鞍区囊性病变影像学诊断

目的:探讨鞍区囊性病变的CT和MR I表现,提高对该类疾病的诊断和鉴别诊断水平。方法:收集经手术病理与临床证实的鞍区囊性病变的CT和/或MR I资料72例,其中囊性垂体瘤12例,囊性颅咽管瘤25例,Rathke囊肿16例,蛛网膜囊肿4例,鞍上池下疝继发假性蛛网膜囊肿4例,鞍旁表皮样囊肿4例,鞍旁皮样囊肿3例,垂体脓肿4例。全部病例均行CT和/或MR I平扫,其中14例行CT增强检查,58例行MR I增强检查。72例中65例经手术病理证实,7例经临床证实。结果:12例囊性垂体瘤,其中垂体大腺瘤8例,微腺瘤4例。6例大腺瘤表现为在实性瘤体内出现囊变区,2例瘤卒中囊变区内可见液平。4例囊性垂体微腺瘤显示垂体饱满,内部出现异常信号/密度,伴有化验室检查异常。25例囊性颅咽管瘤以囊性表现为主,发现囊壁钙化及强化的垂体对鉴别诊断有意义。16例Rathke囊肿信号多样,但以形态饱满,呈短T1、长T2信号为较具特征性的改变。4例蛛网膜囊肿和鞍上池下疝继发假性蛛网膜囊肿均表现为脑脊液信号,而后者囊壁出现连续或不连续薄壁环形强化,为其特征性表现。3例皮样囊肿密度/信号较表皮样囊肿复杂,压脂序列对两者鉴别诊断有帮助。4例垂体脓肿增强均显示环形强化,结合临床病史有助于术前诊断。结论:鞍区不同性质的囊性病变具有一定的影像学特点,通过详细的影像学检查可对其中多数病变做出正确的定性诊断。

Imaging Diagnosis of Rathke's Cleft Cyst

Objective: To analyse CT and MRI findings of cystic lesions in sella region and enhance the level of diagnosis and differential diagnosis for these diseases.Method: CT and MR imaging findings in 72 patients with pathologically and clinically proved cystic lesions in sella region were collected.Among all patients,cystic pituitary adenoma was found in 12 cases,cystic craniopharyngioma in 25 cases,Rathke's cleft cyst in 16 cases,arachnoid cyst in 4 cases,suprasellar cistern hernia and secondary pseudo-arachnoid cyst in 4 cases,parasellar epidermoid cyst in 4 cases,parasellar dermoid cysts in 3 cases,Abscess of pituitary in 4 cases.All the patients were examined by plain MRI and CT scan,among which 58 cases were examined by MRI contrast enhanced scan,14 cases by CT contrasted enhanced scan respectively.65 cases were proved by operation and pathology,7cases were proved by clinical data.Result:There were 12 cases cystic pituitary adenoma,in which macroadenoma 8 cases,microadenoma 4 cases.Mutiple cystic region could be found within the body of 6 cases pituitary macroadenoma with necrosis or cystogenesis.Fluid-level could be seen in 2 cases pituitary apoplexy.4 cases cystic pituitary microadenoma showed abnormal signal intensity or density within well-stacked pituitary gland,accompanied with abnormality of laboratory test.The main imaging manifestation of 25 cases cystic craniopharyngioma mainly showed cystic lesions,calcification of the capsule wall and the viewing of enhanced pituitary have value in differential diagnosis.16 cases Rathke's cleft cyst showed diverse signal intensity.However short T1,long T2 signal intensity and well-stacked shape have feature to Rathke's cleft cyst relatively.All arachnoid cyst and secondary pseudo-arachnoid cyst demonstrated CSF signal intensity.Continuous or discontinuous thin ring-like enhancement could be seen in secondary pseudo-arachnoid cyst.fat-suppression sequence was helpful in diagnosis of epidermoid cyst and dermoid cyst.The relatively thick ring-like enhancement and clinical history were helpful in diagnosis of pituitary abscess before operation.Conclusion: There were many imaging characteristics for differential category cystic lesions in sella region.It is possible to make accuracy diagnosis in majority of these lesions through detailed imaging examinations.