular territories: 0.76 and 0.84 for groups 1 and 2, respectively (extended kappa=0.69 and 0.78, respectively); three-reader confidence index for diagnosis of VTE: 0.94 and 0.85 for groups 1 and 2, respectively (extended kappa=0.91 and 0.73, respectively), weighted kappa=0.81-0.83 and 0.92-0.95 for groups 1 and 2, respectively, and did not differ significantly between the two groups. In addition there was no significant difference of inter-observer agreement in either group at any assessed pulmonary arterial level. CONCLUSION: ECG-gated pulmonary MCTA is feasible in patients with clinical suspicion of VTE. However, ECG-gated image acquisition did not influence the diagnostic reader agreement accuracy and inter-observer agreement of MCTA. Hence, it does not appear to be advantageous for the MCTA diagnosis of pulmonary embolism.     

垂体瘤动态增强MRI影像技术研究进展

国外自20世纪80年代以来，以影像学MRI诊断垂体瘤的报道日渐增多，本文仅就MRI影像技术在垂体瘤诊断中的应用做一综述，以期了解国外MRI对垂体瘤诊断的研究进展，从而进一步探讨垂体瘤的MRI诊断技术。     

MRI of ectopic posterior pituitary bright spot with large adenomas: appearances and relationship to transient postoperative diabetes insipidus

MRI of large pituitary adenomas has revealed that a posterior pituitary bright spot (PPBS), comprising ADH-containing neurosecretory granules, is commonly ectopic before surgery and attached to the tip of the pituitary stalk late after surgery. Although the PPBS indicates functional integrity of the posterior lobe, transient diabetes insipidus (DI), caused by deficiency of ADH, is frequent early after surgery. We attempted to clarify how the shape, signal intensity and site of the PPBS before surgery are related to transient DI in the early postoperative period. We carried out MRI on 15 patients with a large adenoma and an ectopic PPBS before surgery and then within 1 week (early), 1–2 months (intermediate) and 6 or more months (late) after the operation. There were nine who had transient DI, which subsided by the intermediate study; none had permanent DI. Regardless of transient DI, the PPBS was visible, and its signal intensity was similar, on all postoperative studies. Although 11 did not change in shape, four showed a remarkable change from a flat shape before surgery to a rounded one postoperatively. On the intermediate MRI, the PPBS had descended to the level of the diaphragma as mass effect disappeared.     

多层螺旋CT对卵巢恶性肿瘤的术前分期

目的: 评价多层螺旋CT对卵巢恶性肿瘤术前分期的价值.材料和方法: 用Toshiba Aquilion 多层螺旋CT扫描仪对47例卵巢恶性肿瘤患者行术前分期,并与手术病理结果对照分析.结果: 多层螺旋CT对于卵巢恶性肿瘤分期总准确率为85.1%.Ⅰ期准确率为69.2%,Ⅱ期为66.7%,Ⅲ期为89.3%.结论: 多层螺旋CT是卵巢恶性肿瘤术前分期较可靠和准确的影像检查方法.