正常蝶鞍的CT表现

近年来,蝶鞍的放射学检查已由多轨迹断层,常规横断CT发展到冠状薄层高分辨力CT,后者能直接见到垂体腺,清楚显示垂体上缘并发现微小腺瘤。目前除MRI外,高分辨力CT是检查蝶鞍最合适的方法。为了达到早期诊断或除外鞍区病变的目的,有必要熟悉蝶鞍的正常CT表现和变异。     

多层螺旋CT诊断颅底骨折的应用价值

目的 :探讨高分辨力多层螺旋CT扫描对颅底骨折诊断价值。方法 :对 48例患者行常规轴位CT扫描与高分辨力薄层轴位扫描及直接冠状位扫描 ,比较常规轴位CT扫描与高分辨力薄层轴位扫描图像对骨折的显示率 ,同时又对薄层扫描MPR冠状位重建图像与直接冠状位扫描图像对骨折的显示进行比较。结果 :前组二者有明显差异 (P <0 0 0 1 ) ,后组图像骨折显示率无明显差异。结论 :多层螺旋高分辨力薄层CT扫描对提高颅底骨折诊断率有明显价值 ,并可替代直接冠状位CT扫描成像     

MRI半剂量动态增强扫描对垂体微腺瘤的诊断分析

目的:探讨MRI半剂量动态增强扫描技术对垂体微腺瘤的诊断价值.方法:回顾性分析经手术及临床综合诊断明确的29例垂体微腺瘤的MRI平扫及半剂量动态增强扫描资料.结果:29例垂体微腺瘤中,病灶大小小于5mm 18例,5～10mm 11例.平扫16例T1WI可见低信号影;无明显异常信号8例(其中6例病灶直径小于5mm);垂体形态异常5例;而半剂量动态增强扫描均发现病灶,表现为动态早期稍低信号影.结论:半剂量动态增强扫描MR对垂体微腺瘤的诊断有极高的应用价值,尤其是动态增强早期扫描最为敏感.     

垂体瘤的CT诊断

1972年以来,横断CT已成功地用于诊断蝶鞍病变,并取代了气脑造影,但仅能诊断1.0cm以上和鞍上延伸的病变。目前直接冠状高分辩力CT使人类首先能用放射学方法直接见到正常的垂体和腺内微腺瘤。本文对近年来垂体瘤的CT检查方法与诊断问题加以综述。检查方法直接冠状CT扫描病人仰卧,头颈尽量后仰,使OM线接近于水平。摄取侧位定位片以确定最佳角度,扫描架附加15～20°角,使扫描面与鞍底垂直。Taylor介绍在背部垫高15～20°角效果更好。扫描范围     

经海绵间窦造影诊断垂体微小腺瘤

本文为一篇应用海绵间窦造影诊断垂体微小腺瘤的初步报告。目前,放射科诊断垂体腺瘤的根据为:平片和断层片所显示的蝶鞍骨壁形态与厚度的改变以及综合应用气脑造影、颈动脉造影和 CT 扫描以显示肿瘤的鞍上延伸。而垂体微小腺瘤的诊断则主要依赖断层片和血中泌乳激素的测定。血中泌乳激素正常     

原发性垂体前叶功能低下症原因的MRI诊断

目的分析原发性垂体前叶功能低下症的MR影像特点,以明确其病因.材料与方法经临床,实验室及MR确诊的原发性垂体前叶功能低下症共21例.均行MR平扫及增强检查.结果垂体大腺瘤共9例(女3例,男6例),5例合并腺瘤出血.继发性空蝶鞍8例,均为女性,其中5例继发于微腺瘤术后,1例继发于腺瘤γ刀治疗后,2例继发于产后大出血.垂体低矮共3例(1例为儿童,2例为成年女性).垂体影像正常1例.结论原发性垂体前叶功能低下症的常见病是垂体大腺瘤和继发性空蝶鞍,MRI能为明确病因提供可靠的影像学证据.     

动态对比增强MRI诊断《5 mm垂体微腺瘤的应用研究

目的　探讨动态对比增强磁共振成像 (DCE -MRI)动态扫描时间的选择对诊断 <5mm垂体微腺瘤的影响。方法　对 3 6例经手术病理及临床治疗证实的垂体微腺瘤的MRI进行分析。使用Philips 1.5T超导磁共振仪。所有患者在常规平扫后 ,均进行DCE -MRI冠状位扫描。结果　 3 6例均呈阳性结果 ,<5mm的垂体微腺瘤由于瘤体微小平扫有时难以发现病灶 ,本组平扫 19例未发现信号学改变 ;7例未发现形态学改变 ,而动态增强扫描均能发现病灶 ,明确诊断。结论　DCE -MRI对 <5mm垂体微腺瘤的诊断极有价值 ,尤其是动态早期 ,在 3 3 .5s之前表现最为敏感 ,它是目前MR诊断垂体微腺瘤的最佳扫描方法。     

促ACTH垂体腺瘤术前CT诊断准确性的评价

作者分析了35例(男9例,女26例)临床疑有促ACTH垂体腺瘤并经手术探查患者的冠状位CT扫描资材,手术证实27例。27例中,3例为大的垂体腺瘤,术前CT诊断均正确(包括高度、上缘的形态、垂体柄移位及蝶鞍的骨质变化)。24例垂体微腺瘤中(直径<10mm)14例CT术前诊断正确,男10例则为阴性。35例术前CT检查共疑有腺瘤者20例,其中17例(85%)经手术证实,在15例术前CT检查阴性者中,10例(66.6%)手术探查发现肿瘤。冠状面CT检查诊断促ACTH腺瘤的敏感性为63%,特异性为62.5%,总的准确性为62.8%。作者认为,采用当前最新的CT装置和检查技术,柯兴氏病的术前垂体CT检查价值明显低于泌乳素     

垂体促肾上腺皮质激素腺瘤的MRI特点

目的：探讨垂体促肾上腺皮质激素（ACTH）腺瘤的MRI特点。材料和方法：回顾性分析266例垂体ACTH腺瘤的MRI特点。患者均行蝶鞍区矢状位和冠状位T1WI薄层增强和平扫，39例同时行动态增强扫描。结果：MRI显示未见异常41例（15．4％），微腺瘤179例（67．3％），大腺瘤42例（15．8％），巨大腺瘤4例（1．5％）；垂体卒中13例（4．19％）。MRI对垂体ACTH腺瘤的阳性发现率为84．6％（225／266）；动态增强的阳性发现率为87．2％（34／39）。本组MRI未见异常和明确微腺瘤的术后内分泌治愈率分别为90．0％和87．8％，两者之间无明显差别（P〉0．05）。结论：蝶鞍区冠状位增强扫描有助于垂体ACTH微腺瘤的术前定位，动态增强扫描能提高垂体微小腺瘤的术前检出率。     

鞍内病变的MR诊断

目的　通过总结 12 4例鞍内病变的MR表现 ,探讨鞍内病变的MR诊断和鉴别诊断。方法　 12 4例鞍内病变 ,均行MR平扫检查 ,84例行增强扫描。 93例经手术病理证实 ,3 1例经临床证实。结果　垂体微腺瘤 46例 ,垂体巨腺瘤 3 2例 ,Rathke囊肿 10例 ,转移瘤 4例 ,垂体脓肿 3例 ,空泡蝶鞍 2 1例 ,淋巴样垂体腺炎 2例 ,垂体腺良性增生 2例 ,蛛网膜囊肿 2例 ,特发性垂体功能低下2例。垂体腺瘤、转移瘤、淋巴样垂体腺炎、垂体腺良性增生和垂体脓肿表现为垂体腺增大 ,增强扫描和临床资料对鉴别诊断非常重要。可根据信号变化区别Rathke囊肿和蛛网膜囊肿。空泡蝶鞍的诊断要点是漏斗无移位。特发性垂体功能低下表现为垂体腺小和漏斗消失。结论　鞍内病变的MR主要表现包括垂体腺增大、鞍内囊性病变和垂体腺发育异常 ,鉴别诊断需结合信号变化、增强表现和临床资料 ,综合分析     

Gadolinium-DTPA and MR imaging of pituitary adenoma: a preliminary report

Gadolinium-DTPA MR imaging (Gd-MR), unenhanced MR imaging, and contrast-enhanced CT studies were compared prospectively in six patients with surgically confirmed pituitary adenomas and three patients without sellar pathology to determine the utility of Gd-MR in the diagnosis of pituitary adenoma. In normal patients, the pituitary gland, cavernous sinus, and infundibulum enhanced by T1 shortening after gadolinium. In adenoma patients, two of four focal lesions identified with contrast-enhanced CT were identified with Gd-MR, and one was identified with unenhanced MR. The earliest short repetition-time sequence performed after gadolinium injection was best for focal lesion detection. Normal cavernous sinus enhancement by gadolinium made identification of cavernous sinus extension of adenoma difficult. Infundibulum displacement was better seen with contrast-enhanced CT (two vs one); however, unenhanced and Gd-MR were better than contrast-enhanced CT for demonstrating chiasmal compression (four vs three). Contrast-enhanced CT, Gd-MR, and plain MR were equally able to identify gland enlargement, sellar floor erosion, and abnormalities of the diaphragma sellae. In this preliminary series, we found Gd-MR to be promising for imaging adenomas; however, modifications in Gd-MR technique including thinner slices and immediate scanning after gadolinium injection are necessary for the best detection of focal lesions.     

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.     

不典型肾上腺腺瘤的CT 影像误诊分析

目的：通过回顾性分析11例不典型肾上腺腺瘤的C T影像特征及误诊原因,以提高诊断准确率。方法收集近几年经手术病理确诊的不典型肾上腺腺瘤11例,均行C T平扫及三期增强扫描,结合临床资料进行回顾性分析。结果11例肾上腺腺瘤中,高强化腺瘤2例,肿块最大径＞4cm的大腺瘤8例,双侧腺瘤1例。高强化腺瘤在C T增强表现为快进快退;大腺瘤中囊性密度和强化较低的2例,肿瘤内出血的无功能肾上腺瘤1例,CT增强表现为快进快退伴偏心囊变的5例,双侧高强化的肾上腺腺瘤1例。结论详细分析不典型肾上腺腺瘤的CT特征,密切联系临床病史、实验室结果和M RI检查,可提高不典型肾上腺腺瘤的诊断准确率。     

Comparison of delayed enhanced CT and chemical shift MR for evaluating hyperattenuating incidental adrenal masses

PURPOSE: To retrospectively compare the accuracy of delayed enhanced computed tomography (CT) and chemical shift magnetic resonance (MR) imaging for characterizing hyperattenuating adrenal masses at CT, with either follow-up imaging or pathologic review as the reference standard. MATERIALS AND METHODS: The institutional review board approved this retrospective study with a waiver of patient informed consent. Forty-three hyperattenuating adrenal masses (>10 HU) on unenhanced CT images were found in 34 patients (23 men and 11 women; mean age, 52.7 years) by reviewing radiologic reports. These lesions were retrospectively analyzed with delayed enhanced CT and chemical shift MR. The diagnostic accuracy of CT by using absolute percentage loss of enhancement (PLE) and relative PLE and of chemical shift MR by using adrenal-to-spleen ratio (ASR) or signal intensity index (SII) were obtained to determine which modality was more accurate for lipid-poor adenoma. For CT, an adenoma was diagnosed if a mass had an absolute PLE greater than 60% and a relative PLE greater than 40%. For MR, an adenoma was diagnosed if a mass had an ASR of 0.71 or an SII greater than 16.5%. McNemar test was used to compare diagnostic performance of CT and MR. RESULTS: Hyperattenuating adrenal masses included 37 adenomas and six nonadenomas. The sensitivity, specificity, and accuracy for adenoma at CT were 97% (36 of 37), 100% (six of six), and 98% (42 of 43), respectively, and at MR were 86% (32 of 37), 50% (three of six), and 49% (21 of 43), respectively. CT helped confirm five more adenomas and three more metastatic tumors than did MR. However, there was no significant difference for diagnostic accuracy between these two imaging modalities (P>.05) CONCLUSION: Delayed enhanced CT can characterize additional hyperattenuating adrenal masses that cannot be characterized with chemical shift MR.     

The diagnosis of acromegaly: value of inferior petrosal sinus sampling

The early diagnosis of acromegaly may be difficult when serum levels of growth hormone are minimally elevated and imaging of the pituitary gland fails to show an adenoma. However, transsphenoidal surgery has the greatest chance of cure at this stage. We therefore investigated the value of sampling petrosal sinuses for measurement of growth hormone in this group of patients. Simultaneous bilateral sampling of the inferior petrosal sinuses to measure serum concentrations of growth hormone was performed in five patients suspected of having acromegaly but with nondiagnostic CT scans (n = 5) and MR images (n = 3) of the pituitary gland. Levels of growth hormone from the petrosal sinuses were five to 36 times greater than levels in the peripheral veins in all five patients, and three of four showed a marked response to growth hormone-releasing hormone. During transsphenoidal surgery, growth hormone-producing microadenomas were resected completely in four patients. In the fifth patient, a left-sided microadenoma had invaded the cavernous sinus and could not be resected completely. Lateralization of the adenomas within the pituitary gland on the basis of differences in levels of growth hormone between the two petrosal sinuses was not completely reliable. Elevated levels of growth hormone in selective samples from the inferior petrosal sinuses can help support an early diagnosis of acromegaly when peripheral growth hormone levels and imaging are not diagnostic.     

蝶窦内异位垂体腺瘤的CT和MRI诊断

目的 探讨蝶窦内异位垂体腺瘤的CT和MRI表现,并评价2种影像检查方法的临床应用价值.方法 回顾性分析8例经组织学证实蝶窦内异位垂体腺瘤的影像学资料.8例患者均经CT和MR检查.结果 8例垂体瘤均位于蝶窦,与鞍内垂体不相连;3例呈卵圆形,不规则形5例,病灶最大径20～46 mm,边界均较清楚.CT表现:与脑灰质比较,平扫呈等密度7例,稍低密度1例,其中2例增强呈较均匀中度强化;病变周围的骨质不同程度受压、变形、硬化,其中5例并可见局部侵蚀状破坏;鞍底骨质完整3例,骨质破坏5例.MRI表现:与邻近脑厌质比较,在T1WI呈稍低信号2例,等信号6例,T2WI呈稍高信号2例,等信号6例,病变信号不均匀,内散在小泡状、细条状长T1、长T2信号,对应组织学上扩大的腺泡;增强后病变不均匀低中度强化,外观近似筛网状.2例行MR动态增强扫描,时间-信号强度曲线均为速升缓降璎.5例伴有空蝶鞍,5例包绕邻近海绵窦,与邻近颈内动脉分界不清,4例侵及斜坡.结论 T2WI小泡状、细条状高信号和增强后T1WI筛网状外观是该病的特征性表现.CT和MRI联合使用能够对该病的诊断、治疗提供更全面的信息.     

多层螺旋CT对甲状旁腺腺瘤的诊断价值

目的：探讨多层螺旋CT（MSCT）对甲状旁腺腺瘤的诊断价值。方法：回顾性分析10例经手术病理证实为甲状旁腺腺瘤的CT及临床资料。结果：10例甲状旁腺腺瘤均起源于下甲状旁腺,右侧4例,左侧6例,均位于气管食管沟内。肿瘤大小约0.9cm×1.0cm～3.0cm×8.0cm,呈圆形或卵圆形,边缘光滑完整。平扫肿瘤呈等密度,较正常甲状腺为低密度。增强后10例肿瘤均有不同程度强化,但均较周围血管密度及正常甲状腺密度低,增强后肿瘤呈均匀强化者8例,坏死不均匀强化者2例。结论：MSCT增强及三维重建检查可准确显示甲状旁腺腺瘤的部位、形态、大小及其与周围结构的关系,对临床手术有重要的指导意义。     

Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

Purpose:
Multidetector-row CT is a new technology with a short scanning time. Multislice dynamic CT (MSDCT) in various directions can be obtained using the multidetector-row CT with multiplanar reformatting (MPR) technique. Material and Methods:
We evaluated the initial results of sagittal and coronal MSDCT images reconstructed by MPR (MSDCT-MPR) in 3 pituitary adenoma patients with a pacemaker. Results:
In a patient with microadenoma, the maximum contrast between the normal anterior pituitary gland and the adenoma occurred approximately 50 s after the start of the contrast medium injection. A microadenoma was depicted as a less enhanced area relative to normal pituitary tissue. The macroadenomas were depicted as a less enhanced mass with cavernous sinus invasion in 1 patient and as a non-uniformly enhanced mass in another patient. Bone destruction and incomplete opening of the sellar floor during previous surgery were clearly detected in 2 patients with macroadenomas. These pituitary adenomas were removed via the transnasal route based on information from the MSDCT-MPR images only. The findings were verified surgically. Conclusion:
The MSDCT-MPR provided the information needed for surgery with good image quality in the 3 patients with pacemakers. MSDCT-MPR appears to be a useful technique for patients with a pituitary adenoma in whom MR imaging is not available. This is the first report, to our knowledge, of the MSDCT-MPR technique being used to demonstrate pituitary disorders.     

鞍旁海绵状血管瘤的CT和MRI诊断

目的总结7例鞍旁海绵状血管瘤CT、MRI和磁共振波谱（MRS）表现，探讨其诊断和鉴别诊断。资料与方法7例均经手术病理证实，均行CT和MR平扫，2例行CT增强扫描，7例行MR增强扫描，5例行MR扩散加权成像（DWI），6例行^1H MRS检查。结果鞍旁海绵状血管瘤体积大，并同时伸入到鞍内。CT平扫病变呈等或稍高密度，密度均匀，MR T1WI呈等或稍低于脑灰质信号，T2WI呈类似脑脊液高信号。增强扫描病变呈非常显著强化。DWI呈等或稍低信号，但表观扩散系数（ADC）值明显高于正常脑实质。。HMRS表现为NAA峰、Cr峰和Cho峰消失。可出现Lip峰。结论CT检查时鞍旁海绵状血管瘤与脑膜瘤和垂体瘤鉴别困难,MRI表现很有特点，T2WI呈极高信号，增强扫描非常显著强化，ADC值明显升高而DWI接近等信号，MRS检查无NAA峰、Cr峰和Cho峰，MRI可以对海绵窦海绵状血管瘤作出定性诊断。     

骨样骨瘤的影像学诊断

目的 分析骨样骨瘤的X线、CT和MRI表现。方法 搜集经手术病理证实的骨样骨瘤48例，其中男33例，女15例。所有病例均行X线检查，其中同时行CT检查者32例，行MR检查者10例，3种检查方法都进行者8例。分析骨样骨瘤在X线、CT和MRI上的表现及其对瘤巢和瘤巢周围改变的显示能力。结果 48例病灶均表现为一圆形或卵圆形的透亮区，直径为0．4～1．7cm，平均9．7cm，其周围有不同程度的骨质硬化。10例行MR检查者均可见瘤巢周围的软组织、骨髓水肿或关节腔积液。48例X线平片仅37例显示瘤巢，32例行CT检查者均清楚显示瘤巢，X线和CT对瘤巢显示率分别为77％(37／48)和100％(32／32)。10例MR检查者均可作出正确诊断，其中8例能直接判断出瘤巢，另2例需对照平片或CT才能肯定。结论 瘤巢是确诊骨样骨瘤的关键，X线平片仍然是诊断骨样骨瘤的重要检查方法，CT是显示瘤巢的最佳方法，MRI能敏感地显示瘤巢周围骨髓内及软组织的炎性水肿，但可能造成误诊，结合平片或CT可作出准确诊断。