Theerakulpisut Daris, Somboonporn Charoonsak, Wongsurawat Nantaporn
J Med Assoc Thai. 2016 Aug;99 Suppl 5:S65-73.
Bone scintigraphy (BS) has been the mainstay in evaluating patients with mandibular condylar hyperplasia (CH). Both planar BS and single photon emission computed tomography (SPECT) have been used to determine cessation of condylar hyperactivity before corrective surgery. The present study aimed to examine the utility of the relatively new single photon emission computed tomography/computed tomography (SPECT/CT) technique for evaluation of CH.
Sixty-one mandibular Tc-99m methylene diphosphonate bone SPECT/CT studies were reviewed. Images were analyzed without and with fusion with anatomical CT. Condylar uptake were quantified and differences in uptake between the right and left condyles were determined by both maximum uptake and average uptake in the region of interes (ROI). Differences exceeding 10 percentage points indicated condylar hyperactivity.
SPECT and SPECT/CT showed positivity in 34 and 31 examinations, respectively. Agreement between the two modalities was high, but was not perfect. SPECT was found to be more reproducible than SPECT/CT. Quantification using maximum ROI counts was more reproducible than using average ROI counts.
No evidence was found to indicate superiority of SPECT/CT over simple SPECT for evaluation of condylar hyperactivity in CH, as demonstrated by the lower intra-modality reproducibility and a trend towards lower sensitivity for detection of hyperactive condyles. Utilization of SPECT alone would further benefit in terms of reduction of patient radiation exposure which is a concern, especially in younger patients such as those with CH. When using quantification, maximum ROI counts should be used over average ROI counts.
骨闪烁显像（BS）一直是评估下颌髁突增生（CH）患者的主要方法。平面BS和单光子发射计算机断层扫描（SPECT）均已用于确定矫正手术前髁突活动亢进的停止情况。本研究旨在探讨相对较新的单光子发射计算机断层扫描/计算机断层扫描（SPECT/CT）技术在评估CH中的应用价值。
回顾了61例下颌骨Tc-99m亚甲基二膦酸盐骨SPECT/CT研究。在不融合和融合解剖CT的情况下对图像进行分析。对髁突摄取进行定量分析，并通过感兴趣区域（ROI）的最大摄取和平均摄取来确定左右髁突之间摄取的差异。差异超过10个百分点表明髁突活动亢进。
SPECT和SPECT/CT分别在34例和31例检查中显示阳性。两种检查方式之间的一致性较高，但并不完美。发现SPECT比SPECT/CT更具可重复性。使用ROI最大计数进行定量分析比使用平均计数更具可重复性。
未发现证据表明SPECT/CT在评估CH中的髁突活动亢进方面优于单纯SPECT，这表现为较低的检查方式内可重复性以及检测活动亢进髁突的敏感性呈降低趋势。仅使用SPECT将在减少患者辐射暴露方面进一步受益，这是一个值得关注的问题，尤其是在年轻患者如CH患者中。进行定量分析时，应使用ROI最大计数而非平均计数。
