歯根膜肉芽腫と歯根嚢胞の鑑別におけるデジタルX線撮影による密度測定

Digital radiography density measurements in differentiation between periapical granulomas and radicular cysts.

抄録

背景:

根尖性嚢胞と根尖性肉芽腫の鑑別は、治療を決定する上で非常に重要である。明確に定義されたX線学的基準がないため、区別は大きさに基づいて行われる。しかしながら、嚢胞は放射線密度に基づいて肉芽腫と区別できることが示唆されている。これまでの研究結果は相反するものであった。炎症性骨膜肉芽腫と橈骨嚢胞の鑑別におけるデジタルX線撮影による密度測定の適用可能性を検討する。

BACKGROUND: The distinction between radicular cysts and apical granulomas is a matter of considerable importance in making a treatment decision. Because there are no clearly defined radiographic criteria, the distinction is made on the grounds of size. However, it has been suggested that cysts can be distinguished from granulomas on the basis of their radiometric density. The results of previous studies have proved conflicting. To determine possibilities of application of digital radiography density measurements in differentiation of periapical granulomas and radicular cysts of inflammatory origin.

材料/方法:

20～84歳の患者を対象に、Digora、RVG、Dixi 2デジタルX線撮影システムを用いて撮影した355枚のデジタルX線写真からなり、肉芽腫259枚と橈骨嚢胞102枚の2群に分類した。Digora 2.0ソフトウェアを用いて、線に沿った最大密度と最小密度を測定し、最大密度と最小密度の差を算出した。病変の最大寸法は、根管軸に垂直および平行に測定した。

MATERIAL/METHODS: The material consisted of 355 digital periapical radiograms obtained using Digora, RVG and Dixi 2 digital radiography systems in patients aged 20 to 84, divided into two groups: 259 granulomas and 102 radicular cysts. By means of Digora 2.0 software there were measured maximum and minimum densities along a line, then there was calculated the difference between maximum and minimum density. The largest dimensions of the lesions were measured - perpendicular and parallel to the root canal axis.

結果:

線測定における最大密度と最小密度の差に基づいて、嚢胞性肉芽腫と根尖性嚢胞の鑑別がある程度可能であることが証明された - 差が85.6を超えると病変は嚢胞であり、45.9を下回ると肉芽腫と診断された。

RESULTS: It was proved that to some extent it was possible to differentiate cystic granulomas and radicular cysts on the basis of the difference between maximum and minimum density in linear measurement - when the difference exceeded 85.6 the lesion was a cyst and when it was below 45.9 a granuloma was diagnosed.

結論:

計算された密度差と病変の最大寸法という2つの基準の組み合わせは、肉芽腫と放射線嚢胞の放射線学的鑑別の診断可能性を増加させた。

CONCLUSIONS: Combination of two criteria - the calculated difference between densities and the largest dimension of a lesion, increased diagnostic possibilities of radiological differentiation of granulomas and radicular cysts.