儿童腺样体肥大的CT表现及测量方法研究

目的：探讨儿童鼻咽部腺样体肥大的CT表现、测量方法及临床应用价值。材料与方法：对50例9个月-14岁经临床确诊为腺样体肥大且行刮除手术治疗的儿童术前分别进行鼻咽部CT扫描和同层动态CT电影扫描（CINE）。通过蝶-枕骨结合部层面，测量正中矢状面腺样体最大厚度与鼻咽气腔前后径的比值（A/N）、鼻咽气腔有效气道的前后径D值、鼻咽气腔有效截面面积（Sn）、同层动态CINE扫描鼻咽气腔截面面积改变差值（△S），并与同龄同性别健康儿童进行比较。结果：①腺样体肥大在鼻咽部CT轴位上主要表现为3种形态：弥漫性肿块形、单侧肿块形、嵌入鼻后孔肿块形；②肥大组50例，A/N：0．61-0．86；D：1-2．8mm；Sn：0-97．86mm^2；△S：0—32．54mm^2；正常组50例，A/N：0．34—0．61；D：7．5—12．2mm；Sn：217．87-623．98mm^2；△S：175．87—274．02mm^2。结论：腺样体CT检查方法较X线侧位平片信息量大、鼻咽腔结构显示清晰，尤其是CINE可以帮助了解鼻咽腔随呼吸时动态变化。正中矢状面腺样体厚度与鼻咽气腔前后径的比值、鼻咽气腔有效气道的前后径D值是评价腺样体肥大的重要依据，当A/N≥0．71，D≤3mm时可视为儿童腺样体病理性肥大指征。

CT manifestation and measurement of adenoid hypertrophy in children

Objective： To explore the clinical value of CT manifestation and methods of measurement of adenoid vegetation in children. Materials and Methods： Nasopharyngeal CT plain scans and dynamic CINE CT scan were obtained in 50 children aged 9 months to 14 years with operation proved adenoid hypertrophy as study group and 50 age and gender matched children without adenoid hypertrophy as control. Measurement of maximum thickness of adenoid/anterior-posterior diameter of nasopharyngeal air space ratio （A/N ratio）, effective anterior-posterior diameter of nasopharyngeal air space （D value）, effective sectional areas of nasopharyngeal air space （Sn） and difference of Sn on dynamic CINE CT （AS） were carried out at the level of sphenoccipital junction on midline sagittal plane. Results： On the transverse CT, hypertrophy adenoid manifested as soft tissue mass that was symmetric, unilateral or embedded into choana. Measurements of study group were： A/N ratio ranged from 0.61 to 0.86, D ranged from 1 to 2.8mm, Sn ranged from 0 to 97.86mm^2 and AS ranged from 0 to 32.54mm^2. The correspondent ts of control group were 0.34-0.61, 7.5-12.2mm, 217.87-623.98mm^2 and 175.87-274.02mm^2 respectively. Conclusion： CT is much better than the lateral X-ray plain film measurement of nasopharynx in the diagnosis of adenoid vegetation for CT can provide much more information and can clearly depict the nasopharynx and CT CINE is especially useful to reflect the changes of nasopharynx with respiration. A/N ratio and D value can be used as indicators： pathologic adenoid hypertrophy should be considered when there is an A/N ratio greater than 0.71 and a D value less than 3mm.